Tuesday, 21 June 2022

Giggle at Meerkats of Addo Elephant National Park

There’s a good chance of seeing adorable meerkat youngsters. Few animals have the charisma of the diminutive meerkat. To properly appreciate their antics, head to a park such as Addo, in South Africa. Meerkat social life is built around a pack of ten to thirty members. The day starts with a session of grooming before a foraging expedition. A sentry is posted to cry out if a hawk flies over, but if a ground predator appears the pack jumps up and down together to give the illusion that they’re charging. Otherwise their day is spent tousling, rolling around, and playing ‘follow the leader’. Everyone pays attention to the pups that emerge from the burrows after January, and the pack takes turns at nursery duty.


Monday, 9 May 2022

Namibia: Struggle for Independence, 1970-1990

There is a view (expressed in the work of Lauren Dobell [1998], for example) that the struggle for independence in Namibia was largely fought outside the country, chiefly by the diplomacy of the externally based South West African People’s Organization (SWAPO) leadership. 

Within the country, certainly, SWAPO faced massive organizational problems, not only because of the way the population was dispersed across the land but also because the group’s attempts to organize were met with harsh repression and violent reactions. Nevertheless, at certain moments the internal struggle played an important role in the process which eventually led to independence. One of these moments came in 1971. 

After the International Court of Justice ruled that South Africa’s rule of the territory was illegal, the two main Lutheran Church leaders wrote an open letter to the South African prime minister, John Vorster, which presented a stance of open support for independence; this was the first time that the churches had identified themselves with the movement for independence. Within months, from December 1971 to March 1972, a major strike took place that involved up to 13,000 contract workers, the backbone of the Namibian labor force. The external SWAPO leadership was taken by surprise by the scale of the strike but quickly tried to capitalize on it. 

The new political consciousness born from the strike helped motivate the SWAPO Youth League to campaign against the imposition of the Bantustan policy in the north. The increasing resistance within the country to South African rule, and the threat of further mass action, undoubtedly played a part in the Vorster government’s decision to shift ground and accept the idea of independence for the de facto colony. But South Africa wanted to control that process, to bring into the office an independent Namibia—a government that would support, and not challenge, South African interests. 

SWAPO was never banned in Namibia because of the international status of the territory, but its internal leadership suffered constant harassment at the hands of the South African authorities, and on a number of occasions its key officials were jailed; some of them were tortured and in September 1989 a top official was assassinated. As the increasingly vicious war in the north intensified, repression elsewhere grew harsher. 

But in the mid-1980s, thanks to the reform program of the South African government, new space opened up for protest politics. The South African government knew that without international recognition of Namibian independence, the conflict with SWAPO would not end. 

It was not prepared to implement the Western plan for a transition to independence, accepted by the United Nations in September 1978, because it would almost certainly bring into office a SWAPO government, and it sought to create in the territory an anti-SWAPO front that could form an alternative to SWAPO. It, therefore, influenced a group of internal parties to form the Multi-Party Conference (MPC) in 1983, a wider grouping than merely the Democratic Turnhalle Alliance, which had won the internal election of December 1978. The MPC then pressed for the establishment of a Transitional Government of National Unity (TGNU), which came into office in June 1985. There was no new election, but to give the TGNU some legitimacy, more freedom of expression was allowed, and SWAPO began to organize as it had not been able to for over twenty years. 

It now again held mass rallies, and new leadership, returned from imprisonment on Robben Island, organized the first effective trade unions. The Namibian Union of Mineworkers under Ben Ulenga formed the backbone of the National Union of Namibian Workers, and the SWAPO Youth League gained a new lease of life. 

In the crucial year 1988, when South Africa, at last, began negotiating the implementation of the Western plan, there were widespread protests within the country, beginning in the north, where scholars at schools next to army bases protested against their proximity to the bases and called a school boycott. The school boycott spread throughout Ovamboland and into other areas, and workers began to give their support to the students. 

This growing internal crisis was one factor, argues Brian Wood, for the South African decision to go ahead with the implementation of the Western plan and to withdraw from Namibia. After a delay of over a decade, implementation began on April 1, 1989, and a large United Nations presence entered the country to supervise the election that took place in the first week of November that year. 

SWAPO emerged victoriously, but with only 57.4 percent of the vote, and not the two-thirds majority that would have enabled it to write the constitution for the new country on its own. By February 1990 the new constitution had been accepted, and the country became independent on March 21, 1990. Any account of the road to that independence must allow some space for internal resistance and mass protest in extremely difficult circumstances.

Thursday, 5 May 2022

Chrysopidae (Green Lacewings)

Chrysopidae, with its 1200 recognized species, is one of the two large families of Neuroptera, second only to the Myrmeleontidae. The larvae of many chrysopid species feed on insect and mite pests of agricultural crops or horticultural plantings and because of their value in biological control, chrysopids are the most frequently studied of the Neuroptera. Adults are medium-sized to large, delicate insects with four subequal wings (forewing length 6 – 35 mm) and relatively long, filiform antennae.

In most species the adults are green with large golden eyes, but some species have black, brown, or reddish adults). Larvae vary in shape and habits; some are voracious, active, and more-or-less generalist predators, with sleek, fusiform bodies (thus the name“ aphislions”). Others are slow-moving, cryptic, trash-carrying predators with bulbous bodies, elaborate tubercles, and long, hooked setae; they are usually associated with specific types of ant-tended prey. 
Still others live in ant nests where they feed on the inhabitants; they have rotund, bulbous bodies, greatly shortened appendages, and a dense covering of stiff, hooked setae that hold protective trash on the body. Currently, the Chrysopidae comprises three subfamilies (Nothochrysinae, Apochrysinae, and Chrysopinae); all three are only weakly supported by molecular data and only the first is well defined on the basis of adult and larval characters. Systematic and comparative biological studies are needed to clarify the taxonomy and phylogenetic relationships of the chrysopidtaxa and also to facilitate their use in biological control. Given the wide range of morphological and behavioral variation among chrysopid larvae, it is clear that inclusion of all life stages is crucial for advancing the systematics of the family. 
Recent studies of previously unknown larvae have led to changes in the tribal assignments and the recognition of new Neotropical genera. However, except for the European and Japanese faunae where larvae of approximately 80% of the species are described, the world’s chrysopid larvae are poorly known. The Nothochrysinae includes only nine extant genera; it is believed to be the basal chrysopid lineage, but molecular data have not confi rmed this opinion. 
Defining characteristics occur in the adult and larval stages; however, larvae from very few genera are known. Apochrysinae may be monophyletic, but more supporting data are needed. The larvae of one apochrysine species have been described, but distinguishing subfamilial traits were not apparent. 
The subfamily contains the largest and visually most spectacular green lacewings; its 13 genera are based largely on somewhat variable characters in wing venation. Biological studies are needed. The large subfamily Chrysopinae encompasses over 97% of the known chrysopid species; it includes 60 genera distributed among four tribes, at least two of which are poorly defined and probably not monophyletic. The tribe Chrysopini is the largest and least well known; it contains almost all of the lacewings of economic importance. 
As a group, the Chrysopidae is cosmopolitan; similarly, all of the subfamilies are widely distributed. Nevertheless, many of the genera have limited geographic distributions. For example, among the Apochrysinae, two genera occur only in Africa, four in the Neotropics, six in the Oriental region or Australia, and one in the eastern Palearctic. Most genera of Nothochrysinae are endemic to small geographic ranges; many species are known solely from a very few specimens. 
The genera within Chrysopinae range from cosmopolitan to narrowly endemic. Typically, chrysopid eggs are laid at the end of long stalks, either singly, in groups, or in clusters with the stalks loosely or tightly intertwined. The egg stalks can be naked or they may bear oily droplets; the droplets contain nutrients or defensive substances that protect the egg or the newly hatched larva from natural enemies. 
Larvae of some chrysopid species have fairly large prey ranges; they may feed on homopterans, lepidopteran eggs or larvae, and a variety of soft-bodied arthropods. But, contrary to popular lore, some species have evolved a very strong association with a particular type of prey. In Chrysopa , prey specialization can be restricted to a single species of prey and is based on a suite of intrinsic and extrinsic factors, including maternal oviposition behavior, egg size, larval morphology and behavior, phenotypic plasticity in life-history traits, responses to natural enemies that are associated with specific prey, and phenology. 
Studies indicate that prey association, such as that in Chrysopa , and also habitat association, as shown in Chrysoperla , can evolve in a manner that is very similar to the evolution of host specifi city in phytophagous insects; there is good evidence that both can be involved in speciation. Adults of most chrysopid genera feed on honeydew and pollen; in these lacewings, the dorsal crop diverticulum has numerous tracheae and is filled with symbiotic yeast. 
These symbiotes provide essential nutrients that are deficient in the diet. Adults in a few genera are predacious. In some species, adults emit foul-smelling defensive odors when they are disturbed. Some chrysopid species are multivoltine, others are univoltine; most enter diapause and undergo dormancy (hibernation, aestivation) during unfavorable (e.g., cold, hot, or dry) seasons. 
The diapausing stage (free-living larva, prepupa, or adult) varies among lacewings and is a characteristic of the genus. Some chrysopids that diapause as adults undergo seasonal color changes that appear to refl ect the background color of their habitat during the unfavorable season. Although lacewings are not considered especially strong flyers, they can move considerable distances with the wind. 
In species that diapauses as adults, there is a seasonal pattern to movement between habitats. Photoperiod often provides very important cues for timing lacewing dormancy and seasonal movement; temperature, moisture, and food can also be signifi cant factors. The genetic basis for lacewing responses to seasonal cues has been demonstrated; some exhibit geographical variability and epistasis. Chrysopine lacewings have two modes of hearing. 
The “ear” (tympanal organ) is at the base of the radial vein in each forewing. It is the smallest tympanal organ known, and it receives the ultrasonic signals of insectivorous bats. Ultrasonic signals at low rates (1–50 pulses per second) cause the lacewing to cease flight and to fall. As the bat continues to approach, its signal increases in frequency; the high-frequency signal causes the lacewing to flip its wings open quickly and fl y, thus aiding its escape. 
The second type of hearing, the perception of low-frequency, substrate-borne sounds that are emitted during courtship, is accomplished through scolopidial organs in the legs. Such sounds are an integral part of courtship in Chrysoperla species; variation in the production and perception of these sounds may have a role in speciation. 
The endemic complex of green lacewings on the Hawaiian Islands, belonging to the genus Anomalochrysa , has evolved several unique characteristics and exhibits an extraordinary range of variation in morphology and behavior. For example, unlike any other known chrysopids, Anomalochrysa females lay sessile (unstalked) eggs, either singly or in batches. Larval body shapes range from fusiform with greatly reduced lateral tubercles and few, short setae, to flattened with well developed lateral tubercles and numerous, long, robust setae. 
In continental lineages, such broad variation is found only among genera. In some species, adults or larvae are very bright and colorful; in others they are dull or resemble bird feces. Males and females may produce conspicuously loud clicking sounds during courtship and mating; how these sounds are produced and perceived is unknown. 
Some species in the genus Chrysoperla are mass-reared for release in the biological control of agricultural and horticultural pests. Among those in North America are Chrysoperla carnea and Chrysoperla rufilabris. These species possess characteristics that are advantageous for mass-rearing. For example, adults do not require prey, but will reproduce when fed artificial diets; they can be stored for long periods without significant loss of reproductive potential; and larvae can develop when fed artifi cial or factitious prey. 
Larvae of Ceraeochrysa species, which are trash-carriers, share many of the above traits that subserve mass production. They have the added advantage of being camouflaged and thus protected from their own natural enemies, for example, ants. The role of lacewings in pest management, whether naturally occurring or augmentative, is far from fully exploited.

Tuesday, 19 April 2022

What Exactly is Aquaponics?

What Exactly is Aquaponics? Aquaponics is a technique that combines many of the benefits of hydroponic setups for growing fresh fruits and vegetables by leveraging fish waste as food for your indoor garden. Not only do you end up with organic produce, you also can harvest fresh fish from the comfort of your own home (depending on the type of fish used). Hydroponic systems rely on providing nutrient rich water directly to the root systems of plants. Not grown in a soil medium, these plants require elaborate plumbing systems to operate but typically produce higher yields in a shorter period of time than traditional soil farming. 

The biggest drawback to hydroponics, however, is the need to add artificial nutrient solutions on a regular basis. Because the plants are not able to draw nutrients from the soil, hydroponic farmers and gardeners need to duplicate these conditions using chemicals that allow the plants to grow. Aquaponics is very similar to hydroponics in the way nutrients are delivered to the plants. What sets aquaponics apart as a unique, futuristic solution for long-term indoor gardening is the source of the nutrients required by the plants. 

Instead of adding synthetic chemical solutions to water, aquaponics systems rely on fish waste to produce yields that can be as much as four times larger than traditional growing methods. Fish excrete solid waste as well as ammonia through their breathing process. In their natural state, these waste products are not beneficial to plant life. However, aquaponics systems rely on helpful bacteria to convert ammonia into nitrates and nitrites that can be used by the plants as food. An aquaponics system has a variety of components inherent to its design that mimic the natural order of the ecosystem throughout the world. 

Fish tanks are used to house fish while they grow to maturity. These fish are fed on a daily basis and produce solid waste and ammonia as byproducts of their metabolic process. A pump moves this water at a regular interval from the fish tanks into the grow beds of the system. These grow beds are filled with inert medium such as crushed granite, expanded clay, or a variety of synthetic materials. The ammonia-rich water floods the grow beds. Aerobic bacteria digest ammonia and produce nitrogen-based products as part of the metabolic process; leaving these helpful plant nutrients in the growing medium. Worms are usually added to the growing medium as well. 

These animals are able to break down solid fish waste into usable plant food as a result of their metabolic process. A drainage system allows water to drain back into the fish tank. The digestive processes that occur in the grow bed convert the ammonia enriched water (which is harmful to fish in large concentrations) into nitrates used by the plants. These nitrates are harmless to the fish. The process that occurs in the grow bed acts like a biofilter making the water suitable for the fish. This constant cycle of filtration and conversion mimics natural processes and represents a truly sustainable option for producing food.

Thursday, 7 April 2022

Raccoon Dog

The Raccoon Dog is native to East Asia; it was brought to European Russia at the beginning of the nineteenth century and has since spread to other parts of Europe. Because of the white area around its snout, it strongly resembles a Raccoon, but the black band on its face is broken into two parts. The forehead is light, and an even lighter, almost white area stretches over the entire neck. The ears have dark borders, the back is mottled grey with dark stripes. 

The chest, belly, and legs are black, the tail is unstriped and dark on top, light underneath. The legs are all the same length. Raccoon Dog is about 60–80 cm long, and the tail measures up to 20 cm. Its height at the shoulder is 20–30 cm, and it weighs up to 10 kg. The Raccoon Dog’s thick fur exaggerates its true size. Raccoon Dogs live in deciduous or mixed forest with thick underbrush, usually near water or swamps, and in open landscapes with wet areas and areas with bush cover. 

It is not a shy animal, so you might also see it near or in inhabited areas.Raccoon Dogs do not hibernate, but like Eurasian Badgers, they remain in their den for several days if there is a severe frost or heavy snow. The prints of Raccoon Dog always show four toes set an equal distance from the central pad print, as well as clear claw marks. 

The front footprint is 4–5.5 cm long and about 4.5 cm wide, the rear footprints are somewhat smaller, 4–4.5 cm long and about 3.5 cm wide; the stride is about 40–60 cm. The tracks can resemble those of a fox, although the latter are more elongated. There is essentially no visible difference between the tracks of a domestic dog and those of a Raccoon Dog, and the latter may also be confused with the tracks of a domestic cat, even though the cat’s footprints never show claw prints. 

A male and female often hunt together, and one often sees the prints of two animals in the same place. The footprints are often found on the muddy shores of lakes or streams or in marshy areas. At the water’s edge, one may often also find paths that are regularly used by the animals.A Raccoon Dog can dig its own den, but it will also use old Eurasian Badger and fox dens, or live in natural cavities: in hollow trees, under roots, or between stones and rocks. One will almost always find the remains of prey close by. 

Raccoon Dogs live in family groups in established territories, which are, however, not defended vigorously. Like Raccoons and Eurasian Badgers, Raccoon Dogs are omnivores, but they consume mainly small rodents. The scat is somewhat twisted, 5–8 cm long, 1.5– 2 cm thick, and often contains much hair. It resembles domestic dog scat, but is left in piles—in latrines near the burrow or along the edge of territory. 

Beware! Raccoon Dog scat should not be touched since it can contain eggs of the dwarf tapeworm (transmitted by foxes), which can be dangerous to human beings. In many places in eastern Europe, this is the reason mushrooms and berries are not gathered in the wild.

Wednesday, 30 March 2022

CALAMUS (Acorus calamus var. angustatus)

 FAMILY Araceae

SYNONYMS Calamus aromaticus, sweet flag, sweet sedge, sweet root, sweet rush, sweet cane, sweet myrtle, myrtle grass, myrtle sedge, cinnamon sedge. GENERAL DESCRIPTION A reed-like aquatic plant about 1 meter high, with sword-shaped leaves and small greenish-yellow flowers. It grows on the margins of lakes and streams with the long-branched rhizome immersed in the mud. The whole plant is aromatic.

DISTRIBUTION Native to India; the oil is mainly produced in India and Russia and to a lesser extent in Europe (except Spain), Siberia, China, Yugoslavia, and Poland (Polish and Yugoslavian oils have a uniform lasting scent).

OTHER SPECIES Not to be confused with the yellow flag iris which it resembles in appearance; they are botanically unrelated. There are several other varieties of aromatic sedge, mostly in the east, for example, Calamus odoratus is used in India as a medicine and perfume.

HERBAL/FOLK TRADITION The name derives from the Greek calamos meaning ‘reed’. The properties of the herb are mainly due to the aromatic oil, contained largely in the root. It used to be highly esteemed as an aromatic stimulant and tonic for fever (typhoid), nervous complaints, vertigo, headaches, dysentery, etc. It is still current in the British Herbal Pharmacopoeia, for ‘acute and chronic dyspepsia, gastritis, intestinal colic, anorexia, gastric ulcer.’18 In Turkey and especially in India (where it is valued as traditional medicine), it is sold as a candied rhizome for dyspepsia, bronchitis, and coughs. 

ACTIONS Anticonvulsant, antiseptic, bactericidal, carminative, diaphoretic, expectorant, hypotensive, insecticide, spasmolytic, stimulant, stomachic, tonic, vermifuge.

EXTRACTION Essential oil by steam distillation from the rhizomes (and sometimes the leaves). 

CHARACTERISTICS A thick, pale yellow liquid with a strong, warm, woodyspicy fragrance; poor quality oils have a camphoraceous note. It blends well with cananga, cinnamon, labdanum, olibanum, patchouli, cedarwood, amyris, spice and oriental bases.

PRINCIPAL CONSTITUENTS Beta-asarone (amounts vary depending on source: the Indian oil contains up to 80 per cent, the Russian oil a maximum of 6 per cent), also calamene, calamol, calamenene, eugenol and shyobunones. 

SAFETY DATA Oral toxin. The oil of calamus is reported to have carcinogenic properties.

AROMATHERAPY/HOME USE None. ‘Should not be used in therapy, whether internally or externally.’

Tuesday, 1 March 2022

SOME POINTS OF INTEREST IN THE VERNACULAR NAMES OF BIRDS

• Many of the current English common names for birds were original or derivatives of Indian vernacular names, e.g., shama and bulbul.

• Except for Philomachus pugnax, where the male is called Ruff and the female Reeve, all the other common names in English have the same name for both the sexes. This is not so in the case of the Indian vernacular names, where the sexes have different names for quite a few species, especially among ducks, birds of prey, minivets etc., where sexual dimorphism is prominent.

• It appears that some vernacular bird names are onomatopoeic in genesis. Examples are Kaka (Tamil and Malayalam), Kaki (Telugu), Kowwa (Hindi) for crows; Kuku (Kashmiri), Kukku (Lepcha), Phuphu (Kumaon) for the Cuckoo; Tuiya tota (Hindi), Tui suga (Nepal), Tiya or Tiya tota for the Blossomheaded Parakeet and Awak or waak for the Night Heron. Others were based on the physical characters, food habits, diet or habitat the birds frequent. Examples are Naththai kuththi narai (Snail Pecking Stork), Tamil for Openbilled Stork; Peenigala Konga (Corpse Stork), Telugu for the Adjutant Stork; Tena gadda (Telugu) and Ten parandu (Tamil), both of which mean Honey Eagle, for the Honey Buzzard; and Samp mar (Snake Killer) for the Whitebellied Fishing Eagle, which feeds largely on sea snakes.

• The cormorants and gulls have the suffix of Crow added to them in some Indian languages. The cormorants are called water crows and gulls, sea crows. In the first group, it is probably due to their black colour, and in the case of gulls, it is due to its scavenging habit, crow-like raucous calls and maritime habitat

• The name used for harriers in Tamil and Telugu translates to Cat Raptor, and is apt as the faces of the species have the composure and countenance of a cat.

• Telugu names prevalent in Kurnool district of Andhra Pradesh (where one of the ENVIS staff had worked earlier), such as Korra koncha (Demoiselle Crane), burrlakka (quails), ratipoluka (sandgrouse), Samba kaki (Crow Pheasant), Tikka titta (meaning mad bird due to its incessant calls both during the day and night) for Red-wattled Lapwing are unrecorded in literature. We have added these to the list of names given in the table. This shows that a lot more documentation needs to be done on vernacular bird names from the different regions of the Indian subcontinent.

• In Telugu, the flamingo is known as Samudrapu chiluka, meaning sea parrot due to its parrot-like bill.

• The vernacular names for the wagtails sound more comical when translated into English. In Malayalam and Tamil, it reads as Tail Wagger, and in Telugu, Bum Wagger !

• The wagtail group is also called Vannathi kuruvi (Dhobi Bird) in Tamil as they frequent the vicinity of washermen at rivers and lakes.

• The rustic charm in naming of birds is evident in the Sindhi name for the Blackheaded Bunting, Booree, which means deaf. The reason for this name it is said, is that no amount of scaring will chase this species from crop fields.

• The White-throated Fantail Flycatcher has the apt name of Nachan (Dancer) in Marathi, which is befitting as the movements of the bird gives the impression of a delicate dancer.

• Examples of wrong pronunciation of vernacular names by outsiders are the words Chinna (meaning small) which got corrupted to Sinna (a word that does not exist in Tamil) and Kampa (meaning thorn/scrub) into Campa in Ali & Ripley’s Handbook.

• The Little Stint is called Kosu Ullan in Tamil, which translates to Mosquito Wader. Trappers in the Great Vedaranyam Swamp, Tamil Nadu say it is named due to its small size and the large flocks it forms, which from a distance look like swarms of mosquitoes.

• The cute name Rani didao gophita (Little White Water Princess) is used for the Pheasant-tailed Jacana in Cachar district, Assam.

• In Malayalam, the Black Drongo is called as Kakka tampuratti (Queen of Crows) and the Grey Drongo, Kakka tampuran (King of Crows)! Did such names originate from Kerala’s fairy tales? Does the name of Madayan (meaning fool in Tamil) for the Pond Heron also have a fable behind it?

• Artisans’ names are given or prefixed for some bird groups in the vernacular languages, due to certain characteristics of the species. Examples are tacchan kuruvi (Malayalam) and sutaar (Marathi), meaning carpenter or carpenter bird for woodpeckers; sonar (Marathi), meaning goldsmith for orioles; tambat (Marathi), meaning coppersmit for barbets; and taiyalkaran kuruvi (Tamil), darzee (Hindi) and darji (Punjabi), meaning tailor, for tailorbirds.

• It seems fascinating that there are names for nondescript groups of birds as the warblers, e.g., for the Booted Warbler in Malayalam (see Handbook). This only proves that the early Indians did pay attention to nature and birds.  

• In Telugu, the Grey Shrike is known as Kasai pitta, meaning Butcher Bird, which is what the shrike is also called in English.

• The recorded names for all the predominantly yellow coloured orioles in Hindi is Peelak, meaning the ‘the yellow one’. The absence of different names for individual species highlights the need for standardising the vernacular names of birds so that ornithology can develop in the vernacular languages. In the absence of existing names, new names will have to be coined.

• The Telugu name for the Lesser Florican is Nela nemali, meaning Ground Peacock, probably due to the presence of peacock like plumes on the head of cock floricans.

• The names in Telugu for the Bonelli’s Eagle and Booted Hawk-Eagle are Kundeli salawa and Udatala gedda, which roughly translates to Hare Raptor and Squirrel Raptor respectively. The Handbook mentions the prey of the former as large birds and hares and the latter, as small mammals (squirrels and rats) and small birds. This shows that the locals did have a good idea of natural history of these birds. 

Sunday, 2 January 2022

THOTH - Djehuty

Thoth is actually a Greek rendering of the name, which in Egyptian was something in the lines of “Djehuty”. He was present since Predynastic times and was originally an important moon god, a companion of the sun god Re, and identified as the “night sun” or, later, as the “silver Aten”. Only later Thoth assimilated the aspects of knowledge and became the god of scribes and scholars. Thoth was often considered a son of Horus, being born from the forehead of Seth after the latter ate some lettuce with the semen of the former. 

Thoth invented writing and was said to record everything (including the result of the weighing of the heart ceremony, as seen above; Fig. 3B). He also determined the length of each pharaoh’s reign (he was thus called “Lord of Time”), recording it on a palm leaf (Fig. 12A); however, this function was most commonly attributed to his wife (or sometimes daughter) Seshat, who shared most of his aspects anyway. 

Thoth had thus a pristine reputation of integrity and truth. As patron of all areas of knowledge, he also had access to magic and secrets unknown to the other gods. Finally, Thoth was also a messenger of the gods and usually conciliated quarreling deities. This led the Greeks to equate him with their messenger-god, Hermes. The so-called “Hermes Trismegistus” (meaning the “thrice great”) may be a syncretic combination of Hermes and Thoth. (Trismegistus, by the way, is the second form of Junpei Iori’s persona in P3; his starting persona is Hermes.) 

The city housing Thoth’s largest cult center became known to the Greeks as Hermopolis Magna (Khemnu, in Egyptian). To the west of Hermopolis, lies the necropolis of Tuna el-Gebel, where the catacombs known as the “Ibeum” holds hundreds of animal mummies of ibises and baboons, Thoth’s sacred animals. Thoth is most usually depicted as an ibis-headed man (Figs. 12A–B), but can also appear as a full ibis (Fig. 12C); his depiction as a baboon (Fig. 12E) is secondary, but very common. Here is a good place to remark that Egyptian art was very naturalistic when it came to animals (Fig. 12C), representing them in natural poses and lively activities and in a manner that makes possible for us to easily identify the species in question. 

Thoth’s ibis is aptly called “African sacred ibis” (Fig. 12D); its scientific name is Threskiornis aethiopicus (Latham, 1790), meaning the “religious (or worshipping) bird from Ethiopia”. The ibis’ white plumage and long sickled bill probably had lunar symbolic significance. Is his ibis or hybrid form, Thoth isusually shown wearing his own brand of the atef crown (Fig. 12C): it is made of two twisting ram’s horns on its base, from where sprouts three bundles of reeds (each topped by a sun disk), which in turn are flanked by ostrich feathers and uraeus serpents.Unfortunately, the Persona games went for the baboon look (Fig. 12F), but, instead of the atef crown, he has a small solar disk on his head. 

I call it a solar disk because it is golden instead of the lunar silver. The baboons were sacred to the sun god, because these animals sit on their hinds legs at sunrise and raise their hands, which was interpreted as a sign of reverence for the sun. Thoth’s representation (likely based on the yellow baboon, Papio cynocephalus (Linnaeus, 1766); Fig. 12G) was always a sitting baboon with his arms in resting position (Fig. 12E), precisely to differentiate him from the solar baboons. Finally, the book in the official artwork is of a rather modern look; it surely gives a nice effect, though. The wedjat (Eye of Horus) depicted on the book’s covers was sometimes found in amulets of Thoth.


Saturday, 11 December 2021

Ibn al-Nafis

 Firstly describe the pulmonary circulation, coronary circulation, and capillary circulation with true anatomy of the heart which form the basis of the circulatory system. He wrote: “The lungs are composed of parts, one of which is the bronchi, the second the branches of the arteria venosa and the third the branches of the vena arteriosa, all of them connected by loose porous flesh. The blood from the right chamber of the heart must enter the left chamber, but there is no direct pathway between them. 

The thick septum of the heart is not perforated and does not have visible openings as some people thought or invisible pores as Galen thought. The blood from the right chamber must flow through the vena arteriosa (pulmonary artery) to the lungs, spread through its substance, be mingled with air, pass through the arteria venosa (pulmonary vein) to reach the left chamber of the heart Arteries and the heart do not expand and contract at the same time, but rather the one contracts while the other expands” and vice versa. 

He also recognized that the purpose of the pulse is to help disperse the blood from the heart to the rest of the body. He completely rejected the Galenic theory of pulsation after his discovery of the pulmonary circulation. Furthermore, he developed his own Nevisian theory of pulsation after discovering that pulsation is a result of both natural and forced motions, and that the “Forced motion must be the contraction of the arteries caused by the expansion of the heart, and the natural motion must be the expansion of the arteries. 

The primary purpose of the expansion and contraction of the heart is to absorb the cool air and expel the wastes of the spirit and the warm air; however, the ventricle of the heart is wide. Moreover, when it expands it is not possible for it to absorb air until it is full, for that would then ruin the temperament of the spirit, its substance and texture, as well as the temperament of the heart. Thus, the heart is necessarily forced to complete its fill by absorbing the spirit

Thursday, 25 November 2021

A White Great Shark

A great white shark attacks from A Seton and behind, taking its victim by surprise. To do this it has to come up fast and keep its quarry in sight. Its eves must react rapidly to the change in light if its hunt is to be successful. Like all other sharks, the great white relies on its array of senses to locate prey such as seals and sea lions. But its sight is crucial to pinpointing a victim at the surface. Silhouetted against the light just as a human, entering a brightly lit room from the darkness outside, can be briefly dazzled and take 2 few seconds to adjust to the change, so a shark, rising to the surface from the murky depths must cope with a rapid increase in light. It cannot afford to wait for its eves to adjust — a lost second and the prey could be gone.

The secret of this ability lies in the tapetum, a laver of mirror-like plates at the back of the eyeball. It is the tapetum that eerily lights up the cat’s eyes when it is caught in Car headlamps at night. By reflecting light back through the retina, it effectively doubles the amount of light for the eye to use. This is essential for night hunters, like the cat. if they are to see with clarity, especially in the faint moonlight. In the day, though, too much light can be a problem. The cat copes by narrowing its pupil, the gap that Jets in light, to 4 wafer-thin slits, using the muscles in the iris.

The great white shark's tapetum greatly enhances its vision in the murky depths, but it has no iris to protect its eyes when it surfaces rapidly. In order to compensate, it has developed a ‘curtain’ of cells containing pigment. As the shark moves into bright light, these automatically expand over each tapetal plate and then contract as it returns to the depths.

While it is swimming in shallow water, a shark needs to be able to see into the light above it and into the dark below. In this case, the tapetal curtain reacts differently in each half of the eye. The lower half-eye of a killer whale hunting deep in the ocean, a blue shark relies upon reflective plates behind its eyeballs to increase the amount of light striking the retina. of the tapetum, which reflects light from above, is covered to protect the retina. The upper half of the tapetum, which reflects light from below, is exposed to make the most of the light hitting the retina and so give as clear a picture as possible of the murky depths below. 

Wednesday, 13 October 2021

The Guerrilla Warfare

 Those seeking historical insights into counterinsurgency warfare will find Roger Trinquier’s classic modern Warfare: A French View of Counterinsurgency disturbingly current. First published in 1961 and one of the best-selling post-World War II books in France, Trinquier influenced a generation of counterinsurgency scholarship. He succeeded in describing the true face of what current observers also label “modern war.”


Nearly 40 years later, for example, Mark Bowden subtitled his bestsellerBlack Hawk Down, the story of a US Special Forces operation in Somalia gone awry, A Story ofModern War. Despite important differences between Somalia and the colonial independence conflicts Trinquier participated in, ongoing operations in Afghanistan and Iraq reflect many of the nonlinear, unconventional elements of what Trinquier labeled modern war to distinguish between armored battles between nation-states and counterinsurgencies pitting nation-builders against organizations using terrorist tactics.


Trinquier was introduced to counterinsurgency warfare in  Indo-china before being assigned to Algeria in 1957 as a Lieutenant Colonel with the  French  10th  Parachute  Division.  Decades of service conditioned his views. Algeria inspired his writings on modern war, including a penetrating testimony to the central tenet of counterinsurgency: winning the allegiance of the indigenous population. A systematic approach is needed.


Counterinsur-gencies require “an interlocking system of actions political, economic, psychological, the military that aims at the [insurgents’ intended] overthrow of the established authority in a country and its replacement by another regime.” As a military theory, Trinquier’s “modern war” parallels a prominent theme in post-Cold War military thought, one documented by Israeli military historian  Martin  Van  Creveld’s  1991  book, The  Transformation of  War.


Trinquier preceded Van Creveld and other post-Cold War military theorists in arguing that nuclear weapons would lead to a decline in traditional armored warfare and a rise in modern warfare in its many variants: guerrilla warfare, insurgency, terrorism, and subversion.


As do currently military analysts, Trinquierapproached the problem of countering modern warfare by assessing differences between linear clashes of armies and the tactics, goals, methods, and norms of the insurgent or guerrilla. Pitting a traditional combined armed force trained and equipped to defeat similar military organizations against insurgents “reminds one of a pile driver attempting to crush a fly, indefatigably persisting in repeating its efforts.”


In Indochina, for For example, the French “tried to drive the Vietminhinto a classic pitched battle, the only kind knew how to fight, in hope that superiority in material would allow an easy victory.” The only way to avoid similar pitfalls, according to Trinquier is to fight the “specially adapted organization” that is common to almost all subversive, violent movements seeking to overthrow the status quo.


In October 2003 it appeared the UnitedStates was creating its special organization to combat Iraqi insurgents: Task Force 121, a new joint strike unit reportedly composed of American special Forces units and Army Rangers.7Presumably steeped in counterinsurgency warfare, Task Force 121and other units operating against The Iraqi resistance has learned the lessons of past modern wars. They will not simply sweep towns.


This won’t defeat an organized insurgency. Instead, the enemy’s organization must be targeted to de-feat the clandestine organization attempting to impose its will on the Iraqi people. Four elements typically encompass an insurgency: cell networks that maintain secrecy; terror used to foster insecurity among the population and drive them to the movement for protection; multifaceted attempts to cultivate support in the general population, often by undermining the new regime; and attacks against the government.


Only by identifying and destroying the infrastructure of the subversive organization can the fledgling government perseveres. Stated another way, just as the traditional war is not fought with the individual soldier or platoon in mind but rather the state’s capacity and will continue hostilities, modern war seeks to destroy the organization as a whole and not simply its violent arm or peripheral organs.


After comparing the relative resources of the insurgent and government forces, Trinquier concludes “that the guerrilla’s greatest advantages are his perfect knowledge of an area (which he has chosen) and its potential and the support gave him by the inhabitants.” To turn this defeat into a victory, the counterinsurgent must recognize that “this total dependence upon terrain and population is also the guerrilla’s weak point.”


Toward this end, he suggests three simple principles: separate the guerrilla from the population that supports him; occupy the zones that the guerrillas previously operated from, making them dangerous for him and turning the people against the guerrilla movement; and coordinate actions over a wide area and for a long enough time that the guerrilla is denied access to the population centers that could support him.


This requires an extremely capable intelligence infrastructure endowed with human sources and deep cultural knowledge.  Indeed,  intelligence is key. As the Commander of the US Army’s 1st Armored Division in Iraq, Major General Martin Dempsey, observed in November 2003, “Fundamentally, here in Baghdad we do two things: We’re either fighting for intelligence or we’re fighting based on that intelligence.”


Despite unparalleled improvements in military intelligence, the United States does not seem to have the depth and breadth required in human intelligence (humint) and cultural intelligence arenas. Arabic linguists are lacking. Undersecretary of Defense for Intelligence Stephen Cambone, discussing intelligence shortcomings documented in an internal report, might have understated the problem, admitting, “We’re a little short on the humint side; there’s no denying it.”


For Trinquier, intelligence was one of several crucial enablers for de-feating an insurgent. Others included a secure area to operate from, sources in the general population and government, maintaining the initiative, and careful management of propaganda.


A critical step in any counterinsurgency campaign is the creation of a“tight organization” to counter the enemy’s organizational advantages. Created from the bottom up, based on a full appreciation for the tactical situation, a successful counterinsurgency organization must depart from their standard operational approach to warfare.


For example, campaign planning should include a system to account for every citizen, coordination with the political ef-fort to designate a hierarchical network of groups headed by pro-government chiefs, and a system to monitor the activities of guerrilla sympathizers. This entails a census, the issuing of photo-identification cards, and a countrywide intelligence system. The ultimate goal is to separate the fish from the sea, leaving it exposed to the state’s spear.


Thursday, 30 September 2021

SCARLET-WINGED LICHEN MOTH “Hypoprepia miniate”

RECOGNITION Black body mottled with yellow, especially laterally. Long, black, shiny spines arise from irregular blackened patches. On midabdominal segments each seta arises from its own blackened plate, except above spiracle, where two setae share single plate. Larva to 3.5cm. Painted Lichen Moth (Hypoprepia fucosa) smaller, marked with less yellow; middorsal stripe less differentiated (inset).

OCCURRENCE Woodlands and forests from southern Canada to Florida and Texas. One generation with mature caterpillars from May to July northward; two or three generations in Missouri with mature caterpillars nearly year-round.

COMMON FOODPLANTS Lichens and blue-green algae (cyanobacteria) growing

on tree trunks, fallen logs, and rocks.

REMARKS Adults of eastern Hypoprepia vary considerably in different parts of the Southeast, so much so that some lepidopterists feel additional species will eventually be recognized. Hypoprepia and other lithosiine arctiids have anal combs that allow them to eject their fecal pellets distances of 30 or more body lengths. 

The comb, which protrudes from the underside of the anal plate, is hooked under a torus of rectal tissue. Hemolymph (blood) is then forced to the last body segment, where pressure becomes so great that the comb slips and the fecal pellet is ejected with great velocity. “Fecal flicking” foils parasitic and predatory wasps that would use volatiles from the excreta to locate their intended victims.  Hypoprepia caterpillars are cannibalistic on smaller larvae and pupae. The caterpillar overwinters.


Saturday, 11 September 2021

Birds for All Seasons

Watching birds is a delightful activity at any time of the year - provided, of course, that the weather conditions are not too severe! Particular habitats or regions may have more to offer at certain times of the year, however, and a little insight and planning can help decide the potentially interesting areas to visit on a trip at any particular season. Birdwatching is an amazingly popular pastime in Britain. Hence, individuals of all ages are involved, and the degree of eagerness and promise ranges from casual appreciation to nothing short of fanatical pursuit. While many are happy to enjoy the birds that they encounter on their travels, 'twitching' or the pursuit of rarities is an increasingly popular form of modern birdwatching. 

This is fueled by the well-developed twitchers' grapevine, which is centered on various recorded- message bird information telephone lines. While finding or seeing unusual species is exciting, it should not detract from the satisfaction to be found in close, careful observation of common species - for birds of all kinds, be they common or rare, are fascinating and more than repay the time spent observing and studying them. Spring is a wonderful season for the birdwatcher. In woodlands everywhere, it heralds the start of the breeding season, and the songs of the resident species are augmented by those of newly arrived migrants. Dawn is the best time for hearing the widest range of birdsong. 

Migrants and the flow of migrating birds are also clearly seen in spring along Britain's seashores, where headlands and estuaries offer excellent opportunities to see the birds. Summer is a comparatively quiet time of year for the birdwatcher. although not without its highlights. Family parties of songbirds may be found in woods and hedgerows - those migrant species feeding eagerly on ripening berries are storing energy for their forthcoming travels. 

Lakes and reservoirs often attract large numbers of swallows, martins, and swifts which feed on the the abundance of insect life, while estuaries around the coast witness the first gatherings of migrating waders and wildfowl. This is probably the liveliest time to visit seabird colonies on the cliffs: ravenous, fully grown young are being fed continually at this time of the year, so there is plenty of activity. For the birdwatcher with access to the coast, autumn is perhaps the most exciting season: everywhere there are signs of migration and the estuaries begin to fill up with ducks, geese, and waders. 

As the weather deteriorates towards winter, inland birds of many kinds tend to move out to the coast, where the proximity of the sea moderates extremes in the weather. Winter can be an unexpectedly good season for the woodland birdwatcher. The lack of leaves makes observation among trees and bushes relatively easy, and many of the smaller birds band together in roaming flocks, often being joined by winter visitors. Grassy downs, heaths, and marshes can harbor birds of prey at this time of year, and estuaries and wetlands are often outstanding. Birds may appear quite different at changing times of the year and life-cycle. 

Though a puffin is most familiar in its bright adult, summer colors (left and bottom), these illustrations show the changes from four weeks old, at around six weeks, during a first winter, an adult in winter, and an adult in the summertime. No matter in which season, it is always worth keeping a cautious eye on the weather, for abrupt changes or extremes can have a dramatic influence on the numbers and species of birds to be seen. For example, westerly gales in the autumn will initiative migrating seabirds, usually only seen well out to sea, near to the shore, making them easy to observe. 

However, the longer periods of southerly or southeasterly winds in spring can result in admirable conditions for migration, with large numbers of birds arriving overnight; in the autumn these same winds can result in all sorts of interesting and unusual sightings, as birds are blown off their regular migration routes. Sudden and prolonged periods of severe cold in winter can cause large numbers of birds to move towards the warmer south and west of the country, with even more individuals arriving here from Europe.


Monday, 30 August 2021

A Wheel to Watch the Heavens

 High in the Bighorn Mountains of Wyoming, on the stony surface of a windswept plateau, lies the ghostly outline of a spoked wheel eighty-two feet in diameter. Similar rocky circles appear in Saskatchewan, in Arizona, and at some fifty other sites across the North American plains. Some are a few feet in diameter, others are hundreds of times as large. All lie on high ground. 

The wheels are built simply: Thin ridges of stones formation, hub, and usually several spokes. Some have rocky piles, called cairns, in their centers and around the outer circles. The Bighorn medicine wheel - so-called because, to the American Indian, any object with spiritual properties was said to have medicine - is the best preserved and best known.

Historians guess that Plains Indians made this circle as early as the 1100s, but they cannot be certain Not do investigators know the exact purpose of any of the wheels - though clues may lie in their orientation. At the Bigham wheel, for instance, an observer who sights over the cairn in the foreground (above) toward the hub will look into the rising sun on the morning of the summer solstice. A second cairn would mark sunset on the same day. Other rock piles point to the rising and setting of three brilliant stars during seasonal changes.

Such alignments lead some theorists to believe that the medicine wheels like their huge megalithic cousins in Europe, were in fact astronomical observatories. This contention is strengthened by the fact that all such wheels are carefully positioned to offer clear views of the horizon. Furthermore, cairns in some wheels cover postholes that may have held upright timbers, so that the original sites would have looked almost like wooden versions of Stonehenge in England.

But critical questions remain. Why would Plains Indians need to watch the sky? Agricultural tribes might have wanted to keep track of growing seasons, but the nomadic Plains peoples lived by hunting bison. Could they have remembered an earlier age when they planted crops? Or did the solstice mark the turning point of the summer for them, a time to begin counting the days until the start of their southward migration?

Such questions may never be answered. Like the builders of so many of the earth's markings, those who laid out the medicine wheels have vanished, leaving later generations no key to their strange monuments. Desert. Near the small town of Blythe, California, he happened to glance down at the arid landscape. I could hardly believe what 1 saw," he said later. Sprawled across the desert, far from civilization, were the gigantic figures of a man and a long-tailed animal.

Reports of the so-called Blythe Giant continued in the decades to come, prompting scientists and other investigators to take a closer look at the little-known southwestern desert. There, along the arid lower valley of the Colorado River, they have discovered some 275 geoglyphic, obscure symbols, and bizarre, childlike drawings of humans and animals. The Mojave's surface, like that of the Nazca desert, is covered with rocks varnished to a dark sheen by the sun, apparently, the Mojave artists used the same rock-removal technique as the Nazcas to create their enigmatic messages.

Most of these desert markings have been discovered since the 1970s, thanks to the tireless efforts of California archeologist Jay von Werlhor and his collaborator, a local farmer and pilot named Harry Casey. By plane and foot, they have reconnoitered thousands of square miles of the blistering ground that early Spanish explorers called tierra del muerto, "land of the dead." The collaborators' goal is to catalog and describe every desert marking in this vast region. "It's absolutely addictive," Casey has said of his quest. "the more you learn, the more you want to know."

Von Werlhof and his fellow archeologists believe the figures found on the Mojave were created for mystic purposes by the Indians who have inhabited the desert for more than 5,000 years. The date the oldest of the figures to 3000 Bc and the most recent of them to the late eighteenth century AD More primitive configurations, known as rock alignments-twisting lines of boulders set side by side in abstract patterns -may be as much as 10,000 years old.

The investigators offer several interpretations of the weird tableau at Blythe, whose age is variously estimated at between 200 and 1,000 years. According to legends passed down by the Mojave Indians, the manlike form represents an evil giant who terrorized their ancestors. The animal figure, which seems to float upside down over the man's head, is said to be a mountain lion imbued with great power from the Mojave's creator god, it was placed there to weaken the giant's spirit. A less dramatic theory suggests that the giant is a kind of graphic "no trespassing" sign placed by Hopi Indians to keep intruders out of their territory.

Many of the animal figures seem to have retained a spiritual significance to the desert dwellers. A 180-foot-long rattlesnake with basalt eyes, according to Mojave medicine men, has powers of good or evil that can be passed onto humans. A figure near Yuma, Arizona is clearly that of a horse, an animal unknown to the southwestern Indians before the coming of Europeans. 

Archeologists believe that the Indians created the image sometime after Spanish explorers rode through the area in 1540 and that they subsequently used the desert drawing as a ceremonial meeting place. Another figure, not discovered until July 1984, is a startlingly animated rendering of a fisherman who appears to be dancing on the water while aiming a spear at two fish. The tip of the spear is made of hundreds of pieces of glittering quartz and may have been designed to bestow magic powers on real fishermen.

Like their counterparts at Nazca, the Mojave figures apparently served a variety of purposes, and at least some of the drawings may have been astronomical markers. A rock alignment along the Gila River in Ari zona, for example, points precisely to the sunrise at the summer solstice. Another, known as the Black Point Dance Circle, may have been designed as a map of the sun, moon, and Milky Way. Knowledge of the heavens could have given Indians a calendar with which to plan their farming and irrigation-vital information in a difficult environment.

Whatever the purpose of their elaborately drawn geoglyphic, the Indians of the Nazca and Mojave deserts were blessed with ideal natural blackboards upon which to scratch out their designs. The natives of the temperate forests of the American Midwest and South was not so fortunate, but they still managed to mark the landscape with impressive animal figures Like their desert counterparts, these images can best be appreciated from the air. 

Sunday, 30 May 2021

Genus Micrustur

The genus Micrustur is a distinct group of six species of small to large falcons with long tails and short wings that inhabit forests from southern Mexico to Central Argentina. Little information exists on the natural habits of its members; indeed even nidification remains unknown (Brown and Amadon, Eagles, hawks and falcons of the world, I discovered a nest of the Collared Forest Falcon (M. semitorquatus) in a canopied forest (estimated to be 20-40 m high) in southwestern Guarico state, Venezuela. The nest was 12 m from the ground in the cavity of a 38-m tree (determined from a clinometer).

The Cuarico River was 200-300 m east of the nest. I found the nest around IO:00 h on 20 August 1978 and returned four hours later with three companions and tree climbing gear. I discovered one nearly fledged chick inside the nest cavity. I estimated the cavity to be about 0.50 m deep and 0.60 m wide. There were two openings into the hollow, both well sheltered from the rain and on opposite sides of the tree trunk.

One was round, about 20-30 cm in diameter and at the top of the cavity. The hole appeared to be the place where a limb had broken off and since rotted. I first located the nest by hearing the chick calling and then seeing it peering out through this hole; it was probably the entrance used by the adults. The second entrance to the cavity was a vertical slit about 30 x 20 cm. Looking into the cavity from this opening, I could see no evidence of nesting material on the floor of the cavity so presumably this species of falcon, like most others, lays its eggs in a bare scrape.

The floor of the cavity had vines growing across it while the sides of the cavity were white-washed from falcon droppings. Although I could not see any prey remains, the nest smelled heavily of decaying animal matter. When I tried to grab the chick to obtain measurements and photographs it jumped to the round entrance hole and clumsily flew about 30 m to a tree. After climbing down I looked at the chick through 10 x 50 binoculars. The primaries and rectrices were noticeably short and not fully grown. I believe that this chick was the only one because I did not hear any others calling. I first found this pair of falcons on 16 July. Although

I saw an adult, presumably the female (with an obvious brood patch) I failed to find the nest. This bird walked along horizontal tree limbs and called at me. On subsequent visits I saw little of the adults but often heard them. They uttered two calls. The first appeared to be an alarm call aimed at me and sounded like “ho, ho, ho.” The second call sounded like a single long “ho.” At times an adult gave this call and the chick returned it, but at a different pitch. On other occasions the adults gave this call back and forth to one another.

The fact that the falcons nested roughly between June and August suggests that breeding may usually occur in the wet season (April-November in Guarico). Other forest hawks such as the Roadside Hawk (Buteo mugnirostris), Crane Hawk (Gerunospiza caerulestens), and Bicolored Hawk (Accipiter bicolor) also breed in the wet season (pers. observ.). 


 


Wednesday, 18 March 2020

Benefits of Forest to People and Animals

Forest provides multiple benefits to the environment, people, and animals. The list of benefits is as follows

·Forest helps in to cool air temperature by release of water vapor into the air.
·At day time trees generate oxygen and store carbon dioxide, which helps to clean air.
·Forest attracts wildlife and offer food and protection to them.
·Forests offer privacy, reduce light reflection, offer a sound barrier and help guide wind direction and speed.
·Trees offer artistic functions such as creating a background, framing a view, complementing architecture, and so on.
·Well managed forests supply higher quality water with less impurity than water from other resources.
·Some forests raise the total water stream, but this is not true for all forests.
·Forests help in controlling the level of floods.
·Forest provides different kinds of wood which are used for different purposes like making furniture, paper, and pencils and so on.
·Forest helps in giving the direction of the wind and its speed.
·Forest helps in keeping the environment healthy and beautiful.
·Forests also minimize noise pollution.
·Forest helps the scientist to invent new medicine as the forest has a different kind of plants and herb.

All benefits quoted above are purely the outcome of forests and cannot be derived from agriculture. If the cost of these is calculated in terms of money, it will be far above the outcome/benefits of agriculture.

Thursday, 20 February 2020

What was Radiometric dating?

The discovery that natural radiant energy was a much more complex phenomenon than previously thought with various sources dates to the last decade of the nineteenth century. In 1895 Rontgen discovered a new kind of radiation, which he called X-rays, and apparently ‘aroused an amount of interest unprecedented in the history of physical science’ according to J. J. Thomson, Head of the Cavendish Laboratory in Cambridge, reporting to professional colleagues the following year.
We now know that it was indeed a remarkable breakthrough and one that was to bring great benefits and dangers that were not initially appreciated, dangers that were also to arise with the other newly discovered forms of radiation. In 1896 the brilliant French physicist Henri Becquerel discovered that crystals of a uranium salt accidentally placed on top of a wrapped and unexposed glass photographic plate caused the plate to blacken as if it had been exposed to light. Becquerel realized that the crystals were spontaneously emitting some unknown type of energy similar but different to X-rays.
The radiation was solely due to the radium and, unlike light energy, could not be reflected. He also discovered that a lump of radium mineral that he carried around in his pocket burned his skin. But it was the young Polish scientist Marie Curie and her French husband Pierre who made a study of these strange ‘Becquerel rays’. Marie Curie made the all-important discovery that the radiant energy emitted by the uranium salt was an inherent property of the element uranium and together with her husband Pierre named the new phenomenon ‘radioactivity’. In addition, Marie Curie found that the element thorium also emitted similar radiation.
When the Curies examined two naturally occurring uranium ores, pitchblende, and chocolate, they discovered that the radiation emitted was more intense than the uranium or thorium content of their ores, indicating the presence of other radioactive elements. Following the laborious separation processes of fractional crystallization, they managed to distinguish the presence of polonium and the much more radioactive uranium. However, it was a brilliant New Zealander, Ernest Rutherford, working with British chemist Frederick Soddy, who made the breakthroughs that were to lead to the development of radiometric dating.
From experiments on thorium compounds in 1902, Rutherford and Soddy discovered that the activity of a substance is directly proportional to the number of atoms present. From this observation, they formulated a general theory that predicted the rates of radioactive decay and went on to suggest that the gaseous element helium might be a ‘decay’ product of a radioactive element.
At that time, it was not known how many elements were radioactive nor what their decay products might be since radioisotopes had yet to be discovered and there was no instrument available that could measure radioactivity. Nevertheless, Rutherford’s brilliant insights allowed him to suggest that radioactivity might be used as a ‘clock’ to date the formation of some naturally occurring minerals and therefore the rocks that contained them. Rutherford had enormous respect for Kelvin and when addressing a meeting that the great man was attending, referred to Kelvin’s 1862 claim that the Sun could not keep shining unless ‘the great storehouse of creation’ contained some unknown source of energy.
Rutherford and others had now discovered that hidden source – the energy emitted by radioactive elements as they decay within the rocks of the Earth, which is enough to counteract and significantly slow down the rate of cooling. He tried to placate Kelvin by portraying the old man’s prophetic and prescient disclaimer as the hallmark of a very great scientist – ‘that prophetic utterance refers to what we are now considering tonight, radium!’ But Kelvin never really accepted the role that radioactive elements played in the creation of the Solar System, a process that we now understand as stellar nucleosynthesis.
In 1905, Rutherford wrote that ‘if the rate of the production of helium by radium (or other radioactive substance) is known, the age of the mineral can at once be estimated from the observed volume of helium stored in the mineral and the amount of radium present’. On this basis, he determined the very first radiometric date for a fergusonite mineral, which gave a Uranium-Helium age of around 497 million years and one of 500 million years for a uraninite mineral from Glastonbury, Connecticut.
But Rutherford wisely cautioned that these were minimum ages because some of the helium gas would undoubtedly have escaped during the processing of the materials. He suggested that calculations based on lead might be superior: if the production of lead from radium is well established, the percentage of lead in radioactive minerals should be a far more accurate method of deducing the age of a mineral than the calculation based on the volume of helium for the lead formed in a compact mineral has no possibility of escape.
In the same year, an American radiochemist, Bertram Boltwood, went on to provide the first reasonably accurate means of dating the formation of certain minerals within the Earth. Boltwood studied at Yale then in Germany and, on returning to America, worked to improve the analytical techniques of radiochemistry pioneered by his friend Rutherford, who at this time was at McGill University in Montreal. Boltwood made a systematic analysis of radioactive uranium-bearing rocks and noticed that generally both helium and lead were present, with the lead being the stable product of the decay chain from uranium.
Boltwood went on to develop a technique that allowed him, with the aid of a Geiger counter, to measure decay rates and with some chemical apparatus to analyses the remaining lead and uranium concentrations and the ratio of the radioactive isotopes. Initially, he tried out his new method on 10 uranium minerals from rocks whose relative geological age was roughly known, publishing the results in 1907.
These samples ranged in age from 2200 million years for a thoriate (thorium and uranium oxide) from Ceylon (now known as Sri Lanka) to 410 million years for uraninite (uranium oxide) from Glastonbury, Connecticut. The oldest date increased the age of the Earth by an order of magnitude. Although by modern standards these results were not very accurate, for instance, the age of the Glastonbury uraninite has been recalculated to 265 Ma, Boltwood’s technical developments were of enormous importance.
Now the physicists really had to take notice and admit that Kelvin was way off the mark. It began to seem that the geologists had been right all the time to argue that the Earth must be much, much older than 20 million years or so. By 1910, a British geologist, Arthur Holmes, was pursuing a similar approach and embarked on a lifetime’s quest ‘to graduate the geological column with an ever-increasingly accurate time scale’.
He calculated the age of a Norwegian rock, which contained several radioactive minerals, like 370 million years. As the rock was known to have originated within the Devonian geological system, he thus provided the first date for that geological system and period. In retrospect, this was the most accurate of the early radiometric dates and, if Holmes had had the resources to continue his work, radiometric dating would have progressed much faster than it did. Holmes also recalculated some of Boltwood’s published data and arranged them to produce the first geological timescale. He was to improve on this scale continuously for the rest of his professional life.