cssi/SciSciGPT-SciSciNet huggingface dataset:
How to become a better clinical teacher: A collaborative peer observation process

Background: Peer observation of teaching (PoT) is most commonly done as a way of evaluating educators in lecture or small group teaching. Teaching in the clinical environment is a complex and hectic endeavor that requires nimble and innovative teaching on a daily basis. Most junior faculty start their careers with little formal training in education and with limited opportunity to be observed or to observe more experienced faculty. Aim: Formal PoT would potentially ameliorate these challenges. Methods: This article describes a collaborative peer observation process that a group of 11 clinician educators is using as a longitudinal faculty development program. Results: The process described in this article provides detailed and specific teaching feedback for the observed teaching attending while prompting the observing faculty to reflect on their own teaching style and to borrow effective teaching techniques from the observation. Conclusion: This article provides detailed examples from written feedback obtained during collaborative peer observation to emphasize the richness of this combined experience.
Sequence and properties of the human KB cell and mouse L cell D-loop regions of mitochondrial DNA

The sequences of the displacement-loop (D-loop) regions of mitochondrial DNA (mtDNA) from mouse L cells and human KB cells have been determined and provide physical maps to aid in the identification of sequences involved in the regulation of replication and expression of mammalian mtDNA. Both D-loop regions are bounded by the genes for tRNAPhe and tRNAPro. This region contains the most highly divergent sequences in mtDNA with the exceptions of three small conserved sequence blocks near the 5' ends of D-loop strands, a 225 nucleotide conserved sequence block in the center of the D-loop strand template region, and a short sequence associated with the 3' ends of D-loop strands. A sequence similar to that associated with the 3' termini of D-loop strands overlaps one of the conserved sequence blocks near the 5' ends of D-loop strands. The large, central conserved sequence probably does not code for a protein since no open reading frames are discretely conserved. Numerous symmetric sequences and potential secondary structures exist in these sequences, but none appear to be clearly conserved between species.
Solitary fibrous tumour of the IV ventricle.

Background: Solitary Fibrous Tumour (SFT) is a rare tumour occurring mainly in the pleural cavity, with less than 100 cases reported in the Central Nervous System, where it typically presents as a meningeal-based lesion. We describe the case of a SFT located in the fourth ventricle and briefly review the pertinent literature. Case report: A 61-year-old man presented with a 6-month-history of dizziness, nausea and gait imbalance. Brain magnetic resonance imaging revealed a contrast enhancing, space occupying lesion in the fourth ventricle, with no dural attachment. The patient underwent a sub-occipital craniectomy and total excision of the lesion. Histological examination documented a SFT. The patient is recurrent free at the 2-year follow-up. Conclusion: Although uncommon, SFT should always be included in the differential diagnosis of intraventricular tumours. SFTs of the fourth ventricle are usually benign tumours. Surgery remains the treatment of choice.
SU8-based static diffractive optical elements: wafer-level integration with VCSEL arrays

With the continued miniaturization and sophistication of current generations of semiconductor devices, it is the limitations of data transfer rates that are beginning to impact system performance. Although conventional pathways continue progressing, researchers are moving toward optical interconnects as a potential solution. Optical interconnection is a promising way to replace existing global or chip-to-chip interconnects in future integrated circuits. In contrast to existing metallic wiring, optical interconnects exhibit smaller distance-related loss or distortion of the signal, no deleterious fringing effects and no heat dissipation in the interconnect itself. Pioneering interconnect schemes are currently being developed using both planar waveguides and fibers to distribute optical signals around printed circuit boards. However, researchers are now attempting to incorporate novel, freespace optical interconnects, which will boost data transfer rates by a factor of a thousand. These systems consist of a number of components including vertical cavity surface emitting lasers (VCSELs), lenses, diffractive optical elements and detectors. Integration of single components into sub-systems will help to minimize the optical system footprint for both on-chip and chip-to-chip interconnects. This paper will present the development of both independent and integrated with VCSELs,static diffractive optical element (DOEs) made of SU8 and prove the feasibility of such an approach. SU8 is a negative tone photoresist, conventionally used for high aspect ratio MEMS-based structures. Recent developments in thin film SU8 along with its low absorption at long wavelengths makes it a suitable material for optical applications. By developing a low cost lithography based process, SU-8 DOEs can be efficiently integrated directly on laser sources with minimal effect to VCSEL performance. This approach could have a significant impact on the creation of next generation optical I/O fabrics.
A framework for developing a mimetic tensor artificial viscosity for Lagrangian hydrocodes on arbitrary polygonal meshes

We construct a new mimetic tensor artificial viscosity on general polygonal meshes. The tensor artificial viscosity is based on discretization of coordinate invariant operators, divergence of a tensor and gradient of a vector. The focus of this paper is on the non-symmetric form, div(@[email protected]?u), of the tensor artificial viscosity. The discretizations of this operator is derived for the case of a full tensor coefficient @m. However, in the numerical experiments, we only use scalar @m. We prove that the new tensor viscosity preserves spatial symmetry on special meshes. We demonstrate performance of the new viscosity for the Noh implosion, Sedov explosion and Saltzman piston problems on a set of various polygonal meshes in both Cartesian and axisymmetric coordinate systems.
The Legacy of Black Lynching and Contemporary Segregation in the South

Wacquant (2001) and others have argued that social control efforts directed at racial and ethnic minorities frequently shift institutional form and become more nuanced as societies modernize, even as the underlying function persists. This study examines the connection between southern lynching and housing segregation. We argue that legal, political, social and demographic changes in the south made lynching dysfunctional as a means of control. Among other more nuanced control mechanisms, modern housing segregation helped serve as a replacement. We test this proposition by relating historical southern black lynching rates to recent levels of segregation in southern MSAs. We find that an MSA’s historical lynching rate is positively and significantly linked to the MSA’s current segregation levels after accounting for standard determinants of segregation. Thus, segregation does not just occur generally throughout the south, but follows a very particular pattern based on past lynching rates. Our findings add to a growing literature on the legacy of lynching, such as studies examining contemporaneous variation in support for and use of capital punishment.
Field scale minimization of energy use for groundwater pumping

The limitations on an analytical solution to a groundwater management problem are tested with a field-scale problem and a modification to the analytical solution is proposed. The management problem minimizes the energy used for extracting water from the subsurface. The analytical solution depends on assumptions of linearity, steady state conditions, and adequate water demand to activate all wells and results in a stationarity condition that depends on initial lift and drawdown at each well. The field-scale problem is an aquifer in California with large historical drawdown. Testing of the analytical solution assumptions provides encouragement that the analytical solution may be useful to well-system operators for practical application to minimize energy consumption for pumping.
Evidence for physiological effects of hypercortisolemia in psychiatric patients

Abstract Although some psychiatric patients may have a disorder of hypothalamic-pituitary-adrenal (HPA) function equal in character and severity to that noted in milder cases of Cushing's disease, it is generally accepted that such patients do not show Cushingoid stigmata. This conclusion, however, appears to be based more on clinical observation than on the results of formal scientific investigation. Since some depressed patients appear to overlap with Cushing's disease patients in incidence of such signs and symptoms as amenorrhea, hypertension, sleep disturbance, and insulin resistance, we were interested in examining whether a group of psychiatric patients showing evidence of marked nonsuppression might excess. Nonsuppressors selected on this basis differed slightly from a matched suppressor control group on percentage of polyneutrophils and lymphocytes in blood. A discriminant function constructed from blood sample measurements of 12 factors and systolic/diastolic blood pressure succesfully predicted suppressor or nonsuppressor status in the original and in an independent group of psychiatric patients. A comparison group of Cushing's disease patients was also successfully reclassified on the basis of the discriminant function. These data are interpreted as evidence for a subtle physiological effect of HPA dysregulation and suggest that behavioral symptom complexes may be similarly shaped by changes in this neuroendocrine system. The long-term functional significance of such changes is at present speculative.
Regulating the Anticommons: Insights from Public-Expenditure Theory

This article offers a new interpretation of the traditional Cournot complements problem, or anticommons, by using the theory of public goods to gain a perspective on the problem. Specifically, I examine the pricing strategies and regulation of multiple monopolies that produce products which consumers view as perfect complements. I show that collusion by the firms increases total social welfare and that the collusion problem can be reinterpreted as a problem of provision of public goods from the point of view of the firms. I take this insight further and derive the familiar concepts of the Samuelson marginal condition and the ratio equilibrium for the firms. I compare these outcomes to the first best solution and then apply incentive-compatible mechanisms to strategically implement the Pareto superior ratio-equilibrium outcome and the optimal marginal-cost pricing outcome. Finally, I show how this methodology can be applied to the more familiar Cournot model of oligopoly.
Perceived Barriers and Postsecondary Plans in Mexican American and White Adolescents

The authors examined perceived internal and external barriers to postsecondary educational plans among 140 Mexican American and 296 White high school students, attending to sex, socioeconomic, ethnic differences. Parent education was associated with educational plans. Girls anticipated encountering more barriers associated with financing postsecondary education than their male counterparts. Mexican American students anticipated encountering more postsecondary education barriers associated with ability, preparation, motivation, support, and separation, and expected those barriers to be more difficult to overcome, than their White counterparts. Implications for research and practice are discussed.
Can direct manipulation lower the barriers to computer programming and promote transfer of training?: An experimental study

Novices face many barriers when learning to program a computer, including the need to learn both a new syntax and a model of computation. By constraining syntax and providing concrete visual representations on which to operate, direct manipulation programming environments can potentially lower these barriers. However, what if the ultimate learning goal of the novice is to be able to program in conventional textual languages, as is the case for introductory computer science studentsq Can direct manipulation programming environments lower the initial barriers to programming, and, at the same time, facilitate positive transfer to textual programmingq To address this question, we designed a new direct manipulation programming interface for novices, and conducted an experimental study to compare the programming processes and outcomes promoted by the direct manipulation interface against those promoted by a textual programming interface. We found that the direct manipulation interface promoted significantly better initial programming outcomes, positive transfer to the textual interface, and significant differences in programming processes. Our results show that direct manipulation interfaces can provide novices with a “way in” to traditional textual programming.
The turnover of thiamine and its phosphate esters in rat organs.

Thiamine-deficient rats were injected with [35S]thiamine and the turnover of the injected radioactive thiamine and its phosphate esters was measured in brain, heart, and liver after returning the rats to a normal diet. The radioactivity per gram wet tissue, as well as the specific activity, fell to half its initial value in less than 40 hr, showing that thiamine compounds were turning over rapidly in the body under normal conditions. Furthermore, there was no difference in the rate of turnover of the individual phosphate esters of thiamine. The amount of the various phosphate esters as a percentage of the total thiamine remained the same throughout the experiment.
Effects of heating rate on densification and grain growth during field-assisted sintering of α-Al2O3 and MoSi2 powders

Two types of powders, electrically conductive MoSi2 and insulating α-Al2O3, were sintered by a field-assisted sintering technique (FAST) using heating rates from 50 °C to 700 °C/min. The Al2O3 powders were sintered to 99 pct density at 1100 °C for 2 minutes under 45 Mpa pressure. For Al2O3, no exaggerated grain growth was observed and the final grain size inversely scaled with the heating rate. Such a grain growth behavior fits the literature models based on multiple transport mechanisms for constant-heating-rate sintering. The density reached by MoSi2 under similar sintering conditions was 91 pct. The grain size was independent of the heating-rate value. Specific electrical field and pressure effects are shown to contribute to enhanced densification and minimal coarsening in each material.
Redefining the Role, Scope, and Mission of Community Colleges in an International Context

In an age of globalization, the need exists to understand international affairs, to recognize cultural values other than our own, and to understand world events from a variety of perspectives. Community colleges can play an important role in this context in preparing students to meet the new demands of the 21st century knowledge-based economy. We have to be able to better serve all students that pass through our doors, especially our underserved populations so that we can change lives, families, and communities. This demand must become a major goal of national and state public policy. To an unprecedented extent, more Americans must prepare for, enroll in, and successfully complete degree and certificate programs.
Deletion of intestinal epithelial insulin receptor attenuates high-fat diet-induced elevations in cholesterol and stem, enteroendocrine, and Paneth cell mRNAs

The insulin receptor (IR) regulates nutrient uptake and utilization in multiple organs, but its role in the intestinal epithelium is not defined. This study developed a mouse model with villin-Cre ...
A seminal finding for understanding HIV transmission.

Although the worldwide incidence of HIV infection is high, the retrovirus displays a surprisingly low infectivity in vitro. As a potential explanation for this discrepancy, Munch et al. (2007) now identify and characterize a factor found in human semen that under certain conditions can enhance HIV infectivity by more than 100,000-fold.
Roof bolting in underground mining: a state-of-the-art review

With continuing investigations and developments, roof bolting today can in most cases successfully reinforce the mine roof in underground mining. In order to cope with the increasing use of roof bolts, efforts should be made to maximize the safety and minimize the cost. With regard to mechanical bolting, two important parameters need more advanced improvements and study, namely, optimum design of the shape and type of expansion shell and optimum bolt tension for a specific bolt pattern. For the fully grouted resin bolt, the most critical requirement is to develop a fast-setting, low-cost, intoxic, inflammable grouting material that can be used in the high speed mining cycle. It should be noted that geological conditions such as the strata type, rock properties,in situ stress, and planes of weakness play an important role in the successful application of any roof bolting system. These factors should be specified as accurately and quantitatively as possible in the design of any roof bolting system. Finally, proper and careful installation and continuous monitoring are imperative for the success of any roof bolting system.
Cylindrocyclophanes with Proteasome Inhibitory Activity from the Cyanobacterium Nostoc sp

Material collected from a parkway in the city of Chicago afforded the isolation of a Nostoc species (UIC 10022A). The extract of this strain displayed significant inhibition of the 20S proteasome as well as antiproliferative activity against HT29, MCF7, NCI-H460, and SF268 cancer cell lines. A standardized dereplication protocol allowed for the rapid identification of three known (11-13) and nine new (1-9) chlorinated cylindrocyclophanes from less than 100 mg of organic extract. Scale-up isolation of 1-9 and 11-13 from a larger extract was guided by LC-UV-MS data. In addition, KBr enrichment of the culture media afforded the isolation of a brominated cylindrocyclophane (10). Biological evaluation of 1-5, 9, and 10-13 revealed a large range of activity against the 20S proteasome and allowed the determination of preliminary structure-activity relationships of the cylindrocyclophane pharmacophore.
Large N as a classical limit (1/N ≈ ∋) of mixed valence

Abstract Earlier work has shown that the infinite U Anderson model for mixed valence is contained within a broader ‘slave boson’ field theory. For large spin degeneracy N , the slave boson theory behaves classically with 1/ N playing the role of Planck's constant. Thermal equilibrium is studied in this classical limit. A 2nd order phase transition seperates weak coupling from a strong coupling regime where the boson field has a definite vacuum expectation value, forming a heavy band in the lattice. Quantum fluctuations at finite N convert this phase transition into a smooth crossover characterized by the development of power law correlations in the Bose field.
Cymbidium mosaic virus RNA synthesis in isolated orchid protoplasts

An in vitro protoplast host system has been developed to facilitate the study of cymbidium mosaic virus (CyMV) replication mechanisms. CyMV, a member of the potexvirus group of plant viruses, is among the most significant pathogens of cultivated orchid plants, but a convenient system for studying its molecular genetics has not been available previously. A cDNA probe representing a segment of the CyMV genome was used to detect viral RNA following inoculation of Vanda floral protoplasts with virus particles. Detection was carried out by RNA-DNA hybridization methods (RNA slot blots). Newly synthesized viral RNA was detectable by 6-9 h postinfection and appeared to reach a maximum around 12 h. These results are consistent with the time course of viral RNA synthesis in protoplasts infected with other RNA viruses. Immunoblot detection methods revealed the presence of newly synthesized viral protein indicating that viral gene expression occurs in the protoplasts in addition to genome replication.
Coupled-Transmission-Line Directional Couplers with Coupled Lines of Unequal Characteristic Impedances

A new class of coupled-transmission-line directional couplers, called "nonsymmetrical directional couplers," is described. Unlike conventional directional couplers, nonsymmetrical directional couplers use coupled lines of unequal characteristic impedances. The principal difference between the performance of nonsymmetrical directional couplers and that of conventional designs is the impedance level of the coupled waves, which may be changed to higher or lower impedance levels than that of the incident wave. These directional couplers may be designed to have infinite directivity and to be matched at all frequencies, or they may be designed to have infinite directivity at all frequencies and a specified maximum VSWR. Coupling relationships and design equations for both cases are presented, and the relative properties of both cases are discussed. The theoretical limitation on the maximum coupling and the maximum impedance transformation that can be obtained simultaneously are derived. Techniques for broadbanding by cascading additional sections of coupled limes are described. Experimental results of a trial --10-dB coupler with coupled lines of 50 and 75 ohms are presented.
An Online Modulation Strategy to Control the Matrix Converter Under Unbalanced Input Conditions

Due to absence of a dc-link energy storage element in the direct matrix converter (MC), any abnormality/disturbance in the input voltages is directly reflected on the output voltages. In this paper, a new modulation strategy to control the 3 $\times$ 3 MC under unbalanced input voltage conditions is proposed. The proposed strategy is based on modification of the space vector modulation strategy, which formulates and solves an optimization problem to determine the best switching states and their corresponding optimal duty cycles, such that the errors in the output voltages and the input currents under unbalanced input voltage conditions are minimized. The salient feature of the proposed strategy is its capability to extend the output operating range of the MC. The proposed strategy ensures that optimal performance of the MC over the entire operating range, including the case when the converter operates with an output voltage greater than the maximum attainable balanced output voltage under unbalanced input voltage conditions, is achieved. Performance of the proposed strategy is evaluated and validated based on time-domain simulation studies in the MATLAB/Simulink software environment and experimentation on a scaled-down laboratory prototype.
Absorbing boundary conditions for the simulation of quantum transport phenomena

Abstract Absorbing boundary conditions for the transport equation governing the time evolution of the Wigner distribution function are derived. Local approximations are given which can be used to simulate quantum transport phenomena numerically on a finite domain and a numerical test example is presented.
Film morphology and reaction rate for the CVD of tungsten by the WF 6 —SiH 4 reaction

Low pressure chemical vapor deposition (LPCVD) of tungsten (W) by SiH4 reduction of WF6 on Si(100) surfaces was studied in a single-wafer, cold-wall reactor over a temperature range of 137–385°C and a pressure range of 1-10 Torr at a SiH4/WF6 ratio of 1.0. Rate data were obtained in the absence of gas-phase mass transport limitations and were measured using gravimetric techniques. The amount of tungsten that was deposited varied between 5.79 × 10−5 and 1.70 × 10−2 g/cm2 (∼300−88,000A based on a tungsten density of 19.3 g/cm3), and the rates were between 1.02 × 10−4 and 1.74 × 10−3 g/cm2 min (∼500-9,000A/ min). The apparent overall activation energy increased with pressure; 0.12 eV/ atom at 1 Torr, and 0.40 eV/atom at 10 Torr for short reaction times (0.5–1.5 min). The overall rate was dependent on reaction time (film thickness). Better film morphologies were obtained at higher temperatures and lower pressures. AW(110) preferential orientation was observed at the Si-W interface. Tungsten orientation switched from (110) to (100) as the films grew thicker. Higher apparent activation energies observed at higher pressures were attributed to gas phase reactions and/or by-product readsorption. The interdependence of rate and film morphology was attributed to a reconstruction of W(100) surfaces on which reactant diffusion/surface reaction is favored.
The management of preterm premature rupture of the membranes near the limit of fetal viability

Preterm premature rupture of the membranes near the limit of fetal viability is an uncommon complication of pregnancy, affecting approximately 4 in 1000 gravidas. However, maternal, fetal, and neonatal complications resulting from this condition are significant and include chorioamnionitis, pulmonary hypoplasia, restriction deformities, fetal loss, and complications of extreme prematurity among surviving infants. In this article, we review the literature regarding pregnancy outcomes after preterm premature rupture of the membranes near the limit of viability, and the data on traditional and nontraditional interventions to improve outcomes. An approach to patients who present with preterm premature rupture of the membranes near the limit of viability will be proposed.
Whipple's disease : Is Tropheryma whippelii (Whipple's bacillus) foodborne?

Whipple's disease is a rare systemic disease with symptoms dominated by diarrhea, weight loss, arthralgia or arthritis and abdominal pain. Whipple's disease is limited to humans and the disease is caused by infection with the gram-positive bacterium, Tropheryma whippelii. PCR determinations suggest that T. whippelii is an environmental actinomycete but studies on the organism have been limited due to the inability to culture the organism in vitro. Most patients are male Caucasians older than 50 years of age living in North and South America, England, continental Europe and Australia. The cellular immune system appears to control T. whippelii and patients with cellular immune defects appear to be more susceptible to Whipple's disease. The disease affects the gastrointestinal tract, the central nervous system, cardiovascular system and musculoskeletal system; however, other organs also may be affected. Whipple's disease can be treated with antibiotics effective against gram-positive bacteria but relapses are common. Untreated Whipple's disease is usually fatal. Although the mode of transmission of T. whippelii in humans is unclear, it possibly occurs through the fecal-oral route and food and/or water may be the source of the organism.
Anonymity in a World of Digital Books: Google Books, Privacy, and the Freedom to Read

With its Books project, Google has made an unprecedented effort to aggregate a comprehensive public-access collection of the world’s books. If successful, Google’s collection would become the world’s largest and most broadly accessible public book collection—indeed, project leaders have frequently spoken of their desire to create a “universal library” (Toobin 2007). Still, the Google “library” would differ from established contexts for the provision of free, public access to reading materials—like public libraries—along several policy-related dimensions, of which perhaps the most glaring is its treatment of reader privacy. This paper teases out the specific differences in reader privacy protections between the American public library and Google Books, and what those differences might mean for the values and goals that such contexts have historically embodied. Our analysis is structured by Helen Nissenbaum’s “contextual integrity decision heuristic” (2009), which focuses on revealing changes in informational norms and transmission principles between prevailing and novel settings and practices. Based on this analysis, we recommend a two-pronged approach to alleviating the threats to reader privacy posed by Google Books: both data policy modifications within Google itself and inscription of privacy protections for online reading into federal or international law.
Hydrogen bond coupling in the ketosteroid isomerase active site.

Hydrogenbondnetworksarekeyelementsofbiologicalstructureandfunction.Nevertheless,their structural properties are challenging to assess within complex macromolecules. Hydrogen-bonded protons are not observed in the vast majority of protein X-ray structures, and static crystallographic models provide limited information regarding the dynamical coupling within hydrogen bond networks. We have brought together 1.1-1.3 A u resolution X-ray crystallography, 1 H NMR, site-directed mutagenesis, and deuterium isotope effects on the geometry and chemical shifts of hydrogen-bonded protons to probe the conformational coupling of hydrogen bonds donated by Y16 and D103 in the oxyanion hole of bacterial ketosteroid isomerase. Our results suggest a robust physical coupling of the equilibrium structures of these two hydrogen bonds such that a lengthening of one hydrogen bond by as little as 0.01 A u results in a shortening of the neighbor by a similar magnitude. Furthermore, the structural rearrangements detected by NMR in response to mutations within the active site hydrogen bond network can be explained on the basis of the observed coupling. The results herein elucidate fundamental structural properties of hydrogen bonds within the idiosyncratic environment of an enzyme active site and provide a foundation for future experimental and computational explorations of the role of coupled motions within hydrogen bond networks.
Visual field map clusters in human cortex

We describe the location and general properties of nine human visual field maps. The cortical location of each map, as well as many examples of the eccentricity and angular representations within these maps, are shown in a series of images that summarize a large set of functional MRI data. The organization and properties of these maps are compared and contrasted with descriptions by other investigators. We hypothesize that the human visual field maps are arranged in several clusters, each comprising a group of maps that share a common foveal representation and semicircular eccentricity map. The spatial organization of these clusters suggests that the perceptual processing within each cluster serves related functions.
Differentiation of Adult Leydig Cells in the Neonatal Rat Testis Is Arrested by Hypothyroidism

The effects of propyl thiouracil (PTU)-induced hypothyroidism on testicular interstitial cells and androgen secretion in vitro in the neonatal rat were investigated using Sprague Dawley rats of 1, 7, 14, and 21 days. The results revealed that the fetal Leydig cell (FLC) number per testis was unchanged between and within treatment groups at all ages tested. FLC size was 50% smaller in 21-day controls than in all other groups. Adult Leydig cells (ALCs) were present at Days 14 and 21 in controls but were absent in PTU rats. ALCs approximated FLCs of 21-day controls in size. ALC number per testis showed a sharp increase at Day 21. 11ss-HSD1-positive cells were absent in 21-day PTU testes, but a few were present in 21-day control testes. Testosterone secretion per testis was unchanged in 1- to 21-day controls and 7- to 21-day PTU rats. However, at Day 21, a significantly lower value was seen in controls compared to PTU rats. Testicular androstenedione secretion was not significantly different between control and PTU rats up to 14 days, but a sharp rise was observed in controls at Day 21. At this age, androstenedione levels in PTU rats were similar to those at younger ages. In summary, histological studies showed that hypothyroidism prevented the hypotrophy of FLC and the emergence of ALC in the neonatal rat testis, and agreed favorably with results concerning testicular androgen secretion in vitro. These findings suggest that thyroid hormones have a regulatory role in precursor cell differentiation into Leydig cells in the neonatal rat testis to establish the ALC population.
Migratory Birds and the Dispersal of Arboviruses in California

Abstract. Each spring large numbers of neotropical migrants traversing the Pacific flyway pass through the Coachella Valley enroute to northern destinations, providing an opportunity to test the hypothesis that mosquito-borne encephalitis viruses are introduced annually into California by migratory birds. A total of 5,632 sera were collected from 43 species of migrants during spring (April–June), of which 34 (0.61%) comprised of 14 species tested positive by enzyme immunoassay; only 10 were confirmed by plaque reduction neutralization tests (PRNT). In addition, of 1,109 migrants comprised of 76 species that were reported dead by the public and necropsied, 126 (11%) were positive for West Nile virus (WNV) RNA; however, only three (0.7%) of 428 birds tested during the spring were positive. Limited experimental infection studies with WNV showed that Orange-crowned Warblers were highly susceptible and frequently died, whereas most Yellow Warblers survived. Our results indicated that birds entering California rarely exhibited a history of infection and that most birds probably became infected after entering California.
FLORAL SPECIALIZATION WITHOUT TRADE‐OFFS: OPTIMAL COROLLA FLARE IN CONTRASTING POLLINATION ENVIRONMENTS

Most models of floral specialization assume that adaptations to a particular type of pollinator incur a fitness trade-off in reduced effectiveness of others. To examine this assumption and characterize the form of trade-offs, I manipulated floral form in Dudleya greenei (Crassulaceae), a species that is pollinated by hummingbirds, bumble bees, and other insects. Existing pollination literature predicts that pollination by hummingbirds should favor narrower flowers than pollination by bumble bees. When hummingbirds alone visited experimental populations, narrow flowers indeed performed best by most measures. Hummingbirds showed a slight preference for flowers of intermediate width but deposited more pollen per visit and more pollen overall, and they exported more dye (a pollen analogue) as corolla flare decreased. Bees were more effective than birds at pollinating wide flowers but did not generate overall performance trade-offs. Bees also preferred flowers of intermediate width and deposited more pollen per visit and more pollen overall as corolla flare decreased, but the overall efficiency with which bumble bees exported dye was independent of corolla flare. This demonstrates that phenotypic specialization for hummingbirds might evolve without trading-off the effectiveness of bumble bees. However, both birds and bees tended to transfer dye most efficiently between like phenotypes, suggesting that the form of selection and presence of trade-offs may be frequency dependent in natural populations.
Absorption gratings in photorefractive crystals with multiple levels

Two coherent light beams can couple in any absorbing material owing to a light-induced modulation of the material’s dielectric constant. In photorefractive crystals the coupling caused by these absorption gratings appears in addition to any electro-optic coupling, complicating the interpretation of data. However, in contrast with the electro-optic gratings formed by charge diffusion, absorption gratings do not necessarily vanish as the beam-crossing angle approaches zero if there is more than one absorbing level. We show that a plot of the coupling strength of the absorption gratings versus the beam-crossing angle is characterized by only three parameters, independent of the number of absorbing levels. We use absorption gratings with a two-level model to determine experimentally some important crystal parameters, including the relative density of donors and acceptors in a barium titanate crystal. Our values agree with those obtained from measurements of the bulk light-induced absorption of the crystal.
Summarizing polygenic risks for complex diseases in a clinical whole-genome report

Disease-causing mutations and pharmacogenomic variants are of primary interest for clinical whole-genome sequencing. However, estimating genetic liability for common complex diseases using established risk alleles might one day prove clinically useful. We compared polygenic scoring methods using a case–control data set with independently discovered risk alleles in the MedSeq Project. For eight traits of clinical relevance in both the primary-care and cardiomyopathy study cohorts, we estimated multiplicative polygenic risk scores using 161 published risk alleles and then normalized them using the population median estimated from the 1000 Genomes Project. Our polygenic score approach identified the overrepresentation of independently discovered risk alleles in cases as compared with controls using a large-scale genome-wide association study data set. In addition to normalized multiplicative polygenic risk scores and rank in a population, the disease prevalence and proportion of heritability explained by known common risk variants provide important context in the interpretation of modern multilocus disease risk models. Our approach in the MedSeq Project demonstrates how complex trait risk variants from an individual genome can be summarized and reported for the general clinician and also highlights the need for definitive clinical studies to obtain reference data for such estimates and to establish clinical utility. Genet Med 17 7, 536–544.
Achievable throughput and service delay for imperfect cooperative retransmission MAC protocols

Cooperative retransmission medium access control protocols may be used in a cellular uplink setting to achieve a higher throughput than, say, slotted Aloha, while retaining the advantages of random channel access. When multiple nodes contend for channel access simultaneously, the base station initiates a collision resolution epoch where a set of cooperating nodes retransmit either their own packets, if they were involved in the collision, or the signal that they heard during the collision slot, until the base station has enough linearly independent collided signals to recover the packets. The throughput and service delay of such protocols depends critically on the rate that independent signals may be generated, which in turn depends critically on the underlying channel diversity. We consider two natural models for "imperfect" retransmission schemes where insufficient diversity extends the duration of the retransmission epochs, thus lowering the effective throughput. The throughput optimal medium contention probabilities for both models are obtained as a function of the measure of imperfection. The analysis permits a meaningful and quantitative framework for assessing the strengths and weaknesses of cooperative retransmission MAC protocols.
Brain and behavior: Which way does the shaping go?

Evolutionary contingencies select organisms based on what they can do; brains and other evolved structures serve their behavior. Arguments that brains drive language structure get the direction wrong; with functional issues unacknowledged, interactions between central structures and periphery are overlooked. Evidence supports a peripherally driven central organization. If language modules develop like other brain compartments, then environmental consistencies can engender both structural and functional language units (e.g., the different phonemic, semantic, and grammatical structures of different languages).
Immunochemical studies on blood groups. XLVII. The I antigen complex--precursors in the A, B, H, Lea, and leb blood group system--hemagglutination-inhibition studies.

A partially purified blood group-like substance obtained from milk showed I activity with 2 of 21 anti-I sera. With these antisera, certain human ovarian cyst substances considered to be precursors of the A, B, H, Lea, and Leb substances also showed I activity comparable to the milk material. Strong I activity could be produced by one-stage periodate oxidation and Smith degradation of human ovarian cyst A and B substances, or of hog mucin A + H substance, or by mild acid hydrolysis of human saliva or ovarian cyst blood group B substance. The two sera indicate that I specificity appears at intermediate stages in the biosynthesis of the A, B, H, Lea, and Lea substances. Anti-I sera differ strikingly in their specificities, indicating substantial heterogeneity of the I determinants.
Heparin-binding EGF-like growth factor (HB-EGF) stimulates the proliferation of Müller glia-derived progenitor cells in avian and murine retinas

Muller glia can be stimulated to de-differentiate, proliferate and form Muller glia-derived progenitor cells (MGPCs) that regenerate retinal neurons. In the zebrafish retina, heparin-binding EGF-like growth factor (HB-EGF) may be one of the key factors that stimulate the formation of proliferating MGPCs. Currently nothing is known about the influence of HB-EGF on the proliferative potential of Muller glia in retinas of birds and rodents. In the chick retina, we found that levels of both hb-egf and egf-receptor are rapidly and transiently up-regulated following NMDA-induced damage. Although intraocular injections of HB-EGF failed to stimulate cell-signaling or proliferation of Muller glia in normal retinas, HB-EGF stimulated proliferation of MGPCs in damaged retinas. By comparison, inhibition of the EGF-receptor (EGFR) decreased the proliferation of MGPCs in damaged retinas. HB-EGF failed to act synergistically with FGF2 to stimulate the formation of MGPCs in the undamaged retina and inhibition of EGF-receptor did not suppress FGF2-mediated formation of MGPCs. In the mouse retina, HB-EGF stimulated the proliferation of Muller glia following NMDA-induced damage. Furthermore, HB-EGF not only stimulated MAPK-signaling in Muller glia/MGPCs, but also activated mTor- and Jak/Stat-signaling. We propose that levels of expression of EGFR are rate-limiting to the responses of Muller glia to HB-EGF and the expression of EGFR can be induced by retinal damage, but not by FGF2-treatment. We conclude that HB-EGF is mitogenic to Muller glia in both chick and mouse retinas, and HB-EGF is an important player in the formation of MGPCs in damaged retinas.
Impurity Transport in Alcator C-Mod Plasmas

Trace nonrecycling impurities (scandium and CaF 2 ) have been injected into Alcator C-Mod plasmas in order to determine impurity transport coefficient profiles in a number of operating regimes. Recycling Ar has also been injected to characterize steady-state impurity density profiles. Subsequent impurity emission has been observed with spatially scanning X-ray and vacuum ultraviolet spectrometer systems, in addition to very high spatial resolution X-ray and bolometer arrays viewing the plasma edge. Measured time-resolved brightness profiles of helium-, lithium-, and beryllium-like transitions have been compared with those calculated from a transport code that includes impurity diffusion and convection, in conjunction with an atomic physics package for individual line emission. Similar modeling has been performed for the edge observations, which are unresolved in energy. The line time histories and the profile shapes put large constraints on the impurity diffusion coefficient and convection velocity profiles. In L-mode plasmas, impurity confinement times are short (∼20 ms), with diffusivities in the range of 0.5 m 2 /s, anomalously large compared to neoclassical values. During Enhanced D α (EDA) H-modes, the impurity confinement times are longer than in L-mode plasmas, and the modeling suggests that there exists inward convection (≤50 m/s) near the plasma edge, with greatly reduced diffusion (of order 0.1 m 2 /s), also in the region of the edge transport barrier. These edge values of the transport coefficients during EDA H-mode are qualitatively similar to the neoclassical values. In edge localized mode-free H-mode discharges, impurity accumulation occurs, dominated by large inward impurity convection in the pedestal region. A scaling of the impurity confinement time with H-factor reveals a very strong exponential dependence. In internal transport barrier discharges, there is significant impurity accumulation inside of the barrier foot, typically at r/a = 0.5. Steady-state impurity density profiles in L-mode plasmas have a large up-down asymmetry near the last closed flux surface. The impurity density enhancement, in the direction opposite to the ion B X VB drift, is consistent with modeling of neoclassical parallel impurity transport.
Determinants of national identifications in Ethiopia: a research note

In the voluminous literature on the politics of third world countries, much concern has been expressed about the viability of the new nations. The unsuccessful secessionist efforts of Katanga and Biafra, and the successful breakaway of Bangladesh have heightened these concerns. Scholarly concentration on the problem has produced a number of speculative works on ""nation-building"". Yet these speculations have not been accompanied by the empirical studies necessary to test the propositions offered.
Bladder Autoaugmentation: Early Clinical Experience

AbstractA surgical technique is described in which detrusor muscle over the entire dome of the bladder is excised while leaving the bladder epithelium intact. A large epithelial bulge is created, which functions to augment the storage properties of the bladder without using bowel, and it is referred to as “autoaugmentation”.Seven patients have undergone autoaugmentation of whom 5 have excellent clinical results while 1 has modest improvement. The remaining patient was a technical failure. Postoperative urodynamics in 5 patients demonstrated improved bladder capacity in 3 and markedly improved bladder storage pressures in 4 compared to preoperative studies. The technical aspects of the procedure and patient management are discussed. Autoaugmentation offers potential advantages over enter ocystoplasty, is simple to perform, does not preclude future enterocystoplasty if needed and may be a reasonable alternative to conventional augmentation in selected patients.
Condensed-phase effects on the structural properties of FCH2CN-BF3 and ClCH2CN-BF3: a matrix-isolation and computational study.

We have measured several IR bands of FCH2CN–BF3 and ClCH2CN–BF3 in solid nitrogen, argon, and neon. These bands include the B–F asymmetric stretch (νBFa), the B–F symmetric stretch (νBFs), the BF3 symmetric deformation or “umbrella” mode (δBFs), and the CN stretch (νCN). For both complexes, the frequencies of these modes shift across the various media, particularly the B–F asymmetric stretching band, and thus they indicate that the inert gas matrix environments significantly alter the structural properties of FCH2CN–BF3 and ClCH2CN–BF3. Furthermore, the frequencies shift in a manner that parallels the dielectric constant of these media, which suggests a progressive contraction of the B–N distances in these systems and also that it parallels the ability of the medium to stabilize the increase in polarity that accompanies the bond contraction. We have also mapped the B–N distance potentials for FCH2CN–BF3 and ClCH2CN–BF3 using several density functional and post-Hartree–Fock methods, all of which reveal a f...