cssi/SciSciGPT-SciSciNet huggingface dataset:
Model instability and channel connectivity for 2D coastal marsh simulations

Reduced freshwater inflow into a coastal marsh can result in environmental stress through episodic hypersalinity. Hydrodynamic models can be used to evaluate salinity-control strategies when freshwater supplies are constrained by climate or increasing urban demands. However, there remain significant scientific, engineering, and technical barriers to correctly modeling salinity transport in such systems. In particular, the numerical instability at the wetting/drying front caused by strong wind stress and steep surface gradient and the inappropriate representation of the complex channels at practical computational scales are unsolved problems. This study documents recent achievements in modeling the time–space evolution of shallow marsh salinity using the Fine Resolution Environmental Hydrodynamic model (Frehd) applied to the Nueces River Delta (Texas, USA). The 2D depth-integrated model is tested across a variety of bathymetric representations derived from high-resolution lidar data to evaluate the effects of grid refinement and a variety of bathymetry processing methods. Novel treatments are proposed and tested to suppress unrealistic velocities and scalar concentrations caused by rapid wetting/drying and strong wind stress. The model results are compared with the field data collected at 12 spatially-distributed locations across the marsh, yielding good model-data agreements for free surface elevation and reasonable agreements for salinity. Analyses of results indicate that the critical difficulty for capturing salinity transport is in correctly representing connectivity effects (both blocking and channel features) at fine scales on the coarse grid without overestimating fluxes. Modeled water surface elevations are relatively robust to poor representation of connectivity whereas the salinity distribution is strongly affected, particularly at key choke points. This study defines a set of future challenges in developing automated methods for evaluating and preserving geometric connectivity at practical model grid resolution.
Photocatalytic and photo-fenton activity of iron oxide-doped carbon nitride in 3D printed and LED driven photon concentrator.

Abstract We have synthesized iron oxide doped carbon nitride with 0.5 to 2 wt.% iron oxide and characterized by XPS, TGA, FTIR, SEM, photoluminescence spectroscopy and photoelectrochemical measurements. A herbicide, dicamba was employed as model organic pollutant for degradation in presence with the catalyst and hydrogen peroxide. A 3D printed photon concentrator with two chips on board (COB) LEDs with visible light spectra and two complex parabolic mirror surfaces was used as photo-reactor. The findings revealed that both photocurrent and degradation of dicamba were functions of light intensity and concentrator geometry. The rapid degradation of dicamba can be attributed to the holistic and individual actions of structural components of the photocatalyst. Four distinct phenomena, including photocatalytic activity of carbon nitride, quenching of electron/hole pairs and generation of additional reactive hydroxyl radicals by hydrogen peroxide, Fenton and photo-Fenton activity of iron oxide component of carbon nitride in presence of hydrogen peroxide and photocatalytic activity of iron oxide alone in conjuncture with carbon nitride can contribute to the overall photocatalytic activity of the system. Liquid Chromatography-Mass spectrometry (LCMS) analysis of the degradation products showed loss of chlorine from the aromatic ring and evidence of free radical addition reactions in the course of photocatalysis.
Detection of atrial fibrillation using discrete-state Markov models and Random Forests

Abstract In this paper, we present a fully automated technique for robust detection of Atrial Fibrillation (AF) episodes in single-lead electrocardiogram (ECG) signals using discrete-state Markov models and Random Forests. Methods: The ECG signal is first preprocessed using Stationary Wavelet Transforms (SWT) for noise suppression, signal quality assessment and subsequent R-peak detection. Discrete-state Markov probabilities modelling transitions between successive RR intervals along with other statistical quantities derived from the RR-interval series constitute the feature set to perform AF classification using Random Forests. Further enhancement in AF detection is achieved by using a post-processing false positive suppression algorithm based on autocorrelation analysis of the RR-interval series. Datasets: The AF classifier was trained using the Physionet/Computing in Cardiology 2017 AF Challenge dataset and the Atrial Fibrillation Termination Database (AFTDB). The test datasets consist of the MIT-BIH Atrial Fibrillation Database (AFDB) and the MIT-BIH Arrhythmia Database (MITDB). Results: Our algorithms achieved sensitivity, specificity and F-score values of 97.4%, 98.6% and 97.7% respectively on the AFDB dataset and 96.3%, 97.0% and 85.6% respectively on the MITDB dataset. It was also observed that inclusion of the false positive suppression step resulted in a 1.1% increase in specificity and a 4.0% increase in F-score for the MITDB dataset without any decrease in sensitivity. Conclusion: The proposed method of AF detection, combining Markov models and Random Forests, achieves high accuracy across multiple databases and demonstrates comparable or superior performance to several other state-of-the-art algorithms.
Surgical treatment of a giant intracranial serpentine complex aneurysm of the middle cerebral artery: Use of neuromonitoring and surgical decision tree analysis

Abstract Background Giant serpentine aneurysms are rare with only ~60 aneurysms being described in the literature. Various treatment modalities have been employed to treat these complex entities including endovascular and complex surgical methods with a range of treatment strategies including vessel sacrifice, trapping, and bypass. Complex treatment strategies are determined preoperatively with little attention given to intraoperative monitoring techniques that could affect intraoperative decision tree analysis and change operative treatment management in real time to improve outcome. Case description An elderly woman with significant comorbidities presented with an incidental, unruptured, giant serpentine middle cerebral aneurysm with associated saccular aneurysms and scheduled for open surgical approach with superficial temporal artery bypass with clipping and trapping. The presurgical plan was aborted after intraoperative neuromonitoring techniques demonstrated stable neuromonitoring functionality and bypass was aborted for simple trapping of saccular and serpentine aneurysms resulting in real-time surgical decision tree analysis. Conclusion Use of continuous neuromonitoring techniques are crucial for the real-time surgical assessment of intraoperative therapies that can affect the surgical decision tree analysis and approach to simplify surgery, limit unnecessary procedures, and improve surgical outcome.
Metabolism modulates global synchrony in the aging brain

Brain aging is associated with hypometabolism and associated global changes in functional connectivity. Using fMRI, we show that brains become globally desynchronized with age. Applying quantitative methods from statistical physics, our data identify synchrony patterns in the healthy brain to be poised at a critical point between segregating and integrating functions. We further show that aging shifts the brain away from this critical point, making it possible for marked threshold changes at the whole brain scale to arise as emergent properties of minute continuous changes in metabolism at the neuronal scale. Finally, by experimentally modulating metabolism at the neuronal scale in younger adults, we establish that this variable alone--independent of age--can provide a mechanism for global changes in synchrony.
Rural health, forensic science and justice: A perspective of planning and implementation of a sexual assault nurse examiner training program to support victims of sexual assault in rural underserved areas

Abstract The long-standing history of low or no reporting of sexual assault in rural areas, creates health disparities and justice inequity for these rural communities. In this brief perspective piece, a rural sexual assault nurse examiner (SANE) program is described in the hopes that dissemination will lead to increased numbers of rural SANEs, increased reporting of sexual assaults in rural and underserved communities, increased prosecution rates of sexual assault perpetrators, and program sustainability through the provision of a nurse-centered approach to training and support.
Evaluating higher education educators’ computer technology competencies in Libya

The purpose of this study was to evaluate issues related to the integration of technology into Libyan higher education from Libyan educators’ perspectives. A total of 161 Libyan educators who worked at the two main universities in Eastern Libya participated in the study. The study focused on four critical computer technology skill areas: (1) basic computer operation, (2) advanced computer operation, (3) use of the Internet, and (4) use of peripheral technologies. The three research objectives of the study were to (1) evaluate educators’ skill levels in four areas of computer competency, (2) investigate educators’ learning needs based on their specialty, and (3) explore educators’ teaching needs regarding types of support that allow them to improve classroom teaching. The results showed levels of perceived competency in each skill area differed significantly from perceived competence in each of the other areas. In addition, the results showed a statistically significant difference between educators who are from technical disciplines and non-technical disciplines in overall competence in using computer technologies. Furthermore, it showed that educators in technical disciplines expressed more competence in the basic and advanced computer operations. This comparison indicated a need to tailor training and implementation efforts to the needs of educators in various disciplines rather than using a standardized approach. The supplemental data using an open-ended question presented that type of support Libyan educators need to improve their teaching using computer technology. Finally, several recommendations were provided to the stakeholders in Libyan higher education.
Antioxidant studies by hydrodynamic voltammetry and DFT, quantitative analyses by HPLC-DAD of clovamide, a natural phenolic compound found in Theobroma Cacao L. beans

Clovamide (trans-clovamide, (2S)-3-(3,4-dihydroxyphenyl)-2-[[(E)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]amino]propanoic acid) is a naturally occurring caffeoyl conjugate and a potent antioxidant found in the phenolic fraction of Theobroma Cacao L. beans. This work quantified clovamide content in single-origin cocoa beans at different production stages (raw, roasted, and winnowed side and end products) by high-performance liquid chromatography with diode array detector (HPLC-DAD). We analyzed the antioxidant activities of clovamide and these extracts by measuring their superoxide radical scavenging capabilities in a Rotating Ring-Disk Electrode (RRDE) electrochemical system against in-situ generated superoxide radical. Our studies concluded a positive correlation between clovamide concentration and the overall antioxidant activities of beans, with the roasting step showing a reduction effect on both. The subsequent refining steps recover the clovamide concentration. Antioxidant studies on clovamide alone by RRDE and density functional theory (DFT) studies led to the conclusion that it is a powerful oxygen radical scavenger, partially contributed by its molecular catechol moieties.
Chapter 13 Membrane Selectivity and Ion Activities of Mammalian Tight Epithelia

Publisher Summary This chapter provides an overview of the usefulness of the intracellular voltage measurement methods, specifically microelectrode techniques, in determining epithelial transport mechanisms. Ion movement through the junctions in extremely tight epithelia is described. Ion transport is primarily modeled as a three-step process: (1) ion entry from lumen to cell, (2) movement through the cytoplasm to the basolateral membrane, and (3) extrusion from the cell to the serosal solution across the basolateral membrane. The classic model of transport in tight epithelia is that of Koefoed–Johnsen and Ussing for frog skin. The basic premise of the Koefoed–Johnsen and Ussing model that the basolateral membrane potential of epithelia is a K+ diffusion potential has been substantiated for both rabbit urinary bladder and descending colon in that the basolateral membrane potential is described by the Goldman–Hodgkin–Katz expression with the K+ activity gradient primarily determing the membrane potential. Potassium ion was found not to be in electrochemical equilibrium with the cell membrane potential, implicating an active accumulation of K+ in the cell. The coupling ratio of the Na+–K+ pump, which was originally envisaged by Koefoed–Johnsen and Ussing as 1:1, is most probably greater than 1:1.
Torture, Suicide, and Determinatio

In natural law theory, determinatio is the process by which natural law is made into determinate positive law. A lot of discussion of determinatio in natural law jurisprudence is just the repetition of tired formulas from Aquinas. In this paper, I try to bring the subject to life by considering the case that can be made for more more detailed elaboration of laws prohibiting (a) assisted suicide and (b) torture. I assume that determinatio can be a multi-step process by which we move first from a natural law ideal to a particular formulation of positive law and then from that particular positive law formulation to more precise formulations and applications. I assume also that the demand for greater and greater precision is not always healthy or wholesome in law. (a) John Finnis thinks this about the demand for more precise guidelines relating to possible prosecutions for assisted suicide in the House of Lords' last case: R. (on the application of Purdy) v DPP [2010] 1 A.C. 345. (b) I have argued elsewhere that the demand for more precise guidance concerning the application of the prohibition on torture is often vicious and unwholesome - as abusive interrogators demand a precise envelope whose boundaries they can push. In this paper, I explore why I do not agree with Finnis about (a) and why Finnis does not seem to be in wholehearted agreement with me about (b). I think that exploring these cross-cutting antagonisms casts useful light on all three topics: the law relating to assisted suicide, the law relating to torture, and the natural law idea of determinatio.
Balancing Selection in Human Evolution

Selection can act to maintain alleles within a population through many mechanisms that, taken together, constitute balancing selection. Over the course of primate and human evolution, balancing selection has repeatedly acted upon the species. Though ancient causes and effects may never be fully known or appreciated, current, ongoing, balancing selection can be observed in the human genome today. This is particularly true in genes related to immune response and pathogen defence, reproductive fitness and environmental stressors. In understanding balancing selection, it is possible to see the history of humanity's natural challenges as well as evolution's response. Keywords: balancing selection; human evolution; overdominance; MHC; human polymorphism
Looking up: Recent advances in understanding and treating peritoneal carcinomatosis

Until recently, a diagnosis of peritoneal carcinomatosis was uniformly accompanied by a grim prognosis that was typically measured in weeks to months. Consequently, the management of carcinomatosis revolves largely around palliation of symptoms such as bowel obstruction, nausea, pain, fatigue, and cachexia. A prior lack of effective treatment options created the nihilistic view that currently exists and persists despite improvements in the efficacy of systemic therapy and the evolution of multimodality approaches including surgery and intraperitoneal chemotherapy. This article reviews the evolution and current state of treatment options for patients with peritoneal carcinomatosis. In addition, it highlights recent advances in understanding the molecular biology of carcinomatosis and the focus of current and future clinical trials. Finally, this article provides practical management options for the palliation of common complications of carcinomatosis. It is hoped that the reader will recognize that carcinomatosis is no longer an imminent death sentence and that through continued research and therapeutic innovation, clinicians can make an even greater impact on this form of metastatic cancer.
Misunderstandings of atmospheric carbon budgets: Advances toward remediation of a common student misconception

With recent U.S. government efforts to develop policy procedures for addressing climate change, it is imperative that the public understand basic aspects of climate change in order for them to understand such policy. However, widespread misconceptions of basic atmospheric principles exist. In this study we document levels of misunderstanding that U.S. undergraduate students have with respect to atmospheric carbon budgets and factors that may account for variability in their understanding. Students enrolled in an introductory geology course (n = 947) completed a survey on atmospheric carbon budgets in two sequential semesters. Results indicated that most students did not have a basic understanding of mass-balance problems, and that their misunderstanding varied according to gender and their interest in science. Further, students tended to exhibit very poor graphical interpretation skills when examining mass-balance graphs. 2 Department of Geological and Atmospheric Sciences, Iowa State University. 3 Department of Statistics and Biostatistics Center, George Washington University. 4 Department of Curriculum and Instruction, Iowa State University
Construction-specific spatial information reasoning in Building Information Models

In recent years, there have been significant advances in modeling technology for object-oriented building products. However, the building models are still lacking of providing construction-specific spatial information required for construction planning. Consequently, construction planners visually analyze building product models and derive geometric characteristics such as bounded spaces and exterior perimeter to develop detailed construction plans. Such a process presents fragmented information flows, from building product information to construction planning, that rely on subjective decisions of construction planners. In order to overcome these drawbacks, this research proposes a geometric reasoning system that analyzes geometric information in building designs, derives the construction-specific spatial information, and uses the information to assist in construction planning. The scope of presented work includes detecting work packages formed by faces during construction, such as large work faces and bounded spaces, and using information in the work packages directly to support planning of selected indoor construction activities. The main features of the proposed system named Construction Spatial Information Reasoner (CSIR) include a set of relationship acquisition algorithms, building component relationship data structure, and interpretation of the relationship to support detailed construction activity planning. The relationship acquisition algorithms identify adjacency between building components that is stored in the relational data structure. Then, acquired adjacency relationships are transformed into a set of graphs that represent work packages. To implement the proposed approach, CSIR utilized a commercially-available Building Information Modeling (BIM) platform and the algorithms were imbedded to the BIM platform. For validation, CSIR was tested on a real commercial building. For interior ceiling grid installation activities, CSIR successfully detected existing work packages and analyzed the spatial characteristics impacting construction productivity. The major contribution of the presented research would be to enable a realistic analysis of building geometric condition that is not possible in current BIM and a seamless information flow from building product information to construction process plans. These can potentially reduce current manual and error-prone construction planning processes. Limitations and future research suggestions are also presented.
Toward a Model of Academic Integrity Institutionalization: Informing Practice in Postsecondary Education

The strategic choices facing higher education in confronting problems of academic misconduct need to be rethought. Using institutional theory, a model of academic integrity institutionalization is proposed that delineates four stages and a pendulum metaphor. A case study is provided to illustrate how the model can be used by postsecondary institutions as a stimulus for specifying points of change resistance and developing a common understanding of institutionalization challenges. This article bridges theory and practice in the academic integrity movement, questions assumptions about leadership of the process, and anticipates fresher approaches to examining the relationship between the teaching and research missions. Les etablissements d’enseignement superieur doivent reconsiderer leurs choix strategiques en matiere de manques a la probite intellectuelle. Cet article utilise la theorie institutionnelle pour proposer un modele d’institutionalisation de la probite intellectuelle, identiﬁ ant quatre phases et utilisant une metaphore du pendule. Une etude de cas permet d’illustrer comment le modele peut etre mis en œuvre dans les institutions d’enseignement superieur. Les resultats observes encouragent la preparation de nouvelles etudes de cas qui identiﬁ eront les sources de resistance au changement et faciliteront l’emergence d’une comprehension commune des difﬁ cultes a surmonter. L’article comble ainsi une lacune entre la theorie et la pratique au sein du mouvement pour la probite intellectuelle, interroge les presuppositions relatives au leadership de la demarche et anticipe de nouvelles approches quant a la relation entre les missions d’enseignement et de recherche.
A high frequency model for Litz wire for switch-mode magnetics

An analytical model which characterizes Litz wire over a wide frequency range is derived. The model overcomes the shortcomings of previous efforts and predicts the useful frequency range where substantial improvement over solid wire exists. Since the local proximity effects in the strands are taken into account, the degradation in performance at higher frequencies is easily predicted. The maximum useful frequency is obtained and verified by measurements. >
Biodiversity inhibits parasites: Broad evidence for the dilution effect.

Infectious diseases of humans, wildlife, and domesticated species are increasing worldwide, driving the need to understand the mechanisms that shape outbreaks. Simultaneously, human activities are drastically reducing biodiversity. These concurrent patterns have prompted repeated suggestions that biodiversity and disease are linked. For example, the dilution effect hypothesis posits that these patterns are causally related; diverse host communities inhibit the spread of parasites via several mechanisms, such as by regulating populations of susceptible hosts or interfering with parasite transmission. However, the generality of the dilution effect hypothesis remains controversial, especially for zoonotic diseases of humans. Here we provide broad evidence that host diversity inhibits parasite abundance using a meta-analysis of 202 effect sizes on 61 parasite species. The magnitude of these effects was independent of host density, study design, and type and specialization of parasites, indicating that dilution was robust across all ecological contexts examined. However, the magnitude of dilution was more closely related to the frequency, rather than density, of focal host species. Importantly, observational studies overwhelmingly documented dilution effects, and there was also significant evidence for dilution effects of zoonotic parasites of humans. Thus, dilution effects occur commonly in nature, and they may modulate human disease risk. A second analysis identified similar effects of diversity in plant–herbivore systems. Thus, although there can be exceptions, our results indicate that biodiversity generally decreases parasitism and herbivory. Consequently, anthropogenic declines in biodiversity could increase human and wildlife diseases and decrease crop and forest production.
Quantum confinement in transition metal oxide quantum wells

We report on the quantum confinement in SrTiO3 (STO) quantum wells (QWs) grown by molecular beam epitaxy. The QW structure consists of LaAlO3 (LAO) and STO layers grown on LAO substrate. Structures with different QW thicknesses ranging from two to ten unit cells were grown and characterized. Optical properties (complex dielectric function) were measured by spectroscopic ellipsometry in the range of 1.0 eV–6.0 eV at room temperature. We observed that the absorption edge was blue-shifted by approximately 0.39 eV as the STO quantum well thickness was reduced to two unit cells. This demonstrates that the energy level of the first sub-band can be controlled by the QW thickness in a complex oxide material.
Diagnostic Utility of Intracytoplasmic Lumen and Transgressing Vessels in Evaluation of Hürthle Cell Lesions by Fine-Needle Aspiration

Abstract Introduction.—Recent abstracts have emphasized the importance of recognizing intracytoplasmic lumen and transgressing vessels as useful criteria enabling distinction between Hurthle cells encountered in neoplastic and nonneoplastic thyroid aspirates. The purpose of this retrospective study was to evaluate if application of these criteria improves specificity and sensitivity of cytologic diagnosis of true Hurthle cell neoplasms. Materials and Methods.—We retrospectively reviewed 30 fine-needle aspirates of thyroid with cytologic diagnosis of Hurthle cell neoplasms (13 cases) and nonneoplastic thyroid with prominent Hurthle cells (17 cases). All cases were evaluated for the presence of intracytoplasmic lumen and transgressing vessels and were reclassified as neoplastic or nonneoplastic based on the presence or absence of 1 or both of these criteria. Surgical follow-up was available in all cases. Results.—Surgical follow-up in 13 cases of Hurthle cell neoplasms revealed Hurthle cell carcinoma (3 cas...
Protein–polysaccharide biosynthesis. Membrane-bound saccharides

Membrane-bound saccharides obtained from ear cartilage from rabbits recovering from papain injection were examined for glycosyl acceptor properties, alkali lability, molecular size and degree of sulphation. Although considerable glucuronosyl transfer from UDP-glucuronic acid could be demonstrated, less than one-third could be identified as representing chondroitin linkage formation; there was little or no effect of molecular size on acceptor properties. Approximately one-half of the membrane-associated chondroitin-like saccharide chains are solubilized by alkali, whereas one-half require proteolysis for solubilization. These fractions are analytically indistinguishable and both contain xylose and galactose as well as uronic acid and sulphated N-acetyl-galactosamine. All fragments that were examined contained stoicheiometric amounts of axial sulphate ester, strongly suggesting a close relationship between chain extension and sulphation.
Gene expression in hypothalamus and brown adipose tissue of mice divergently selected for heat loss

Allan, Mark F., Merlyn K. Nielsen, and Daniel Pomp. Gene expression in hypothalamus and brown adipose tissue of mice divergently selected for heat loss. Physiol Genomics 3: 149–156, 2000.—Gene expr...
Defining the Rural HIV Epidemic: Correlations of 3 Definitions—South Carolina, 2005-2011

Purpose To gain a better understanding of the HIV epidemic in rural South Carolina (SC) by contrasting 3 definitions of rural and urban areas. Methods The sample included newly diagnosed HIV cases aged ≥18 years in SC between January 1, 2005, and December 31, 2011. Each individual was assigned a rural or urban status as defined by the Office of Management and Budget (OMB), Census Bureau (CB), and Rural Urban Commuting Area (RUCA) classifications. Descriptive statistics were conducted to compare sociodemographic characteristics, CD4 counts, viral loads, and time to AIDS diagnosis between rural and urban populations. Kappa statistics measured the agreement between the 3 definitions of rurality. Findings Depending on the definition used, the proportion of newly diagnosed HIV cases in rural areas varied from 23.3% to 32.0%. Based on the OMB and RUCA definitions, rural residents with HIV were more likely to be older, women, black, and non-Hispanic, report heterosexual contact, and have an AIDS diagnosis within 1 year of their HIV diagnosis. The OMB and RUCA definitions had a nearly perfect agreement (kappa = 0.8614; 95% CI = 0.8457, 0.8772), while poor agreements were noted between the OMB and CB or the RUCA and CB definitions. Conclusion When examining the rural HIV epidemic, how “rural” is defined matters. Using 3 definitions of rurality, statistically significant differences were found in demographic characteristics, timing of HIV diagnosis and the proportion of rural residents diagnosed with HIV in SC. The findings suggest possible misclassification biases that may adversely influence services and resource distribution.
GTP-specific pyrophosphorylation of thiamin in dark-grown soybean (Glycine max) seedling axes

ATP:thiamin pyrophosphotransferase (TPT: EC 2.7.6.2) was purified 5 900-fold from 48 h dark-grown soybean [Glycine max (L.), Merr. cv. Ransom II] seedling axes. TPT activity was monitored during purification by measuring the formation of thiamin pyrophosphate (TPP) from [2-14C]-thiamin at optimal pH (7.3). Although other nucleoside triophosphates were active as pyrophosphate donors (apparent Kms from 21 to 138 mM), GTP was the preferred nucleotide with an apparent Km of 0.021 mM. TPT activity was extremely sensitive to TPP formation, suggesting product feedback inhibition of TPT activity in vivo. Sulfhydryl, H+ and Mg2+ concentrations, either independently or in concert, were found to affect TPT activity.
Misrepresentations of signal detection theory and a model-free approach to human image classification

Experimental methods and statistics derived from signal detection theory are frequently used to compare two imaging tech­ niques. to predict human performance under different parameteriza­ tions of an imaging system, and to distinguish variables related to human visual perception from variables related to decision making. We review recent experimental results suggesting that the assump­ tions of signal detection theory are fundamentally unsound. Instead of shifting decision criteria under different priors. humans appear to alter the information assimilation process, representing images from categories with high prior probability more accurately (less variance) than images from categories with low priorprobability. If this hypoth­ esis is correct, detection theory measures such as d' and area un­ der the receiver operating characteristic may be misleading or in­ complete. We propose an alternative approach that can be used to quantify the effects of suboptimal decision making strategies without relying on a model of detection structure. © 2001 SPIE and IS&T.
Distance estimation in virtual and real environments using bisection

Systematic error in judging distances in virtual environments is one of the most interesting problems in perceptual studies of virtual environments. The causes of this error are not known. This paper presents an experiment designed to investigate distance perception in virtual environments using the method of distance bisection (fractionation). Most other studies of distance perception in virtual environment rely on measures involving motor responses or time judgments. Unlike these, the method used in this study depends purely on visually perceived distances. Our experiment compares distance bisection judgments in virtual environments, bisection judgments in the real-world, and bisection judgments in the real-world with limited field of view. We also perform the judgments in two environmental contexts, an outdoor environment and an indoor environment. We find evidence that nonlinear distance compression occurs in virtual environments, but judgments in real-world conditions are accurate. We do not find an effect of environmental context.
Gauge theories, vertex models, and quantum groups

It is known that the Jones polynomial of knot theory, and its generalizations, are closely related to the integrable “vertex models” of two-dimensional statistical mechanics, and to quantum groups. In this paper, an attempt is made to show on a priori grounds, starting only from general covariance of three-dimensional Chern-Simons gauge theory and two-dimensional “duality”, why this must be so.
Normal unenhanced Raman spectra of CO and residual gas adsorbed on Ni(111)

Abstract Normal unenhanced Raman spectra (NURS) of low-polarizability molecules adsorbed on Ni(111) at 98 K. have been recorded at residual gas pressure. This is the first observation of Raman spectra from low-polarizability molecules adsorbed at low pressure onto a poor Raman signal enhancer. Raman bands were also recorded from Ni(111) at 98 and 298 K after exposing the crystal to 106 L CO. Assignments of CO stretches and their corresponding Ni-C stretches are discussed for both linear and bridge CO adsorbed with different neighboring species. Two low-lying vibrational modes of CO were recorded at 80 and 185 cm−1 and assigned to the CNiNi bend (on-top) and the OCNi bend (bridged), respectively. Other Raman bands are assigned to vibrations of oxygen, ozone, and hydrogen adsorbed on Ni(111).
An analysis of the population genetics of restored Zostera marina plantings in Barnegat Bay, New Jersey

Within Barnegat Bay, New Jersey, eelgrass (Zostera marina) populations have declined by 62 % over the last 20 years. To better understand the consequences of this devastation, we have previously employed microsatellite DNA polymorphisms to analyze the population structure of Z.marina within Barnegat Bay, as well as along the eastern United States seaboard. We have restored populations of Z. marina in Barnegat Bay over the last 10 years to help assess the best planting conditions and ecotypes that might be used in long-term restoration strategies. In this study, we examined the genetic health of the restored populations compared to that of the donor eelgrass populations within the bay. Using microsatellites, we can identify which parental founding ecotypes survived the restoration process over multiple generations. The frequency of observed heterozygotes, although higher than in the natural populations, still indicates reduced levels of diversity and connectivity. The inbreeding frequency is high in the restored populations, but lower than what is seen in the native populations. All restored populations have effective population values >50, suggesting a high probability of survival in the short term.
Polymerizations of Multifunctional Anhydride Monomers to Form Highly Crosslinked Degradable Networks

The synthesis of multifunctional monomers that can be photopolymerized to form highly crosslinked, surface degrading polymers is reviewed. Typical reaction behavior of multifunctional monomers is discussed, as well as the difficulties associated with photopolymerizing thicker materials and the benefits of temporal control of the photoinitiation process. Characterization of the degradation behavior of these networks indicates a surface erosion mechanism where the rate of degradation is readily controlled to produce materials that degrade on time scales of days to months. To provide insight into the structural evolution during the polymerization of multifunctional monomers, the degradation products, specifically the kinetic chain lengths, have been analyzed using MALDI-TOF spectroscopy. Additionally, the use of photopolymerizable, degrading polymers for drug delivery is illustrated, and other potential applications of these unique polymers are mentioned.
Principles for modeling propensity scores in medical research: a systematic literature review

Purpose To document which established criteria for logistic regression modeling researchers consider when using propensity scores in observational studies. Methods We performed a systematic review searching Medline and Science Citation to identify observational studies published in 2001 that addressed clinical questions using propensity score methods to adjust for treatment assignment. We abstracted aspects of propensity score model development (e.g. variable selection criteria, continuous variables included in correct functional form, interaction inclusion criteria), model discrimination and goodness of fit for 47 studies meeting inclusion criteria. Results We found few studies reporting on the propensity score model development or evaluation of model fit. Conclusions Reporting of aspects related to propensity score model development is limited and raises questions about the value of these principles in developing propensity scores from which unbiased treatment effects are estimated. Copyright © 2004 John Wiley & Sons, Ltd.
Robotic-assisted laparoscopic approach for posterior bladder neck dissection and placement of pediatric bladder neck sling: initial experience.

OBJECTIVES Bladder neck sling cystourethropexy is a common procedure used to correct intrinsic sphincter deficiency in children with spinal dyspharism. Various modifications of the procedure have been made but all involve circumferential dissection of the bladder neck and proximal urethra. The posterior dissection can be challenging and can result in injury to the rectum, urethra, or vagina. The posterior approach to the bladder neck as reported by Lottmann and later by de Badiola addresses these potential complications. Using these principles of the posterior approach, we performed a robotic-assisted laparoscopic placement of an acellular human dermal allograft bladder neck sling in 2 patients. We present our initial experience regarding this surgical technique. METHODS The diagnosis of intrinsic sphincter deficiency was established in 2 female patients, aged 9 and 10 years. Both patients had a neurogenic bladder secondary to spina bifida. Video urodynamics confirmed adequate bladder compliance and intrinsic sphincter deficiency. Robotic-assisted laparoscopic placement of a bladder neck sling was performed in both patients. RESULTS Both procedures were completed intracorporeally. The mean blood loss was 20 mL. The mean operative time was 189 minutes. No intraoperative or postoperative complications occurred. The mean hospital stay was 3 days (range 2-4). The follow-up ranged from 13 to 22 months. Postoperative studies revealed continued low-pressure, compliant bladders and stable upper tracts. At last follow-up, the 2 patients were using catheterization without difficulty and were continent. CONCLUSIONS The robotic-assisted laparoscopic approach to performing bladder neck dissection and placement of a bladder neck sling in children is technically feasible.
Finite amplitude, horizontal motion of a load symmetrically supported between isotropic hyperelastic springs

The undamped, finite amplitude horizontal motion of a load supported symmetrically between identical incompressible, isotropic hyperelastic springs, each subjected to an initial finite uniaxial static stretch, is formulated in general terms. The small amplitude motion of the load about the deformed static state is discussed; and the periodicity of the arbitrary finite amplitude motion is established for all such elastic materials for which certain conditions on the engineering stress and the strain energy function hold. The exact solution for the finite vibration of the load is then derived for the classical neo-Hookean model. The vibrational period is obtained in terms of the complete Heuman lambda-function whose properties are well-known. Dependence of the period and hence the frequency on the physical parameters of the system is investigated and the results are displayed graphically.
A reexamination of the web-based job demand for PHR and SPHR certifications in the United States

Over the past decade, the exponential growth in Professional in Human Resources (PHR) and Senior Professional in Human Resources (SPHR) certifications awarded by the Human Resource Certification Institute substantiates the need to reexamine the base rate of HR job announcements that require or prefer such certification. Based on a sample of Web-based job announcements in 2002, Aguinis, Michaelis, and Jones (2005) reported that only 1.4 percent required or preferred PHR/SPHR certification. Using a similar design, the current study found that 15.6 percent of job announcements required or preferred PHR/SPHR certification, which is nearly 11 times the rate found in the Aguinis et al. (2005) study. Results also suggested the demand for PHR/SPHR certification was positively related to experience, educational level, and job title level, with the base rate reaching 25.1 percent for managerial HR roles.
Pharmacology of 1-(3,4-dichlorobenzyl)-3,4,5,6-tetrahydro-2(1H)-pyrimidone, a novel antidepressant compound with antianxiety activity.

1-(3,4-Dichlorobenzyl)-3,4,5,6-tetrahydro-2(1H)-pyrimidone (I) was evaluated in selected pharmacological tests, and its activity was compared to that of some clinically useful psychotropic drugs. Based on the results, it is evident that I has a unique profile of antidepressant and antianxiety activities that are evident in the same dose range. The mechanism of its antidepressant activity is proposed to be similar to the tricyclic antidepressants, that is, inhibition of norepinephrine uptake. Neither I nor the tricyclic antidepressants possess monoamine oxidase-inhibiting activity. However, unlike the tricyclic antidepressants, I is devoid of any significant anticholinergic activity and presumably is free of anticholinergic side effects.
Alkenes from halides and epoxides by reductive eliminations with CrII complexes

Abstract A variety of β-substituted alkyl halides and epoxides are reductively eliminated in high yields to alkenes by CrIIen at room temperature. The reducing agent is easily prepared in situ from chromous salts and ethylenediamine. Reductive elimination and protolytic reduction of β-substituted alkyl halides by chromous reagent proceed by similar mechanisms, and involve free radicals and alkylchromium species as intermediates. In the former process, β-substituents such as hydroxy, phenoxy, acetoxy, tosyloxy, bromo, chloro, amino and trimethylammonium groups are readily eliminated from the β-substituted alkylchromium intermediate to generate alkene. Protolytic reduction of the alkylchromium species is a significant competing reaction only with such β-substituents as cyano, benzamido and phthalimido groups. Factors which determine the effect of groups on the relative rates of reductive elimination and protolytic reduction of the alkylchromium species are discussed. The formation of a free radical by an initial ligand transfer of halogen from the alkyl halide to chromous ion is enhanced by β-bromo and trimethylammonium groups. Neighboring group participation by these groups in homolytic processes to form bromine or trimethylammonium-bridged alkyl radicals as intermediates is postulated. CrIIen is a more powerful reductant than CrII and the scale of relative reactivity of various halides is compressed in the former relative to the latter. o-Diiodobenzene is reduced by CrIIen stepwise to benzene, and benzyne does not appear to be an intermediate in the reaction.
Role of Control and Social Support in Explaining the Stress of Hassles and Crowding

In a previous study, social hassles in the home, such as arguments and lack of privacy, were associated with greater psychological distress only in people living in crowded homes. Hassles were not ...
Cryptosporidium ubiquitum n. sp. in animals and humans

A new species, Cryptosporidium ubiquitum, previously identified as the Cryptosporidium cervine genotype and infrequently as the cervid, W4 or genotype 3 genotype, is described. In published studies this genotype was reported in wild and domesticated ruminants, rodents, carnivores and primates including humans. In the present study oocysts were found in feces from a captive prehensile-tailed porcupine and her infant. Oocysts from the porcupine were transmitted to 4 boer goats. Oocysts from the goats were transmitted to a calf (calf 1) and oocysts from calf 1 were transmitted to gerbils and BALB/c mouse pups. Calf 2 housed near calf 1 became contaminated and excreted oocysts of C. ubiquitum. Oocysts collected from calf 2 were transmitted to a calf 3. When calf 2 stopped excreting C. ubiquitum oocysts it was challenged with oocysts of C. parvum and became infected, indicating a lack of cross-species immunity. Oocysts of C. ubiquitum from calf 1 measured 4.71-5.32 microm x 4.33-4.98 microm (mean=5.04 microm x4.66 microm) with a length/width shape index of 1.08 (n=50). Purified PCR products of the SSU rRNA, actin and COWP genes were sequenced and analysis of the 3 unlinked loci demonstrated the new species to be distinct from all other species and also demonstrated a lack of recombination, providing further evidence of species status. Based on morphological, molecular and biological data, this geographically widespread parasite infectious for a wide range of mammalian hosts is recognized as a new species and is named C. ubiquitum.
Tomorrow's yesterday: mapping the E-Tech continuum

In computer graphics, history frames the possible, imagination paints the impossible, and passion fills in the rest.
The Electrophysiologic Time-Course of Acute Myocardial Ischemia and the Effects of Early Coronary Artery Reperfusion

Bipolar potentials were recorded from intramural electrodes located within areas of acute myocardial ischemia in dogs. Alterations in bipolar potential electromotive force (EMF) and local activation times were measured at predetermined intervals up to 12 hours after coronary occlusion. Histochemical stains were used to correlate structural-biochemical changes with sites of electrophysiologic changes. In severely ischemic areas, bipolar potentials lost 50% of their preocclusion EMF within 30 min and 95% within six hours at which time all parameters stabilized. Lesser decreases in bipolar potential EMF were recorded in the peripheral areas of the infarct. Bipolar potential EMF increased at the junction of ischemic and normal myocardium. Activation time was delayed in ischemic areas but no correlation between the magnitude of delay and the degree of tissue ischemia could be established. Coronary reperfusion after 30 min, one hr, two hr and six hr of occlusion resulted in some return in bipolar potential EMF, decreasing as a function of duration between occlusion and reperfusion. Variation in the degree of ischemia of different zones of injury within an acute myocardial infarction, as well as a different response of those zones to the return of blood flow, was shown.