cssi/SciSciGPT-SciSciNet huggingface dataset:
DEGRADATION OF PYRUVATE BY MICROCOCCUS LACTILYTICUS I. : General Properties of the Formate-Exchange Reaction.

Abstract McCormick, N. G. (University of Washington, Seattle), E. J. Ordal, and H. R. Whiteley. Degradation of pyruvate by Micrococcus lactilyticus. I. General properties of the formate-exchange reaction (J. Bacteriol. 83:887–898. 1962.—At an alkaline pH, extracts of Micrococcus lactilyticus2 catalyze the phosphoroclastic degradation of pyruvate to formate and acetyl phosphate and the rapid exchange of formate into the carboxyl group of pyruvate. At an acid pH, hydrogen, carbon dioxide, and acetyl phosphate are produced, and carbon dioxide is exchanged into the carboxyl group of pyruvate. A concentration of approximately 1 m phosphate is required for the phosphoroclastic reaction and formate exchange; the production of carbon dioxide and hydrogen is greatly inhibited by high concentrations of phosphate. Formate exchange requires a divalent metal ion and is stimulated by reducing agents and an atmosphere of hydrogen. Inhibition by p-chloromercuribenzoate, Zn++, Cd++, and arsenite indicates that sulfhydryl groups on the enzyme are involved in the reaction; the inhibition by arsenite and Cd++ may be relieved by 2,3-dimercaptopropanol, suggesting that vicinal dithiols may be required. Inhibition by hypophosphite may reflect a competition with formate for a site on the enzyme. At an alkaline pH, α-ketobutyrate is degraded to propionate and formate, whereas α-ketoglutarate is fermented to succinate, propionate, carbon dioxide, hydrogen, and formate. Formate is exchanged into the carboxyl groups of α-ketobutyrate and α-ketoglutarate under these conditions. Only traces of α-ketovalerate and α-ketoisovalerate are fermented at an alkaline pH and the exchange of formate into these compounds is very low. The addition of viologen dyes under the conditions used for formate exchange causes a reduction of pyruvate, α-ketobutyrate, α-ketovalerate, and α-ketoisovalerate to the corresponding α-hydroxy acids.
El financiamiento internacional para la cooperación al desarrollo de la salud de América Latina y el Caribe

The purpose of this study is (a) to examine the ways in which Latin America and the Caribbean (LAC) have benefited from increases in international development assistance for health (DAH) at the global level and whether the trend observed after the Millennium Summit has also applied to the Region; (b) to determine whether there are differences in the distribution of this assistance, based on the gross per capita income of each country; (c) to identify the possible effects of the 2008 international financial crisis on official bilateral assistance; and (d) to compare trends in public health expenditure in relation to DAH before and after the Millennium Summit. The study has found that DAH in LAC follows a very different pattern than in other regions of the world. The period from 1997 to 2008 was one of fluctuating stagnation, with average annual disbursements of US$ 1 200 million. Multilateral financial institutions accounted for 79% of the average disbursements in the upper-middle income countries between 2002 and 2008, while official bilateral assistance held the greatest share (61%) in the low- and lower-middle income countries. Bilateral assistance grew at an annual rate of 13% during this period, but in the year after the crisis, disbursements fell to US$ 20 million. Sixty-four percent of bilateral assistance came from the United States, Spain, and Canada, with 29% of it being directed to HIV/AIDS and sexually transmitted diseases. After the Millennium Summit DAH channeled to governments decreased 30% in the period 2001-2006, and its share of public health expenditure in the region was 0.3% for the same period, with an equally marginal proportion in relation to total health expenditure for 2008 (0.37%; US$ 2 per capita). The study concludes that after the Millennium Summit, DAH in LAC did not grow nor did it equal the trends prior to 2000, and public health expenditure followed its historical growth trend, without further increases in relation to the regional gross domestic product. Given these realities and the fact that LAC is the world's most unequal region, but not its poorest, it is imperative to reconsider the concepts, management, and delivery of cooperation in the development of health, using innovative approaches and alternative financing mechanisms that respond more effectively to the realities of the region.
Experiences with two high availability designs (replication techniques)

The author compares two replication schemes designed to provide high availability in an efficient manner: HA-NFS and ARM. Both schemes use the primary copy method for replica control. Both schemes were designed with the goal of minimizing the overheads during failure-free operation. In a primary copy scheme these overheads primarily consist of updating the secondary replicas. The two schemes were designed for different applications; ARM for providing high availability in a Shared Nothing database system, HA-NFS for providing high availability in an NFS file server environment. They also differ in that the HA-NFS scheme uses dual-ported disks to provide high availability, the ARM scheme uses replication over a network. In spite of the seemingly major differences, the schemes have the same key conceptual idea viz. propagating updates asynchronously to remote replicas. In addition to this idea, HA-NFS uses an unusual hardware arrangement in the form of dual-ported disks to further lower the overhead of updating secondary replicas. >
Through Art to Association in Japanese Politics

Bonds of Civility . Aesthetic Networks and the Political Origins of Japanese Culture. By Eiko Ikegami . Cambridge University Press, New York, 2005. 475 pp. $80, £45. ISBN 0-521-80942-8. Paper, $36.99, £20.99. ISBN 0-521-60115-0. The author explores the interrelations between the culture and politics in medieval and early modern Japan.
PSYCHOLOGICAL EFFECTS OF THE PREDICTABILITY OF PRISON RELEASE

Although the determinate sentence is generally discussed as a unified concept, it appears to be comprised of two independent factors which can be considered separately-equity in sentencing and predictability of release. This paper features one component of the determinate sentence, predictability of release, in an attempt to demonstrate the advantages of providing inmates with advance information concerning their release dates. Evidence from psychological research on stress and intrinsic motivation is presented to substantiate claims by critics of the indeterminate sentence that it results in heightened inmate-anxiety and poor program-performance. Ensuring predictability of release is an important objective which is likely to result in benefits for both inmates and the correctional system as a whole.
Television technics in graduate surgical education

Summary Television technics have tremendous major application in graduate surgical education. We have devised a multimedia display technic which has the advantages of being simple, economical, convenient, and stimulating. By combining the reportorial excellence of 35 mm color slides with the dynamic qualities of television, we have developed a unit which holds the individual's attention and communicates to him forceably. The rapid, inexpensive production of tapes permits building of a multimedia tape library. We are looking for future methods of securing two-way communication between the teacher on the television screen and the student in the television audience.
Measurement of Condensed Water Content in Liquid and Ice Clouds Using an Airborne Counterflow Virtual Impactor

Abstract Condensed water content (CWC) measured using a counterflow virtual impactor (CVI) with a Lyman-α hygrometer downstream is compared with that measured by other airborne instruments (a hot-wire probe, a PMS FSSP, and a PMS 2D-C). Results indicate that the CVI system provides a reliable measurement of CWC in both liquid- and ice-phase clouds and that the CVI measures CWC contained in both large and small hydrometeors; this means that the condensed water present in both phases and virtually all hydrometeor sizes can be measured with a single device. Small ice contents of a few milligrams per cubic meter present in cirrus clouds can also be measured by the technique.
The First Normal Stress Difference in a Shear-Thinning Motor Oil at Elevated Pressure

Currently, the only aspect of non-Newtonian behavior being modeled in lubrication is the shear dependence of viscosity. However, shear thinning is accompanied by a large difference between the normal stress in the flow direction and the cross-film direction. This stress difference can increase the load capability of a lubricant film without increased frictional penalty.A commercial 10W-40 motor oil was characterized at elevated pressures. Three different high-pressure instruments were employed: a falling-body viscometer, a thin-film Couette viscometer, and a parallel-plate rheogoniometer. Ordinary shear thinning with a second Newtonian inflection was observed. A first normal stress difference of 0.6 MPa was measured under what may be mild conditions for a crankshaft journal bearing. Elevated pressures are essential to the measurement of rheological properties that govern hydrodynamic film thickness and friction in automotive components.Time–temperature–pressure superposition was validated for the first no...
Testbed for extended-scene Shack-Hartmann and phase retrieval wavefront sensing

We have implemented a testbed to demonstrate wavefront sensing and control on an extended scene using Shack-Hartmann and MGS phase retrieval simultaneously. This dual approach allows for both high sensitivity and high dynamic range wavefront sensing. Aberrations are introduced by a silicon-membrane deformable mirror. The detailed characterization of this mirror and its sensitivity matrix are presented. The various Shack-Hartmann algorithms, including a maximum likelihood approach are discussed and compared to phase retrieval results using a point source. The next phase of the testbed will include results with extended scenes.
Embeddable random networks: method

The random networks that are formed in typical elastomer cure or cross-linking reactions obey the statistics of local chemical reactions, but it is the long-range, and not the local, properties of the structures that determine their desirable material properties. Properties such as the gel point and cycle rank are determined by the global structure of a network. Forging a connection between local statistics and global structure has been a challenging problem. Tracking the evolution of random structures during the course of cross-linking reactions has been the object of a considerable body of theoretical research. However, much of this research has ignored the space-filling requirements of the resulting statistically branched structures. As especially emphasized by Gordon and co-workers, the chemical structures that are formed in typical cross-linking reactions can be understood within the context of graph theory. However, a pure mathematical graph has no metrical information, which means that any information on the embedding of the graph in three-space will be impossible to infer from the graph alone. Here it is shown that one can introduce physically meaningful metrical information on the graph structure by imposing a spatial distribution of cross-links and chains from the beginning. This ensures that the resulting statistical networks are capable of being embedded in the space of that generates the distribution.
Differential Effects of p-Chloromercuriphenyl Sulfonate on Arterial Responses to Epinephrine and Serotonin

SummaryThe purpose of this study was to gain insight into the role of sulfhydryl (SH) groups in arterial receptors for vasoactive simulants. We studied the effects of p-chloromercuriphenyl sulfonate (PCMBS, 10-6 to 10-4 M), a potent and specific SH binding agent, on contractile responses produced with 10-5M epinephrine and 10-5M serotonin in helical strips of arterial smooth muscle prepared from tail arteries of the rat. Responses to epinephrine were rapidly, markedly, and reversibly inhibited with low concentrations of PCMBS. In contrast, responses to serotonin were slowly inhibited when high concentrations of PCMBS were tested. The inhibitory effect of PCMBS (10-5M) on epinephrine-induced contractions was prevented by 10-3 M cysteine. Alpha-adrenergic blockade with phentol-amine (10-4 or 5 × 10-6 M) virtually abolished responses to epinephrine and significantly decreased responses to serotonin. These findings are consistent with the view that arterial receptors for contractile responses to epinephrine a...
Comparison of Fetal Human Liver with Cord Blood Hematopoietic Stem Cell BFU-E Colony Formation in Response to Human Erythropoietin

Comparison of Fetal Human Liver with Cord Blood Hematopoietic Stem Cell BFU-E Colony Formation in Response to Human Erythropoietin
Permanent effects of estradiol on cellular metabolism of the developing mouse vagina.

Abstract Persistent, hormone-independent vaginal proliferation is produced when estradiol is given to mice during a discrete period following birth. Synthesis of DNA, RNA, and protein in the altered vaginae has been investigated. An increased rate of cell multiplication in vaginae from adult animals, given estradiol in the newborn period, is indicated by increased incorporation of thymidine- 3 H into DNA. Incorporation of labeled amino acids into vaginal protein is accelerated, as is incorporation of uridine- 3 H into total organ RNA. Vaginal RNA, labeled in vivo with 32 P, was fractionated by extraction at three temperatures. The results of thermal fractionation suggest that the permanent estradiol-induced changes in vaginae are accompanied by selective effects on some RNA species, either in terms of relative rates of synthesis or in qualitative differences of RNA moieties. Vaginae from mice, given estradiol in the newborn period, retain selective uptake and prolonged retention of 3 H-labeled estradiol and the capacity to respond to exogenous estradiol with increased incorporation of labeled amino acids into protein. The vaginal epithelium remains capable of both mucin and keratin production. These studies demonstrate that persistent alterations of cellular metabolism accompany the morphological sequelae seen in vaginae from mice given estradiol during a defined neonatal period. Rates of synthesis of DNA, RNA and protein are permanently altered, while some normal characteristics and hormone-specific responses of vaginae are unaffected.
Identifying high amenity zones in the U.S. and China with advanced GIS techniques

This paper applies a variety of GIS techniques to examine the spatial pattern and extent of high amenity zones (HAZ) in selected cities of the U.S. and Guangzhou, China. HAZs are adjacent to downtowns and represent high density upscale residential areas whose residents support neighborhood retailing and service employment that can often result in the misclassification of the areas as employment centers. To define the HAZ consistently across U.S. cities, we first develop a weighted median job density measure for the census tracts of each city and include census tracts that are in the upper quartile in job density and have an employment residence ratio below 1.25, the critical value used to define job centers. In the absence of employment data for China at a census tract scale, Starbucks coffee houses are mapped as they were found in an earlier study to be spatially coincident with high amenity zones in the U.S. Google Earth and GPS field work allowed us to locate each Starbucks for Guangzhou China. Preliminary findings from Guangzhou and the designation of its Tian He District as an HAZ allows for some cross cultural comparisons of the HAZ concept.
Genetic Testing Likelihood: The Impact of Abortion Views and Quality of Life Information on Women’s Decisions

Little is known about factors predicting the likelihood of choosing genetic testing in college aged women versus older women, including knowledge of quality of life (QOL) associated with a disorder. Using vignettes with female college students (Experiment 1: n=257, mean age=19.70 yrs) and female faculty/staff/alumni (Experiment 2: n (nulliparous)=83, mean age=30.20 yrs; n (mothers)=53, mean age=33.77 yrs), we examined the contribution of multiple factors to predicting genetic testing likelihood for cystic fibrosis. We investigated malleable situational factors (style of genetic risk presentation and providing QOL information including physical and social aspects) and stable dispositional factors (abortion views). Parity (i.e., prior births) was more influential in women's genetic testing likelihood than was age. Greater acceptability of abortion for oneself and self-assessed knowledge following QOL information were predictors of higher testing likelihood for college students. Greater acceptability of abortion for another person was a predictor for nulliparous women. Abortion views moderated the effect of predictors for nulliparous women and mothers. Findings encourage genetic counselors to utilize QOL information to promote informed decision making through genetic testing.
Effect of latency on calculated complication rates

Late complications of radiation therapy and other cancer therapies may not always be expressed because of the shortened survival of cancer patients. Methods for estimating the true complication rate must account for censoring of the data. Actuarial methods give the time-dependent probability of remaining free of the injury. However, these methods fail when the last surviving patient develops a complication. This study describes a different method for calculating the corrected complication rate. One advantage is that the method does not produce estimates of 100% for the complication rate that occur using the actuarial method when the last survivor suffers a complication. To use the method presented here, the distribution of latent periods of the injury and the survival function for the patients at risk must be identified.
Measurement of human serum albumin in microgram amounts by solid-liquid ligand partition

When [3H]stearic acid and human serum albumin are introduced in aqueous phase into polyethylene vials, a certain fraction of the fatty acid initially present in solution is tightly bound to the protein, while most of the fatty acid remaining, i.e., unbound fatty acid, is adsorbed onto the surface of the containers. We have developed a highly sensitive HSA assay which is based on this phenomenon. Under our experimental conditions, the amount of radioactivity present in aqueous phase is directly proportional to the amount of HSA in solution. The method was tested by measuring HSA in sera obtained from 42 normal ambulatory volunteers. The results compare very favorably with parallel data obtained by the measurement of HSA in the same sera by either a bromcresol green (BCG) method or a single radial immunodiffusion (SRID). Our assay also met a number of other criteria for specificity, precision, and/or accuracy. The method permits the detection of as little as 3 μg of HSA. Various ligands also known to interact with HSA, such as bilirubin, dicumarol, digitoxin, digoxin, and Warfarin, did not affect our results when present at credible concentrations in our assay system.
A CLARIFICATION OF THE CONCEPTS OF “INCOME,WEALTH BASE, AND RATE OF RETURN IMPLICATIONS OF ALTERNATIVE PROJECT EVALUATION CRITERIA”

ABSTRACT A recent paper by Bemhard [The Engineering Economist, 38 (Spring 1993) 3, pp. 165–176([ asserts that the NPV decision criterion, and by implication the NPV measure of worth, which is part of the decision criterion, implies a different “investment” and “project income” (return) than the IRR decision criterion, except when the internal rate(s) of return are equal to the external rate(s) of return. In this paper, it is demonstrated that both the IRR decision criterion and the NPV decision criterion assume that the capital that remains invested (or borrowed) in an opportunity grows at the IRR of the opportunity and cash released by the decision about the opportunity would he invested to grow at the decision maker's marginal growth rate (or “external” rate).
On the capacitance of metal/high-k dielectric material stack/silicon structures

Abstract The accumulation capacitance of metal–insulator–Si capacitors with SrTa 2 O 6 , ZrSiO 4 -based high- k gate dielectrics is observed to have significantly different dependence on the temperature and the frequency of a capacitance–voltage measurement than that of the conventional metal–oxide–Si capacitors. It is shown that this is due to contributions from the, often, inadvertently grown, and relatively poorer quality interfacial dielectric between the high- k material stack and the Si substrate.
Multimodel Estimates of Atmospheric Response to Modes of SST Variability and Implications for Droughts

Abstract A set of idealized global model experiments was performed by several modeling centers as part of the Drought Working Group of the U.S. Climate Variability and Predictability component of the World Climate Research Programme (CLIVAR). The purpose of the experiments was to assess the role of the leading modes of sea surface temperature (SST) variability on the climate over the continents, with particular emphasis on the influence of SSTs on surface climate variability and droughts over the United States. An analysis based on several models gives more creditability to the results since it relies on the assessment of impacts that are robust across different models. Coordinated atmospheric general circulation model (AGCM) simulations forced with three modes of SST variability were analyzed. The results show that the SST-forced precipitation variability over the central United States is dominated by the SST mode with maximum loading in the central Pacific Ocean. The SST mode with loading in the Atlanti...
Pragmatics and Definite Descriptions

One philosophical logician will take the current system of formal logic itself as the firm base from which to direct all his ordering operations against the unruly tribes of language, all his explanatory manoeuvres among the diverse phenomena of speech. Another will start — as far away as possible from this base — by examining those phenomena themselves in all their particularity and detail. Will the true order be achieved when the adherents of both approaches are folded in a single party, when we have a theory of meaning firm enough and rich enough to accommodate in a single, unified account both the simplicity of logical laws and the diversity of linguistic phenomena? Perhaps it will — if there is such a thing as the true order.1
Dipyridocatecholate-Bridged Complexes of Platinum and Ruthenium Diimine Chromophores.

New Ru−Pt heterometallic complexes have been prepared and their electrochemical and luminescence properties characterized. One series of complexes contains a tris diimine-chelated Ru(II) center linked to one, two, or three Pt(II) diimine moieties via a dipyridocatecholate (dpcat; 1,10-phenanthroline-5,6-diolate) bridging ligand, as indicated by the general formula [(dbbpy)3-nRu((μ-dpcat)Pt(dbbpy))n](PF6)2 (n = 1−3) where dbbpy = di-tert-butylbipyridine. A different dinuclear complex has a tetrapyridophenazine (tppz) bridge connecting a Ru(diimine)32+ chromophore with a Pt diimine dithiolate center and has the formula [(dbbpy)2Ru(μ-tppz)Pt(tdt)]2+ where tdt = toluene-3,4-dithiolate. The dpcat-bridged complexes exhibit numerous redox processes that are assigned on the basis of comparison of those shown by mononuclear precursors and analogues, i.e., Ru(diimine)32+ and Pt(dbbpy)(dpcat). The dpcat-bridged complexes display distinct absorption bands due to Ru(diimine)32+ and Pt(diimine)(diolate) chromophores at...
Inaccuracies due to sample-solvent interactions in high-performance liquid chromatography

Abstract Inaccuracies in quantitation by high-performance liquid chromatography (HPLC) due to sample—solvent interactions are described for two compounds, van
Bungee jump model with increased stretch-prediction accuracy

This bungee jumping model improves the stretch prediction accuracy of prior models by including the effects of: rubber viscoelasticity, stiffness nonlinearities, jumper air drag, and jumper horizontal push-off. Bungee (bungy) cords are made from rubber, a viscoelastic material whose stiffness is a function of the number of cycles (cycle effect), the time interval since the last cycle (interval effect), strain rate, and temperature. Stiffness was measured, on an MTS machine, over 100 cycles at four intervals (1, 5, 60, 1440 min), three strain rates (0.17, 1.5, 5.0 s−1) and constant temperature (20.5°C). At a constant cycle interval and strain rate, rubber stiffness decreased 9.8% from the 10th to the 100th cycle. This decrease was linear with the logarithm of the cycle number. Stiffness recovered 6.5% after 24 hours of non-use. Neglecting viscoelastic effects causes significant stretch-prediction errors of -11.0% (cycle effect), -3.2% (interval effect), and +1.6% (strain rate). Less significantly, neglecting jumper air drag, jumper push-off, and stress-strain nonlinearities cause prediction errors of +1.9%, +0.7%, and +0.2%, respectively. These errors are based on a typical cord, of unstretched length 7.5 m, that elongates 250%. For accurate stretch prediction, with typical sized bungee cords, viscoelastic effects are both more important and easier to implement than air drag and stress-strain non-linearity.
Analysis of methyl iodide, methyl nitrate, and methyl alcohol in 20 M nitric acid by gas chromatography

Abstract A method for the determination of methyl iodide, methyl nitrate, and methyl alcohol in 20 M nitric acid solutions by gas chromatography has been developed. The separation and subsequent determination is dependent upon proper conditioning of the column with water. Satisfactory determinations have been carried out in aqueous and 20 M nitric acid media.
Risk Factors for Meningitis Following Cerebral Angiography: A Case-Control Study

BACKGROUND/OBJECTIVES: During May-August 2004, an increased rate of meningitis was noted among patients admitted to Shands Hospital (SH) with intracranial hemorrhage or cerebral aneurysms, and who underwent angiography and embolization of the cerebral vasculature. Infection control initiated an investigation to (i) determine the cause of the outbreak; (ii) identify associated risk factors; and (iii) implement appropriate control measures. METHODS: An epidemic curve was constructed for January-October 2004 (study period) followed by a retrospective case-control study. Also, observational studies were conducted to assess practices and procedures. A case was defined as any adult patient who acquired meningitis after undergoing cerebral angiography during the study period. Cases were ascertained through review of patient medical charts and microbiology records. Data were recorded in a standardized questionnaire and included age, sex, severity of illness scores, prior hospitalization, medical device usage, duration of hospitalization, co-morbidities, administration of pre-angiography antimicrobial prophylaxis, surgeon, and outcome (death or survived). Odds ratios (OR) and 95% confidence intervals (CI) were calculated. Fisher's exact test was used, where appropriate. RESULTS: Post-operative meningitis rates in pre-epidemic and epidemic periods were 3.1% and 18.5%, respectively (p 32, p CONCLUSIONS: Patients who acquired meningitis following angiography at SH during the study period appeared to have intrinsic risk factors associated with severity of the intracranial hemorrhage. Neither coiling procedures nor the surgeons who performed the angiography were found to be associated risk factors as was presumed. Moreover, receipt of pre-angiography antimicrobials appeared not to be protective against the acquisition of meningitis. Obese patients with severe intracranial hemorrhage transferred from an outside hospital were at increased risk of meningitis post angiography. Lennox K. Archibald, MD, FRCP, Rengeration Technologies Inc, Employee. Also please note: A version of this abstract was also submitted to SHEA 2006.
An ABCD program to increase access to dental care for children enrolled in Medicaid in a rural county.

Objectives: The Access to Baby and Child Dentistry (ABCD) Program addresses the needs of families in obtaining dental care. In this study, the program was evaluated in rural Stevens County, Washington. Aims were to assess utilization of dental services, average dental expenditures per child, and oral health status. Methods: Medicaid-enrolled children aged 1–4 years were randomly assigned to the ABCD program (n=216) or to regular benefits (n=221). An outreach worker contacted each ABCD family and provided an orientation. Dental care utilization and expenditures were calculated from claims. A posttest-only design was used to evaluate oral health status. Results: An enrollment effect was seen in ABCD, but the difference between groups was not sustained. There was a doubling of utilization between groups for the youngest cohort, while the others showed no differences. In the first year the rate was higher for the entire ABCD group than for the children not in ABCD (34.0% vs 24.7%). Thirty-three percent of ABCD children (70/212) who had visited the dentist had >1 appointment compared to 21.5 percent (47/219) for the children not in ABCD who had visited the dentist. There was no overall difference in expenditures, while expenditures for preventive services were greater for ABCD. ABCD children had fewer teeth with initial caries. The average incremental cost per child per initial lesion prevented was $31.44. Conclusion: ABCD most benefited the youngest cohort of children and improved health.
Children's exposure to community violence.

PURPOSE: To analyze the effects of exposure to chronic community violence on children and adolescents. DESIGN: An integrative review of the literature was conducted on reports of studies about children's exposure to community violence. SOURCES: Studies for analysis were identified through a literature search of relevant topics in Medline, CINAHL, and PsycINFO. CONCLUSIONS: Exposure to community violence is related to significant stress and depression in children. Evidence on how exposure to violence affects children's growth patterns, intellectual growth, school performance, decision-making ability, or their hope for a future is needed. Language: en
Duplicated proteasome subunit genes in Drosophila and their roles in spermatogenesis

The proteasome is a large, multisubunit complex that acts as the cell's ‘protein-degrading machine’ in the ubiquitin-mediated proteolytic pathway for regulated protein turnover. Although proteasomes are usually thought of as being homogeneous structures, recent studies have revealed their more dynamic and heterogeneous nature. For example, in a number of plant and animal species, multiple isoforms of several proteasome subunits, encoded by paralogous genes, have been discovered, and in some cases, these alternative isoforms have been shown to be functionally distinct from their conventional counterparts. A particularly striking example of this phenomenon is seen in Drosophila melanogaster, where 12 of the 33 subunits that make up the 26S proteasome holoenzyme are represented in the genome by multiple paralogous genes. Remarkably, in every case, the ‘extra’ genes are expressed in a testis-specific manner. Here, we describe the extent and nature of these testis-specific gene duplications and discuss their functional significance, and speculate on why this situation might have evolved.
The effects of personality tests on state and trait anxiety.

Summary 52 college student volunteers received the MMPI, Rorschach, TAT, and Sentence Completion Test in counterbalanced order with a test-retest interval of approximately 24 hours. State and trait anxiety measures were assessed immediately prior to and immediately following each test administration. Results indicated that state anxiety measures increased significantly following administration of the more ambiguous, unstructured test stimuli, namely the Rorschach and TAT. In contrast, the more structured, direct assessment methods, namely the MMPI and Sentence Completion Test, did not induce any significant changes in state anxiety. In all cases, trait anxiety measures remained relatively stable.
Crystal Structure of the Pleckstrin Homology Domain from the Ceramide Transfer Protein: Implications for Conformational Change upon Ligand Binding

Ceramide transfer protein (CERT) is responsible for the nonvesicular trafficking of ceramide from the endoplasmic reticulum (ER) to the trans Golgi network where it is converted to sphingomyelin (SM). The N-terminal pleckstrin homology (PH) domain is required for Golgi targeting of CERT by recognizing the phosphatidylinositol 4-phosphate (PtdIns(4)P) enriched in the Golgi membrane. We report a crystal structure of the CERT PH domain. This structure contains a sulfate that is hydrogen bonded with residues in the canonical ligand-binding pocket of PH domains. Our nuclear magnetic resonance (NMR) chemical shift perturbation (CSP) analyses show sulfate association with CERT PH protein resembles that of PtdIns(4)P, suggesting that the sulfate bound structure likely mimics the holo form of CERT PH protein. Comparison of the sulfate bound structure with the apo form solution structure shows structural rearrangements likely occur upon ligand binding, suggesting conformational flexibility in the ligand-binding pocket. This structural flexibility likely explains CERT PH domain’s low affinity for PtdIns(4)P, a property that is distinct from many other PH domains that bind to their phosphoinositide ligands tightly. This unique structural feature of CERT PH domain is probably tailored towards the transfer activity of CERT protein where it needs to shuttle between ER and Golgi and therefore requires short resident time on ER and Golgi membranes.
Pigmentary Macular Degeneration with Multifocal Necrotizing Encephalopathy

A previously healthy 10-year-old girl suffered sudden, binocular visual deterioration. During the next few years her neurologic and visual condition progressively worsened and she developed hypertension, seizures, ataxia, and lactic acidemia, leading to death at the age of 16 years. Bilateral optic disk pallor was followed by loss of the foveal reflex and pigmentary maculopathy, manifested as disorganization of the retinal layers, loss of ganglion cells, degeneration of the photoreceptors and nuclei, and irregular infiltration of the retina by pigment epithelial cells. The optic nerves and tracts showed central axonal loss. Bilateral, multifocal symmetric areas of cerebellar atrophy and necrosis of the neuropil and neurons in the cerebral cortex, basal ganglia, and thalamus were observed; neurons persisted in the dorsal medulla, despite neuropil degeneration.
Radial Glial Neural Progenitors Regulate Nascent Brain Vascular Network Stabilization Via Inhibition of Wnt Signaling

The cerebral cortex performs complex cognitive functions at the expense of tremendous energy consumption. Blood vessels in the brain are known to form stereotypic patterns that facilitate efficient oxygen and nutrient delivery. Yet little is known about how vessel development in the brain is normally regulated. Radial glial neural progenitors are well known for their central role in orchestrating brain neurogenesis. Here we show that, in the late embryonic cortex, radial glial neural progenitors also play a key role in brain angiogenesis, by interacting with nascent blood vessels and regulating vessel stabilization via modulation of canonical Wnt signaling. We find that ablation of radial glia results in vessel regression, concomitant with ectopic activation of Wnt signaling in endothelial cells. Direct activation of Wnt signaling also results in similar vessel regression, while attenuation of Wnt signaling substantially suppresses regression. Radial glial ablation and ectopic Wnt pathway activation leads to elevated endothelial expression of matrix metalloproteinases, while inhibition of metalloproteinase activity significantly suppresses vessel regression. These results thus reveal a previously unrecognized role of radial glial progenitors in stabilizing nascent brain vascular network and provide novel insights into the molecular cascades through which target neural tissues regulate vessel stabilization and patterning during development and throughout life.
Suppression of Sebum Secretion with 13-cis-Retinoic Acid: Effect on Individual Skin Surface Lipids and Implications for Their Anatomic Origin

The contribution of the keratinizing epidermis to the human skin surface lipid film has been difficult to ascertain because, after its release from the epidermal cells, epidermally derived lipid inevitably becomes mixed with sebum. In the present study, the sustainable rates of production of the 5 neutral lipid classes found on the skin surface (triglycerides + free fatty acids, wax esters, cholesterol, cholesterol esters, and squalene) were measured on the foreheads of acne patients before, during, and following treatment with 13-cis-retinoic acid, a drug which suppresses sebum production profoundly. Since sebum production was high in the patients before treatment and was suppressed to a few percent of the pretreatment level in some of the patients during treatment, data covering a wide range of sebum production rates were obtained. By using squalene as a measure of sebum production and plotting the rates of production of the other lipid classes vs the rate of production of squalene, it was possible through extrapolation to estimate the residual (i.e., epidermal) rate of production of each lipid class at zero sebum production. The results indicated that epidermis releases triglycerides + free fatty acids and cholesterol to the skin surface. The cholesterol esters in freshly secreted skin surface lipids appeared to be almost entirely sebaceous in origin. Measurements were also made of the percentages of cholesterol esters in lipid collected from the scalp after several days' accumulation and were compared to corresponding values for the forehead lipid. The percentages of cholesterol esters in scalp lipid tended to rise when sebum production was suppressed by the drug, rather than remaining relatively constant as occurred in the freshly secreted forehead lipid. This result indicated that epidermis may contribute to skin surface cholesterol esters, probably through skin surface esterification of epidermal cholesterol.
Electroweak constraints on heavy singlet quarks

Abstract Precision measurements of rates in processes involving electroweak gauge bosons limit contributions new physics can make to radiative corrections for such reactions. Such an analysis is used to place limits on heavy, SU (2)L singlet quarks that mix with the top quark.
Influence of density dependence on the detection of trends in unobserved life-history stages

In many species, certain life-history stages are difficult or impossible to observe directly, hampering management. Often more easily observed stages are monitored instead, but the extent to which various forms of uncertainty cloud our ability to discern trends in one critical life-history stage by observing another is poorly studied. We develop a stochastic simulation model for threatened California coho salmon Oncorhynchus kisutch to examine how well trends in one stage can be detected from observations of another. In particular, we use the model to examine the effect density dependence has on our ability to detect trends. We present a structural form for the transition between life-history stages that encompasses the common functional forms: density independence, Beverton–Holt compensatory density dependence and Ricker-type over-compensation. In small populations, such density dependence is often ignored. However, it may in fact be extremely important, for example if population decline was caused by a decrease in carrying capacity. Our results show that density dependence in any life-history transition significantly reduces the ability to detect trends in abundance; critical but inaccessible stages cannot generally be studied by monitoring more easily observed stages, especially if density dependence is present for any life-cycle transition.
Levels of chromosomally encoded Umu proteins and requirements for in vivo UmuD cleavage.

Most of the inducible mutagenesis observed in Escherichia coli after treatment with many DNA damaging agents is dependent upon the products of the umuD,C operon. RecA-mediated proteolytic processing of UmuD yields a carboxyl-terminal fragment (UmuD′) that is active for mutagenesis. Processing of UmuD is therefore a critical step in the fixation of mutations. In this paper we have analyzed the requirements for UmuD processing in vivo. Standard immuno-detection assays, coupled with a sensitive chemiluminescence detection assay, have been utilized to probe levels of chromosomally encoded Umu proteins from whole-cell E. coli extracts. We found that the derepression of additional SOS gene products, other than RecA, was not required for UmuD processing. Moreover, efficient cleavage of UmuD was observed only in the presence of elevated levels of activated RecA, suggesting that efficient processing would occur only under conditions of severe DNA damage. Detection of chromosomally encoded Umu proteins has allowed us, for the first time, to measure directly the cellular steady-state levels of these proteins under various SOS inducing conditions. UmuD was present at ∼180 copies per uninduced cell and was measured at ∼2400 copies per cell in strains that lacked a functional repressor. Induced levels of UmuC were approximately 12-fold lower than UmuD with ∼200 molecules per cell. These levels of cellular UmuC protein suggest that it functions through specific protein-DNA or protein-protein interactions, possibly as a lesion recognition protein or by interacting with DNA polymerase III.
Large-space shell-model calculations for light nuclei

An effective two-body interaction is constructed from a new Reid-like NN potential for a large no-core space consisting of six major shells and is used to generate the shell-model properties for light nuclei from A=2 to 6. For practical reasons, the model space is partially truncated for A=6. Binding energies and other physical observables are calculated and they compare favorably with experiment.
Synthesis, fluorine-18 radiolabeling, and in vitro characterization of 1-iodophenyl-N-methyl-N-fluoroalkyl-3-isoquinoline carboxamide derivatives as potential PET radioligands for imaging peripheral benzodiazepine receptor

Abstract The isoquinoline carboxamide derivative 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide (PK11195) has been shown to bind strongly and selectively to the peripheral benzodiazepine receptor (PBR) binding sites. A series of PK11195 analogues have been synthesized and biologically characterized. The affinities of the analogues for the PBR were determined using in vitro competitive binding assays with [3H]PK11195 in rat kidney mitochondrial membranes. The results showed that the 1-(2-iodophenyl)-N-methyl-N-(3-fluoropropyl)-3-isoquinoline carboxamide (9a) was the most potent compound (Ki = 0.26 nM) of this series and is an excellent lead ligand for additional studies for labeling with fluorine-18 to determine whether it possesses the desired in vivo performance in non-human primates by PET imaging. Thus, radiolabeling of 9a with fluorine-18 was developed.
Estimating Bayes Factors via Posterior Simulation with the Laplace—Metropolis Estimator

Abstract The key quantity needed for Bayesian hypothesis testing and model selection is the integrated, or marginal, likelihood of a model. We describe a way to use posterior simulation output to estimate integrated likelihoods. We describe the basic Laplace—Metropolis estimator for models without random effects. For models with random effects, we introduce the compound Laplace-Metropolis estimator. We apply this estimator to data from the World Fertility Survey and show it to give accurate results. Batching of simulation output is used to assess the uncertainty involved in using the compound Laplace-Metropolis estimator. The method allows us to test for the effects of independent variables in a random-effects model and also to test for the presence of the random effects.
Bayesian non-parametric signal extraction for Gaussian time series

Abstract We consider the problem of unobserved components in time series from a Bayesian non-parametric perspective. The identification conditions are treated as unknown and analyzed in a probabilistic framework. In particular, informative prior distributions force the spectral decomposition to be in an identifiable region. Then, the likelihood function adapts the prior decompositions to the data. A full Bayesian analysis of unobserved components will be presented for financial high frequency data. Particularly, a three component model (long-term, intra-daily and short-term) will be analyzed to emphasize the importance and the potential of this work when dealing with the Value-at-Risk analysis. A second astronomical application will show how to deal with multiple periodicities.
Trading volume around announcements of mergers and acquisitions

This study investigates the volume reaction to merger and acquisition (M&A) announcements for acquiring firms. It identifies the method of payment, target ownership, firm size and the relative size of acquisitions as important cross-sectional determinants of the volume reaction. This research is important because volume is a fundamental attribute of securities markets. Moreover, the analysis of trading volume and its determinants provides insights about which M&A attributes cause investor disagreement about the value of M&A activities.
Can resource costs of polyploidy provide an advantage to sex

The predominance of sexual reproduction despite its costs indicates that sex provides substantial benefits, which are usually thought to derive from the direct genetic consequences of recombination and syngamy. While genetic benefits of sex are certainly important, sexual and asexual individuals, lineages, or populations may also differ in physiological and life history traits that could influence outcomes of competition between sexuals and asexuals across environmental gradients. Here, we address possible phenotypic costs of a very common correlate of asexuality, polyploidy. We suggest that polyploidy could confer resource costs related to the dietary phosphorus demands of nucleic acid production; such costs could facilitate the persistence of sex in situations where asexual taxa are of higher ploidy level and phosphorus availability limits important traits like growth and reproduction. We outline predictions regarding the distribution of diploid sexual and polyploid asexual taxa across biogeochemical gradients and provide suggestions for study systems and empirical approaches for testing elements of our hypothesis.
Overview of non-intercepting beam-size monitoring with optical diffraction radiation

The initial demonstrations over the last several years of the use of optical diffraction radiation (ODR) as non-intercepting electron-beam-parameter monitors are reviewed. Developments in both far-field imaging and near-field imaging are addressed for ODR generated by a metal plane with a slit aperture, a single metal plane, and two-plane interferences. Polarization effects and sensitivities to beam size, divergence, and position will be discussed as well as a proposed path towards monitoring 10-micron beam sizes at 25 GeV.
Variable temperature Mössbauer effect spectrometer with provision for longitudinal external fields

Abstract A Mossbauer effect spectrometer design for obtaining spectra with the absorber in a longitudinal external magnetic field is described. A superconducting magnet is the source of the field. The absorber temperature can be varied between about 300°K and 1.5°K and, independently, the source temperature can be varied between 300°K and about 10°K above the absorber temperature.