cssi/SciSciGPT-SciSciNet huggingface dataset:
Finite element modeling of creep deformation in dendritic alloys

Abstract Finite element modeling is used to simulate the secondary creep rate of alloys with an inhomogeneous distribution of nano-precipitates, located within colonies of long, parallel dendrites, due to elemental segregation during directional solidification. Three-dimensional, periodic unit cells are created to approximate the aligned dendritic microstructure, with cylindrical dendrites (with high creep resistance due to nanoprecipitates) embedded within a precipitate-free matrix (with low creep resistance). Using creep power-laws for the precipitate-free matrix and the precipitation-strengthened dendrites, the creep rate of a dendritic aluminum alloy is computed for various dendrite geometry and volume fraction. When stress is applied parallel to the dendrite long axis, calculated creep rates are in reasonable agreement with creep measurements, at 300 °C, of a dendritic Al-0.07Sc-0.05Zr (at.%) alloy consisting of a pure Al matrix containing 50–60 vol% dendrites strengthened with L12-Al3(Sc,Zr) nanoprecipitates. Calculations for cases where aligned, cylindrical dendrites are ridged (emulating dendritic stubs) or bridged (emulating secondary arms) predict that these dendritic geometries, at constant volume fraction and parallel loading, strengthen less efficiently the matrix as compared to uniform cylindrical dendrites, reflecting a less effective load transfer between the two phases. When stress is applied perpendicular to the dendrites, the creep response becomes dominated by the matrix which shows higher stresses than under parallel loading, leading to much higher alloy creep rates. Alloys with bridged dendrites show the lowest perpendicular strain rate due to the alignment of the secondary arms (bridges) with the applied load, increasing load transfer to the precipitation-strengthened dendrites.
Comparative Determination of 2-Carbomethoxy-3-Alkyloxy- and Heteroaroyloxy-Substituted Tropanes in Illicit South American Cocaine Using Capillary Gas Chromatography-Single Ion Monitoring

Methodology is presented for the isolation and comparative determination of 16 alkyloyl and 2 heteroaroyl ecgonine methyl esters in illicit cocaine samples. These trace-level alkaloids, five of which are reported for the first time, were partially isolated from cocaine using alumina column chromatography and recrystallization and determined using capillary gas chromatography-mass spectrometry using selected ion monitoring. Acetoxy-, propionoyl-, isobutyroyl-, butyroyl-, 2-methylbutyroyl-, isovaleroyl-, valeroyl-, senecioyl-, trans-4-hexenoyl-, tigloyl-, hexanoyl-, 3′-furanoyl-, trans-2-hexenoyl-, 2′-furanoyl-, trans-3-heptenoyl-, cis-, trans-; trans-, cis-; and trans-, trans-2,4-hexadienoyl- ecgonine methyl esters were detected at levels less than 1 × 10−5 % (w/w relative to cocaine).
Abstract 125: Designated Stroke Center Status and Hospital Characteristics as Predictors of In-Hospital Mortality Among Hemorrhagic Stroke Patients in New York, 2008-2012

Background: While designated stroke centers (DSC) improve quality of care and outcomes for ischemic stroke patients, less is known regarding the benefits of DSCs for patients with intracerebral (ICH) and subarachnoid hemorrhage (SAH). Hypothesis: Compared to non-DSCs, hospitals with DSC status will have lower in-hospital mortality for hemorrhagic stroke patients independently of other hospital-level characteristics, including hospital size, urban location, and teaching status. Methods: We evaluated ICH (ICD-9 431) and SAH (ICD-9 430) hospitalizations that were recorded in the 2008-2012 New York State Department of Health’s Statewide Planning and Research Cooperative System (SPARCS) inpatient sample database. The relationship between DSC status and in-hospital mortality was evaluated using generalized estimating equation logistic regression to calculate OR’s and 95% confidence intervals; analyses were adjusted for clustering of patients within facilities, other hospital characteristics, and individual level characteristics. In secondary analyses we explored if other hospital characteristics were associated with in-hospital mortality. Results: Of 6501 ICH and 3440 SAH patients, in-hospital mortality was higher among those with ICH compared to SAH (23.7% vs. 18.5%). Unadjusted analyses revealed DSC was related with reduced mortality for both ICH (OR: 0.7; 0.6-0.8) and SAH patients (OR: 0.4; 0.3-0.7). DSC remained a significant predictor of in-hospital mortality for SAH patients (OR: 0.6; 0.4-0.9) but not for ICH patients (OR: 0.9; 0.6-1.2) after adjusting for patient demographic characteristics, comorbidities, hospital size, teaching status and location. Conclusions: Admission to a DSC was independently associated with reduced in-hospital mortality for SAH patients but not for those suffering from ICH. Other patient and hospital characteristics may explain the apparent benefit of PSC status on outcomes after ICH. Addressing gaps in stroke care through assessment of hospital-level factors indicates a potential target for quality of care improvement.
Two-Stage DEA: An Application to Major League Baseball

We show how to use DEA to model DMUs that produce in two stages, with output from the first stage becoming input to the second stage. Our model allows for any orientation or scale assumption. We apply the model to Major League Baseball, demonstrating its advantages over a standard DEA model. Our model detects inefficiencies that standard DEA models miss, and it can allow for resource consumption that the standard DEA model counts towards inefficiency. Additionally, our model distinguishes inefficiency in the first stage from that in the second stage, allowing managers to target inefficient stages of the production process.
Co-Operation and Timing

If players cannot perfectly synchronize their actions in a coordination game, an efficient outcome will never be achieved.
Renal Replacement Therapy

Acute renal failure (ARF) is a commonly anticipated diagnosis in critically ill patients in the intensive care unit (ICU). Its actual frequency varies from less than 10% to approximately 25% in different series including different patient demographics and definitions of ARF.1, 2, 3, 4, 5 The elevations in serum creatinine and urea nitrogen concentrations observed in a majority of these patients (more than 90%) are caused by renal hypoperfusion and related parenchymal dysfunction, the latter referred to as acute tubular necrosis (ATN)3,6 (Tables 33.1, 33.2). Between one-third and one-half of the observed ATN occurs during infection/sepsis, with the rest related to medical-surgical conditions, including hypotension and toxin exposure.3,6 ARF is typically accompanied by a number of comorbidities [i.e., respiratory failure (67%), heart failure (48%), and liver failure (31%)].7 In many series, more than one-half of the patients who develop ARF in the ICU require some form of renal replacement therapy (RRT).3,6,7
Access and control of resources: Lessons from the SANREM CRSP

Attention to differences within communities is important in working toward sustainability of an agro-ecosystem. In the Sustainable Agriculture and Natural Resource Management Collaborative Research Support Program, gender made a difference in terms of access and control over key resources – financial, human, natural, and social capital – critical for project success. Efforts to build social capital among women proved critical in developing both collective and households strategies for sustainability. The sites differed greatly in both landscape and lifescape. Women's position within each landscape provided an important perspective with which to assess and act toward achieving ecosystem, economic, and social sustainability.
Infrared Emission from Interstellar PAHs

The mid-infrared interstellar emission spectrum with features at 3050, 1610, 1300, 1150, and 885cm-1 (3.28, 6.2, 7.7 8.7 and 11.3 microns), spectroscopic details and continuum are discussed in terms of the Polycyclic Aromatic Hydrocarbon (PAH) hypothesis. This hypothesis is based on the similarity between the interstellar emission spectrum with the infrared absorption and Raman Spectra of PAHs and soots (collections of PAHs). The fundamental vibrations of PAHs and PAH-like species which determine the IR and Raman properties are discussed. Interstellar IR band emission is due to relaxation from highly vibrationally excited PAHs which have been excited by ultraviolet photons. The excitation/emission process is described in general and the IR fluorescence from one PAH, chrysene, is traced in detail. Generally, there is sufficient energy to populate several vibrational levels in each mode of the smallest PAHs. Molecular vibrational potentials are anharmonic and emission from these higher levels will fall at lower frequencies, producing weak features to the red of the stronger fundamentals. This accounts for some details of the interstellar emission spectra previously unexplained. Highly vibrationally excited molecules also produce a weak “quasi-continuum” that spans the entire mid-IR (4000–500cm-1, 2.5–20 microns). Analysis of the observed 3050cm-1to 2940 cm-1 intensity ratios (3.3 micron/3.4 micron) show that PAHs containing between 20 and 30 carbon atoms are responsible for the interstellar emission bands. The 885cm-1to 3050 cm-1 intensity ratio (11.3 micron/3.3 micron), which has previously been used to determine the size of the emitting PAHs, is a less appropriate measure since the 885cm-1(11.3 micron) feature is probably due to emission by fairly large PAHs (> 100 C atoms) which do not contribute much to the 3050 cm-1 (3.3 micron) band intensity.
Effect of dopamine and bromocriptine on rat ileal and colonic transport. Stimulation of absorption arid reversal of cholera toxin-induced secretion

Abstract Water and electrolyte transport were determined in rat ileum and colon using the single-pass perfusion technique. Intraperitoneal dopamine caused prompt stimulation of both ileal and colonic water absorption. The dopamine effect was mediated by both specific dopamine and α 2 -adrenergic receptors. Haloperidol, a specific dopamine antagonist, and yohimbine, an α 2 -adrenergic antagonist, inhibited the effect of dopamine in ileal absorption; both antagonists alone had no effect on basal water transport. Bromocriptine (intravenous and intraluminal) stimulated ileal and colonic water absorption, which was inhibited by haloperidol and yohimbine, and reversed cholera toxin-induced ileal secretion. Magnitude and time-courses of the increased water absorption in ileal loops inoculated with cholera toxin were the same as in loops, inoculated with saline, suggesting that bromocriptine acted to reverse cholera toxin-induced secretion by stimulating absorption. Bromocriptine had no effect on the cyclic adenosine monophosphate increase caused by cholera toxin. We conclude (a) dopamine stimulates water absorption in vivo in rat ileum and colon; (b) this dopamine effect is via specific dopamine and α 2 -receptors; (c) bromocriptine stimulates water absorption in ileum and colon and also acts by dopamine and α 2 -receptors; and (d) bromocriptine reverses cholera toxin-induced secretion.
Effects of progesterone on blood pressure, plasma volume, and responses to hypotension

Gonadal steroids have been implicated in the control of blood pressure and fluid homeostasis. These experiments test the effect of progesterone in ovariectomized ewes on blood pressure, volume, and hormone responses to hypotension. Eight ewes were each studied in four conditions: ovariectomized, progesterone and estrogen replaced, progesterone replaced, or sham treated. During each treatment mean arterial pressure (MAP), plasma volume (PV), baroreflex responsiveness, and adrenocorticotropic hormone (ACTH), arginine vasopressin (AVP), and renin responses to hypotension were determined. Progesterone treatment significantly reduced resting MAP and increased PV compared with ovariectomy or sham treatments. Heart period at 85 mmHg was reduced with progesterone treatment. There was no effect of progesterone treatment on ACTH, AVP, or renin or heart rate responses to hypotension. Basal AVP levels were increased, and angiotensin II concentrations were decreased, by estrogen and progesterone and by sham treatments; plasma Na+ also tended to be increased during these treatments. These results suggest that a small increase in progesterone can reset resting MAP and PV without altering reflex heart rate or endocrine responses to hypotension.
Raman Scattering from Vibronic Levels of a Jahn-Teller-Distorted Complex

Raman-scattering transitions have been observed between the hindered rotational states of the Jahn-Teller-distorted $^{2}E_{\mathrm{g}}$ ground state of ${\mathrm{Cu}}^{2+}$ in CaO. Impurity-induced scattering from the CaO vibrations was also observed. The results are in good agreement with the cluster model for the low-lying vibronic states.
Meissner effect and magnetic critical current density in detwinned YBa2Cu3O7−x single crystals

Abstract A simple uniaxial compression technique was used to detwin YBa 2 Cu 3 O 7− x single crystals. The Meissner effect and magnetic critical current density were measured on the same crystals before and after the detwinning treatment. Our results show that at low temperature the twin boundaries are not the primary pinning centers responsible for the high critical current density observed in the copper-oxygen plane.
Computer Modelling: A Structured Light Vision System For A Mars Rover

A computer model has been developed as a tool for evaluating the use of structured light systems for local navigation of the Mars Rover. The system modeled consists of two laser sources emanating flat, widened beams with a single camera to detect stripes on the terrain. The terrain elevation extracted from the stripe information goes to updating a local terrain map which is processed to determine impassable regions. The system operates with the beams and cameras fixed except, now and then, the beams are vertically panned to completely refresh the local map. An efficient surface removal algorithm determines the points on the terrain surface hit by rays in the bundle. The power of each reflected ray that falls on each pixel of the camera is computed using well-known optical laws.
Overexpressing TNF-alpha in pancreatic ductal adenocarcinoma cells and fibroblasts modifies cell survival and reduces fatty acid synthesis via downregulation of sterol regulatory element binding protein-1 and activation of acetyl CoA carboxylase.

The effect of tumor necrosis factor-alpha (TNF-α) gene delivery has been suggested as a potentially useful therapeutic approach to improve the chemotherapeutic treatment of patients with pancreatic ductal adenocarcinoma (PDA), but the exact mechanism of its action is not clearly understood. In this study, we analyzed the expression profile of TNF-α in PDA tissue and explored its potential role in fatty acid synthase (FAS) regulation in PDA cells and in fibroblasts. Quantitative real-time polymerase chain reaction was used to examine the expression of TNF-α in PDA, matching adjacent tissues, and benign lesions. Logistic regression models with robust variance were used to analyze the gene expression levels, and Kaplan–Meier survival curves were generated. In vitro, we overexpressed the TNF-α gene in PDA cells and fibroblasts and analyzed its effect on cell survival, migration, and on members of the FAS signaling pathway. We also evaluated TNF-α effects on a panel of inflammation-, angiogenesis-, and metastasis-related markers. In the tumor tissue of PDA patients, compared with their matched adjacent tissue, expression levels of TNF-α were not statistically different and did not correlate with survival or any other examined clinicopathological features. Overexpression of TNF-α significantly (p < 0.05) reduced PDA and fibroblast cell migration. In PDA cells that highly overexpress TNF-α, this was associated with a significant reduction of FAS mRNA and protein expression levels and significant (p < 0.05) reduction of SREBP-1 and ACC mRNA. Reduction of FAS by TNF-α was inhibited when either SREBP-1 or ACC was knocked down by siRNA. PDA cells and fibroblasts that overexpress TNF-α displayed differential regulation of several inflammation-related markers and reduced levels of metastasis-related genes. Our data demonstrate a previously unknown multi-targeted involvement of TNF-α in PDA lipogenesis and inflammation and metastasis and suggest that intratumoral introduction of TNF-α may have the potential as a novel therapeutic approach in human PDA.
Elastic Dynamic Young's Modulus and Permeability of Concrete in Fire Damaged Structural Members

This article reviews the results of two studies examining the effects of exposure to elevated temperatures on the dynamic elastic (Young’s) modulus ( Ed ) and air permeability index (API) of concrete. The relationship between Ed and API in fire damaged concrete, and the use of Ed and API to determine both the extent of damage due to exposure to fire and the presence and extent of damage gradients are reviewed. Cores were removed from a precast, prestressed concrete beam containing lightweight aggregate and from a reinforced concrete structural wall containing conventional mineral aggregates. Both of these structures were exposed to intense fires and the laboratory investigation of cores was part of a forensic engineering evaluation to determine the extent of damage to the structure and the necessary repairs prior to returning to service. The Ed and API were determined using 25 mm thick disks sawn from the cores. The findings of the study suggest that Ed and API are linearly related for a given set of raw ...
The Myth of the Myth of the New Middle Class: Some Lessons in Social and Political Theory

In his rejoinder to my essay, ‘Egypt and the Myth of the New Middle Class’, Professor Halpern clings to a limited and dysfunctional concept. The concept of NMC was of limited use in 1963 when he wrote The Politics of Social Change in the Middle East and North Africa ; since then, it hasproved to be a misleading tool for explaining the politics of change in the Middle East, yet Halpern persists in reaffirming it. For seven years, Professor Halpern has been arguing the same tautologies. On the one hand he proposes a theory of a new middle class; on the other, he explains why the NMC still has not evolved. The NMC concept is so fundamental to his book that I, for one, have examined it closely—and have found its validity and usefulness limited. Halpern writes of the need for a new theory of the relationship between social classes and system-transforming change in the modern age, but he offers no good descriptive and analytical data to support his thesis. In fact, as we shall demonstrate later, his thesis is shaken by a confrontation with rigorous empirical and correlative analyses. A cursory review of recent literature shows us many recantations by authors who once applied Grand Theories to Comparative Politics. In the spirit of the era post-Committee for Comparative Politics-neo-scholasticism, I have consented to write a rejoinder. Let me state at the beginning that I will refrain from comments on Halpern's new vintage, ‘The Dialectics of Modernization in National and International Society’, although in his rejoinder Halpern insists that the NMC has been reaffirmed and reappraised in his ‘Dialectics’. This would require more than a rejoinder. In order to review or refute Halpern's new work, I would need to write a new article, and scarcity of time does not allow me this luxury.
Neutral acetohydroxamic acid coordination to a mononuclear Ni(II) center stabilized by an intramolecular hydrogen-bonding interaction

Treatment of a new chelate ligand having both amide- and phenyl-appended pyridyl moieties with Ni(ClO4)2·6H2O and acetohydroxamic acid in methanol solution results in the production of a novel pseudo-octahedral Ni(II) complex having a neutral acetohydroxamic acid ligand stabilized by a hydrogen-bonding interaction.
The gastric mucosa in benign adenomas

Gastroscopic observations of 36 cases of benign gastric adenomatous polyps leads to the conclusion that atrophic gastritis has a seven times greater predisposition to the formation of such tumors than has the normal gastric mucosa. However, 15 of 36 patients with adenomatous gastric polyps did not have an atrophic gastritis as seen gastroscopically.
Synthesis and characterization of arene, mono- and dihydrido-arene, monohydrido-cyclopentadienyl, and phosphite complexes of molybdenum containing the tridentate ligand PhP(CH2CH2PPh2)2

Abstract The reduction of [MoCl3(TRI)], where TRI=PhP(CH2CH2PPh2)2, with sodium amalgam in benzene, toluene or anisole resulted in the formation of the corresponding [Mo(ν6-arene)(TRI)] complex. Each complex displayed a reversible one-electron oxidation in the cyclic voltammogram at ∼−1.0 V versus the ferrocenium/ferrocene couple at 0.0 V. corresponding to the oxidation of Mo(0) to Mo(1+). A second pseudo-reversible oxidation occurred at ∼0.7 V more positive. Monoprotonation of the arene complexes with CF3COOH in THF resulted in the isolation of [Mo(H)(ν6-arene)[TRI)] [CF3COO] (δ(MoH) ∼ −6 ppm). In neat CF3COOH or HBF4, evidence of diprotonation of the arene complexes was observed in the 1H NMR spectra. Upon work-up, only the monoprotonated product was isolated. [Mo(TRI)(P(OMe)3)] was formed by the reduction of [MoCl3(TRI)] in the presence of a small excess of P(OMe)3. Attempts to prepare [Mo(TRI)(PMe)3)3] by a similar method resulted in a product that readily absorbed N2 to form fac-[Mo(N2)(TRI)(PMe3)2]. Yellow [Mo(H) (ν5-C5H5) (TRI)] was formed by (i) the reduction of [MoCl3(TRI)] with sodium amalgam in the presence of cyclopentadiene, or (ii) heating fac-[Mo(N2)(TRI)(PMe3)2] with cyclopentadiene in heptane, or (iii) heating trans-[Mo(N2)2(TRI)(PPh3)] with cyclopentadiene in THF.
System identification: Regime switching, unmodeled dynamics, and binary sensors

Abstract This paper is concerned with persistent system identification for plants that are equipped with binary sensors whose unknown parameter is a random process represented by a Markov chain. We treat two classes of problems. In the first class, the parameter is a stochastic process modeled by an irreducible and aperiodic Markov chain with transition rates sufficiently faster than adaptation rates of identification algorithms. In this case, an averaged behavior of the parameter process can be derived from the stationary measure of the Markov chain and can be estimated with empirical measures. Upper and lower error bounds are established that explicitly show impact of unmodeled dynamics. In the second class of problems, the state switches values infrequently. A moving-window maximum a posterior (MAP) algorithm is introduced for tracking the time-varying parameters. Numerical results are presented to illustrate the tracking performance of the MAP algorithm and compare it with the widely used Viterbi algorithm.
SO2 – yet another two-faced ligand

Experimentally known adducts of SO2 with transition metal complexes have distinct geometries. In the present paper, we demonstrate by a bonding analysis that this is a direct consequence of sulfur dioxide acting as an acceptor in one set, square-planar complexes of d8 and linear two-coordinated complexes of d10 transition metals, and as a donor with other compounds, well-known paddle-wheel [Rh2(O2CCF3)4] and square-pyramidal [M(CO)5] (M = Cr, W) complexes. Bonding energy computations were augmented by the natural bond orbital (NBO) analysis and energy decomposition analysis (EDA). When the SO2 molecule acts as an acceptor, bonding in the bent coordination mode to the axial position of the d8 or the d10 metal center, the dominant contributor to the bonding is LAO(S) (Lewis Acidic Orbital, mainly composed of the px-orbital of the S atom) as an acceptor, while a dz2 orbital centered on the metal is the corresponding donor. In contrast, the distinct collinear (or linear) coordination of the SO2 bound at the axial position of [Rh2(O2CCF3)4] and/or [M(CO)5] is associated with a dominant donation from a lone pair localized on the sulfur atom, σ*(Rh–Rh) and/or empty LAO(M) (mainly composed of the dz2 orbital of the metal), respectively, acting as an acceptor orbital. The donor/acceptor capabilities of the SO2 molecule were also checked in adducts with organic Lewis acids (BH3, B(CF3)3) and Lewis bases (NH3, N(CH3)3, N-heterocyclic carbene).
CELLULAR REGULATION OF FETAL HEMOGLOBIN PRODUCTION

In this paper, we put together several observations from studies in erythroid cultures that suggest that the major regulatory events determining Hb F and Hb A formation in the red cells are taken at the level of erythroid stem cells. We outlined the evidence that suggests that the program of Hb F expression changes during the differentiation of the primitive progenitors, known as burst-forming units, and we raised several possibilities on how this differentiation-dependent change in developmental programs could be accomplished. Although many questions remain still unanswered, the work done so far suggests that the mechanisms of regulation of Hb F at the cellular level can be successfully probed with existing methodologies. Delineation of the cellular mechanism of Hb F regulation is required in order to find out whether the therapeutic manipulation of Hb F in the patient with Cooley's anemia is possible or not.
Preparation and characterization of carbon-coated NaVPO 4 F as cathode material for rechargeable sodium-ion batteries

Abstract Sodium vanadium fluorophosphate (NaVPO4F), a material candidate for sodium-ion battery cathodes, was synthesized via a high-temperature solid-state reaction approach. Different amounts of carbon coating were introduced in NaVPO4F to improve its electrochemical performance. The structure and morphology of the resultant cathode materials were examined by scanning electron microscopy and X-ray diffraction. The effects of carbon coating on the electrochemical performance were evaluated by cyclic voltammetry, charge–discharge curve, cycling performance and electrochemical impedance spectroscopy. The highest capacity achieved for this material was 97.8 mAh g−1 and the best capacity retention was 89% at the 20th cycle. Results demonstrated that appropriate amount of carbon coating could effectively improve the electrochemical performance of NaVPO4F, and carbon-coated NaVPO4F could offer promising future for sodium-ion battery cathode materials.
Analysis of the Constraint Joint Loading in the Thumb During Pipetting

Dynamic loading on articular joints is essential for the evaluation of the risk of the articulation degeneration associated with occupational activities. In the current study, we analyzed the dynamic constraint loading for the thumb during pipetting. The constraint loading is considered as the loading that has to be carried by the connective tissues of the joints (i.e., the cartilage layer and the ligaments) to maintain the kinematic constraints of the system. The joint loadings are solved using a classic free-body approach, using the external loading and muscle forces, which were obtained in an inverse dynamic approach combined with an optimization procedure in anybody. The constraint forces in the thumb joint obtained in the current study are compared with those obtained in the pinch and grasp tests in a previous study (Cooney and Chao, 1977, "Biomechanical Analysis of Static Forces in the Thumb During Hand Function," J. Bone Joint Surg. Am., 59(1), pp. 27-36). The maximal compression force during pipetting is approximately 83% and 60% greater than those obtained in the tip pinch and key pinch, respectively, while substantially smaller than that obtained during grasping. The maximal lateral shear force is approximately six times, 32 times, and 90% greater than those obtained in the tip pinch, key pinch, and grasp, respectively. The maximal dorsal shear force during pipetting is approximately 3.2 and 1.4 times greater than those obtained in the tip pinch and key pinch, respectively, while substantially smaller than that obtained during grasping. Our analysis indicated that the thumb joints are subjected to repetitive, intensive loading during pipetting, compared to other daily activities.
Direct regulation of ion channels by fatty acids

A variety of fatty acids regulate the activity of specific ion channels by mechanisms not involving the enzymatic pathways that convert arachidonic acid to oxygenated metabolites. Furthermore, these actions of fatty acids occur in patches of membrane excised from the cell and are not mediated by cellular signal transduction pathways that require soluble factors such as nucleotides and calcium. Thus, fatty acids themselves appear to regulate the action of channels directly, much as they regulate the action of several purified enzymes, and might constitute a new class of first or second messengers acting on ion channels.
An inexpensive, efficient cage for small birds

A simple cage system is described which is particularly applicable for housing small birds such as sparrows and finches that have been trapped in the wild. The cages are constructed of inexpensive, readily available materials.
Protein Structure Effects on Membrane Bending by Protein-Protein Crowding

Two major mechanisms of cellular membrane bending during processes such as clathrin-mediated endocytosis have been previously proposed: bending by curved protein scaffolds such as a clathrin coat, and bending by insertion of wedge-like amphipathic helices into the membrane by adaptor proteins such as epsin1. Recently we have reported a third general membrane bending mechanism; bending by protein-protein crowding, where pressure generated by densely bound proteins drives membrane bending(1). Several endocytic adaptor proteins consist of a folded N-terminal membrane binding domain, and an unfolded C-terminal domain that binds clathrin and other proteins. Due to their lack of structure, the unfolded protein domains have much larger hydrodynamic radii than folded protein domains, potentially increasing the effects of their crowding compared to proteins of equal molecular weight. We have investigated the capability of these unfolded portions of adaptor proteins to bend membranes by binding them to giant unilamellar vesicles. using a Foster resonance energy tranfer based assay of protein density, developed in our previous studies, we find that the unstructured epsin C-terminus can bend model membranes at substantially lower densities than the structured epsin N-terminal homology domain, which has traditionally been thought to drive bending. These findings suggest that concentrating unfolded domains of adaptor proteins at endocytic sites may have a previously unappreciated role in promoting membrane bending. We also find that the addition of clathrin can locally increase the concentration of epsin1 on the membrane surface. Our ongoing experiments are investigating how clathrin and adaptor proteins work together to curve membrane surfaces.(1) Stachowiak, J.C. et al., Nat. Cell Biol. 14, 944, (2012).
Gremlin is the BMP antagonist required for maintenance of Shh and Fgf signals during limb patterning

During limb outgrowth, signaling by bone morphogenetic proteins (BMPs) must be moderated to maintain the signaling loop between the zone of polarizing activity (ZPA) and the apical ectodermal ridge (AER). Gremlin, an extracellular Bmp antagonist, has been proposed to fulfill this function and therefore be important in limb patterning. We tested this model directly by mutating the mouse gene encoding gremlin (Cktsf1b1, herein called gremlin). In the mutant limb, the feedback loop between the ZPA and the AER is interrupted, resulting in abnormal skeletal pattern. We also show that the gremlin mutation is allelic to the limb deformity mutation (ld). Although Bmps and their antagonists have multiple roles in limb development, these experiments show that gremlin is the principal BMP antagonist required for early limb outgrowth and patterning.
Prospective Elementary Teachers' Use of Mathematical Reasoning in Solving a Lever Mechanics Problem

This study explored how prospective elementary teachers (n= 106, 29 groups) enrolled concurrently in elementary science and elementary mathematics methods courses used algebraic reasoning to construct and describe relationships among and between variables in the context of solving a problem involving the action of Class 1 levers. Group members collected data and tried to develop a mathematical formula that would allow them to predict where a weight of given size could be placed on one side of the lever to balance a specified weight at a specified distance from the fulcrum on the opposite side. Data sources for the study included journal entries, transcripts, and documents produced by students. Four categories encompassing the most general groupings of students' representations based on both the rule and formula were constructed. Eighteen out of the 29 groups were able to solve the problem. Specific weaknesses characterized by the solutions presented were (a) a confusion in the meaning of mathematical concepts connected with ratio and proportion; (b) a lack of mathematical language skills and/or understanding of how to symbolically represent relationships among variables in formulae; and (c) a lack of understanding of the generalizability characteristic of variables in mathematics and science.
The Interaction between Competition and Predation: A Meta-analysis of Field Experiments.

abstract: Ecologists working with a range of organisms and environments have carried out manipulative field experiments that enable us to ask questions about the interaction between competition and predation (including herbivory) and about the relative strength of competition and predation in the field. Evaluated together, such a collection of studies can offer insight into the importance and function of these factors in nature. Using a new factorial meta‐analysis technique, we combined the results of 20 articles reporting on 39 published field experiments to ask whether the presence of predators affects the intensity of competitive effects and to compare the average effects of competition and predation. Across all studies, the effects of competition in the presence of predators were less than in the absence of predators, and the interaction between competition and predation for most response variables was statistically significant. Removal of competitors had much more positive effects on organisms’ growt...
Reductive oxygenation of carbon tetrachloride: trichloromethylperoxyl radical as a possible intermediate in the conversion of carbon tetrachloride to electrophilic chlorine.

Abstract Under aerobic conditions, rat liver microsomes convert carbon tetrachloride to an electrophilic form of chlorine that is trapped with 2,6-dimethylphenol to form 4-chloro-2, 6-dimethylphenol. The mechanism of cytochrome P-450-catalyzed electrophilic chlorine formation from carbon tetrachloride was examined with structure-activity studies of electrophilic halogen formation and chemical and in vitro microsomal studies. 4-Chloro-2, 6-dimethylphenol is not formed as a consequence of a reaction of 2,6-dimethylphenoxyl radical with carbon tetrachloride or carbon tetrachloride-induced lipid peroxyl radical formation. Only tetrahalomethanes were found to yield electrophilic halogens. The chemical oxidants hydrogen peroxide, cumene hydroperoxide, sodium periodate, and iodobenzene diacetate did not support electrophilic halogen formation from carbon tetrachloride, carbon tetrabromide, or hexachloroethane in microsomal studies. The addition of superoxide dismutase, catalase, sodium azide, or glutathione to microsomal incubations did not affect the rate of electrophilic chlorine formation, whereas Paraquat completely inhibited the reaction. The radical spin trap phenyl t-butyl nitrone (14 m m ) completely inhibited electrophilic chlorine formation. The rate of electrophilic chlorine formation was highest at 2–5% atmospheric oxygen, whereas anaerobiosis completely inhibited electrophilic chlorine formation, and high oxygen tension impaired electrophilic chlorine formation. These results preclude direct oxidation of carbon tetrachloride or a reaction of superoxide anion radical with carbon tetrachloride as the initial step in electrophilic chlorine formation and suggest that the likely initial step is reductive dehalogenation of carbon tetrachloride to trichloromethyl radical which then traps oxygen to form trichloromethylperoxyl radical. Subsequent reaction of trichloromethyl peroxyl radical leads to electrophilic chlorine. These findings may have important implications concerning carbon tetrachloride-induced lipid peroxidation and carbon tetrachloride hepatotoxicity.
Chlorine demand in deep sea-water

Abstract Samples of deep sea-water were obtained at 25, 250 and 2000 m from the Sargasso Sea. The chlorine demands in these samples at any given contact time decrease with the depth at which the sample was obtained. The dissipation of chlorine occurs in two phases. The consumption rate of chlorine is similar in all three samples during the second phase at about 1 × 10 −4 mg l −1 min −1 . The difference in chlorine demand is caused primarily by the decrease in the organic chlorine demand, which occurs during the first phase of reactions, with depth reflecting the decreasing amount and increasing inertness of dissolved organic matter. The organic chlorine demands at 25, 250 and 2000 m are 0.9, 0.5 and 0.4 mg l −1 respectively. These organic chlorine demands are significantly lower than those observed in coastal sea-waters with similar dose of added chlorine of about 5 mg l −1 . If sea-waters from various depths are available, deeper sea-water would be preferred as a coolant because of its smaller chlorine demand and lower initial temperature.
A Linear-Scaling Quantum Mechanical Investigation of Cytidine Deaminase

We describe the divide-and-conquer technique for linear-scaling semiempirical quantum mechanical calculations. This method has been successfully applied to study cytidine deaminase. Large-scale simulations were performed for optimizing geometries surrounding the active site of the enzyme and obtaining related energetics. The results of the minimizations provide a significant complement to experimental efforts and aid in the understanding of the enzymatic profile of cytidine deaminase. More specifically, we present our predictions about the structure of the active species and the structure of the active site for low pH. Finally, we present our results for the structure of the zinc ion coordination for different substrates which represent points along the reaction profile. In particular, we find that our results for the Zn-S?132 and the Zn-S?129 bondlengths yield similar trends compared to x-ray crystallography data as the enzyme structure changes from the ground-state to the transition-state analog and from the transition-state analog to the product.
Genetic epidemiological studies of early-onset deafness in the U.S. school-age population

Profound, early-onset deafness is present in 4-11 per 10,000 children, and is attributable to genetic causes in at least 50% of cases. Family history questionnaires were sent to 26,152 families of children with profound, early-onset deafness not known to be related to an environmental cause. The probands were ascertained through the 1988-89 Gallaudet University Annual Survey of Hearing Impaired Children and Youth. The analysis is based on the responses that were received from 8,756 families. Classical segregation analysis was used to analyze the family data, and to estimate the proportions of sporadic, recessive and dominant causes of deafness in the families. These data were consistent with 37.2% of the cases due to sporadic causes, and 62.8% due to genetic causes (47.1% recessive, and 15.7% dominant). An earlier study using the 1969-70 Annual Survey found 49.3% sporadic cases and 50.6% genetic, demonstrating that the proportion of sporadic cases of early-onset deafness has significantly decreased since 1970.
A line weighted frequency droop controller for decentralized enforcement of transmission line power flow constraints in inverter-based networks

Recent works have shown that networks of voltage-source inverters implementing frequency droop control may be analyzed as consensus-like networks. Based on this understanding, we show that enforcement of network line power flows can be viewed as an edge-preservation problem in a Δ-disk dynamic interaction graph. Inspired by other works solving similar problems in other domains, we propose a line weighted frequency droop controller such that a network of all active buses implementing this controller enforces the specified line power flow constraints without need for communication. We provide simulation results verifying that our proposed controller limits line power to enforce constraints, and otherwise acts as a traditional droop controller.
Sex Conversion Induced by Hydrostatic Pressure in the Marine Copepod Tigriopus californicus

High hydrostatic pressure applied to the naupliar larval stages of the marine copepod Tigriopus californicus converts some individuals that would have become males into females. The copepodid stages are not sensitive to pressureinduced conversion.
The Imperative of Ethical Justification in Psychotherapy: The special case of client-centered therapy / Der Imperativ ethischer Rechtfertigung in der Psychotherapie: Der Sonderfall der Klientenzentrierten Therapie / El imperativo de la justificación ética en la psicoterapia: el caso especial de la terapia centrada en el cliente

This paper has three aims: (1) to show that every psychotherapy requires an ethical justification; (2) to provide an ethical justification for the practice of client-centered therapy that relies on...
Growth inhibition of cultured human glioma cells by beta-interferon is not dependent on changes in ganglioside composition

This investigation tested the hypothesis that the growth inhibiting effects of human beta-interferon on cultured human glioma cells involves changes in the ganglioside composition of these cells. Four cell lines derived from human malignant gliomas (12-18, U-251 MG, I29-A, 7-24) and two lines from human fetal brain (CHI, CHII) were cultured in the presence and in the absence of human beta-interferon (HuIFN-beta), 1,000 units per ml medium for three days before harvesting. Human beta-interferon had an inhibitory effect on growth of glioma but not fetal brain cells. Total ganglioside sialic acid for all cell lines ranged between 3.5 and 13.8 micrograms/10(7) cells (0.6-3.9 micrograms/mg protein). No distinct difference in the amount of total ganglioside per cell was observed between neoplastic and non-neoplastic cells, but the latter had more ganglioside per mg total protein. All cell lines displayed different patterns of gangliosides determined by high performance thin layer chromatography, but there was no distinct difference between glioma and fetal brain cells. Human beta-interferon increased the total amount of ganglioside per cell in one fetal brain and two glioma lines, but on a protein basis in only one glioma cell line (I29-A); HuIFN-beta had only minor effects on ganglioside patterns. There was a slight shift towards a greater proportion of structurally simpler gangliosides in both fetal brain and two glioma cell lines exposed to HuIFN-beta, but the reverse occurred in glioma U-251 MG. None of these changes strongly correlated with the degree of growth inhibition due to HuIFN-beta.(ABSTRACT TRUNCATED AT 250 WORDS)
Benzo(a)pyrene inhibits ovulation in C57BL/6N mice

Successful female reproductive function requires follicle growth, ovulation, and formation of the corpus luteum. Treatment of C57BL/6N mice with a single intraperitoneal injection of benzo(a)pyrene in doses ranging from 1 to 500 mg/kg produced a dose- and time-dependent decrease in the number of corpora lutea. This effect on the number of corpora lutea is most pronounced at 1 week after treatment, with a threshold of about 1 mg/kg, and an ED50 of 1.6 mg/kg. By 2 weeks after treatment partial recovery of follicle growth and ovulation occurred, as indicated by an increase in the ED50 to 20 mg/kg. Complete recovery of normal corpora lutea number occurs in mice treated with less than 100 mg/kg by 3 weeks after treatment, with little change in the ED50 noted between 3 and 4 weeks post-treatment, 78 mg/kg at both times. Mice treated with 100 or 500 mg/kg did not recover normal corpora lutea number over the course of this experiment. These data indicate that acute exposure to benzo(a)pyrene, and perhaps other polycyclic aromatic hydrocarbons, may have a transient adverse effect on follicle growth, ovulation, or formation of corpora lutea. A consequence of this effect, transient infertility, has been observed previously when exploring the effect of polycyclic aromatic hydrocarbons on murine reproduction.
NOx emission and major species concentrations in partially premixed laminar methane/air co-flow jet flames

Abstract Measurements of visible flame heights, global radiative heat loss fractions, distributions of mole fractions of stable gas species, and pollutant emission indices in laminar partially premixed flames burning various fuel-rich mixtures of CH4 and air in an overventilating co-flow of air are reported. Mole fractions of CO2, CO, H2, O2, N2, CH4, C2H4 and C2H2 were measured, using sampling and gas chromatography, at several radial locations at three different heights above the fuel tube for a fixed fuel flow rate and six different fuel tube equivalence ratios. Mole fractions of H2O were inferred from the dry based measurements. With increasing levels of partial premixing following effects are observed: (1) the visible flame height decreases and the overall flame color changes from yellow to blue; (2) the radiative heat loss fraction first decreases and then reaches a constant value; (3) the mole fractions of CO decrease and those of CO2 and H2O increase in the lean parts of the flame; (4) mole fractions of C2H2 decrease and those of C2H4 first increase and then decrease in the rich parts of the flame; (5) mole fractions of CO and H2 first decrease slightly and then increase in the rich parts of the flame; and (6) the O2 mole fractions at the point of negligible CH4 mole fraction decrease. Measurements of emission indices for NO, NOx, CO and HC show that, for a fixed fuel flow rate and overall equivalence ratio, an optimum level of partial premixing exists.
Calculating the Risks and Benefits of Disclosure in African American Women Who Have HIV

Objective To identify the processes involved in and the patterns of disclosure of their HIV diagnosis reported by African American women. Design Qualitative descriptive. Setting Southeastern United States; nurse visits in the homes of the participants. Participants Forty-eight African American women who were HIV-positive and were primary caretakers of young children. Main Outcome Measure Field notes were analyzed using content analysis. Results Once the women learned they had HIV, they were faced with the issue of determining “what is at stake” in telling others of their diagnosis. This dilemma was characterized by the threat of stigma, feelings of shame, and the concurrent need for support. The women determined a calculus of disclosure in determining to whom and when to reveal their HIV diagnosis. This calculus involved a careful evaluation of the risks and benefits involved in disclosing their illness. Risks of telling were fueled by societal and experienced stigma associated with HIV, whereas the benefits were primarily fueled by personal needs. The calculus of disclosure was a recursive process, with decisions made and remade over time. Disclosure patterns ranged from secretive to full disclosure. Conclusions Issues related to stigma and therefore to disclosure of a diagnosis of HIV are highly relevant to HIV-positive African American women. Nurses have an important role in supporting women regarding their disclosure decisions.