cssi/SciSciGPT-SciSciNet huggingface dataset:
Utilization of mevalonate by aorta for the synthesis of medium-chain n-fatty acids (C8, C10) and acylglycerols.

Abstract [2- 14 C]Mevalonate was incorporated into acylglycerols by bovine aorta. The majority of the radioactivity was found in diacylglycerols. Hydrolysis, followed by analysis by thin-layer chromatography, paper chromatography, gas chromatography, and gas chromatography-mass spectrometry showed that the radioactivity was greatest in the medium-chain n -fatty acids, caprylic (C 8 ) and capric (C 10 ) acids. Triacylglycerols and diacylglycerols have important functions in the maintenance of the metabolic integrity of organs and their constituent cells. Therefore, medium-chain fatty acids may play significant roles, such as solubilization and transport of cholesterol and regulation of metabolism, as constituents of diacylglycerols. The results suggest that the trans -methylghitaconate shunt of mevalonate metabolism functions in the aorta.
Vacuum blood-culture bottles inhibiting growth of Candida and fostering growth of Bacteroides.

Abstract The rate of isolation of Bacteroides spp. from blood-cultures increased and that of Candida spp. decreased after the use of vacuum bottles was adopted for blood-culture in a hospital. Within 3 days all vacuum blood-culture bottles inoculated with 1 × 10 2 colony-forming units of Bacteroides fragilis showed growth. However, after 10 days 87% of bottles given similar inocula of Candida spp. did not show growth. Venting the bottles produced visible growth within 6 days in all bottles inoculated with Candida spp., but there was no growth in 39% of the bottles inoculated with B. fragilis. Reports that bacillaemia caused by Bacteroides spp. is increasing and that the frequency of positive blood-cultures in disseminated candidiasis is low may be partly due to the current widespread use of vacuum blood-culture bottles.
Identification of the Antithrombin III Heparin Binding Site

The heparin binding site of the anticoagulant protein antithrombin III (ATIII) has been defined at high resolution by alanine scanning mutagenesis of 17 basic residues previously thought to interact with the cofactor based on chemical modification experiments, analysis of naturally occurring dysfunctional antithrombins, and proximity to helix D. The baculovirus expression system employed for this study produces antithrombin which is highly similar to plasma ATIII in its inhibition of thrombin and factor Xa and which resembles the naturally occurring beta-ATIII isoform in its interactions with high affinity heparin and pentasaccharide (Ersdal-Badju, E., Lu, A., Peng, X., Picard, V., Zendehrouh, P., Turk, B., Bjork, I., Olson, S. T., and Bock, S. C. (1995) Biochem. J. 310, 323-330). Relative heparin affinities of basic-to-Ala substitution mutants were determined by NaCl gradient elution from heparin columns. The data show that only a subset of the previously implicated basic residues are critical for binding to heparin. The key heparin binding residues, Lys-11, Arg-13, Arg-24, Arg-47, Lys-125, Arg-129, and Arg-145, line a 50-A long channel on the surface of ATIII. Comparisons of binding residue positions in the structure of P14-inserted ATIII and models of native antithrombin, derived from the structures of native ovalbumin and native antichymotrypsin, suggest that heparin may activate antithrombin by breaking salt bridges that stabilize its native conformation. Specifically, heparin release of intramolecular helix D-sheet B salt bridges may facilitate s123AhDEF movement and generation of an activated species that is conformationally primed for reactive loop uptake by central beta-sheet A and for inhibitory complex formation. In addition to providing a structural explanation for the conformational change observed upon heparin binding to antithrombin III, differences in the affinities of native, heparin-bound, complexed, and cleaved ATIII molecules for heparin can be explained based on the identified binding site and suggest why heparin functions catalytically and is released from antithrombin upon inhibitory complex formation.
The Spherical Transform of a Schwartz Function on the Heisenberg Group

Suppose thatK⊂U(n) is a compact Lie group acting on the (2n+1)-dimensional Heisenberg groupHn. We say that (K, Hn) is a Gelfand pair if the convolution algebraL1K(Hn) of integrableK-invariant functions onHnis commutative. In this case, the Gelfand spaceΔ:(K, Hn) is equipped with the Godement–Plancherel measure, and the spherical transform∧:L2K(Hn)→L2(Δ(K, Hn)) is an isometry. The main result in this paper provides a complete characterization of the set SK(Hn)∧={f | f∈SK(Hn)} of spherical transforms ofK-invariant Schwartz functions onHn. We show that a functionFonΔ(K, Hn) belongs to SK(Hn)∧if and only if the functions obtained fromFvia application of certain derivatives and difference operators satisfy decay conditions. We also consider spherical series expansions forK-invariant Schwartz functions onHnmodulo its center.
Dobutamine vs Furosemide in the Treatment of Cardiac Failure due to Right Ventricular Infarction

A 55-year-old man with acute inferior myocardial infarction was shown to have right ventricular involvement based on elevated jugular venous pressure, prominent A waves, and Kussmaul's sign. The ECG showed ST segment elevation in V3R with evolution of Q waves in the inferior leads. Technetium pyrophosphate images showed focal uptake in the inferior region of the left ventricle, and a radionuclide ventriculogram showed a dilated right ventricle. Administration of dobutamine, a potent inotropic agent, was associated with marked hemodynamic improvement. In contrast, the administration of diuretics was associated with hemodynamic impairment.
Type I error rates in association versus joint linkage/association tests in related individuals.

Positional gene discovery on pedigree data typically involves initial gross localization by linkage analysis with subsequent finer localization by association analysis in areas that show evidence of linkage. We examine the effect of including linkage information when testing for association in the context of variance-components-based pedigree analysis. We present simulation experiments showing that, at least in the extreme case of a rare private allele, failing to include the linkage variance component in the association model results in excessive Type I error that increases with allele copy number and/or quantitative trait locus (QTL) effect size. Joint estimation of the linkage variance component in the association model reduces Type I error to nominal expectations. This holds whether allele-sharing probabilities are estimated from a polymorphic marker or from the very single-nucleotide polymorphism (SNP) being tested for association, although the latter provides much less power. These results support the idea that an appropriate association analysis must test both the random effect of shared marker alleles (linkage) and the mean effects of the marker genotypes (association). Genet. Epidemiol. 2007. © 2007 Wiley-Liss, Inc.
Interaction of TSH, Insulin and Insulin-like Growth Factors in Regulating Thyroid Growth and Function

Primary cultures of sheep thyroid cells have been used to study regulation of thyroid growth and function by growth factors and TSH. Cells were plated at low density to minimize contributions from the endogenously produced insulin-like growth factors and their binding proteins and other proteins or hormones secreted by thyroid cells in culture. Growth of the cells was followed for 7-11 days in medium without serum. We found that TSH by itself was unable to stimulate thyroid growth. However, the ability of insulin and IGF-I to stimulate thyroid cell growth was markedly potentiated by TSH. Thyroid function was assayed by measurement of uptake of pertechnetate and organification of iodide and also by synthesis of thyroglobulin mRNA. TSH alone was unable to stimulate thyroid function appreciably. Insulin and IGF-I were ineffective by themselves at stimulating thyroid differentiated function, but in the presence of TSH, all indices were stimulated markedly. We conclude that TSH by itself is not a growth factor for thyroid cells. However, in the presence of insulin or IGF-I, TSH potentiates the growth-stimulating properties of this hormone. Similarly, TSH by itself does not stimulate thyroid function but requires the presence of insulin or IGF-I. These data show the cooperative interactions between growth factors and TSH in regulating both thyroid growth and function.
Quadratic convergence of potential-reduction methods for degenerate problems

Global and local convergence properties of a primal-dual interior-point pure potential-reduction algorithm for linear programming problems is analyzed. This algorithm is a primal-dual variant of the Iri-Imai method and uses modified Newton search directions to minimize the Tanabe-Todd-Ye (TTY) potential function. A polynomial time complexity for the method is demonstrated. Furthermore, this method is shown to have a unique accumulation point even for degenerate problems and to have Q-quadratic convergence to this point by an appropriate choice of the step-sizes. This is, to the best of our knowledge, the first superlinear convergence result on degenerate linear programs for primal-dual interior-point algorithms that do not follow the central path.
Prostate cancer: Is PSA velocity useful?

When a patient presents for assessment of prostate cancer risk, do serial measurements of PSA provide more-useful information than determination of a single PSA concentration? The authors of a new systematic review contend that the answer to this question is 'no'. Stacy Loeb cautions against hasty abandonment of PSA kinetics.
A concordance study of subareolar and subdermal injections for breast cancer sentinel lymph node mapping

Abstract Background There is disagreement regarding the preferred injection site for breast sentinel lymph node mapping. Methods The concordance of blue staining and radioactivity in the sentinel nodes of 730 consecutive patients was analyzed based on injection of mapping agents into the same or separate intradermal and subareolar sites. Results There were no significant differences in identification rates or the mean number of sentinel nodes whether agents were injected into the same or separate sites. In each group, a concordant sentinel node (both blue and "hot") was identified in >90% of patients ( P = not significant). There were no significant differences in the percentage of sentinel nodes identified as both blue and hot. Conclusions Separate subdermal and subareolar injections of mapping agents drain to the same sentinel node as often as injections into the same location. These two injection techniques appear to result in the identification of the same sentinel nodes.
Effects of Perceptions of Presence of Audience and Achievement Instructions on Performance of a Simple Task

Task performance was investigated under achievement- or nonachievement-related and real, perceived, or no-audience conditions (101 females and 19 males). The achievement conditions had no effect, but performance with both a real and a perceived audience was stronger than with no audience. Personality measures were administered to test for their moderating effects, but the results were not significant.
Effects of computer-assisted instruction on selected interaction skills related to responsible sexuality.

: This study examined effects of computer-assisted instruction on decision-making, assertiveness, and interpersonal communication related to responsible sexuality. Health science classes from four secondary schools in three mid-western states participated in the quasi-experimental study. The Experimental Group (n = 151) received simulation-based CAI, while Control Group #1 (n = 147) received regular classroom instruction, and Control Group #2 (n = 93) received no intervention. A 46-item questionnaire was administered to determine changes in the dependent variables. Findings indicated CAI, but not RCI, effectively improved decision-making knowledge and behavior, assertiveness knowledge and behavior, and interpersonal communication knowledge, attitude, and behavior. However, CAI did not improve assertiveness attitude. Over a five-week period, the effectiveness of CAI decayed for the knowledge variables. The effectiveness of CAI varied according to subject's gender, grade, and school-community setting. Results suggest simulation-based CAI provides an instructional approach that promotes positive change in some interaction skills related to responsible sexuality without many of the risks inherent in regular classroom instruction involving such sensitive topics.
TH-E-217BCD-05: Progress in Developing a Standard Reference Material for Lung CT

Purpose: Report of progress in developing a ‘standard reference material’ for tissue density variations obtained in CT scans. This effort is driven both by the mission of NIST as a standard institute, and by the activities of the RSNA COPDGene phantom design work. Methods: We continue the development effort of one set of such standards by characterizing them in a NIST traceable standard beam quality, starting by the calibration of a small ionization chamber (0.6 cc) in the NIST standard beam qualities. The chamber then becomes the transfer detector for measurements performed on a commercial CT machine. We have selected foam blocks (cut to 5 cm × 4 cm × 1.9 cm) with 5 densities ranging from 0.06 to 0.30 g/cm3, with an HU value nominally between −950 and &,minus;695. We and performed transmission measurements on four batches foams, each containing 5 densities, and each density contains 10 blocks. We extracted the linear attenuation coefficient of the foams for each the available CT energies (90, 120, and 140 kV). A small water phantom of the same transverse dimension was scanned together with the foams to obtain the attenuation coefficient of water for the HU calculation. A full CT was then performed to obtain the HU value from the machine. Results: The HU values obtained from the three energies using the transmission measurement of the foam and water vs those obtained from the full CT agreed to within 0.3% (stdm) averaged over all samples. Conclusion: We have made progress toward developing a standard reference material for lungCT applications. Physical density measurements traceable to NIST standards are underway. The transmission measurements will also be performed on the NIST M‐beams to create a correlation between the CT spectrum and the standard spectrum for these foams.
Nonlinear Evolution of Global Magnetoshear Instabilities in a Three-dimensional Thin-Shell Model of the Solar Tachocline

We investigate global instabilities of toroidal fields and differential rotation in the solar tachocline using a three-dimensional thin-shell model. We initiate our nonlinear numerical simulations by superposing random, high-wavenumber perturbations on an equilibrium state and we then allow the system to evolve freely as the instabilities develop, grow exponentially, and saturate. For broad toroidal field profiles the dominant mode is the clamshell instability previously identified in two-dimensional and shallow-water investigations in which loops of field in the northern and southern hemispheres tilt and reconnect, eventually becoming perpendicular to the equatorial plane. If the initial toroidal field is instead confined to thin bands of alternating polarity in the northern and southern hemispheres, the evolution is more complex. At early times, a previously unidentified instability occurs near the edges of each band that is characterized by a high longitudinal wavenumber m. These edge instabilities are later superseded by an m = 1 tipping instability whereby field lines tilt in latitude as in the broad-field case. The tipping instability saturates by forming a jet of fluid within each band, which provides gyroscopic stabilization. Both the clamshell and the tipping instabilities are quasi-two-dimensional and proceed most efficiently near the impenetrable boundaries where the vertical velocity vanishes. Strong stable stratification enhances this tendency by decoupling horizontal layers. These simulations demonstrate the robustness of global m = 1 instabilities in differentially rotating spherical shells threaded by toroidal magnetic fields and as such have important implications for tachocline dynamics, including dynamo processes and tachocline confinement.
A needs-driven approach to expatriate adjustment and career development: a multiple mentoring perspective

Although effective in improving socialization, development, and retention in the US domestic context, mentoring would likely benefit expatriates and their firms, but it remains theoretically underdeveloped in the international context. We develop a theory of international mentoring by integrating current perspectives on protean and boundaryless careers with the literature on mentoring and expatriates. Expatriates need multiple mentors to assist their adjustment and development during the pre-departure, expatriation, and repatriation stages of international assignments. We discuss both hierarchical and peer, and formal and informal, mentoring relationships to delineate which relationships best address specific expatriate needs. International mentoring may improve expatriate adjustment, development, and retention, and thus may affect outcomes of international strategy. We conclude by discussing implications and avenues for future research.
Financial Stress, Downturns, and Recoveries

This paper examines why some financial stress episodes lead to economic downturns. The paper identifies episodes of financial turmoil using a financial stress index (FSI), and proposes an analytical framework to assess the impact of financial stress - in particular banking distress - on the real economy. It concludes that financial turmoil characterized by banking distress is more likely to be associated with severe and protracted downturns than stress mainly in securities or foreign exchange markets. Economies with more arms-length financial systems appear to be particularly vulnerable to sharp contractions, due to the greater procyclicality of leverage in their banking systems.
DataONE member node pilot integration with TeraGrid

The NSF DataONE [1] DataNet project and the NSF Tera-Grid [2] project have initiated a pilot collaboration to deploy and operate the DataONE Member Node software stack on TeraGrid infrastructure. The appealing feature of this collaboration is that it opens up the possibility to add large scale computing as an adjunct to DataONE data, metadata, and workflow manipulation and analysis tools. Additionally, DataONE data archive and curation services are exposed as an option for large scale computing and storage efforts such as TeraGrid/XSEDE. With this joint effort, DataONE also brings an open, persistent, robust, and secure method for accessing Earth sciences data collected by science communities such as The National Evolutionary Synthesis Center's Dryad [3], The Ecological Society of America's Ecological Archive [4], NASA's Distributed Active Archive Center at the Oak Ridge National Laboratory [5], the USGS's National Biological Information Infrastructure [6], the Fire Research & Management Exchange System [7], the Long Term Ecological Research Network [8], and the Knowledge Network for Biocomplexity [9].Beginning with an April 1st, 2011, allocation, the DataONE Core Cyberinfrastructure Team has been working with the IU Quarry [10] virtual hosting service, and more generally with the TeraGrid data area, on this pilot implementation. The implementation includes multiple virtual servers in order to test different reference implementations of the common DataONE Member Node RESTful web-service functions [11]. These implementations include implementation as a Metacat server [12], as well as a Python Generic Member Node developed by DataONE [13]. The implementations will also mount TeraGrid-wide global storage services (DC-WAN [14] and Albedo [15]) and thus allow integration of input and output of large scale computational runs with wide area archival data and metadata services.
Semiclassical four-level single-atom laser

The recent single-atom microlaser experiment [K. An et al., Phys. Rev. Lett. 73, 3375 (1994)], in which a stream of inverted two-level atoms is injected into an ultrahigh $Q$ cavity, can be understood in the context of a semiclassical four-level laser model. Transit time broadening due to short atom-cavity interaction time effectively introduces nonradiative decay of the two levels in the model. The steady-state solution of semiclassical photon and atom rate equations for the intracavity mean photon number versus the intracavity atom number provides a good fit to the experimental data.
Sexually dimorphic response of the balloon-injured rat carotid artery to hormone treatment.

Background Estrogen blunts the neointimal response to vascular injury in gonadectomized rats of both sexes; addition of a progestin blocks the estrogen effect. This study tested, in intact rats of both sexes, whether (1) exogenous estrogen has a vasoprotective effect in injured carotid arteries, (2) progestin (medroxyprogesterone acetate, MPA) blocks the vasoprotective effect of estrogen, and (3) any observed sexual dimorphism in the responses to estrogen and/or MPA can be accounted for by differences in serum 17β-estradiol levels. Methods and Results Intact male and female Sprague-Dawley rats were randomly divided into four subgroups treated with either (1) 17β-estradiol, (2) MPA, (3) 17β-estradiol+MPA, or (4) vehicle and were subjected to balloon injury of the right common carotid artery. Two weeks later, rats were killed by an overdose of pentobarbital, and the carotid arteries were evaluated for myointimal thickening. Neither estradiol nor MPA altered the neointimal response in males. In females, estr...
Simulation data mining: a new form of computer simulation output

The objective of simulation modeling is to gain insight into the dynamics of complex systems. Simulation models of complex systems consist of numerous input variable, linked together by logical relationships. The process of determining the set of input variable values that produce the optima output has often posed the greatest challenge during simulation studies. In recent years, the ability to integrate optimization technology into simulation models has significantly improved this process. To effectively utilize optimization technology, however, modelers must define optimization variables. In this paper, an approach is developed that provides information concerning the interrelationship between input variables used in a simulation model. This information can then be used as the basis for selecting optimization variables.
Energetics, Locomotion, and Female Reproduction: Implications for Human Evolution

In our reconstructions of human evolution, a few key questions consistently rise to the surface. These questions tend to revolve around how the morphology of previous hominin species would have allowed them to gain access to resources during key life-history events, particularly gestation and lactation. Here the data surrounding the interactions between these key issues are assessed, making particular notes of recent advances in the fields of energetics and biomechanics as they relate to locomotion during reproduction. Reconstructions of body mass, lower limb length, and pelvic breadth suggest diverse mobility strategies for different hominin species and may offer some clues about the demographic shifts occurring in the late Pleistocene.
Changes associated with quitting cigarette smoking: the Framingham Study.

Abstract During the first 18 years of the Framingham Study there was a substantial decrease (39 per cent) in the number of men smoking cigarettes and a moderate decrease (22 per cent) in the number of women smoking cigarettes. Except for a greater tendency of diabetic patients to quit smoking, there were no significant differences at baseline between smokers who quit and smokers who continued smoking. After quitting there was a short-term rise in weight for men. This rise led only to trivial changes in blood pressure and serum cholesterol levels. There was a beneficial impact on long-term vital capacity trends from quitting smoking.
Effect of treating co-infections on HIV-1 viral load: a systematic review.

Summary Co-infections contribute to HIV-related pathogenesis and often increase viral load in HIV-infected people. We did a systematic review to assess the effect of treating key co-infections on plasma HIV-1-RNA concentrations in low-income countries. We identified 18 eligible studies for review: two on tuberculosis, two on malaria, six on helminths, and eight on sexually transmitted infections, excluding untreatable or non-pathogenic infections. Standardised mean plasma viral load decreased after the treatment of co-infecting pathogens in all 18 studies. The standardised mean HIV viral-load difference ranged from −0·04 log 10 copies per mL (95% CI −0·24 to 0·16) after syphilis treatment to −3·47 log 10 copies per mL (95% CI −3·78 to −3·16) after tuberculosis treatment. Of 14 studies with variance data available, 12 reported significant HIV viral-load differences before and after treatment. Although many of the viral-load reductions were 1·0 log 10 copies per mL or less, even small changes in plasma HIV-RNA concentrations have been shown to slow HIV progression and could translate into population-level benefits in lowering HIV transmission risk.
Automated Technique to Measure Noise in Clinical CT Examinations.

OBJECTIVE. The purpose of this study was to develop and validate an automated method to measure noise in clinical CT examinations. MATERIALS AND METHODS. An automated algorithm was developed to measure noise in CT images. To assess its validity, the global noise level was compared with image noise measured using an image subtraction technique in an anthropomorphic phantom. The global noise level was further compared with image noise values from clinical patient CT images obtained by an observer study. Finally, the clinical utility of the global noise level was shown by assessing variability of image noise across scanner models for abdominopelvic CT examinations performed in 2358 patients. RESULTS. The global noise level agreed well with the phantom-based and clinical image–based noise measurements, with an average difference of 3.4% and 4.7% from each of these measures, respectively. No significant difference was detected between the global noise level and the validation dataset in either case. It further...
Temperature dependence of Rb 5P fine-structure transfer induced by He4 collisions

Employing ultrafast laser excitation and time-correlated single-photon counting, we have measured the fine-structure transfer between Rb 5P states induced by collisions with He4 buffer gas at temperatures up to 150 °C. The temperature dependence of the binary cross section agrees with earlier measurements. Our data show that the temperature dependence of the three-body rate is about the same as that of the binary rate. The three-body rate can be described as arising from the reduction of the rubidium fine-structure splitting due to nearby helium atoms.
The "cost of caring" in youths' friendships: considering associations among social perspective taking, co-rumination, and empathetic distress.

The current research considered the costs of caring in youths’ friendships. The development of a new construct, empathetic distress, allowed for a direct test of the commonly held belief that females suffer greater vicarious distress in response to close others’ stressors and problems than do males. Empathetic distress refers to strongly sharing in a relationship partner’s distress over problems to the point of taking on the partner’s distress and experiencing it as one’s own. This new construct was examined in an ethnically diverse sample of early adolescents who responded to a series of questionnaires in their classrooms. Results indicated that girls did experience greater empathetic distress in friendships than did boys. In addition, the current research revealed that social perspective-taking in friendships (i.e., the social-cognitive ability to infer and understand the friend’s perspective) had adjustment trade-offs in that it predicted greater positive friendship quality but also greater empathetic distress in the friendship. Interestingly, the associations of social perspective-taking with both positive friendship quality and empathetic distress were partially mediated by co-rumination or excessive discussion of problems. Applied implications of the findings that girls’ greater social perspective-taking and associated co-rumination contributed both to their greater positive friendship quality but also to greater costs of caring in the form of empathetic distress are discussed.
Regulation of t helper cell differentiation by STAT molecules

It is now well appreciated that the cytokines interleukin (IL)-12 and IL-4 are important for the generation of Th1 and Th2 cells, respectively. Only recently, however, have the molecular mechanisms by which these cytokines affect Th cell differentiation begun to be defined. Previous work from our laboratory has demonstrated that members of the signal transducer and activator of transcription (STAT) gene family are critical for the differentiation of Th cell subsets. In particular, Stat4-deficient mice show an impairment in the generation of Th1 cells, whereas Stat6-deficient animals do not generate Th2 cells. We have now generated Stat4-Stat6 double-deficient mice to determine whether STAT-independent pathways exist for the development of Th cell subsets. It is surprising that Th1 but not Th2 cells can be generated from double-deficient mice in vitro and these animals are able to mount an in vivo Th1 cell-mediated immune response. These results suggest a model of Th cell differentiation in which Stat4 and Stat6 have different roles in the development of Th cell subsets.
Triggering p53 after cytokinesis failure

Cells that fail to divide during cytokinesis often arrest in the next G1 phase by a mysterious mechanism that depends upon p53. What triggers this arrest is unclear. New studies, including a report in this issue (Uetake and Sluder, 2004) suggest that this arrest does not occur because cells are polyploid, are binucleate, have multiple centrosome, or have failed cytokinesis, making this phenomenon even more puzzling.
General properties and synthesis of PWM DC-to-DC converters

General properties that interrelate network complexity, attainable conversion ratios, and switch stresses are derived for pulse-width-modulated (PWM) DC-to-DC converters. The emerging synthesis procedure guarantees that complete classes of converters that satisfy a set of prescribed specifications are generated. The input specifications include the desired DC conversion ratio, nonpulsating terminal currents, possible coupling of inductors, the allowed number of switches, and, in particular, the number of active transistor switches. As a result, a number of novel PWM topologies are uncovered. >
Aid dependence reconsidered

When foreign aid undermines institutional development aid recipients can exhibit the symptoms of aid"dependence"- benefiting from aid in the short term but damaged by it in the long term. The authors find that one equilibrium outcome can be high aid and weak institutions, even when donors and recipients fully anticipate aid's effects on institutional development, but don't take the drastic steps needed to put the country on the path to independence. Another equilibrium outcome can be low aid and strong institutions. Their model encompasses such diverse experiences as those of Tanzania and the Republic of Korea. When the development community ignores aid's effect on institutions, the outcome depends greatly on initial conditions. Where institutions are initially weak (as in many Sub-Saharan African countries at independence), institutional capacity collapses and foreign aid eventually finances the whole public budget. Where they are initially stronger, the result can be close to the institutions-sensitive equilibrium. The results suggest that, even for countries with similar per capita income, the foreign aid strategy should be designed to suit the country's institutional capacity. In some cases a short-term reduction in aid may increase a country's chances of graduating from aid.
Computer Mapping in Phenological Analysis

The development of computer methods for mapping basic geographical information provides a much needed tool for phenological analysis. In the past, phenological maps have been drawn by hand which can be both time consuming and dependent on the subjective interpretation by the analyst. The speed and complete objectivity in future analyses of phenological data through computer mapping should make it possible to convert quickly great quantities of phenological data into map form which can then be used in many decision-making processes.
Comparative study of routing metrics for multi-radio multi-channel wireless networks

The multi-radio multi-channel network architecture has been recognized as one of the promising approaches to improve the system throughput of IEEE 802.11-based multi-hop wireless networks. In this paper, we study the routing issues under this new network architecture and propose a new routing metric, called AETD (adjusted expected transfer delay). The key idea of AETD is to consider both delay and jitter of candidate routes when making the routing decision. It is designed to select a route on which hops operating on the same frequency channel are separated as far as possible. This way, interference and channel contention may be minimized along the selected route and the system throughput may be improved. Our in-depth simulation shows that the proposed AETD routing metric outperforms several other routing metrics significantly, including HOP (hop count), ETX (cumulative expected transmission count), CETT (cumulative expected transmission time), and WCETT (weighted cumulative expected transmission time)
Down syndrome: genetic recombination and the origin of the extra chromosome 21.

Despite the clinical importance of trisomy 21, we have been ignorant of the causes of meiotic nondisjunction of chromosome 21. Recently, however, genetic mapping studies of trisomy 21 families have led to the identification of the first molecular correlate of human nondisjunction; i.e. altered levels and positioning of meiotic recombinational events. Specifically, increases in 0 exchange events or in distal-only or pericentromeric exchanges are significantly increased in trisomy 21-generating meioses. These observations have led to the idea that chromosome 21 nondisjunction requires 'two hits': first, the establishment in prophase I of a 'vulnerable' bivalent and second, abnormal processing of the bivalent at metaphase I or II.
Truth, Ramsification, and the Pluralist's Revenge

Functionalists about truth employ Ramsification to produce an implicit definition of the theoretical term true, but doing so requires determining that the theory introducing that term is itself true. A variety of putative dissolutions to this problem of epistemic circularity are shown to be unsatisfactory. One solution is offered on functionalists' behalf, though it has the upshot that they must tread on their anti-pluralist commitments.
Huxtables on the Brain: An fMRI Study of Race and Norm Violation

While a substantial body of work has been devoted to understanding the role of negative stereotypes in racial attitudes, far less is known about how we deal with contradictions of those stereotypes. This article uses functional brain imaging with contextually rich visual stimuli to explore the neural mechanisms that are involved in cognition about social norms and race. We present evidence that racial stereotypes are more about the stereotypes than about race per se. Amygdala activity (correlated with negative racial attitudes in other studies) appeared driven by norm violation, rather than race. Similarly, a pattern of deactivation in the medial prefrontal cortex (previously associated with the dehumanizing of social outcasts) was connected to norm violation, not race.
Non-Abelian Debye screening: The color-averaged potential

The non-Abelian analogue of the Debye screening effect is investigated by means of perturbative calculations in high-temperature Yang-Mills theory. It is recalled that the gluon vacuum-polarization tensor, which is gauge dependent, does not directly yield the Debye screening mass beyond leading order. Instead, the correlation function of two Polyakov loops, representing the color-averaged potential energy of a static quark-antiquark pair, is examined as a possible means of defining a gauge-invariant Debye mass. Though apparently satisfactory to leading order, an examination of higher orders reveals two problems: (i) an unexpected breakdown of perturbation theory in the electrostatic sector and (ii) the emergence of the magnetostatic mass gap as the dominant decay mass of this correlation. These results might be the signal for a breakdown of gauge symmetry in the plasma phase and indicate the need for examining a gauge-invariant electrostatic correlation function that is free from color averaging.
Control Circuit Templates for Asynchronous Bundled-Data Pipelines

This paper proposes the use of templatized asynchronous control circuits with single-rail datapaths to create low-power bundled-data non-linear pipelines. First, we adapt an existing templatized control style for 1-of-N rail pipelines, the Pre-Charged Full Buffer PCFB, to bundled-data pipelines. Then, we present a novel true 4-phase template (T4PFB) that has lower control overhead. Simulation results indicate 12%-44% higher throughput for the pipeline stage equivalent to 8 to 40 gates.
Collector-up AlGaAs/GaAs HBTs using oxidized AlAs

Summary form only given. Collector-up HBTs offer a means to reduce base-collector capacitance relative to their emitter-up counterparts, and thus to improve microwave power gain and digital switching speeds. Collector-up structures afford the device designer extra latitude is choosing collector doping and are amenable to graded base designs as the base contact is now made to GaAs rather than AlGaAs. Current methods of fabricating collector-up AlGaAs/GaAs heterojunction bipolar transistors normally use either ion implantation or a three stage growth process. Here we describe a novel method for fabricating collector-up AlGaAs/GaAs HBTs. An AlAs layer is inserted into the emitter layer and is oxidized in water vapor at 450/spl deg/C. The resulting AlAs-oxide serves as a current confining layer that constricts collector current flow to the intrinsic portion of the device. Compared to conventional methods, the process of converting AlAs into an insulator in the emitter requires only one growth, and does not suffer from implant damage in the base. DC devices with typical current gains of 50 are observed.
Pipelined Execution of Critical Sections Using Software-Controlled Caching in Network Processors

To keep up with the explosive Internet packet processing demands, modern network processors (NPs) employ a highly parallel, multi-threaded and multi-core architecture. In such a parallel paradigm, accesses to the shared variables in the external memory (and the associated memory latency) are contained in the critical sections, so that they can be executed atomically and sequentially by different threads in the network processor. In this paper, we present a novel program transformation that is used in the Intelreg Auto-partitioning C Compiler for IXP to exploit the inherent finer-grained parallelism of those critical sections, using the software-controlled caching mechanism available in the NPs. Consequently, those critical sections can be executed in a pipelined fashion by different threads, thereby effectively hiding the memory latency and improving the performance of network applications. Experimental results show that the proposed transformation provides impressive speedup (up-to 9.9times) and scalability (up-to 80 threads) of the performance for the real-world network application (a 10Gbps Ethernet Core/Metro Router)
Laser in situ keratomileusis-induced optic neuropathy.

Abstract Objective To report a case of bilateral optic neuropathy after bilateral laser-assisted in situ keratomileusis (LASIK) surgery. Design Observational case report. Methods Complete eye examination with detailed evaluation of the optic nerve, detailed medical history, stereo disc photographs, GDx Nerve Fiber Analyzer testing, Humphrey 24-2 SITA visual field testing, diurnal intraocular pressure measurement, serologic evaluation, and magnetic resonance imaging of the brain and orbits. Main outcome measures Optic nerve status, visual field status, and visual acuity. Results A subject with previously healthy optic nerves had bilateral optic neuropathy develop after LASIK surgery. This neuropathy manifested with a subjective decrease in visual field, normal visual acuity, normal color vision, relative afferent pupillary defect, increased cupping of the optic nerve with focal neuroretinal rim defects, decreased nerve fiber layer thickness, and nerve fiber bundle-type visual field defects. The subject had no other risk factors for optic neuropathy. No other cause of neuropathy was identified. Conclusions Optic neuropathy is a potential vision-threatening complication of LASIK surgery. This complication may be due to barotrauma or ischemia related to extreme elevation of intraocular pressure by the suction ring. Careful examination of the optic nerve before and after LASIK surgery is warranted.
Sol-gel preparation of barium strontium titanate thin films

Barium strontium titanate, ((Ba/sub x/Sr/sub 1-x/)TiO/sub 3/), thin films of various compositions were prepared by a spin coating technique. Processing parameters were optimized to develop stable solutions which yielded crack-free films with relatively low crystallization temperatures. XRD and thermal analysis techniques were used to characterize the films and gels. The dielectric constant and dissipation factor of the films were measured as a function of temperature and frequency. Leakage current was measured as a function of voltage and time. It was determined that ethylene glycol was a necessary component of the solution to increase stability and to decrease the crystallization temperature of the films. A dielectric constant of 400 and a dissipation factor of 0.04 was measured at 1 kHz for films of the approximate composition (Ba/sub 0.8/Sr/sub 0.2/)TiO/sub 3/ with a thickness of 400 nm. Films of this composition maintained low leakage current densities for extended time periods when measured at an applied field of 0.08 MV/cm. The BST thin films therefore exhibited properties sufficient for application as DRAM capacitors.
Dislocation-based model for predicting size-scale effects on the micro and nano indentation hardness of metallic materials

In micro- and nano-indentation tests for evaluating strength and stiffness properties of engineering materials, a commonly observed phenomenon is the dependence of material properties on the indent size, also known as indentation size effect (ISE). The objective of the present work is to formulate a micro-mechanical based model based on dislocation mechanics for predicting ISE from conical or pyramidal (Berkovich and Vickers) indenters and to compare it with the most widely used Nix-Gao model. The key idea proposed here while deriving the model is a non-linear coupling between the geometrically necessary dislocations (GNDs) and the statistically stored dislocations (SSDs) that eventually allows it to simultaneously predict ISE from both micro- and nano-indentations tests on a wide range of metallic materials while the Nix-Gao model fails to do so. The work also presents a method for identifying the length scale parameter from micro- and nano-indentation experiments and also correlates it with the spacing between dislocations and thus gives a physical interpretation of the material intrinsic length scale.
Scanning Electron Microscope Investigation of Morphological Characteristics of Laboratory and Field Wear in Military Fabrics

An investigation has been made with the scanning electron microscope of the morphological characteristics of three selected military fabrics which have undergone abrasive wear on four laboratory instruments (Accelerotor, Schiefer, Stoll Flex, and Taber abraders) and in field wear situations (Ft. Lee Wear Course and/or Viet Nam missions). Cotton broke down by fibrillating, but morphology of the fibrillar bundles varied with the abradant and the application of weight and/or tension. Wear of nylon fibers also caused some breakdown via fibrillation, but morphology seemed less affected by abradants. Morphology of fiber breakdown was influenced by weave type when wear was particularly directional, as in the Stoll Flex abrader. The presence of nylon in a 70/30 nylon/cotton blend had a range of influences upon the morphology and extent of damage to cotton, depending upon the abradant utilized. The analysis of the fabrics studied to date indicates that the Accelerotor best reproduced the morphology of field wear.
The role of sleep in human declarative memory consolidation.

Through a variety of methods, researchers have begun unraveling the mystery of why humans spend one-third of their lives asleep. Though sleep likely serves multiple functions, it has become clear that the sleeping brain offers an ideal environment for solidifying newly learned information in the brain. Sleep , which comprises a complex collection of brain states, supports the consolidation of many different types of information. It not only promotes learning and memory stabilization, but also memory reorganization that can lead to various forms of insightful behavior. As this chapter will describe, research provides ample support for these crucial cognitive functions of sleep . Focusing on the declarative memory system in humans, we review the literature regarding the benefits of sleep for both neutral and emotionally salient declarative memory . Finally, we discuss the literature regarding the impact of sleep on emotion regulation .
An adaptive real-time intravehicle network protocol for intelligent vehicle systems

Intelligent vehicle systems are inherently real-time systems that must perform continuous operations, often in harsh and unpredictable environments. The real-time network infrastructure is a key technology enabler for these systems. This effort presents an adaptive real-time network protocol (ARTNP) that provides multidimensional quality-of-service support for time-sensitive data under nominal conditions and during transient surges. Transient surges (e.g., the retransmission of corrupt or lost data and the unspecified arrival of sporadic messages) are problematic in that they can temporarily overload the network, causing message transmissions to be late. ARTNP is a fully distributed protocol that specifically addresses the issue of transient surges in network loading. Under nominal conditions, ARTNP can guarantee the time constraints of any messages at optimally high levels of network utilization. During a transient surge, ARTNP will detect the surge and alter the ordering of message transmissions to sustain the timely transmission of critical messages. The CAN protocol is selected as the underlying network, because of its wide spread use in vehicular systems. Simulations compare the performance of ARTNP against an optimal nonadaptive approach.