cssi/SciSciGPT-SciSciNet huggingface dataset:
Efficacy of surgical simulator training versus traditional wet-lab training on operating room performance of ophthalmology residents during the capsulorhexis in cataract surgery.

Purpose To compare the operating room performance of ophthalmology residents trained by traditional wet-lab versus surgical simulation on the continuous curvilinear capsulorhexis (CCC) portion of cataract surgery. Setting Academic tertiary referral center. Design Prospective randomized study. Methods Residents who chose to participate and provided informed consent were randomized to preoperative CCC training in the wet lab or on a simulator. Residents completed pre-practice demographic questionnaires including habits of daily living. After completion of their preoperative training (wet lab versus simulator), residents performed their first CCC of the clinical rotation under the direct supervision of an attending physician as part of their standard training at the facility. Residents then completed satisfaction questionnaires regarding their preoperative training. Two attending surgeons reviewed and graded each video of operating room performance. The mean score between the 2 attending physicians was used as the individual performance score for each of the 12 performance criteria. The overall score was calculated as the sum of these 12 individual performance scores (standardized). Results Ten residents trained in the wet lab and 11 on the simulator. There was no significant difference in overall score between the 2 groups ( P =.608). There was no significant difference in any individual score except time (wet-lab group faster than simulator group) ( P =.038). Conclusions Preoperative simulator training prepared residents for the operating room as effectively as the wet lab. The time to pass the simulator curriculum was predictive of the time and overall performance in the operating room. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.
Anthropogenic and solar components of hemispheric 14C

A variable solar (helio-magnetic) modulation of the cosmic ray flux causes atmospheric 14C to change on a decadal to century timescale. Ocean-atmosphere exchange rates and atmospheric circulation patterns play a role in Northern-Southern Hemispheric 14C offsets and regional 14C differences that are significant for radiocarbon dating. Time dependent radiocarbon age differences, relative to Washington, were determined for Alaska (A.D. 1884–1932), South Chile (A.D. 1850–1952 and A.D. 1670–1722), Tasmania (A.D. 1895–1950) and Siberia (A.D. 1545–1715). Twentieth century fossil fuel CO2, lacking 14C and mostly released in the Northern Hemisphere (N), has entered the Southern Hemisphere (S) by atmospheric N-S exchange. Regional 14C time series show that initial (19th century) positive N-S 14C offsets switch to negative values by AD 1940. First order carbon reservoir modeling predicts such crossovers.
Effect of iron-chelating agents on inhibitors of ribonucleotide reductase.

Abstract Ribonucleotide reductase from Ehrlich tumor cells is inhibited by hydroxyurea (HU), guanazole (GZ), pyrazolo-imidazole (IMPY), 1-formylisoquinoline thiosemicarbazone (IQ), 4-methyl-5-aminoisoquinoline thiosemicarbazone (MAIQ). and the dialdehydes of inosine and 5′-deoxyinosine. In the presence of EDTA, desferal, or 8-hydroxyquinoline (8-HQ) at a concentration that did not affect reductase activity, HU, GZ and IMPY more effectively inhibited the reductase. EDTA, desferal, or 8-HQ in combination with the nucleoside dialdehyde derivatives did not affect the inhibition caused by these compounds. The combination of these iron-chelating agents with MAIQ and IQ, however, reversed the inhibition caused by MAIQ and IQ. These data indicate that the inhibitors of the nonheme iron-containing component of mammalian ribonucleotide reductase can be subclassified, based on their response to the presence of iron-chelating agents.
STUDIES ON ADENOSINE 5'-PHOSPHOSULFATE REDUCTASE FROM DESULFOVIBRIO DESULFURICANS AND THIOBACILLUS THIOPARUS. I. THE ASSAY AND PURIFICATION.

Abstract An assay procedure for adenosine 5′-phosphosulfate reductase from Desulfovibrio desulfuricans and Thiobacillus thioparus is described that utilizes the AMP-dependent reduction of ferricyanide occurring in the presence of SO32−, and optimum conditions for the assay are reported. The stoichiometry of this oxidation was determined and indicates that the reaction proceeds as follows: AMP + SO32− + 2Fe(CN)63− → adenosine 5′-phosphosulfate + 2Fe(CN)64−. Other nucleotides, deAMP, IMP, and GMP, can replace AMP in the reaction. Employing this assay, adenosine 5′-phos phosulfate reductase was purified from extracts of D. desulfuricans, and the purified enzyme, essentially homogenous in the ultracentrifuge, contains flavin adenine dinucleotide and iron. Inhibition of the enzyme by p-hydroxymercuribenzoate and reversal of the inhibition by monothiols indicate that one or more sulfhydryl groups are required for activity.
Naltrexone fails to block the acquisition or expression of a flavor preference conditioned by intragastric carbohydrate infusions.

Abstract The effects of naltrexone on the expression and acquisition of flavor preferences conditioned by the postingestive actions of carbohydrates were investigated. Food-restricted rats (Experiment 1) were given one-bottle training with one flavored saccharin solution (CS+) paired with intragastric (IG) infusions of 16% sucrose, and another flavored saccharin solution (CS−) paired with water infusions. In two-bottle tests CS+ was preferred to CS−, and naltrexone (1.0–5.0 mg/kg) reduced total intake but not CS+ preference. In Experiment 2 food-restricted rats that received naltrexone (0.1 or 1.0 mg/kg; NTX group) throughout one-bottle training consumed less CS+ and CS− than did saline-treated control rats. Yet, the NTX and control groups displayed similar CS+ preferences during two-bottle tests when treated with saline or naltrexone (0.1–5.0 mg/kg). In Experiment 3, rats were trained to accept more CS+ than CS− in one-bottle tests. Naltrexone (0.1–2.5 mg/kg) reduced the one-bottle intakes of both solutions, and the rats continued to consume more CS+ than CS−. We conclude that the opioid system modulates the consumption of flavored solutions, but is not critically involved in the acquisition or expression of flavor preferences conditioned by IG carbohydrate.
Behavioral economic approaches to reduce college student drinking

There is a need for novel, theory-based approaches to reduce heavy drinking on college campuses. Behavioral economics has guided basic laboratory research on drug administration for over 30 years and has recently been applied to human substance use in naturalistic and clinical settings. This paper provides an introduction to behavioral economics, reviews applications of behavioral economics to college student drinking, and describes prevention and intervention strategies that are consistent with behavioral economic theory. Behavioral economic theory predicts that college students' decisions about drinking are related to the relative availability and price of alcohol, the relative availability and price of substance-free alternative activities, and the extent to which reinforcement from delayed substance-free outcomes is devalued relative to the immediate reinforcement associated with drinking. Measures of problem severity are based on resource allocation towards alcohol and the relative value of alcohol compared to other reinforcers. Policy and individual level prevention approaches that are consistent with behavioral economic theory are discussed, including strategies for increasing the behavioral and monetary price of alcohol, increasing engagement in rewarding alternatives to substance use, and counteracting student drinkers' tendency to overvalue immediate relative to delayed rewards.
A Laboratory Study of High-Temperature Corrosion on Fireside Surfaces of Coal-Fired Steam Generators

Three experimental approaches gave significant information on high-temperature fireside corrosion: 1 Sodium and potassium chlorides, injected through a gas flame, were deposited as such and then converted to sulfates on an iron surface. 2 Samples of mixed alkali and iron sulfates first showed decomposition and then formed melts at temperatures as low as 1070 deg F. This temperature is within the range that might be expected for fireside surface temperatures on superheater and reheater tubes of large steam generators. 3 Alkali metal chlorides and sulfates, in partial coverage of metal disks and in a flue gas atmosphere, formed fused deposits at temperatures as low as 900 deg F. Complex alkali iron sulfates may cause corrosion either by direct electrolytic corrosion or by altering the normally protective iron oxide scale so that the metal is exposed to direct oxidative corrosion.
Ray-matrix approach for diffractive optics

Ray matrices are a powerful tool for the analysis of optical systems. This technique is modified to include a diffractive optical element within the optical system. Several research applications are discussed, including optical Fourier transforms and imaging with diffractive optical elements.
Temperament in middle childhood: A behavioral genetic analysis of fathers’ and mothers’ reports

The genetic and environmental sources of variance in mothers’ and fathers’ ratings of child temperament in middle childhood were estimated and compared. Parents of 88 MZ twin pairs and 109 same-sex DZ twin pairs completed a temperament questionnaire. For Effortful Control, significant genetic and environmental effects were indicated across mothers’ and fathers’ ratings, but parent differences were found for the Negative Affectivity factor. When present, sibling contrast effects were not consistent for mothers and fathers. Parental ratings of the Effortful Control factor were best explained by the Biometric model whereas the Negative Affectivity factor was best explained by the Rater Bias model. Overall, mothers’ and fathers’ ratings yielded similar evidence of genetic and environmental etiology of temperament in middle childhood.
Antimicrobe.org: An Online Reference for the Practicing Infectious Diseases Specialist

Antimicrobe.org (http://www.antimicrobe.org) is a World Wide Web-based version of the textbook Antimicrobial Therapy and Vaccines, volumes I and II. The Web site currently consists of 3 texts (Microbes, Antimicrobial Agents, and HIV Clinical Manual) and will soon include a fourth, Empiric. The Web site focuses on therapy for infectious diseases, and it covers, in comprehensive detail, a great majority of infections encountered today. The dynamic nature of a Web-based reference allows for information to be frequently updated and enhances a physician's searching capabilities to find answers to very specific clinical questions and the latest available evidence. A Smart Search engine allows users to ask specific questions and to find focused answers, either within the textbook or through PubMed via a guided PubMed references option. The Web site also provides clinical vignettes and minireviews on hot topics in infectious diseases and hyperlinks to other important articles or Web sites. Chapters are written by experts in their field who provide evidence-based information, as well as anecdotal reports about rare infections. Antimicrobe.org would be of great benefit to physicians who treat infections on a routine basis.
CHARACTERIZATIONS OF DISTRIBUTION OF RATIO OF RAYLEIGH RANDOM VARIABLES

Various characterizations of the distribution of the ratio of two independent Rayleigh random variables are presented. These characterizations are based, on a truncated moment; on hazard function; and on certain functions of order statistics.
TNF in combination with GM‐CSF enhances the differentiation of neonatal cord blood stem cells into dendritic cells and macrophages

We describe dendritic cell progenitors within the CD34+ stem cell compartment in neonatal cord blood and identify growth factors contributing to their differentiation. Granulocyte-macrophage colony-stimulating factor (GM-CSF), although mainly promoting the growth and differentiation of monocyte-macrophages (mono-m psi s), also induced the differentiation of cells with the distinctive morphological features of dendritic cells (DCs). Tumor necrosis factor (TNF) in combination with GM-CSF promoted further growth of both cell types but most notably increased the DC content. In situ analysis revealed that the cells exhibiting DC morphology were positive for class II major histocompatibility complex antigens but were CD14 negative, did not exhibit nonspecific esterase activity, and were nonphagocytic. Moreover, the mixed leukocyte reaction stimulatory capacity of cultures with the higher DC content was greater. TNF, interleukin-1 (IL-1), IL-6, or platelet-derived growth factor (PDGF) was inactive in promoting stem cell proliferation or DC morphology. IL-1 or PDGF synergized with GM-CSF to increase mono-m psi-associated cell proliferation but did not increase the DC content. The development of a common DC-monocyte precursor was suggested by the presence of colony-forming unit-like clusters containing mono-m psi s and DCs and one sharp proliferative peak. The loss of DC morphology after 21 days, coupled with increases in mono-m psi-associated markers and a constant number of viable cells, further suggests that DC morphology may fluctuate in culture or is a transient feature acquired by certain cells of the mono-m psi lineage.
The relationship between depressive symptoms, diabetes symptoms, and self-management among an urban, low-income Latino population

Abstract Objective To investigate the prevalence of depression symptoms among Latinos with diabetes following transition from hospital to home and the relationship of depressive symptoms to diabetes symptom severity and self-management activities. Methods 203 Latino patients with diagnosed diabetes completed a survey assessing depressive symptoms (PHQ-9), diabetes symptom severity, and diabetes self-management activities (SDSCA). Characteristics and diabetes outcomes between patients with and without probable major depression were compared. Associations between PHQ-9 scores and diabetes outcomes were assessed. Multivariate regression models evaluated the relationship between depressive symptoms and diabetes outcomes and exercise after controlling for patient characteristics. Results 31.5% of participants indicated probable major depression (PHQ-9 ≥ 10). More severe diabetes symptoms and less reported exercise were associated with higher PHQ-9 scores. Regression models showed no relationship between self-management and depression. More severe diabetes symptoms were significantly associated with being female, married, and having probable major depression. Odds of exercising were reduced by 6% for every one-unit increase in PHQ-9 score. Conclusions The prevalence of probable depressive symptoms is high in this population. Having depressive symptoms is an indicator of poorer diabetes symptoms. Screening for depressive symptoms may help identify individuals who need additional support with diabetes symptom and self-management.
A Framework for Effective Annotation of Information from Closed Captions Using Ontologies

To improve the accuracy in terms of precision and recall of an audio information retrieval system we have created a domain-specific ontology (a collection of key concepts and their interrelationships), as well as a novel, pruning algorithm. Given the shortcomings of keyword-based techniques, we have opted to employ a concept-based technique utilizing this ontology. Achieving high precision and high recall is the key problem in the retrieval of audio information. In traditional approaches, high recall is typically achieved at the expense of low precision, and vice versa. Through the use of a domain-specific ontology appropriate concepts can be identified during metadata generation (description of audio) or query generation, thus improving precision. When irrelevant concepts are associated with queries or documents there is a loss of precision. On the other side of the coin, if relevant concepts are discarded, a loss of recall will ensue. In conjunction with the use of a domain specific ontology we have thus proposed a novel, automatic pruning algorithm which prunes as many irrelevant concepts as possible during any case of description and identification of documents, and query generation. To improve recall, A controlled and correct query expansion mechanism is proposed for the improvement of recall, thus guaranteeing that precision will not be lost. We have constructed a demonstration prototype, and experimentally and analytically we have shown that our model, compared to keyword search, achieves a significantly higher degree of precision and recall.
17O NMR studies on polycyclic quinones, hydroxyquinones and related cyclic ketones: Models for anthracycline intercalators

The 17O chemical shifts for six cyclic ketones which serve as models for quinones, viz. cyclohex-2-enone (1), α-tetralone (2), anthrone (3), 4H-pyran-4-one (4), 1-benzopyran-4(4H)-one (5), xanth-9-enone (6), and for six quinones, viz. benzoquinone, naphthoquinone, anthraquinone, 2,5-dihydroxybenzoquinone 5,8-dihydroxynaphthoquinone and 1,4-dihydroxyanthraquinone, were measured in toluene at 90°C. A shielding effect of approximately 50 ppm per fused benzene ring was noted for the quinones and related carbocyclic ketones; however, the analogous series of heterocyclic fused ring ketones 4–6 showed only a slight fused-ring effect on the carbonyl chemical shift. A single 17O resonance was observed for 2,5-dihydroxybenzoquinone (358 ppm) and 5,8-dihydroxynaphthoquinone (283 ppm), indicating rapid proton exchange between the oxygen atoms of these compounds. However, 1,4-dihydroxyanthraquinone gave two discrete 17O signals at 441 and 87 ppm, indicating that in this case proton exchange between oxygen atoms is slow.
The Relationship Between Organizational Size and Turnover: A Longitudinal Investigation

This research investigated the relationship between organizational size and turnover, using longitudinal data and time-series statistical methods. Four measures of turnover (accession rate, voluntary separation rate, involuntary separation rate, and mean tenure of those leaving the organization) were computed on a monthly basis for 65 months. After ARIMA modeling, each series was cross-correlated with a series based on organization size to investigate the relationship between turnover and size over time. The clearest relationships found were for the accession rate and average tenure of weavers; the more interesting relationships to voluntary and involuntary separations, however, were not found to be significant. Results are discussed from the perspective of temporal relationships, and the viewpoint of organizations as dynamic systems.
Characterization of a Red Jungle Fowl by White Leghorn Backcross Reference Population for Molecular Mapping of the Chicken Genome

Abstract A reference population designed for molecular genetic mapping of the chicken genome was produced by backcrossing a partially inbred Red Jungle Fowl (JF) line to a highly inbred White Leghorn (WL) line. The parental lines were chosen to maximize the expected genetic polymorphisms between them. Two full-sib F1 males, produced by crossing a JF male with a WL female, were each individually mated to about 10 WL females to produce 400 progeny. All the progeny were classified for segregation of three loci controlling color phenotype and six blood group loci, some of which have been mapped by classical methods. Segregation of these nine loci did not differ significantly from the expected 1:1 ratio with one exception. At least 20 mL of whole blood was stored from all the parents and progeny to provide DNA for molecular analysis. Screening of the parental lines and F1 crosses by Southern blot with cloned genes and by the random amplified polymorphic DNA (RAPD) procedure revealed a large number of molecular markers mat were parental line-specific. A preliminary analysis of 16 backcross progeny classified for polymorphisms at 2 color loci, 6 blood group loci, 16 loci detected by cloned chicken genes, and 4 loci detected by the RAPD method has been completed. Segregation at 27 out of 28 loci did not differ significantly from the expected 1:1 ratio, showing that two alternative alleles were detected at each locus. Five pairs of linked loci were detected (P ≤ .01). Thus, this population is polymorphic and gives simple segregation for two types of molecular probes, providing a good resource for collaborative mapping of the chicken genome.
Simple algorithm for isothermal–isobaric molecular dynamics

We review principles of non-Hamiltonian statistical mechanics and present a new set of equations and integration algorithm for isothermal-isobaric dynamics. The chief advantage of the present scheme is that it is somewhat simpler than previous methods. We perform numerical simulations to test the accuracy of the algorithm and compare its stability to that of a "gold standard," a symplectic integrator for Hamiltonian dynamics of the same system. The stability of the isothermal-isobaric algorithm is comparable to the stability of the symplectic integrator.
Activity supervision and behavior understanding model in distance education

This paper presents an advanced Petri Net model to analyze the workflow of a web-based multiple participants virtual environment. The presented approach not only can conspicuously help the developer to comprehend the interaction relationship between the client-server virtual environments but also to easily construct a shared virtual world. We proposed a system based on the scaffolding theory. Behaviors of students are supervised by an intelligent control system, which is programmed by the instructor under our generic interface. Problems of providing the multi-user interaction on the Web and the solutions proposed by the Petri Net model are fully elaborated here. This paper can be used as a basic/fundamental research framework and tools to study and understand the characteristics of e-learning and to explore its optimal education application.
Real-Time Inference for a Gamma Process Model of Neural Spiking

With simultaneous measurements from ever increasing populations of neurons, there is a growing need for sophisticated tools to recover signals from individual neurons. In electrophysiology experiments, this classically proceeds in a two-step process: (i) threshold the waveforms to detect putative spikes and (ii) cluster the waveforms into single units (neurons). We extend previous Bayesian nonparametric models of neural spiking to jointly detect and cluster neurons using a Gamma process model. Importantly, we develop an online approximate inference scheme enabling real-time analysis, with performance exceeding the previous state-of-the-art. Via exploratory data analysis—using data with partial ground truth as well as two novel data sets—we find several features of our model collectively contribute to our improved performance including: (i) accounting for colored noise, (ii) detecting overlapping spikes, (iii) tracking waveform dynamics, and (iv) using multiple channels. We hope to enable novel experiments simultaneously measuring many thousands of neurons and possibly adapting stimuli dynamically to probe ever deeper into the mysteries of the brain.
Radionuclide Imaging of Infection: In Search of the Grail

Although there have been significant advances in the understanding of the pathogenesis of infection, it remains a major cause of patient morbidity and mortality throughout the world ( [1][1] ). The presence of infection may be suggested by signs and symptoms such as pain, fever, general malaise, and
Effects of repeated weight loss and regain on body composition in obese rats.

To test the hypothesis that repeated loss and gain of weight through dieting will result in increasing fatness, 200-g female Sprague-Dawley rats were castrated and allowed to become obese on a high-fat diet for 6 wk. Two successive periods of severe food restriction (50% maintenance for 28 d and 25% maintenance for 21 d) were each followed by ad libitum refeeding on the high-fat diet until control body weights were attained. Percent body fat was determined indirectly from body density and total-body water at the end of each cycle. Re- stricted rats gained weight and attained control body weights on ad libitum feeding without overshooting these weights, and percentage body fat was not different from that of controls at the end of either cycle (cycle 1 22.3 ± 1.7 vs 23.8 ± 1.7%; cycle 2 19.0 ± 1.1 vs 21.6 ± 0.8%). Repeated cycles of weight loss and regain do not produce increased body fatness or decreased rate of weight loss in ovariectomized rats. Am J C/in Nutr l988;47:393-9.
Analytic signal space partitioning and symbolic dynamic filtering for degradation monitoring of electric motors

This study presents an application of the recently reported theories of analytic signal space partitioning (ASSP) and symbolic dynamic filtering (SDF) to address degradation monitoring in permanent magnet synchronous motors (PMSM). An (experimentally validated) mathematical model of generic PMSM is chosen to monitor degradation/fault events on a simulation test bed; and the estimated parameter of health condition is observed to vary smoothly and monotonically with degradation in magnetization of the PMSM.
Structural relationships between mutagenicity, maximum tolerated dose, and carcinogenicity in rodents

The CASE structure-activity relational system was applied to a study of the structural bases of toxicity as expressed in the maximum tolerated dose (MTD) of a group of chemicals for which rodent carcinogenicity and mutagenicity data were also available. All of the results were obtained under the aegis of the U.S. National Toxicology Program. The analyses revealed that there was a structural basis for the MTD in mice and in rats and that these overlapped considerably. There was also some overlap between structural determinants of the MTD and of carcinogenicity in rodents but there was also a significant "antagonism" between such fragments; i.e., fragments associated with high toxicity (low MTD) were associated with lack of carcinogenicity and vice versa. The highest overlaps observed were between the structural determinant for a low MTD (i.e., high toxicity) and mutagenicity in Salmonella.
A CCl4/CHCl3 interaction study in isolated hepatocytes: selection of a vehicle.

Abstract Emulphor, ethanol, and dimethyl sulfoxide (DMSO) were evaluated as vehicles in studying the toxicity of CCl4 and CHCl3 in isolated hepatocytes. The appropriateness of the vehicle was determined by evaluating the following parameters: solubility of CCl4 and CHCl3 in the vehicle, cell injury (intracellular K+), cell death (LDH leakage), and lack of interaction (protection or enhanced toxicity) with CCl4 and CHCl3. The relative toxicity of the vehicles according to maximum no effect levels ( v v ) was: emulphor (0.125%) > ethanol (1.0%) > DMSO (5.0%). Emulphor at toxic levels was inadequate to dissolve enough CCl4 to evaluate in this system. Ethanol (5.0, 2.5, 1.0, 0.5%) was more toxic than DMSO and interacted with both CCl4 and CHCl3 to enhance toxicity. DMSO (15.0, 5.0, 2.5%) did not significantly alter the toxicity of CCl4 and CHCl3; no interaction. These data suggest that DMSO should be the vehicle for evaluating the toxicity of CCl4 and CHCl3 and their mechanisms of action in the isolated hepatocyte.
Divisor Classes on an Abelian Variety

In the last chapter we defined various equivalence relations, and we shall now determine the structure of the factor groups for these equivalence relations in the group of divisors of an abelian variety A. We have inclusions $$D(A) \supset {D_T}(A) \supset {D_a}(A) \supset {D_\iota }(A).$$
Cytoplasmic dynein pushes the cytoskeletal meshwork forward during axonal elongation

During development, neurons send out axonal processes that can reach lengths hundreds of times longer than the diameter of their cell bodies. Recent studies indicate that en masse microtubule translocation is a significant mechanism underlying axonal elongation, but how cellular forces drive this process is unknown. Cytoplasmic dynein generates forces on microtubules in axons to power their movement through 'stop-and-go' transport, but whether these forces influence the bulk translocation of long microtubules embedded in the cytoskeletal meshwork has not been tested. Here, we use both function-blocking antibodies targeted to the dynein intermediate chain and the pharmacological dynein inhibitor ciliobrevin D to ask whether dynein forces contribute to en bloc cytoskeleton translocation. By tracking docked mitochondria as fiducial markers for bulk cytoskeleton movements, we find that translocation is reduced after dynein disruption. We then directly measure net force generation after dynein disruption and find a dramatic increase in axonal tension. Taken together, these data indicate that dynein generates forces that push the cytoskeletal meshwork forward en masse during axonal elongation.
Microsatellites Are Molecular Clocks That Support Accurate Inferences about History

Microsatellite length mutations are often modeled using the generalized stepwise mutation process, which is a type of random walk. If this model is sufficiently accurate, one can estimate the coalescence time between alleles of a locus after a mathematical transformation of the allele lengths. When large-scale microsatellite genotyping first became possible, there was substantial interest in using this approach to make inferences about time and demography, but that interest has waned because it has not been possible to empirically validate the clock by comparing it with data in which the mutation process is well understood. We analyzed data from 783 microsatellite loci in human populations and 292 loci in chimpanzee populations, and compared them with up to one gigabase of aligned sequence data, where the molecular clock based upon nucleotide substitutions is believed to be reliable. We empirically demonstrate a remarkable linearity (r(2) > 0.95) between the microsatellite average square distance statistic and sequence divergence. We demonstrate that microsatellites are accurate molecular clocks for coalescent times of at least 2 million years (My). We apply this insight to confirm that the African populations San, Biaka Pygmy, and Mbuti Pygmy have the deepest coalescent times among populations in the Human Genome Diversity Project. Furthermore, we show that microsatellites support unbiased estimates of population differentiation (F(ST)) that are less subject to ascertainment bias than single nucleotide polymorphism (SNP) F(ST). These results raise the prospect of using microsatellite data sets to determine parameters of population history. When genotyped along with SNPs, microsatellite data can also be used to correct for SNP ascertainment bias.
The safety dance: Men without [hard] hats

A central tenet in the sociology of risk is that risk-taking is inherently linked to masculinity. Recent research, however, demonstrates gender identity is only one of the many social contexts that influence professional risk-taking. The interaction between the various occupational social contexts – such as social class, occupational socialisation, institutions, and gender identity – contributes to the development of risk-taking occupational identities. These occupational identities are associated with unique understandings of risk which influence whether workers are likely to embrace or avoid risk. While there has been a plethora of research exploring how occupational identities encourage risk-taking, relatively little research has explored how occupational identities determine the types of risks embraced by workers. After all, there is substantial occupational variation in the types of risks workers take. In this paper I draw on data from a series of interviews conducted in 2010 and 2011 with US electri...
From the Field to the Classroom: The Boll Weevil's Impact on Education in Rural Georgia

I examine how production of a child labor–intensive crop (cotton) impacted schooling in the early twentieth-century American South. Because cotton production may be endogenous, presence of an agricultural pest (the boll weevil) is employed as an instrument. Using newly collected county-level data for Georgia, I find a 10 percent reduction in cotton caused a 2 percent increase in African-American enrollment rate, but had little effect on white enrollment. The shift away from cotton following the boll weevil’s arrival explains 30 percent of the narrowing of the racial differential in enrollment rates between 1914 and 1929.
Stream Salamanders Accurately Assess Size-Dependent Predation Threats

Individual size is an important determinant of the outcomes of inter- and intraspecific interactions. Different-sized members of a guild might represent prey, competitors, or predators. Although direct predation rates might be low, trait-mediated indirect effects of predators on prey can yield altered activity, microhabitat use, survival, and growth. If individuals respond to all sizes of a predator regardless of the predation threat, antipredator behaviors might incur costs for prey as they forgo foraging opportunities or experience predation by other predators. Accurate assessment of predation risk would minimize costs resulting from antipredator behavior. We evaluated the ability of larval salamanders to assess predation risk and alter their habitat selection in response to intraguild competitors and predators. Specifically, we assessed behavioral responses to the presence of a conspecific, a similarly sized heterospecific, and a small or large individual of a predatory species. We predicted that larval salamanders would select habitat differently in the presence of a large predatory heterospecific, but not in the presence of similarly sized heterospecifics or conspecifics. The focal species occupied habitat 29 6 0.02% farther from a large heterospecific predator than from small heterospecifics, even if the heterospecifics were smaller individuals of the predatory species. The focal species also exhibited escape behaviors only in the presence of the large members of the predatory species. These data indicate that salamander larvae can assess size-specific predation threats, minimizing predation risk through use of antipredator behaviors.
Impedance Analysis of Electrochemical NOx Sensor Using a Au/Yttria-Stabilized Zirconia (YSZ)/Au cell

An electrochemical cell employing a YSZ electrolyte and two Au electrodes was utilized as a model system for investigating the mechanisms responsible for impedance metric NO{sub x} (NO and NO{sub 2}) sensing. The cell consists of two dense Au electrodes on top of a porous/dense YSZ bilayer structure (with the additional porous layer present only under the Au electrodes). Both electrodes were co-located on the same side of the cell, resulting in an in-plane geometry for the current path. The porous YSZ appears to extend the triple phase boundary and allows for enhanced NO{sub x} sensing performance, although the exact role of the porous layer is not completely understood. Impedance data were obtained over the frequency range of 0.1 Hz to 1 MHz, and over a range of oxygen (2 to 18.9%) and NO{sub x} (10 to 100 ppm) concentrations, and temperatures (600 to 700 C). Data were fit with an equivalent circuit, and the values of the circuit elements were obtained for different concentrations and temperatures. Changes in a single low-frequency arc were found to correlate with concentration changes, and to be temperature dependent. In the absence of NO{sub x}, the effect of O{sub 2} on the low-frequency resistancemore » could be described by a power law, and the temperature dependence described by a single apparent activation energy at all O{sub 2} concentrations. When both O{sub 2} and NO{sub x} were present, however, the power law exponent varied as a function of both temperature and concentration, and the apparent activation energy also showed dual dependence. Adsorption mechanisms are discussed as possibilities for the rate-limiting steps.« less
Comparison of Methods for Feeding Blood to Tabanus nigrovittatus in the Laboratory

Females collectively presented warmed (31°—37°C), citrated beef blood from saturated Kimwipes imbibed more blood (x = 51.4 µl) than the other 3 methods tested. Grouped females presented warmed blood from Parafilm bags imbibed an avg of 40.3 µl, individual females in large (450 ml) containers imbibed 39.5 µl while individual females in small (35 ml) containers imbibed 4.3 µl. Twenty of 25 individually fed females in large containers and 1 of 25 individuals fed in small containers took blood meals exceeding their pre-fed weight. Based on an avg pre-fed weight of 25 females, 35 of the 50 grouped females tested took blood meals exceeding-the pre-fed avg weight.
Improved hemocompatibility of silicone rubber extracorporeal tubing via solvent swelling-impregnation of S-nitroso-N-acetylpenicillamine (SNAP) and evaluation in rabbit thrombogenicity model

Abstract Blood-contacting devices, including extracorporeal circulation (ECC) circuits, can suffer from complications due to platelet activation and thrombus formation. Development of nitric oxide (NO) releasing polymers is one method to improve hemocompatibility, taking advantage of the ability of low levels of NO to prevent platelet activation/adhesion. In this study a novel solvent swelling method is used to load the walls of silicone rubber tubing with the NO donor S-nitroso-N-acetylpenicillamine (SNAP). This SNAP-silicone rubber tubing exhibits an NO flux of ca. 1 × 10−10 mol cm−2 min−1, which mimics the range of NO release from the normal endothelium, which is stable for at least 4 h. Images of the tubing before and after swelling, obtained via scanning electron microscopy, demonstrate that this swelling method has little effect on the surface properties of the tubing. The SNAP-loaded silicone rubber and silicone rubber control tubing are used to fabricate ECC circuits that are evaluated in a rabbit model of thrombogenicity. After 4 h of blood flow, the SNAP-loaded silicone rubber circuits were able to preserve the blood platelet count at 64% of baseline (vs. 12% for silicone rubber control). A 67% reduction in the degree of thrombus formation within the thrombogenicity chamber was also observed. This study demonstrates the ability to improve the hemocompatibility of existing/commercial silicone rubber tubing via a simple solvent swelling-impregnation technique, which may also be applicable to other silicone-based blood-contacting devices. Statement of Significance Localized nitric oxide (NO) release can be achieved from biomedical grade polymers doped with S-nitroso-N-acetylpenicillamine (SNAP). Despite the promising in vitro and in vivo biocompatibility results reported for these NO releasing polymers, many of these materials may face challenges in being translated to clinical applications, especially in the areas of polymer processing and manufacturing. In this study, we report a solvent swelling-impregnation technique to incorporate SNAP into extracorporeal circuit (ECC) tubing. These NO-releasing ECCs were able to attenuate the activation of platelets and maintain their functionality, while significantly reducing the extent of thrombus formation during 4 h blood flow in the rabbit model of thrombogenicity.
Virulence Potential of Activatable Shiga Toxin 2d-Producing Escherichia coli Isolates from Fresh Produce.

Shiga toxin (Stx)–producing Escherichia coli (STEC) strains are food- and waterborne pathogens that are often transmitted via beef products or fresh produce. STEC strains cause both sporadic infections and outbreaks, which may result in hemorrhagic colitis and hemolytic uremic syndrome. STEC strains may elaborate Stx1, Stx2, and/or subtypes of those toxins. Epidemiological evidence indicates that STEC that produce subtypes Stx2a, Stx2c, and/or Stx2d are more often associated with serious illness. The Stx2d subtype becomes more toxic to Vero cells after incubation with intestinal mucus or elastase, a process named “activation.” Stx2d is not generally found in the E. coli serotypes most commonly connected to STEC outbreaks. However, STEC strains that are stx2d positive can be isolated from foods, an occurrence that gives rise to the question of whether those food isolates are potential human pathogens. In this study, we examined 14 STEC strains from fresh produce that were stx2d positive and found that they...
Irritable bowel syndrome colon cell phenotypic change of Th

[Objective] To investigate the expressions of Th1 cytokin IFN-r,IL-12 and Th2 cytokin IL-4,IL-10 intestinal mucosa in patients with irritable bowel syndrome (IBS).[Methods] Mucosal specimens were harvested from ascending,descending colon and rectum by colonscopy in 60 patients with IBS and 20 healthy controls,and were observed for inflammation with HE staining.The mRNA expression of IFN-r,IL-12,IL-4 and IL-10 were examined by RT-PCR.[Results] The large intestinal mucosa of patients with IBS were generally normal both under colonscopy and conventional histologic assessment on HE stained sections.Compared with controls,the expressions of Th1 cytokine (IFN-r) in the ascending,descending colon and rectum were significantly increased in diarrhea-predominant IBS (D-IBS) patients.The expression of interleukin 12 (IL-12) in the rectum was also significantly increased.However,the expression of Th2 cytokin (IL-4) was no significant difference and Th2 cytokin (IL-10) was decreased in D-IBS patients,but no significant difference compared with controls.The expression of IFN-r in post-infection IBS (PI-IBS) patients was increased significantly compared with controls among D-IBS patients.Besides,IL-12 in the ascending colon and rectum were significantly increased.The expression IL-4 and IL-10 in the PI-IBS patients were decreased,but no significant difference compared with controls.The expression of Th1 and Th2 cytokines in non PI-IBS patients had no significant difference compared with controls.In constipation-predominant IBS (C-IBS) patients,the expression of Th1 and Th2 cytokines had no statistical difference compared with controls.[Conclusion] The shift of Th1/Th2 balance of colon and rectal mucosa in D-IBS patients was demonstrated along with the enhanced Th1 activity.Infection affected the shift of Th balance in D-IBS patients,which provide a new way for treatment of PI-IBS.
Detailed analysis of an optimized FPP-based 3D imaging system

In this paper, we present detail analysis and a step-by-step implementation of an optimized fringe projection profilometry (FPP) based 3D shape measurement system. First, we propose a multi-frequency and multi-phase shifting sinusoidal fringe pattern reconstruction approach to increase accuracy and sensitivity of the system. Second, phase error compensation caused by the nonlinear transfer function of the projector and camera is performed through polynomial approximation. Third, phase unwrapping is performed using spatial and temporal techniques and the tradeoff between processing speed and high accuracy is discussed in details. Fourth, generalized camera and system calibration are developed for phase to real world coordinate transformation. The calibration coefficients are estimated accurately using a reference plane and several gauge blocks with precisely known heights and by employing a nonlinear least square fitting method. Fifth, a texture will be attached to the height profile by registering a 2D real photo to the 3D height map. The last step is to perform 3D image fusion and registration using an iterative closest point (ICP) algorithm for a full field of view reconstruction. The system is experimentally constructed using compact, portable, and low cost off-the-shelf components. A MATLAB® based GUI is developed to control and synchronize the whole system.
Identification of Changes in Gene Expression by Quantitation of mRNA Levels

Sequence elements within mRNA-untranslated regions and their binding partners are key controllers of mRNA stability. Changes in mRNA stability can often be detected by changes in steady-state mRNA abundance, or a more careful analysis of mRNA half-lives can be performed following transcriptional repression. This chapter presents methods to isolate RNA from both yeast and mammalian cells for either steady-state or half-life analyses. In addition, two reliable methods to quantitate mRNA levels, northern blot analysis and real-time PCR, are outlined and compared.
Expression of C-Reactive Protein and Serum Amyloid A in Early to Late Manifestations of Lyme Disease

Background Infection with Borrelia burgdorferi, the causative agent of Lyme disease, triggers host immune responses that affect the clinical outcome and are a source of biomarkers with diagnostic utility. Although adaptive immunity to B. burgdorferi has been extensively characterized, considerably less information is available about the development of innate acute-phase responses in Lyme disease. Our aim in this study was to evaluate the expression of C-reactive protein (CRP) and serum amyloid A (SAA), the prototype acute-phase response proteins, in the context of the varying manifestations associated with Lyme borreliosis. Methods Circulating concentrations of CRP and SAA in patients with a range of early to late objective manifestations of Lyme disease and in individuals with post-treatment Lyme disease syndrome were compared with those in healthy control groups. Results CRP and SAA levels were significantly elevated in early localized and early disseminated Lyme disease but not in the later stages of active infection. Levels of CRP, but not SAA, were also found to be significantly increased in patients with antibiotic-refractory Lyme arthritis and in those with post-treatment Lyme disease syndrome. Conclusions These findings indicate that circulating CRP and SAA levels are highest when the concentration of spirochetes is greatest in skin and/or blood and that levels decline after the dissemination of the organism to extracutaneous sites in subsequent stages of infection. The data also suggest that antibiotic-refractory Lyme arthritis and post-treatment Lyme disease syndrome are associated with elevated CRP responses that are driven by inflammatory mechanisms distinct from those in active infection.
Developmental Mechanisms in Aging and Age-Related Diseases of the Nervous System

The mechanisms driving development of the nervous system are complex and involve the integration of many intrinsic and extrinsic signals. Many of the mechanisms which regulate development, including trophic factors, cytokines, and hormones, are the same mechanisms that dysfunction during aging and contribute to the pathogenesis of neurodegenerative disorders. A better understanding of how abnormalities in developmental signaling mechanisms may contribute to the pathogenesis of neurodegenerative disorders, and how developmental mechanisms might be tapped to restore damaged neuronal circuits are important areas for future investigations.
Band importance functions of listeners with cochlear implants using clinical maps

Band importance functions estimate the relative contribution of individual acoustic frequency bands to speech intelligibility. Previous studies of band importance in listeners with cochlear implants have used experimental maps and direct stimulation. Here, band importance was estimated for clinical maps with acoustic stimulation. Listeners with cochlear implants had band importance functions that relied more heavily on lower frequencies and showed less cross-listener consistency than in listeners with normal hearing. The intersubject variability observed here indicates that averaging band importance functions across listeners with cochlear implants, as has been done in previous studies, may not be meaningful. Additionally, band importance functions of listeners with normal hearing for vocoded speech that either did or did not simulate spread of excitation were not different from one another, suggesting that additional factors beyond spread of excitation are necessary to account for changes in band importance in listeners with cochlear implants.