cssi/SciSciGPT-SciSciNet huggingface dataset:
Benzodiazepines and risk of all cause mortality in adults: cohort study.

Objectives To evaluate the risk of all cause mortality associated with initiating compared with not initiating benzodiazepines in adults, and to address potential treatment barriers and confounding related to the use of a non-active comparator group. Design Retrospective cohort study. Setting Large de-identified US commercial healthcare database (Optum Clinformatics Datamart). Participants 1:1 high dimensional propensity score matched cohort of benzodiazepine initiators, and randomly selected benzodiazepine non-initiators with a medical visit within 14 days of the start of benzodiazepine treatment (n=1 252 988), between July 2004 and December 2013. To address treatment barriers and confounding, patients were required to have filled one or more prescriptions for any medication in the 90 days and 91-180 days before the index date (ie, the date of starting benzodiazepine treatment for initiators and the date of the selected medical visit for benzodiazepine non-initiators) and the high dimensional propensity score was estimated on the basis of more than 300 covariates. Main outcome measure All cause mortality, determined by linkage with the Social Security Administration Death Master File. Results Over a six month follow-up period, 5061 and 4691 deaths occurred among high dimensional propensity score matched benzodiazepine initiators versus non-initiators (9.3 v 9.4 events per 1000 person years; hazard ratio 1.00, 95% confidence interval 0.96 to 1.04). A 4% (95% confidence interval 1% to 8%) to 9% (2% to 7%) increase in mortality risk was observed associated with the start of benzodiazepine treatment for follow-ups of 12 and 48 months and in subgroups of younger patients and patients initiating short acting agents. In secondary analyses comparing 1:1 high dimensional propensity score matched patients initiating benzodiazepines with an active comparator, ie, patients starting treatment with selective serotonin reuptake inhibitor antidepressants, benzodiazepine use was associated with a 9% (95% confidence interval 3% to 16%) increased risk. Conclusions This large population based cohort study suggests either no increase or at most a minor increase in risk of all cause mortality associated with benzodiazepine initiation. If a detrimental effect exists, it is likely to be much smaller than previously stated and to have uncertain clinical relevance. Residual confounding likely explains at least part of the small increase in mortality risk observed in selected analyses.
Drugs and Behavior, Psychiatry of

The mid-twentieth century began a revolution in the pharmacologic treatment of mental disorder. Barbiturates and benzodiazepines allowed treatment of anxiety disorders. Phenothiazines revolutionized the treatment of schizophrenia. Antidepressants provided relief from disabling states of depression. Bipolar disorder became amenable to treatment. Psychostimulants relieved attention-deficit/hyperactivity disorder and other disorders of attention, thought, and memory. The disabling effects of Parkinson's disease were alleviated; and new anesthetic agents allowed for the provision of safe anesthesia for patients in any state of health, or disability. At the beginning of the twenty-first century the search for even better therapeutic agents continues. Beyond this, psychopharmacology has provided tools with which we can explore the basis of neuronal dysfunction in mental disease. More specifically, molecular psychopharmacology explores the intra-neuronal and genetic influences involved in drug action and in disease. Today, targets of drug therapy are not only specific synaptic neurotransmitters and receptors, but also the genetics that underlie the transcriptional processes that may be dysfunction in certain disease states. As examples, this article delineates our newfound knowledge of the mechanisms of action of antidepressants, and the pharmacology of tetrahydrocannabinol.
Flattened Hierarchy Through Drama-Based Pedagogy: A Graduate Student Instructor and Two Undergraduates Partner on Classroom Research

ABSTRACTIn this paper, the authors describe their journey from a teacher-student relationship to that of research partners and co-authors, thus providing a case study situated within the literature on students as partners. The instructor's use of drama-based pedagogy organically facilitated this journey both by flattening the hierarchy between teacher and students, and by being the subject under study. As a research group, the authors designed and collaborated on a scholarship of teaching and learning (SoTL) project. They analyzed existing classroom data to study the effects of drama-based pedagogy on their classroom environment and presented findings at conferences and through publication. This collaboration between a graduate student instructor and her undergraduate learners benefited all parties from both research and professionalization perspectives, which mirrors positive outcomes in the students as partners literature. The partnership can thus serve as a model for similar partnerships with minimal i...
Conversion of spin current into charge current in a topological insulator: Role of the interface

Three-dimensional spin current density injected onto the surface of a topological insulator (TI) produces a two-dimensional charge current density on the surface of the TI, which is the so-called inverse Edelstein effect (IEE). The ratio of the surface charge current density on the TI to the spin current density injected across the interface defined as the IEE length was shown to be exactly equal to the mean free path in the TI determined to be independent of the electron transmission rate across the interface [Phys. Rev. B 94, 184423 (2016)]. However, we find that the transmission rate across the interface gives a nonzero contribution to the transport relaxation rate in the TI as well as to the effective IEE relaxation rate (over and above any surface hybridization effects), and the IEE length is always less than the original mean free path in the TI without the interface. We show that both the IEE relaxation time and the transport relaxation time in the TI are modified by the interface transmission time. The correction becomes significant when the transmission time across the interface becomes comparable to or less than the original momentum scattering time in the TI. This correction is similar to experimental results in Rashba electron systems in which the IEE relaxation time was found shorter in the case of direct interface with metal in which the interface transmission rate will be much higher, compared to interfaces incorporating insulating oxides. Our results indicate the continued importance of the interface to obtain a better spin-to-charge current conversion and a limitation to the conversion efficiency due to the quality of the interface.
A New Fast Heuristic for Computing the Breakpoint Phylogeny and Experimental Phylogenetic Analyses of Real and Synthetic Data

The breakpoint phylogeny is an optimization problem proposed by Blanchette et al. for reconstructing evolutionary trees from gene order data. These same authors also developed and implemented BPAnalysis [3], a heuristic method (based upon solving many instances of the travelling salesman problem) for estimating the breakpoint phylogeny. We present a new heuristic for this purpose; although not polynomial-time, our heuristic is much faster in practice than BPAnalysis. We present and discuss the results of experimentation on synthetic datasets and on the flowering plant family Campanulaceae with three methods: our new method, BPAnalysis, and the neighbor-joining method [25] using several distance estimation techniques. Our preliminary results indicate that, on datasets with slow evolutionary rates and large numbers of genes in comparison with the number of taxa (genomes), all methods recover quite accurate reconstructions of the true evolutionary history (although BPAnalysis is too slow to be practical), but that on datasets where the rate of evolution is high relative to the number of genes, the accuracy of all three methods is poor.
Assembly and secretion of the lipid globules of milk.

While the structure, biosynthesis, processing, and nutritional characteristics of milk lipids have been studied extensively, remarkably little is known about the intracellular formation of triacylglycerol-rich droplets destined to be secreted as milk lipid globules. That lipid droplets are secreted from cells by progressive envelopment in plasma membrane has been recognized since the pioneering electron microscope study of Bargmann and Knoop (1959); but what molecules and forces are involved in this secretory process remains a matter of speculation. That there has been little study of the lipid globule secretion mechanism is surprising for a number of reasons: This secretion mechanism involves large losses of differentiated regions of plasma membrane from the cell; this membrane can be obtained readily for study; the cells must have an efficient mechanism for replenishment of the secreted plasma membrane. This lipid secretory mechanism may be unique to mammary epithelial cells, as this pathway has not been described for any other cell type. There are striking parallels between lipid droplet secretion and the release of enveloped viruses from cells(reviews, Patton & Keenan 1975; Mather & Keenan 1983; Keenan et al. 1988). Of the several reasons that can explain this lack of study, two emerge as primary. One is that many of the agencies providing support for studies of milk have had ultimate commercial utilization as their overriding interest. Fundamental biological questions regarding the origin of milk lipid globules have not been within this sphere of interest. Second.
Cybercrime and the Law

The proliferation of cybercrime, combined with the tragic events of September 11, 2001, has placed a premium on security, both from crime and from terrorism. At the same time, it has raised important issues concerning privacy.
Catalytic Dehydrogenation of Cyclohexane Using Coated Silica Oxide Ceramic Membranes

Experiments were conducted to characterize US Filter ceramic membranes used in the catalytic dehydrogenation of cyclohexane to benzene. The reaction yield was studied as a function of membrane pore size for 50, 100, 200, and 2000 A membranes. The effect on reaction yield, membrane permeability, and membrane selectivity of altering pore size by addition of successive thin film layers (silica oxide particles in an iron(III) supported solution) to the membrane surfaces was the primary focus of the study. The membranes were also characterized with a nonreactive He/N2 separation to determine the effect of successive thin film layers on the extent of Knudsen diffusion as the transport mechanism. This characterization demonstrated that Knudsen behavior could be obtained in a large pore diameter membrane by adding thin film layers to the surface. Reaction experiments showed a 300% increase in yield from that which was obtained in an impermeable reactor under similar conditions. Most significantly, the coated membranes operating in the Knudsen regime rendered a higher reaction yield than the uncoated 50 A membrane, whose transport mechanism was also Knudsen dominated. This phenomena can be explained by favorable surface effects between the thin film material and the reaction species. Thus, it was concluded, that a thin film (added to the surface membrane), which operates in the Knudsen regime and creates favorable surface effects to enhance membrane selectivity, can shift reaction equilibrium to a higher product yield than a membrane which only exhibits Knudsen diffusion.
How Success Versus Failure Cases Support Knowledge Construction in Collaborative Problem-Solving:

Theorists suggest that collaboration is a key aspect in online, inquiry-based learning. However, research finds that meaningful interaction is challenging, and learners struggle to sustain interact...
Product Attribute Forecast: Adaptive Model Selection Using Real-Time Machine Learning

Abstract A real-time machine learning framework is developed to forecast product concentration in mammalian cell culture bioreactors. In real-time, the framework evaluates several machine learning algorithms and chooses the most representative algorithm based on current dynamics of the system. Data from multiple sources is combined and only subset of features are fed to the model based on a pre-selection criteria. The model performance is tested using two small-scale bioreactors run. The performance improved towards the end of the process with accumulating data and results for 1 day ahead prediction is presented.
Metabolic Basis for Mutualism between Gut Bacteria and Its Impact on the Drosophila melanogaster Host

ABSTRACT Interactions between species shape the formation and function of microbial communities. In the gut microbiota of animals, cross-feeding of metabolites between microbes can enhance colonization and influence host physiology. We examined a mutually beneficial interaction between two bacteria isolated from the gut microbiota of Drosophila, i.e., Acetobacter fabarum and Lactobacillus brevis. After developing an in vitro coculture assay, we utilized a genetic screen to identify A. fabarum genes required for enhanced growth with L. brevis. The screen, and subsequent genetic analyses, showed that the gene encoding pyruvate phosphate dikinase (ppdK) is required for A. fabarum to benefit fully from coculture. By testing strains with mutations in a range of metabolic genes, we provide evidence that A. fabarum can utilize multiple fermentation products of L. brevis. Mutualism between the bacteria in vivo affects gnotobiotic Drosophila melanogaster; flies associated with A. fabarum and L. brevis showed >1,000-fold increases in bacterial cell density and significantly lower triglyceride storage than monocolonized flies. Mutation of ppdK decreased A. fabarum density in flies cocolonized with L. brevis, consistent with the model in which Acetobacter employs gluconeogenesis to assimilate Lactobacillus fermentation products as a source of carbon in vivo. We propose that cross-feeding between these groups is a common feature of microbiota in Drosophila. IMPORTANCE The digestive tracts of animals are home to a community of microorganisms, the gut microbiota, which affects the growth, development, and health of the host. Interactions among microbes in this inner ecosystem can influence which species colonize the gut and can lead to changes in host physiology. We investigated a mutually beneficial interaction between two bacterial species from the gut microbiota of fruit flies. By coculturing the bacteria in vitro, we were able to identify a metabolic gene required for the bacteria to grow better together than they do separately. Our data suggest that one species consumes the waste products of the other, leading to greater productivity of the microbial community and modifying the nutrients available to the host. This study provides a starting point for investigating how these and other bacteria mutually benefit by sharing metabolites and for determining the impact of mutualism on host health.
Infrared Reflection – Absorption Spectrometry of Monolayer Films at the Air – Water Interface

The sections in this article are Introduction Experimental Instrument Design Water Vapor Compensation Experimental Caveats Interpretation of Experimental Data Frequencies Intensities Determination of Tilt Angles by IRRAS Definitions of Optical Parameters The Fresnel Equations for Reflection Modifications for Anisotropic Molecular Orientation Computer Simulations Determination of Helix Orientation21 Applications of IRRAS Future Prospects Acknowledgment
Making Mathematical Notation More Meaningful.

which states that the average of a set with members, Xu X2, X3, . . . , Xn, is the sum of all its members divided by n. If we assume students can add and divide, then the ability of students to learn how to compute an average depends largely on their ability to decipher the meanings of all the symbols in (1). I believe there are some rules that can simplify the task of communicating mathematical ideas with symbols. For example, to simplify (1), two appropriate rules are the following: symbols should be familiar (out with sig ma), and symbols should be mnemonics (in with SUM). Another notational rule is the following: a notation should promote generalization. This suggests the follow ing scheme appropriate for the computer age.
Does fracking drive you to drink? Unconventional oil and gas production and alcohol consumption in U.S. counties

Abstract Unconventional drilling technologies like hydraulic fracturing and directional drilling have markedly increased oil and gas production in the United States while also bringing production in proximity with many communities. Foundational research in rural sociology predicts the rise of local “boomtown” problems like excessive alcohol consumption as a result of sudden energy booms. In this paper, we use data from U.S. counties to understand the relationship between energy production and alcohol consumption. Results suggest that oil and gas production has very modest effects on binge drinking and heavy drinking, and that these effects may vary by gender and across U.S. states.
On the convergence of higher-order orthogonal iteration

The higher-order orthogonal iteration (HOOI) has been popularly used for finding a best low-multilinear rank approximation of a tensor. However, its convergence is still an open question. In this paper, we first analyse a greedy HOOI, which updates each factor matrix by selecting from the best candidates one that is closest to the current iterate. Assuming the existence of a block-nondegenerate cluster point, we establish its global iterate sequence convergence through the so-called Kurdyka–ᴌojasiewicz property. In addition, we show that if the starting point is sufficiently close to any block-nondegenerate globally optimal solution, the greedy HOOI produces an iterate sequence convergent to a globally optimal solution. Relating the iterate sequence by the original HOOI to that by the greedy HOOI, we then show that the original HOOI has global convergence on the multilinear subspace sequence and thus positively address the open question.
Do Constructs in Organizational Behavior Predict Job Performance over Job Satisfaction

Over the last decades, many new constructs have been proposed in the field of organizational behavior (OB). While these constructs have certainly advanced our understanding of various organizationa...
Head-Mounted Display Use in Surgery: A Systematic Review

Purpose. We analyzed the literature to determine (1) the surgically relevant applications for which head-mounted display (HMD) use is reported; (2) the types of HMD most commonly reported; and (3) the surgical specialties in which HMD use is reported. Methods. The PubMed, Embase, Cochrane Library, and Web of Science databases were searched through August 27, 2017, for publications describing HMD use during surgically relevant applications. We identified 120 relevant English-language, non-opinion publications for inclusion. HMD types were categorized as "heads-up" (nontransparent HMD display and direct visualization of the real environment), "see-through" (visualization of the HMD display overlaid on the real environment), or "non-see-through" (visualization of only the nontransparent HMD display). Results. HMDs were used for image guidance and augmented reality (70 publications), data display (63 publications), communication (34 publications), and education/training (18 publications). See-through HMDs were described in 55 publications, heads-up HMDs in 41 publications, and non-see-through HMDs in 27 publications. Google Glass, a see-through HMD, was the most frequently used model, reported in 32 publications. The specialties with the highest frequency of published HMD use were urology (20 publications), neurosurgery (17 publications), and unspecified surgical specialty (20 publications). Conclusion. Image guidance and augmented reality were the most commonly reported applications for which HMDs were used. See-through HMDs were the most commonly reported type used in surgically relevant applications. Urology and neurosurgery were the specialties with greatest published HMD use.
Working with African-American Families in the Perinatal Period and Early Childhood

This chapter underscores the variations in beliefs and practices that might be considered as “African-American” and the pitfalls of generalizations and unwarranted assumptions. It addresses the question of slavery, emancipation, and the possible transgenerational effects. There is still widespread prejudice against African-American persons, as well as segregation and injustices in the legal and educational systems, for instance. There is a higher prevalence of poverty compared with Caucasian families. This is associated with more adverse perinatal outcomes, lower prevalence of breastfeeding, and of psychosocial stress for families. At the same time, there are resilient features such as reliance on family members, community networks, churches, and strong sibling relationships that help families solve problems and thrive. In a climate of segregation and higher psychosocial risk, parents, grandparents, and extended relatives contribute to raise young children and support young parents. Issues like the skin tone, physical properties of the infant’s hair, and being strong are often issues that make a difference in the perception of the infant’s beauty and desirability. Families may reinforce qualities such as being mindful of discrimination and mistrust of authorities and law enforcement personnel.
A cost-effective multi-track introduction to Linux, Git and GitHub

Currently about 60% to 65% of servers on the internet run a version of Linux or Unix. Android, the world's most popular mobile operating system, is a Linux-based system; many devices run on the Linux kernel, and Linux skills are in demand in both industry and research. By allowing Computer Science students to graduate without exposure to this important platform, we are doing them a major disservice. This is not intentional - often small departments have to choose where to direct their limited resources, and procuring and setting up an infrastructure for a foundational Linux course may present a challenge. In this paper we describe our experience in offering such a course in our otherwise solidly Windows-based department. Our flexible course design offers students Linux experience from both the user and administrative sides. We also introduce version control using Git along with GitHub, another in-demand skill. Students also have the opportunity to learn how to work as a team on a challenging semester-long project using these tools. Our approach can be tailored to an institution's existing curricular goals, and without undue burden on the local IT infrastructure. The setup is very flexible and can be adopted as part of a separate module in a pre-existing class, e.g., in operating systems. We report on the results of our approach, what we learned, and what future changes we will make.
CHAPTER 4 – Sequential Estimation

Publisher Summary In some problems, hypothesis-testing seems to be somewhat artificial. In fixed-sample size situation, there is a close connection between acceptance regions and confidence regions, whereas, such an analogy does not hold in the sequential situation—therefore, the need for a theory of sequential estimation. The stopping rules employed in sequential testing might not be meaningful in sequential estimation. The problem of determining confidence intervals of preassigned length and confidence coefficient for the mean of a normal population with unknown variance is solved by the same procedure. To make either the power of the test or the length of the confidence interval free of the variance, it seems necessary to waste a small portion of the information contained in the sample.
Concerning isothermal self-similar blast waves. I - One-dimensional flow and its stability. II - Two-dimensional flow and its stability

One-dimensional self-similar isothermal flow behind a blast wave propagating in a medium whose density varies with distance is investigated for the cases of one-dimensional and two-dimensional flow. The isothermal flow model is adopted as an alternative to adiabatic models of self-similar flow, which neglect heat flux. The topology of the one-dimensional flow solutions, the singularities, and the influence of boundary conditions are discussed; the instability of the isothermal blast waves against nonself-similar perturbations is also considered. The number of critical points in the two-dimensional solutions is found to vary from the number in the one-dimensional problem.
Solvable Chaos as a Tool for Evaluating Wideband Delay Cells in Matched Filters

We show the development of a wideband delay guided by the closed-form, analytic solution of a solvable chaotic oscillator. This delay serves as a crucial component in the design of a matched filter receiver that optimally detects chaotic waveforms in the presence of noise. Unlike most chaotic systems, a special class of solvable chaos permits a closed-form analytic expression that may be used to guide designs. Specifically, we employ a cascade of 7th-order Bessel filter cells to accommodate various bandwidths associated with these oscillators. These bandwidth increments are guided by a closed form expression of the chaotic signals' spectral content. The resulting delay has wideband frequency characteristics while keeping group delay maximally flat within the operating band. Next, we analyze our results through time series comparison of the delayed signals with corresponding, analytically reconstructed chaotic waveforms. Finally, we summarize the trade-off space for these delay designs informed by analytic solution. Our results show that these finite bandwidth delay designs impose a 13% deviation from analytic time series expectations when 4 spectral lobes are considered and 17 % deviation for 3 spectral lobes.
The Role of Accounting Conservatism in Mitigating Bondholder-Shareholder Conflicts over Dividend Policy and in Reducing Debt Costs

Using both a market-based and an accrual-based measure of conservatism, we find that firms facing more severe conflicts over dividend policy tend to use more conservative accounting. Furthermore, we document that accounting conservatism is associated with a lower cost of debt after controlling for other determinants of firms' debt costs. Our collective evidence is consistent with the notion that accounting conservatism plays an important role in mitigating bondholder-shareholder conflicts over dividend policy, and in reducing firms' debt costs.
The effect of variable temperature, humidity, and substrate wettability on Gecko (Gekko gecko) locomotor performance and behavior

Adhesive and locomotor performances of geckos are inherently linked by specialized morphological and biomechanical features. As such, we predict that conditions that lead to poor adhesive performance (i.e., low resistance to applied force while clinging) also lead to poor locomotor performance and behavior (i.e., slowed running speed, increased frequency and duration of stops, more failed or incomplete runs). In this study, we test the prediction that running speed changes as a function of adhesive performance in variable temperature (12 and 32°C), humidity (30, 55, 70, 80% relative humidity), and substrate wettability (hydrophilic glass, intermediately wetting plexiglass). We also expect other locomotor performance traits and behaviors, such as stopping and avoiding treatment conditions, to change as a function of adhesive performance. The results of this study do not fully support our prediction: gecko locomotor performance does not change as a function of humidity or substrate wettability, unlike adhesive performance. As an anticipated result of ectothermy, geckos run significantly slower and stop more frequently and longer at 12°C than 32°C. At high temperature, geckos required significantly more running attempts on hydrophilic glass than plexiglass to complete the experimental procedure, suggesting that this treatment condition is unfavorable. The results of this study highlight the robust locomotive response of geckos to variation in adhesive performance and environmental conditions, and have significant implications for predictions about habitat use and behavior in their natural environment.
Effectiveness of Expanded Food and Nutrition Education Program in Changing Nutrition-Related Outcomes Among Adults With Low Income: A Systematic Review

Abstract Objective To review the effect of the Expanded Food and Nutrition Education Program (EFNEP) in changing nutrition-related outcomes. Methods Relevant research conducted before December 2020 was identified using PubMed, Web of Science, Google Scholar, and the EFNEP Research Database. The methodological quality of each eligible study was assessed. Results Of the 406 studies found, 30 were eligible; 26 studies were on EFNEP, and 4 included both EFNEP and Supplemental Nutrition Assistance Program Nutrition Education (SNAP-Ed). The sample sizes ranged from 35 to 122,961. Outcome measures included consumption of food groups, nutrients, other nutrition-related behaviors, and food security. At least 1 immediate behavior change (P Discussion This review found a consistent, immediate improvement in nutrition behaviors after program participation but poor retention over time. Overall, variation in programming and outcome measures, incomplete reporting, and generally low study quality by modern standards precluded strong conclusions. Implications for Research and Practice This review identified the need for control groups, improved reporting of program protocols, theory-based curriculum, and measurement of long-term outcomes.
Literacy-related skills among children after left or right hemispherectomy.

Abstract Objective Following hemispherectomy surgery, children’s educational outcomes are of great importance but are understudied. The study goal was to investigate reading, language, and nonverbal cognitive skills in children obligatorily relying on a left versus right hemisphere using a cross-sectional design. Methods Participants (ages 6–18) who had undergone left hemispherectomy (LH; n = 10) or right hemispherectomy (RH; n = 14) completed standardized measures of reading, language, and nonverbal cognition. Results LH and RH groups were balanced for socioeconomic status, sex, and age. Both groups scored below the population mean across standardized measures (RH: −0.79 to −1.95 SDs; LH: −0.97 to −2.32 SDs). Compared to the LH group, the group retaining a functional left hemisphere (RH group) learned to read sooner (p = .011) despite no significant differences for surgery age, and scored higher on untimed real word and pseudoword reading measures (p Significance Investigations of psychoeducational skills in reading, language, and nonverbal cognition among children who have undergone hemispherectomy can offer important insights into compensatory potential for left and right hemispheres as well as inform educational programming for children following medical stabilization.
Semi-blind Channel Estimation and Data Detection for Time-Varying Massive MIMO System

A semi-blind algorithm based on expectation propagation (EP) is proposed for multi-cell massive MIMO systems with spatially and temporally correlated channels. The performance of the algorithm in channel estimation and data detection is obtained from simulations and compared to other approaches. The results show that with only K pilots, where K is the number of users in the cell, the channel estimation performance of the proposed method approaches a lower bound as the number of BS antennas or the number of data symbols per frame increase. As expected, for time-varying channels, the proposed algorithm clearly outperforms those designed for block-fading channel models.
Effects of experimental multi-season drought on abundance, richness, and beta diversity patterns in perennially flowing stream insect communities

Freshwater systems are projected to experience increased hydrologic extremes under climate change. To determine how small streams may be impacted by shifts in flow regimes, we experimentally simulated flow loss over the span of three summers in nine 50 m naturally fed stream channels. The aquatic insect community of these streams was sampled before, during, and after experimental drought treatments as well as following one unforeseen flood event. Abundance, richness, and beta diversity were measured as indicators of biotic effects of altered flow regimes. Abundance declined in proportion to flow loss. In contrast, we observed a threshold response in richness where richness did not decrease except in channels where losses of surface flow occurred and disconnected pools remained. The flood reset this pattern, but communities continued their prior trajectories shortly thereafter. Beta diversity partitions suggested no strong compositional shifts, and that the effect of drought was largely experienced uniformly across taxa until flow cessation. Pools served as a refuge, maintaining stable abundance gradients and higher richness longer than riffles. Upon flow resumption, abundance and richness returned to pre-treatment levels within one year. Our results suggest that many taxa present were resistant to drought conditions until loss in surface flow occurred.
New Approaches to Detection and Characterization of PTH Receptors

PTH receptors have been demonstrated in several cell types and in isolated membranes from these cells. Putative receptors for both the amino terminal (1–10) and carboxy terminal (11,12) domains of the hormone have been reported. While the receptors for the amino terminal portions of PTH are believed to be related to activation of adenylyl cyclase, the function of receptors for carboxy terminal segments of this peptide is unknown.
Aquaculture Technology for Producers

The major limitations to the development of aquaculture in many regions are availability of water resources and environmental impact. Water is critical to aquatic animals, for it both serves as the medium that supplies the required oxygen and creates the physical environment that allows for movement of the animals. As world population has grown and industries have increased their production to meet the demands of the growing population, water has become a scarce resource that has had many conflicting demands placed upon it. Consequently, the major strategy for increasing aquaculture production with this limited water resource is production intensification. As fish biomass density increases, however, the amount of oxygen dissolved naturally in water becomes limited, thus necessitating supplemental aeration and oxygenation. In addition, the increased use of artificial feed as a means to developing a high density culture system leads to water pollution that stems from the facts that aquatic animals cannot completely utilize the feed and that the animals will excrete other metabolic products such as ammonia that are toxic to the aquatic animals at elevated levels. Internally, the waste produced deteriorates the water quality and makes the water unsuitable for fish to live in, while externally, discharge of the polluted water, if not properly managed, may lead to adverse effects on the environment. Keywords: aquaculture; production intensification; aquatic species; pond systems; hybrid ponds; levees; catfish ponds; rainbow trout; therapeutant components
The origin of the nonmigrating tidal structure in the column number density ratio of atomic oxygen to molecular nitrogen

[1] The longitudinal modulation of the column number density ratio of atomic oxygen to molecular nitrogen (O/N2 ratio) is interpreted as a tidal structure in the thermospheric neutral composition. However, the close similarity between the tidal structures in the ionosphere and O/N2 ratio raises a question regarding this interpretation. We examine the origin of the tidal structure in the O/N2 ratio by using the thermospheric limb data for 2003 provided by the Global Ultraviolet Imager onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite. Our results show that the longitudinal variation of the O/N2 ratio at the location of the equatorial ionization anomaly (EIA) is accounted for by the 135.6 nm emission produced by the EIA. Because the O/N2 ratio derived from optical observations is contaminated by the radiative O+ recombination, the O/N2 ratio is not a useful indicator of the tidal structure in the thermosphere.
Stability of Physical Performance Test Scores

Abstract On each of three days 73 subjects were administered three trials of a standing broad jump test, and 48 subjects were administered five trials of a side-step test. A significant trial-to-trial variability within days was found for the side-step test. For both the standing broad jump and side-step tests a significant variability among days was found at the .05 level. These findings seem to indicate that a stable test score is not obtained the first two days a subject is administered a physical performance test.
Environment drives forage fish productivity.

Understanding the interaction between fishing and natural variations in productivity is a central question in fisheries management. Essington et al. (1) advance the discussion on drivers of forage fish dynamics by highlighting the role of natural decreases in biomass collapses. A key conclusion of their work is that fishing increases the magnitude and frequency of collapse in biomass. More intense fishing necessarily results in fewer fish; however, the higher exploitation rates commonly seen as forage fish biomass declines do not always mean that fishing precipitated collapses in productivity.
Autolytic Enzyme System of Streptococcus faecalis IV. Electron Microscopic Observations of Autolysin and Lysozyme Action

Cell walls (LOG walls) were isolated from cultures of Streptococcus faecalis ATCC 9790 in the exponential phase of growth. These walls were either allowed to undergo autolytic dissolution (in the presence or absence of trypsin) or wall autolysis was inactivated with sodium dodecylsulfate (SDS walls). Inactivated walls were treated either with lysozyme or with isolated, partially purified S. faecalis autolysin. During wall lysis, samples were removed, negatively stained with phosphotungstate, and examined in the electron microscope. Both lysozyme and isolated autolysin appeared to act over the entire surface of SDS walls. After partial dissolution, a fibrous network over the surface was revealed. Lysozyme digestion revealed the presence of prominent, highly-contrasted equatorial and subequatorial bands around the walls. After trichloroacetic acid extraction, the bands were seen less frequently and less distinctly in the partially lysozyme digested walls, suggesting that the bands contained nonpeptidoglycan polymers. In the absence of trypsin (which activates a latent form of the autolysin), autolysis of LOG walls appeared to start at the equatorial bands and to proceed back towards the apex of the coccus. Ribbons of wall material coming off the wide edge of the nearly hemispherical wall fragments were observed. Activation of latent autolysis resulted in lytic action over the entire wall surface. The results are consistent with the previously postulated location of active autolysin at the areas of new wall synthesis and the random location of latent autolysin in LOG walls.
Interactions between pharmaceutical representatives and doctors in training. A thematic review.

OBJECTIVE: Medical school and residency are formative years in establishing patterns of prescribing. We aimed to review the literature regarding the extent of pharmaceutical industry contact with trainees, attitudes about these interactions, and effects on trainee prescribing behavior, with an emphasis on points of potential intervention and policy formation.
Intracranial Hemorrhage and Amphetamine Usage: Review of the Effects of Amphetamines On the Central Nervous System

A 25-year-old man died after an intravenous injection of 100 mg of methedrine. Postmortem studies showed visceral congestion, lung edema, pericardial petechiae, centrolobular necrosis of the liver, and diffuse subarachnoid blood, intracranial vasculitis and cerebritis in the absence of aneurysms, arteriovenous malformations or chronic hypertension. A review of the English-language literature produced 3 other cases of fatal amphetamine-induced intracranial hemorrhage and seven nonfatal cases. Some were the result of overdose, others of hypersensitivity. Angiographic evidence suggests that such hemorrhages result from the development of fibrinoid necrosis and the formation of microaneurysms in the small intracerebral vessels.
Early changes in degenerating mouse sciatic nerve are associated with endothelial cells.

Abstract This study determines the earliest reproducible biochemical change in nerve undergoing Wallerian degeneration by assessing the timing, magnitude, and specificity of changes in markers of cellular function in distal stumps of transected mouse sciatic nerves. Analysis of temporal changes in synthesis of DNA, RNA, protein, and in activity of ornithine decar☐ylase in transected and sham-operated nerves 0–5 days postoperatively indicated that incorporation of [3H]thymidine, a marker of premitotic activity, was the earliest and only specific marker of early Wallerian degeneration. Although the 3–4 day peak in [3H]thymidine incorporation in distal stumps of transected mammalian nerves is known to reflect Schwann cell mitosis, light-microscopic autoradiographic studies of nerve stumps at the onset of the [3H]thymidine response (1 day post-transection) revealed preferential labeling of endothelial cells lining intrafascicular capillaries.
Diffusion and Ionic Conductivity in Cesium Bromide and Cesium Iodide

The diffusion coefficients of the constituent ions were measured in CsBr and CsI single crystals between 300\ifmmode^\circ\else\textdegree\fi{}C and 550\ifmmode^\circ\else\textdegree\fi{}C by means of radioactive tracers and were compared with electrical conductivity measurements. Approximate satisfaction of the Nernst-Einstein equation indicates that the conductivity is nearly completely ionic and the diffusion measurements show that the halogen ion defects are the more mobile. Attempts to identify the mechanisms for ionic transport by means of the Bardeen-Herring correlation factor are discussed. Schottky defects seem likely but the assumption of an additional mechanism for cationic transport is required. If Schottky defects are predominant their formation enthalpies are 2.0 ev and 1.9 ev in CsBr and CsI respectively, and the activation enthalpies for halogen vacancy motion are 0.27 ev and 0.3 ev respectively, while the cesium vacancy activation enthalpy is about 0.58 ev for both salts.
Toxicity of IL-2 and Corynebacterium Parvum following direct intracranial injection

The toxicity of IL-2 and/or C. Parvum when injected directly into the mouse brain was examined by survival and histopathology using different numbers of injections, different doses of IL-2, different solvents for the IL-2, and different doses and routes of administration of C. Parvum. Two injections was found significantly to increase mortality (19%) over a single injection (4%). Mortality from two injections of 30,000 U (23%) or 60,000 U (20%) was higher than from two injections of 15,000 U (12%). The mortality from two injections with normal saline as solvent was much higher (29%) than from two injections with sterile water (19%) or D5W (9%). Two injections of IL-2 given simultaneously with C. Parvum showed a much higher mortality (26%) than other doses and routes of C. Parvum administration. Mice dying acutely (6-24 days) of toxicity showed an extensive mononuclear infiltrate at the site of injection. The brains of surviving mice (sacrificed at 30 days) showed a mild residual mononuclear cell infiltrate with the exception of mice which had received IL-2 and C. Parvum simultaneously. Brains from this latter group had an extensive residual mononuclear cell infiltrate.
The effect of visual deprivation on perceptual behavior

Abstract Monocularly reared cats manifest profound initial deficiencies in perceptualmotor coordination, in depth estimation on a visual cliff, and in the ability to discriminate visual forms differing in orientation when using only their deprived eyes. When the cats were subsequently exposed to a normal visual environment, not all these deficits proved permanent. Only the discrimination of visual form, the interocular transfer of form discrimination from the deprived to the experienced eye, and fine visually-guided spatial adjustments remained permanently absent. The more permanent visual deficiencies cannot be attributed to scotomata nor to losses in visual resolution, since measurements of visual acuity utilizing an optokinetic response elicited by fine black moving lines did not reveal large losses in resolution. The comparison of the neurophysiological and behavioral analysis on the same visually deprived cats leads us to conclude that visual cortex neurons with very selective receptive fields are particularly important in mediating visual form discrimination and fine spatial adjustments.
On-the-hand measurement methods for assessing effectiveness of anti-vibration gloves

Abstract Several technical difficulties have been associated with the current test and evaluation methods for assessing the vibration isolation effectiveness of anti-vibration gloves. The effectiveness of the gloves for specific powered hand tools can be assessed through measurement of acceleration on the head of the third metacarpal or at the wrist. In the present study, the reliability of these on-the-hand measurement methods is evaluated through assessing the vibration transmissibility of gloves while operating chipping hammers. Two different methods, with and without the prior knowledge of tool vibration, for deriving the transmissibility of the gloves are also evaluated. The study used an air bladder glove and a gel-filled glove, two chipping hammers, and feed forces in the 50–200 N range. Six male volunteers were used as test subjects. The transmissibility of the gloves is also estimated using a total vibration transfer function method. The results suggest that the on-the-hand methods offer some unique advantages over the palm adapter method outlined in ISO-10819, but they suffer from poor repeatability when a high degree of tool vibration variability is observed, especially if the tool vibration is not measured and used for the assessment. Glove transmissibility measured at the third metacarpal is more repeatable than that derived from the measurements at the wrist. Reasonably good agreements were observed between the predicted and measured transmissibility values of the air glove. However, the measured transmissibility values for the gel-filled glove suggest that it may perform better than as predicted using the transfer function method. Relevance to industry Prolonged exposure to hand-transmitted vibration has been related to an array of health disorders of the vascular, nervous and musculoskeletal systems in the upper extremity. Anti-vibration gloves can be used to help reduce the severity of vibration exposure. The current glove assessment methods exhibit several technical difficulties and do not provide information regarding the effectiveness of the gloves when used with specific power tools. This study examines the effectiveness of on-the-hand measurement methods and the transfer function-based prediction method to determine more reliable glove assessment methods. The study also proposes a test device and method for assessing the vibration effectiveness of gloves when used with pneumatic hammers. It is anticipated that the proposed glove assessment method would be applicable to other types of hand-held power tools.