Phthalate puzzle

The most common plasticizer, phthalates, are facing stricter regulations due to their omnipresence and possible effects on human health, and environment. But high cost, lack of application range, and unknown long-term effects of non-phthalate alternatives make the scenario puzzling.     

What is a Species? An endless debate

Everybody is familiar with the ubiquitous term ‘species’. But what is a species? Undeniably, this is one of the most complex dilemmas in the history of biology. There is no other concept in biology as elementary yet controversial as the concept of species. In practice, a species is regarded as the fundamental unit of comparison in all biological disciplines like systematics, evolution, ecology, ethology, physiology, and genetics. However, little agreement exists in the scientific community regarding the nature of species, whether it is a real entity or a cultural artifact, its biological significance or how to delineate a species. This article is a review of the seemingly endless debate on the species concept and its implications.     

Nucleosynthesis and energy production in stars: Bethe’s crowning achievement

On the 6th of March this year, the seemingly immortal Prof. Hans Bethe passed away, at the ripe age of ninety eight. His mighty mathematical prowess, coupled with his amazing virtuosity in applying the tools of theoretical physics, helped him make original contributions to an astonishingly large number of topics in theoretical and applied physics. In this age of hyperspecialization and super computers, Bethe steered his path through the myriad problems at the frontiers of physics and kept on calculating numbers on his trusted slide rule. In this article we will discuss one of his great contributions that fetched him utmost satisfaction, in addition to the Nobel Prize. Indranil Mazumdar is reader in nuclear physics at the Tata Institute of Fundamental Research. His primary research activities are in nuclear structure studies, especially experimental studies of the decay of giant dipole resonances from hot rotating nuclei and related instrumentation. His theoretical activities involve investigations of light neutron rich drip line halo nuclei using nuclear three body techniques. He loves cricket, poetry, clouds, rivers and rain.     

Vanishing species: The planet in crisis

Rapid extinction of species is one of the most serious ecological problems faced by humanity today. Species are disappearing at a pace unprecedented in the history of the planet putting the very future of life at risk. The irony is that the root of the crisis is another species, Homo sapiens rather than some physical events that is poised to threaten its own survival. This article gives a brief introduction to the crisis, its consequences and possible mitigation strategies.     

Congenital Lead Poisoning: An Unusual Presentation

Lead poisoning presents a common acquired as well as congenital environmental threat to children’s health today. An unusual case of severe lead poisoning in breast fed male infant is presented here. The objective of the study is to describe a patient who developed clinical lead intoxication with an uncommon source of poisoning. A 6 months old male baby presented with gradual loss of weight, not feeding well and persistent vomiting. Laboratory investigation revealed that he was having anemia (Hb level 5.4 gm/dl), abnormal liver enzymes (including elevated transaminase activity) and high blood lead value (83 μg/dl). RBC morphology showed basophilic stippling with cabot ring, suggestive of a case of lead poisoning. A course of chelation treatment using calcium versenate (EDTACaNa2) was prescribed following which a radical solution for mobilization of lead from his systems was observed.     

Status of Serum Calcium,Vitamin D and Parathyroid Hormone and Hematological Indices Among Lead Exposed Jewelry Workers in Dhaka,Bangladesh

Jewelry utilizes lead either directly or as a base metal. Costume jewelry requires lead before molding and plating the product with valuable metals. Therefore, such ornaments have a great potential to release heavy metals having health hazards. Also, jewelry makers engaged in preparing German silver, an alloy, apply lead in smelting, alloying, rolling and milling silver wires and pieces. The metal is taken up by blood, soft tissues and bone. The biological effects of lead are dependent upon the level and duration of exposure. Lead inhibits three enzymes of heme biosynthesis- δ-amino-levulinic-acid dehydratase (ALAD), coproporphyrin oxidase, and ferrochelatase, impairing heme synthesis and depressing serum level of erythropoietin resulting in decreased hemoglobin synthesis. Lead exposure also affects calcium metabolism and impair the synthesis of Calcitriol. In the present study, jewelry makers from Dhaka, Bangladesh, were shown to have significantly high levels of lead, protein, albumin, and parathormone in their blood, and significantly high amount of zinc-protoporphyrin and δ-amino-levulinic-acid in their urine. The control group, on the other hand showed significantly higher amounts of calcium (both total and ionized form) Vitamin D₃ and non-activated erythrocyte ALAD in their blood, along with hemoglobin. It might be due to inhibition of 1-α-hydroxylase enzyme in renal tubules. Lead causes nephro-toxicity and inhibits 1-α- hydroxylase enzyme leading to decreased calcitriol synthesis resulting in impaired calcium absorption across gastro-intestinal tract and renal tubules. Low Vitamin D₃ and significantly increased Parathyroid hormone (PTH) in study group has been found.     

Affluenza Revisited: Casting Doubt on Cultivation Effects

The researchers use three secondary analyses to explore further the “affluenza” claims linking amount of television viewing with consumerist/materialist values and “affluenza symptoms” such as life dissatisfaction. Those links were generally supported by multiple regression analysis, though at low levels of explanatory power. Heavy news viewing ran in the opposite direction, with heavy TV news viewing correlated with less consumerist values. The authors also found that viewing by streaming on portable devices did not show affluenza correlations. These findings suggest that active audience program selectivity plays a broader role than that envisioned by cultivation theory.