Nuclear weapon

 

Nuclear firearm are included in the list of weapons of mass destruction. They are explosive devices based on nuclear reactions. These reactions can be of two types-nuclear fusion or nuclear fission. In the former case, two or more atomic nuclei are combined to form one or more different atomic nuclei. Whereas in later case, the nucleus of an atom splits into two or more smaller, lighter nuclei. In both cases bomb releases a large quantities of energy from relatively small amounts of matter. This energy is far greater in strength as compared to traditional explosive devices. This brings the danger for human race on the earth surface.

The contemporary time is also referred as the nuclear epoch due to worldwide competition to produce more nuclear bombs. Present time nine different countries of the world have the nuclear weapon in different quantities and different types.  It includes USA, Russia, Britain, France, China, India, Pakistan, Israel and North Korea.  Of these countries, first five were the sole owner of the nuclear weapon in the world till the 1970s.  USA firsted tested in 1945 and last one in 1992 and total she had tested 1054 times.  Russia has first tested in 1949,  Britian in 1952.  Russia has tested 715 times and Britain had tested 45 times.  India has started its nuclear weapon program in 1974 under the Prime Ministrer Indira Gandhi then in 1998 under Atalbihari Vajpayee it tested 5 times. North Korea is the latest inclusion in these list of the countries.  It has firsted tested in 2006 and its last test was in 2013.  The Israel is the only country which follows the policy of non-disclose of its nuclear weapon testing and programme. It neither accept the having of nuclear weapon nor denies it.

It is very difficult to say about the real number of nuclear weapon exists in the world. Based on their testing some approximatation can be made. Based on this, it is possible that US has 7,7650, Russia has 8,420,  Britian has 225,  North Korea has 10 and Israel has 80 nuclear weapons. Based on SIPRI (Stockholm International Peace Research Institute) calculation during the starting of last year , 2019, world had approximately 13, 865 nuclear weapons.

So the danger of nuclear weapon is not limited to particular nations but spans the whole human civilizations.  Who will first attach this nuclear weapon?  It is very difficult to say.  But does everyone think like this? Or the western developed nations thinks differently? Most of the developed nation have the general opinion that nuclear weapon in the any third world leader hand could be more dangerous.  In this context,  anthropologist Hugh Gusterson tells in his book- Nuclear ritual (1996) that most of the nuclear weapon scientist thinks that neither America,  Russia or Britian nor any other European coutries will fist use the nuclear weapon.  If the any country that can use it it will be of third world countries. Defence Intelectual,  experts,  politicicians have a opinion that world can live with the nuclear weapon having only in five dhikarik countires can be safein near future.  But the proliferation of thse nuclear weapons to the third world coutnries, especially any muslim country,  will  be disastrous and very dangerious.  . 

Whenever we talked about the nuclear weapon we will remember with the first testing the first case of bombing of the nuclear bomb.  The incident started from the America’s entry into second world war after the ‘Pearl Harbour attack’ and ended with the nuclear bombing on Japan.  Hiroshima and Nagasaki were the two cities which were bombed on 7^th and 9^th of August 1945 by the America’s B-29 bomber fighter planes.   

With the inclusion of America in India’s perspective we remember Gandhijis’s saying. Guha has written about the incident in his book –Gandhi- 1919-1948, the year that changed the world.  Replying for answers regarding  questions on inclusion of America in world war II,  Gandhiji  said that he does not whether America can averted the its inclusion in the war.  But he is of the opnion that it was the only country which can act as mediator for the world war.  But after its inclusion no power had left in the world to safe the humanity from this destruction. 

Though from the 1945 nuclear weapon had never be used till date. But there were several incidents on which humanity save barely from the nuclear attack- Quba conflict in 1962 and Abel Archer danger in 1982. When we feared only with the name of nuclear weapon then what happened to the people who worked day and night in the production of such weapons. What they though aout the war and nuclear destruction?  Does they also think their work as dangerious.  Or rate their work lower than other work?  Based on these questions,  anthropologist Hugh Gusterson has studied the Laurence Liverpool National Laboratory which have designed nutron bomb and warhead of M X missile. with his detailed ethnography, Gusterson revealed about top-secret life and work of nuclear scientist.  He also explored the dark humour, secrecy,  and disciplined emotions in their life and world.  He came out some interesting facts about them. Working in nuclear weapon programe,  these Scientist does not considred as dangeours. Instead,  they consider their work important and respectable.  These scientist come with diverse background.  It considered both liberal,  who are against the Vietnam war and also orthodox,  who are with the Vietnam war.  He explores how their whole life is exited in secrecy.  They cannot share their daily work even to their family members. For your their work security and contract, they cannot take their work at their home.  Even they cannot tell their disturbance at work to anyone.  If they want to move to other sector,  they cannot show their work to their prospective employer.  In another words, they have mortgage their careers to national American defence.     

Then question arises that in these different circumstances, how and why they continue their work.  Or why they sacrifice so much of their careers. Gusterson explores some of the reasons.  In such laboratory using good, scientist can freely explore limitless dimension of science. Majority of weapon scientist do not like the university jobs. At university system one has to content with less salary, regular write and seek for the fund, struggles to the tenure system for their research work.  And these scientist even do not want to work in industry because working in such private industries they have the limit their research work. 

Biozological Malaria

 

The life cycle of the malaria parasite is complex. The process -three phases in the mosquito and two in the human host- has been divided by scientists into nearly a dozen separate steps.  The parasite is transmitted to humans by the sporozoites forms in the saliva of infected female mosquitoes of the genus anopheles.  Soon after entering the human host,  the sporozoites invade liver cells, where during the next 5-15 days they develop into schizonts. 

Each schizonts contains 10,000-30,000 ‘daughter’ parasites  called merozoite, which are released and invade the red blood cells.  Once inside the red blood cells, each merozoite matures into schizonts containing 8-32 new merozoites.  The red blood  cell eventually ruptures and releases the merozoites, which are then free to invade additional red blood cells. The rupturing of red blood cells is associated with fever and signals the clinical onset of malaria. 

Figure 1 the life cycle of the malaria parasite

Some merozoites differentiate into sexual forms, gametocytes, which hare ingested by a mosquito during its next blood meal.  Once in the mosquito,  the sexual forms leave the blood cells, and male and female gametes fuse to forma a zygote.  Over the next 12 to 48 hours, the zygote elongates to form an ookinete.  The ookinete penetrate the wall of the insect’s stomach and becomes an oocyst.  Over the next week or more, depending on the parasite species and ambient temperature, the oocyst enlarges,, forming more than 10,000 sporozoites.  When the oocyst rupture, the sporozoites migrate to the mosquito salivary glands,  from where they may be injected back into the human host, thus completing the cycle. 

Malarial illness may recur months to years after apparently successful treatment. In patients infected with P. vivax and P.  ovale, this phenomenon is known as relapse.  Relapse is caused by dormant liver-stage forms of the parasite that resume their developmental cycle and release merozoites into the bloodstream.  The recurrence of malaria by P.  falciparum and P.  malariae is due to recrudescence, which is caused by surviving blood-stage parasites from an earlier infection.

The mosquito

 

Of the more than 2,500 species know of mosquitoes worldwide, only a sub-groups of 50 to 60 species belonging to the genus Anopheles are capable of transmitting malaria.  Female anopheline require blood meals to reproduce.  Some anopheline species are indiscriminate feeders; others prefer to fed on animals (zoophilic) or human (anthropophagic). 

Anopheline mosquitoes breed in relatively clean water, with certain species having very specific preferences as to their aquatic environment.  Understanding these preferences is crucial for targeting effective malaria control interventions.  For example,  An. stephensi can breed in tin cans and water cisterns, while Anopheles gambiae, the most important malaria vector in Africa south of the Sahara, prefers small, sunlit pools. 

The mosquito undergoes four stages of growth: egg, larva,  pupa and adult ( imago).  Adult females mate once and store the sperm. The female may deposit a total of 200 to 1,000 egg in three or more batches.  Actual egg production is dependent on blood consumption.  After hatching, anopheline larvae lie along the water-air interface, where it is thought that they feed on organisms along the surface film.  Adult mosquitoes develop from the pupil stage within 2 to 4 days.  An adult mosquito will emerge from the egg stage in 7 to 20 days,  depending on the species of mosquito and environmental conditions. 

Female anopheline mosquitoes can survive at least a month under favourable conditions of high humidity and moderate temperatures.  That is sufficient time for them to take a blood meal, for the parasite to develop, and the mosquito to take another blood meal and thus transmit the parasite to second human host. 

Mosquitoes are rarely found more than a few miles from their larva development site. They are readily blown short distance by the wind and have been transported internationally as unintended stowaways on air-planes.  Mosquitoes seek their host in response to a combination of chemical and physical stimuli, including carbon dioxide plumes, certain body odors, warmth, and movement. 

Anopheline mosquitoes feed most frequently at night and occasionally in the evening,  or in heavily shaded or dark areas during the early morning.  During feeding, the mosquito injects a minute amount of salivary fluid into the host to increase blood flow to the area.  Sporozoites are transmitted to the host in the salivary fluid. 

Anopheles mosquitoes are readily distinguished from other genera by their characteristic stance, in which they appear to be standing on their heads (most mosquitoes hold their bodies relatively parallel to the surface on which they are resting).  After feeding, some engorged females seek out cool and humid areas of a house, such as walls and the underside of furniture, while others find dark, secluded spots outdoors near the ground.  Some mosquitoes have modified their resting behaviour so as to avoid surfaces treated with pesticides. 

The life cycle of the parasite is complicated and involves two hosts, human and anopheles mosquitoes.  The disease is transmitted to humans when an infected Anopheles mosquitoes bites a person and injects the malaria parasites (sporozoites) into the blood.  Sporozoites travel trough the blood-stream to the liver, mature, and eventually infect the human red blood cells.  While in red blood cells, the parasites again develop until a mosquito takes a blood meal from an infected human and ingest human red blood cells containing the parasites. Then the parasites reach the Anopheles mosquito’s stomach and eventually invade the mosquito salivary glands. When an Anopheles mosquito bites a human, these sporozoites complete and repeat the complex Plasmodium life cycle. P. ovale and P. vivax  can further complicate the cycle by producing dormant stages (hypnozoites) that may not develop for weeks to years ( see schema of the life cycle of malaria in Chart ).

 

 

 

 

Malaria as a Disease

 

The symptoms characteristic of malaria include flu-like illness with fever, chills, muscle aches, and headache.  Some patients develop nausea, vomiting, cough, and diarrhea. Cycles of chills, fever, and sweating that repeat every one, two, or three days are typical.  There can sometimes be vomiting, diarrhea, coughing, and yellowing (jaundice) of the skin and whites of the eyes due to destruction of red blood cells and liver cells.

People with severe P. falciparum malaria can develop bleeding problems, shock, liver or kidney failure, central nervous system problems, coma and can die from the infection or its complications.  Cerebral malaria (coma, or altered mental status or seizures) can occur with severe P.  falciparaum infection.  It is lethal if not treated quickly; even with treatment, about 15-20% of patients die.

The distinction between infection and disease is particularly important in malaria, since infection with the parasite does not necessarily result in disease.  Many infected people in areas where malaria in endemic are asymptomatic: they may harbor large numbers of parasites yet exhibit no outward signs and symptoms of the disease. However, symptomatic individuals are major contributors to the transmission of malaria parasites.

For reasons not fully understood, the epidemiology of malaria transmission and the severity of the disease vary greatly from region to region, village to village, and even from person to person within a village or town.  Some of this differences are due to the particular species of parasite.

The degree of compliance with an anti-malarial drug regimen, local patterns of drug resistance,  and an individual’s age, genetic makeup, and duration of exposure to infective mosquitoes may also influence the severity of the disease. 

Assuming they survive childhood,  people in areas of endemic malaria often acquire a moderate level of immunity to malaria by being infected repeatedly.  Although they may experience mild symptoms of the disease,  including recurrent fevers, they rarely suffer the more severe and potentially fatal  consequences.  Without repeated exposure, however, this immunity is relatively short-lived, and almost always protects against life-threatening malaria, it does not prevent occasional episodes of fever and chills.

Some population groups have genetic characteristics that render them resistant to certain forms of malaria.  For example, person of African descent who lack the so-called Duffy blood group surface antigens cannot be infected with P. vivax. The heterozygous sickle cell trait, often present in the people of African descent, partially protects against the infection with P. falciparum.  Other hereditary abnormalities such as glucse-6-phosphate dehydrogenase deficiency, are partially protective against malaria.  Those with Sickle cell anemia also have less risks of malaria.

Medical personnel should suspect malaria in anyone with a fever who has recently been in a malaria-endemic region. A definitive diagnosis of malaria infection is made by microscopic examination of stained blood smears for the presence of parasites.  In the early stages of infection and at all stages of infection with P. falciparum, when parasites disappear from the peripheral blood during schizogony, few or no parasites may be present in blood smear;  examination of blood smears taken at frequent intervals may be necessary to establish a diagnosis. A positive blood smear taken from a feverish patient living in an endemic region does not conclusively implicate malaria a the case of illness,  because may asymptomatic individuals have circulating parasites in their blood and the fever may be due to other infections agents. 

Despite being spread over large regions of the world, malaria is a “focal” disease.  That is, because of the complex interactions among the human host, mosquito vector, malaria parasite, and the local environment, malaria affects discrete population groups in different ways. This lack of uniformity is a major reason why it is so difficult to design effective an all-encompassing control strategies. 

 

Malariya and evolution of human

 

Why do mosquitoes bite me and not my friend

How moquitoes evolved to crave human blood

Why mosquito chosen human only

How they got the human blood taste

Anthropology of mosquitoes

Mostoitoes taste for human blood may grow as African cities expand.

 

E. O. Wilson observed: "If all mankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed ten thousand years ago. If insects were to vanish, the environment would collapse into chaos."[13] A Nova segment on the American Public Broadcasting Service framed the relationship with insects in an urban context: "We humans like to think that we run the world. But even in the heart of our great cities, a rival superpower thrives ... These tiny creatures live all around us in vast numbers, though we hardly even notice them. But in many ways, it is they who really run the show.[14

 

Malaria, transmitted by Anopheles mosquito vectors, belongs among the most dangerous diseases in the world, killing half a million people every year. According to the WHO, nearly half of the world´s population is at the risk of malaria. It is widely suspected that malaria could be linked with the decline of city-state populations in ancient Greece and may have contributed to the fall of the Roman Empire during the 5th century AD. Indeed, malaria was so prevalent in Rome that it became known as "Roman fever". However, estimating the historical distribution of malaria and its vectors has proven to be a challenge.