cssi/SciSciGPT-SciSciNet huggingface dataset:
Salary, Performance, and Superintendent Turnover:

Purpose: Superintendent retention is an important goal for many school districts, yet the factors contributing to superintendent turnover are poorly understood. Most prior quantitative studies of s...
Determination of the migration quantity of melamine in imitation ceramic tableware by HPLC

Objective To explore the method for determining melamine migration quantity in simulation of liquid water of melamine wares by high performance liquid chromatography( HPLC) so as to provide technical means for monitoring the melamine migration quantity in melamine wares. Methods The samples of melamine tableware,which were collected from traditional markets and supermarkets,were extracted with 4% acetic acid aqueous solution for 2 h,using mixture of ion reagent( 10 mmol / L sodium 1-octanesulfonate-10 mmol / L citric acid) and acetonitrile( 85∶15,V / V) as mobile phase,and then separated with a C18column( 150 mm × 4. 6 mm,5 μm),and detected at 236. 0 nm by diode array detector to retain the qualitative time and peak area quantification. Results The melamine in the simulant liquid water of melamine tableware showed good linearity( r =0. 999 8) in the range of 0. 25 mg / L-10. 00 mg / L. The detection limit was 0. 05 mg / L,whose tagged recovery rate was between93. 9%-99. 8%,and the repeated determined relative standard deviation( RSD) were less than 1. 0%. Conclusion This method is fast,simple and accurate,which can be used to determine the migration quantity melamine in simulation of liquid water of melamine wares and is also applicable for the batch monitoring of determining melamine migration quantity in melamine wares.
Developing a Returns Competency: The Influence of Collaboration and Information Technology

In recent years, product returns have been of increasing interest to academics and managers as firms seek to maximize profits through implementing efficient supply chain management practices. Approximately 8.8 % of all retail products are returned, costing US firms billions of dollars per year. In response to the significant impact returns can have on the bottom line, firms have begun to leverage their supply chain relationships to facilitate improved management of returns and obtain an advantage over competitors. Developing a competency in product returns can be an important part of a firm’s supply chain strategy and transform returns in to a profit center by extending the productivity of materials, resources and labor. Firms like Xerox, Canon, Estee Lauder, Caterpillar, Nike, and others have all found ways to utilize returns to positively impact performance.
Studio STEM: A Model to Enhance Integrative STEM Literacy Through Engineering Design

Developing and implementing integrative curricula that enhances STEM literacy by providing meaningful connections to the lives of youth is challenging. Equally demanding is to invoke the desired cognitive, social, and affective changes that could positively influence motivation in STEM learning (Katehi, L., Pearson, G., & Feder, M. (Eds.). Engineering in K-12 education. Washington, DC: The National Academies Press, 2009). In this chapter, we present the Studio STEM model, which is comprised of theory, curricula, training, implementation, and assessment that attempts to overcome known barriers. Studio STEM is an out-of-school, design-based science and engineering program intended to engage middle school youth in critical STEM concepts and practices. The design principles that frame the model include: curricula based on science inquiry, engineering design, studio-based learning, technology-enhanced experiences and opportunities, and a focus on community connections through service organizations and businesses. The Studio STEM model addresses several issues identified by recent reports that highlight potential hindrance of full adoption of integrative STEM programming. We offer the framework by which Studio STEM was intentionally designed to be a practical program based on current theory and research. We also discuss details of what constitutes an engineering design-based science learning environment, a description of the program curricula and training, assessment measures used, and results from several implementations of Studio STEM in varying informal learning contexts (Evans et al. International Journal of Social Media and Interactive Learning Environments, 3(2), 1–31, 2014; Schnittka, C. G., Brandt, C. B., Jones, B. D., & Evans, M. A. Advances in Engineering Education, 3(2), 1–31, 2012; Schnittka et al. Looking for learning in afterschool spaces: Studio STEM (2015). Preliminary results suggest positive changes in youth engagement toward and interest in STEM as a result of participating in Studio STEM. As a result, we highlight the connections among theory and research, practical implementations of the program, and positive student and teacher outcomes related to motivation and STEM literacy driven by a focus on engineering design practices as core to these efforts.
Frequency dependent GTD coders

This paper proposes the frequency dependent generalized triangular decomposition (FDGTD) coder family for wide-sense-stationary (WSS) vector processes. Under the uniform bit allocation constraint, a set of necessary and sufficient conditions for FDGTD's coding gain optimality is derived. It is shown that one member in the FDGTD family, the frequency dependent geometric mean decomposition (FDGMD) coder, satisfies these conditions and thus is optimal. It is also demonstrated that the FDGMD coders use a simpler uniform quantizer structure and yet achieve a better performance than the conventional optimal orthonormal subband coders with sophisticated bit allocation scheme.1
Talking with the dead from southern Mexico: Tracing bioarchaeological foundations and new perspectives in Oaxaca

Abstract In recent years, bioarchaeological research has emerged as one of the principal tools for studying diverse aspects of ancient society through the analysis of human remains. Oaxaca, Mexico is a culturally diverse region of Mesoamerica that today boasts at least sixteen discrete ethnolinguistic groups. Bioarchaeology in Oaxaca has traditionally focused on the Late Formative and Classic period (500 BCE–800 CE) Zapotec city of Monte Alban, and on its hinterland. Largely descriptive, these studies provided basic discussions of health, nutrition, and funerary offerings. Beyond the Valley of Oaxaca, much less comprehensive bioarchaeological research has been undertaken to date. Never before have data from the study of human remains in multiple geographical regions and time periods within Oaxaca been assembled in a single venue. The goal of this collection of papers is to bring together the results of bioarchaeological scholarship on diverse topics, time periods, and regions. These studies investigate approximately 3500 years of precolumbian history, from the beginnings of the Early Formative (ca. 1650 BCE) to the Colonial period. The papers discuss five major geographical areas and consider various cultural groups including the Zapotec, Mixtec, Chontal, and Chatino peoples. This special issue is the first academic product of which we are aware to provide such a concentrated yet diverse consideration of the social context and bioarchaeological significance of ancient human remains from Oaxaca.
Beyond the Unfulfilled Promise of Soviet International Football, 1945–1991

After several decades of relative isolation, Soviet football (soccer) 1 made a memorable entry onto the international scene in November 1945 when the Dynamo Moscow club toured Great Britain, gaining praise from a demanding British public and press with its attractive style and dominant results. The ensuing emergence of Soviet international football occurred in the context of budding Cold War rivalries and coincided with the broader opening of Soviet society that followed the death of Joseph Stalin in March 1953. Throughout the mid-1960s, Soviet football teams continued to build on the promise of the 1945 Dynamo tour, winning a gold medal at the 1956 Melbourne Olympics, reaching the quarterfinals of the 1958 World Cup, winning the inaugural European Championship in 1960, before securing fourth place at the 1966 World Cup. Led by a world-class goalkeeper, Lev Yashin, Soviet football seemed ready to permanently join the top echelons of international football. But by the end of the Soviet period in 1991, despite a few occasional high points, a distinct feeling of underachievement and unfulfilled promise surrounded Soviet international football.
Automated Detection of Bacterial Growth for Antibiotic Susceptibility Testing

Many pathogens show highly variable in vitro antibiotic susceptibility test patterns. Availability of susceptibility results on organisms isolated from the patient is most important in assisting the clinician in selection of therapeutic agents. Unfortunately, most susceptibility testing procedures require considerable time for completion. Therefore, the choice of antimicrobial drug depends on disease symptoms, and the anticipated susceptibility pattern of organisms likely to cause such symptoms. Additionally, local susceptibility patterns are monitored to avoid prescribing drugs to which the population is resistant and to detect emergence of new resistant patterns or newly resistant strains.
Meta-analysis for medical intervention of unilateral vocal fold paralysis: Limited evidence on generalization of voice outcomes1

The purpose of the review was to complete a meta-analysis to compare the voice outcomes following silicone medialization thyroplasty (MT) versus injection laryngoplasty (IL) utilizing calcium hydro...
Alcohol Preferences and Event-Related Potentials to Alcohol Images in College Students.

Objective:Research on attentional biases to alcohol images has used heterogeneous sets of stimuli (e.g., an isolated beer can or a group of people drinking). However, alcoholic beverage preferences play an important part in determining an individual’s alcohol use pattern and may influence attentional biases, especially for inexperienced drinkers. The current study examined whether alcoholic beverage preferences affect event-related potential (ERP) indices of cue reactivity to different types of alcohol images (e.g., beer, wine, and distilled spirits) in heavy episodic drinkers.Method:ERPs were recorded in 14 heavy episodic drinkers (7 male) who completed a Go/No-Go task using preferred and nonpreferred alcohol images with nonalcoholic beverage images as controls.Results:Larger N2 amplitudes for preferred alcohol images were observed relative to control images and to nonpreferred alcohol images, indicating increased attentional capture by preferred beverages. P3 amplitudes and latencies were not sensitive ...
Applying the classroom assessment scoring system in classrooms serving students with emotional and behavioural disorders

Students with Emotional and Behavioural Disorders (EBD) have the poorest academic and social outcomes across the general and special education student populations, and are among the most likely to ...
Race, multiculturalisms and the role of science in teaching diversity: towards a critical post-modern science pedagogy

This investigation explores the role of science in teaching about diversity in schools and among pre-service teachers. Driven by the ubiquitous presence of scientific innovation and global intersec...
Panel Data Analysis of the Impact of Larger State Size/Land Area on Voter Turnout in US Presidential Elections: 2000, 2004, 2008, and 2012

This study has two objectives, both of which seek to provide insights into factors that influenced the voter participation rate in general elections in the US in recent years. The principal objective of this study is to proffer and then empirically investigate the following hypothesis: the voter participation rate of registered voters is reduced by greater state size (in squares miles) because, other things held the same, greater state size increases the transactions costs of voting for many of those persons who prefer to cast a ballot in person rather than by mail. A focus on this variable is unique in the literature. The secondary general objective of this study is to identify other factors that influenced the voter participation rate in recent years. The study adopts a state-level panel dataset and reports both Cross-section Random-effects estimations and dynamic panel estimations (Panel GMM estimates) for the first four US Presidential elections years of the 21st century, i.e., 2000, 2004, 2008, and 2012. After allowing for a variety of variables in the model, it is found that a 10,000 square mile greater size for a state in turn implies 0.148%-0.156% lower voter turnout, whereas a 100,000 square mile greater state size implies a 1.48%-1.56% lower voter turnout. Furthermore, the study finds that the voter participation rate of registered voters was an increasing function of six other factors: the unemployment rate, the percent of the population that earned a high school diploma or more, election competitiveness, median family income, and the percentage of the population that was either Afro-American/black or Hispanic/Latin.
Reprogramming Breast Cancer Cells with Embryonic Microenvironments: Insights from Nodal Signaling

Normal developmental pathways that determine cell fate, migration, and proliferative potential become reactivated in cancer to promote the most devastating aspect of the disease, namely, metastasis to new sites. However, unlike their function in the delimited process of normal growth and differentiation, developmental pathways in the context of metastatic cancer support an aberrant and unlimited morphogenic program. Understanding how specific morphogenic pathways function in normal development and how they become deregulated in cancer may provide insight into new therapeutic opportunities to limit cancer spread. Adding complexity, however, such developmental pathways do not function solely through linear, cell autonomous programs but rather as dynamic, iterative processes between cells and their microenvironment. Therefore, comprehensive strategies to treat cancer and limit recurrence and metastasis must consider the ever-changing, reciprocal developmental relationship of cancer cells with their microenvironment. One important developmental pathway that shapes the interdependent evolution of breast cancer cells and their microenvironment is signaling by the embryonic morphogen Nodal, a member of the TGF-β family and a promising, new therapeutic target. Herein we review the significance of bidirectional signaling with the microenvironment in tumor progression and the distorted recapitulation of normal developmental programs that promote tumor aggression. Further, this chapter examines the reemergence of Nodal signaling during breast cancer growth and, finally, the therapeutic potential of targeting cancer cell–microenvironment interactions in general, and particularly Nodal signaling, to reprogram these relationships and promote a more benign developmental course in malignant breast cancer.
THE SOLAR Mg II h AND k LINES – Observations and Radiative Transfer Modeling

This paper presents observations of the MgII h and k lines obtained with the UVSP instrument that flew aboard the SMM satellite. Both spatially averaged and resolved observations are compared with calculated profiles of the lines from standard, plane-parallel solar models. The radiative transfer calculations presented take full account of partial frequency redistribution and wavelength overlap of the h and k lines. A comparison between theoretical and observed wing profiles indicates that current one-dimensional models underestimate the temperature in the middle photosphere. The cores of spatially resolved dark intra-network profiles are well reproduced by the model calculations, while the spatially averaged profiles have in general broader emission peaks, indicating that the additional broadening is due to a contribution of magnetic network profiles.
Viral shedding of clade 2.3.4.4 H5 highly pathogenic avian influenza A viruses by American robins.

American robins (Turdus migratorius) are commonly associated with farmsteads in the United States and have shown previous evidence of exposure to an H5 avian influenza A virus (IAV) near a poultry production facility affected by a highly pathogenic (HP) H5 virus in Iowa, USA during 2015. We experimentally infected American robins with three clade 2.3.4.4 HP H5 viruses (H5N2 and H5N8). A total of 22/24 American robins shed virus, and all three strains were represented. The highest virus titres shed were 104.3 , 104.3 and 104.8 PFU/ml, associated respectively with viruses isolated from poultry, a captive gyrfalcon (Falco rusticolus), and a Northern pintail (Anas acuta). Of those birds that shed, viral shedding was initiated 1 or 2 days post-infection (DPI) and shedding ceased in all birds by 7 DPI. This study adds an additional synanthropic wildlife species to a growing list of animals that can successfully replicate and shed IAVs.
Sacrifice and Relational Well-Being

The well-being account of sacrifice says that sacrifices are gross losses of well-being. This account is attractive because it explains the relationship between sacrifice and moral obligation. Howe...
Errata for “Design and Analysis of a Programmable Receiver Front End Based on Baseband Analog-FIR Filtering Using an LPTV Resistor” [Jun 18 1592-1606]

A few errors were made in the above-named work that were missed during the final production phase of the paper. While the authors made IEEE aware of these errors prior to final publication, they were unfortunately left uncorrected. The errors are corrected as follows.
The Space $$\mathcal {D} '(\varOmega )$$ of Distributions

In this chapter the space of distributions is introduced and studied from the perspective of a topological vector space with various other additional features, such as the concept of support, multiplication with a smooth function, distributional derivatives, tensor product, and a partially defined convolution product. Here the nature of distributions with higher order gradients continuous or bounded is also discussed.
Long-Term Water Table Dynamics of Forested Wetlands: Drivers and their Effects on Wetland Hydrology in The Southeastern Atlantic Coastal Plain

Sustainable management of forested wetlands requires an understanding of water Table (WT) dynamics affected by rainfall and evapotranspiration (ET) and management practices, designed to sustain water quality, quantity, and ecosystem functions and productivity. In this paper analysis of long-term data from four drained and six undrained sites on coastal forested wetlands showed that their growing season WT dynamics depends upon ET as affected by vegetation stand age, with undrained sites yielding deeper WT than the drained young sites but shallower than the mature ones. Wetland hydrology criterion was not met on any of the drained sites including with controlled drainage and one unditched site with moderately well-drained sandy soil, where the WT was within 30 cm of the surface for <8% of the time compared to 31% or greater on undrained sites. WT response was similar on both drained and undrained watersheds soon after vegetation removal compared to the baseline level. Similarly, the WT dynamics on all soil types and vegetation behaved similarly during extreme storms. No trend was found in limited annual mean WT data. These results may have implications for coastal wetland forest restoration and modeling studies relating wetland hydrology as affected by anthropogenic and natural disturbances.
No effect of meal intake on physiological or perceptual responses to self-selected high intensity interval exercise (HIIE)

The present study examined the effect of meal intake on physiological and psychological indices during self-selected high intensity interval exercise (HIIE). Seventeen active men and women (age = 26.4 ± 5.8 yr) completed ramp cycle ergometry to determine maximal oxygen uptake and peak power output. On two subsequent days, they performed a session of self-selected HIIE consisting of ten 1 min bouts separated by 1 min recovery in the fed or fasted state, whose order was randomized. Meal intake consisted of a banana and a Zone™ bar containing 315 kcal, which were ingested 2 h pre-exercise, and the fasted state required no food for > 12 h pre-exercise. Participants ingested an identical meal the evening before each session. Heart rate (HR), oxygen uptake (VO2), blood glucose and blood lactate concentration, rating of perceived exertion (RPE), affect, and enjoyment were measured during exercise. Irrespective of fed state, both bouts elicited intensities equal to 94% HRmax which represents HIIE. Our results showed no difference in HR (174.0 ± 13.5 vs. 173.2 ± 12.9 b/min in fed and fasted state, p = 0.17), VO2 (2.43 ± 0.54 vs. 2.40 ± 0.52 L/min in fed and fasted state, p = 0.14), RPE (p = 0.44), affect (p = 0.79), or enjoyment (103 ± 14 vs. 101 ± 13, p = 0.77) between the fed and fasted state. Despite its high reliance on carbohydrate, performance and perception of low-volume HIIE are not altered by ingestion of a meal before exercise.
High-Speed Interrogation Approach for FBG Sensors Using a VCSEL Array Swept Source

This paper presents a fiber Bragg grating (FBG) interrogator based on vertical surface cavity emitting lasers (VCSEL). A Fabry–Perot filter technique is developed to directly calibrate the dynamic wavelength behavior of VCSELs at both low and high sweep rates. A broad bandwidth light source is constructed by multiplexing five VCSELs together to increase the number of FBGs that can be tracked. Scanning of the VCSEL-array is accomplished by a high-speed electronic switch circuit. The developed interrogator achieves a sweep bandwidth of 10 nm at a scanning rate of 4 kHz. Low-velocity impact testing of a composite plate with a surface mounted FBG sensor shows that the wavelength detection error was 2.7% when compared with the FBG strain obtained by a high-speed swept laser.
Structural stigma and all-cause mortality among sexual minorities: Differences by sexual behavior?

Abstract Using updated data from the General Social Survey/National Death Index (GSS/NDI) study, we examined whether the relationship between structural stigma—measured by aggregating 4 items assessing prejudice towards homosexuality to the community level—and all-cause mortality is present among gay men/lesbian women. Our hypothesis is based on emerging evidence that indicators of structural stigma specific to homosexuality, such as those used in the GSS/NDI, uniquely predict health outcomes among this group. Because the GSS/NDI lacked an identity-based measure of sexual orientation, we tested our hypothesis by employing a strategy that has a relatively high degree of sensitivity and specificity for ascertaining individuals most likely to identify as gay or lesbian: restricting analyses to individuals who reported same-sex sexual partners in the past year. We compared this approach against an alternative strategy, which has weaker specificity for identifying gay men/lesbian women: restricting analyses to individuals who reported any lifetime same-sex sexual behaviors. After controlling for 6 individual-level factors and fixed effects of survey year, structural stigma was associated with mortality among individuals who reported past-year same-sex sexual partners (HR = 1.95, 95% CI: 1.14, 3.31). Further, there was a dose-response relationship with mortality in this group, such that those residing in communities in the highest quartile of structural stigma had the greatest mortality risk, controlling for these same factors (HR = 2.12, 95% CI: 1.03, 4.38). In sensitivity analyses, the effect size for structural stigma ranged from 1.54 to 2.30, indicating a consistent, but small-to-moderate, effect. In contrast, no association between structural stigma and mortality was observed among respondents who reported lifetime same-sex sexual partners, nor among those reporting only opposite-sex sexual partners. This analysis therefore delimits potential boundary conditions of the association between structural stigma related to same-sex sexuality and all-cause mortality, highlighting the conditions under which this association is (and is not) observed.
A targeted assessment for prevention strategy to decrease Clostridioides difficile infections in Veterans Affairs acute-care medical centers.

Objective A guideline for the prevention of Clostridioides difficile infection (CDI) in 127 Veterans Health Administration acute-care facilities was implemented in July 2012. Beginning in 2015, a targeted assessment for prevention strategy was used to evaluate facilities for hospital-onset healthcare-facility-associated CDIs to focus prevention efforts where they might have the most impact in reaching a reduction goal of 30% nationwide. Methods We calculated standardized infection ratios (SIRs) and cumulative attributable differences (CADs) using a national data baseline. Facilities were ranked by CAD, and those with the 10 highest CAD values were targeted for periodic conference calls or a site visit from January 2016-September 2019. Results The hospital-onset healthcare-facility-associated CDI rate in the 10 facilities with the highest CADs declined 56% during the process improvement period, compared to a 44% decline in the 117 nonintervention facilities (P = .03). Conclusion Process improvement interventions targeting facilities ranked by CAD values may be an efficient strategy for decreasing CDI rates in a large healthcare system.
A Cross-sectional Study of Gender-related Differences in Reporting Fatigue and Pain among Latino/A Migrant Farmworkers.

Objectives: Migrant farmworkers face many hardships in both their working and living environments including dangerous and demanding tasks, long hours, and inadequate rest. This study sought to expl...
Chapter 3 – THE BASIC LIMIT THEOREM OF MARKOV CHAINS AND APPLICATIONS

Publisher Summary This chapter focuses on the basic limit theorem of Markov chains and applications. The chapter discusses discrete renewal equation, and proves the basic unit theorem of Markov chains. The absorption probabilities is reviewed. The chapter proves two theorems that will be useful in determining whether a given Markov chain is recurrent or transient and then they are applied to several examples. Some elementary problems are also discussed.
Centrifugally Spun α-Fe2O3/TiO2/Carbon Composite Fibers as Binder-free Anodes for Lithium Ion Batteries

In the present work, results on the electrochemical performance of flexible and binder-free α-Fe2O3/TiO2/Carbon composite fiber anodes for lithium ion batteries (LIB's) are reported. The composite fibers were produced via centrifugal spinning and subsequent thermal histories. The fibers were prepared from a precursor solution containing PVP/Iron (III) acetylacetonate/Titanium (IV) butoxide/Ethanol/Acetic acid followed by oxidation at 200°C in air and then carbonization at 550°C under flowing Argon. The morphology and structure of the composite fibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). These ternary composite-fibers anodes showed improved electrochemical performance compared to the pristine TiO2/C and α-Fe2O3/C composite fiber electrodes. The ternary α-Fe2O3/TiO2/C composite fibers also showed superior cycling performance with a specific capacity of 340 mAhg-1 after 100 cycles at a current density of 100 mAg-1 compared to 61 mAhg-1 and 121 mAhg-1 for TiO2/C, and α-Fe2O3/C composite electrodes respectively. The improved electrochemical performance and the simple processing method of these metal oxides/C composite fibers makes them promising candidates for next generation and cost-effective flexible binder-free anodes for LIBs.
Proxy Crimes and Overcriminalization

A solution to the problem of “overcriminalization” appears to be decriminalization of certain crimes. This Essay focuses on a group of crimes that has been labeled “proxy crimes” as a candidate to be eliminated. What are proxy crimes? Douglas Husak defines them as “offenses designed to achieve a purpose other than to prevent the conduct they explicitly proscribe.” Michael Moore describes them as involving situations where we “use one morally innocuous act as a proxy for another, morally wrongful act or mental state.” Put that way, proxy crimes seem highly problematic, and Larry Alexander and Kimberly Ferzan bluntly put it, “We reject proxy crimes.” This Essay asks whether we should reject proxy crimes by presenting and evaluating Alexander and Ferzan’s treatment of the subject. After describing several different types of crimes that may be characterized as proxy crimes and Alexander and Ferzan’s rejection of most of them and their arguments for doing so, this Essay argues that their rejection of proxy crimes is incomplete, which leaves their theory open to a range of possibilities regarding the proper place of proxy crimes in criminal law. This Essay concludes that getting a handle on the problem of proxy crimes and overcriminalization requires a theory of the state and an articulation of the proper relationship between the state and its citizens that can give guidance on when the state can demand obedience from citizens to support the state and when failures to comply with such demands render one criminally culpable. Without such a theory, proposals to address overcriminalization cannot travel very far.
On-Line Stabilization of Adaptive Controllers by Detuning in a Supervisory Framework

A robustness theorem concerning the on-line stabilization of an unstable control loop is given in this paper. Two controller design approaches, pole-placement and "CAMAC" are discussed. On-line stabilization can be applied when the adaptive controller operates under an intelligent supervisor.
The Role of Choledochoscopy: The Eternal Problem of How to Remove a CBD Stone.

Background. Identifying and surgically removing bile duct calculi is challenging and critical in order to provide good patient outcomes. The history of this surgical pursuit since the introduction of anesthesia is both enlightening and fascinating. Methods. A systematic review of the literature was conducted to identify the techniques and technology used to remove bile duct calculi. Results. All bile duct surgical exploration advances have involved creation of tools to look within the bile duct and extract stones. The Hopkin’s rod lens system was a major breakthrough in light and image transmission. However, flexible endoscope technology added the ability to maneuver better within the bile duct as well as apply the technology via laparoscopy enabling laparoscopic bile duct exploration. Conclusion. Digital, image enhanced, distal tipped chip flexible endoscopes have significantly improved the surgeons’ ability to see within the bile duct, improving the efficiency and ease of stone visualization and removal...
Note on Bunching of Field Lines in Black Hole Magnetospheres

Numerical simulations of Blandford-Znajek energy extraction at high spin have revealed that field lines tend to bunch near the poles of the event horizon. We show that this behavior can be derived analytically from the assumption of fixed functional dependence of current and field line rotation on magnetic flux. The argument relies crucially on the existence of the Znajek condition, which offers nontrivial information about the fields on the horizon without requiring a full force-free solution. We also provide some new analytic expressions for the parabolic field configuration.
Prenatal Care And Low-Birth-Weight Rates In Urban And Rural Wisconsin

Background: The intent of this investigation was to study the distribution of obstetric providers and prenatal care utilization in Wisconsin and analyze the potential impact of these factors on the frequency of low birth weight. Methods: State perinatal vital statistics and physician professional association surveys were used to compare the frequency of low birth weight, physician distribution, and utilization of prenatal care in all 72 counties in Wisconsin. Results: Despite higher rates of suboptimal prenatal care utilization among women residing in rural counties, low-birth-weight rates were no different. Very-Iow-birth-weight rates were actually higher for residents of urban counties compared with those in rural counties. When low birth weight was examined based on the rate of suboptimal prenatal care, a positive association was found only for urban counties. In rural counties there was no increase in low-birth-weight rates as the use of prenatal care declined. Conclusions: Inadequate prenatal care appears to be associated with low-birth-weight rates, but less so for women residing in rural counties when compared with those in urban counties.
Curriculum development for the sustainability PhD program at RIT

The typical disciplinary approach that underlies most research areas is fragmented. Consequently, advances in science and technology are often disconnected from and uninformed of the potential sustainability implications of new technologies. The PhD program in Sustainability at RIT establishes a program of study that links discipline-specific science with an understanding of the integrative sciences of sustainability, such as industrial ecology, ecological economics, risk analysis, energy policy, and ethics. Ultimately, the proposed program will transform the graduate experience by making it highly collaborative, team-based, and embedded in the broader context of economic, environmental and social understanding
Chemical speciation of trace metals at the air-sea interface: The application of an equilibrium model

Air-sea interfacial solutions have characteristically high concentrations of trace metals, microorganisms, organic compounds, and solids relative to bulk solutions. The potential for the chemical interaction of an array of trace metals in the interfacial regions with complexing organic ligands and adsorbing solid surfaces has been evaluated through the use of an equilibrium computer model. Computations suggest that higher interfacial accumulations of copper and lead may occur relative to cadmium and mercury. These results are found to be generally compatible with available field data describing trace metal interfacial accumulation. The forms of metals found to be partitioned between bulk and interfacial solutions are consistent with the hypothesis that solid surface adsorption and dissolved organic complexation reactions bring about metal enrichment at the surface microlayer.
On the functions invariant under the action of an algebraic group on an algebraic variety

LetG be an algebraic group having componentsG 1, …,G 3,V a variety, and letG operate regularly onV. The problem is to find all the rational functions onV invariant under the action ofG onV. Letk be a field of definition ofG, ofV, and of the action ofG onV. Letv be a generic point ofV/k,Gv the orbit ofv, andO (v) the closure ofGv. One defines the Chow form and reduced Chow formF ofO (v). It is proved that the quotients of the coefficients ofF generate overk the full field of invariant rational functions defined overk contained ink(v).
Cigar smoking in California: 1990–1996

Abstract Background: Cigars have been heavily promoted in recent years. The nature and extent of the resultant increase in cigar smoking needs to be understood before the public health implications can be assessed. Methods: Data are from population-based surveys conducted in California adults (≥18 years) in 1990 ( n = 24,296) and 1996 ( n = 24,266). Trends in current (every day or some days) cigar use are described for demographic subgroups and by cigarette smoking status. Results: Current cigar use has doubled in California, from 2.5% in 1990 to 4.9% in 1996. In 1996, fewer than 5% of cigar smokers smoked cigars daily; essentially all of the increase was from nondaily use in those under 45 years of age of both genders, particularly in 18- to 24-year-olds. Among males, increased cigar use was observed in all racial/ethnic groups except Asians, and was observed in those with higher educational attainment and higher incomes. In both years, current and former cigarette smokers had higher rates of cigar use than never smokers, but the increase in current cigar smoking was observed regardless of cigarette smoking status. In 1996, daily cigar smokers were more likely to be former cigarette smokers than nondaily cigar smokers. Conclusion: If more people begin to smoke cigars daily, or if cigar use leads young people to initiate cigarette smoking or leads former cigarette smokers to relapse to cigarette smoking, the recent trends in cigar use may have public health implications.
Transthoracic versus transhiatal esophagectomy: a prospective study of 945 patients.

Abstract Objective: Debate continues as to whether transhiatal esophagectomy results in lower morbidity and mortality than transthoracic esophagectomy. Most data addressing this issue are derived from single-institution studies. To investigate this question from a nationwide multicenter perspective, we used the Veterans Administration National Surgical Quality Improvement Program to prospectively analyze risk factors for morbidity and mortality in patients undergoing transthoracic esophagectomy or transhiatal esophagectomy from 1991 to 2000. Methods: Univariate and multivariate analyses were performed on 945 patients (mean age, 63 ± 10 years). There were 562 transthoracic esophagectomies and 383 transhiatal esophagectomies in 105 hospitals, with complete 30-day outcomes recorded. Results: There were no differences in recorded preoperative variables between the groups that might bias any comparisons. Overall mortality was 10.0% (56/562) for transthoracic esophagectomy and 9.9% (38/383) for transhiatal esophagectomy ( P = .983). Morbidity occurred in 47% (266/562) of patients after transthoracic esophagectomy and in 49% (188/383) of patients after transhiatal esophagectomy ( P = .596). Risk factors for mortality common to both groups included a serum albumin value of less than 3.5 g/dL, age greater than 65 years, and blood transfusion of greater than 4 units ( P P = .036). Conclusions: These data demonstrate no significant differences in preoperative variables and postoperative mortality or morbidity between transthoracic esophagectomy and transhiatal esophagectomy on the basis of a 10-year, prospective, multi-institutional, nationwide study. J Thorac Cardiovasc Surg 2003;125:1114-20
Successful emergent endovascular repair of a ruptured mycotic thoracic aortic aneurysm.

Background Mycotic thoracic aortic aneurysms are a life-threatening diagnosis and carry a high risk of morbidity and mortality in the perioperative setting. Traditional open repair consists of debridement, drainage, and either in situ or extra-anatomic bypass. Acute rupture portends a dismal prognosis; however, emergent endovascular repair of ruptured mycotic aneurysms has been described in the literature and we present a case of successful endovascular treatment of a ruptured mycotic descending thoracic aortic aneurysm. Case Report We report the case of a 42-year-old male with hypertension and active intravenous drug use who presented with 3 weeks of chest pain, dyspnea, and hemoptysis, and on computed tomography scan was found to have a contained 4.1-cm ruptured mycotic thoracic aortic aneurysm. Blood cultures were positive for methicillin-resistant Staphylococcus aureus . Emergent repair was recommended because of likelihood of further rupture and death. Thoracic endovascular aortic repair (TEVAR) was performed using a rifampin-soaked stent graft without complication. At 2-year follow-up, the patient was asymptomatic and imaging demonstrated the stent graft in excellent position, without endoleak, and complete resolution of the aneurysm sac. Conclusions TEVAR can be safely employed to treat a ruptured mycotic thoracic aneurysm when open repair is not possible because of patient's comorbidity or complex rupture, as these patients face imminent death. Long-term follow-up is necessary for detection of endoleak, recurrence, or propagation of the aneurysm, and persistent bacterial infections.
Retheorizing Sexual Harassment in Medical Education: Women Students' Perceptions at Five U.S. Medical Schools

Abstract Background: The literature consistently reports that sexual harassment occurs with regularity in medical education, mostly in clinical settings, and most of it goes unreported. Reasons for nonreporting include the fear of retaliation, a reluctance to be viewed as a victim, a fear that one is being “too sensitive,” and the belief that nothing will be done. Purpose: We wanted to examine with greater concentration the stories women students tell about sexual harassment, including what they count as sexual harassment, for more or different clues to their persistent nonreporting. Methods: We used focus groups to interview 30 women students at 5 U.S. medical schools. We used systematic inductive guidelines to analyze the transcribed data, linking to and building new theoretical frameworks to provide an interpretive understanding of the lived experiences of the women in our study. Results: Consistent with previous literature, most of the students interviewed had either witnessed or observed sexual haras...
Obesity and Screening PSA Levels Among Men Undergoing an Annual Physical Exam

BACKGROUND Prior reports suggest that obesity is inversely associated with screening prostate-specific antigen (PSA) levels and may reduce screening sensitivity. METHODS We evaluated data on 10,623 men screened for prostate cancer during an annual physical examination program administered by EHE International, Inc., between 1/1/2004 and 6/30/2006. Of these, 3,623 men returned for additional physical exams during this period. We used multivariate linear regression analyses to determine whether higher BMI was inversely associated with PSA, and whether BMI, or change in BMI, was associated with change in PSA levels over time. We also developed a theoretical model for the effect of obesity on PSA levels in which increased plasma volume in the obese dilutes PSA levels. RESULTS After control for age and race/ethnicity, higher BMI was associated with lower PSA levels; men with a BMI ≥40 had a geometric mean PSA level 0.14 ng/ml lower than men with a BMI <25 (P < 0.001). Prospectively, BMI at initial screening and change in BMI over 2 years were not associated with change in PSA or PSA velocity. Our theoretical model accurately predicted observed PSA levels and suggests that a screening PSA of 4.0 ng/ml in normal weight and overweight men corresponds to 3.5 ng/ml in obese men and 3.1 ng/ml in morbidly obese men. CONCLUSION Across the study population, increased BMI was significantly inversely associated with lower PSA. Based on a theoretical model in which increased plasma volume in the obese dilutes PSA levels we propose new cut-points for a positive screening test. Prostate 68: 373–380, 2008. © 2008 Wiley-Liss, Inc.
Ultralow threshold current vertical-cavity surface-emitting lasers obtained with selective oxidation

The authors report InGaAs single quantum well vertical-cavity surface-emitting lasers with an intracavity p-contact fabricated by selective oxidation of AlAs and distributed Bragg reflectors composed of binary materials (AlAs/GaAs). Record low threshold currents of 8.7 µA in ~3 µm square devices and 140 µA in 10 µm square devices with maximum output powers over 1.2 mW are achieved.
Decentralized Opportunistic Navigation Strategies for Multi-agent Systems in the Presence of an Adversary

Abstract We investigate a jamming attack on the communication network of a multi-agent system in a formation. We propose a communication and motion model for the agents. The communication model provides a relation in the spatial domain for effective jamming by an intruder. We formulate the problem as a zero-sum pursuit-evasion game. In our earlier work we used Isaacs’ approach to obtain motion strategies for a network of agents to evade the jamming attack. In this work, we imagine a scenario in which each agent has a knowledge about the value function under perfect state information, beforehand. Due to lack of information about all the agents in the team each agent is constrained to make a local decision based on the information about his neighbors. We propose on-line algorithms under decentralized information patterns which converge for each player. We propose approximation algorithms for the agents, based on averaging and provide some bounds on their performance.
A specific CpG methylation pattern of the MGMT promoter region associated with reduced MGMT expression in primary colorectal cancers

The enzyme O6-methylguanine-DNA methyltransferase (MGMT) protects cells from the cytotoxic and mutagenic effects of alkylating agents. Approximately 20% of tumor cell lines lack MGMT activity and are highly sensitive to alkylating agents. In established cancer cell lines, MGMT expression appears to be correlated with methylation of residues in both the promoter and the body of the gene. The effect of methylation of the MGMT promoter on gene expression and carcinogenesis in primary tumors is unknown. We investigated methylation of the MGMT promoter region in primary colorectal cancers and normal colonic mucosa. We used five methylation-sensitive restriction enzymes (BssHII, SacII, Eagl, Nael, and Smal) and Southern blot analysis to assess methylation in 46 cancers and 22 controls. Methylation of Eagl and Nael sites was seen in 12 tumors but in none of the 22 normal colorectal mucosa specimens. This difference was statistically significant (P<0.01). Methylation-sensitive single-nucleotide primer extension analysis of four additional cytosine residues confirmed methylation of the promoter region in the tumors identified by Eagl and Nael digestions and served to further quantitate the extent of methylation. Western blot analysis of 21 tumors revealed statistically significant lower MGMT expression in the eight tumors with methylation of the Eagl and Nael sites and nt -128 than in the 13 tumors lacking the methylation pattern (P<0.05). MGMT activity was lower in tumors with methylation than in tumors that were not methylated. The difference was not, however, statistically significant. We conclude that a subset of colorectal tumors is characterized by a specific methylation pattern in the MGMT promoter associated with reduced MGMT expression.
Prolonged sleep fragmentation of mice exacerbates febrile responses to lipopolysaccharide

Background Sleep disruption is a frequent occurrence in modern society. Whereas many studies have focused on the consequences of total sleep deprivation, few have investigated the condition of sleep disruption.
FOUR WORTHWHILE SOFTWARE PRODUCTS

There are several new or revised software products that I want to talk about in this column. I've found them to be worth the time and expense and think you might, too. The first is Ami Pro Version 2.0 which is a graphical word processor that permits you to do sophisticated desktop publishing. The second is Quattro Pro 4.0 the latest upgrade to the now venerable Quattro spreadsheet series. The third product is Stacker, a data compression utility that can more than double your hard disk storage space. Finally, there is Windows 3 Secrets which is a book with two disks of software. (As an aside, what kind of “ware” is a book—paperware?)
COMPARING THE LIFE CONCERNS OF PRESCRIPTION OPIOID AND HEROIN USERS

Abstract This study explored life concerns of prescription opioid (PO) and heroin users. Persons entering opioid detoxification rated their level of concern about 43 health and welfare items. Using exploratory factor analysis and conceptual rationale, we identified ten areas of concern. Participants ( N =529) were 69.9% male, 87.5% non-Hispanic Caucasian, and 24.2% PO users. Concern about drug problems was perceived as the most serious concern, followed by money problems, relationship problems, mental health, and cigarette smoking. PO users expressed significantly lower concern about drug problems ( p =.017) and transmissible diseases ( p p