cssi/SciSciGPT-SciSciNet huggingface dataset:
Consistency and Symmetry

From the theoretical,mathematical point of view, even the fact that the evaluation of probability expresses somebody's opinion is then irrelevant. It is purely a question of studying it and saying whether it is coherent or not; i.e., whether it is free of, or affected by, intrinsic contradictions. In the same way, in the logic of certainty one ascertains the correctness of the deductions but not the accuracy of the factual data assumed as premises. Bruno de Finetti Theory of Probability I Symmetry arguments are tools of great power; therein lies not only their utility and attraction, but also their potential treachery. When they are invoked one may find, as did the sorcerer's apprentice, that the results somewhat exceed one's expectations. Sandy Zabell Symmetry and Its Discontents This chapter is a short introduction to the philosophy of inductive inference. After motivating the issues at stake, I'm going to focus on the two ideas that will be developed in this book: consistency and symmetry. Consistency is a minimal requirement for rational beliefs. It comes in two forms: static consistency guarantees that one's degrees of beliefs are not self-contradictory, and dynamic consistency requires that new information is incorporated consistently into one's system of beliefs. I am not going to present consistency arguments in full detail; my goal is, rather, to give a concise account of the ideas that underlie the standard theory of probabilistic learning, known as Bayesian conditioning or conditionalization , in order to set the stage for generalizing these ideas in subsequent chapters. Bayesian conditioning provides the basic framework for rational learning from factual propositions, but it does not always give rise to tractable models of inductive inference. In practice, nontrivial inductive inference requires degrees of beliefs to exhibit some kind of symmetry. Symmetries are useful because they simplify a domain of inquiry by distinguishing some of its features as invariant. In this chapter, we examine the most famous probabilistic symmetry, which is known as exchangeability and was studied extensively by Bruno de Finetti in his work on inductive inference.
Challenging the empire in empir(e)ical research: the question of speaking in music education

As an enterprise, academic research is in the business of knowledge production—a practice through which researchers continually engage in speaking for or about others. This paper explores the colon...
Effect of Aerobic Exercise Training and Essential Amino Acid Supplementation for 24 Weeks on Physical Function, Body Composition, and Muscle Metabolism in Healthy, Independent Older Adults: A Randomized Clinical Trial

BACKGROUND Essential amino acids (EAA) and aerobic exercise (AE) acutely and independently stimulate skeletal muscle protein anabolism in older adults. OBJECTIVE In this Phase 1, double-blind, placebo-controlled, randomized clinical trial, we determined if chronic EAA supplementation, AE training, or a combination of the two interventions could improve muscle mass and function by stimulating muscle protein synthesis. METHODS We phone-screened 971, enrolled 109, and randomized 50 independent, low-active, nonfrail, and nondiabetic older adults (age 72 ± 1 years). We used a 2 × 2 factorial design. The interventions were: daily nutritional supplementation (15 g EAA or placebo) and physical activity (supervised AE training 3 days/week or monitored habitual activity) for 24 weeks. Muscle strength, physical function, body composition, and muscle protein synthesis were measured before and after the 24-week intervention. RESULTS Forty-five subjects completed the 24-week intervention. VO2peak and walking speed increased (p < .05) in both AE groups, irrespective of supplementation type, but muscle strength increased only in the EAA + AE group (p < .05). EAA supplementation acutely increased (p < .05) muscle protein synthesis from basal both before and after the intervention, with a larger increase in the EAA + AE group after the intervention. Total and regional lean body mass did not change significantly with any intervention. CONCLUSIONS In nonfrail, independent, healthy older adults AE training increased walking speed and aerobic fitness, and, when combined with EAA supplementation, it also increased muscle strength and EAA-stimulated muscle protein synthesis. These increases occurred without improvements in muscle mass.
Intentional Online Discussions in Teacher Education

ABSTRACTThe goal of a creating civil discourse in teacher education deeply intersects with the ways that students interact in online discussions. However, as discussion shifts to online formats, digital misinformation is becoming widespread and threatens critical and civil communication as cognitive biases emerge in dialogue. The purpose of this case study research was to explore the participants' perceptions of growth and pitfalls while using the six essential elements of an online discussion typology developed as a pedagogical intervention to increase critical thinking and civility in discourse. The findings suggested that participants' responses in online discussions implied some cognitive biases and those participants engaged most often in discussions that were safe, comfortable, and familiar. Nevertheless, in their metacognitive reflections on the typology, participants demonstrated awareness of how these tendencies toward cognitive comfort shortchanged discussions and potential opportunities to deve...
The Biomechanics of Concussion: 60 Years of Experimental Research

Over the past 60 years, researchers across the planet have worked to understand the biomechanics of concussion and associated brain injuries. This chapter presents a summary of these efforts that begin with the human cadaver research performed in the 1950s and served as the foundation for the severity index and head injury criterion injury metrics. Following this research, experiments were performed on primates in order to quantify the injury physiology associated with concussion. More recently, the National Football League reconstructed concussive impacts and presented the first injury risk functions for concussion. The fourth dataset includes over two million head impacts measured with helmet instrumentation on volunteers playing football. By analyzing all of these data together, researchers have presented an array of injury risk functions for concussion that use both linear and rotational head acceleration parameters. Laboratory experiments utilize these risk functions to evaluate the performance of helmets and their ability to reduce the risk of concussion. Clinical studies have been performed that support and confirm the laboratory findings. The future of helmet testing will utilize a new impact system that more accurately reflects the head and neck kinematics the players experience during head impacts in sports.
The Hyper-β- and Hyperpre- β-lipoproteinemias

The physiologic role of VLDL and chylomicrons in the transport of triglyceride has been recognized for many years. The important role of LDL in the delivery of cholesterol and phospholipid to the cells of the body, however, has been brought into sharp focus only within the past several years. The studies by Goldstein and Brown have clearly established this role for LDL,1,2 and the disease a-β-lipoproteinemia provides a clinical testimonial to the consequences of defective cholesterol transport by LDL.3 The elegant studies by Goldstein and Brown have demonstrated, in fibroblasts, the presence of receptors which specifically recognize LDL and VLDL, and it is the absence of the high-affinity LDL receptor which characterizes the homozygous subject with familial hyper-β-lipoproteinemia.4,5 These individuals and their heterozygous kindred, who have a decrease but not an absence in the number of high-affinity receptors, have a resultant impairment in LDL catabolism with increased concentrations of plasma LDL. The major clinical consequence of this hyper-β-lipoproteinemia is the development of premature atherosclerosis.
A qualitative assessment of the smoking policies and cessation activities at smaller workplaces.

To reduce the negative consequences of smoking, workplaces have adopted and implemented anti-smoking initiatives. Compared to large workplaces, less research exists about these initiatives at smaller workplaces, which are more likely to hire low-wage workers with higher rates of smoking. The purpose of this study was to describe and compare the smoking policies and smoking cessation activities at small (20–99 employees) and very small (< 20 employees) workplaces. Thirty-two key informants coming from small and very small workplaces in Iowa completed qualitative telephone interviews. Data collection occurred between October 2016 and February 2017. Participants gave descriptions of the anti-smoking initiatives at their workplace. Additional interview topics included questions on enforcement, reasons for adoption, and barriers and facilitators to adoption and implementation. The data were analyzed using counts and content and thematic analysis. Workplace smoking policies were nearly universal (n = 31, 97%), and most workplaces (n = 21, 66%) offered activities to help employees quit smoking. Reasons for adoption included the Iowa Smokefree Air Act, to improve employee health, and organizational benefits (e.g., reduced insurance costs). Few challenges existed to adoption and implementation. Commonly cited facilitators included the Iowa Smokefree Air Act, no issues with compliance, and support from others. Compared to small workplaces, very small workplaces offered cessation activities less often and had fewer tobacco policy restrictions. This study showed well-established tobacco control efforts in small workplaces, but very small workplaces lagged behind. To reduce potential health disparities in smoking, future research and intervention efforts in tobacco control should focus on very small workplaces.
Weight gain trajectories during outpatient family‐based treatment for adolescents with anorexia nervosa

OBJECTIVE Given that weight gain patterns in adolescents receiving outpatient Family-Based Treatment (FBT) have not been characterized, the purpose of this study was to examine trajectories of weight gain in a group of adolescent patients with a restrictive eating disorder [e.g., anorexia nervosa (AN) and atypical AN] receiving FBT. This study also examined the association of patient characteristics with weight gain trajectories, including age, diagnosis, weight suppression, presenting BMI-for-age percentile, and eating pathology. METHOD Latent growth mixture modeling was used to identify distinct weight trajectories, as defined by change in BMI-for-age percentile, for 153 adolescents with AN or atypical AN, receiving FBT. RESULTS There were five distinct weight gain trajectory profiles for adolescents receiving FBT for a restrictive eating disorder. Younger age and greater weight suppression were associated with more rapid weight gain trajectories. A pattern of slow and consistent weight gain was associated with older age and less eating pathology. DISCUSSION There was considerable variability in weight gain trajectories in youth receiving outpatient FBT for a restrictive eating disorder. This suggests that patients' presenting information can be used to inform expectations regarding weight gain trajectories.
Extent of resection and role of adjuvant treatment in resected localized breast angiosarcoma

Localized breast angiosarcoma (LBA) is a rare condition with no prospective clinical trials guiding the management of afflicted patients. Management of LBA and the resulting outcomes on a nationwide scale has not been previously examined. The National Cancer Data Base (NCDB) from 2004 to 2014 identified resected LBA patients. Treatment patterns were compared between three time periods (2004–2007, 2008–2011, and 2012–2014). Demographic and tumor characteristics, as well as treatments received—extent of surgery and adjuvant therapies—were analyzed for association with overall survival after adjustment for covariates. 826 resected localized breast angiosarcoma patients were identified. Mastectomy was the most common surgical approach (86%); over 60% of patients did not receive adjuvant therapies after surgery. On multivariate analysis, tumor grade, tumor size, and surgical margins were associated with worse survival. Extent of surgery (mastectomy versus lumpectomy) and radiation therapy use were not associated with improved survival. Adjuvant chemotherapy was associated with improved survival in patients with primary tumors 5 cm and greater. The extent of surgery is not associated with improved survival in women with LBA, and patients may consider breast-conservation surgery. Adjuvant therapies are not associated with improved survival, with the exception of possible role of adjuvant chemotherapy in large primary tumors (5 cm or greater). Further clinical studies are needed to determine the impact of these treatments on local control, progression-free survival, and patients’ quality of life. Until then, the findings of our analysis will form basis for the multi-disciplinary discussion of management of women with LBA.
Cu(I)–O2 oxidation reactions in a fluorinated all-O-donor ligand environment

Investigation of Cu–O2 oxidation reactivity is important in biological and anthropogenic chemistry. Zeolites are one of the most promising Cu/O based oxidation catalysts for development of industrial-scale CH4 to CH3OH conversion. Their oxidation mechanisms are not well understood, however, highlighting the importance of the investigation of molecular Cu(I)–O2 reactivity with O-donor complexes. Herein, we give an overview of the synthesis, structural properties, and O2 reactivity of three different series of O-donor fluorinated Cu(I) alkoxides: K[Cu(OR)2], [(Ph3P)Cu(μ-OR)2Cu(PPh3)], and K[(R3P)Cu(pinF)], in which OR = fluorinated monodentate alkoxide ligands and pinF = perfluoropinacolate. This breadth allowed for the exploration of the influence of the denticity of the ligand, coordination number, the presence of phosphine, and K⋯F/O interactions on their O2 reactivity. K⋯F/O interactions were required to activate O2 in the monodentate-ligand-only family, whereas these connections did not affect O2 activation in the bidentate complexes, potentially due to the presence of phosphine. Both families formed trisanionic, trinuclear cores of the form {Cu3(μ3-O)2}3−. Intramolecular and intermolecular substrate oxidation were also explored and found to be influenced by the fluorinated ligand. Namely, {Cu3(μ3-O)2}3− from K[Cu(OR)2] could perform both monooxygenase reactivity and oxidase catalysis, whereas those from K[(R3P)Cu(pinF)] could only perform oxidase catalysis.
Coagulation Derangements in the ACS Patient: Understanding and Addressing Acute Coagulopathy

Coagulation abnormalities, in the acute care surgery (ACS) patients admitted to the intensive care unit (ICU), are frequent. Their knowledge is very important to reduce mortality and morbidity of the critically ill patients. The objective of this chapter is to provide concise and practical insights regarding pathophysiology, monitoring, and management of acute coagulopathy.
Big surprises from small supermassive black holes

The report of a 10,000 solar mass black hole in a dwarf galaxy provides new clues about how supermassive black holes form and grow with their host galaxies.
Eye Conditions in Women

Changes in vision can have significant impact on health and quality of life. Differences between women and men have been identified in the incidence of several eye conditions. Some of these differe...
RoboCOP: Jointly computing chromatin occupancy profiles for numerous factors from chromatin accessibility data

Abstract Chromatin is the tightly packaged structure of DNA and protein within the nucleus of a cell. The arrangement of different protein complexes along the DNA modulates and is modulated by gene expression. Measuring the binding locations and level of occupancy of different transcription factors (TFs) and nucleosomes is therefore crucial to understanding gene regulation. Antibody-based methods for assaying chromatin occupancy are capable of identifying the binding sites of specific DNA binding factors, but only one factor at a time. On the other hand, epigenomic accessibility data like ATAC-seq, DNase-seq, and MNase-seq provide insight into the chromatin landscape of all factors bound along the genome, but with minimal insight into the identities of those factors. Here, we present RoboCOP, a multivariate state space model that integrates chromatin information from epigenomic accessibility data with nucleotide sequence to compute genome-wide probabilistic scores of nucleosome and TF occupancy, for hundreds of different factors at once. We apply RoboCOP to MNase-seq data to elucidate the protein-binding landscape of nucleosomes and 150 TFs across the yeast genome. Using available protein-binding datasets from the literature, we show that our model predicts the binding of these factors genome-wide more accurately than existing methods.
The Case against Bailing Out the Airline Industry

Even if one is sympathetic to the idea of helping industries in times of crisis, the critical question to ask is, Are there more effective ways to resolve a company’s financial problems than a taxpayer-funded bailout? While the airline industry is always fast to request a bailout, such a bailout is rarely appropriate. As far as bailouts go, it is preferable to extend loans to firms than outright grants. Nevertheless, before the government considers any sort of bailout for the airlines, airlines should always first go through the bankruptcy process. As the United States has seen in the past, airline bankruptcy does not present any significant contagion risk to the economy. Airlines have often flown through bankruptcy successfully—American, Delta, and United have all done it—and airlines that each has merged with have done it as well, in some cases more than once, without jeopardizing airline operation or safety. And any help for workers should address the needs they face independently of which industry they work for. A hasty legislative package, pushed through in an emergency when the industry is weak and voters are panicked, should be kept as limited as possible. The risk is that operational reforms imposed under these circumstances will make the industry worse off once the crisis passes.
Responding to the Foreclosure Crisis in Appalachia: A Policy Review and Survey of Housing Counselors

Existing research on the foreclosure crisis tends to focus on national trends or on metropolitan areas. Few studies focus on rural areas, and none look at Appalachia in particular. Existing research on rural housing challenges suggests that rural communities face unique challenges in the wake of the foreclosure crisis due to capacity constraints, lack of qualified counselors in rural areas, and lack of funding availability. This study investigates the impact of existing policies upon Appalachian communities and households – analyzing whether communities suffering from widespread foreclosures lack the governmental and non-profit resources necessary to adequately utilize funding and other resources to respond to the crisis. We present findings from a survey of housing counselors serving the Appalachian region, which suggests that lack of federal funding is placing enormous strain on counseling agencies. These challenges often prevent them from getting distressed homeowners aid in a timely manner or help them to make modifications to their mortgages. Finally, we make policy and planning recommendations to target assistance to these and other rural and distressed communities suffering from foreclosures.
Development of a Segmented Scintillator for Decay Studies

Abstract A new detector was developed, which will enable future studies of neutron-rich isotopes. It is intended for use in fragmentation type experiments, which require segmentation in order to enable implantation-decay correlations. In addition, the detector requires good timing resolution for neutron time-of-flight experiments. A Position Sensitive Photo-Multiplier Tube (PSPMT) from Hamamatsu coupled with a fast pixelated plastic scintillator was used. Position localization of the nuclear radiation interaction with the detector has been achieved for energies up to 5 MeV. The detector provides sub-nanosecond time resolution through the use of a pulse-shape analysis algorithm, which is sufficient for time-of-flight experiments. The detector was tested with a laser pulserin order to simulate 1 GeV implantation energy and found to be capable to be used with high-energy heavy ions.
Survey of exposure to violence among the children of migrant and seasonal farm workers

Numerous children of migrant and seasonal farm workers live in rural areas of our country. The lifestyles and living conditions of farm workers place the children of these families at high risk for many health problems. However, few studies have focused on the emotional and behavioral well-being of these children. This study extends past research by examining the emotional and behavioral health of the children of farm workers in relation to a potentially risky environmental exposure, namely, exposure to violence. In this descriptive study, the extent of violence exposure, including being a witness to and a victim of violence, is examined among 8-11-year-old children of migrant and seasonal farm workers. Potential relationships between sociodemographic factors and violence exposure are examined, and associations between violence exposure and children's emotional and behavioral problems, and weapon carrying behavior are investigated. The results show that more than half of the study children had been exposed to violence, with 46 percent having witnessed violence among others and 19 percent having been the direct victims of violence. There was a fair degree of overlap between having witnessed violence and having been a victim of violence; 13 percent of all study children both witnessed and had been victims of violence, 33 percent only had witnessed violence, and 6 percent only had been victims of violence. Violence exposure was positively related to children's emotional problems, behavioral problems, and weapon carrying behavior. Language: en
Working memory impairment in probands with schizoaffective disorder and first degree relatives of schizophrenia probands extend beyond deficits predicted by generalized neuropsychological impairment

Objective Working memory impairment is well established in psychotic disorders. However, the relative magnitude, diagnostic specificity, familiality pattern, and degree of independence from generalized cognitive deficits across psychotic disorders remain unclear.
Pulmonary absorption of insulin mediated by tetradecyl-β-maltoside and dimethyl-β-cyclodextrin

Purpose. To determine if tetradecyl-β-maltoside (TDM) and dimethyl-β-cyclodextrin (DMβCD) enhance pulmonary absorption of insulin and to investigate if they do so by a reversible action on respiratory epithelium.
Detection of Masses in Digital Breast Tomosynthesis Mammography: Effects of the Number of Projection Views and Dose

We are developing a computer-aided detection (CAD) system for masses on digital breast tomosynthesis mammograms (DBT). A data set of DBT from patients was collected with informed consent using a GE prototype DBT system. The system has an Rh/Rh x-ray source and a CsI/a:Si detector, and acquires 21 projection view (PV) images over a 60o arc in 3o increments. The total dose of the 21 PVs is set to be about 1.5 times of the dose of a single screen-film mammogram. In this preliminary study, the DBTs from 50 patients are reconstructed with a simultaneous algebraic reconstruction technique (SART) in two conditions: one using all 21 PVs in 3o increments and the other 11 PVs in 6o increments. The latter therefore uses a subset of the PVs and about half the dose of the former. We compared the mass detection accuracy in these two sets of DBTs using the same CAD system. The system first identifies locations of mass candidates in the DBT volume using 3D gradient field analysis. The mass candidates are then segmented by 3D region growing. Morphological, gray level, and texture features are extracted from the segmented objects. A linear discriminant analysis (LDA) classifier with stepwise feature selection is designed by leave-one-out resampling. The output of the LDA is a mass likelihood score to which a decision threshold is applied and a free-response receiver operating characteristic (FROC) curve is generated. For the DBT set reconstructed with 21 PVs, the system achieved an 80% sensitivity at an average false positive (FP) rate of 1.52 per DBT volume. For the DBT set reconstructed with 11 PVs, the FP rate was 2.38 per breast at the same sensitivity. The difference in the FROC curves for the two conditions was statistically significant (p=0.03) by alternative FROC analysis. When the subset of 14 malignant cases was analyzed, the average FP rates were 0.87 and 1.11 per DBT volume at a sensitivity of 80% for the 21-PV and 11-PV conditions, respectively. The difference in the FROC curves for this smaller subset did not achieve statistical significance.
Malarial Resistance and Susceptibility, Genetics of

Resistance to malaria in humans, as well as drug and insecticide resistance by the malarial parasite and the mosquito that acts as its vector, respectively, is the result of adaptation by all three organisms. Characterization of the function and evolution of the genes underlying this resistance and susceptibility is paramount to our understanding of malarial treatment and eradication. Keywords: malaria; plasmodium; anopheles; anemia; parasite
Layer-controlled band gap and anisotropic excitons in few-layer black phosphorus

The authors report that the band structure of few-layer black phosphorous is anisotropic and the band gap increases with the decrease in number of staking layers. The optical absorption and excitonic effects are also anisotropic.
Active learning and compilation of higher order schema integration queries

After nearly 30 years, database integration remains the province of engineers and application developers. In an informal proof, Krishnamurthy, Litwin and Kent [KLK91] demonstrated that only higher order relational languages such as SchemaSQL and SchemaLog [LSS96] are general enough to concisely describe the merging of data from multiple heterogeneous sources. However, those languages are incrementally harder to program than SQL. A modern solution is to provide a GUI language with the same capabilities. However, a Query-by-Example (QBE) [Zloof77] type interface does not allow the unambiguous specification of higher order data integrating queries. We propose an architecture comprising three layers. In the middle layer, the user expresses the desired federated view through a QBE inspired user interface. Further learning proceeds via a sample selection method asking the user to validate examples of federated records. This interaction ends when the system is satisfied it has converged to the exact view definition the user intends. The bottom layer provides the execution mechanism for higher order data manipulations by compiling higher order relational definitions into first-order SQL programs. The top layer component of the architecture assists the learning algorithm by collecting meta-data and catalog statistics. Our primary contributions comprise a taxonomy examining trade-offs between complexity and completeness and identifying various classes of higher order relational data manipulations. The architecture delimits three separate challenges, which must be overcome in order to propose a solution. Our compilation for SchemaSQL proposes novel theoretical complexity guarantees. Type-based vertical partitioning of the meta-data ensures that the result can be properly optimized by existing SQL engines. Sample selection constraints specific to databases require the introduction of a third kind of instance label in the training set of our learner. We derive a new algorithm by modifying Mitchell's version spaces [Mitchell82] in order to handle this new kind of label. We prove that the modified algorithm preserves the original properties of version spaces and avoids the possibility of deadlock. We introduce a sample selection heuristic that converts catalog statistics into a classic inductive bias. Finally, we develop the Sphinx prototype, carry out experiments and demonstrate the system on an application.
Updates on sperm retrieval techniques

In the most extreme form of male infertility, the male partner is azoospermic. The advent of in vitro fertilization (IVF)-intracytoplasmic sperm injection (ICSI) has revolutionized our ability to treat azoospermia in both obstructive and non-obstructive cases. In obstructive azoospermia, it allows paternity without microsurgical reproductive tract reconstruction and also in cases where the reproductive tract is unreconstructable. In men with non-obstructive azoospermia, microdissection testicular sperm extraction (mTESE) has allowed us to retrieve sperm in men with exceedingly low sperm production. The introduction of microsurgery in sperm retrieval improves sperm yields and quality while minimizing the chance of surgical morbidity.
Drosophila Rae1 controls the abundance of the ubiquitin ligase Highwire in post-mitotic neurons

The highwire (Hiw)/DFsn ubiquitin ligase complex regulates synaptic morphology during development and axonal regeneration on injury. The authors identify Drosophila Rae1 as a component of the Hiw/DFsn complex and show that it controls Hiw protein abundance during synaptic development.
A parallel algorithm for Lees-Edwards boundary conditions

Abstract Accurate simulation of the transport properties of shearing systems via nonequilibrium molecular dynamics (NEMD) or nonequilibrium Brownian dynamics (NEBD) requires Lees-Edwards boundary conditions. In this note we present a data parallel algorithm and simulation results for the efficient parallelization of the Lees-Edwards boundary conditions.
Staphylococcal and Streptococcal Toxic Shock Syndrome

Definition of a Superantigen Toxic shock syndrome (TSS) is a life-threatening, multi-system disease characterized by rapid onset of fever, hypotension, and multi-organ failure. This disease entity has received considerable attention in the past 15 yr as a result of the appearance of menstrual TSS associated with Staphylococcus aureus and, most recently, with the global appearance of a streptococcal toxic shocklike syndrome (TSLS) associated with particular strains of StreptococcuS pyogenes, i.e., group A streptococci (GAS) (1). Although there is some evidence that viridans streptococci and groups B, C, F, and G streptococci cause TSLS (2), this discussion will be limited to S. aweuS and GAS, These two organisms produce protein exotoxins that have been shown to be associated with the development of TSS. These exotoxins are known as super-antigens because their interaction with the human immune system results in overstimulation of the normal response to a foreign antigen. The discovery of the mechanism of action of these exotoxins has defined TSS at the cellular level and has shed light on the complex regulatory pathways of our immune system. An understanding of the immune response to conventional antigens is necessary before superantigens can be adequately defined (3,4). Conventional foreign antigens encountered by the immune system are recognized by antigenpresenting cells (APC) that are primarily B cells, monocytes, and dendritic cells (Fig. 1). The antigens are internalized and processed into small peptides within the lysosomal compartments of the APC. The small peptides are transported to the APC membrane, where they form complexes with the major histocompatibility (MHC) class II molecules on the surface of these cells. This complex is recognized by T cells with receptors specific for the antigen/MHC complex. T-cell binding to antigen/MHC complexes initiates a series of events in the T cell and APC that result in the release of inflammatory cytokines, the regulatory messengers of the immune system. Cytokines such as interferon gamma (lFNy), interleukin 1 (IL-l), IL-6, and tumor necrosis factor alpha (ma) orchestrate activation and differentiation of immune cells, thereby allowing the body to respond to foreign invaders. T-cell binding to antigen/MHC complexes is highly specific and results in activation of only 0.0001% of the T cells in the body. This exquisite specificity is a result of the composition of the 01 and p chains of the T-cell receptor. These chains possess variable elements VP, Dp, Jp, Va, Ja that are encoded by many different genes within the human genome. Reassortment of these genes produces the vast repertoire of T-cell receptor specificities. Although there are innumerable combinations of a and p and regions, there are only about 25 major families of VP elements. This limited diversity of VP elements plays a key role in the excessive immune activation caused by super-antigens.
Die Toxine der Cyanobakterien: Neue bioaktive Verbindungen

Cyanobakterien produzieren eine Vielzahl bioaktiver Verbindungen, darunter potente Neuro-und Hepatotoxine. Am Beispiel der Biosynthese des Peptidtoxins Microcystin-LR konnte erstmals gezeigt werden, dass Cyanobakterien wie bestimmte andere Bakterien, Algen und Pilze fur die Biosynthese von Toxinen und anderen Sekundarmetaboliten riesige Proteinkomplexe verwenden, die aus modular aufgebauten Peptidsynthetasen und Polyketidsynthasen sowie modifizierenden Enzymen zusammengesetzt sind. Biochemiker und Molekularbiologen sind dabei, aus der Evolution von Peptidsynthetase- und Polyketidsynthasegenen zu lernen, wie einzelne Module und Domanen zu Enzymen mit neuen Eigenschaften zusammengefugt werden konnen. Ziel ist das Design neuer bioaktiver Verbindungen auf der Genebene. Cyanobakterien konnen fur diesen Zweck eine reiche Quelle von Enzymmodulen und Domanen mit interessanten Aktivitaten sein. Cyanobacteria produce numerous bioactive compounds including potent neuro- and hepatotoxins. The genes for the biosynthesis of microcystin, a hepatotoxic, cyclic heptapeptide, have been identified. Sequence analysis of these genes revealed that cyanobacteria ossess, like some other bacteria and lower eukaryotes, giant protein complexes consisting of peptide synthetases, olyketide synthases and tayloring enzymes involved in the biosynthesis of nonribosomal peptides and polyketides. Cyanobacteria represent a rich source of modules and domaines for the molecular design of new enzymes for the synthesis of bioactive compounds.
Effects of dominance on runaway sexual selection

Distinguishing among theories of sexual selection requires that one develop diagnostic predictions that can be tested in living systems. Recently, genetic studies of female species preferences in Drosophila supported the predictions of a model of sexual selection through pleiotropy with adap tive traits: preferences generally behaved as recessive characters. However, the dominance predic tions of female preferences resulting from runaway sexual selection have not been investigated. Here, I present an extension of previous simulation models of runaway sexual selection by varying the dominance of the female preference and incorporating genetic drift. I show that runaway sex ual selection is generally more likely to favor the evolution of dominant female preferences than recessive ones. Also, in contrast to the results of a previous study, dominant preferred male char acters spread more quickly by runaway sexual selection than recessive ones under some conditions. Overall, the predictions derived from this m...
Effect of ultra-violet irradiation on the electrical conductivity of zinc oxide single crystals.

Effect of Ultra-violet Irradiation on the Electrical Conductivity of Zinc Oxide Single Crystals
Pressure dependence of oxide growth rate on silicon and metal silicides

Abstract Si 2p photoemission was used to determine the relative oxidation rates for Si(111), Ru2Si3 and CoSi2. Samples were thermally oxidized at 750°C with oxygen pressures varying from 1 × 10−1 to 1 Torr. The results confirm that CoSi2 and Ru2Si3 oxidize faster than Si(111) at “hight” pressures, but reveal the surprising feature that the growth of SiO2 is faster on Si at pressures below 1 × 10−4 Torr.
Accelerator leakage measurements

The effects on shielding needs of a 15 Mv Mevatron-20 and a 10 Mv clinac 18 accelerator are discussed in the light of recent TVL measurements.(AIP)
Using surface characteristics to infer the permeability structure of an active fault zone

Abstract Studies of fault hydraulic architecture have shown faults to be spatially and temporally heterogeneous, with the potential to act as conduits, barriers, or a combination of conduit and barrier to subsurface fluid flow. Here we present a model for the distribution of permeability in an active normal fault based on a geostatistical analysis of 702 spring and ground temperature measurements. The temperatures were measured at the land surface along the trace of a normal fault that cross-cuts alluvium and weakly lithified sediments in the Alvord Basin of Oregon, USA. For flow parallel to the plane of the fault our analysis shows that the fault zone is dominated by broad areas of low to moderate permeability, interspersed with a number of spatially discrete, high-permeability flow paths. These observations are in agreement with conceptual models for faults in crystalline and well-lithified sedimentary rocks, but diverge from expectations for faults in alluvium and weakly lithified sediments. Our analysis demonstrates the potential for faults to develop hydraulic architectures intermediate between the idealized conceptual models currently available, and illustrates the need to test hypothesized behavior against observations in active systems.
Mixed Mode I/II fracture toughness of 2034 aluminum alloys

Abstract The mixed Mode I/II fracture toughnesses of two 2034 Al type alloys with different manganese contents were evaluated. The mixed Mode I/II fracture behavior of the two alloys was found to be different. Alloy 1 which had
How Do Batters Use Visual, Auditory, and Tactile Information About the Success of a Baseball Swing?

Bat/ball contact produces visual (the ball leaving the bat), auditory ( the “crack” of the bat), and tactile (bat vibration) feedback about the success of the swing. We used a batting simulation to investigate how college baseball players use visual, tactile, and auditory feedback. In Experiment 1, swing accuracy (i.e., the lateral separation between the point of contact and “sweet spot”) was compared for no feedback (N), visual alone, auditory alone, and tactile alone. Swings were more accurate for all single-modality combinations as compared to no feedback, and visual produced the greatest accuracy. In Experiment 2, the congruency between visual, tactile, and auditory was varied so that in some trials, the different modalities indicated that the simulated ball contacted the bat at different points. Results indicated that batters combined information but gave more weight to visual. Batting training manuals, which typically only discuss visual cues, should emphasize the importance of auditory and tactile ...
A novel zinc snap motif conveys structural stability to 3-methyladenine DNA glycosylase I.

Abstract The Escherichia coli 3-methyladenine DNA glycosylase I (TAG) is a DNA repair enzyme that excises 3-methyladenine in DNA and is the smallest member of the helix-hairpin-helix (HhH) superfamily of DNA glycosylases. Despite many studies over the last 25 years, there has been no suggestion that TAG was a metalloprotein. However, here we establish by heteronuclear NMR and other spectroscopic methods that TAG binds 1 eq of Zn2+ extremely tightly. A family of refined NMR structures shows that 4 conserved residues contributed from the amino- and carboxyl-terminal regions of TAG (Cys4, His17, His175, and Cys179) form a Zn2+ binding site. The Zn2+ ion serves to tether the otherwise unstructured amino- and carboxyl-terminal regions of TAG. We propose that this unexpected “zinc snap” motif in the TAG family (CX12–17HX∼150HX3C) serves to stabilize the HhH domain thereby mimicking the functional role of protein-protein interactions in larger HhH superfamily members.
The relationship between body weight, facial, and dental dimensions in a population of olive baboons (Papio cynocephalus anubis).

Abstract Correlation coefficients between dental dimensions, facial dimensions, and body weights for the adult males of a homogeneous troop of baboons were calculated. No significant correlations were found between mesial-distal tooth diameters and body weight. Facial dimensions also were generally not significantly correlated with body weight.
MicroRNAs in Stress Signaling and Human Disease

Disease is often the result of an aberrant or inadequate response to physiologic and pathophysiologic stress. Studies over the last 10 years have uncovered a recurring paradigm in which microRNAs (miRNAs) regulate cellular behavior under these conditions, suggesting an especially significant role for these small RNAs in pathologic settings. Here, we review emerging principles of miRNA regulation of stress signaling pathways and apply these concepts to our understanding of the roles of miRNAs in disease. These discussions further highlight the unique challenges and opportunities associated with the mechanistic dissection of miRNA functions and the development of miRNA-based therapeutics.
Edge and vertex insertion for a class of C 1 subdivision surfaces

Abstract Modeling with subdivision surfaces has been the subject of investigation by many researchers. To model most real-world objects, these subdivision schemes should have the ability to represent both sharp edges and vertices. In this paper we propose a new method for edge and vertex insertion on four-directional C 1 quadratic box spline surfaces. Edges and vertices may be inserted into an existing smooth surface and then deformed to have tangent plane discontinuities. The approach is easy to implement and can be generalized to work on other classes of subdivision schemes.
Safety monitoring and epidemiological surveillance of blood transfusion in the United States

Safety monitoring and epidemiological surveillance of blood transfusion in the United States is complex and involves government agencies and independent organizations. Several systems of control are in place nationwide to ensure that blood, blood components, and plasma derivatives meet prescribed standards. Control and surveillance of drugs that are biologics, which include human blood, blood components and plasma derivatives, are exercised by the Food and Drug Administration. Epidemiological surveillance involves several agencies and organizations that constitute a network capable of rapidly detecting unusual adverse events.
Figure of merit for near-velocity-matched traveling-wave modulators

We derive a relationship between the bandwidth and active length and a figure of merit for velocity- and near-velocity-matched lithium niobate traveling-wave electro-optic modulators. The figure of merit is given by the bandwidth per unit drive voltage squared and is independent of the length of the device. Alternatively, this figure of merit can be described by its inverse, which is proportional to the device's switching energy.
Magnetic resonance quantification of the myocardial perfusion reserve with a Fermi function model for constrained deconvolution.

The myocardial perfusion reserve, defined as the ratio of hyperemic and basal myocardial blood flow, is a useful indicator of the functional significance of a coronary artery lesion. Rapid magnetic resonance(MR)imaging for the noninvasive detection of a bolus-injected contrast agent as a MR tracer is applied to the measurement of regional tissue perfusion during rest and hyperemia, in patients with microvascular dysfunction. A Fermi function model for the distribution of tracer residence times in the myocardium is used to fit the MR signal curves. The myocardial perfusion reserve is calculated from the impulse response amplitudes for rest and hyperemia. The assumptions of the model are tested with Monte Carlo simulations, using a multiple path, axially distributed mathematical model of blood tissue exchange, which allows for systematic variation of blood flow, vascular volume, and capillary permeability. For a contrast-to-noise ratio of 6:1, and over a range of flows from 0.5 to 4.0 ml/min per g of tissue, the ratio of the impulse response amplitudes for hyperemic and basal flows is linearly proportional to the ratio of model blood flows, if the mean transit time of the input function is shorter than approximately 9 s. The uncertainty in the blood flow reserve estimates grows both at low ( ml/min/g ) and high (>3–4 ml/min/g ) flows. The predictions of the Monte Carlo simulations agree with the results of MR first pass studies in patients without significant coronary artery lesions and microvascular dysfunction, where the perfusion reserve in the territory of the left anterior descending coronary artery (LAD) correlates linearly with the intracoronary Doppler ultrasound flow reserve in the LAD (r=0.84), in agreement with previous PET studies.
Pricing the use of capital-intensive infrastructure over time and efficient capacity expansion: illustrations for electric transmission investment

Traditional economic theory provides a conundrum for pricing large, lumpy infrastructure investments: very different short- and long-run pricing prescriptions. Unless the facility is congested, efficient short run prices should only cover operating costs (short-run marginal cost, SMC); any higher price designed to also recover capital costs would risk inefficient under-utilization. However, if the facility becomes crowded, capital costs should be included in the calculation of user-fees since that burgeoning demand is likely to cause the construction of more capacity, and users should be confronted with the cost-consequences of their decisions. Once additional capacity is completed, however, and if because of the large size of the addition the facility is no longer congested, then price should once again fall to SMC. The resulting jagged pattern of prices offers little assurance to investors of capital cost-recovery without a government guarantee, and it may lead to schizophrenic behavior by both customers and potential suppliers. Just because the physical investment is lumpy, should the price pattern also be dichotomous or can a smoother transition be employed? By integrating the use of congestion fees that are based upon the external costs imposed by one user on all others prior to the construction of added capacity, and then by using the same congestion charge to gauge the “willingness-to-pay” for new capacity and to set an “opportunity-cost”-based benchmark for capital cost recovery afterward, a smoother sequence of prices can evolve. The capital cost recovery portion of these prices, whose magnitude is based upon the congestion eliminated, is premised on a long-run, dynamic view of markets and the transitions they can facilitate, and these cost-recovery adders can be combined with “peak-load-pricing” and the “inverse-elasticity” rule, for example, to improve efficiency and fairness over both space and time. The resulting price patterns can provide compatible incentives for all parties, and they complement several existing electricity system planning processes in those regions where congestion rents are already assessed for the use of transmission. The net effect could be similar to a sequential “real-options” analysis of efficient capacity expansion.