Singlet Pathway to the Ground State of Ultracold Polar Molecules.

Starting from weakly bound Feshbach molecules, we demonstrate a two-photon pathway to the dipolar ground state of bi-alkali molecules that involves only singlet-to-singlet optical transitions. This pathway eliminates the search for a suitable intermediate state with sufficient singlet-triplet mixing and the exploration of its hyperfine structure, as is typical for pathways starting from triplet dominated Feshbach molecules. By selecting a Feshbach state with a stretched singlet hyperfine component and controlling the laser polarizations, we assure coupling to only single hyperfine components of the A^{1}Σ^{+} excited potential and the X^{1}Σ^{+} rovibrational ground state. In this way an ideal three level system is established, even if the hyperfine structure is not resolved. We demonstrate this pathway with ^{6}Li^{40}K molecules, and discuss its application to other important molecular species.

Energization of the Ring Current by Substorms.

The substorm process releases large amounts of energy into the magnetospheric system, although where the energy is transferred to and how it is partitioned remains an open question. In this study, we address whether the substorm process contributes a significant amount of energy to the ring current. The ring current is a highly variable region, and understanding the energization processes provides valuable insight into how substorm-ring current coupling may contribute to the generation of storm conditions and provide a source of energy for wave driving. In order to quantify the energy input into the ring current during the substorm process, we analyze Radiation Belt Storm Probes Ion Composition Experiment and Helium Oxygen Proton Electron ion flux measurements for H+, O+, and He+. The energy content of the ring current is estimated and binned spatially for L and magnetic local time. The results are combined with an independently derived substorm event list to perform a statistical analysis of variations in the ring current energy content with substorm phase. We show that the ring current energy is significantly higher in the expansion phase compared to the growth phase, with the energy enhancement persisting into the substorm recovery phase. The characteristics of the energy enhancement suggest the injection of energized ions from the tail plasma sheet following substorm onset. The local time variations indicate a loss of energetic H+ ions in the afternoon sector, likely due to wave-particle interactions. Overall, we find that the average energy input into the ring current is ∼9% of the previously reported energy released during substorms.

A three-year prospective study of spontaneous eye-blink rate in first-episode schizophrenia: relationship with relapse and neurocognitive function.

OBJECTIVE: To examine the spontaneous blink rate over a 3-year period and its clinical and cognitive correlates among patients with first-episode schizophrenia. METHODS: This study prospectively followed 93 patients with first-episode schizophrenia, schizophreniform and schizoaffective disorders for 3 years. Patients were longitudinally assessed for blink rate, their positive and negative symptoms, and a range of cognitive features including verbal fluency, verbal memory, visual memory, and the Wisconsin Card Sorting Test performance. RESULTS. When compared with a matched control group, there was a significantly higher blink rate at their 3-year follow-up but not at initial presentation. The increase in blink rate over time correlated positively with the number of relapses. It also correlated with logical memory, verbal fluency, categories completed, and perseverative errors in the Wisconsin Card Sorting Test. The increased blink rate also correlated with pre-morbid schizoid and schizotypal traits. All these correlations were statistically significant. CONCLUSION: The change in the blink rate over time may reflect underlying involvement of the dopaminergic system in mediating relapse and cognitive functions.

Magnitude of functional adaptation after intestinal resection.

Intestinal adaptation after resection has been much studied, but rarely examined in an integrative context. Hence we assessed the effects of resection and subsequent adaptation on the quantitative relationship between dietary glucose load and gut capacity to transport glucose. The ratio of capacity to load is termed the "safety factor." Our objectives were to determine 1) the time course of intestinal adaptation after resection, 2) whether adaptation is quantitatively complete, 3) whether survival requires maintaining a safety factor of at least 1.0 for glucose transport, 4) the effect of altered energy demands on adaptation, and 5) the relationship between the amount of tissue removed and the magnitude of functional adaptation. We performed 80% resection of the small intestine on Sprague-Dawley rats and measured small intestinal glucose uptake capacity, dietary glucose load, and gut gross morphology at 1, 5, and 10 wk postsurgery. Nearly all aspects of adaptation were complete by 1 wk postsurgery. After resection, remnant small intestine mass increased by over fivefold within 1 wk, to reach 50-70% of its preresection value. However, mass-specific glucose uptake activity was reduced, so that intestinal regeneration restored uptake capacity to only 33% of control values. Increased energetic demands had only modest effects on intestinal adaptation. Although the safety factor for small intestinal glucose uptake remained <1.0 (i.e., capacity < load) after adaptation to resection, nearly all rats survived. Hindgut fermentation of nonabsorbed nutrients appeared to contribute to that survival, despite inadequate small intestinal capacity. After less massive resection surgeries (25, 50, and 75% resections), the percent increase in glucose uptake capacity increased with the amount of tissue removed.

RF microcoil design for practical NMR of mass-limited samples.

This paper addresses practical issues involved in obtaining high resolution 1H NMR spectra from samples containing less than 10 nmol. Solenoidal microcoils have been constructed to: (a) assess the effects of magnetic susceptibility mismatches at 500 MHz, (b) increase the concentration sensitivity of microcoil probes, (c) incorporate a lock channel for 2D experiments and long 1D acquisitions, and (d) assess the total amount of the sample required (with respect to the coil length) to avoid line broadening due to edge effects. Compared to previously published microcoil results, sample volumes have been increased by a factor of 20 with a concomitant decrease in the required concentration (5-20 mM). Perfluorocarbon susceptibility matching remained effective at 500 MHz, allowing acquisition of high resolution NMR spectra. A lock channel has also been successfully incorporated in microcoil probes. The limits of detection for sucrose with a 10 min acquisition time were found to be 17.8 and 34.1 pmol for the single and double resonance coils, respectively. A sample length of approximately 10 times than that of the coil was required to avoid magnetic susceptibility artifacts.

Impairment of nutrient uptake in a rabbit model of gastroschisis.

Infants with gastroschisis (GS) commonly require total parenteral nutrition and prolonged hospitalization because of intestinal dysfunction resulting from dysmotility and/or malabsorption. To investigate prepartum small intestinal (SI) nutrient absorption in GS, a fetal rabbit model was surgically created on gestational day 24 (term, 31 to 33 days) in 11 time-mated New Zealand White does in each left ovarian-end fetus. Each right ovarian-end fetus served as a control (C) and was manipulated only. All does, 10 of 11 GS fetuses (91%), and 8 of 11 C fetuses (73%) survived to gestational day 30. GS fetuses had significantly reduced total body weights, SI weights, and SI lengths compared with C fetuses. Using the everted mucosal sleeve technique, the uptakes of an amino acid (proline) and a sugar (glucose) were determined. The uptakes of proline per milligram SI, proline per centimeter SI, and glucose per milligram SI were significantly impaired in GS fetuses compared with C fetuses (P < .04 by Student's paired t test). The uptake of glucose per centimeter SI was also reduced in GS fetuses, but not significantly. Uptake capacities (a measure of the entire SI's ability to absorb a given nutrient) were significantly reduced in GS fetuses compared with C fetuses (proline, 2,670 +/- 612 nmol/min/entire SI v 6,842 +/- 399 nmol/min/entire SI, P < .008 by Student's paired t test; glucose, 402 +/- 69 nmol/min/entire SI v 950 +/- 103, P < .008 by Student's paired t test).

Upregulation of nutrient transport in fetal rabbit intestine by transamniotic substrate administration.

Delivery of nutrients to the developing fetal gastrointestinal tract has been advocated as a potential prenatal treatment for intrauterine growth retardation. To examine the effect of intrauterine nutrient administration on the uptake capacity of the intestine, 16 maternal rabbits underwent bilateral ovarian-end transamniotic catheter placement on gestational Day 24. Study fetuses received a galactose solution; the contralateral controls received mannitol, a physiologically inert carbohydrate. Infusions were continued until Day 30 when an everted sleeve technique was used to measure radiolabeled uptake of both galactose and glucose in the proximal, middle, and distal small intestine. Mucosal scrapes were obtained, weighed, and the percentage of weight was calculated. Results were analyzed by ANOVA and Student's t test with P less than 0.05 being considered significant. There were 2 maternal deaths with 11 fetal pairs surviving (79%). There was increased uptake of galactose in the study fetuses compared to controls reaching significance in the middle and distal segments. Similarly, glucose uptake was significantly increased in the proximal and distal segments. Mucosal weight was increased in all regions, reaching significance in the proximal segment. Total intestinal uptake of galactose and glucose was significantly increased in the study fetuses compared to controls. Intraamniotic galactose infusion caused not only upregulation of its own mucosal transport but also that of glucose, along the entire fetal small intestine, achieving statistical significance particularly in distal segments. Fetal implications for transamniotic feeding are under investigation.

Height distributions of U.S. children: associations with race, poverty status and parental size.

The stature of children, relative to that of a reference population, is often used as a measure of the nutritional status of a population. But while undernourished children are often small in stature, all small-statured children cannot be assumed to be undernourished as a wide range of hereditary, socioeconomic and health factors also influence growth processes. The distribution of heights of 3850 "healthy" U.S. children 1-11 years of age who participated in the first National Health and Nutrition Examination Survey, a probability sample of the U.S. population, have been examined in relation to age- and sex-specific reference medians, and in relation to race, family income, and height of their parents. The distribution of heights of black children was shifted to the right (i.e., taller) of that of white children (Index of Dissimilarity = 7.9%). The distribution of heights of children of above poverty level income families was shifted to the right of that of children of below poverty level income families (Index of Dissimilarity = 8.4%). In both races, and with family incomes both above and below the poverty income level, the distribution of heights of children of tall parents was shifted to the right of that of children of short parents (Index of Dissimilarity = 20.25%). We concluded that parental stature, economic conditions and race must be considered in interpreting the growth of children in all societies, and before concluding that nutritional factors are the major determinants of short stature.