cssi/SciSciGPT-SciSciNet huggingface dataset:
An accurate spectral method for solving the Schroedinger equation

The solution of the Lippman-Schwinger (L-S) integral equation is equivalent to the the solution of the Schroedinger equation. A new numerical algorithm for solving the L-S equation is described in simple terms, and its high accuracy is confirmed for several physical situations. They are: the scattering of an electron from a static hydrogen atom in the presence of exchange, the scattering of two atoms at ultra low temperatures, and barrier penetration in the presence of a resonance for a Morse potential. A key ingredient of the method is to divide the radial range into partitions, and in each partition expand the solution of the L-S equation into a set of Chebyshev polynomials. The expansion is called "spectral" because it converges rapidly to high accuracy. Properties of the Chebyshev expansion, such as rapid convergence, are illustrated by means of a simple example.
Synthesis of novel 21-trifluoropregnane steroids: Inhibitors of 17α-hydroxylase/17,20-lyase (17α-lyase)

Abstract Novel 21-trifluoropregnenolone ( 6 ), 21-trifluoroprogesterone ( 7 ) and related compounds 4a and 8 have been synthesized in high yields from 3β-acetoxyandrost-5-ene-17β-carbaldehyde ( 3 ). The key reaction was the conversion of 3 into the 21-trifluoromethyl-20-alcohol as a diastereomeric mixture ( 4 ) by trifluoromethyltrimethylsilane (TMS-CF 3 ) in the presence of tetrabutylammonium fluoride (TBAF). All compounds, including 6 and 7 , were unambiguously characterized by IR, 1 H and 19 F NMR, high-resolution mass spectrometry (HRMS), and elemental analysis. On this basis, we concluded that the only report of an earlier synthesis of 6 and 7 13 is erroneous. Enzyme inhibition studies showed that 20 ξ-hydroxy-21-trifluoropregn-4-en-3-one ( 8 ) is a potent inhibitor (IC 50 value = 0.6 μM) of rat 17α-hydroxylase/17,20-lyase.
Spatial variation in landscape‐level CO2 and CH4 fluxes from arctic coastal tundra: influence from vegetation, wetness, and the thaw lake cycle

Regional quantification of arctic CO 2 and CH 4 fluxes remains difficult due to high landscape heterogeneity coupled with a sparse measurement network. Most of the arctic coastal tundra near Barrow, Alaska is part of the thaw lake cycle, which includes current thaw lakes and a 5500-year chronosequence of vegetated thaw lake basins. However, spatial variability in carbon fluxes from these features remains grossly understudied. Here, we present an analysis of whole-ecosystem CO 2 and CH 4 fluxes from 20 thaw lake cycle features during the 2011 growing season. We found that the thaw lake cycle was largely responsible for spatial variation in CO 2 flux, mostly due to its control on gross primary productivity (GPP). Current lakes were significant CO 2 sources that varied little. Vegetated basins showed declining GPP and CO 2 sink with age (R 2 = 67% and 57%, respectively). CH 4 fluxes measured from a subset of 12 vegetated basins showed no relationship with age or CO 2 flux components. Instead, higher CH 4 fluxes were related to greater landscape wetness (R 2 = 57%) and thaw depth (additional R 2 = 28%). Spatial variation in CO 2 and CH 4 fluxes had good satellite remote sensing indicators, and we estimated the region to be a small CO 2 sink of -4.9 ± 2.4 (SE) g C m -2 between 11 June and 25 August, which was countered by a CH 4 source of 2.1 ± 0.2 (SE) g C m -2 . Results from our scaling exercise showed that developing or validating regional estimates based on single tower sites can result in significant bias, on average by a factor 4 for CO 2 flux and 30% for CH 4 flux. Although our results are specific to the Arctic Coastal Plain of Alaska, the degree of landscape-scale variability, large-scale controls on carbon exchange, and implications for regional estimation seen here likely have wide relevance to other arctic landscapes.
The biochemical genetics of TL antigens on mouse thymocytes

Molecules bearing thymus leukemia (TL) alloantigen were isolated by immuno-precipitation from detergent-solubilized thymocyte lysates. Antisera used included monoclonal antibodies (anti-TL. M1, anti-TL.m2, anti-TL.m3), monospecific anti-TL.5 alloantisera and multispecific anti-TL.1,2,3,5 antiserum. Apparently, each of these reagents immunoprecipitates the same single 45 000 molecular weight Tla gene product as shown by identity on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focusing and by sequential precipitation studies. Allelic TL molecules, coded by the Tlaa and Tlad genes, were shown to be distinguishable by SDS-PAGE, and tryptic peptide mapping experiments. Both allelic TL molecules could be isolated from thymocytes of (Tlaa x Tlad)F1 mice. These results suggest that, at least for the Tlaa-Tlad allelic differences, the polymorphism and antigenicity of TL is determined by variation in amino acid composition.
Simulation of the dynamic response of concrete beams externally reinforced with carbon-fiber reinforced plastic

Laboratory-scale concrete beams 3 × 3 × 30 in (7.62 × 7.62 × 76.2 cm) in size were impulsively loaded to failure in a drop-weight impact machine. The beams had no internal steel reinforcement, but instead were externally reinforced on the bottom or tension side of the beams with one-, two- and three-ply unidirectional carbon-fiber reinforced plastic (CFRP) panels. In addition, several of the beams were also reinforced on the sides, as well as the bottom, with three-ply CFRP. The beams were simply supported and loaded at beam midspan, and sustained dynamic loads with amplitudes up to 10 kips (44.5 kN) and durations less than 1 ms. Experimental measurements included total load, midspan displacement and strains, and a high-speed framing camera (10 000 frames s−1) which gave insight into the failure mechanisms. Dynamic beam behavior was also studied numerically using the finite-element method. The numerical simulations gave insight into the localized displacement behavior of the beams when subjected to an intense, impulsive load, as well as the phenomenon known as the ‘traveling plastic hinge.’ Results showed that the numerical simulations did very well in predicting the displacement-time behavior of two beam types studied in detail; a plain concrete beam and a beam reinforced with three-ply CFRP on the bottom.
C-AXIS TWIST BICRYSTAL, ARTIFICIAL AND NATURAL CROSS-WHISKER Bi2212 JOSEPHSON JUNCTIONS

We present the latest data of the c-axis bicrystal twist Josephson junctions experiments of Liet al. and of the artificial and recent natural cross-whisker junction experiments on Bi2Sr2CaCu2O8+δ (Bi2212) of Takano et al. and Latyshev et al., respectively. These combined experiments provide strong evidence for a dominant s-wave order parameter and for strongly incoherent c-axis quasiparticle tunneling in Bi2212 for T≤Tc.
SU-FF-T-346: On Using Two Parallel Opposed Fields for Grid Therapy

Purpose: To study the feasibility of creating well‐aligned opposed grid fields and to show their dosimetric advantages for grid therapy. Method and Materials: A Varian MLC(multileaf collimator) is used to create two opposed grid fields. The key in getting the two opposed beams aligned collinearly is to restrict the grid size to the region near the beam axis. A larger grid can then be assembled from a series of smaller ones, each with its own isocenter. To give a more quantitative assessment as to what the maximum size of these grid subunits can be, we choose the criterion of no crossings between neighboring rays. The dosimetry was studied by sandwiching radiographic films between phantom blocks. Results: The mathematical analysis shows that the size of each of the subunit grids is governed by the series {1/3, 1/5, 1/7,…} of the SAD (source‐axis distance), corresponding to the number of added columns; that is, two columns would reduce the “valid” grid coverage distance from the isocentric plane to 1/3 of the SAD, three columns to 1/5, and so forth. The percentage depth dose of a 1cm × 1cm opening along the beam axis is found to be 70% and 90% for the respective 6 and 18 MV photons traversing a water‐equivalent material of 30 cm thick. Conclusions: Well‐aligned opposed grid fields shaped by a MLC have been successfully demonstrated in this study. The method gives a much more dose uniformity in the areas of the grid openings as compared to a single grid field approach. This feature is important in treating a large size tumor, as such is the nature of grid application today.
Communities of Practice: Beyond Teams

Communities of practice are being incorporated by organizations into internal knowledge management schema, as well as the extended knowledge system, capable of spanning elements from the external e...
Regularization functional semi-automated incorporation of anatomical prior information in image-guided fluorescence tomography

The use of anatomical priors in fluorescence tomography is known to improve image quality and accuracy significantly. However, the use of prior information is often implemented by incorporating user segmented structural images into the optical reconstruction algorithm, a process requiring significant time and expertise. We propose an automated implementation which encodes the gray-scale prior image directly into the regularization term, eliminating the need for direct prior image segmentation, which is extendable to any spatially defined prior data. The proposed method is supported by in vivo studies.
A statistical study of the ventricular irregularity of atrial fibrillation

Abstract EKG records consisting of 2000 successive R - R intervals were obtained from 24 patients with atrial fibrillation. These records were subjected to automatic data processing routines which calculated the R - R interval histogram and related parameters and examined the relationship between neighboring intervals using the joint distribution function and other techniques. The unimodal and occasionally bimodal histograms obtained in this manner uniformly had minimum interval lengths between 300 and 500 msec and exponential right-hand tails. In half the records adjacent intervals tended to be equal in length, but adjacent intervals in the remaining records were nearly statistically independent. On the basic of the results of this study, it is suggested that the mechanism of action of the A-V node in blocking atrial impulses may be threefold: (1) a fully refractory phase after ventricular activation; (2) the ability to depolarize partially without discharging the ventricle (the phenomenon of concealed conduction): and (3) the blocking of incoming impulses by decremental conduction at the atrionodal junction.
Foundering of lower island-arc crust as an explanation for the origin of the continental Moho

A long-standing theory for the genesis of continental crust is that it is formed in subduction zones. However, the observed seismic properties of lower crust and upper mantle in oceanic island arcs differ significantly from those in the continental crust. Accordingly, significant modifications of lower arc crust must occur, if continental crust is indeed formed from island arcs. Here we investigate how the seismic characteristics of arc crust are transformed into those of the continental crust by calculating the density and seismic structure of two exposed sections of island arc (Kohistan and Talkeetna). The Kohistan crustal section is negatively buoyant with respect to the underlying depleted upper mantle at depths exceeding 40 kilometres and is characterized by a steady increase in seismic velocity similar to that observed in active arcs. In contrast, the lower Talkeetna crust is density sorted, preserving only relicts (about ten to a hundred metres thick) of rock with density exceeding that of the underlying mantle. Specifically, the foundering of the lower Talkeetna crust resulted in the replacement of dense mafic and ultramafic cumulates by residual upper mantle, producing a sharp seismic discontinuity at depths of around 38 to 42 kilometres, characteristic of the continental Mohorovicic discontinuity (the Moho). Dynamic calculations indicate that foundering is an episodic process that occurs in most arcs with a periodicity of half a million to five million years. Moreover, because foundering will continue after arc magmatism ceases, this process ultimately results in the formation of the continental Moho.
Psychological well-being of gay men with AIDS: Contribution of positve and negative illness-related network interactions to depressive mood

While the positive functions of social network interactions in ameliorating the effects of life stress are widely documented and acknowledged, a growing body of research investigations has demonstrated that social relationships can concurrently be a source of stress and that actions intended to be supportive may instead be experienced as psychologically disturbing. Data from a study of the social support experiences of gay men diagnosed with AIDS were examined to determine the contribution to the men's depressive mood of positive and negative network interactions (n = 83). Although the results are consistent with the social support literature regarding the beneficial effect of positive network interactions for seriously-ill individuals, the findings also indicate that negative illness-related network interactions are associated with decreases in depressive mood, as indicated by scores on the Center for Epidemiological Studies of Depression Scale (CES-D). The findings also demonstrate the additive effects of positive and negative network interactions and clearly point out the value of investigating the complexity and multiple functions of social interactions.
Mosquito bites and eastern equine encephalitis

Last summer, a 39-year-old man from the southeastern United States with no significant past medical history presented with high fever (104.5°F, 40.3°C), headache and photophobia with alteration of consciousness which required mechanical ventilation. His social history was significant for employment as a veterinary technician with exposure to different animals, including birds, dogs, cats, horses and cows. Cerebrospinal fluid (CSF) analysis showed high opening pressure of 38 cmH2O, normal glucose, increased protein level of 95 mg/dL (normal, 15–45 mg/dL), and significant pleocytosis of a total WBC of 975 cells/mm 3 (normal, 0–5 mg/dL)
Subdural engraftment of serotonergic neurons following spinal hemisection restores spinal serotonin, downregulates serotonin transporter, and increases BDNF tissue content in rat

Abstract Spinal hemisection injury at T13 results in development of permanent mechanical allodynia and thermal hyperalgesia due to interruption and subsequent loss of descending inhibitory modulators such as serotonin (5-HT) and its transporter (5-HT T ). We hypothesize that lumbar transplantation of non-mitotic cells that tonically secrete 5-HT and brain-derived neurotrophic factor (BDNF) will restore alterations in 5-HT and 5-HT T systems within the spinal dorsal horn. We used an immortalized rat neuronal cell line derived from E13 raphe (RN46A-B14) which is shown to secrete 5-HT and BDNF in vitro and in vivo. Three groups ( n =35) of 30 day old male Sprague–Dawley rats were spinally hemisected at T13 and 28 days later received either lumbar RN46A-V1 control empty-vector ( n =15) or RN46A-B14 ( n =15) intrathecal grafts, or no transplant. Twenty-eight days following transplantation, animals were perfused and tissue examined for changes in 5-HT, 5-HT T , and BDNF at the site of transplantation or at lumbar enlargements (L5). Immunohistochemistry revealed that RN46A-B14, but not RN46A-V1 cells, increased 5-HT tissue staining at L5 in the dorsal white matter as well as in superficial dorsal horn laminae I and II on both ipsilateral and contralateral sides, results confirmed by ELISA. Transplantation of RN46A-B14 cells significantly reduced ipsilateral 5-HT T , upregulated after injury. Significantly increased levels of BDNF were also observed after RN46A-B14 transplantation but were not localized to particular spinal laminae. These results are consistent with recovery of locomotor function and reductions in chronic pain behaviors observed behaviorally after RN46A-B14 transplantation and supports the pragmatic application of cell-based therapies in correcting damaged circuitry after spinal cord injury.
Hempel's Dilemma and domains of physics

Hempel's Dilemma is the claim that physicalism is an ill-formed thesis because it can offer no account of the physics that it refers to: current physics will be discarded in the future, and we don't yet know the nature of future physics. This article confronts the first horn of the dilemma, and argues that our knowledge of current physics is sufficient for offering a physicalist ontology of the mind. We have good scientific evidence that future physics will be irrelevant to the mind-body problem because mental processes lie safely within the well-understood domains of applicability of current physical theories.
An assay for human lymphocyte mitogenic factor: B-lymphocyte stimulation by a T-lymphocyte product.

Abstract Human lymphocyte mitogenic factor (LMF) is produced only by E-rosette positive T-lymphocytes when purified cell populations are used. Production is antigen specific and requires the presence of monocytes during the first 24 hr of culture. However, LMF production or regulation of production by cells other than T-lymphocytes may occur as more LMF activity is produced when B-lymphocytes are added to a primary culture of T-lymphocytes. The molecular weight of LMF is estimated by gel filtration to be between 20,500 and 28,000. LMF is heat stable. The response to LMF by B- or T-lymphocytes without monocytes is non-specific and is independent of and unaffected by antigen. The B-lymphocyte response is quantitatively greater that the response of T-lymphocytes. B-lymphocytes are much more sensitive to small concentrations of LMF.
Nuclear reactivity for estrogen. A possible diagnostic tool in differentiating colon cancer metastases in the ovary from primary mucinous ovarian tumors

Tissue distribution of carcinoembryonic antigen (CEA) and estrogen was analyzed in eight primary ovarian mucinous carcinomas, three primary mucinous colonic cancers, and four ovarian metastatic lesions from colonic and pancreatic adenocarcinomas. Primary ovarian mucinous carcinomas and metastatic colonic carcinomas had similar localization of CEA within the epithelial cytoplasm. Estrogen localization, in contrast, was shown within the epithelial nuclei of seven of eight primary ovarian mucinous tumors; whereas the nuclei of metastatic and primary mucinous colonic carcinomas did not have intranuclear estrogen. The cytoplasm and the stroma of both primary ovarian and metastatic colonic carcinomas stained for estrogen.
Effect of high rate deformation induced precipitation hardening on the failure of aluminium rivets

Aluminium alloy (7050-T73) rivets were fabricated by an electromagnetic riveting process. Each rivet was formed in less than 500μsec. Microcracks and severely deformed regions were observed in the rivet head. Microprobe analysis, optical and scanning electron microscopic examination on the rivets did not yield conclusive evidence that the microcracks were caused by impurities such as iron and silicon. The data obtained in this study support the view that heat generated by material flow at high speed in the rivet head induced precipitation hardening. The precipitation hardening significantly increased the material hardness in the severely deformed shear zone. It Is believed that the increment of hardness in the shear zone of the rivets fabricated from the slugs which were previously age hardened resulted in a further decrease in ductility. Hence the initiation of voids which subsequently coalesced to form microcracks in the shear zone.
Defining the mechanisms that disturb the Sm-Nd isotopic systematics of the Martian meteorites: Examples from Dar al Gani 476 and Allan Hills 77005

Microbeam studies of Martian meteorites Dar al Gani (DaG) 476 and Allan Hills (ALH) 77005 have been conducted to identify potential causes of disequilibrium exhibited in their Sm-Nd isotopic systematics. Olivine and maskelynite mineral fractions on the DaG 476 isochron are displaced relative to their positions as dictated by measured mineral compositions. The olivine mineral fractions from ALH 77005 not only have a relatively low Sm/Nd ratio, but appear to contain an unradiogenic component that shifts the olivine mineral fraction off the isochron defined by the pyroxene and maskelynite mineral fractions. Trace components such as melt inclusions, impact melt, high-Si mesostasis, and altered olivine were analyzed using scanning electron microscopy, quantitative electron microscopy, and secondary ion mass spectrometry to determine their potential for disturbing the isotopic systematics of the mineral fractions, assuming that the mineral fractions were not completely pure. Mixing models indicate that the presence of melt inclusions in the DaG 476 olivine mineral fraction lowered its Sm/Nd ratio. The maskelynite mineral fraction contains a related but more evolved mesostasis component that raised the Sm/Nd ratio of the fraction. The position of two olivine mineral fractions below the ALH 77005 isochron is interpreted to reflect small additions of impact melt with a light rare earth element enriched pattern and a non-indigenous, unradiogenic Nd component. Furthermore, the presence of rare earth elements in olivine and maskelynite from both igneous and non-igneous components such as melt inclusions, mesostasis, and impact melt is observed on a fine (<30 μm) scale. Despite the addition of this material, the Sm-Nd ages are not affected. This study demonstrates that detailed mineral separation procedures as employed by modern geochronology laboratories permit reliable ages to be derived from shocked and altered samples.
A causal analysis of error in viewsheds from USGS digital elevation models

Users of GIS are faced with the ongoing and difficult problem of estimating the validity of a GIS output given the uncertainty of the quality of digital mapped data. This research project examines the manner in which error from a digital elevation model (DEM) results in error in an estimate of a viewshed. The data set includes two DEMs for the same study area. A 10-metre DEM serves as the control model to test a United States Geological Survey (USGS) DEM. The amount and spatial pattern of the error in the test DEM is determined by comparing it to the control DEM. A viewshed analysis is then performed at a set of 61 sites. After determining the relative accuracy of the viewsheds thus estimated, a causal model of viewshed error is developed, which links the sources of the DEM error with the error in the viewshed. The most important factor in DEM error is terrain roughness. The error in the viewsheds is a result of the error being propagated from the DEM, with landscape characteristics of the viewpoinr playing a role due to their effect on the error in the DEM. The conceptual path model developed sets the stage for a quancitative approach that will attempt to predict viewshed error from the landscape characteristics without direct knowledge of the error in the DEM.
Realization and sensitivity analysis of low-loss hybrid photonic crystal waveguides using low-index dielectric materials

ABSTRACT Complex photonic bands a nd strong anisotropic disp ersion characteristics of artificially engineered periodic dielectric structures have been widely investigated. In this paper we explore the self-guiding effect possessed by photonic crystals and the possible applications for integrated photonics. Since this approach does not require a full photonic bandgap, low refractive index materials (i.e. glass or organic polymers) are considered as an alternativ e with advantages over conventional semiconductor materials. Sensitivity analysis reveals how structural variations influence the performance of this type of photonic crystal based system. Keywords : Photonic crystal, photonic bandgap, dispersion engineering, waveguide, simulation, structural deviation, feasibility, statistical analyses 1. INTRODUCTION The area of photonic crystals (PhC) and photonic bandgap (PBG) structures has been the subject of numerous research studies over the past several years. These structures could enable the engineering development of a whole new class of materials, which exhibit unique transmission properties created through an ordered arrangement of the dielectric properties
Method for locating the centromeres of mouse meiotic chromosomes and its application to t163h and t70h translocations.

Abstract A method is described for rapid differential staining of the centromeric heterochromatin of mouse meiotic chromosomes. It has been used to analyse a trivalent involving the centric fusion translocation chromosome present in T163H heterozygotes and a quadrivalent involving the reciprocal translocation chromosomes present in T70H heterozygotes.
Genistein’s Effects on Alpha7 nAChR Currents Depends upon Exposure Duration and Time Course of Expression in Xenopus Oocytes

Several previous studies that explored tyrosine phosphorylation/dephosphorylation-involvement in functional upregulation of α7-nAChRs found that genistein, a broad-spectrum inhibitor of protein tyrosine kinases (PTKs), increased Ach-evoked α7-nAChR currents. Interpretation of genistein's effects as due to perturbation of tyrosine-phosphorylation processes is complicated, however, by subsequent findings that genistein is a strong positive allosteric modulator (PAM) of α7-nAChRs. Our study asked if genistein's enhancement of α7-nAChRs currents is entirely attributable to PAM activity, or if non-PAM effects contribute as well. We compared the effects of brief (1 min) vs. extended (24 h) exposure of oocytes expressing α7-nAChRs to genistein (100 μM), both 2 and 5 days following cRNA injections (2.0 ng). On day 2, the Ach-evoked (500 μM) peak currents for control cells, and cells exposed for 1 min, or 24 h, to genistein were (mean ± SEM, nA): 29.32 ± 12.10 (n=24), 130.95 ± 35.42 (n=22), and 374 ± 105.21 (n=8). On day 5, the comparable values were: 108.61 ± 14.85 (n=10), 310.81 ± 56.22 (n=9), and 605.00 ± 128.03 nA (n=11). On day 2, 1 min genistein caused a 4.5 fold-facilitation; 24 h exposure caused a 12.8 fold-facilitation. On day 5, 1 min genistein caused a 2.4 fold-facilitation; 24 h genistein caused a 5.6 fold-facilitation. Thus, genistein-enhancement of α7 currents varied inversely with the degree of functional α7-nAChR expression, being greater for day 2 than 5. Genistein's effect on desensitization of α7-nAChR currents was also separable from facilitation. On day 2, genistein increased peak current without affecting desensitization. On day 5, genistein increased peak current and slowed desensitization. Our results suggest that genistein's enhancement of α7-nAChR currents is not entirely due to PAM effects, but involves other mechanisms too, particularly on day 2.
Fatigue failure mechanisms in polymers

Fatigue testing of polymers has revealed significant differences between the fatigue response of polymers and metals. Generally, fatigue failure in metals is a process of crack initiation, propagation, and failure. Also, fatigue damage in metals is cumulative and cycle dependent, but remains essentially independent of test frequency. Unlike that of metals, the fatigue behavior of polymers is influenced by viscoelastic effects. At high frequencies, softening and melting occur, and fatigue failure depends largely on the test frequency. At lower frequencies, fatigue failure becomes less sensitive to test frequency and results from crack initiation and propagation. These polymer characteristics arise from the production of hysteresis energy during fatigue. A portion of this energy is released as heat, some of which is dissipated, but most is absorbed in the sample, raising its temperature. This temperature rise leads to degradation of the material and a short fatigue life. Experiments were conducted to measure hysteresis energy and temperature rise for a talc-filled polypropylene. A mathematical model was developed to calculate the energy and temperature distribution during fatigue. Correlation of the temperature rise predicted by the model with that observed experimentally provided values for the various energy terms that quantitatively defined the thermomechanical fatigue response of this polymer.
ADOLESCENT HEALTH SERVICES AND CONTRACEPTIVE USE

In 1973 the Family Planning Services of the University of Pennsylvania developed a pilot project which encouraged high school students to manage their reproductive behavior over a period of time by providing them with educational and emotional incentives. Educational incentive was provided by a series of classroom discussions which emphasized attitudes personal relationship and family planning information. Emotional support was provided by encouraging students to request for free contraceptives and gynecological services at the hospital. Regular clinic visits were encouraged and dropouts were followed up. The study consisted of 161 never-pregnant high school black girls 14-18 years old; the majority belonged to low-income families (62%). On clinic visits students filled out emotional assessment forms. Results of the project showed that of the 161 students only 10% had unintended pregnancies and this was attributed to misunderstanding or misuse of the contraceptives. Also noted was the concern for regular clinic visits and support during the initial phase of contraceptive use. Older girls were also found to be more likely to have unintended pregnancies than younger girls. Results of the emotional assessment using the SCL-90 and the Hopkins Symptoms Checklist showed that the girls who got pregnant had the highest scores in depression and somatic dimensions than the rest of the study. The findings indicate that given the proper incentives adolescents who become sexually active are capable of using contraceptives effectively. It is implied that although society does not sanction adolescent use of contraceptives teenagers who are on the throes of sexual activity should at least be given the opportunity to protect themselves.
Potent Anticoagulants are Associated with a Higher All-Cause Mortality Rate After Hip and Knee Arthroplasty

Anticoagulation for thromboprophylaxis after THA and TKA has not been confirmed to diminish all-cause mortality. We determined whether the incidence of all-cause mortality and pulmonary embolism in patients undergoing total joint arthroplasty differs with currently used thromboprophylaxis protocols. We reviewed articles published from 1998 to 2007 that included 6-week or 3-month incidence of all-cause mortality and symptomatic, nonfatal pulmonary embolism. Twenty studies included reported 15,839 patients receiving low-molecular-weight heparin, ximelagatran, fondaparinux, or rivaroxaban (Group A); 7193 receiving regional anesthesia, pneumatic compression, and aspirin (Group B); and 5006 receiving warfarin (Group C). All-cause mortality was higher in Group A than in Group B (0.41% versus 0.19%) and the incidence of clinical nonfatal pulmonary embolus was higher in Group A than in Group B (0.60% versus 0.35%). The incidences of all-cause mortality and nonfatal pulmonary embolism in Group C were similar to those in Group A (0.4 and 0.52, respectively). Clinical pulmonary embolus occurs despite the use of anticoagulants. Group A anticoagulants were associated with the highest all-cause mortality of the three modalities studied.
Bird habitat mapping in the Kakadu National Park, Australia, using synthetic aperture radar (NASA/JPL AIRSAR)

The seasonally flooded forest and upland sites in the Kakadu National Park, near Jabiru, Northern Territories, Australia were the site of extensive field measurements, bird community observations and airborne remote sensing during an initial NASA/Jet Propulsion Lab AIRSAR campaign in 1993, a field visit in 1994 and combined remote sensing and field activities during the PACRIM I Project in fall 1996. The overarching purpose of these studies was to use remote sensing technology as a way to extend intensive avian biodiversity and census field observations, as well as structural vegetation measurements from a limited survey area to the regional scale. During these two visits to the Kakadu area, field measurements were made within the dominant forest types in this region, primarily mixed Eucalyptus sp . woodlands, and open- and closed-forest sites dominated by Melaleuca sp . across a range of dry to perennially-flooded sites. Bird community measurements showed vegetation structure is needed to understand habitat relationships. A major vegetation difference between the two years was an increase of 2-3 times in leaf area index at comparison sites from 1994 to 1996. The greatest LAI at any site was 2.52 in the wet Melaleuca site near Munmalary in 1994.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Cochlear blood flow in response to dilating agents

Reduced cochlear blood flow (CBF) has been implicated in various pathologies of the inner ear, including sudden deafness, noise-induced hearing loss and Meniere's disease. Thus the aim of some current therapeutic regimens to treat these conditions is to increase CBF and thereby improve oxygenation of the inner ear tissues. Most of the vasodilating agents in clinical use, however, do not have specific experimental evidence to support their effects on CBF. The hypotension which can follow systemic administration may limit their local effectiveness and general utility, just as it complicates the interpretation of the data in animal experiments. In the current study we investigated the effect of six agents, known for their systemic cardiovascular actions, on CBF: hydralazine, sodium nitroprusside, papaverine, nicotinic acid, verapamil and histamine. The effect of these drugs was studied after topical applications on the round window membrane (RWM) and systemic intravenous administrations. CBF was monitored with a laser Doppler flowmeter (LDF). Topical administration of sodium nitroprusside was the most effective in increasing CBF, followed, in order, by hydralazine and histamine. No change in CBF was observed for papaverine, verapamil or nicotinic acid. Systemic administrations of all the agents caused a marked decrease in blood pressure and variable effects on CBF. We discuss the CBF changes in relation to the different pharmacological mechanisms of action of each drug. The study demonstrates the effectiveness of topical application of vasodilating agents in increasing CBF.
Degree of Reported Speech Anxiety under Two Descriptive Conditions.

Summary Previous research has suggested that Ss' responses to fear questionnaires may vary with the degree of descriptive detail provided. In a recent study, rather wide variation in the parameters of a situational test of speech anxiety produced little difference in behavioral-physiological measures. In the present study, 263 male and female undergraduates were asked to rate their degree of discomfort about public speaking under two levels of descriptive detail. Results indicated that self-report measures were not affected by the degree of detail, at least for public speaking anxiety. In addition, data tended to support the contention that large, live audiences may not be needed in analogue research on speech anxiety.
Comparative inhibitory effects of glutamic and cysteic acids on aspartic acid utilization.

Abstract Glutamic acid inhibits the utilization of aspartic acid in reactions concerned with the biosynthesis of pyrimidines as well as threonine in Leuconostoc dextranicum 8086 and with the biosynthesis of lysine, threonine, and to some extent pyrimidines in Lactobacillus arabinosus 17-5. Cysteic acid prevents the utilization of aspartic acid in reactions involved in the biosynthesis of these end products in both organisms. Since glutamic acid does not prevent the utilization of precursors of aspartic acid such as bicarbonate and oxalacetate which reverse cysteic acid inhibition competitively, different points of action with cysteic acid probably acting subsequent to glutamic acid are involved. The synergistic effects of combinations of the two inhibitors on L. arabinosus 17-5 offers further evidence for the involvement of a sequence of inhibitions.
Anti-haemolytic effects of vitamin C.

THE possibility of inhibition of haemolysis in vitro has interested many workers. The anti-haemolytic effects, in vitro, of substances such as sucrose, cholesterol1–5, phospholipins4, plasma proteins6,7 have been repeatedly examined. The inhibitor effect of these substances has been shown on haemolysis due to different kind of lysins such as saponin, bile salts, oleate, lysolipins, streptolysin, but not, so far as I know, on haemolysis due to complement. My experiments deal with this latter type of haemolysis and with haemolysis due to saponin. The red cells used have been red sheep cells. The inhibitor substance used has been vitamin C (Roche) in vials of 1 c.c. with a pH of 6·5; each vial contained 100 mgm. of vitamin C.
Localization of Preformed, Circulating Immune Complexes in Murine Skin

The cutaneous localization of intravenously injected preformed immune complexes was examined in C57B1/6J mice and the importance of complex size and antibody charge was assessed for deposition and persistence in cutaneous structures. After a single intravenous bolus, large-latticed complexes deposited transiently in an interstitial extravasated pattern, and persisted longer in a vascular pattern. Small-latticed complexes, prepared at 50 times antigen excess, did not deposit. When large-latticed complexes were prepared with reduced and alkylated antibodies, their vascular deposition was similar, but they did not localize in the interstitium due to decreased extravasation. Large-latticed complexes prepared with cationized antibodies deposited in a vascular and interstitial pattern as well as at the dermal-epidermal junction. Complexes prepared with anionized antibodies deposited comparable to unaltered complexes. Cutaneous deposition of circulating immune complexes in mice requires a large lattice. Circulating immune complexes formed with cationic antibodies deposit at the dermal-epidermal junction.
A perchlorate sensitive iodide transporter in frogs.

Abstract Nucleotide sequence comparisons have identified a gene product in the genome database of African clawed frogs (Xenopus laevis) as a probable member of the solute carrier family of membrane transporters. To confirm its identity as a putative iodide transporter, we examined the function of this sequence after heterologous expression in mammalian cells. A green monkey kidney cell line transfected with the Xenopus nucleotide sequence had significantly greater 125I uptake than sham-transfected control cells. The uptake in carrier-transfected cells was significantly inhibited in the presence of perchlorate, a competitive inhibitor of mammalian Na+/iodide symporter. Tissue distributions of the sequence were also consistent with a role in iodide uptake. The mRNA encoding the carrier was found to be expressed in the thyroid gland, stomach, and kidney of tadpoles from X. laevis, as well as the bullfrog Rana catesbeiana. The ovaries of adult X. laevis also were found to express the carrier. Phylogenetic analysis suggested that the putative X. laevis iodide transporter is orthologous to vertebrate Na+-dependent iodide symporters. We conclude that the amphibian sequence encodes a protein that is indeed a functional Na+/iodide symporter in X. laevis, as well as R. catesbeiana.
A Comparison of Self-reported Physical Health and Health Conditions of American Indian/Alaskan Natives to Other College Students

American Indian/Alaska Natives comprise a small portion of the general college student population, but often have the poorest health and wellness, as well as the highest dropout rates compared to any other race or ethnicity. Despite the well-documented issues this group faces in higher education, they are often ignored in studies due to their status as the minority within the minority, comprising only 0.8 % of all college students in the US. This study examines the differences in college students’ overall ratings of health across racial and ethnic groups, focusing specifically on the health and wellness of AI/AN students compared to their counterparts. This paper also investigates the physical health issues students experienced in the past 12 months and the health issues’ impact on their academic achievement. Results showed that AI/AN students reported the lowest overall health ratings and the most health issues in the past year.
Adolescents tell us why teens have oral sex

Adolescents' perceived reasons why teens have oral sex ranged from physical pleasure, improving intimate relationships, reducing risks associated with vaginal sex, the influence of substances, and social factors such as reputation concerns and peer experiences.
p11 (S100A10) — an inducible adaptor protein that modulates neuronal functions

p11 (S100A10) is a member of the S100 protein family and forms a heterotetrameric complex with annexin 2. p11 has also been found to interact with a diverse set of proteins that includes several ion channels and the serotonin 5-HT1B receptor. Several factors such as dexamethasone, growth factors, nitric oxide and antidepressant therapies regulate the expression of p11. Furthermore, studies using mutant mouse models, RNA interference and antisense constructs have implicated p11 in several biological processes; in particular, there is evidence that p11 is involved in the pathophysiology underlying nociception and depression-like states.
Hypercoagulability syndromes: what the dentist needs to know.

Although many bleeding disorders, such as hemophilia, have been well characterized for many years, the knowledge of hypercoagulability syndromes is significantly less. This is the result of a long-held belief that hypercoagulability disorders were simply related to excessive amounts of the same coagulation factors that patients with bleeding disorders lacked. Now hypercoagulability disorders are better characterized and understood from a pathophysiologic mechanism. In most cases, they are distinct in pathogenesis from bleeding disorders. Patients with clearly identified specific abnormalities of clotting are diagnosed as having primary hypercoagulable states. Almost all presently recognized primary hypercoagulable disorders result from defects in proteins in either the coagulation or fibrinolytic systems. In contrast to the primary disorders, the secondary hypercoagulable disorders are much more numerous in prevalence and, in most cases, less precisely understood. Fundamental knowledge regarding the basic principles, diagnosis, and treatment of these conditions is very important for the dentist to understand,
Double-diffusive fluxes in a salt gradient solar pond

The possible influence of double-diffusive stratification on the vertical transport of salt and heat in a mixed-layer simulation model for a salt gradient solar pond is examined. The study is concerned primarily with the interfacial fluxes across the boundary between the gradient zone and upper convecting zone of solar ponds, though the arguments presented should be applicable to other ''diffusive'' interfaces as well. In the absence of mechanical stirring in the upper convecting zone (e.g., by wind), double diffusive instabilities could govern the vertical flux of heat and salt by adjusting interfacial gradients of temperature and salinity which control transport by molecular diffusion. Because these gradients are generally too sharp to be resolved by numerical models, the fluxes can either be modeled directly or be parameterized by grid-dependent ''effective diffusivities.'' It is shown that when mechanical stirring is present in the mixed layer, double-diffusive instabilities will not be allowed to grow in the interfacial boundary layer region. Thus, double-diffusive fluxes become important only in the absence of stirring and, in effect, provide a lower bound to the fluxes that would be expected across the interface.
The emergence of understanding in a computer model of concepts analogy-making

Abstract This paper describes Copycat, a computer model of the mental mechanisms underlying the fluidity and adaptability of the human conceptual system in the context of analogy-making. Copycat creates analogies between idealized situations in a microworld that has been designed to capture and isolate many of the central issues of analogy-making. In Copycat, an understanding of the essence of a situation and the recognition of deep similarity between two superficially different situations emerge from the interaction of a large number of perceptual agents with an associative, overlapping, and context-sensitive network of concepts. Central features of the model are: a high degree of parallelism; competition and cooperation among a large number of small, locally acting agents that together create a global understanding of the situation at hand; and a computational temperature that measures the amount of perceptual organization as processing proceeds and that in turn controls the degree of randomness with which decisions are made in the system.
Test and mesurement equipment for design of digital systems and devices

This article gives an overview of test and measurement solutions for design and debug of electronic devices, and the challenges that the engineers face in their day-to-day work.
Literature, Religion, and Science: A Personal and Professional Trajectory

By tracing the trajectory of his own personal and professional life, the author provides a perspective on how intellectual and religious or spiritual growth, while often seemingly at odds with each other, can nonetheless advance in a mutually enhancing manner. The historical conflict between literature and science is briefly outlined as a parallel to that between religion and science, and the importance of metaphor as a common element in all three fields is explored. Emphasis is placed on metaphor as a means of challenging absolutism, encouraging humility, and promoting a sense of wonder about the universe.
A system for sending the right hint at the right time

Hints are sometimes used in online learning system to help students when they are having difficulties. However, in all of the systems we are aware of, the hints are fixed ahead of time and do not depend on the unsuccessful attempts the student has already made. This severely limits the effectiveness of the hints.We have developed an alternative system for giving hints to students. The main difference is that the system allows an instructor to send a hint to a student after the student has made several attempts to solve the problem and failed. After analyzing the student's mistakes, the instructor is better able to understand the problem in the student's thinking and send them a more helpful hint.We have deployed this system in a probability and statistics course with 176 students. We have demonstrated the superiority of the new hints methodology over the traditional one.The limiting factor on the effectiveness of our system is the amount of manual labor required to send each hint. This is the main obstacle we see in scaling this approach to larger classes and to MOOCs. We are currently exploring several approaches for addressing this problem: 1) Letting students send hints to their peers. 2) Creating hint libraries. 3) Using machine learning methods to automate the process of mapping student mistakes to the most relevant hint.
How Disgust Enhances the Effectiveness of Fear Appeals

Abstract The current research explores the role of disgust in enhancing compliance with fear appeals. Despite its frequent use in advertising and prevalence in consumer settings, little is known about the specific role that disgust plays in persuasion. This article explores the unique characteristics of disgust and examines its distinctive effect on persuasion. The results across a series of four studies demonstrate that adding disgust to a fear appeal appreciably enhances message persuasion and compliance beyond that of appeals that elicit only fear. Importantly, the results trace the persuasive effects of disgust to its strong and immediate avoidance reaction.