A Review of Dietary Zinc Recommendations

Background. Large discrepancies exist among the dietary zinc recommendations set by expert groups. Objective. To understand the basis for the differences in the dietary zinc recommendations set by the World Health Organization, the U.S. Institute of Medicine, the International Zinc Nutrition Consultative Group, and the European Food Safety Agency. Methods. We compared the sources of the data, the concepts, and methods used by the four expert groups to set the physiological requirements for absorbed zinc, the dietary zinc requirements (termed estimated and/or average requirements), recommended dietary allowances (or recommended nutrient intakes or population reference intakes), and tolerable upper intake levels for selected age, sex, and life-stage groups. Results. All four expert groups used the factorial approach to estimate the physiological requirements for zinc. These are based on the estimates of absorbed zinc required to offset all obligatory zinc losses plus any additional requirements for absorbed zinc for growth, pregnancy, or lactation. However, discrepancies exist in the reference body weights used, studies selected, approaches to estimate endogenous zinc losses, the adjustments applied to derive dietary zinc requirements that take into account zinc bioavailability in the habitual diets, number of dietary zinc recommendations set, and the nomenclature used to describe them. Conclusions. Estimates for the physiological and dietary requirements varied across the four expert groups. The European Food Safety Agency was the only expert group that set dietary zinc recommendations at four different levels of dietary phytate for adults (but not for children) and as yet no tolerable upper intake level for any life-stage group

Wireless Stimulation of Antennal Muscles in Freely Flying Hawkmoths Leads to Flight Path Changes

Insect antennae are sensory organs involved in a variety of behaviors, sensing many different stimulus modalities. As mechanosensors, they are crucial for flight control in the hawkmoth Manduca sexta. One of their roles is to mediate compensatory reflexes of the abdomen in response to rotations of the body in the pitch axis. Abdominal motions, in turn, are a component of the steering mechanism for flying insects. Using a radio controlled, programmable, miniature stimulator, we show that ultra-low-current electrical stimulation of antennal muscles in freely-flying hawkmoths leads to repeatable, transient changes in the animals' pitch angle, as well as less predictable changes in flight speed and flight altitude. We postulate that by deflecting the antennae we indirectly stimulate mechanoreceptors at the base, which drive compensatory reflexes leading to changes in pitch attitude.United States. Defense Advanced Research Projects Agenc

Variations in clinical decision-making between cardiologists and cardiac surgeons; a case for management by multidisciplinary teams?

OBJECTIVE: To assess variations in decisions to revascularise patients with coronary heart disease between general cardiologists, interventional cardiologists and cardiac surgeons DESIGN: Six cases of coronary heart disease were presented at an open meeting in a standard format including clinical details which might influence the decision to revascularise. Clinicians (n = 53) were then asked to vote using an anonymous electronic system for one of 5 treatment options: medical, surgical (CABG), percutaneous coronary intervention (PCI) or initially medical proceeding to revascularisation if symptoms dictated. Each case was then discussed in an open forum following which clinicians were asked to revote. Differences in treatment preference were compared by chi squared test and agreement between groups and between voting rounds compared using Kappa. RESULTS: Surgeons were more likely to choose surgery as a form of treatment (p = 0.034) while interventional cardiologists were more likely to choose PCI (p = 0.056). There were no significant differences between non-interventional and interventional cardiologists (p = 0.13) in their choice of treatment. There was poor agreement between all clinicians in the first round of voting (Kappa 0.26) but this improved to a moderate level of agreement after open discussion for the second vote (Kappa 0.44). The level of agreement among surgeons (0.15) was less than that for cardiologists (0.34) in Round 1, but was similar in Round 2 (0.45 and 0.45 respectively) CONCLUSION: In this case series, there was poor agreement between cardiac clinical specialists in the choice of treatment offered to patients. Open discussion appeared to improve agreement. These results would support the need for decisions to revascularise to be made by a multidisciplinary panel

Female homicide in Rio Grande do Sul, Brazil

This study aimed to assess the female homicide rate due to aggression in Rio Grande do Sul, Brazil, using this as a "proxy" of femicide. This was an ecological study which correlated the female homicide rate due to aggression in Rio Grande do Sul, according to the 35 microregions defined by the Brazilian Institute of Geography and Statistics (IBGE), with socioeconomic and demographic variables access and health indicators. Pearson's correlation test was performed with the selected variables. After this, multiple linear regressions were performed with variables with p < 0.20. The standardized average of female homicide rate due to aggression in the period from 2003 to 2007 was 3.1 obits per 100 thousand. After multiple regression analysis, the final model included male mortality due to aggression (p = 0.016), the percentage of hospital admissions for alcohol (p = 0.005) and the proportion of ill-defined deaths (p = 0.015). The model have an explanatory power of 39% (adjusted r2 = 0.391). The results are consistent with other studies and indicate a strong relationship between structural violence in society and violence against women, in addition to a higher incidence of female deaths in places with high alcohol hospitalization

Phosphorylation Regulates SIRT1 Function

BACKGROUND: SIR2 is an NAD(+)-dependent deacetylase [1]-[3] implicated in the regulation of lifespan in species as diverse as yeast [4], worms [5], and flies [6]. We previously reported that the level of SIRT1, the mammalian homologue of SIR2 [7], [8], is coupled to the level of mitotic activity in cells both in vitro and in vivo[9]. Cells from long-lived mice maintained SIRT1 levels of young mice in tissues that undergo continuous cell replacement by proliferating stem cells. Changes in SIRT1 protein level were not associated with changes in mRNA level, suggesting that SIRT1 could be regulated post-transcriptionally. However, other than a recent report on sumoylation [10] and identification of SIRT1 as a nuclear phospho-protein by mass spectrometry [11], post-translational modifications of this important protein have not been reported. METHODOLOGY/PRINCIPAL FINDINGS: We identified 13 residues in SIRT1 that are phosphorylated in vivo using mass spectrometry. Dephosphorylation by phosphatases in vitro resulted in decreased NAD(+)-dependent deacetylase activity. We identified cyclinB/Cdk1 as a cell cycle-dependent kinase that forms a complex with and phosphorylates SIRT1. Mutation of two residues phosphorylated by Cyclin B/Cdk1 (threonine 530 and serine 540) disturbs normal cell cycle progression and fails to rescue proliferation defects in SIRT1-deficient cells [12], [13]. CONCLUSIONS/SIGNIFICANCE: Pharmacological manipulation of SIRT1 activity is currently being tested as a means of extending lifespan in mammals. Treatment of obese mice with resveratrol, a pharmacological activator of SIRT1, modestly but significantly improved longevity and, perhaps more importantly, offered some protection against the development of type 2 diabetes mellitus and metabolic syndrome [14]-[16]. Understanding the endogenous mechanisms that regulate the level and activity of SIRT1, therefore, has obvious relevance to human health and disease. Our results identify phosphorylation by cell cycle dependent kinases as a major mechanism controlling the level and function of this sirtuin and complement recent reports of factors that inhibit [17], [18] and activate [19] SIRT1 by protein-protein interactions

Cluster Lenses

Clusters of galaxies are the most recently assembled, massive, bound structures in the Universe. As predicted by General Relativity, given their masses, clusters strongly deform space-time in their vicinity. Clusters act as some of the most powerful gravitational lenses in the Universe. Light rays traversing through clusters from distant sources are hence deflected, and the resulting images of these distant objects therefore appear distorted and magnified. Lensing by clusters occurs in two regimes, each with unique observational signatures. The strong lensing regime is characterized by effects readily seen by eye, namely, the production of giant arcs, multiple-images, and arclets. The weak lensing regime is characterized by small deformations in the shapes of background galaxies only detectable statistically. Cluster lenses have been exploited successfully to address several important current questions in cosmology: (i) the study of the lens(es) - understanding cluster mass distributions and issues pertaining to cluster formation and evolution, as well as constraining the nature of dark matter; (ii) the study of the lensed objects - probing the properties of the background lensed galaxy population - which is statistically at higher redshifts and of lower intrinsic luminosity thus enabling the probing of galaxy formation at the earliest times right up to the Dark Ages; and (iii) the study of the geometry of the Universe - as the strength of lensing depends on the ratios of angular diameter distances between the lens, source and observer, lens deflections are sensitive to the value of cosmological parameters and offer a powerful geometric tool to probe Dark Energy. In this review, we present the basics of cluster lensing and provide a current status report of the field.Comment: About 120 pages - Published in Open Access at: http://www.springerlink.com/content/j183018170485723/ . arXiv admin note: text overlap with arXiv:astro-ph/0504478 and arXiv:1003.3674 by other author