cssi/SciSciGPT-SciSciNet huggingface dataset:
Surface phase diagram for Cr 2 O 3 (0001): Ab initio density functional study

Surface phases of ${\mathrm{Cr}}_{2}{\mathrm{O}}_{3}(0001)$ as a function of ambient oxygen pressure and temperature were computed by ab initio density-functional theory for a solid surface. The surface can be $(1\ifmmode\times\else\texttimes\fi{}1)$ or $(\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3})$ Cr terminated, $(1\ifmmode\times\else\texttimes\fi{}1)$ O terminated, and $(1\ifmmode\times\else\texttimes\fi{}1)$ or $(\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3})$ $(\mathrm{O}=\mathrm{Cr})$ terminated. This is the first theory of the chromyl $(\mathrm{O}=\mathrm{Cr})$ termination. The terminations critically depend on the environment, i.e., on the temperature and on the ambient oxygen partial pressure. The first-principles phase diagram is compared with a substantial number of experimental observations of surface phases.
A Web-Based Treatment Decision Support Tool for Patients With Advanced Knee Arthritis: Evaluation of User Interface and Content Design.

Background: Data-driven surgical decisions will ensure proper use and timing of surgical care. We developed a Web-based patient-centered treatment decision and assessment tool to guide treatment decisions among patients with advanced knee osteoarthritis who are considering total knee replacement surgery. Objective: The aim of this study was to examine user experience and acceptance of the Web-based treatment decision support tool among older adults. Methods: User-centered formative and summative evaluations were conducted for the tool. A sample of 28 patients who were considering total knee replacement participated in the study. Participants’ responses to the user interface design, the clarity of information, as well as usefulness, satisfaction, and acceptance of the tool were collected through qualitative (ie, individual patient interviews) and quantitative (ie, standardized Computer System Usability Questionnaire) methods. Results: Participants were older adults with a mean age of 63 (SD 11) years. Three-quarters of them had no technical questions using the tool. User interface design recommendations included larger fonts, bigger buttons, less colors, simpler navigation without extra “next page” click, less mouse movement, and clearer illustrations with simple graphs. Color-coded bar charts and outcome-specific graphs with positive action were easiest for them to understand the outcomes data. Questionnaire data revealed high satisfaction with the tool usefulness and interface quality, and also showed ease of use of the tool, regardless of age or educational status. Conclusions: We evaluated the usability of a patient-centered decision support tool designed for advanced knee arthritis patients to facilitate their knee osteoarthritis treatment decision making. The lessons learned can inform other decision support tools to improve interface and content design for older patients’ use.
Current Modalities and Mechanisms Underlying Cardioprotection by Ischemic Conditioning

Ischemic preconditioning is a process which serves to mitigate reperfusion injury. Preconditioning of the heart can be achieved through natural, pharmacological, and mechanical means. Mechanical preconditioning appears to have the greatest chance of good outcomes while methods employing pharmacologic preconditioning have been largely unsuccessful. Remote ischemic preconditioning achieves a cardioprotective effect by applying cycles of ischemia and reperfusion in a distal limb, stimulating the release of a neurohumoral cardioprotective factor incited by stimulation of afferent neurons. The cardioprotective factor stimulates the reperfusion injury salvage kinase (RISK) and survivor activator factor enhancement (SAFE) signaling cascades in cardiomyocytes which promote cell survival by the expression of anti-apoptotic genes and inhibition of the opening of mitochondrial permeability transition pores. Clinical application of ischemic preconditioning involving targets in the RISK and SAFE signaling appears promising in the treatment of acute myocardial infarction; however, clinical trials have yet to demonstrate additional benefit to current therapy.
Measurement of the fracture toughness of a fiber-reinforced composite using the Brazilian disk geometry

A technique, using the Brazilian disk specimen, for measuring the fracture toughness of unidirectional fiber-reinforced composites, over the entire range of crack-tip mode mixities, was developed. The fracture toughness of a graphite/epoxy fiber-reinforced composite was measured, under both mode-I and mode-II loading conditions. We found that for certain material orientations the mode-II fracture toughness is substantially higher than the mode-I toughness. The complete dependence of the fracture toughness on the crack-tip mixity was determined for particular material orientations and the phenomenological fracture toughness curves were constructed. Using the Brazilian disk specimen, together with a hydraulic testing machine, the fracture toughness of the composite under moderate loading rates was measured. We observed that the mode-I fracture toughness was not sensitive to the loading rate at the crack tip, K, while the mode-II ‘dynamic’ fracture toughness increased approximately 50 percent over the quasi-static fracture toughness. A qualitative explanation of the dependency of fracture toughness on crack-tip loading rate is discussed. Finally, a mechanical fracture criterion, at the microscopic level, which governs the crack initiation under mixed-mode loading conditions is presented; these theoretical predictions closely follow the trend of experimental measurements.
Building and Maintaining a Citizen Science Network With Fishermen and Fishing Communities Post Deepwater Horizon Oil Disaster Using a CBPR Approach

When the Deepwater Horizon oil rig blew out in 2010, the immediate threats to productive deep water and estuarial fisheries and the region's fishing and energy economies were obvious. Less immediately obvious, but equally unsettling, were risks to human health posed by potential damage to the regional food web. This paper describes grassroots and regional efforts by the Gulf Coast Health Alliance: health risks related to the Macondo Spill Fishermen's Citizen Science Network project. Using a community-based participatory research approach and a citizen science structure, the multiyear project measured exposure to petrogenic polycyclic aromatic hydrocarbons, researched the toxicity of these polycyclic aromatic hydrocarbon compounds, and communicated project findings and seafood consumption guidelines throughout the region (coastal Louisiana, Mississippi, and Alabama). Description/analysis focuses primarily on the process of building a network of working fishermen and developing group environmental health literacy competencies.
The Involutory Laguerre Transition Matrix

It’s unusual for a matrix to be its own inverse. Indeed, a quick poll suggests that many mathematicians do not even know the name for a matrix with this curious property. (Pssst! It’s involutory.) ...
F-singularities under generic linkage

Abstract Let R = k [ x 1 , … , x n ] be a polynomial ring over a prefect field of positive characteristic. Let I be an equi-dimensional ideal in R and let J be a generic link of I in S = R [ u i j ] c × r . We describe the parameter test submodule of S / J in terms of the test ideal of the pair ( R , I ) when a reduction of I is a complete intersection or almost complete intersection. As an application, we deduce a criterion for when S / J has F-rational singularities in these cases. We also compare the F-pure threshold of ( R , I ) and ( S , J ) .
Pick Interpolation, II: Hilbert Space Proof

Our goal here is to prove the following part of Theorem 16.1 which, by the results of the last chapter, completes the proofs of Theorems 16.1, 16.3, and 16.4.
Resilience by design: A deep uncertainty approach for water systems in a changing world

Abstract Current water infrastructure designs and design processes are ill-suited to address deep uncertainties related to climate variability and change. Water systems increasingly exhibit fragility to extreme weather events and changing climate conditions. The concept of resilience offers a framework to improve water system design for uncertain futures by incorporating capabilities such as persistence, adaptability and transformability. Existing formalizations of resilience in engineering design, however, are dependent on assumptions of climate and hydrologic stationarity and of well-characterized uncertainty, rendering them obsolete relative to our current understanding of the uncertainties we face. In this paper, we use methods based on decision making under deep uncertainty to establish a methodology to design for the resilience of water systems. The formulation generates water system design options that provide resilience capabilities at least cost and specify the optimal choices for persistence, adaptability and transformability for performance over a wide range of possible futures. As it was developed for application beyond water systems, the Resilience by Design is a generalizable approach offering important new methods of planning and managing for the resilience of critical infrastructure.
Our hunter-gatherer future: Climate change, agriculture and uncivilization

Abstract For most of human history, about 300,000 years, we lived as hunter gatherers in sustainable, egalitarian communities of a few dozen people. Human life on Earth, and our place within the planet’s biophysical systems, changed dramatically with the Holocene, a geological epoch that began about 12,000 years ago. An unprecedented combination of climate stability and warm temperatures made possible a greater dependence on wild grains in several parts of the world. Over the next several thousand years, this dependence led to agriculture and large-scale state societies. These societies show a common pattern of expansion and collapse. Industrial civilization began a few hundred years ago when fossil fuel propelled the human economy to a new level of size and complexity. This change brought many benefits, but it also gave us the existential crisis of global climate change. Climate models indicate that the Earth could warm by 3°C-4 °C by the year 2100 and eventually by as much as 8 °C or more. This would return the planet to the unstable climate conditions of the Pleistocene when agriculture was impossible. Policies could be enacted to make the transition away from industrial civilization less devastating and improve the prospects of our hunter-gatherer descendants. These include aggressive policies to reduce the long-run extremes of climate change, aggressive population reduction policies, rewilding, and protecting the world’s remaining indigenous cultures.
Wntless regulates lipogenic gene expression in adipocytes and protects against diet-induced metabolic dysfunction.

Abstract Objective Obesity is a key risk factor for many secondary chronic illnesses, including type 2 diabetes and cardiovascular disease. Canonical Wnt/β-catenin signaling is established as an important endogenous inhibitor of adipogenesis. This pathway is operative in mature adipocytes; however, its roles in this context remain unclear due to complexities of Wnt signaling and differences in experimental models. In this study, we used novel cultured cell and mouse models to investigate functional roles of Wnts secreted from adipocytes. Methods We generated adipocyte-specific Wntless (Wls) knockout mice and cultured cell models to investigate molecular and metabolic consequences of disrupting Wnt secretion from mature adipocytes. To characterize Wls-deficient cultured adipocytes, we evaluated the expression of Wnt target and lipogenic genes and the downstream functional effects on carbohydrate and lipid metabolism. We also investigated the impact of adipocyte-specific Wls deletion on adipose tissues and global glucose metabolism in mice fed normal chow or high-fat diets. Results Many aspects of the Wnt signaling apparatus are expressed and operative in mature adipocytes, including the Wnt chaperone Wntless. Deletion of Wntless in cultured adipocytes results in the inhibition of de novo lipogenesis and lipid monounsaturation, likely through repression of Srebf1 (SREBP1c) and Mlxipl (ChREBP) and impaired cleavage of immature SREBP1c into its active form. Adipocyte-specific Wls knockout mice (Wls-/-) have lipogenic gene expression in adipose tissues and isolated adipocytes similar to that of controls when fed a normal chow diet. However, closer investigation reveals that a subset of Wnts and downstream signaling targets are upregulated within stromal-vascular cells of Wls-/- mice, suggesting that adipose tissues defend loss of Wnt secretion from adipocytes. Interestingly, this compensation is lost with long-term high-fat diet challenges. Thus, after six months of a high-fat diet, Wls-/- mice are characterized by decreased adipocyte lipogenic gene expression, reduced visceral adiposity, and improved glucose homeostasis. Conclusions Taken together, these studies demonstrate that adipocyte-derived Wnts regulate de novo lipogenesis and lipid desaturation and coordinate the expression of lipogenic genes in adipose tissues. In addition, we report that Wnt signaling within adipose tissues is defended, such that a loss of Wnt secretion from adipocytes is sensed and compensated for by neighboring stromal-vascular cells. With chronic overnutrition, this compensatory mechanism is lost, revealing that Wls-/- mice are resistant to diet-induced obesity, adipocyte hypertrophy, and metabolic dysfunction.
Policy specific moods disconnect income inequality and government redistribution

The competing arguments of “unequal democracy” and “dynamic democracy” highlight the puzzle of why there has been unabated economic inequality in the U.S. over the past few decades. This study addr...
A Conceptual Definition of Quality of Life for People Living with an Implanted Destination Therapy Left Ventricular Assist Device

Purpose People with advanced heart failure experience persistently severe symptoms with increasingly impaired capacity and quality of life. Treatment options beyond palliative care are limited to heart transplantation or implantation with a mechanical pump that replaces the weakened heart's function. The left ventricular assist device (LVAD) serves as a temporary bridge to transplant or bridge to recovery, or a permanent replacement as destination therapy (DT). While DT-LVAD recipients initially accept the device to extend life, there is a gap in understanding how DT-LVAD recipients define a life worth living, and how nursing and the health care team can help reach that goal. This study's purpose is to determine the conceptual definition of “quality of life” in people with a DT-LVAD. Methods A grounded theory study was conducted using a theoretical sample and open, selective and theoretical coding processes within the constant comparison method. Theoretical saturation was reached with 11 participants (age 32-79 years). Results Normalizing emerged as the basic social process. Participants reported that a life supported by battery-powered equipment is still a normal, human experience. A process of acceptance and adjustment occurred to Normalize a machine-dependent life. Although extending life was the original LVAD objective, recipient goals and needs evolved over time. Dependence on a machine to extend life did not replace the need for a life worth living. The conceptual definition of quality of life when living with a DT-LVAD emerged as: I am able to live my life and do what I want, with some adjustments. Conclusion This conceptual definition of quality of life from the DT-LVAD recipient perspective enhances the health care team's understanding and ability to improve DT-LVAD recipient lives. Life with an LVAD is not simply about survival; it is survival of quality that makes a difference and defines success.
A HIGH-RESOLUTION HUBBLE SPACE TELESCOPE STUDY OF APPARENT LYMAN CONTINUUM LEAKERS AT z ∼ 3

We present U_(336)V_(606)J_(125)H_(160) follow-up Hubble Space Telescope (HST) observations of 16 z ~ 3 candidate Lyman continuum (LyC) emitters in the HS1549+1919 field. With these data, we obtain high spatial-resolution photometric redshifts of all sub-arcsecond components of the LyC candidates in order to eliminate foreground contamination and identify robust candidates for leaking LyC emission. Of the 16 candidates, we find one object with a robust LyC detection that is not due to foreground contamination. This object (MD5) resolves into two components; we refer to the LyC-emitting component as MD5b. MD5b has an observed 1500 A to 900 A flux-density ratio of (F_(UV)/F_(LyC)_(obs) = 4.0 ± 2.0, compatible with predictions from stellar population synthesis models. Assuming minimal IGM absorption, this ratio corresponds to a relative (absolute) escape fraction of f_(esc,rel)^(MD5b) = 75%–100% f_(esc,abs)^(MD5b) = 14%–19%). The stellar population fit to MD5b indicates an age of ≾50 Myr, which is in the youngest 10% of the HST sample and the youngest third of typical z ~ 3 Lyman break galaxies, and may be a contributing factor to its LyC detection. We obtain a revised, contamination-free estimate for the comoving specific ionizing emissivity at z = 2.85, indicating (with large uncertainties) that star-forming galaxies provide roughly the same contribution as QSOs to the ionizing background at this redshift. Our results show that foreground contamination prevents ground-based LyC studies from obtaining a full understanding of LyC emission from z ~ 3 star-forming galaxies. Future progress in direct LyC searches is contingent upon the elimination of foreground contaminants through high spatial-resolution observations, and upon acquisition of sufficiently deep LyC imaging to probe ionizing radiation in high-redshift galaxies.
Using GANs with adaptive training data to search for new molecules

The process of drug discovery involves a search over the space of all possible chemical compounds. Generative Adversarial Networks (GANs) provide a valuable tool towards exploring chemical space and optimizing known compounds for a desired functionality. Standard approaches to training GANs, however, can result in mode collapse, in which the generator primarily produces samples closely related to a small subset of the training data. In contrast, the search for novel compounds necessitates exploration beyond the original data. Here, we present an approach to training GANs that promotes incremental exploration and limits the impacts of mode collapse using concepts from Genetic Algorithms. In our approach, valid samples from the generator are used to replace samples from the training data. We consider both random and guided selection along with recombination during replacement. By tracking the number of novel compounds produced during training, we show that updates to the training data drastically outperform the traditional approach, increasing potential applications for GANs in drug discovery.
Predicting thermal excursions during in situ oxidative regeneration of packed bed catalytic fast pyrolysis catalyst

Ex situ catalytic fast pyrolysis (CFP) uses a secondary reactor to upgrade biomass pyrolysis vapors to stabilized CFP oils with reduced oxygen content. In one configuration, the secondary reactor is operated as a packed-bed swing reactor system which allows coke-deactivated beds to be decarbonized in situ while other beds remain online for vapor upgrading. In situ decarbonization must be done carefully to avoid irreversible deactivation and/or physical degradation of catalyst pellets. Given that packed bed reactors are well known to have poor heat transfer characteristics, this is a critical issue impacting scaleability and commercial viability of the technology. To predict thermal excursions during regeneration, finite element computational models have been built to assist in scaling up oxidative decarbonization of a Pt/TiO2 CFP catalyst (0.5 mm spheres) from a bench scale packed bed with 100 g of catalyst to a pilot scale packed bed with 2 kg of catalyst and internal cooling tubes. Based on transient measurements of outlet temperature and effluent CO2 concentration, and using an assumed coke profile and activation energy, this paper demonstrates that specific combinations of effective thermal conductivity and wall heat transfer coefficient can fit bench scale oxidative regeneration data equally well. For the upscaled 2 kg bed, four bench-scale “best fit” parameter pairs give different predictions for location and magnitude of thermal excursions, with the maximum computed bed temperature gradients ranging from 30 °C cm−1 to as high as 3000 °C cm−1. The larger the fraction of heat removal by conduction through the cooling tubes, the greater the differences between the parameter pairs. The modelling results presented in this paper cast doubt on the industrial viability of the proposed combination of catalyst, bed and regeneration process, and point to the need for alternate reactor designs. However, there is considerable uncertainly in some of the key model parameters. The reliability of model predictions can be increased by adding more temperature measurements at key bed locations, testing additional variations in process conditions, performing careful bed dissections to determine the true coke profile, and perhaps most importantly, directly measuring the effective thermal conductivity of the catalyst pellets.
Teaching Performance, Service, and Scholarship: The Rewarding of U.S. Media and Communication Faculty Members’ Teaching in Tenure and Promotion Documents:

University reward systems (i.e., tenure and promotion standards) can shape educators’ behaviors and dedication to teaching. This study contributes to knowledge by conceptually mapping teaching eval...
Abstract P175: Predicting Healthy Arterial Aging Versus Premature Atherosclerosis In Young Adults: The Bogalusa Heart Study

Introduction: Early differentiation of healthy arterial aging versus premature atherosclerosis is important for optimal atherosclerotic cardiovascular disease (ASCVD) risk stratification and preven...
Effects of Self-Regulated Physical Activity in Premature Infants on Bone Density and Length of Stay: A Pilot Study.

Importance Premature infants are not prepared developmentally, physically, or cognitively with the multiple survival skills of the typical newborn. Objective To determine whether physical activity generated spontaneously by premature infants stretching against the resistance of "prepod" garments is as effective as exercises provided by therapists in slowing bone density loss. Design Preterm very low birth weight infants were placed in two nonrandomized parallel groups according to birth age. Setting Infants routinely started in a traditional intense intervention setting and graduated to a special care section with private rooms that allowed parents to remain with their child. Participants Healthy infants without medical complications, born between 28 and 32 wk postmenstrual age. Intervention The control group received traditional exercises. The experimental group wore a prepod almost 24 hr a day. Outcomes and Measures: An ultrasound of the tibia was obtained at 31 to 32 wk and 4 wk later. Weight gain, head circumference growth, and length of stay (LOS) were also measured. Results Although not statistically significant, the ultrasound results showed that the prepod group had less loss of bone density than the traditional therapy exercise group. The desired outcome was for pods to be as effective at reducing bone loss as traditional exercise, so the results exceeded expectations. The unexpected, and more notable, finding was a striking drop in LOS for the prepod group. Conclusions and relevance Spontaneous exercise by premature infants decreases bone loss and LOS. Better bone health and increased developmental maturity increase the chances of a positive developmental outcome and save the hospital significant expense. What This Article Adds: The prepod is a simple, cost-effective, noninvasive treatment tool occupational therapy practitioners can use to support a premature infant's development. This study has considerable potential to affect how infants are served, both developmentally and financially.
Efficient encoding scheme for ultra-fast flash ADC

We propose an efficient encoding scheme to be designed using the robust principle of programmable logic arrays (PLA) for an ultra-fast flash analog to digital converter (ADC). High-speed operation in the MHz-GHz range is the major goal of flash ADC design. A high-speed ADC needs a fast comparator, a high-speed encoder, and a fast sample and hold (S-H) circuit. These three areas of high-speed ADC design require equally careful attention. Technological advancement has produced superior high-speed comparators. The speed of encoders has been dealt with mostly on the algorithmic part. We propose a CMOS based encoder design to be integrated with a CMOS based high-speed comparator for system-on-chip (SoC). Depending on the availability of high-speed comparators, our design exploits the design of the comparator for the benefit of speeding up the encoder.
The discovery of the principles of reinforcement, extinction, generalization, and differentiation of conditional reflexes in Pavlov's laboratories.

The discovery of reinforcement, extinction, generalization, and differentiation with the conditional reflex method in Pavlov’s laboratories is described. Modern American introductory texts show that contemporary understanding of the experimental work on conditioning in Pavlov’s laboratories is derived from a 1927 English translation of Pavlov’s lectures on the conditional reflexes. The lectures present the discoveries topically, not chronologically. In contrast, this article presents a chronological account of the contributions of S. G. Vul’fson, I. F. Tolochinov, and B. P. Babkin, which led to the conceptualization of reinforcement and extinction, and the work of V. N. Boldyrev and N. A. Kashereninova, which led to the formulation of the concepts of generalization and differentiation. This historical approach avoids giving the impression that the development of the Pavlovian paradigm was a highly systematic pursuit.
Integrated 3D view of postmating responses by the Drosophila melanogaster female reproductive tract, obtained by micro-computed tomography scanning

Physiological changes in females during and after mating are triggered by seminal fluid components in conjunction with female-derived molecules. In insects, these changes include increased egg production, storage of sperm, and changes in muscle contraction within the reproductive tract (RT). Such postmating changes have been studied in dissected RT tissues, but understanding their coordination in vivo requires a holistic view of the tissues and their interrelationships. Here, we used high-resolution, multiscale micro-computed tomography (CT) scans to visualize and measure postmating changes in situ in the Drosophila female RT before, during, and after mating. These studies reveal previously unidentified dynamic changes in the conformation of the female RT that occur after mating. Our results also reveal how the reproductive organs temporally shift in concert within the confines of the abdomen. For example, we observed chiral loops in the uterus and in the upper common oviduct that relax and constrict throughout sperm storage and egg movement. We found that specific seminal fluid proteins or female secretions mediate some of the postmating changes in morphology. The morphological movements, in turn, can cause further changes due to the connections among organs. In addition, we observed apparent copulatory damage to the female intima, suggesting a mechanism for entry of seminal proteins, or other exogenous components, into the female’s circulatory system. The 3D reconstructions provided by high-resolution micro-CT scans reveal how male and female molecules and anatomy interface to carry out and coordinate mating-dependent changes in the female’s reproductive physiology.
Structural and electrical properties of magnetic ceramics of Co1−xCuxFe2O4 spinel nanoferrites

Magnetic ceramics of the type of spinel nanoferrites of Co1−xCuxFe2O4 with Cu concentrations of x = 0·00, 0·25, 0·50, 0·75 and 1·00 were prepared by chemical co-precipitation method. X-ray diffraction results confirmed the formation of a single spinel ferrite structure with crystallite size in the range of 20–63 nm. Scanning electron microscopy and EDS were used to study the morphological and compositional changes taking place with varying Cu concentration. DC electrical resistivity, activation energy and drift mobility are strongly influenced by both Cu concentration and temperature. Resistivities of the prepared magnetic ceramics were found to decrease with the increase in Cu concentration to follow Verwey mechanism. The semiconductor behaviour of the prepared nanoparticles was confirmed from the standard Arrhenius relation of resistivity versus temperature. The dielectric constants were measured in the frequency range of 100 Hz–3·0 MHz and are explained by the Maxwell–Wagner interfacial type of polaris...
Formation of Triplet Positron-helium Bound State by Stripping of Positronium Atoms in Collision with Ground State Helium

Formation of triplet positron-helium bound state by stripping of positronium atoms in collision with ground state helium JOSEPH DI RlENZI, College of Notre Dame of Maryland, RICHARD J. DRACHMAN, NASA/Goddard Space Flight Center - The system consisting of a positron and a helium atom in the triplet state e(+)He(S-3)(sup e) was conjectured long ago to be stable [1]. Its stability has recently been established rigorously [2], and the values of the energies of dissociation into the ground states of Ps and He(+) have also been reported [3] and [4]. We have evaluated the cross-section for this system formed by radiative attachment of a positron in triplet He state and found it to be small [5]. The mechanism of production suggested here should result in a larger cross-section (of atomic size) which we are determining using the Born approximation with simplified initial and final wave functions.
Inhibition of IL-12 Production in Human Monocyte-Derived Macrophages by TNF

IL-12 is a pivotal cytokine that links the innate and adaptive immune responses. TNF-alpha also plays a key role in orchestrating inflammation and immunity. The reciprocal influence of these two inflammatory mediators on each other may have significant impact on the cytokine balance that shapes the type and extent of immune responses. To investigate the relationship between TNF-alpha and IL-12 production, we analyzed the effects of exposure of human monocyte-derived macrophages to TNF-alpha on LPS- or Staphylococcus aureus-induced IL-12 production in the presence or absence of IFN-gamma. TNF-alpha is a potent inhibitor of IL-12 p40 and p70 secretion from human macrophages induced by LPS or S. aureus. IL-10 is not responsible for the TNF-alpha-mediated inhibition of IL-12. TNF-alpha selectively inhibits IL-12 p40 steady-state mRNA, but not those of IL-12 p35, IL-1alpha, IL-1beta, or IL-6. Nuclear run-on analysis identified this specific inhibitory effect at the transcriptional level for IL-12 p40 without down-regulation of the IL-12 p35 gene. The major transcriptional factors identified to be involved in the regulation of IL-12 p40 gene expression by LPS and IFN-gamma, i.e., c-Rel, NF-kappaB p50 and p65, IFN regulatory factor-1, and ets-2, were not affected by TNF-alpha when examined by nuclear translocation and DNA binding. These data demonstrate a selective negative regulation on IL-12 by TNF-alpha, identifying a direct negative feedback mechanism for inflammation-induced suppression of IL-12 gene expression.
Nuclease hypersensitivity in the β-globin gene region of K562 cells

We have investigated chromatin structure in the beta-globin gene region of the K562 human erythroleukemic cell line by using S1 and DNase I nuclease sensitivity assays. Despite the lack of beta-globin gene expression in these cells, we find nuclease-hypersensitive sites to these enzymes in its 5' and 3' flanking regions in K562 chromatin. This result is in contrast to previous reports in which no hypersensitive sites were found in the immediate vicinity of this gene. In the 3' region, one major hypersensitive site at 0.9 kpb 3' and three minor hypersensitive sites at 0.7 kbp, 0.5 kbp 3' and 0.2 kbp 5' of the polyadenylation site were observed; these sites are very similar to those found in fetal liver and adult bone marrow cells in which the beta-globin gene is expressed. We find hypersensitive sites to both enzymes in the 5' region of the beta-globin gene: a major site 0.8 kbp 5' to the cap site, and two minor sites 1.2 and 1.5 kbp 5' to the cap site. The -0.8 kbp site is also present in plasmids containing the beta-globin gene. Our results suggest that the lack of beta-globin gene expression may be related to the lack of hypersensitivity sites in the immediate (150 bp) 5' flanking region of the beta-globin gene, as occurs in other active globin genes.
Hα Imaging of Early-Type Sa-Sab Spiral Galaxies. II. Global Properties

New results, based on one of the most comprehensive Hα imaging surveys of nearby Sa–Sab spirals completed to date, reveals early-type spirals to be a diverse group of galaxies that span a wide range in massive star formation rates. While the majority of Sa–Sab galaxies in our sample are forming stars at a modest rate, a significant fraction (~29%) exhibit star formation rates greater than 1 M⊙ yr-1, rivaling the most prolifically star-forming late-type spirals. A similar diversity is apparent in the star formation history of Sa–Sab spirals as measured by their Hα equivalent widths. Consistent with our preliminary results presented in the first paper in this series, we find giant H II regions [L(Hα) ≥ 1039 ergs s-1] in the disks of ~37% of early-type spirals. We suspect that recent minor mergers or past interactions are responsible for the elevated levels of Hα emission and, perhaps, for the presence of giant H II regions in these galaxies. Our results, however, are not in total agreement with the Hα study of Kennicutt & Kent, who did not find any early-type spirals with Hα equivalent widths >14 A. A close examination of the morphological classification of galaxies, however, suggests that systematic differences between the Revised Shapley-Ames Catalog and the Second Reference Catalogue may be responsible for the contrasting results.
The crystal structure of a cyclodecabis[1,2,3]selenadiazole

4,5,6,10,11,12-hexahydrocyclodeca[1,2-d∶6,7-d′]bis[1,2,3]selenadiazole, C10H12N4Se2, crystallizes in triclinic space group P\(\bar 1\) witha=5.4625(3),b=7.2091(4),c=8.3122(6) A, α=65.313(5), β=77.476(5), γ=77.442(5)°,V=287.35(4) A3,Z=1. The structure was refined toR=0.031 andRw=0.030 for 2018 observed reflections. The molecule lies on an inversion center. The cyclodecadiene ring adopts an elongated chair conformation. The near-zero torsion angle of the elongated chair lies at the ring-fusion bonds, with a magnitude of 2.9(3)°. The five atoms of the selenadiazole ring exhibit maximum deviation 0.005(2) A from planarity, with the adjacent carbon atoms lying respectively 0.020(2) and 0.059(2) A to the same side of this plane. The torsion angles about the bonds comprising the sides of the elongated chair vary in magnitude from 61.0(2)° to 55.7(2)°. The cyclodecadiene C=C bond lengths are 1.368(2) A. The selenium-carbon bond length is 1.850(2) A. The Se−N distance is quite long, 1.888(2) A.
E2A proteins maintain the hematopoietic stem cell pool and promote the maturation of myelolymphoid and myeloerythroid progenitors

Hematopoiesis is a tightly controlled process maintained by a small pool of hematopoietic stem cells (HSCs). Here, we demonstrate that the LT-HSC, MPP, premegakaryocytic/erythroid, Pre CFU-E, Pre GM, MkP, and granulocyte-macrophage compartments were all significantly reduced in E2A-deficient bone marrow. Despite a severe depletion of erythroid progenitors, the erythrocyte and megakaryocyte compartments were equivalent in E2A-deficient bone marrow as compared with wild-type mice. E2A-deficient HSCs also failed to efficiently maintain the HSC pool on serial transplantation, and we demonstrate that the E2A proteins regulate cell cycle progression of HSCs by regulating the expression of p21Cip1, p27Kip1, and the thrombopoietin receptor, known regulators of HSC self-renewal activity. Based on these observations, we propose that the E2A proteins promote the developmental progression of the entire spectrum of early hematopoietic progenitors and to suppress an erythroid specific program of gene expression in alternative cell lineages. Last, the data mechanistically link E2A, cell cycle regulators, and the maintenance of the HSC pool in a common pathway.
Muon-Pair Production in High-Energy Proton-Proton Collisions

Using a current-algebra sum rule derived from an equal-time commutator between charge densities, we have set a lower bound on the muon-pair production cross sections. In spite of the fact that our estimate is conservative, the lower bound turns out to be very large at energies larger than \ensuremath{\sim}100 GeV ($\ensuremath{\gtrsim}0.50\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}30}$ ${\mathrm{cm}}^{2}$ at 500 GeV, the maximum available energy at the National Accelerator Laboratory). Comparing it with recent experimental data at lower energies, we predict that the muon-pair production cross section will keep increasing until it turns over owing to higher-order electromagnetic interactions through unitarity.
Structural Verification of the Redesigned Space Shuttle Bipod Foam Closeout

This document outlines the structural verification approach for the Space Shuttle External Tank Forward Bipod Foam Closeout. Due to the Space Shuttle Columbia accident, debris has become a major concern. The intent of the structural verification is to ensure that any debris shed from the bipod is within acceptable limits. Since cohesive failure due to internal defects was identified as the most likely cause of the STS-107 bipod ramp foam failure, verification for this failure mode receives particular emphasis. However, all failure modes for TPS are considered and appropriate verification rationale is developed for each failure mode. Figure 1 depicts the structural verification of a production design where analysis and test are the primary methods of verification. It can be seen that the successful completion of structural verification is dependent on three main areas: 1. Production process control and quality assurance must ensure that test articles and/or analytical models are representative of (or conservatively envelope) production hardware in terms of geometry, materials and processing. Variability and defects must be considered. 2. Flight environments must be sufficiently characterized to bound driving environments for all failure modes. Applied environments, either test or analytical, must be representative of flight environments and have a load factor that satisfies design requirements. 3. Structural verification must include all failure modes. A comprehensive list of failure modes and the underlying failure mechanisms has been generated based on flight and test experience. Verification tests and / or analyses must address each failure mode. ET TPS Verification is accomplished by a combination of analysis, test, and similarity.
Statistics on wreath products, perfect matchings, and signed words

We introduce a natural extension of Adin, Brenti, and Roichman's major-index statistic nmaj on signed permutations (Adv. Appl. Math. 27 (2001) 210-224) to wreath products of a cyclic group with the symmetric group. We derive "insertion lemmas" which allow us to give simple bijective proofs that our extension has the same distribution as another statistic on wreath products introduced by Adin and Roichman (European J. Combin. 22 (2001) 431-446) called the flag major index. We also use our insertion lemmas to show that nmaj, the flag major index, and an inversion statistic have the same distribution on a subset of signed permutations in bijection with perfect matchings. We show that this inversion statistic has an interpretation in terms of q-counting rook placements on a shifted Ferrers board.Many results on permutation statistics extend to results on multiset permutations (words). We derive a number of analogous results for signed words, and also words with higher-order roots of unity attached to them.
Purification of a human urinary colony‐stimulating factor

Colony-stimulating factor (CSF), a protein required for the in vitro formation of colonies composed of granulocytes and/or macrophages, was isolated from the urine of anemic patients by using a seven-step procedure. The purified, homogeneous CSF had a specific activity of 1.9 × 108 U/absorbance unit at 280 nm (AU). This represents an overall purification of 25,330-fold and a total recovery of 3.8%. Upon iodination of the protein, the radioactivity migrated on sodium dodecyl sulfate (SDS) gel electrophoresis as a single peak with an apparent molecular weight of 46,000; reduction with mercaptoethanol caused dissociation to a single component of molecular weight 23,000. Only the dimer is active in stimulating colony formation. Urinary CSF stimulates formation of colonies comprising only macrophages in the mouse bone' marrow cell culture assay. A neutralizing antibody raised against mouse L-cell CSF did not neutralize the activity of the urinary CSF but did bind it. This may indicate that the relative positions of antibody binding sites and the active sites are different in these two glycoproteins.
A novel rearrangement forming 4,5,6,11-tetra-hydrobenzo[6,7]cycloocta[1,2-b]thiophen-6,11-imines

Abstract Exposure of the spirocyclic isoindolines 9 and 16 and the spirocyclic ether 23 to HBr gas in methylene chloride at 0°C leads to the formation of the bridged heterocycles 10 , 17 , and 24 respectively. These novel rearrangements probably occur via retro-Mannich fragmentation and subsequent intramolecular Mannich reaction on the thiophene ring.
Surface enhanced Raman scattering by surface plasmon enhancement of electromagnetic fields near spheroidal particles on a roughened metal surface

Abstract It is shown that surface plasmon resonances at prolate-spheroidally shaped irregularities on roughened silver, copper, and gold surfaces can greatly increase the Raman scattering cross sections of adsorbed molecules by increasing both the local. Held of the exciting radiation and the radiation-induced molecular dipole moment.
Algal productivity and nitrate assimilation in an effluent dominated concrete lined stream

This study examined algal productivity and nitrate assimilation in a 2.85 km reach of Cucamonga Creek, California, a concrete lined channel receiving treated municipal wastewater. Stream nitrate concentrations observed at two stations indicated nearly continuous loss throughout the diel study. Nitrate loss in the reach was approximately 11 mg/L/d or 1.0 g/m 2 /d as N, most of which occurred during daylight. The peak rate of nitrate loss (1.13 mg/l/hr) occurred just prior to an afternoon total CO 2 depletion. Gross primary productivity, as estimated by a model using the observed differences in dissolved oxygen between the two stations, was 228 mg/L/d, or 21 g/m 2 /d as O 2 . The observed diel variations in productivity, nitrate loss, pH, dissolved oxygen, and CO 2 indicate that nitrate loss was primarily due to algal assimilation. The observed levels of productivity and nitrate assimilation were exceptionally high on a mass per volume basis compared to studies on other streams; these rates occurred because of the shallow stream depth. This study suggests that concrete-lined channels can provide an important environmental service: lowering of nitrate concentrations similar to rates observed in biological treatment systems.
Diversity in Mating Behavior of Hermaphroditic and Male–Female Caenorhabditis Nematodes

In this study, we addressed why Caenorhabditis elegans males are inefficient at fertilizing their hermaphrodites. During copulation, hermaphrodites generally move away from males before they become impregnated. C. elegans hermaphrodites reproduce by internal self-fertilization, so that copulation with males is not required for species propagation. The hermaphroditic mode of reproduction could potentially relax selection for genes that optimize male mating behavior. We examined males from hermaphroditic and gonochoristic (male–female copulation) Caenorhabditis species to determine if they use different sensory and motor mechanisms to control their mating behavior. Instead, we found through laser ablation analysis and behavioral observations that hermaphroditic C. briggsae and gonochoristic C. remanei and Caenorhabditis species 4, PB2801 males produce a factor that immobilizes females during copulation. This factor also stimulates the vulval slit to widen, so that the male copulatory spicules can easily insert. C. elegans and C. briggsae hermaphrodites are not affected by this factor. We suggest that sensory and motor execution of mating behavior have not significantly changed among males of different Caenorhabditis species; however, during the evolution of internal self-fertilization, hermaphrodites have lost the ability to respond to the male soporific-inducing factor.
Migration to the United States and Mexican Rural Development: A Case Study

An analysis of the impact of migration to the United States on the sending community and on the labor market in the receiving country is presented based on a case study of Las Animas Mexico. "As the community becomes increasingly involved in migration tendencies can be identified regarding changing migration patterns class differentiation among villagers impact of migration on village economy and the changing role of Mexican workers in California labor markets. Results indicate the importance of social networks in determining the outcome of migration; while migration is individually rational it is a factor of stagnation for village economy and it helps reproduce segmented California labor markets." (EXCERPT)
Electrostatic scalar potential and electric field solution of an axisymmetric accelerator gap

Abstract A computationally efficient formulation of the solution for the electric potential and field due to an axisymmetric accelerator gap is derived. The potential solution is obtained from an accurate integration of the Green function integral solution of Laplace's equation. This result provides information about the focusing properties of a gap, and can be used to obtain forces needed in particle transport codes.