cssi/SciSciGPT-SciSciNet huggingface dataset:
Helix formation and stability in membranes

Abstract In this article we review current understanding of basic principles for the folding of membrane proteins, focusing on the more abundant alpha-helical class. Membrane proteins, vital to many biological functions and implicated in numerous diseases, fold into their active conformations in the complex environment of the cell bilayer membrane. While many membrane proteins rely on the translocon and chaperone proteins to fold correctly, others can achieve their functional form in the absence of any translation apparatus or other aides. Nevertheless, the spontaneous folding process is not well understood at the molecular level. Recent findings suggest that helix fraying and loop formation may be important for overall structure, dynamics and regulation of function. Several types of membrane helices with ionizable amino acids change their topology with pH. Additionally we note that some peptides, including many that are rich in arginine, and a particular analogue of gramicidin, are able passively to translocate across cell membranes. The findings indicate that a final protein structure in a lipid-bilayer membrane is sequence-based, with lipids contributing to stability and regulation. While much progress has been made toward understanding the folding process for alpha-helical membrane proteins, it remains a work in progress. This article is part of a Special Issue entitled: Emergence of Complex Behavior in Biomembranes edited by Marjorie Longo.
Analysis for Science Librarians of the 2017 Nobel Prize in Chemistry: Cryo-electron Microscopy

The 2017 Nobel Prize in Chemistry recognized three scientists for their contributions to developing the technique of cryo-electron microscopy (cryo-EM) for the imaging and structure elucidation of ...
Counting on visitors: a review of methods and applications for the National Park Service's Visitor Use Statistics program.

The longest series of visitor use statistics for federal lands is managed by the National Park Service and goes back to 1904. The objectives of the National Park Service’s Visitor Use Statistics program are to provide statistically valid, reliable, and uniform methods of collecting and reporting visitor use data for each independently authorized unit administered by the NPS. The program addresses recreation visit counts and hours, non-recreation visit counts and hours, and overnight stays. Estimating visitor use is a complex and difficult task. The NPS estimates use at 384 park units that accommodate many different types of public access. Large iconic parks generally have entrance stations where automated vehicle counters can capture use and the NPS currently has about 960 traffic monitoring stations that employ standard vehicle counting technologies. However, there are many units where visitors enter a site in a manner where an automated counting system cannot be used. Parks with “porous” boundaries or extremely remote areas still defy reasonable visitation estimates, often because of the extreme expense involved in collecting data or conducting visitor studies. For example, urban park units such as The National Mall in Washington, D.C. and Golden Gate NRA in the San Francisco Bay area or rivers such as Niobrara NSR and Chattahoochee NRA require other approaches to estimate visitation and may include sampled counts, fixed estimates or counts with expansion multipliers. The success of the NPS Visitor Use Statistics Program is due in large part to the collaborative effort between park field staff and the national office to develop official count procedures that are consistent with NPS definitions. By providing approved options for counting and estimating visitor use, national program managers allow parks the flexibility to choose among a suite of tools that suit their unique park visitation situation. Although the initial purpose of collecting visitor use statistics for the NPS was to satisfy legal and policy mandates, the NPS and public have found a variety of other applications for these data. Data from the NPS visitor use statistics program have been used to inform NPS managers about infrastructure and capacity needs, as indicators to estimate site specific uses within a park, as a key input for visitor spending effects models, and for planning by local communities and businesses. Although the premise of collecting use statistics is to fulfill legal mandates, the utility of these data for management, planning and understanding people’s relationship to NPS managed lands highlights the value of these statistics.Subscribe to JPRA
Shopping cart interactive program (SCIP)

The Shopping Cart Interactive Program (SCIP) application was designed to improve shoppers' connection with the grocery retail environment. Nutrition is central to human life. Eating the right foods can significantly impact one's quality of life. With the capabilities of the SCIP application to provide an interface that can display readable health information on a mobile device and tailor to the specific dietary restrictions of its users, it will enable shoppers to have a less frustrating experience when shopping for food.
Formation, nutritional value, and safety of D-amino acids.

The extent of racemization of L-amino acid residues to D-isomers in food proteins increases with pH, time, and temperature. The nutritional utilization of different D-amino acids vary widely, both in animals and humans. In addition, some D-amino acids may be deleterious. For example, although D-phenylalanine is nutritionally available as a source of L-phenylalanine, high concentrations of D-tyrosine inhibit the growth of mice. The antimetabolic effect of D-tyrosine can be minimized by increasing the L-phenylalanine content of the diet. Similarly, L-cysteine has a sparing effect on L-methionine when fed to mice; however, D-cysteine does not. The wide variation in the utilization of D-amino acids is exemplified by the fact that D-lysine is not utilized as a source of L-lysine, whereas the utilization of D-methlonlne as a source of the L-isomer for growth is dose-dependent, reaching 76% of the value obtained with L-methionine. Both D-serlne and the mixture of L-L and L-D isomers of lysinoalanine induce histological changes in the rat kidneys. D-tyroslne, D-serine, and lysinoalanine are produced in significant amounts under the Influence of even short periods of alkaline treatment. Unresolved is whether the biological effects of D-amino acids vary, depending on whether they are consumed in the free state or as part of a food protein. Possible, metabolic interaction, antagonism, or synergism among D-amino acids in vivo also merits further study. The described results with mice complement related studies with other species and contribute to the understanding of nutritional and toxicological consequences of ingesting D-amino acids. Such an understanding will make it possible to devise food processing conditions to minimize or prevent the formation of undesirable D-amino acids in food proteins and to prepare better and safer foods.
A Simple Approximation Algorithm for Nonoverlapping Local Alignments (Weighted Independent Sets of Axis Parallel Rectangles)

We consider the following problem motivated by applications to nonoverlapping local alignment problems in computational molecular biology: we are a given a set of n positively weighted axis parallel rectangles such that, for each axis, the projection of a rectangle on this axis does not enclose that of another, and our goal is to select a subset of independent rectangles from the given set of rectangles of total maximum weight, where two rectangles are independent provided for each axis, the projection of one rectangle does not overlap that of another. We use the two-phase technique of [3] to provide a simple approximation algorithm for this problem that runs in O(n log n) time with a worst-case performance ratio of 3. We also discuss extension and analysis of the algorithm in d dimensions.
Survivability and Reciprocal Altruism: Two Strategies for Intelligent Infrastructure with Applications to Power Grids

While electric power grids are generally robust to small failures and thus provide a fairly high level of reliability, they are notably vulnerable to large, spectacular cascading failures. Single component failures rarely impede the ability of a power grid to serve its customers. But larger sets of concurrent outages can produce blackouts with sizes that are highly improbable from the perspective of Gaussian statistics. Because of the number of components in a power grid it is impossible to plan for and mitigate all sets of failures. Maintaining a high level of reliability in the midst of this risk is challenging. As market forces, variable sources (e.g., wind and solar power) and new loads (e.g., electric cars) increase stress on electricity infrastructure, the challenge of managing grid reliability and costs will certainly increase. Therefore we need strategies that enable the most important services that depend on electricity infrastructure to continue in the midst of risks. This chapter discusses two strategies for enabling the most important services that depend on electricity continue in the midst of significant systemic vulnerability. The first, as proposed by Talukdar et al. [26] is survivability, in which backup electricity sources provide a very high level of reliability for services that are economically and socially vital. The second, as proposed by Hines et al. [16], is Reciprocal Altruism, under which agents that manage the infrastructure are encouraged to align personal goals with those of the system as a whole.
Effect of longitudinal variation of vocal fold inner layer thickness on fluid-structure interaction during voice production

A three-dimensional fluid-structure interaction computational model was used to investigate the effect of the longitudinal variation of vocal fold inner layer thickness on voice production. The computational model coupled a finite element method based continuum vocal fold model and a Navier-Stokes equation based incompressible flow model. Four vocal fold models, one with constant layer thickness and the others with different degrees of layer thickness variation in the longitudinal direction, were studied. It was found that the varied thickness resulted in up to 24% stiffness reduction at the middle and up to 47% stiffness increase near the anterior and posterior ends of the vocal fold; however, the average stiffness was not affected. The fluid-structure interaction simulations on the four models showed that the thickness variation did not affect vibration amplitude, glottal flow rate, and the waveform related parameters. However, it increased glottal angles at the middle of the vocal fold, suggesting that vocal fold vibration amplitude was determined by the average stiffness of the vocal fold, while the glottal angle was determined by the local stiffness. The models with longitudinal variation of layer thickness consumed less energy during the vibrations compared with the constant layer thickness one.
Exercise as an intervention for patients with end-stage liver disease: Systematic review.

AbstractBackground:Various etiologies of chronic liver disease often result in cirrhosis. Beside obvious liver-related complications, cirrhosis also leads to loss of muscle mass and decreased exercise capacity. In this study, our aim was to conduct a systematic review of literature to investigate th
The Value of Systemic Unimportance: The Case of MetLife

We use an event study approach to estimate the burden of the financial regulations associated with Systemically Important Financial Institution (SIFI) designation. On March 30, 2016, the US District Court determined that MetLife’s SIFI designation was arbitrary and capricious because the Financial Stability Oversight Council (FSOC) failed to weigh the economic cost of the financial regulation on MetLife against the benefits of increased financial stability. We find significant positive abnormal returns for MetLife and AIG on the date of the ruling. We estimate that the lifting of the SIFI designation created $1.4 billion in corporate wealth for MetLife, suggesting that MetLife would be 3.4% more profitable as a non-SIFI. These gains fall short of the $8 billion stipulated by MetLife in its complaint. We also find significant abnormal returns to SIFI institutions on the day following the US Presidential election.
As Disaster Costs Rise, So Does Inequality:

Across the United States, communities are experiencing increases in the frequency and severity of natural hazards. The pervasiveness and upward trajectory of these damages are worrisome enough, but...
Machine Source Localization of Tursiops truncatus Whistle-like Sounds in a Reverberant Aquatic Environment

Most research into bottlenose dolphins9 (Tursiops truncatus9) capacity for communication has centered on tonal calls termed whistles, in particular individually-distinctive contact calls referred to as signature whistles. While "non-signature" whistles exist, and may be important components of the bottlenose dolphins9 communicative repertoire, they have not been studied extensively. This is in part due to the difficulty of attributing whistles to specific individuals, a challenge that has limited not only the study of non-signature whistles but the study of general acoustic exchanges between socializing dolphins. In this paper, we propose the first machine-learning-based approach to identifying the source locations of tonal, whistle-like sounds in a highly reverberant space, specifically a half-cylindrical dolphin pool. We feed time-of-flight and normalized cross-correlation measurements into a random forest model for high-feature-volume classification and feature selection, and subsequently feed the selected features into linear discriminant analysis, linear and quadratic SVM, and Gaussian process models. In our 14-point setup, we achieve perfect classification accuracy and high (3.22 +/- 2.63 feet) regression accuracy with less than 10,000 features, suggesting an upgrade in accuracy and computational efficiency to the whole-pool-sampling SRP-PHAT method that is the only competitive alternative at present.
Socioeconomic Distressed Communities Index associated with worse limb-related outcomes after infrainguinal bypass.

Abstract Objective Several studies have demonstrated that socioeconomic factors may affect surgical outcomes. Analyses in vascular surgery have been limited by the availability of individual or community-level socioeconomic data. We sought to determine whether the Distressed Communities Index (DCI), a composite socioeconomic ranking by ZIP code, could predict short- and long-term outcomes for patients with peripheral artery disease. Methods All Virginia Quality Initiative patients (n = 2578) undergoing infrainguinal bypass (2011-2017) within a region of 17 centers were assigned a composite DCI score. The score was developed by the Economic Innovation Group and is normally distributed from 0 (no distress) to 100 (severe distress) based on measures of community unemployment, education level, poverty rate, median income, business growth, and housing vacancies. Severely distressed communities were defined as the top quartile DCI (>75). Hierarchical regression assessed short-term outcomes, and time-to-event analyses assessed long-term results. Results Infrainguinal bypass patients in this study came from disproportionately distressed communities, with 29% of patients living within the highest distress DCI quartile (P Conclusions In this study, patients from severely distressed communities were found to have increased rates of MALEs, an association that persisted long term. Mitigating risk associated with socioeconomic determinants of health has the potential to improve outcomes for patients with peripheral artery disease.
1D phase retrieval and spectral factorization

The 1D phase retrieval problem can be solved via several optimization methods on a least-squares formulation. This provides a new algorithmic toolbox and asks for new theoretical insight.
Abstract B41: Compartment deconvolution in pancreatic cancer with biologic and clinical implications

Pancreatic ductal adenocarcinoma (PDAC) is characterized by relatively low tumor purity and an abundant tumor microenvironment. To dissect the contribution of the biologic components, we developed DECODER, which performs de novo compartment deconvolution and weight estimation of tumor samples. DECODER is a sophisticated framework that integrates runs of non-negative matrix factorization (NMF) and non-negative least square (NNLS) algorithms and can be applied to any non-negative matrices without the need to know the number of resultant factors or compartments. DECODER was used to deconvolve the TCGA pancreatic adenocarcinoma (PAAD) RNA-seq dataset, which resulted in the identification of 7 major compartments (basal tumor, classical tumor, activated stroma, normal stroma, immune, endocrine, and exocrine), confirming prior manual NMF-based solutions. These results were then used for single-sample based weight estimation in the COMPASS trial and ICGC PACA-AU RNA-seq dataset. We saw a significant positive correlation between DECODER immune weight and leukocyte fraction (r = 0.757, p Citation Format: Xianlu L. Peng, Richard A. Moffitt, Robert J. Torphy, Keith E. Volmar, Jen Jen Yeh. Compartment deconvolution in pancreatic cancer with biologic and clinical implications [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B41.
Stability of SARS-CoV-2 Phylogenies

The SARS-CoV-2 pandemic has led to unprecedented, nearly real-time genetic tracing due to the rapid community sequencing response. Researchers immediately leveraged these data to infer the evolutionary relationships among viral samples and to study key biological questions, including whether host viral genome editing and recombination are features of SARS-CoV-2 evolution. This global sequencing effort is inherently decentralized and must rely on data collected by many labs using a wide variety of molecular and bioinformatic techniques. There is thus a strong possibility that systematic errors associated with lab-specific practices affect some sequences in the repositories. We find that some recurrent mutations in reported SARS-CoV-2 genome sequences have been observed predominantly or exclusively by single labs, co-localize with commonly used primer binding sites and are more likely to affect the protein coding sequences than other similarly recurrent mutations. We show that their inclusion can affect phylogenetic inference on scales relevant to local lineage tracing, and make it appear as though there has been an excess of recurrent mutation and/or recombination among viral lineages. We suggest how samples can be screened and problematic mutations removed. We also develop tools for comparing and visualizing differences among phylogenies and we show that consistent clade- and tree-based comparisons can be made between phylogenies produced by different groups. These will facilitate evolutionary inferences and comparisons among phylogenies produced for a wide array of purposes. Building on the SARS-CoV-2 Genome Browser at UCSC, we present a toolkit to compare, analyze and combine SARS-CoV-2 phylogenies, find and remove potential sequencing errors and establish a widely shared, stable clade structure for a more accurate scientific inference and discourse.
Synthesis, Characterization, and Application of a Highly Hydrophilic Triarylmethyl Radical for Biomedical EPR

Stable tetrathiatriarylmethyl radicals have significantly contributed to the recent progress in biomedical electron paramagnetic resonance (EPR) due to their unmatched stability in biological media...
Ecological analysis of intraspecific variability of eastern white pine (Pinus strobus) under climate change by combining provenance and demographic data

Many forest tree species are composed of a gradient of populations adapted to different environmental segments, especially to temperature gradients. Therefore, populations are likely to respond differently to climate change compared to the entire species. Using Pinus strobus as an example, we model geographic patterns of growth potential and habitat suitability to understand how intraspecific genetic variation affects its response under climate change, and facilitate management. We model populations’ growth potential based on data from provenance tests and delineate three intraspecific regions: cold, middle, and warm. We predict climatic habitat suitability by modelling relative abundance for each of the intraspecific regions for current and future climates. Finally, we combine habitat suitability with growth potential and explore how combinations of these two can be used to match genotypes and climate. Suitable combinations of habitat quality and growth potential shift from the US to Canada in the future, especially under the RCP 8.5 scenario, although the Northeast states retain desirable combinations of both. The main contributors to the future abundance and productivity are populations from the middle region, followed by those from the warm region. Future suitable habitats for populations in the cold region show the most decline, supporting the need for more management of these populations. By delineating homogeneous population groups into three intraspecific regions, and considering both habitat suitability and growth potential, our analysis evaluates potential future changes for eastern white pine, including assisted migration, to facilitate better management of this commercially and ecologically important species.
A Medical Student Postpartum Telehealth Initiative During the COVID-19 Pandemic

Purpose The coronavirus disease 2019 (COVID-19) pandemic has had an unprecedented impact on our health systems and delivery of care and on the disruption of medical education. It has forced hospitals to move to a telehealth model for prenatal and postpartum visits and expedite discharges for postpartum patients in order to reduce exposure. We describe our medical school and hospital system initiative to employ medical student volunteers for postpartum telehealth calls during the peak of the COVID-19 pandemic in New York City. Description Ten medical students conducted phone interviews with postpartum patients within 72 h of discharge at three hospitals in a large NYC health system, with faculty preceptors at each site who provided daily call assignments and oversight. Students called patients to screen for risk factors for postpartum complications, including preeclampsia and postpartum depression; provide additional contraception counseling; and address newborn care and health. One week and 2 week post-discharge calls were also made for COVID-19 positive patients for ongoing symptom monitoring and counseling. Assessment We found numerous opportunities for intervention in postpartum health via telehealth, including addressing pharmacy-related needs, patient counseling, improving pain management, and identifying patients in need of emergent re-evaluation. Conclusion As this pandemic continues to evolve, our model demonstrates the feasibility of telehealth and medical student involvement in postpartum care and its benefits to patients, medical student learning, and alleviation of burden on obstetric staff.
Neurotoxic 1-deoxysphingolipids and paclitaxel-induced peripheral neuropathy

Peripheral neuropathy is a major dose-limiting side effect of paclitaxel and cisplatin chemotherapy. In the current study, we tested the involvement of a novel class of neurotoxic sphingolipids, the 1-deoxysphingolipids. 1-Deoxysphingolipids are produced when the enzyme serine palmitoyltransferase uses l-alanine instead of l-serine as its amino acid substrate. We tested whether treatment of cells with paclitaxel (250 nM, 1 µM) and cisplatin (250 nM, 1 µM) would result in elevated cellular levels of 1-deoxysphingolipids. Our results revealed that paclitaxel, but not cisplatin treatment, caused a dose-dependent elevation of 1-deoxysphingolipids levels and an increase in the message and activity of serine palmitoyltransferase (P < 0.05). We also tested whether there is an association between peripheral neuropathy symptoms [evaluated by the European Organization for Research and Treatment of Cancer (EORTC) QLQ-chemotherapy-induced peripheral neuropathy-20 (CIPN20) instrument] and the 1-deoxysphingolipid plasma levels (measured by mass spectrometry) in 27 patients with breast cancer who were treated with paclitaxel chemotherapy. Our results showed that there was an association between the incidence and severity of neuropathy and the levels of very-long-chain 1-deoxyceramides such as C24 (P < 0.05), with the strongest association being with motor neuropathy (P < 0.001). Our data from cells and from patients with breast cancer suggest that 1-deoxysphingolipids, the very-long-chain in particular, play a role as molecular intermediates of paclitaxel-induced peripheral neuropathy.
A temperature-sensitive thy mutant blocked in the synthesis of thymidylate synthetase.

thyA101 is a temperature-sensitive, thymine-requiring mutant of Escherichia coli B. At 37° it has approximately 1 to 2% of the thymidylate synthetase activity of the wild type organism. At 25° the level is about 30% of the wild type culture. These studies provide evidence that at 37° thy-101 is unable to complete the synthesis of thymidylate synthetase at the ribosomal level. On shifting a culture of thy-101 from 37° to 25°, a rapid formation of thymidylate synthetase occurs. The amount of this enzyme per unit of cell mass increases in two phases, first rapidly and then more slowly. A control enzyme such as glutamic acid dehydrogenase shows no evidence of a biphasic synthesis. Neither the rapid nor slow phase of thymidylate synthetase synthesis occurs in the presence of chloramphenicol or 5-methyltryptophan. To establish that the enzyme molecule is partially completed at 37°, thy-101 was grown at 37° in medium containing 90% deuterium oxide. The culture was then shifted to a water-containing medium at 25°. After a short period at 25°, an extract of the culture was prepared and subjected to separation by a CsCl centrifugal gradient. This procedure will separate "heavy" thymidylate synthetase of cultures grown in D2O medium from "light" thymidylate synthetase from cells grown in water medium. The presence of an intermediate enzyme band at 51% of the distance between the light and heavy bands has been taken as tentative evidence for the spontaneous formation of a light-heavy hybrid enzyme. After the shift from 37° to 25°, two major bands of thymidylate synthetase activity were found, one corresponding to light enzyme and one corresponding to heavy enzyme. From these data it was concluded that most of the thymidylate synthetase polypeptide chain had been synthesized at 37° and that the chain was completed with light amino acids at 25°. A model is presented proposing that thy-101 at nonpermissive temperatures is uniquely blocked in the synthesis of thymidylate synthetase because of an amino acid change which prevents the growing polypeptide chain from assuming the proper conformation and that this defect inhibits further movement of the ribosome.
Online learning of neural network structure from spike trains

Cascading series of events are a salient feature of neural networks, where neuron spikes may stimulate or inhibit spike activity in other neurons. Only individual spike times associated with each neuron are observed, usually without knowledge of the underlying relationships among neurons. This paper addresses the challenge of tracking how spikes within such networks stimulate or influence future events. The proposed approach is an online learning framework well-suited to streaming data, using a multivariate Hawkes point process model to encapsulate autoregressive features of observed events within the network. Recent work on online learning in dynamic environments is leveraged not only to exploit the dynamics within the underlying network, but also to track that network structure as it evolves. Regret bounds and experimental results demonstrate that the proposed method performs nearly as well as an oracle or batch algorithm.
A generalization of free-form deformation image registration within the ITK finite element framework

Since the 1970's B-splines have evolved to become the de facto standard for use in curve and surface representation. This resulted in a relatively recent proliferation of nonrigid image registration techniques based on B-splines. These techniques fall under the general Free-Form Deformation (FFD) approach in which the object to be registered is embedded within a B-spline object. The deformation of the B-spline object represents the transformation space of the registered object. In this paper, we describe the implementation of our finite element methodological (FEM) approach using B-splines. This registration framework subsumes essential components of currently popular FFD image registration algorithms, while providing a more principled and generalized control mechanism for nonrigid deformation. Our implementation constitutes an extension of the existing FEM library of the Insight Toolkit (ITK). We discuss the theoretical implications and provide experimental results of our proposed methodology.
Price Discovery from Peers

According to French and Roll (1986), the three sources of market volatility are public information, private information, and error in estimating the value of public information, which is known as “pricing error”. Even though pricing error can generate a significant amount of stock volatility and cause peculiar patterns of short-term price movement, there is little analysis on the effects of pricing error. This paper models a price discovery process that investors reduce the pricing error of a stock by consulting the prices of other stocks affected by the same information (i.e., “peer stocks”). The model shows that a stock’s pricing error and volatility are decreasing in peer stock trading activity as investors learn more from a larger peer stock price data. I test the implication of the model using NASDAQ stocks and find that higher peer stock activity is correlated with smaller pricing error and lower volatility. This learning framework is useful for understanding some empirical patterns of short-term price movement, such as high volatility in market opening prices and cross-sectional mean-reversion of stock returns.
Multivariate calibration maintenance and transfer through robust fused LASSO

This article studies calibration maintenance and transfer to build a statistical model that is able to predict analyte concentrations by a set of spectra. Noticing that the wavelength atoms are naturally ordered in a meaningful way, we propose a novel robust fused LASSO (RFL) based on high-dimensional sparsity techniques and a recent Θ-IPOD technique for robustification. This new approach can attain simultaneous wavelength selection and grouping as well as outlier identification, without any human intervention. An efficient and scalable algorithm is developed on the basis of the alternating direction method of multipliers. The obtained RFL model is sparse and shows improved prediction performance over the LASSO and ridge regression. Our results reveal that wavelengths can be combined into blocks, in a smart manner, to enhance the interpretability and reliability for super-resolution spectral analysis. Copyright © 2013 John Wiley & Sons, Ltd.
A circuit model for a family of low-voltage field-emission-array cathodes

A circuit model has been developed for a family of composite-based, low-voltage field-emitter-array cathodes. The arrays were fabricated by thin-film technology from directionally solidified oxide-metal composite materials. The typical field-emission-array contained 10/sup 7/ individual electron guns per cm2 of area. The dimensions of each electron gun is such that it operates with a cathode-extractor (cathode-gate) potential of less than 200 volts. A circuit model that predicts the performance of these emitter arrays is needed if they are to be used as electron sources in vacuum electronic devices. This work develops the requisite circuit model from the physical properties of the array, and characterizes the parameters of the circuit model using theoretical and experimental techniques.
Meeting overview: Sensory perception and schizophrenia, Lausanne, Switzerland June 31-July 1, 2014.

Abstract Schizophrenia is increasingly being viewed as a “whole brain” disorder with deficits affecting widespread cortical and subcortical networks. Within this context, studies of visual cortical function may be particularly important both because visual processing deficits directly affect social and occupational function and because these systems are well characterized at the basic science level, permitting informative translational research. This article summarizes a conference on visual processing dysfunction in schizophrenia held in Lausanne, Switzerland from June 30 to July 1, 2014 and introduces this special issue. Speakers focused on multiple aspects of visual dysfunction in schizophrenia using behavioral, neurophysiological and fMRI-based approaches. Four main themes emerged. First was a focus on response disturbances within the early visual system, using paradigms such as sensory EEG and MEG-based responses. Second, behavioral deficits were noted in processing related to local interaction within visual regions, using paradigms such as Vernier acuity or contour integration. These deficits provided potential model systems to understand impaired connectivity within the brain in schizophrenia more generally. Third, several visual measures were found to correlate highly with symptoms and/or neurocognitive processing. Deficits in contour integration, for example, correlated highly with conceptual disorganization, whereas perceptual instability correlated with delusion formation. These findings highlight links between perceptual-level disturbance and clinical manifestation. Finally, the potential involvement of specific neurotransmitter receptors, including N-methyl-D-aspartate (NMDA)-type glutamate receptors and alpha7 nicotinic receptors were discussed as potential etiological mechanisms. Overall, the meeting highlighted the contributions of visual pathway dysfunction to the etiopathogenesis of neurocognitive dysfunction in schizophrenia.
MR relaxometry for the facial ageing assessment: the preliminary study of the age dependency in the MR relaxometry parameters within the facial soft tissue

Objectives:To investigate the location-specific tissue properties and age-related changes of the facial fat and facial muscles using quantitative MRI (qMRI) analysis of longitudinal magnetization (T1) and transverse magnetization (T2) values.Methods:38 subjects (20 males and 18 females, 0.5–87 years old) were imaged with a mixed turbo-spin echo sequence at 1.5 T. T1 and T2 measurements were obtained within regions of interest in six facial fat regions including the buccal fat and subcutaneous cheek fat, four eyelid fat regions (lateral upper, medial upper, lateral lower and medial lower) and five facial muscles including the orbicularis oculi, orbicularis oris, buccinator, zygomaticus major and masseter muscles bilaterally.Results:Within the zygomaticus major muscle, age-associated T1 decreases in females and T1 increases in males were observed in later life with an increase in T2 values with age. The orbicularis oculi muscles showed lower T1 and higher T2 values compared to the masseter, orbicularis oris...
Testing the direct, indirect, and moderated effects of childhood animal cruelty on future aggressive and non‐aggressive offending

The relationship between childhood cruelty toward animals and subsequent aggressive offending was explored in 1,336 (1,154 male, 182 female) participants from the 11-wave Pathways to Desistance study (Mulvey, 2013). Aggressive and income offending at Waves 1 through 10 were regressed onto a dichotomous measure of prior involvement in animal cruelty and four control variables (age, race, sex, early onset behavior problems) assessed at Wave 0 (baseline). Results indicated that childhood animal cruelty was equally predictive of aggressive and non-aggressive (income) offending, a finding inconsistent with the hypothesis that cruelty toward animals desensitizes a person to future interpersonal aggression or in some way prepares the individual for interpersonal violence toward humans. Whereas a significant sex by animal cruelty interaction was predicted, there was no evidence that sex or any of the other demographic variables included in this study (age, race) consistently moderated the animal cruelty-subsequent offending relationship. On the other hand, two cognitive-personality measures (interpersonal hostility, callousness/unemotionality) were found to successfully mediate the animal cruelty-subsequent offending relationship. Outcomes from this study imply that a causal nexus-partially or fully mediated by hostility, callousness/unemotionality, and other cognitive-personality variables-may exist between childhood animal cruelty and subsequent offending, although the effect is not specific to violence.
Sliced-jet spectroscopy: a new technique for sub-Doppler spectroscopy of jet-cooled molecules

Abstract Direct absorption spectra of jet-cooled molecules are recorded by multipassing an infrared laser beam through a nozzle expansion and with all light rays perpendicular to the nozzle axis. A small blade is placed just upstream of the laser crossing to obstruct the passage of molecules that would otherwise absorb at the center of the Doppler profile. For the acetylene R1 line at 3300 cm -1 , the resulting holes are as narrow as 12 MHz. The 1-butyne 3333 cm -1 band is used to illustrate the technique.
Bleeding Meckel's diverticulum diagnosed by arteriography and radioisotope imaging

Preoperative demonstration of a bleeding Meckel's diverticulum represents a challenging diagnostic problem. Unfortunately, these lesions often are not detected by conventional roentgen studies. The bleeding is nearly always associated with ectopic functional gastric mucosa within the diverticulum (1), which causes ulceration of the diverticulum or adjacent ileum. The present report describes a patient with massive intestinal bleeding from a Meckel's diverticulum diagnosed preoperatively by both abdominal arteriography and radioisotope imaging with technetium pertechnetate.
Changes in L-ornithine decarboxylase activity during the cell cycle

Abstract The activity of L-ornithine decarboxylase (L-ornithine carboxy-lyase; EC 4.1.1.17), the enzyme that catalyzes the initial and rate-limiting step in polyamine biosynthesis, has been studied in Chinese hamster ovary fibroblasts synchronized by selective detachment of mitotic cells. At various times after plating the distribution of cells among the G1, S and G2+M phases of the cell cycle was calculated from DNA distributions obtained by high-speed flow cytometric analysis. At these same times determination of the cellular L-ornithine decarboxylase activity showed that polyamine (putrescine) synthesis was initiated in mid-G1, that the rate of synthesis was maximal prior to DNA synthesis, and that it decreased during the S phase. A second increase in enzyme activity occurred before mitosis.
Molecular cloning of the orphanin FQ receptor gene and differential tissue expression of splice variants in rat

Abstract Pharmacological and receptor-ligand binding studies of the cloned orphanin FQ (OFQ) receptor suggest that multiple forms of this receptor may exist. To further characterize the OFQ receptor (OFQR), we attempted to isolate the gene encoding this receptor in rat. The OFQR gene exceeds 10 kb in length and contains six exons ranging from 34 to 524 bp that are interrupted by five introns. The ATG translation initiation codon is located in exon 2, and the open reading frame consists of 1283 bp. Primer extension analysis of the gene revealed two major transcription initiation sites: one in the 5′ flanking region and the other in intron 1. The rat OFQR gene appeared to be alternatively spliced to yield multiple mRNAs. Four splice variants deleted for exon 1 were expressed only in brain. In contrast, five isoforms containing exon 1 were expressed in various tissues, such as brain, testes, and gastrointestinal tract. These data suggest that unique regions in intron 1 and in the 5′ flanking region of the OFQR gene contribute to the regulation of its expression in different tissues.
Sensitive Ground Relaying of A-C Generators [includes discussion]

Increased use has been made recently of high resistance neutral grounding of generators which operate in unit connection on high-voltage bus bars. High resistance grounding is achieved by connecting a constant resistance between the secondaries of a distribution transformer, the primaries of which are connected to the generator neutral and to ground. Replacing this resistance by one of nonlinear characteristic improves the protection by reducing the dead zone. Ground protection of the complete winding, including the neutral, may be achieved by introducing permanent neutral displacement by means of a small distribution transformer.
Visual tracking in young infants: Evidence for object identity or object permanence? ☆

Abstract Previous research has shown that 5-month-old infants visually anticipate a moving object's appearance after it disappears behind a screen. This experiment assesses the underlying basis for such anticipatory tracking. Three tracking tasks were presented to 5- and 9-month-old infants. In the Permanence task, the object's continuous existence was apparently violated while it was behind a screen. In the Feature and Trajectory tasks, the object's features or trajectory changed while behind the screen. Disruptions in the infant's smooth visual pursuit of the object were recorded. Five-mont-olds showed disruptions of visual tracking in the Feature and Trajectory tasks, but not in the Permanence task. The tracking of the 9-month-olds was disrupted in all three tasks. We conclude that both 5- and 9-month-olds possess rules specifying the identity of a moving object which is occluded. For 5-month-olds these rules are based upon the object's features and trajectory, but not upon a concept of object permanence. For 9-month-olds all three rules—feature, trajectory, and permanence—are utilized in visual tracking.
The prisoner's dilemma tournament revisited

One much-studied method for investigating trust building and cooperation is the iterative Prisoner's Dilemma Tournament (iPDT). An iPDT is easily simulated on a computer and is an excellent project in the CS1/CS2 curriculum to introduce students to the concepts of modular programming and information hiding. It is highly motivating, it encourages creative solutions, it allows students with varying abilities to do equally well, and there is no one 'ideal' solution. A software system that allows for the automatic generating of tournaments is presented in this paper, as well as information on downloading the software from the author.
Spin-coated amorphous chalcogenide films: Photoinduced effects

Abstract Photoinduced effects in spin-coated arsenic sulfide films were investigated by UV-visible spectroscopy, X-ray diffractometry, transmission electron microscopy and IR spectroscopy. Reversible effects as well as irreversible effects were observed. The photoinduced decrease in the joint density of states between the conduction and valence bands, which can be recovered by thermal annealing, is believed to be compensated by an increase in the defects in the energy gap. The decomposition, crystallization, oxidation and grain growth of the material under UV illumination were associated with the irreversible photobleaching effect.
Platinum-Loaded NaY Zeolite for Aqueous-Phase Reforming of Methanol and Ethanol to Hydrogen

Platinum-loaded NaY zeolite (Pt/NaY) catalysts were synthesized and tested for the aqueous-phase reforming (APR) of methanol and ethanol solutions to produce hydrogen. The APR performance of the Pt/NaY catalysts was compared to the conventional γ-alumina-supported platinum (Pt/γ-Al2O3) catalysts. The results have shown that the Pt/NaY catalysts have higher catalytic performance for the APR of methanol and ethanol than the Pt/γ-Al2O3 catalysts.
Theory and development of a one dimensional time dependent radiative convective climate model

Abstract A time dependent one dimensional radiative convective model (1D RCM) is developed to study the changes in the Earth's temperature that may be caused by increasing levels of CO 2 and other trace gases. Special emphasis is given to the theory and development of the model so that it may be easily used by others. The sensitivity of the Earth's surface temperature to variations in the solar constant, surface albedo, and cloud cover fraction and height is included. The model is found to predict an approximate change in surface temperature of 1.9 K for a doubling of atmospheric CO 2 (from 320 to 640 ppm). This compares favorably with other previously published results for similar models. The influence on mean global temperature of variations in the atmospheric concentrations of CO 2 , CH 4 , N 2 O, CCl 3 F, CCl 2 F 2 , and volcanic aerosols over the past century is simulated with the model. We find that this simulated temperature record compares well with the record of mean global temperature reconstructed from observations.
Light scattering by a structured particle: the homogeneous sphere with holes

To determine the effects on total light scattering of deep holes in the scattering particles, the Rayleigh-Gans-Debye and anomalous difffraction equations were solved by numerical methods for x = 0.1–1200, n = 1.05. Scattering by randomly oriented spheres with holes was compared with that from homogeneous smooth ones of equal net volume and refractive index. The effects of hole formation are found to be similar to those of projection formation that were previously reported. They also resemble those of uniform particle swelling with no change in mass. The results indicate that the influence of detail formation on total scattering is caused primarily by changes in the overall radial distribution of the mass, not by the generation of scattering centers.
Reexamination of “normal” sperm count

A males ejaculated semen can vary up to 40% in volume sperm count and sperm motivility 100 vasectomized men were studied before vasectomy for sperm counts of single specimens; 15% of these men (all fathers of 2 or more children) had sperm counts considered by accepted standards to be infertile (below 60 million). It is concluded that "fertility relativity" can exists and that there are degrees of fertility for both sexes.
An experimental study of critical heat flux in very high heat flux subcooled boiling

Abstract An experimental study of forced convective subcooled boiling heat transfer to water was performed at heat fluxes that ranged beyond 10 8 W m −2 . One of the objectives of this study was to obtain predictive ability for the critical heat flux (CHF) at high heat fluxes. Experiments were performed with metallic tubes having inside diameters ranging from 0.3 to 2.7 mm. Mass fluxes ranged from 5000 to 40 000 kg m −2 s −1 , and exit subcoolings from 40 to 135°C. Exit pressures ranged from 0.2 to 2.2 MPa, and length-to-diameter ratios ranged from 2.0 to 50.0. Single-phase and two-phase pressure drop and heat transfer data were shown to be reasonably well predicted by existing correlations. Over 200 CHF stable data points were obtained. CHF was shown to be an increasing function of both mass flux and subcooling, and an inverse function of diameter. CHF increased for length-to-diameter ratios less than 10, and decreased with increasing exit pressure. Unreasonably low CHF values were obtained for several series of tests; these premature failures are believed to be the result of thermal-hydraulic or nucleation instabilities. A ‘high flux’ CHF data base containing over 700 data points was compiled, and a new statistical correlation was developed. This correlation was tested against a recently published data base, with an average deviation of 19.4%.