Various strategies for obtaining artificial hemoproteins: From “hemoabzymes” to “hemozymes”

The design of artificial hemoproteins that could lead to new biocatalysts for selective oxidation reactions of organic compounds presents a huge interest especially in pharmacology, both for a better understanding of the metabolic profile of drugs and for the synthesis of enantiomerically pure molecules that could be involved in the design of drugs.The present results show that the so-called “host-guest strategy” that involves the non-covalent incorporation of anionic water-soluble iron-porphyrins into xylanase A from Streptomyces lividans, a low cost protein, leads to such an artificial hemoprotein that is able to perform the stereoselective oxidation of sulfides.     

From “Overweight” to “About Right”: Evidence of a Generational Shift in Body Weight Norms

In this article, we describe differences in the self‐perception of weight status in the United States between the two most recent National Health and Nutrition Examination Survey (NHANES) periods (1988–1994 and 1999–2004), and test the hypothesis that secular increases in adult mean BMI, adult obesity, and childhood obesity contributed to changes over time in weight perceptions. We find that the probability of self‐classifying as overweight is significantly lower on average in the more recent survey, for both women and men, controlling for objective weight status and other factors. Among women, the decline in the tendency to self‐classify as overweight is concentrated in the 17–35 age range, and is more pronounced among women with normal BMI than those with overweight BMI. Among men, the shift away from feeling overweight is roughly equal across age groups. Overweight men exhibit a sharper decline in feeling overweight than normal weight men. Despite the declines in feeling overweight between surveys, weight misperception did not increase significantly for men and decreased by a sizable margin among women. We interpret the findings as evidence of a generational shift in social norms related to body weight. As a result, people may be less likely to desire weight loss than previously, limiting the effectiveness of public health campaigns aimed at weight reduction. On the other hand, there may be health benefits associated with improved body image.     

Paleodemography: “Not quite dead”

As Kim Hill¹ recently noted in Evolutionary Anthropology, humans are unique among the hominoids with regard to the length of their lives, as well as other elements in the individual life histories. The evolutionary details that modified a basic pongid life history into a hominid one remain obscure, but aspects of recent human demographic history are assailable. Study of the last 10,000 years or so is an important part of ongoing anthropological discourse, for demographic changes may be intimately linked to such major developments as agriculture and urbanization.^2-8 Whether demographic changes are antecedents for or consequences of these major developments is a matter of great contention, but at the least we should attempt to document the nature of human demographic changes in the recent past. Although this documentation can take different forms, the principal sources are archeological information on past settlement patterns and analyses of prehistoric human skeletal material.     

“Infant Mortality in Armenia 1992–2003”: A comment

The purpose of this comment is to counsel caution in some of the conclusions drawn in an otherwise fine article recently published in Economics and Human Biology on infant mortality in Armenia by Hakobyan, Mkrtchyan and Yepiskoposyan. These relate first, to the reliability of estimates and trends in infant mortality estimated from DHS data; second, to the interpretation of what the authors consider to be a ‘low’ infant mortality rate in former communist countries given their level of economic development; and third, to the role of the health care infrastructure in countries of the former Soviet Union in producing these ‘low’ infant mortality levels. This comment argues that trends in infant mortality in Armenia and other CIS countries, although probably declining, are perhaps less certain than the authors allow, that existing evidence does not suggest that they are uniformly low by global standards, or that the health care systems in CIS countries are uniformly effective in reducing infant deaths.     

Evolution of Protein Targeting into “Complex” Plastids: The “Secretory Transport Hypothesis”

Abstract: In algae different types of plastids are known, which vary in pigment content and ultrastructure, providing an opportunity to study their evolutionary origin. One interesting feature is the number of envelope membranes surrounding the plastids. Red algae, green algae and glaucophytes have plastids with two membranes. They are thought to originate from a primary endocytobiosis event, a process in which a prokaryotic cyanobacterium was engulfed by a eukaryotic host cell and transformed into a plastid. Several other algal groups, like euglenophytes and heterokont algae (diatoms, brown algae, etc.), have plastids with three or four surrounding membranes, respectively, probably reflecting the evolution of these organisms by so‐called secondary endocytobiosis, which is the uptake of a eukaryotic alga by a eukaryotic host cell. A prerequisite for the successful establishment of primary or secondary endocytobiosis must be the development of suitable protein targeting machineries to allow the transport of nucleus‐encoded plastid proteins across the various plastid envelope membranes. Here, we discuss the possible evolution of such protein transport systems. We propose that the secretory system of the respective host cell might have been the essential tool to establish protein transport into primary as well as into secondary plastids.