cssi/SciSciGPT-SciSciNet huggingface dataset:
A Quantitative Study of Deep Learning Training on Heterogeneous Supercomputers

Deep learning (DL) has become a key technique for solving complex problems in scientific research and discovery. DL training for science is substantially challenging because it has to deal with massive quantities of multi-dimensional data. High-performance computing (HPC) supercomputers are increasingly being employed for meeting the exponentially growing demand for DL. Multiple GPUs and high-speed interconnect network are needed for supporting DL on HPC systems. However, the excessive use of GPUs without considering effective benefits leads to inefficient resource utilization of these expensive setups. In this paper, we conduct a quantitative analysis to gauge the efficacy of DL workloads on the latest HPC system and identify viability of next-generation DL-optimized heterogeneous supercomputers for enabling researchers to develop more efficient resource management and distributed DL middleware. We evaluate well-known DL models with large-scale datasets using the popular TensorFlow framework, and provide a thorough evaluation including scalability, accuracy, variability, storage resource, GPU-GPU/GPU-CPU data transfer, and GPU utilization. Our analysis reveals that the latest heterogeneous supercomputing cluster shows varying performance trend as compared to the existing literature for single- and multi-node training. To the best of our knowledge, this is the first work to conduct such a quantitative and comprehensive study of DL training on a supercomputing system with multiple GPUs.
Evaluation of STAR and Kallisto on Single Cell RNA-Seq Data Alignment

Alignment of scRNA-Seq data are the first and one of the most critical steps of the scRNA-Seq analysis workflow, and thus the choice of proper aligners is of paramount importance. Recently, STAR an alignment method and Kallisto a pseudoalignment method have both gained a vast amount of popularity in the single cell sequencing field. However, an unbiased third-party comparison of these two methods in scRNA-Seq is lacking. Here we conduct a systematic comparison of them on a variety of Drop-seq, Fluidigm and 10x genomics data, from the aspects of gene abundance, alignment accuracy, as well as computational speed and memory use. We observe that STAR globally produces more genes and higher gene-expression values, compared to Kallisto, as well as Bowtie2, another popular alignment method for bulk RNA-Seq. STAR also yields higher correlations of the Gini index for the genes with RNA-FISH validation results. Using 10x genomics PBMC 3K scRNA-Seq and mouse cortex single nuclei RNA-Seq data, STAR shows similar or better cell-type annotation results, by detecting a larger subset of known gene markers. However, the gain of accuracy and gene abundance of STAR alignment comes with the price of significantly slower computation time (4 folds) and more memory (7.7 folds), compared to Kallisto.
GENETIC AND BIOCHEMICAL ANALYSIS OF THE A/ANN ARBOR/6/60 COLD-ADAPTED MUTANT

Using a variety of techniques including recombinational analysis, oligonucleotide mapping of viral RNA and comparative polyacrylamide gel electrophoresis of double-stranded RNA hybrids or viral polypeptides, we have detected mutations in all eight segments of the RNA of the A/Ann Arbor/6/60 cold-adapted and temperature-sensitive mutant. These mutations do not appear to affect the synthesis of virus-specific proteins, all of which can be detected in cells infected at the restrictive temperature. The presence of multiple RNA mutations in the attenuated mutant A/Ann Arbor/6/60 and the reproducible transfer of the six nonglycoprotein genes to recombinants may aid the preparation of reproducibly attenuated and phenotypically stable live attenuated influenza vaccine strains.
Examining The Work Experience of Programmers with Visual Impairments

The rapid rise and ubiquity of computing has led to tremendous growth in the field of software development; growth that has outpaced society’s ability to fill available positions. The gap between this large number of openings and the decidedly smaller pool of qualified candidates available to fill them has created opportunities for individuals from non-traditional backgrounds to pursue careers in software development. Due to the nature of their disability, blind and low vision persons have not to date been heavily pursued as candidates for software development positions given the arguably visually demanding nature of the practice. As such, we argue, there are significant knowledge gaps as it pertains to how visual impairment may impact a developer’s contribution to a software development team. To explore this issue we interviewed 11 visually impaired software developers about their experiences. Our findings suggest that workplace dynamics, project management practices, and tool accessibility are among the most significant challenges for these developers. We argue that this work furthers the understanding of visually impaired software developers which contributes to the movement towards accessible workplace environments and employment equity in software development.
Quarantine fatigue thins fat-tailed coronavirus impacts in U.S. cities by making epidemics inevitable

Abstract We use detailed location data to show that contact rates in most U.S. cities are fat tailed, suggesting that the fat tails previously documented in a small number of case studies are widespread. We integrate these results into a stochastic compartmental model to show that COVID-19 impacts were also fat tailed for many large U.S. cities for several weeks in the spring and summer. Due to thresholds in epidemiological dynamics, fat-tailed impacts would have been more prevalent if not for the gradual increase in contact rates throughout the summer that made an outbreak more certain.
2020 - State of our JCMR.

There were 79 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2019, including 65 original research papers, 2 reviews, 8 technical notes, 1 Society for Cardiovascular Magnetic Resonacne (SCMR) guideline, and 3 corrections. The volume was down slightly from 2018 (n = 89) with a corresponding 5.5% increase in manuscript submissions from 345 to 366. This led to a slight decrease in the acceptance rate from 25 to 22%. The quality of the submissions continues to be high. The 2019 JCMR Impact Factor (which is published in June 2020) increased from 5.07 to 5.36. The 2020 impact factor means that on average, each JCMR published in 2017 and 2018 was cited 5.36 times in 2019. Our 5 year impact factor was 5.2. We are now finishing the 13th year of JCMR as an open-access publication with BMC. As outlined in this report, the Open-Access system has dramatically increased the reading and citation of JCMR publications. I hope that our authors will continue to send their very best, high quality manuscripts for JCMR consideration and that our readers will continue to look to JCMR for the very best/state-of-the-art publications in our field. It takes a village to run a journal. JCMR is blessed to have very dedicated Associate Editors, Guest Editors, and Reviewers. I thank each of them for their efforts to ensure that the review process occurs in a timely and responsible manner. These efforts have allowed the JCMR to continue as the premier journal of our field. My role, and the entire process would not be possible without the dedication and efforts of our managing editor, Diana Gethers (who will leaving the journal in the coming months) and our assistant managing editor, Jennifer Rodriguez, who has agreed to increase her reponsibilities. Finally, I thank you for entrusting me with the editorship of the JCMR. As I begin my 5th year as your editor-in-chief, please know that I fully recognize we are not perfect in our review process. We try our best to objectively assess every submission in a timely manner, but sometimes don't get it “right.” The editorial process is a tremendously fulfilling experience for me. The opportunity to review manuscripts that reflect the best in our field remains a great joy and a highlight of my week!
Mapping Vegetation and Seasonal Thaw Depth in Central Alaska Using Airborne Hyperspectral and LiDAR Data

Field collection of permafrost vegetation and seasonal thaw depth measurements are a time consuming and labor intensive procedure. To address this, in this study we assessed the capacity of airborne hyperspectral and LiDAR data for upscaling in-situ point data to map vegetation and summer thaw depth at an experimental site near Fairbanks, Alaska, USA. The site represents roughly three quarters of the most common vegetation in the boreal and taiga permafrost zones. An overall accuracy of 93% was achieved for mapping five different vegetation types, and a correlation coefficient (r) of 0.66 was produced for thaw depth modeling using a machine learning algorithm when two remote sensing data sources were combined. Object-based vegetation and thaw depth maps were produced. This study demonstrates that fine spatial resolution hyperspectral data could be valuable for permafrost characterization, while the contribution from LiDAR was marginal at the testing site.
Storied Justice: The Narrative Strategies of U.S. Federal Prosecutors

This chapter demonstrates the value of ethnographic research to the study of lawyers’ composition of legal narratives. It focuses, as a case study, on the ethical and professional judgments embedded in American federal prosecutors’ creation and critiques of trial narratives. It draws on illustrative examples from ethnographic fieldwork to highlight aspects of real-time story creation that are formative of lawyers’ professional identities. My central argument is that justice is a product of lawyers’ competing narratives about evidence, the fairness of their cases, and the significance of their role as narrator and curator of a prosecution. In the process of jointly critiquing opening and closing statements, prosecutors make sense of their obligation to seek justice.
The Clean Air Act and Scenic Landscapes

The combination of the Clean Air Act, which seeks to provide clean air throughout the United States, and the Organic Act, which seeks to conserve the scenery of national parks, provides a double justification for ensuring that the air in national parks is particularly clear. Scenic values presume both an aesthetically appealing landscape and the ability of people to perceive it. But air pollution interferes with the ability to enjoy the scenic sights of national parks. This article uses the example of Theodore Roosevelt National Park (TRNP) in western North Dakota to examine the relationship between air pollution and national parks. First, it considers the nature of scenic values, how national parks seek to conserve them, and how those values are maintained at TRNP in particular. Second, it examines how air pollution interferes with visibility at national parks, how the CAA is supposed to eliminate that pollution, and how those efforts have fared at TRNP. Third, it considers why the CAA has struggled to eliminate air pollution from TRNP and other national parks. The experience at TRNP offers three lessons: the implementation of the CAA’s provisions will not necessarily accomplish the statutory goal, the public commitment to scenic values is not as strong as the statutory requirements for protecting those values, and the cooperative federalism framework embedded in the CAA confronts special difficulties in the context of visibility issues.
Hyperglycemia suppresses cardiomyocyte bioenergetic reserve independent of O-GlcNAcylation (1155.5)

Hyperglycemia, a hallmark of diabetes, can augment flux through accessory glucose metabolism pathways, such as the hexosamine biosynthetic pathway, which produces the sugar donor for the β-O-linked-N-acetylglucosamine (O-GlcNAc) post-translational modification of proteins. We examined whether hyperglycemia-induced elevations in O-GlcNAcylation of cultured neonatal rat cardiomyocytes (NRCMs) affected mitochondrial function using extracellular flux analysis. Hyperglycemia (33 mmol/L) augmented O-GlcNAcylation and suppressed mitochondrial reserve capacity (p<0.05); however, an osmotic control recapitulated the effect of hyperglycemia-suppressed reserve capacity (p<0.05) without increasing O-GlcNAcylation. Furthermore, neither adenoviral overexpression nor pharmacologic inhibition of either OGA or OGT altered mitochondrial reserve capacity. Specific interrogation of individual electron transport Complex II function showed that hyperglycemia reduced Complex II mediated oxygen consumption rate (OCR), which, aga...
Providing a Deputy to be Shot: Hegemonic Stability, Regional Powers, and Trade in the Developing World

Empirical evaluations of hegemonic stability theory have dwindled in the decades since the theory's inception in the late 1970s. This decline is partially a result of the limited number of hegemons the discipline has collected data on given that most projects only extend back to 1816 and only capture the tenures of Great Britain and the United States. This study overcomes the small-n problem by applying this theory of global power behavior to regional microcosms. Given the theoretical and empirical developments in the preceding decades, this paper articulates and tests two propositions for the period 1950-1990: 1) Expanding US power has a direct effect on the trade activity of states in developing regions and, more interestingly, 2) regional powers act as agents to a global hegemonic principal in expanding trade. The statistical evaluations presented here suggest that the articulated preferences of regional powers have a significant effect in determining the level of trade engaged in by the observed state. Thus, while unobstructed hegemony is most effective in increasing trade flows, rival regional powers are the second best option for liberalization.
Functions as Permutations: Regarding No Free Lunch, Walsh Analysis and Summary Statistics

Permutations can represent search problems when all points in the search space have unique evaluations. Given a particular set of N evaluations we have N! search algorithms and N! possible functions. A general No Free Lunch result holds for this finite set of N! functions. Furthermore, it is proven that the average description length over the set of N! functions must be O(N lg N). Thus if the size of the search space is exponentially large with respect to a parameter set which specifies a point in the search space, then the description length of the set of N! functions must also be exponential on average. Summary statistics are identical for all instances of the set of N! functions, including mean, variance, skew and other r-moment statistics. These summary statistics can be used to show that any set of N! functions must obey a set of identical constraints which holds over the set of Walsh coefficients. This also imposes mild constraints on schema information for the set of N! functions. When N = 2L subsets of the N! functions are related via Gray codes which partition N! into equivalence classes of size 2L.
A Users' Guide to Positive Guidance in Highway Control

Positive Guidance is an approach to enhance the safety and operational efficiency of hazardous locations. This approach joins the highway engineering and human factors technologies to produce an in...
Revising Relational Domain Theories

This paper presents the AUDREY system which can revise incomplete and incorrect relational domain theories given a set of examples and non-examples of concepts in the theory. Using an abductive process, the system identifies clauses that must be added, removed or generalized to modify the theory to be consistent with the training set. The generalization process generates first-order Horn clauses. We present experimental results demonstrating the system's ability to repair incorrect domain theories as well its ability to learn relational concepts.
Navier-Stokes Predictions of Multifunction Nozzle Flows

A two-dimensional, Navier-Stokes code developed by Imlay based on the implicit, finite-volume method of MacCormack has been applied to the prediction of the flow fields and performance of several nonaxisymmetric, convergent-divergent nozzles with and without thrust vectoring. Comparisons of predictions with experiment show that the Navier-Stokes code can accurately predict both the flow fields and performance for nonaxisymmetric nozzles where the flow is predominantly two-dimensional and at nozzle pressure ratios at or above the design values. Discrepancies between predictions and experiment are noted at lower nozzle pressure ratios where separation typically occurs in portions of the nozzle. The overall trends versus parameters such as nozzle pressure ratio, flap angle, and vector angle were generally predicted correctly.
Computational studies of blood flow in the heart in two and three dimensions

A computational model of blood flow in the heart is developed. The numerical method is based on the projection method for solving the time-dependent Navier-Stokes equations. This method has been used to study the flow of blood in both two-dimensional and three-dimensional models of the heart. The two-dimensional model has been used to study flows through the mitral valve, both natural and prosthetic. The three-dimensional heart model, based on anatomical dissections of the myocardial fiber paths, should be able to do in three dimensions the kinds of studies which have been successfully performed in two dimensions. Computer-generated videotapes showing results from both heart models are shown. >
A three-year evaluation of triclopyr for selective whole-bay management of Eurasian watermilfoil on Lake Minnetonka, Minnesota

AbstractImpact of whole-bay, low-dose triclopyr applications for selective control of Eurasian watermilfoil (Myriophyllum spicatum: EWM) was evaluated on Lake Minnetonka, Minnesota, from 2011 to 2013. To assess invasive and native plant frequency and abundance over multiple seasons following management, we collected plant frequency, herbicide concentration, biomass, and hydroacoustic data. Two enclosed bays, St. Albans (64 ha) and Grays (64 ha), were treated at 300 μg/L. St. Albans was treated in late May 2011 and 2013 and Grays was treated in late May 2012. Triclopyr half-lives ranged from 8.6 to 12.1 days. A larger, more open bay, Gideons (133 ha), was treated by targeting 50 ha of EWM beds at 1500 μg/L in early June 2011. Triclopyr half-lives in Gideons treatment blocks averaged 3.7 days with a bay-wide half-life of 9.4 days. Near complete loss of EWM in the 3 bays was observed the year of treatment. Increased EWM frequency was observed the following June and August; however, EWM remained a minor compo...
Application of membrane filters.

Publisher Summary This chapter illustrates membrane filtration that has been evaluated by numerous investigators in the field of public health. It is used in analysis of water for determining the presence of coliform and various pathogenic organisms. Membrane filtration is used for isolation of specific microorganisms, such as E. coli, S. typhosa, M . tuberculosis, B . suis, Bacillus anthracis, and various yeasts and pollens. In the dairy industry, membrane filters are used in bacteriological analysis of milk, sterilization of liquid additives, routine checks of water supplies, and examination of containers and pipes. In medical or clinical procedures, membrane filters are utilized for analysis of sputum, spinal fluid, and urine. The sputum, urine, or spinal fluid must be treated prior to the filtration. In aerobiology, membrane filtration can be used for collection and analysis of pollen and bacteria. While membrane filter retention of organisms directly collected from air did not present any special difficulties, the maintenance of the viability of the organisms can be a problem.
A Review Of “Sunny Land Pictures from Paradise”

Michael Carlebach's knowledge and practice of photojournalism is well-known. His books American Photojournalism Comes of Age and The Origins of Photojournalism in America are considered by many bib...
Microparticulate β-glucan vaccine conjugates phagocytized by dendritic cells activate both naïve CD4 and CD8 T cells in vitro.

Microparticulate β-glucan (MG) conjugated to vaccine antigen has been shown to serve as an effective adjuvant in vivo. To further study antigen presentation by MG:vaccine conjugates, bone marrow-derived dendritic cells (BMDC) were treated with MG conjugated to ovalbumin (OVA), then interacted with splenocytes from DO11.10 transgenic mice expressing an OVA peptide-specific T cell receptor. BMDC treated with MG:OVA induced significantly higher numbers of activated (CD25+CD69+) OVA-specific CD4+ T cells than BMDC treated with OVA alone. BMDC treated with MG:OVA upregulated CD86 and CD40 expression as well as MG alone, indicating that conjugation of OVA does not alter the immunostimulatory capacity of MG. Activation of CD8+ OVA-specific OT-1 cells showed that MG:OVA is also capable of enhancing cross-presentation by BMDC to CD8+ cytotoxic T cells. These results show that MG acts as an adjuvant to enhance antigen presentation by dendritic cells to naive, antigen-specific CD4 and CD8 T cells.
Clinical Nephrology and Dialysis in the 1990s

End-stage renal disease (ESRD) afflicts more than 200,000 patients in the United States today, and they undergo chronic dialysis or transplantation in order to sustain life. The primary causes of treated ESRD today are diabetes mellitus, hypertension, and glomerulonephritis. Hemodialysis remains the mainstay of therapy for patients, primarily due to the chronic shortage of organs available for transplantation. Technological advances have led to numerous improvements in hemodialysis therapy during the last 30 years. Dialysis is now provided in a variety of settings, including hospitals, outpatient dialysis units, and the home. Despite these advances, morbidity and mortality remain high for patients with ESRD. Patients with diabetes have the highest mortality rates primarily due to cardiac and infectious complications. Patients undergoing continuous ambulatory peritoneal dialysis (CAPD) are generally younger and healthier than their hemodialysis counterparts. Mortality is lower in the CAPD group for younger...
Short- and long-term outcomes of laryngeal cancer care in the elderly

Objectives/Hypothesis To examine associations between pretreatment variables, short-term and long-term swallowing and airway impairment, and survival in elderly patients treated for laryngeal squamous cell cancer (SCCA). Study Design Retrospective analysis of Surveillance, Epidemiology, and End Results-Medicare data. Methods Longitudinal data from 2,370 patients diagnosed with laryngeal SCCA from 2004 to 2007 were evaluated using cross-tabulations, multivariate logistic regression, and survival analysis. Results Dysphagia (odds ratio [OR] = 1.5 [1.2–1.7]), weight loss (OR = 1.3 [1.1–1.6]), esophageal stricture (OR = 3.8 [2.5–5.9]), airway obstruction (OR = 1.9, [1.6–2.3]), tracheostomy (OR = 1.5 [1.2–1.9]), and pneumonia (OR = 1.8 [1.4–2.2]) increased 1 year after treatment. The odds of airway obstruction, esophageal stricture, and pneumonia increased over subsequent years, with significantly increased risk at 5 years for airway obstruction (OR = 3.3 [1.8–5.8]) and pneumonia (OR = 5.2 [2.5–10.7]). Pretreatment dysphagia, chemoradiation, and salvage surgery were significant predictors of long-term dysphagia, weight loss, tracheostomy, and gastrostomy, with pretreatment dysphagia and salvage surgery also associated with pneumonia. Surgery and postoperative radiation was associated with long-term dysphagia (OR = 1.4 [1.0–1.9]) but reduced odds of long-term pneumonia (OR = 0.7 [0.5–0.9]). Long-term dysphagia, gastrostomy or tracheostomy dependence, weight loss, airway obstruction, and pneumonia were associated with poorer survival, with pneumonia associated with the greatest risk of death at 5 years (hazard ratio = 2.6 [2.4–2.9]). Conclusions Airway and swallowing impairment is common after laryngeal SCCA treatment in elderly patients, increases over time, and is associated with poorer survival—with pneumonia associated with the highest risk of long-term mortality. Patients with pretreatment dysphagia, initial treatment with chemoradiation, and salvage surgery represent a high-risk group with an increased risk of disability and death. Level of Evidence 2c. Laryngoscope, 125:924–933, 2015
Production by Salmonella typhimurium of 2,3-Dihydroxybenzoylserine, and Its Stimulation of Growth in Human Serum

Transferrin, an iron-binding protein in the sera and tissue fluids of vertebrates, functions primarily as an iron-transport agent [1], but it also may serve as a component of nonspecific defense mechanisms against microbial infection [2, 3]. In normal adult human serum the transferrin is only onethird saturated with iron, and no free iron can be detected by colorimetric methods [4]. To grow in body fluids an organism may, therefore, possess a mechanism for utilizing some of the iron in transferrin.
The relationship between socioeconomic factors and gang violence in the City of Los Angeles.

Objective: To investigate the relationship between community-level socioeconomic factors and the incidence of gang-related homicide in the city of Los Angeles. Methods: An ecological group-level analysis was conducted to correlate the 5-year incidence rates (from 1988 through 1992) of gang-related homicide with community-level socioeconomic statistics for the 18 geographically distinct Los Angeles Police Department divisions. Eight socioeconomic factors were examined: (1) log mean per capita income, (2) proportion employed, (3) proportion high school graduates, (4) proportion single-parent families, (5) proportion male, (6) proportion younger than 20 years of age, (7) proportion African American, and (8) proportion Hispanic. Pearson correlation coefficients were calculated for the interrelationships among the study variables and gang-related homicide. Adjusted regression estimates were calculated from a multiple linear regression model. Results: The overall 5-year gang-related homicide rate for the city was 48.8 per 100,000, with a range of 5.2 to 173.5 per 100,000 among the different Los Angeles Police Department divisions. Pearson correlation coefficients revealed that the strongest negative correlations with gang-related homicide were log mean per capita income and proportion employed, and the strongest positive correlations were proportion single-parent families and proportion younger than 20 years of age. With mutual adjustment of all variables, only log mean per capita income and proportion employed were significantly associated with gang-related homicide. Conclusion: At the community level, gang-related homicide in Los Angeles is most closely associated with lower income and unemployment. These relationships may provide important insights into the causes of gang formation and gang violence.
An analytical method of estimating the domain of attraction for polynomial differential equations

A system of nth-order differential equations with polynomial right-hand sides is considered, and a simple analytical method of estimating the domain of attraction is developed. The method involves an ordinary quadratic Lyapunov function /spl upsi/=X/sup T/Q(Y)X with a certain parameter vector Y from the same state space. All linear factors in the expression for /spl upsi//spl dot/ are bounded in the domain /spl upsi//spl les/1, and the derivative is bounded by a quadratic function, the negativeness of which determines the restrictions for Y. The domain of attraction is estimated through a simple scaling of the obtained area or through its nonlinear transformation with optimization. The method allows for obtaining domains (for example, with infinite volume) that are comparable with ones obtained by complicated computational procedures. A set of examples is presented. >
Maize NDC80 is a constitutive feature of the central kinetochore.

In yeast and animals, Nuclear Division Cycle 80 (NDC80) is an important kinetochore protein that binds to microtubules and mediates chromosome movement. Its localization pattern is unusual, since it is generally not viewed as either an inner (centromeric chromatin) or outer (regulatory) component of the kinetochore. Here we report the characterization of NDC80 in a higher plant. By taking advantage of the large meiotic kinetochores of maize, we were able to show that NDC80 localizes outside of the constitutive kinetochore protein CENP-C. Further, a detailed analysis of mitosis indicates that NDC80 is stably present on kinetochores throughout the cell cycle. The quantity of NDC80 positively correlates with measured quantities of DNA and CENP-C, suggesting that NDC80 rapidly associates with DNA following replication and is stably maintained at centromeres during cell division. The data suggest that in plants NDC80 is on par with ‘foundation’ kinetochore proteins such as CENH3 and CENP-C.
Autoradiographic Measurement of Cerebral Lactate Transport Rate Constants in Normal and Activated Conditions

We used quantitative autoradiography to measure the regional rate constants of blood-to-brain transport of lactate in normal rats and rats treated with kainic acid. Mean cerebral values of lactate transport rate constants were not significantly different between the normal and treated rats, being 0.13 and 0.14 min-1 (ml/g), respectively. Regional values were also generally similar between the groups, but structures that are known to be activated by kainic acid showed increased values in the treated rats compared with rates in the controls. Our measured values of lactate transport rate constants are approximately 50% as great as those published for glucose, indicating that blood-brain transfer of lactate can be significant. This observation supports the hypothesis that radiolabel derived from glucose can leave the brain as radiolabeled lactate in conditions in which intracerebral lactate concentration rises, a hypothesis that has previously been presented to explain differences between rates of accumulation of radiolabel derived from deoxyglucose and glucose in such conditions.
Spermatogenic cyst and organ culture in Drosophila pseudoobscura

Spermatogenesis is a complex series of processes that involves (1) the maintenance of a renewable pool of diploid stem cells within a niche, (2) the mitotic expansion of a subpopulation of stem cells committed to the spermatogenic pathway, and (3) the differentiation of diploid cells into highly specialized, haploid spermatozoa through meiotic and post-meiotic cellular transformations. Drosophila melanogaster is a desirable model for studying spermatogenesis, as similarities exist between mammalian and fly spermatogenesis. Like mammals, flies maintain a spermatogenic stem cell niche; the steps involved in mammalian spermatogenesis are mimicked in flies, with the main difference being that fly sperm develop within cysts rather than an epithelial cell layer. Here, we report a reliable robust system for culturing whole testes and individual spermatogenic cysts obtained from mid- to late-pupal stages of Drosophila pseudoobscura. D. pseudoobscura testes can be easily distinguished in later pupal stages because of their intense red pigmentation and are easily handled because of their simple ellipsoidal morphology. Cultured cysts are comparable in length to cysts obtained from adult flies, and motility is consistently achieved in vitro. This system not only offers a method for dissecting the mechanisms involved in meiotic and post-meiotic cellular transformations, but also can be used for the study of signaling during spermatogenesis.
Synchrotron x-ray study of a Fibonacci superlattice

Quasiperiodic ordering is studies in a GaAs-AlAs Fibonacci superlattice by high-resolution x-ray scattering. The data are consistent with the predicted dense set of diffraction vectors. Moderately large growth fluctuations in the sequential deposition of GaAs and AlAs layers do not appear to disturb seriously the quasiperiodic order. The effects of randomness are analyzed in a computer simulation.
Presentness in Displaced Sound

ABSTRACT The author discusses her works that explore sound's influence on creating a sense of presentness and her aim to increase the audience's awareness of this influence.
Anxiety in intergroup relations: a comparison of anxiety/uncertainty management theory and integrated threat theory

Abstract In this article we review two theories in which anxiety and its relationship to intergroup relations play a central role: anxiety/uncertainty management (AUM) theory and the integrated threat theory (ITT) of prejudice. The antecedents and consequences of anxiety in each theory are presented and comparisons between the theories are drawn. AUM specifies a greater range of antecedents, while ITT specifies a greater range of threats. The theories differ in the conceptualizations of the effects of anxiety with AUM holding that anxiety often has beneficial effects on intergroup relations and ITT arguing that anxiety typically has detrimental effects. AUM examines communication as the primary effect of anxiety whereas ITT focuses on prejudice. Possible reconciliations between the theories are discussed along with directions for future research.
Further studies on the antinociceptive effects ofΔ acid

The antinociceptive effects ofΔ (THC-7-oic) acid have been investigated further with particular regard to the influence of certain experimental parameters in the hot plate test. These included the degree of the thermal stimulus, the nature of the vehicle and a possible role for copper in the response. A temperature effect similar to that seen with nonsteroidalantiinflammatory drugs (NSAIDs) was observed, 55° produced observable antinociception, however, at a surface temperature of 58°C no drug effect was seen. Non-aqeous vehicles such as peanut oil increased the potency of THC-7-oic acid. Finally, the substitution of purified water for tap water reduced,the drug response which could be partially restored by adding copper to the purified drinking water. An increase in the inhibitory effect when copper was added was also seenin vitro in a cell culture model where the acid reduced prostaglandin synthesis induced by THC. Our findings suggest that THC-7-oic acid probably acts by mechanisms similar to the NSAIDs and that the above mentioned experimental conditions can greatly influence the outcome of studies with this agent.
Retinal horizontal cell gap junctional conductance is modulated by dopamine through a cyclic AMP-dependent protein kinase

Abstract The action of many neuromodulators is mediated by intracellular second messengers such as cyclic AMP. In the retina, exogenously applied dopamine alters the conductance of gap junctions between cultured horizontal cells and this effect is mediated by cyclic AMP. However, it is not known how cyclic AMP modulates horizontal cell gap junction function. Here I report that cyclic AMP works by way of a cyclic AMP-dependent protein kinase. Cyclic AMP-dependent protein kinase injected into coupled horizontal cells from white bass (Roccus chrysops) rapidly and reversibly uncoupled the cells, mimicking the actions of dopamine. The threshold for the effect was between 0.06 and 0.03 microM. Injection of Walsh inhibitor of protein kinase [Walsh, D. A., Ashby, C. D., Gonzalez, C., Calkins, D., Fischer, E. H. & Krebs, E. G. (1971) J. Biol. Chem. 246, 1977-1985] blocked the effect of dopamine. Thus, the action of dopamine is to raise intracellular levels of cyclic AMP, which then activates a cyclic AMP-dependent protein kinase. Although not tested, it is likely that the cyclic AMP-dependent protein kinase phosphorylates a protein, possibly a gap junction protein, to alter conductance.
A simplified method for cyanogen bromide activation of agarose for affinity chromatography

Abstract Agarose can be activated by adding cyanogen bromide, dissolved in acetonitrile, to beads suspended in a solution of sodium carbonate. The necessity for manual titration and the use of a pH meter are thus eliminated. Activation for 1 min results in coupling capacities comparable to those reported for the titration method. The coupling capacity is influenced by the initial carbonate concentration and by the duration and temperature of the activation reaction. The coupling capacities of the activated gels are very reproducible.
RTP Modeling for CVD and Thermal Oxidation

A methodology for predicting the spatial and temporal distribution of film thickness is given for Chemical Vapor Deposition (CVD), and for thermal oxidation in Rapid Thermal Processor (RTP) systems, e.g. RTPCVD and RTO. The methodology is based on a wafer thermal model for the heat transfer to, from and within the wafer, a geometric ray trace algorithm to predict the radiant heat transfer from the lamps and reflectors to the wafer, a process model for the deposition or oxidation, and a gas flow model to predict the flow field in the RTP chamber. The CVD process is based on the Arrhenius deposition model, and thermal oxidation is based on a parallel diffusion model. The methodology has been validated by comparison of measured and predicted final film thickness from a cylindrical RTP system. The methodology is based on physical principles, with a minimum reliance on empirical relations and experimental data. As such it can be used for optimization of existing RTP designs and for the evaluation of proposed RTP configurations, such as new or novel lamp, reflector or chamber geometry.
Size-dependent predation on marine fish larvae by Ctenophores, Scyphomedusae, and Planktivorous fish

Size-dependent predation rates on marine fish larvae by the ctenophore Mnemiopsis leidyi, scyphomedusa Chrysaora quinquecirrha, and planktivorous fish Anchoa mitchilli were estimated via experiments in 3.2 m3 me-socosms. Predation rates on larvae of the goby Gobio-soma bosci were estimated in relation to 1) length of larval prey, 2) presence or absence of alternative < 1 mm zooplankton prey, and 3) a predator-prey interaction between the scyphomedusa and ctenophore. The consumption rate of larvae by the three predators generally declined as larval length increased. The ctenophore ate fewer (1.0 d-1 per predator) larvae than did the medusa (7.8 d-1 per predator) or bay anchovy (4.0 d-1 per predator), but it consumed larvae in all size classes tested (3.0–9.5 mm SL). Predation by bay anchovy and the medusa was more size-dependent: 3.0–5.0 mm larvae were most vulnerable. Fewer larvae were eaten by the ctenophore and bay anchovy when zooplankton alternative prey was available, but predation on larvae by the medusa was not influenced by alternative zooplankton prey. Consumption rate of fish larvae by the medusa was reduced 20–25% when the ctenophore was present as its alternative prey. An encounter-rate model was developed and its parameters estimated from the experimental results. Model simulations indicated that the relationship between larval size and vulnerability is dependent on size, swimming speed, and behavior of both predators and larvae, and that bigger or faster-growing fish larvae are not always less vulnerable to predation.
Adoption of fertility limitation in an American frontier population: an analysis and simulation of socio-religious subgroups.

Abstract This paper investigates a late nineteenth‐century fertility transition in a predominantly Mormon population of the western United States. A unique set of longitudinal data composed of 31,500 computerized family genealogies is drawn upon to examine a number of problems identified in reappraisals of fertility transition research (Caldwell, 1981; Freedman, 1979). Four subcohorts, differentiated by religious commitment and exposure to urban influences, are examined over the course of the transition. The study presents traditional analyses of subcohort CEB levels, period MTFR's, and m values (Coale and Trussell, 1974) and focuses on a macrosimulation of the fertility transition within the population (Bongaarts, 1976). Despite wide subcohort variation in cross‐sectional levels of fertility over time, simulation results suggest a similar absolute longitudinal decline in fertility levels, parity at which contraception was initiated, and maximum birth parities for all four subcohorts. The implications of ...
Clustering and variance maps for cryo-electron tomography using wedge-masked differences.

Cryo-electron tomography provides 3D imaging of frozen hydrated biological samples with nanometer resolution. Reconstructed volumes suffer from low signal-to-noise-ratio (SNR)1 and artifacts caused by systematically missing tomographic data. Both problems can be overcome by combining multiple subvolumes with varying orientations, assuming they contain identical structures. Clustering (unsupervised classification) is required to ensure or verify population homogeneity, but this process is complicated by the problems of poor SNR and missing data, the factors that led to consideration of multiple subvolumes in the first place. Here, we describe a new approach to clustering and variance mapping in the face of these difficulties. The combined subvolume is taken as an estimate of the true subvolume, and the effect of missing data is computed for individual subvolumes. Clustering and variance mapping then proceed based on differences between expected and observed subvolumes. We show that this new method is faster and more accurate than two current, widely used techniques.
Stimulation of Glucagon Secretion by Epinephrine in Man

Abstract To determine the influence of the adrenergic system on pancreatic alpha-cell function in man, effects of epinephrine on plasma glucagon levels were studied in 8 normal subjects. During infusion of epinephrine (6 μg/min for 1 hr) plasma glucagon rose progressively from a mean (± sem) level of 125 ± 9.1 pg/ml to a mean maximum of 180 ± 18.7 pg/ml, p < 0.01. Despite coexistent hyperglycemia, plasma insulin did not increase appreciably. Thus epinephrine stimulates glucagon secretion in man while inhibiting insulin release. The adrenergic system therefore appears to influence both pancreatic alphaand beta-cell function in man.
Origin of Stereochemistry in the α-Amino Acid Esters and Amides Generated from Optically Active Zirconaaziridine Complexes1

Methane elimination from ethylenebis(tetrahydroindenyl)(methyl)zirconium amides (R = alkyl or aryl, R‘ = aryl) (S,S)-26 gives a mixture of epimeric zirconaaziridines 25 and 30. When zirconaaziridin...
Corrections to coaxial Ge(Li) detector solid angle correction factors

Abstract This letter discusses additional corrections needed for solid angle correction factors for coaxial detectors.
ScOPT1 and AtOPT4 function as proton-coupled oligopeptide transporters with broad but distinct substrate specificities.

A group of OPTs (oligopeptide transporters) exclusively identified in plants and fungi are proposed to transport oligopeptides and derivatives of three to six amino acids in length, but their transport mechanisms and biological functions are poorly understood. We expressed the Saccharomyces cerevisiae (yeast) OPT ScOPT1 and five Arabidopsis thaliana AtOPTs in Xenopus laevis oocytes for two-electrode voltage-clamp studies. ScOPT1 produced inward currents in response to GSH or GSSG, the phytochelatin (PC) PC2 and oligopeptides including the tetrapeptide GGFL, but not KLGL. Inward currents were dependent on the external proton and substrate concentrations, with high affinity for both. This and the inward currents evoked by substrates with net negative charges showed that ScOPT1 is a proton-coupled transporter. ScOPT1 displayed highest apparent affinity for PC2, with small differences in the maximal current among substrates. Glutathione transport by any of the tested AtOPTs, including AtOPT6, was not detected in yeast growth complementation assays. With AtOPT4, initially only small KLGL-dependent currents were recorded in batches of oocytes showing high ScOPT1 expression. AtOPT4 expression was optimized by swapping the 5′-untranslated region with that of ScOPT1. AtOPT4 displayed a higher affinity for KLGL than ScOPT1 did for any peptide. AtOPT4-mediated KLGL transport was detectable at pH 5.0, but not at pH 6.0 or 7.0. Taken together, our results demonstrate that ScOPT1 and AtOPT4 are proton-coupled OPTs with broad but distinct substrate specificities and affinities.
The application of elliptic trigonometry to Laplace transformation and calculus

The concept of elliptic trigonometry was introduced by the author in a previous article [1]. The similarity between circular trigonometry and elliptic trigonometry in plane trigonometric functions and in elementary calculus has been derived. Also, the extension of elliptic trigonometry to Laplace transformation has been studied in this article. The relationships between circular and elliptic trigonometry are also introduced.
Limb profiles from low earth orbit

Recent satellite observations of the airglow in the 180-320 nm regime have provided detailed profiles of the noon, midnight, dawn and dusk limbs. Pitch maneuvers allowed spectrographs and imagers to scan the earth limbs through tangent altitudes from -100 km to +250 km. A UV imager observed the atmospheric emissions with an angular resolution of 10-4 radians/pixel, while a spectrograph simultaneously obtained UV spectra with a spectral resolution of 1 nm. The combination of these instruments allowed the vertical and spectral characterization of the earth limb emissions. Caused by solar fluorescence, the NO 7 band emissions dominate the noon, dusk, and dawn spectra, while the 02 Herzberg I emissions dominate the midnight limb. The peak in these emissions varies with solar zenith angle, with the peak emssion increasing in altitude with solar zenith angle. The measured intensities vary from 4 R at midnight at 200 km to 101 R at noon at 50 km.
How do treatment repeaters use the drug treatment system? An analysis of injection drug users in Massachusetts

This study explored common drug treatment utilization patterns in the first four types of treatments entered by injection drug users (IDUs) with multiple admissions. A Massachusetts longitudinal database with all entries to all licensed drug treatment programs was used. Treatment repeaters' admission patterns varied considerably. For the years 1997-2001, there were 2,500-3,000 IDUs new to the system each year who became treatment repeaters and who had more than 250 utilization patterns. Only approximately half of these repeaters followed the 10 most common utilization patterns. The most common pattern (for 30% of the population each year) was only entering detoxification two to four times; the only other common pattern (involving 4-8% of the population) was having entered methadone maintenance twice or having entered detoxification then methadone maintenance. Studies are needed to identify the extent to which the absence of a systematic pattern is caused by client, payment, or treatment setting and systems issues. A key implication is the need to develop policies that provide support for states to develop continuum-of-care models for their drug treatment systems.
Hysteresis in AC magnetic susceptibility and onset of field penetration in bulk granular YBa2Cu3Oy superconductors

Abstract Hysteresis in AC magnetic susceptibility of bulk granular YBa2Cu3Oy superconductors was investigated as a function of DC magnetic field and temperature. The pronounced irreversible behavior in the low field field regime allows a new approach to determine the onset of magnetic field penetration and an averaged lower critical field of the superconducting grains. A complete field-screening state in the intergranular region was observed for the first time. The temperature dependence of the lower critical field in both intra- and intergranular regions is consistent with the BCS pairing mechanism with a modified gap parameter 2Δ(0) = 7.0 kTc.