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

The Statistical Mechanics of the (2+1)-Dimensional Black Hole

The presence of a horizon breaks the gauge invariance of (2+1)-dimensional general relativity, leading to the appearance of new physical states at the horizon. I show that the entropy of the (2+1)-dimensional black hole can be obtained as the logarithm of the number of these microscopic states.Comment: 12 pages, UCD-94-32 and NI-9401

Census politics in deeply divided societies

Population censuses in societies that are deeply divided along ethnic, religious or linguistic lines can be sensitive affairs – particularly where political settlements seek to maintain peace through the proportional sharing of power between groups. This brief sets out some key findings from a research project investigating the relationship between census politics and the design of political institutions in Bosnia and Herzegovina, Kenya, Lebanon and Northern Ireland

Peripheral vasoconstriction influences thenar oxygen saturation as measured by near-infrared spectroscopy

Purpose: Near-infrared spectroscopy has been used as a noninvasive monitoring tool for tissue oxygen saturation (StO2) in acutely ill patients. This study aimed to investigate whether local vasoconstriction induced by body surface cooling significantly influences thenar StO2 as measured by InSpectra model 650. Methods: Eight healthy individuals (age 26 ± 6 years) participated in the study. Using a cooling blanket, we aimed to cool the entire body surface to induce vasoconstriction in the skin without any changes in central temperature. Thenar StO2 was noninvasively measured during a 3-min vascular occlusion test using InSpectra model 650 with a 15-mm probe. Measurements were analyzed for resting StO2 values, rate of StO2 desaturation (RdecStO2, %/min), and rate of StO2 recovery (RincStO2, %/s) before, during, and after skin cooling. Measurements also included heart rate (HR), mean arterial pressure (MAP), cardiac output (CO), stroke volume (SV), capillary refill time (CRT), forearm-to-fingertip skintemperature gradient (Tskin-diff), perfusion index (PI), and tissue hemoglobin index (THI). Results: In all subjects MAP, CO, SV, and core temperature did not change during the procedure. Skin cooling resulted in a significant decrease in StO2 from 82% (80-87) to 72% (70-77) (P\0.05) and in RincStO2 from 3.0%/s (2.8-3.3) to 1.7%/s (1.1-2.0) (P\0.05). Similar changes in CRT, Tskin-diff, and PI were also observed: from 2.5 s (2.0-3.0) to 8.5 s (7.2-11.0) (P\0.05), from 1.0 (-1.6-1.8) to 3.1 (P\0.05), and from 10.0% (9.1-11.7) to 2.5

Could rebel child soldiers prolong civil wars?

While we know why rebels may recruit children for their cause, our understanding of the consequences of child soldiering by non-state armed groups remains limited. The following research contributes to addressing this by examining how rebels? child recruitment practice affects the duration of internal armed conflicts. We advance the argument that child soldiering increases the strength of rebel organizations vis-�-vis the government. This, in turn, lowers the capability asymmetry between these nonstate actors and the incumbent, allowing the former to sustain in dispute. Ultimately, the duration of armed conflicts is likely to be prolonged. We analyze this relationship with quantitative data on child soldier recruitment by rebel groups in the post-1989 period. The results confirm our main hypothesis: disputes are substantially longer when rebels recruit children. This work has important implications for the study of armed conflicts, conflict duration, and our understanding of child soldiering

500 ml of blood loss does not decrease non-invasive tissue oxygen saturation (StO2) as measured by near infrared spectroscopy - A hypothesis generating pilot study in healthy adult women

BACKGROUND: The goal when resuscitating trauma patients is to achieve adequate tissue perfusion. One parameter of tissue perfusion is tissue oxygen saturation (StO2), as measured by near infrared spectroscopy. Using a commercially available device, we investigated whether clinically relevant blood loss of 500 ml in healthy volunteers can be detected by changes in StO2 after a standardized ischemic event. METHODS: We performed occlusion of the brachial artery for 3 minutes in 20 healthy female blood donors before and after blood donation. StO2 and total oxygenated tissue hemoglobin (O2Hb) were measured continuously at the thenar eminence. 10 healthy volunteers were assessed in the same way, to examine whether repeated vascular occlusion without blood donation exhibits time dependent effects. RESULTS: Blood donation caused a substantial decrease in systolic blood pressure, but did not affect resting StO2 and O2Hb values. No changes were measured in the blood donor group in the reaction to the vascular occlusion test, but in the control group there was an increase in the O2Hb rate of recovery during the reperfusion phase. CONCLUSION: StO2 measured at the thenar eminence seems to be insensitive to blood loss of 500 ml in this setting. Probably blood loss greater than this might lead to detectable changes guiding the treating physician. The exact cut off for detectable changes and the time effect on repeated vascular occlusion tests should be explored further. Until now no such data exist

The negative association between pre-eclampsia and breast cancer risk may depend on the offspring's gender

If the negative association between pre-eclampsia and subsequent breast cancer risk differs by gender, this would strengthen the hypothesis that factors intrinsic to the particular pregnancy may explain the association. The study included 701 006 parous Norwegian women with follow-up for breast cancer through the Cancer Registry of Norway. Breast cancer risk was lower in women with pre-eclampsia/hypertension in their first pregnancy, compared to other women (relative risk, 0.86, 95% CI, 0.78–0.94), after adjustment for age at first birth, maternal birth year, length of gestation, marital status, and parity. The risk reduction was slightly greater if the woman delivered a son as opposed to a daughter (relative risks of 0.79 vs 0.94, P-value for interaction, 0.06), and if pre-eclampsia/hypertension was combined with pre-term delivery, these differences were more pronounced (relative risks, 0.62 vs 1.07, P-value for interaction 0.03). A subanalysis among 176 036 primiparous women showed a substantial risk reduction if the mother delivered a son (relative risk, 0.62, 95% CI, 0.47–0.82), but essentially null if she delivered a daughter (relative risk, 0.92, 95% CI, 0.72–1.18; P-value for interaction, 0.05). These results suggest that the effect of pre-eclampsia/hypertension may be attributed to factors associated with the particular pregnancy rather than an underlying biological trait of the mother. The stronger risk reduction related to having a son suggests a role for sex-dependent hormones in pregnancy

Search for time-dependent B0s - B0s-bar oscillations using a vertex charge dipole technique

We report a search for B0s - B0s-bar oscillations using a sample of 400,000 hadronic Z0 decays collected by the SLD experiment. The analysis takes advantage of the electron beam polarization as well as information from the hemisphere opposite that of the reconstructed B decay to tag the B production flavor. The excellent resolution provided by the pixel CCD vertex detector is exploited to cleanly reconstruct both B and cascade D decay vertices, and tag the B decay flavor from the charge difference between them. We exclude the following values of the B0s - B0s-bar oscillation frequency: Delta m_s < 4.9 ps-1 and 7.9 < Delta m_s < 10.3 ps-1 at the 95% confidence level.Comment: 18 pages, 3 figures, replaced by version accepted for publication in Phys.Rev.D; results differ slightly from first versio

Comparative risk judgements for oral health hazards among Norwegian adults: a cross sectional study

BACKGROUND: This study identified optimistic biases in health and oral health hazards, and explored whether comparative risk judgements for oral health hazards vary systematically with socio-economic characteristics and self-reported risk experience. METHODS: A simple random sample of 1,190 residents born in 1972 was drawn from the population resident in three counties of Norway. A total of 735 adults (51% women) completed postal questionnaires at home. RESULTS: Mean ratings of comparative risk judgements differed significantly (p < 0.001) from the mid point of the scales. T-values ranged from -13.1 and -12.1 for the perceived risk of being divorced and loosing all teeth to -8.2 and -7.8 (p < 0.001) for having gum disease and toothdecay. Multivariate analyses using General Linear Models, GLM, revealed gender differences in comparative risk judgements for gum disease, whereas social position varied systematically with risk judgements for tooth decay, gum disease and air pollution. The odds ratios for being comparatively optimistic with respect to having gum disease were 2.9, 1.9, 1.8 and 1.5 if being satisfied with dentition, having a favourable view of health situation, and having high and low involvement with health enhancing and health detrimental behaviour, respectively. CONCLUSION: Optimism in comparative judgements for health and oral health hazards was evident in young Norwegian adults. When judging their comparative susceptibility for oral health hazards, they consider personal health situation and risk behaviour experience