cssi/SciSciGPT-SciSciNet huggingface dataset:
Crystal structure of the 65-kilodalton amino-terminal fragment of DNA topoisomerase I from the gram-positive model organism Streptococcus mutans.

Abstract Herein we report the first structure of topoisomerase I determined from the gram-positive bacterium, S. mutans. Bacterial topoisomerase I is an ATP-independent type 1A topoisomerase that uses the inherent torsional strain within hyper-negatively supercoiled DNA as an energy source for its critical function of DNA relaxation. Interest in the enzyme has gained momentum as it has proven to be essential in various bacterial organisms. In order to aid in further biochemical characterization, the apo 65-kDa amino-terminal fragment of DNA topoisomerase I from the gram-positive model organism Streptococcus mutans was crystalized and a three-dimensional structure was determined to 2.06 A resolution via x-ray crystallography. The overall structure illustrates the four classic major domains that create the traditional topoisomerase I “lock” formation comprised of a sizable toroidal aperture atop what is considered to be a highly dynamic body. A catalytic tyrosine residue resides at the interface between two domains and is known to form a 5’ phosphotyrosine DNA-enzyme intermediate during transient single-stranded cleavage required for enzymatic relaxation of hyper negative DNA supercoils. Surrounding the catalytic tyrosine residue is the remainder of the highly conserved active site. Within 5 A from the catalytic center, only one dissimilar residue is observed between topoisomerase I from S. mutans and the gram-negative model organism E. coli. Immediately adjacent to the conserved active site, however, S. mutans topoisomerase I displays a somewhat unique nine residue loop extension not present in any bacterial topoisomerase I structures previously determined other than that of an extremophile.
JAK2V617F Promotes Atherosclerosis

Abstract Myeloproliferative disorder (MPD) patients are at high risk of atherothrombotic events including myocardial infarction and stroke. The somatic mutation (JAK2V617F) is commonly found in MPD patients and is associated with increased vascular risk. Moreover, the prevalence of JAK2V617F mutation is also significantly increased in non-MPD coronary artery disease (CAD) and peripheral artery disease (PAD) patients compared to the general population. Our goal was to investigate potential mechanisms of accelerated atherothrombosis using a JAK2V617F mouse model. Subletahlly irradiated Ldlr-/- mice were transplanted with bone marrow cells from wild type (WT) or Mx1-Cre/Jak2V617F (Jak2VF) mice and fed a high fat high cholesterol Western type diet (WTD). After 7 weeks of WTD Jak2VFmice had sustained neutrophilia, monocytosis and erythrocytosis; despite lower plasma cholesterol levels they showed ~1.6 fold larger atherosclerotic lesions in the aortic root (p=0.003) and accelerated carotid artery thrombosis (FeCl3 injury). After 12 weeks of WTD feeding, lesion area was only increased 1.3-fold compared to controls but showed features of plaque instability (increased necrotic core area). Early lesions (7 weeks) displayed significantly increased neutrophils (p=0.05, n=7) but not Mac 3+ macrophages. The increased neutrophil infiltration in Jak2VF mice correlated with atherosclerotic lesion size (p=0.001, r=0.78), suggesting a critical role of neutrophils in early atherogenesis. Advanced lesions (12 weeks) also showed significantly increased neutrophil (p=0.001) and macrophage (p=0.05) infiltration. No difference in CD3+ T cells or CD41+ platelet infiltration was observed at either time-point. In addition, five out of nine Jak2VF mice had prominent iron deposition (Prussian blue) and RBC marker Ter-119 staining in advanced atherosclerotic lesions (p In summary, the Jak2V617F mutation promotes early atherosclerotic lesion development and plaque instability in advanced lesions. Neutrophil infiltration appears to be an important contributor to both early lesion development and necrotic core formation. These studies also suggest a novel role for RBC infiltration, iron deposition and erythrophagocytosis in advanced lesional necrotic core formation in JAK2V617F mice. Disclosures Levine: Novartis: Consultancy; Qiagen: Membership on an entity's Board of Directors or advisory committees. Tall: Amgen: Consultancy; CSL Behring: Consultancy.
Metal-Organic Frameworks against Toxic Chemicals

Materials capable of the safe and efficient capture or degradation of toxic chemicals, including chemical warfare agents (CWAs) and toxic industrial chemicals (TICs), are critically important in the modern age due to continuous threats of these chemicals to human life, both directly and indirectly. Metal-organic frameworks (MOFs), atomically precise hybrid materials that are synthesized via the self-assembly of metal cations or clusters and organic linkers, offer a unique solid adsorbent design platform due to their great synthetic versatility. This review will focus on recent advancements in MOF-based adsorbent design for protection against chemical warfare agents (organophosphorus nerve agents, blistering agents, and their simulants) and toxic industrial chemicals such as H2S, NH3, SO2, CO, NO2, and NO.
Strategic Audit Materiality, Information Asymmetry, and Investment Efficiency

Regulators have proposed materiality standards in order to mitigate audit costs resulted from the Sarbanes-Oxley Act of 2002. We argue that materiality thresholds are a two-edged sword. Restrictive materiality thresholds increase the cost of misstatements, thereby reducing the cost of information asymmetry and increasing investment efficiency. However, investors may be negatively affected by litigation friction resulted from noisy audit evidence and inefficient legal systems. This economic trade-off creates the demand for materiality thresholds. We find that the optimal materiality thresholds are asymmetrical and contingent on firms’ reports. Investors impose restrictive materiality if firms’ reports are optimistic; otherwise, the discrepancy between audit evidence and firms’ reports may be ignored. We further identify the conditions under which the investor may benefit from auditors’ attestation services. Our analysis implies that a mandatory materiality threshold imposed by the Act may lead to investment inefficiency.
Great Lakes Creoles: A French-Indian Community on the Northern Borderlands, Prairie du Chien, 1750–1860

Introduction 1. 'The rightful owners of the soil': colonization and land 2. 'To intermeddle in political affairs': new institutions, elections, and lawmaking 3. 'Damned yankee court and jury': more new institutions, keeping order and peace 4. Public mothers: women, networks, and changing gender roles 5. 'A humble type of people': economic adaptations 6. Blanket claims and family clusters: autonomy, land, migration, and persistence Conclusion Epilogue.
Boundary Array Transducer and Beamforming for Low-Cost Real-time 3D Imaging

Recent studies suggest that ultrasound can be used for serial monitoring to guide therapeutic interventions at the point of care. A low-cost 3-D imaging may be well suited for this application due to greater accuracy and reproducibility over 2-D imaging. Previous work on arrays and systems for 3D imaging have focused on either 2D array transducers, hardware, or software alone. In this work, a systems-based “ground up” approach to develop real-time 3D (RT3D) ultrasound is investigated and compared to a full-sampled array. A 3 MHz, 64 × 64 rectangular boundary array was simulated in Field II and compared to a fully-sampled array. To improve depth of penetration, coded excitation is used. Due to the sparseness of the RBA, novel apodization techniques are applied to suppress sidelobes and clutter.
Commercial kefir products assessed for label accuracy of microbial composition and density

Abstract Kefirs are fermented beverages containing yeast and bacteria produced by the fermentation of water or milk with kefir grains. Because microorganism density may influence a product's health benefits, label accuracy regarding viable bacterial density and taxonomy of fermented foods is important. In this study, the microbiota of 5 commercial kefir products were measured quantitatively using standard plating techniques and characterized using high-resolution, long-read 16S rRNA gene amplicon sequencing. To enumerate viable lactic acid bacteria, 2 lots of each product were plated on de Man, Rogosa and Sharpe agar upon opening and following 14 d and incubated under anaerobic and aerobic conditions. Results revealed that 66% of products with a guaranteed count of colony-forming units per gram overstated microorganism density by at least 1 log, with only product E exceeding 1 × 109 cfu/g. Sequencing results demonstrated moderate product label accuracy in regard to taxonomy, yet several products contained bacterial species above the minimum detectable threshold (0.001% relative abundance) that were not included on the labels (e.g., Streptococcus salivarius, Lactobacillus paracasei). Our results demonstrate a moderate level of labeling accuracy for commercial kefir products intended for human consumption. Regulatory agencies and consumers must continue to scrutinize these products and demand a higher level of accuracy and quality.
Does Performing Endoscopy Sooner Have an Impact on Outcomes in Patients With Acute Nonvariceal Upper Gastrointestinal Hemorrhage? A Systematic Review.

Background Endoscopy is the cornerstone for the diagnosis and treatment of nonvariceal upper gastrointestinal bleeding. Regarding the management of nonvariceal bleeding, the administration of crystalloid solution and proton pump inhibitors before endoscopy is well established, but the optimal timing of endoscopy has been a matter of debate and a subject of many investigational studies. The need for urgent endoscopy arises to provide prompt redress to acute bleeding, decrease the length of stay, and lower mortality from ongoing bleeding. Objective This study aimed to determine if endoscopy performed within 24 hours of presentation improves outcomes in terms of mortality, hospital length of stay, and rebleeding in individuals presenting with nonvariceal upper gastrointestinal bleed with any risk. Methodology We performed a systematic review of two large databases (PubMed and Google Scholar) to incorporate all studies published after 2000. We included studies with nonvariceal upper gastrointestinal bleeding and excluded those reporting variceal gastrointestinal hemorrhage. Results We reviewed eight studies that qualified after meeting our inclusion and exclusion criteria. We divided these studies into three separate groups based on the timing of endoscopy. Only two studies found a difference in mortality that was statistically significant in patients who underwent endoscopy within 24 hours of presentation. One study showed lower mortality in a patient who underwent urgent endoscopy, but it did not reach statistical significance. Other studies did not show any statistical difference in mortality, hospital length of stay, and rebleeding rates. The studies showed conflicting evidence on the amount of blood transfusion, though urgent endoscopy was found to be difficult in few studies due to blood obscuring the lesion. Conclusions While data suggest that there is a potential benefit in performing endoscopy sooner, there is no concrete evidence to point to a particular time range. Before performing endoscopy, the American Society for Gastrointestinal Endoscopy (2012) recommends adequate resuscitation with crystalloid solutions, blood transfusions, and antisecretory and prokinetic agent therapy. More investigational studies are needed to formulate a time-sensitive flow sheet to approach endoscopy in patients with nonvariceal upper gastrointestinal bleeding. A strict criterion is also needed to delineate patients into low-risk and high-risk groups. Doing so would provide a systematic approach to help with mortality, rebleeding, and healthcare resource utilization.
THE CORONAVIRUS RECESSION IN THE U.S.: IS THERE A LONG-RUN FOOTPRINT?

The U.S. coronavirus recession began in late February of 2020 and was over in two months. The rapid recovery was due to the Coronavirus Aid, Relief, and Economic Stability Act (CARES Act), a large ...
Oxidation Studies for 6H-SiC

Polytype 6H silicon carbide samples having polar faces terminated with either carbon (000\(\bar 1\)) or silicon (0001) have been oxidized at 810°C for varying times using a microwave plasma source. Silicon dioxide layer thicknesses have been determined using Rutherford backscattering techniques, and the oxidized samples were further characterized using capacitance-voltage techniques and the methods of Raman spectroscopy. Results indicate that oxide layers of comparable quality to those produced using standard thermal oxidation methods can be obtained in less time at lower temperature.
Does market integration buffer risk, erode traditional sharing practices and increase inequality? A test among Bolivian forager-farmers

Sharing and exchange are common practices for minimizing food insecurity in rural populations. The advent of markets and monetization in egalitarian indigenous populations presents an alternative means of managing risk, with the potential impact of eroding traditional networks. We test whether market involvement buffers several types of risk and reduces traditional sharing behavior among Tsimane Amerindians of the Bolivian Amazon. Results vary based on type of market integration and scale of analysis (household vs. village), consistent with the notion that local culture and ecology shape risk management strategies. Greater wealth and income were unassociated with the reliance on others for food, or on reciprocity, but wealth was associated with a greater proportion of food given to others (i.e., giving intensity) and a greater number of sharing partners (i.e., sharing breadth). Across villages, greater mean income was negatively associated with reciprocity, but economic inequality was positively associated with giving intensity and sharing breadth. Incipient market integration does not necessarily replace traditional buffering strategies but instead can often enhance social capital.
Construction of a Semiconductor–Biological Interface for Solar Energy Conversion: p-Doped Silicon/Photosystem I/Zinc Oxide

The interface between photoactive biological materials with two distinct semiconducting electrodes is challenging both to develop and analyze. Building off of our previous work using films of photosystem I (PSI) on p-doped silicon, we have deposited a crystalline zinc oxide (ZnO) anode using confined-plume chemical deposition (CPCD). We demonstrate the ability of CPCD to deposit crystalline ZnO without damage to the PSI biomaterial. Using electrochemical techniques, we were able to probe this complex semiconductor–biological interface. Finally, as a proof of concept, a solid-state photovoltaic device consisting of p-doped silicon, PSI, ZnO, and ITO was constructed and evaluated.
NEW MEDIA AND NATURAL DISASTERS: Blogs and the 2004 Indian Ocean tsunami

This article examines the role of blogs during the aftermath of the 2004 Indian Ocean tsunami. Using a blog created by South Asian journalists as a case study, the article argues that new media has the potential to be a democratizing agent in lesser developed countries. The article argues that some tsunami-related blogs give regional, subaltern journalists a medium to transcend exploitative accounts of the tsunami's aftermath. The article is also able to use tsunami-related blogs to help highlight questions surrounding new media and disaster reporting in lesser developed countries in general, including discussions of the digital divide.
Access to another mind: Naturalistic theories require naturalistic data

If there is to be a natural theory of consciousness that would satisfy both philosophers and scientists, it must be based on naturalistic data and minimal clutter accumulated from semantic arguments. Carruthers offers a 'natural' theory of consciousness that is rather myopic. To explore the evolutionary basis of consciousness, a natural theory should include comparative psychological and neurological data that encompass nonlinguistic measures. Such an approach could provide a clearer picture of the adaptive function, mechanisms, and origins of consciousness.
Micromachined intraluminal devices for active and passive electromagnetic measurements of flow

This paper outlines architectures for implantable (active and passive) sub-systems intended for monitoring of intraluminal blood flow by electromagnetic transduction, and presents the fabrication and test results of select components within these sub-systems. Central to both schemes is a ring-shaped intraluminal stainless steel cuff with two electrodes. In the presence of a magnetic field, it produces a voltage proportional to the flow velocity. It is fabricated by micro-electro-discharge machining and deployed by an angioplasty balloon. Cuffs deployed within 3-mm i.d. silicone tubes demonstrate linear and symmetric responses of 3.1-4.3 /spl mu/V per cm/sec over 180 cm/sec with magnetic fields of about 0.25 T. In the passive monitoring scheme, voltage from the cuff modulates a varactor that is also connected to an antenna stent (stentenna). This approach is explored using a hybrid diode for the varactor and a stentenna deployed within a mock artery. Preliminary tests in saline indicate that an external transmitting coil will experience shifts in phase spectrum of 2.0-3.3 KHz/mV of output from the cuff.
Antiserum Inactivation of Electrophoretically Purified M13 Diploid Virions: Model for the F-Specific Filamentous Bacteriophages

Antiserum inactivation experiments were carried out on electrophoretically purified diploid virions from a cross between two complementing amber mutants of phage M13. The total (homozygous plus heterozygous) diploid population, assayed on a permissive host where only one genome is needed for plaque formation, was inactivated at the same rate as haploids. Heterozygous diploids, assayed on a nonpermissive host, where both genomes are needed for plaque formation, were twice as sensitive as haploids and the total diploid population. These results have led us to propose a model for serum inactivation of the F-specific filamentous phages. According to this model, phage-neutralizing antibodies attach anywhere along the length of the phage and allow the phage to penetrate only up to the first bound antibody molecule.
Galectin-3 Functions as an Adhesion Molecule to Support Eosinophil Rolling and Adhesion under Conditions of Flow

Allergic inflammation involves the mobilization and trafficking of eosinophils to sites of inflammation. Galectin-3 (Gal-3) has been shown to play a critical role in eosinophil recruitment and airway allergic inflammation in vivo. The role played by Gal-3 in human eosinophil trafficking was investigated. Eosinophils from allergic donors expressed elevated levels of Gal-3 and demonstrated significantly increased rolling and firm adhesion on immobilized VCAM-1 and, more surprisingly, on Gal-3 under conditions of flow. Inhibition studies with specific mAbs as well as lactose demonstrated that: 1) eosinophil-expressed Gal-3 mediates rolling and adhesion on VCAM-1; 2) α 4 integrin mediates eosinophil rolling on immobilized Gal-3; and 3) eosinophil-expressed Gal-3 interacts with immobilized Gal-3 through the carbohydrate recognition domain of Gal-3 during eosinophil trafficking. These findings were further confirmed using inflamed endothelial cells. Interestingly, Gal-3 was found to bind to α 4 integrin by ELISA, and the two molecules exhibited colocalized expression on the cell surface of eosinophils from allergic donors. These findings suggest that Gal-3 functions as a cell surface adhesion molecule to support eosinophil rolling and adhesion under conditions of flow.
The C 3 Theorem and a D 2 Algorithm for Large Scale Stochastic Mixed-Integer Programming: Set Convexification

This paper considers the two-stage stochastic integer programming problem, with an emphasis on instances in which integer variables appear in the second stage. Drawing heavily on the theory of disjunctive programming, we characterize convexifications of the second stage problem and develop a decomposition-based algorithm for the solution of such problems. In particular, we verify that problems with fixed recourse are characterized by scenario-dependent second stage convexifications that have a great deal in common. We refer to this characterization as the C3 (Common Cut Coefficients) Theorem. Based on the C3 Theorem, we develop a decomposition algorithm which we refer to as Disjunctive Decomposition (D2). In this new class of algorithms, we work with master and subproblems that result from convexifications of two coupled disjunctive programs. We show that when the second stage consists of 0-1 MILP problems, we can obtain accurate second stage objective function estimates after finitely many steps. This result implies the convergence of the D2 algorithm.
Numerical Analysis of the Impact of Elliptical Fields on Magnetization Losses

AC losses need to be accurately estimated in order to develop more accurate thermal models for fully superconducting machines. In the framework of the development of a high-fidelity sizing tool for superconducting rotating machine for NASA, simulations showed that the classical models for ac losses, taking into account a purely alternating field, would not provide accurate estimations for the magnetization losses. Indeed, superconducting stators usually exhibit a large electrical loading and therefore are subjected to both alternating and rotating fields. As preliminary analysis, a numerical 2-D model is developed to calculate the magnetization losses generated by an elliptical magnetic field in a filament or round mono-core wire. The simulations are based on the H-formulation and executed using a commercial finite element analysis solver. The elliptical magnetic field applied to the superconducting wire is produced by a linear combination of both alternating and rotating fields. The load angle of the rotating machine, creating an angular shift between the alternating and rotating fields, has an impact on the losses and is taken into account. At this point of the study, no transport current is considered. We focus on the ratio between the effective losses and the losses created by a purely alternating field, which are considered known. The investigation leads to a fit formula of the ratio, which has been implemented in a high-fidelity superconducting machine model.
When to bid for government contracts

Abstract This article looks at the issue as to whether or not to participate in the competition. The model formulated what calculations to make and how to present the results for a two-stage (R&D and production) bid decision problem.
Hindered and Enhanced Coalescence of Drops in Stokes Flows

We analyze axisymmetric near-contact motion of two drops under the action of an external force or imposed flow. It is shown that hydrodynamic stresses in the near-contact region that are associated with the outer (drop-scale) flow can qualitatively affect the drainage of the thin fluid film separating the drops. If this far-field stress acts radially inward, film drainage is arrested at long times; exponential film drainage occurs if this stress acts outward. An asymptotic analysis of the stationary long-time film profile is presented for small-deformation conditions, and the critical strength of van der Waals attraction for film rupture is calculated. The effect of an insoluble surfactant is also considered. Hindered and enhanced drop coalescence are not predicted by the current theories, because the influence of the outer flow on film drainage is ignored.
Urey-Bradley potential constants in dinitrogen trioxide

Abstract Urey-Bradley force constants from nitrogen dioxide, nitrite ion, nitrosyl halides, nitryl halides and dinitrogen tetroxide, all reported earlier, have been used to calculate the vibrational frequencies in dinitrogen trioxide. Since the structure of the trioxide is not known, several possible structures were considered and the effect of these on the calculated frequencies was determined. On the basis of these calculations, the most reasonable structure of the molecule appears to be the planar form with the N-N bond distance of about 2.08 A or greater and the N-N-O (nitroso) angle less than about 110°.
Phase Equilibria in the System CaO—MgO

The liquidus, solidus, and subsolidus of the system CaO–MgO have been redetermined. X-ray diffraction and optical techniques show that the maximum solid solution of MgO in the CaO lattice is approximately 17 wt% at 2370°C and the maximum solid solution of CaO in the MgO lattice is approximately 7.8 wt% at 2370°C. The extent of solid solution in each case is substantially greater than previously reported. Magnesium oxide and calcium oxide solid solutions exist at temperatures above 1600°C. The liquidus values closely agree with those previously reported by Rankin and Merwin.
Quasi-developed turbulent pipe flow with heat transfer

Downstream heat transfer and wall friction predictions for quasi-developed strongly heated turbulent pipe flow, using mixing length model
Assay of histamine by nano-liquid chromatography/tandem mass spectrometry with a packed nanoelectrospray emitter.

A nano-liquid chromatographic /tandem mass spectrometric (nanoHPLC/MS/MS) method has been developed for the sensitive determination of histamine, a vital neurotransmitter. The method involved pre-column derivatization of histamine with 7-fluoro-4-nitrobenzoxadiazole (NBD-F), thus increasing the hydrophobicity of the analyte and allowing it to be retained and stacked on a nanoelectrospay emitter packed with C18 reversed-phase particles. Sodium 1-heptanesulfonate, added as an ion-pairing reagent in the mobile phase for sample loading, was found to facilitate greatly the analyte retention. The packed nanoelectrospray emitter was easily prepared using fused-silica capillary of 75 μm i.d., and included creating an electrospray emitter tip and then slurry-packing a 5 cm long column with 5 μm silica-based particles. After sample loading, the mobile phase was changed for separation and a characteristic precursor-to-product ion transition, m/z 275 258, was used for the quantification. A linear calibration curve in the range from 1.0–100 ng/mL histamine with an r2 value of 0.9995 was obtained. The detection limit was estimated to be 0.1 ng/mL histamine in water. In a preliminary validation, the method was applied to determine histamine in alcoholic beverages and rat brain tissues. Copyright © 2004 John Wiley & Sons, Ltd.
Extensive peroxynitrite activity during progressive stages of central nervous system inflammation

Nitric oxide (NO) production has been associated with disease activity in multiple sclerosis and experimental autoimmune encephalomyelitis (EAE). This free radical can be transformed by superoxide to peroxynitrite, an extremely toxic oxidant which causes lipid peroxidation. In addition, peroxynitrite nitrates tyrosine residues, resulting in nitrotyrosine, which can be identified immunohistochemically. The results of this study indicate that peroxynitrite is formed very early during EAE development, correlating with clinical disease activity. Nitrotyrosine-positive cells display a widespread distribution in brain and spinal cord during severe disease and are associated with both perivascular infiltrates and parenchymal sites. Double-staining procedures demonstrated that a subpopulation of CD11b-positive cells (macrophages/microglia) reacted with nitrotyrosine antibodies. Immunostaining for inducible NO synthase demonstrated a similar distribution as nitrotyrosine staining. These experiments indicate that peroxynitrite is formed during progressive stages of disease activity.
No demonstration that g is not unitary, but there's more to the story :comment on Kranzler and Jensen

Because they employed a statistical procedure that was inappropriate for the purpose, Kranzler and Jensen (1991) have not demonstrated that a factor of general intelligence, g, depends on a number of independent processes. It is more parsimonious to interpret their results in terms of a g that is unitary. A factorial reanalysis of their data, including some that they did not present (cross-correlations between psychometric variables and variables from elementary cognitive tasks, or ECTs), shows that many ECT variables, especially those reflecting decision time rather than movement time, have substantial loadings on a second-order general factor. This factor is orthogonal to a second-order factor representing general speed of movement from a “home button” to the response button in ECTs. Possible implications for interpreting g in terms of information-processing efficiency are discussed.
Placental villous glucose metabolism and hormone release respond to varying oxygen tensions.

Objective The effects of varying oxygen tensions on tissue metabolic behavior are not well understood, yet many intracellular pathways are influenced by them. In the placenta, optimal in vivo oxygen tension at the villous level is unknown. The purpose of this study was to determine effects of varying oxygen tensions on glucose metabolism and hormone release from perifused placental villous explants. Methods Placentas from term normal pregnancies (n = 8) were individually minced into villous fragments, placed into three parallel chambers for each placenta, and continuously perifused for 6 hours with nonrecirculating medium aerated with either 0%, 20%, or 95% oxygen yielding mean oxygen tensions of 76 mmHg, 167 mmHg, and 543 mmHg respectively. Outflow medium was removed at regular intervals and compared to the inflow medium to determine oxygen and glucose consumption as well as lactate, lactate dehydrogenase, hCG, estradiol, and progesterone release. Results Oxygen consumption was directly proportional to oxygen tension. Glucose consumption was lowest at low oxygen tension, while both lactate and LDH release were lowest at high oxygen tension. Both hCG and progesterone release rates were lowest at high oxygen tensions. Estradiol release demonstrated a trend similar to that of the other hormones although there was no statistically significant difference among the three different levels of oxygen tension. Conclusion Varying oxygen tensions affect placental villous glucose metabolism and hormone release. Under lower oxygen tensions, glucose is metabolized through glycolysis rather than through oxidative phosphorylation and is associated with higher lactate release. Exposure to higher oxygen tensions results in reduced hCG and progesterone release. Higher oxygen tensions may be associated with tissue toxicity.
A hypothesis for delayed dynamic earthquake triggering

[1] It's uncertain whether more near-field earthquakes are triggered by static or dynamic stress changes. This ratio matters because static earthquake interactions are increasingly incorporated into probabilistic forecasts. Recent studies were unable to demonstrate all predictions from the static-stress-change hypothesis, particularly seismicity rate reductions. However, current dynamic stress change hypotheses do not explain delayed earthquake triggering and Omori's law. Here I show numerically that if seismic waves can alter some frictional contacts in neighboring fault zones, then dynamic triggering might cause delayed triggering and an Omori-law response. The hypothesis depends on faults following a rate/state friction law, and on seismic waves changing the mean critical slip distance (Dc) at nucleation zones.
The subculture of violence and ethnicity

Abstract Using data from the General Social Surveys, this article examines the subculture of violence thesis as it relates to three ethnic groups—blacks, Hispanics, and American Indians. The data suggest that blacks and American Indians have had more violence experiences (hitting and firearms) than have the general population. Contrary to what would be predicted from the thesis, the data indicate that blacks and Hispanics had lower tolerance of violence than the general population. Only American Indians, on all factors considered, appeared to support the thesis. Even this support, however, took on less significance when regression results were examined. Demographic and residential variables explained more of the variance in violence tolerance and experiences with violence than did ethnic background. These findings suggest that the influence of ethnicity on the subculture of violence is minor and indirect.
Characteristics of midbrain respiratory neurons in sleep and wakefulness in the cat.

Abstract Midbrain neurons were recorded in sleep and wakefulness in chronic cats. In the first phase of this study, we attempted to detect respiratory neurons by observing neuronal activity on an oscilloscope and listening to it after audioamplification. We studied 780 neurons in this non-quantitative way and failed to detect any respiratory activity. In the second phase, 203 neurons were analyzed statistically: 15% of these had activity patterns significantly related to the respiratory cycle. In the third and final phase, we studied the details of the activity of midbrain respiratory neurons. Sixteen of 281 single neurons had discharge patterns significantly related to the respiratory cycle, but only 3 of the 16 were related to breathing with a consistency that essentially excluded the possibility of a false positive error. All 3 of these cells were only intermittently respiratory, and the intermittency varied from cell to cell and tended to depend upon the state of consciousness. These results differ substantially from reports that more than 30% of midbrain and diencephalic cells are respiratory neurons. The differences may be explained by the previous authors' use of a statistic, the respiratory modulation index, that, as shown here and in a previous simulation study, produces a large number of false positive errors.
The phyllochron of Prunus persica shoots is relatively constant under controlled growth conditions but seasonally increases in the field in ways unrelated to patterns of temperature or radiation

Abstract Growth and development of plants are characterized by the addition of repeated units called phytomers that consist of a node, internode, leaf and axillary bud. The time elapsed between the addition of phytomers can be represented by the appearance of leaves at each node, or the leaf appearance rate (LAR). The inverse of LAR is the phyllochron, the chronological time or thermal time elapsed between the appearance of successive leaves along a stem. Plant genotype interactions with environment are responsible for the timing of the phyllochron. Temperature is important for the regulation of many plant processes. To what extent temperature regulates the phyllochron of fruit trees is not clear. Furthermore, the correct thermal time scale to employ for determining the phyllochron has yet to be determined. The objective of this study was to develop a growing degree hour (GDH) thermal time scale model for measuring the phyllochron of Prunus persica and to determine if temperature is the primary factor that influences the phyllochron under field conditions. A temperature-controlled growth chamber study was conducted to determine the appropriate temperatures to use in a GDH-based phyllochron model. We developed a model that is linear on both sides of a plateau-shaped optimum. The base temperature was 4 °C, the critical or maximum temperature was 40 °C and the optimal temperature range spanned 18–32 °C. This GDH model was then used to model the phyllochron of proleptic peach shoots of mature grown trees in the field for two years. Even though the GDH model accounted for much of the daily fluctuations in the phyllochron, the phyllochron generally increased as the season progressed in a manner apparently unrelated to seasonal temperature or daily radiation patterns.
A mixed-integer nonlinear programming formulation for the synthesis of heat-integrated distillation sequences

Abstract Sequences of distillation columns are widely employed in chemical plants as the main system for the separation of various multicomponent mixtures into their components. Considerable savings in plant operating costs can often be obtained by adjusting the operating pressures of the columns in a separation sequence so as to allow for heat transfer between the condenser of one column and the reboiler of another. Because of the importance of distillation sequences in the operation of the entire chemical process and the large investment and operating costs represented by them, the synthesis of optimal heat-integrated distillation sequences becomes an important synthesis problem. In this paper, a systematic framework is presented for the synthesis problem of heat-integrated distillation sequences with the column pressures treated as continuous variables for a single multi-component feed of fixed composition. This framework consists of the mathematical formulation of the distillation sequence superstructure as a mixed-integer nonlinear programming MINLP problem. The mathematical formulation features as an objective function, the minimum total annual cost comprised of investment costs for the distillation columns and heat exchangers plus the operating costs based on utility consumption. The heat integration options are incorporated in the proposed formulation through the assignment of integer variables representing the potential condenser-reboiler matches. Solution of this mathematical formulation, which can be obtained automatically using the computer programming procedure APROS provides the optimal distillation sequence and heat integration matches as well as the operating pressures required for each column. The effectiveness of this systematic framework is illustrated with three example problems.
Influence of BioChrome on the response of metabolic hormones in PEMS-infected poults

Poult enteritis and mortality syndrome (PEMS), a disease that affects turkeys between 7 and 28 d of age, causes a severe inflammation of the intestinal tract and is characterized in poults by severe diarrhea, high morbidity, mortality, and stunting. The PEMS-associated mortality and growth depression is related to malabsorption and decreased metabolic activity caused, in part, by a possible insulin deficiency or insensitivity. Insulin receptors are stimulated by the glucose tolerance factor (GTF) that incorporates Cr. Body Cr deficiency can be exacerbated by dietary deficiency and by increased excretion due to stress associated with a diarrheal disease such as PEMS. BioChrome (BC) contains natural, preformed GTF, the bioactive form of Cr. Experiments were conducted in which BC was blended into poult starter feed at 400 ppb during the first 21 d posthatch. Body weights were determined at 1, 7, 14, and 21 d of age, and weekly feed conversions were calculated for each treatment group (control, BC, PEMS, and BC+PEMS). At 6 d post-hatch, each PEMS-designated poult was given a 0.1-mL oral gavage of a 10% suspension of feces from PEMS-infected poults. Blood samples were taken via cardiac puncture from four birds per treatment group at 7, 10, 14, 17, and 21 d of age. Radioimmunoassays were conducted for plasma insulin, glucagon, thyroxine (T4), and triiodothyronine (T3). Plasma insulin levels were depressed in PEMS-infected poults from Days 10 through 17, but plasma glucagon levels in the PEMS-infected poults were significantly elevated at 14 and 17 d, after which they returned to control levels in both of the PEMS-infected groups. The T3 and T4 levels were depressed through Day 21 in PEMS-infected poults, but with BC treatment these blood hormone levels rebounded by Day 21. Body weights of PEMS-infected poults were increased significantly by the BC treatment but not to the level of noninfected controls.
Structure of Nerve Growth Factor Complexed with the Shared Neurotrophin Receptor p75

Neurotrophins are secreted growth factors critical for the development and maintenance of the vertebrate nervous system. Neurotrophins activate two types of cell surface receptors, the Trk receptor tyrosine kinases and the shared p75 neurotrophin receptor. We have determined the 2.4 A crystal structure of the prototypic neurotrophin, nerve growth factor (NGF), complexed with the extracellular domain of p75. Surprisingly, the complex is composed of an NGF homodimer asymmetrically bound to a single p75. p75 binds along the homodimeric interface of NGF, which disables NGF's symmetry-related second p75 binding site through an allosteric conformational change. Thus, neurotrophin signaling through p75 may occur by disassembly of p75 dimers and assembly of asymmetric 2:1 neurotrophin/p75 complexes, which could potentially engage a Trk receptor to form a trimolecular signaling complex.
Myospherulosis of the oral hard and soft tissues

Myospherulosis is a unique, inflammatory, granulomatous lesion, which results from the action of lipid substances on extravasated erythrocytes. Petrolatum-based antibiotic ointments are the most frequent etiologic agents of iatrogenically acquired lesions. Six intraoral cases of myospherulosis are presented, including the first reported case in oral soft tissues. The literature of reported cases is summarized and the epidemiology, histopathology, and ultrastructure of the lesions are discussed. Predisposing events and recommendations for future use of petrolatum-based antibiotic ointments are presented.
Reinforcement as positive or negative meaning-extension: An empirical demonstration

According to logical learning theory, a reinforcement involves the extension of meanings predicated by subjects who are asked to perform in a learning task. Based on this theoretical position, it is predicted that subjects who are administered a reinforcement following their successful anticipation of the second member of a paired-associates unit will acquire their liked trigrams more readily than their disliked trigrams (mixed lists). Conversely, it is predicted that subjects who are reinforced following their incorrect anticipations of the second paired-associates member will acquire their disliked trigrams more readily than their liked. College students (divided equally by sex) were exposed to one of three reinforcement conditions: positive reinforcement, negative reinforcement, and no reinforcement (control). Trigrams reliably rated for likability by each subject were used as learnable materials. Although the control condition did not perform as expected, the remaining experimental conditions support the hypotheses.
UTILIZATION IN THE POLICY CYCLE: DIRECTIONS FOR RESEARCH*

The study of policy utilization has been unnecessarily confined to one policy stage and to one group of policymakers-high ranking civil servants. This article suggests to broaden research concerns by including the various stages of the policy cycle and the various policymakers. Utilization plays different functions in different stages and the incentives of policymakers in each stage are guided by self-interest and political-bureaucratic efficacy.
A micro, econometric investigation of choice of technology

A microstudy of the determinants of technological choice utilizing sample observations at the man-machine level from operating plants in Korea is presented. The study focuses on the choice between imported and locally made looms for cotton textile weaving in South Korea. During the late 1960s and early 1970s, indigenous looms sold for less than one-third the price of imported looms, yet the latter were purchased in large numbers. Export incentives in combination with cross subsidization between the domestic and export markets would appear to have elicited a larger volume of production of superior fabric varieties than would otherwise have been observed. In turn, the choice by producers of the imported automatic technology is generally associated with the production and export of these varieties. Producers' choices seem to be consistent with net worth maximizing behavior. Particularly important are the policies of credit access on preferential terms and exemption from tariffs coupled with an overvalued exchange rate. Policies encouraging the use of imported technology simultaneously discriminate against domestic textile machinery manufacturers, thus inappropriately retarding the development of the domestic engineering industry. 13 references.
Trends in Consumer Product Warnings Found in Voluntary Standards

Consumer products available today in the United States often have safety information on and accompanying them. This practice is far more common now than earlier in the 20th century. In this paper, the evolution of the use of warnings with consumer products is examined as they appeared in voluntary standards provided by one national standard making body, the American Society for Testing and Materials (ASTM). ASTM had been developing consensus voluntary standards since 1898, but it was not until the 1970s that it first focused on consumer products. Over the next three decades there were increases in the number and type of consumer products included. Further, for any given product, the amount of safety information frequently increased with subsequent revisions of a standard. These trends in warnings generally parallel the patterns observed with federally mandated warnings for consumer products.
Serum/glucocorticoid-inducible kinase can phosphorylate the cyclic AMP response element binding protein, CREB

To maintain homeostasis, cells often respond to stressful extra-cellular stimuli by new gene expression. Serum/glucocorticoid-induced kinase (SGK) is an immediate early gene whose expression is induced by a variety of extra-cellular stimuli. Here, we examine the possibility that SGK can directly phosphorylate the transcription factor cyclic AMP response element binding protein (CREB). In a cell-free context, SGK physically associates with CREB and SGK phosphorylates it on serine 133. Phospho-serine 133 is essential for stimulating the transcriptional activity of CREB. Further, we show that in a variety of cellular contexts, SGK phosphorylates CREB. Activation of receptor tyrosine kinase pathways or the phosphoinositide-dependent kinase 1 (PDK1) lead to SGK-dependent CREB phosphorylation. Hormonal stimulation of epithelial cells leads to the induction of endogenous SGK and CREB phosphorylation. A dominant-negative form of SGK blocks dexamethasone-induced CREB phosphorylation. Our studies indicate that stimulation of SGK can lead to CREB phosphorylation, suggesting that CREB-dependent gene transcription is an important link between stressful extra-cellular signals and cellular responses.
Love and Destruction in the Decameron: Cimone and Calandrino

This study explores the concepts of imagination, love and reason as portrayed in the stories of two characters in Giovanni Boccaccio's Decameron. Through Cimone and Calandrino, the author shows how Boccaccio intertwines imagination and the passion of love, manipulating their fragile relationship with rational thought. A primary purpose of the novella of Cimone is to point out the weaknesses that underlie notions of idealized, stilnovist love; and the fourth tale of Calandrino is its humorous counterpart. Of special interest to this study is the fact that Boccaccio displays the concept of love with an emphasis not only on its failure to bring one to wisdom, but on its potential for danger. The essay also argues that while Boccaccio uses these tales to demonstrate the destructive force of erotic love, through them he also portrays the complicated ambiguity of the imagination.