cssi/SciSciGPT-SciSciNet huggingface dataset:
A Computational Model for Gut Looping

In chick embryos, a series of complex invaginations involving the three germ layers (endoderm, ectoderm, and mesoderm) lead to the formation of the primitive gut tube. This process normally occurs during the third day of development, at the end of which the gut appears as an open cylindrical tube (Fig.1A). By the end of the fourth day, the tube is closed except in the middle section, which is connected to the yolk sac (Fig. 1B). The gut at this stage is typically divided into three sections: the foregut, midgut, and hindgut. Now starts the process of gut looping that transforms the initially straight gut tube into the complex intestinal system of the adult chick. The focus of this study is on shape changes that occur between the fourth and fifth days of incubation when the straight gut tube is transformed into an s-shaped one (Fig. 1C). This occurs as the primitive gut tube undergoes rapid elongation, twisting, and rotation causing three distinct bends (the duodenal loop, umbilical loop, and the duodenal-jejunal flexure) to appear simultaneously by the end of the fifth day. Borrowing the term used to describe a similar process in heart development, this initial phase of gut looping is referred to as “s-looping of the gut” in this study.Copyright © 2010 by ASME
Suppression of postprandial lower esophageal sphincter pressure and pancreatic polypeptide by duodenal exclusion.

It has previously been shown that peptone perfusion of an excluded duodenum results in increased lower esophageal sphincter pressure (LESP). The current study was undertaken to determine the effect of duodenal exclusion on the increase in lower esophageal sphincter pressure normally observed postprandially. Six dogs had measurement of fasting and postprandial LESP with simultaneous measurement of gastrin, vasoactive intestinal peptide (VIP), and pancreatic polypeptide (HPP). The animals then underwent duodenal exclusion via a Roux-Y pylorojejunostomy. Experiments were repeated after recovery. All dogs demonstrated the expected marked rise in LESP during control meals (P < 0.001). Duodenal exclusion completely abolished the increase in LESP normally observed postprandially. This difference in response was significant at the level of P < 0.005. The response of gastrin and VIP to feeding were not altered in any way by duodenal exclusion. Pancreatic polypeptide release, however, was markedly attenuated by duodenal exclusion. This difference from the control period was significant at the level of P < 0.05. Duodenal exclusion abolished the response of the LES to feeding and is accompanied by a concomitant decrease in release of pancreatic polypeptide, a hormone with known stimulatory effects on the LES. It appears that the duodenum may make a significant contribution to postprandial increases in LESP.
Food Insecurity Is Associated with Greater Acute Care Utilization among HIV-Infected Homeless and Marginally Housed Individuals in San Francisco

Background Food insecurity, or the uncertain availability of nutritionally adequate, safe foods, has been associated with poor HIV outcomes. There are few data on the extent to which food insecurity impacts patterns of health-care utilization among HIV-infected individuals.
Soybean lecithin fractionation and functionality

Soybean lecithin contains primarity PC, PE, and PI. Fractionation of these phospholipids (PL) is desirable for certain applications. Ethanol was used to fractionate PC and PI, which have different solubilities in this solvent. Various concentrations of ethanol (90, 95, and 100%) and ethanol/gum ratios (0.5, 1.0, 1.5, 2.0, and 2.5) were used. Ethanol concentration significantly influenced the yield of the PC-enriched fraction and the PC and PI fractionation: The highest ethanol concentration resulted in the highest yield of PC fraction, the most PC in the PC fraction, and the most PI in the PI fraction. The ethanol/gum ratio significantly affected the yield of PC-enriched fraction, but did not affect the relative PL composition of the PC-enriched fraction. Ethanol of 90% concentration with a solvent/gum ratio of 3 was used for further large-scale fractionation. Such fractionation resulted in a PC-enriched fraction containing 73% PC, 24% PE, and 3% PI based on the total PL content, whereas the PI fraction contained 26% PC, 35% PE, and 39% PI. Functional properties of these two purified fractions, i.e., surface tension reduction, emulsion stability, and oxidative stability, were investigated. The PI-enriched fraction had a much lower critical micelle concentration than the PC-enriched fraction, which suggests the PI-enriched fraction has a higher surface tension reduction capability. For the emulsion stability test, the PI-enriched fraction performed better than the PC fraction in both water-in-oil and oil-in-water emulsions. An oxidative stability test showed that these PL were very stable to lipid oxidation.
SCNProDB: A database for the identification of soybean cyst nematode proteins

Soybean cyst nematode (Heterodera glycines, SCN) is the most destructive pathogen of soybean around the world. Crop rotation and resistant cultivars are used to mitigate the damage of SCN, but these approaches are not completely successful because of the varied SCN populations. Thus, the limitations of these practices with soybean dictate investigation of other avenues of protection of soybean against SCN, perhaps through genetically engineering of broad resistance to SCN. For better understanding of the consequences of genetic manipulation, elucidation of SCN protein composition at the subunit level is necessary. We have conducted studies to determine the composition of SCN proteins using a proteomics approach in our laboratory using twodimensional polyacrylamide gel electrophoresis (2D-PAGE) to separate SCN proteins and to characterize the proteins further using mass spectrometry. Our analysis resulted in the identification of several hundred proteins. In this investigation, we developed a web based database (SCNProDB) containing protein information obtained from our previous published studies. This database will be useful to scientists who wish to develop SCN resistant soybean varieties through genetic manipulation and breeding efforts. The database is freely accessible from: http://bioinformatics.towson.edu/Soybean_SCN_proteins_2D_Gel_DB/Gel1.aspx
Optimization of planar high-dose-rate implants

Abstract Purpose: Brachytherapy has long been used to deliver localized radiation to the breast and other cancer sites. For interstitial implants, proper source positioning is critical in obtaining satisfactory dose distributions. The present work examines techniques for optimizing source guide placement in high-dose-rate (HDR) biplanar implants, and examines the effects of suboptimal catheter placement. Methods and Materials: Control of individual dwell times in HDR implants allows a high degree of dose uniformity in planes parallel to the implant planes. Biplanar HDR implants can be considered optimized when the dose at the implant center is equal to the dose at the symmetric target boundaries. It is shown that this optimal dose uniformity is achieved when the interplanar separation is related to the target thickness T through the direct proportionality, s = T/√2. To quantify the significance of source positioning, the average dose and a related quantity, equivalent uniform dose (EUD), were calculated inside the treatment volume for two conditions of suboptimal catheter geometry. In one case, the interplanar spacing was varied from 1 cm up to the target thickness T, while a second study examined the effects of off-center placement of the implant planes. Results: Both the average dose and EUD were minimized when the interplanar spacing satisfied the relationship s = T/ √2. EUD, however, was significantly smaller than the average dose, indicating a reduced relative cell killing in the high dose regions near the dwell points. It was also noted that in contrast to the average dose, the EUD is a relatively weak function of catheter misplacement, suggesting that the biological consequences of suboptimal implant geometry may be less significant than is indicated by the increase in average dose. Conclusion: A concise formula can be used to determine the interplanar separation needed for optimal dose uniformity in Manchester-type implants. Deviations from optimal source geometry result in an increase in the average dose inside the treatment volume, but the weaker dependence of the EUD suggests that the surviving fraction of cells may not be not strongly affected by suboptimal source geometry.
Dispersion of the resonant nonlinear optical susceptibility obtained with femtosecond time-domain coherent anti-Stokes Raman scattering

We propose and experimentally demonstrate a method that is capable of resolving both real and imaginary parts of third-order nonlinearity (χ(3)) in the vicinity of Raman resonances. Dispersion of χ(3) can be obtained from a medium probed within microscopic volumes with a spectral resolution of better than 0.10 cm−1.
Systematic Comparison of the Raman Spectra of Metallic and Semiconducting SWNTs

Raman spectra of individual SWNTs were systematically investigated by comparing the behavior of 21 semiconducting and 32 metallic SWNTs. It is found that, compared to semiconducting SWNTs, the RBM of metallic ones is softened, which exhibits chirality dependence. There are significant differences in the line shape of the G-band between semiconducting and metallic SWNTs, which was attributed to electron–phonon coupling previously. However, we found that the differences cannot be explained only by the electron–phonon coupling via the Kohn anomaly mechanism. Curvature effect and other unknown reasons appear to also contribute to the dissimilarities. As for the D-band, the frequency of metallic SWNTs does not show a softening effect when compared with that of semiconducting SWNTs, which is not consistent with theoretical predictions.
A comprehensive model transformation approach to automated model construction and evolution

As models are elevated to first-class artifacts within the software development lifecycle, the task of constructing and evolving large-scale system models becomes a manually intensive effort that can be very time consuming and error prone. To address these problems, this research poster presents a comprehensive approach to model transformation. Within this approach, a high-level aspectual model transformation language is designed to specify tasks of model construction and evolution, and then a model transformation engine is used to execute transformation specifications in an automated manner. Testing and debugging tools at the modeling level are provided to assist in detecting errors in the model transformation.
Linear Systems Arising for Second-Order Mimetic Divergence and Gradient Discretizations

Recent investigations by Castillo and Grone have led to a new method for constructing mimetic discretizations of divergence and gradient operators. Their technique, which employs a matrix formulation to incorporate mimetic constraints, is capable of producing approximations whose order at a grid boundary is equal to that in the grid’s interior. In this paper, we construct a second-order mimetic discretization using Castillo and Grone’s approach and compare it to other second-order discretizations by applying them to an elliptic boundary value problem in one dimension. A detailed perturbation analysis is provided to offer some insight into the two discretizations yielding the best numerical results in the study.
Enkephalin Surges in Dorsal Neostriatum as a Signal to Eat

Summary Compulsive overconsumption of reward characterizes disorders ranging from binge eating to drug addiction. Here, we provide evidence that enkephalin surges in an anteromedial quadrant of dorsal neostriatum contribute to generating intense consumption of palatable food. In ventral striatum, mu opioid circuitry contributes an important component of motivation to consume reward [1–4]. In dorsal neostriatum, mu opioid receptors are concentrated within striosomes that receive inputs from limbic regions of prefrontal cortex [5–13]. We employed advanced opioid microdialysis techniques that allow detection of extracellular enkephalin levels. Endogenous >150% enkephalin surges in anterior dorsomedial neostriatum were triggered as rats began to consume palatable chocolates. In contrast, dynorphin levels remained unchanged. Furthermore, a causal role for mu opioid stimulation in overconsumption was demonstrated by observations that microinjection in the same anterior dorsomedial quadrant of a mu receptor agonist ([D-Ala2, N-MePhe4, Gly-ol]-enkephalin; DAMGO) generated intense >250% increases in intake of palatable sweet food (without altering hedonic impact of sweet tastes). Mapping by "Fos plume" methods confirmed the hyperphagic effect to be anatomically localized to the anteromedial quadrant of the dorsal neostriatum, whereas other quadrants were relatively ineffective. These findings reveal that opioid signals in anteromedial dorsal neostriatum are able to code and cause motivation to consume sensory reward.
Generation and dietary modulation of anti-inflammatory electrophilic omega-3 fatty acid derivatives.

Dietary ω-3 polyunsaturated fatty acids (PUFAs) decrease cardiovascular risk via suppression of inflammation. The generation of electrophilic α,β-unsaturated ketone derivatives of the ω-3 PUFAs docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA) in activated human macrophages is catalyzed by cyclooxygenase-2 (Cox-2). These derivatives are potent pleiotropic anti-inflammatory signaling mediators that act via mechanisms including the activation of Nrf2-dependent phase 2 gene expression and suppression of pro-inflammatory NF-κB-driven gene expression. Herein, the endogenous generation of ω-3 PUFAs electrophilic ketone derivatives and their hydroxy precursors was evaluated in human neutrophils. In addition, their dietary modulation was assessed through a randomized clinical trial. Methods Endogenous generation of electrophilic omega-3 PUFAs and their hydroxy precursors was evaluated by mass spectrometry in neutrophils isolated from healthy subjects, both at baseline and upon stimulation with calcium ionophore. For the clinical trial, participants were healthy adults 30–55 years of age with a reported EPA+DHA consumption of ≤300 mg/day randomly assigned to parallel groups receiving daily oil capsule supplements for a period of 4 months containing either 1.4 g of EPA+DHA (active condition, n = 24) or identical appearing soybean oil (control condition, n = 21). Participants and laboratory technicians remained blinded to treatment assignments. Results 5-lypoxygenase-dependent endogenous generation of 7-oxo-DHA, 7-oxo-DPA and 5-oxo-EPA and their hydroxy precursors is reported in human neutrophils stimulated with calcium ionophore and phorbol 12-myristate 13-acetate (PMA). Dietary EPA+DHA supplementation significantly increased the formation of 7-oxo-DHA and 5-oxo-EPA, with no significant modulation of arachidonic acid (AA) metabolite levels. Conclusions The endogenous detection of these electrophilic ω-3 fatty acid ketone derivatives supports the precept that the benefit of ω-3 PUFA-rich diets can be attributed to the generation of electrophilic oxygenated metabolites that transduce anti-inflammatory actions rather than the suppression of pro-inflammatory AA metabolites. Trial Registration ClinicalTrials.gov NCT00663871
Challenges in Measuring Antibiotic Consumption

The measurement of antibacterial consumption is important for tracking use over time, for assessing correlations between use and antibacterial resistance, and for serving as an outcome measure for antimicrobial stewardship programs. Accurate and consistent measures of use are important for meaningful inter- and intrainstitutional comparisons. The defined daily dose (DDD) and days of therapy methods are commonly used measures in the adult population; however, there is no one ideal measure of consumption that covers the breadth and depth of antibacterial prescribing. The use of the DDD and the prescribed daily dose methods, with further stratification of use by weight and age groups, aids in the evaluation of antimicrobial use in pediatric patients. Increasing availability of computerized pharmacy data should enhance the collection and analysis of data from hospitals.
Inelastic Background and Peak Area Determination in X-Ray Photoelectron Spectroscopy (ESCA)

Analysis of the Au 4f ESCA spectra of thin gold films deposited over a graphite base shows that as the separation from the main photoelectron peak, ΔE, increases the background decreases. Conversely, the effect of a contaminant overlayer on solid gold gives rise to a background which increases as ΔE increases. There is, therefore, a considerable variety of background profiles which can be encountered in real samples, which depends markedly on the element, its concentration, and its distribution in the sample. Over the region of the photoelectron line signal itself, the simple integral description which assumes that the background is proportional to the number of electrons of higher kinetic energy is reasonably valid and is suggested for peak area measurement when a nonlinear profile is needed. Direct integration and curve fitting techniques constitute the two main methods of peak area measurement. Simulated Ni 2p spectra are used to compare the effectiveness of the simple integral and linear background profiles for producing the correct peak areas. Although the simple integral profile shows more consistency and is to be preferred in general, certain fortuitous cancellation effects, particularly with nonmonochromatized spectra, make areas using the linear background fairly accurate in some instances. Curve fitting can overcome many of the problems of direct integration resulting from severe peak overlap. Two types of Gaussian/Lorentzian functions with a suitable exponential tailing function, which has a finite area over reasonable integration limits, are discussed with regard to their use in non-linear least-squares curve fitting methods. Also discussed is the usefulness of composite and difference spectra as simpler methods of determining the relative areas of overlapping peaks.
Release of substance P by granuloma eosinophils in response to secretagogues in murine schistosomiasis mansoni.

Abstract In murine schistosomiasis, granulomas form around parasite ova which lodge in the liver and intestines. The granulomas contain eosinophils which produce substance P. In order to demonstrate substance P release by individual granuloma eosinophils and mechanisms regulating this release, a reverse hemolytic plaque assay was developed. Release of substance P was demonstrated by plaque formation around granuloma eosinophils only when a specific substance P antiserum was used. Few cells released substance P in the basal state. However, eosinophils produced plaques in the presence of calcium ionophore A23187 or histamine. Plaque size and number were dependent upon secretagogue concentration. It is thus concluded that granuloma eosinophils can release substance P in response to both pharmacological and physiological agents.
Poliovirus translation initiation: differential effects of directed and selected mutations in the 5' noncoding region of viral RNAs.

Abstract We have analyzed the translational defects of a number of mutations in the 5′ noncoding region of poliovirus type 1 RNA. These mutations fall into three categories: (1) two mutations which resulted in temperature sensitive (ts) viruses, (2) the second-site mutations responsible for the reversion of the two is viruses, and (3) mutations which were lethal to virus production. RNAs containing either of the is mutations translated in vitro at levels significantly lower than wild-type levels. RNAs containing the respective second-site reversions had corrected these translational defects to levels corresponding to their viral growth potentials. Unlike in vitro translation of wild-type poliovirus RNA, translation of the RNAs which gave rise to is mutant viruses was not stimulated by the addition of an S10 fraction from an uninfected HeLa cell extract to a rabbit reticulocyte lysate (RRL). In vitro translation of the mutant RNAs (corresponding to the is viruses) in a RRL was stimulated by factors present in a ribosomal salt wash (RSW) from a HeLa extract, although the levels of stimulation were only half those seen for wild-type. These results suggest that the stimulatory factors present in the RSW have a decreased affinity for the mutant RNA templates but can, to some extent interact, with such RNAs if provided in high enough concentration. The in vitro translation of RNAs containing either of the lethal mutations was not stimulated by factors present in the S10 or the RSW. Taken together, our data suggest a correlation between the ability of a genetically altered RNA to respond to translation stimulatory factors in vitro and the ability of that mutation to be recovered in infectious virus. In addition, we have identified the in vivo -selected reversion of translational defects for two different is viruses.
BIOGENESIS OF CHLOROPLAST MEMBRANES : I. Plastid Dedifferentiation in a Dark-Grown Algal Mutant (Chlamydomonas reinhardi)

This paper describes the morphology and photosynthetic activity of a mutant of Chlamydomonas reinhardi (y-1) which is unable to synthesize chlorophyll in the dark. When grown heterotrophically in the light, the mutant is indistinguishable from the wild type Chlamydomonas. When grown in the dark, chlorophyll is diluted through cell division and the photosynthetic activity (oxygen evolution, Hill reaction, and photoreduction of NADP) decays at a rate equal to or faster than that of chlorophyll dilution. However, soluble enzymes associated with the photosynthetic process (alkaline FDPase, NADP-linked G-3-P dehydrogenase, RuDP carboxylase), as well as cytochrome f and ferredoxin, continue to be present in relatively high concentrations. The enzymes involved in the synthesis of the characteristic lipids of the chloroplast (including mono- and digalactoside glycerides, phosphatidyl glycerol, and sulfolipid) are still detectable in dark-grown cells. Such cells accumulate large amounts of starch granules in their plastids. On onset of illumination, dark-grown cells synthesize chlorophyll rapidly, utilizing their starch reserve in the process. At the morphological level, it was observed that during growth in the dark the chloroplast lamellar system is gradually disorganized and drastically decreased in extent, while other subchloroplast components are either unaffected (pyrenoid and its tubular system, matrix) or much less affected (eyespot, ribosomes). It is concluded that the dark-grown mutant possesses a partially differentiated plastid and the enzymic apparatus necessary for the synthesis of the chloroplast membranes (discs). The advantage provided by such a system for the study of the biogenesis of the chloroplast photosynthetic membranes is discussed.
The behavior of amidohydrolases and l-glutamate in synchronized populations of Blastocladiella emersonii

Abstract The activities of l -glutamine amidohydrolase, l -asparagine amidohydrolase, and an apparently new enzyme, d -glutamine amidohydrolase, were detected in extracts of the aquatic Phycomycete, Blastocladiella emersonii. The d -glutamine amidohydrolase was very unstable in frozen cells, as much as 60 per cent being lost in 4 days and essentially all of it in 2 weeks, while only 20 per cent of the l -glutamine amidohydrolase was denatured during the latter time. l -Asparagine amidohydrolase was stable under these conditions. The total activity per cell of the d -amidohydrolase remained more or less stationary during ontogeny, but both of the l -amidohydrolases increased many fold to maximum levels at 98 per cent of the cell's generation time, and then decreased again just before sporogenesis. During this last stage in cell development, glutamic acid-14C was rapidly consumed. The 14C derived therefrom was incorporated extensively into protein, but very little of it equilibrated with the cell's water-soluble, free, amino acid pool and various other cell components. The relationship between sporogenesis and certain aspects of nitrogen metabolism in B. emersonii was discussed in the light of these results.
Recent advances in single-asperity nanotribology

As the size of electronic and mechanical devices shrinks to the nanometre regime, performance begins to be dominated by surface forces. For example, friction, wear and adhesion are known to be central challenges in the design of reliable micro- and nano-electromechanical systems (MEMS/NEMS). Because of the complexity of the physical and chemical mechanisms underlying atomic-level tribology, it is still not possible to accurately and reliably predict the response when two surfaces come into contact at the nanoscale. Fundamental scientific studies are the means by which these insights may be gained. We review recent advances in the experimental, theoretical and computational studies of nanotribology. In particular, we focus on the latest developments in atomic force microscopy and molecular dynamics simulations and their application to the study of single-asperity contact.
Overview of Child Development Accounts in developing countries

Abstract Child Development Accounts (CDAs) as a matter of policy have existed for some time, though predominantly in developed countries. While there are at least a few government social programs with CDA components in the developing world, such policies have yet to gain significant traction. This paper finds that despite this lack of policy movement, CDAs do exist in developing countries in a variety of forms and delivered by a diverse group of institutions. Government-linked institutions (such as savings and post banks); non-governmental institutions (such as credit unions and NGOs); and commercial financial institutions are all innovating in CDA design and delivery. This paper offers a review of how CDAs exist in developing countries, including the types of institutions offering CDAs, and design features and delivery mechanisms common among such accounts. The paper concludes with implications of this analysis for policymakers and researchers.
Fluctuation in the level of pluvial Lake Lahontan during the last 40,000 years

Samples of algal tufa, gastropods and calcite-cemented sand were collected from the Walker and Pyramid Lake areas of the Lahontan Basin, Nevada. X-ray diffraction petrographic and radiocarbon analyses show that massive forms of tufa such as the dendritic variety contain secondary carbon-bearing material and therefore yield unreliable radiocarbon dates. Dense coating of tufa (lithoid), however, gave radiocarbon ages in agreement with dates on coexisting aragonite gastropods. Radiocarbon data from the study were combined with previously dated noncarbonate materials [Born, S. M. (1972). “Lake Quaternary History, Deltaic Sedimentation, and Mudlump Formation at Pyramid Lake, Nevada”, Center for Water Resources, Desert Research Inst., Reno, Nevada] to give an internally consistent record of lake level fluctuations for the past 40,000 years. The main features of the Lahontan chronology are (1) extreme high stands (1330 m above sea level) 13,500 to 11,000 and 25,000 to 22,000 B.P., (2) a moderate high stand (1260 m above sea level) 20,000 to 15,000 B.P., (3) a low stand of unknown elevation 40,000 to 25,000 B.P., (4) an extremely low stand 9000 to 5000 B.P., and (5) an overall increase in the size of Walker and Pyramid Lakes during the past 5000 years, until the late 19th century. Pore fluid data indicate that Walker Lake desiccated sometime during the period 9050 to 6400 B.P. Salts deposited as a result of this dessication are still undergoing dissolution causing a flux of chloride, carbon, and other solute species from the sediments to the overlying lake water. Pore fluid data obtained from Pyramid Lake sediments do not indicate the presence of a concentrated brine at depth. This suggests that Pyramid Lake did not dry completely during this period although it may have been severely reduced in size. There has been considerable disagreement regarding the occurrence of extreme arid conditions (altithermal period) since 10,000 B.P. [Mehringer, P. J. (1977). “Models and Great Basin Prehistory”. Desert Research Inst. Pub, Reno, Nevada]. The data of this study suggest that such a climatic regime did occur in the western Great Basin during the period 9000 to 5000 B.P.
User services in the TDRS II era

The next generation Tracking and Data Relay Satellite System (TDRS II) will provide a new level of telemetry, tracking and command services to user spacecraft. In addition to the S-band and Ku-band services, which have made the Space Network concept a reality, a new multifrequency dual-polarization high data rate Ka-band service will also be provided. The S-band multiple-access system will have a larger number of phased array elements, on-board beam forming, and a receive capability equivalent to a single-access antenna. A multifunctional intersatellite link, capable of relaying between TDRS IIs and providing an additional single-access service, is also planned. Enhancements, which include an improved location capability for both the TDRS II and user satellite, a navigation beacon, and a real-time emergency command capability will also be part of the TDRS II. The TDRS II will be three-axis stabilized sufficiently to provide these services to users either on the ground, in low earth orbit, or out to geosynchronous orbit.
Newcastle Disease: Response to Formalized Vaccine

Abstract NEWCASTLE disease has been a serious problem among the Delaware broiler producers since 1946. The literature dealing with the various aspects of this disease is becoming voluminous and a review of it is beyond the scope of this paper. Approximately 95 percent of the chickens started in this area are vaccinated at least once with some type of Newcastle vaccine. As a general rule, if the vaccination is done too early the immunity is of short duration, and if the vaccination is withheld for three or more weeks, natural outbreaks may decimate the flocks before immunity can be produced. The three types of vaccine in common usage are: intranasal, wing-web and formalized (formalin inactivated); all three fulfill the requirements of the U.S.D.A., Bureau of Animal Industry, when the vaccination is performed on healthy chicks of three to five weeks of age. The results in the field are not always satisfactory, …
Relationship between H+, anion, and monovalent cation movements and Ca2+ transport in sarcoplasmic reticulum: Further proof of a cation exchange mechanism for the Ca2+-Mg2+-ATPase pump

Abstract Two spectroscopic probes of free internal Ca 2+ were used to determine the influence of H + and anion permeation on the active transport of Ca 2+ by skeletal sarcoplasmic reticulum. The studies were carried out on a well-characterized Ca 2+ -Mg 2+ -ATPase-rich sarcoplasmic reticulum fraction. Studies of D. McKinley and G. Meissner (1977, FEBS Lett. , 82 , 47–50) show that this fraction consists of two populations of vesicles: type I which has an electrically active monovalent cation (M + ) permeability and type II which lacks it. The present study distinguishes between electrically active (charge-carrying) and electrically silent (e.g., countertransport) mechanisms of ion permeation in the two vesicles and shows how the active transport of Ca 2+ is influenced by these permeabilities. The major results are as follows: (1) Both type I and II vesicles have an electrically active H + permeability. (2) Type I vesicles have electrically active anion (A − ) permeabilities; type II vesicles do not. (3) At low concentrations of nonpenetrating buffers, ion imbalances across the membrane can create pH imbalances. This is due to the coupling of M + and A − movements with H + movements. Following a jump in KCl concentration internal acidification is observed in type I vesicles while internal alkalinization is observed in type II vesicles. These pH gradients are dissipated on a time scale of seconds and tens of minutes for type I and II vesicles, respectively. (4) Tris(hydroxymethyl)aminomethane (Tris) was shown to be effective in dissipating pH gradients in type II vesicles. A model is proposed whereby HCl is equilibrated across the membrane by a Tris-catalyzed transport cycle involving transport of an ion pair between Tris-H + and Cl − and return of the unprotonated form of the buffer. (5) The permeabilities of several physiological and nonphysiological anions were determined for type I and II vesicles. Electrically active permeability was demonstrated for Cl − and phosphate in type I vesicles. Type II vesicles lacked electrically active mechanisms for these two anions. Evidence is given for slow Cl − OH − exchange and for rapid Cl − HCO 3 − exchange in type II vesicles. Electrically silent phosphate influx probably occurs by H 2 PO 4 − OH − exchange. (6) Under normal conditions the Ca 2+ uptake of type II vesicles is masked. It can be unmasked by addition of nigericin in the presence of Tris. The combination of ionophore and penetrating buffer render the type II vesicles KCl permeable, allowing the replenishment of internal K + during active transport. The results are analyzed and shown to be in agreement with the Ca 2+ -Mg 2+ -ATPase pump acting as a Ca 2+ K + exchanger. The results are shown to be in disagreement with electrogenic models of pump function.
Coronary sinus versus aortic root perfusion with blood cardioplegia in elective myocardial revascularization

The role of retrograde coronary sinus cardioplegia in patients undergoing elective coronary artery bypass grafting has not been fully defined. Forty patients undergoing coronary artery bypass grafting received either aortic root (20 patients) or coronary sinus (20 patients) cold potassium blood cardioplegia. The patients were similar with respect to age, ventricular function, severity of coronary artery disease, cross-clamp time, completeness of revascularization, frequency of internal mammary artery grafting, and mean infusate volume and temperature. The time required to deliver the initial dose of cardioplegic solution and the time to achieve arrest were prolonged in the coronary sinus group (p less than 0.001 and p less than 0.02, respectively). There were no differences between the two groups postoperatively with regard to enzymatic indices, hemodynamic measurement, or clinical outcome. Right ventricular function was preserved equally in both groups. We conclude that coronary sinus cardioplegia is a safe alternative to aortic root perfusion, but offers no advantage in elective myocardial revascularization.
Acute lung injury and acute respiratory distress syndrome: mechanisms and potential new therapies

Scientists and clinicians have been searching for effective pharmacologic therapies for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) for several decades, with disappointing results. However, in the past two years important advances have been made in understanding the pathogenic mechanisms of these serious clinical problems, and these may provide targets for pharmacologic intervention. Potential therapeutic goals include modulation of intra-alveolar coagulation and fibrinolysis, inhibition of neutrophil function, augmentation of alveolar fluid clearance, and prevention of the late fibrotic stage of ALI and ARDS.
Evaluation of an instructions and modeling procedure for training behavioral assessment interviewing.

Abstract Ten undergraduate psychology majors served as participants in two experiments training behavioral assessment interviewing skills. In the first study four participants received training with instructions and audio and written modeling in a multiple baseline across participants design. All participants increased interviewing performance substantially with training. The second study was conducted to evaluate the written instructional material alone. After baseline interviews all six remaining participants recieved training with instructions in a multiple baseline across participants fashion. For four participants who did not increase interview performance to 90% correct with instructions, the modeling component was added as a third phase. By the end of a subsequent feedback phase all participants increased their performance to 90% or better. Social validation measures of participants' interviewing performance were then added to evaluate process-related variables in the interview.
Collaboratories as a new form of scientific organization

Science is an inherently collaborative enterprise and this trend has accelerated over the past few decades. In particular, the Internet creates new possibilities for the organization of joint scientific work, specifically among geographically separated collaborators. A notable instance of Internet-mediated science is the collaboratory, or a laboratory without walls, where scientists are connected to each other, to instruments, and to data independent of time and location. This paper explores past and current collaboratory efforts to identify both characteristics that define a collaboratory and factors of collaboratory use that predict scientific success and failure. The paper concludes with an assessment of directions for future collaboratory development.
Critique of Venkatagiri's Hypothesis (2004): A Response to Onslow

In this rebuttal, I show that Onslow falls short both in logic and on facts in his critique of a model of stuttering I proposed.
Constipation in early childhood: patient characteristics, treatment, and longterm follow up.

Little is known about chronic constipation in infants, toddlers, and preschool children and longterm outcome after treatment. The symptoms of 174 children or = 3 bowel movements per week, while not receiving treatment. The recovery rate of children 2 to 4 years of age. Thirty three children (37%) had not recovered. Constipation recurred as soon as laxatives were discontinued in 31 (94%) of them. Laxatives were still used by 33% of the children who had not recovered, 39% had < 3 bowel movements per week, 48% had faecal soiling, 45% had stool withholding, 27% complained of abdominal pain, 73% passed large stools, and 45% still on occasions clogged the toilet with their large stools. Symptoms of chronic constipation persisted in one third of our patients, 3-12 years after initial evaluation and treatment. Children who had not recovered deserve continued follow up, to reinforce and adjust treatment and to prevent faecal soiling.
Clinical application of radionuclide quantitation of left to right cardiac shunts in children

Abstract The results of 341 radionuclide studies, using the method of Maltz and Treves to quantify left to right shunts, were reviewed to evaluate Its clinical usefulness in routine practice. In 245 children in whom a shunt was suspected, 140 were shown to have shunts at cardiac catheterlzatlon, the pulmonary to systemic blood flow ratio ( Q p Q s ) being greater than 1.15 in 121. In 92 of 105 normal children, the ratio was less than 1.05. Nineteen children with a shunt had a ratio in the borderline range of 1.05 to 1.15 as did 13 normal children. Only one normal child had a Q p Q s ratio greater than 1.10 whereas seven children with a shunt had a ratio of less than 1.10, including one with a ratio of less than 1.05. A highly significant correlation (r = 0.71) existed between the shunt sizes estimated with the radionuclide method and with oximetry. However, in 10 of these patients a small shunt shown with the radionuclide method was not detected with oximetry but observed on indocyanine green dye curves. In 41 children, therefore, shunt size measured with the radionuclide method, oximetry and indocyanine green dye curves was compared. The correlation of shunt size was comparable with the three techniques. The radionuclide estimation is therefore considered to be more sensitive than oximetry in the detection of small shunts. The procedure was also valuable in 96 children studied after cardiac surgery; a Q p Q s value greater than 1.15 was present in 17 children, 12 of whom have to date been shown to have a residual shunt.
EXTRAPOLATION OF THE PHENOMENOLOGICAL NUCLEAR EQUATION OF STATE TO HIGH DENSITIES

We propose a modification of the phenomenological Skyrme interaction in order to obtain a nuclear equation of state fitted to the binding energy, saturation density, and incompressibility of nuclear matter and which remains causal at higher densities. The properties of this and other equations of state at transnuclear densities are compared and the implications for stellar collapse and cold neutron structure are briefly discussed.
Racial differences in parathyroid hormone levels in patients with secondary hyperparathyroidism.

AIM African-Americans (AA) with normal renal function have higher parathyroid hormone (PTH) levels than Caucasians (C). This difference was also noted in cross-sectional studies of patients on dialysis. In this study, we evaluated patients with end-stage renal disease who have just began dialysis and who were not receiving any vitamin D therapy. METHODS A total of 363 patients were recruited (C: 260; AA: 103). All patients had serum calcium, phosphorus, alkaline phosphatase and intact PTH (iPTH) levels measured within 3 months of initiating dialysis. RESULTS Serum PTH levels were significantly higher in AA vs. C (383 +/- 33 vs. 246 +/- 19, p < 0.001). This difference was present despite similar calcium, phosphorus and alkaline phosphatase levels between the 2 groups and regardless of gender or diabetes status. However, PTH levels in patients younger than 47 years of age were similar in both groups. CONCLUSION PTH levels in ESRD patients over 47 years of age are higher in AA compared to C. The difference is, in part, due to an age-dependent reduction in PTH seen only in C. Further studies are needed to understand the mechanisms of these racial differences and to verify whether they mirror similar alterations at the level of the end-organ tissue.
Inactivation of yeast alcohol dehydrogenase by N-alkylmaleimides.

Abstract Seven N-alkylmaleamic acids were synthesized and converted through heating to the corresponding N-alkylmaleimides. Alkylmaleimides of varying chainlength were shown to effectively inactivate yeast alcohol dehydrogenase at pH 7.0. The effect of pH on the rate of hydrolysis of N-ethylmaleimide was studied in the pH range from 8.6 to 9.4 where specific base catalysis of the reaction was observed. Second-order rate constants for maleimide inactivation of yeast alcohol dehydrogenase were shown to increase with increasing chainlength of the alkyl substituents of the maleimide derivatives. A chainlength effect was not observed in the reaction of N-ethylmaleimide and N-heptylmaleimide with cysteine and glutathione. Yeast glucose 6-phosphate dehydrogenase, which is less sensitive to maleimide inactivation than is yeast alcohol dehydrogenase, was inactivated by both N-ethyl and N-heptylmaleimide at rates indicating no appreciable chainlength effect.
A hybrid online and offline approach to market measurement studies

This paper presents a case study of how GfK NOP is moving one of the UK's major market measurement studies online. In this case study we share our learning and illustrate, with empirical data, the ...
Role of p21 in Apoptosis and Senescence of Human Colon Cancer Cells Treated with Camptothecin

Treatment of cells with the anti-cancer drug camptothecin (CPT) induces topoisomerase I (Top1)-mediated DNA damage, which in turn affects cell proliferation and survival. In this report, we demonstrate that treatment of the wild-type HCT116 (wt HCT116) human colon cancer cell line and the isogenic p53(-/-) HCT116 and p21(-/-) HCT116 cell lines with a high concentration (250 nm) of CPT resulted in apoptosis, indicating that apoptosis occurred by a p53- and p21-independent mechanism. In contrast, treatment with a low concentration (20 nm) of CPT induced cell cycle arrest and senescence of the wt HCT116 cells, but apoptosis of the p53(-/-) HCT116 and p21(-/-) HCT116 cells. Further investigations indicated that p53-dependent expression of p21 blocked apoptosis of wt HCT116 cells treated with 20 nm, but not 250 nm CPT. Interestingly, blocking of the apoptotic pathway, by Z-VAD-FMK, in p21(-/-) HCT116 cells following treatment with 20 nm CPT did not permit the cells to develop properties of senescence. These observations demonstrated that p21 was required for senescence development of HCT116 cells following treatment with low concentrations of CPT.
Enhanced oxidative desulfurization of model fuels using a film-shear reactor

Abstract A film-shear reactor was used to enhance the oxidative desulfurization of thiophenes in fuels. With selected conditions, one pass of a model fuel through the film-shear reactor provided up to 55% removal of benzothiophene in only seconds at temperatures as low as 10 °C. Recirculation experiments showed that, if the flow rate and all other experimental parameters were held constant, the extent of thiophene removal increased as the residence time increased. Experiments using various concentrations of hydrogen peroxide and different fuel:oxidant ratios showed that, above a minimum amount, an increase in oxidant concentration did not lead to increased thiophene removal.
Microelectrode measurement of oxygen tensions in collagen-hepatocyte gels

Microelectrodes have been used for the measurement of oxygen tension in various biological systems.(Silver, 1987) Although not previously reported, microelectrodes allow the direct measurement of oxygen tension profiles within collagen gels containing entrapped hepatocytes (collagcn-hepatocyte gels). These oxygen tension profiles, along with hepatocyte oxygen consumption data, allowed the estimation of a diffusion coefficient for oxygen in collagen-hepatocyte gels, Dg = 2.99 × 10−5 cm2/s.
Implementation of an acute care surgery service at an academic trauma center.

Abstract Background The establishment of acute care surgery is rapidly becoming a solution to meet emergency surgical needs. Challenges include competition for emergency surgery opportunities and the ability to economically sustain a practice. Methods Clinical activity was measured by reviewing the institutional and practice plan databases. Work relative value units and practice plan collection rates defined clinical activity and revenue. Results Operative procedures and intensive care unit activity accounted for 52% and 36% of activity, respectively. Although procedures on the digestive tract accounted for half of the operative activity, significant activity was observed in nearly all other systems. Overall clinical productivity remained constant but did demonstrate a 25% increase in operative work relative value units. Current billing activity supports 4.0 clinical full-time equivalents, but estimated collections would cover Conclusions The authors describe the implementation of an acute care surgery service that combines trauma, emergency general surgery, and surgical critical care in an established academic surgery department. Developing a sustainable economic model must include income sources other than patient service revenue.
Shell Opening by Crabs of the Genus Calappa

Oxystomatous crabs of the subfamily Calappinae, particularly the genus Calappa, possess a large tooth on the dactyl and a pair of protuberances on the propodus of the right cheliped. With these modifications and an associated behavior pattern, these crabs can efficiently open shells of gastropods and other mollusks and thus feed on the soft parts or enclosed hermit crabs.
Revenge of the NRD: Preferential Degradation of Nonfunctional Eukaryotic rRNA

Eukaryotic cells have several quality control systems that monitor the proper processing of RNAs during RNA biogenesis or the function of cytoplasmic mRNAs. A recent study in Molecular Cell by LaRiviere et al. (2006) shows that after production, mature rRNA is also subject to quality control and nonfunctional ribosomes are targeted for destruction by a novel ribosome surveillance mechanism.
Designing a new form factor for wearable computing

Despite significant improvements in underlying technologies, the wearable computing field is still in its youth. The article offers several methods that can help accelerate the process from vision to product.