336 research outputs found
Calcium Absorption in Infants and Small Children: Methods of Determination and Recent Findings
Determining calcium bioavailability is important in establishing dietary calcium requirements. In infants and small children, previously conducted mass balance studies have largely been replaced by stable isotope-based studies. The ability to assess calcium absorption using a relatively short 24-hour urine collection without the need for multiple blood samples or fecal collections is a major advantage to this technique. The results of these studies have demonstrated relatively small differences in calcium absorption efficiency between human milk and currently available cow milk-based infant formulas. In older children with a calcium intake typical of Western diets, calcium absorption is adequate to meet bone mineral accretion requirements
Recommended from our members
Computing camera viewpoints in a robot work-cell
Automatically planning a camera viewpoint for tasks such as inspection in an active robot work-cell is a difficult problem. This paper discusses new methods for computing viewpoints which meet the feature detectability constraints of focus, field-of-view, visibility, and resolution. A theoretical outline of the method is presented, followed by experimental results and a discussion of future work
Low zinc status and absorption exist in infants with jejunostomies or ileostomies which persists after intestinal repair.
There is very little data regarding trace mineral nutrition in infants with small intestinal ostomies. Here we evaluated 14 infants with jejunal or ileal ostomies to measure their zinc absorption and retention and biochemical zinc and copper status. Zinc absorption was measured using a dual-tracer stable isotope technique at two different time points when possible. The first study was conducted when the subject was receiving maximal tolerated feeds enterally while the ostomy remained in place. A second study was performed as soon as feasible after full feeds were achieved after intestinal repair. We found biochemical evidence of deficiencies of both zinc and copper in infants with small intestinal ostomies at both time points. Fractional zinc absorption with an ostomy in place was 10.9% ± 5.3%. After reanastamosis, fractional zinc absorption was 9.4% ± 5.7%. Net zinc balance was negative prior to reanastamosis. In conclusion, our data demonstrate that infants with a jejunostomy or ileostomy are at high risk for zinc and copper deficiency before and after intestinal reanastamosis. Additional supplementation, especially of zinc, should be considered during this time period
Chimera States for Coupled Oscillators
Arrays of identical oscillators can display a remarkable spatiotemporal
pattern in which phase-locked oscillators coexist with drifting ones.
Discovered two years ago, such "chimera states" are believed to be impossible
for locally or globally coupled systems; they are peculiar to the intermediate
case of nonlocal coupling. Here we present an exact solution for this state,
for a ring of phase oscillators coupled by a cosine kernel. We show that the
stable chimera state bifurcates from a spatially modulated drift state, and
dies in a saddle-node bifurcation with an unstable chimera.Comment: 4 pages, 4 figure
A Novel Xenomonitoring Technique Using Mosquito Excreta/Feces for the Detection of Filarial Parasites and Malaria
Given the continued successes of the world’s lymphatic filariasis (LF) elimination programs and the growing successes of many malaria elimination efforts, the necessity of low cost tools and methodologies applicable to long-term disease surveillance is greater than ever before. As many countries reach the end of their LF mass drug administration programs and a growing number of countries realize unprecedented successes in their malaria interven- tion efforts, the need for practical molecular xenomonitoring (MX), capable of providing surveillance for disease recrudescence in settings of decreased parasite prevalence is increasingly clear. Current protocols, however, require testing of mosquitoes in pools of 25 or fewer, making high-throughput examination a challenge. The new method we present here screens the excreta/feces from hundreds of mosquitoes per pool and provides proof- of-concept for a practical alternative to traditional methodologies resulting in significant cost and labor savings
Recommended from our members
Dynamic sensor planning
A method of extending the sensor planning abilities of the MVP (machine vision planning) system to plan viewpoints for monitoring a pre-planned robot task is described. The dynamic sensor planning system presented analyzes geometric models of the environment and of the planned motions of the robot, as well as optical models of the vision sensor. Using a combination of swept volumes and a temporal interval search technique, it computes a series of viewpoints, each of which provides a valid viewpoint for a different interval of the task. By mounting a camera on another manipulator, the viewpoints can be executed at appropriate times during the task so that there is always a robust view suitable for monitoring the task. Experimental results monitoring a simulated robot operation are presented, and directions for future research are discussed
Solvable model for chimera states of coupled oscillators
Networks of identical, symmetrically coupled oscillators can spontaneously
split into synchronized and desynchronized sub-populations. Such chimera states
were discovered in 2002, but are not well understood theoretically. Here we
obtain the first exact results about the stability, dynamics, and bifurcations
of chimera states by analyzing a minimal model consisting of two interacting
populations of oscillators. Along with a completely synchronous state, the
system displays stable chimeras, breathing chimeras, and saddle-node, Hopf and
homoclinic bifurcations of chimeras.Comment: 4 pages, 4 figures. This version corrects a previous error in Figure
3, where the sign of the phase angle psi was inconsistent with Equation 1
Aluminum Effects in Infants and Children
Aluminum has no known biological function; however, it is a contaminant present in most foods and medications. Aluminum is excreted by the renal system, and patients with renal diseases should avoid aluminum-containing medications. Studies demonstrating long-term toxicity from the aluminum content in parenteral nutrition components led the US Food and Drug Administration to implement rules for these solutions. Large-volume ingredients were required to reduce the aluminum concentration, and small-volume components were required to be labeled with the aluminum concentration. Despite these rules, the total aluminum concentration from some components continues to be above the recommended final concentration. The concerns about toxicity from the aluminum present in infant formulas and antiperspirants have not been substantiated but require more research. Aluminum is one of the most effective adjuvants used in vaccines, and a large number of studies have documented minimal adverse effects from this use. Long-term, high-concentration exposure to aluminum has been linked in meta-analyses with the development of Alzheimer disease
- …