cssi/SciSciGPT-SciSciNet huggingface dataset:
The Fibrous Proteins of Brain: A Primer for Gerontologists

The morphological hallmarks of the Alzheimer type of presenile dementia and of a major portion of the senile dementias are neuro-fibrillary tangles and senile plaques. The latter structures are composed of degenerating neuritic processes within a core of congophilic material, presumably amyloid (Terry and Wisniewski, 1970). Neurofibrillary tangles were originally appreciated as fine, argentophilic fibrils in the light microscope. While the neuron normally contains some such fibrils, they are greatly increased in numbers and in thickness in Alzheimer’s disease and senile dementia. Electronmicroscopic studies (Kidd, 1963; Terry, 1963) showed quite clearly that these fibrils were composed of linear structures which twisted every 80 nm and had a diameter at these nodes of 9nm and a maximum diameter between the nodes of almost 20 nm. The bulk of morphological evidence points to this pattern being due to a helical twisting of filaments around each other. These structures have been seen only in the human, only in brain and in the brain only within neurons. Nonetheless, the morphology of these twisted filaments combined with the general attention now being received by the normally occurring fibrillary elements of the brain has led to a curiosity about what relationship, if any, exists between the pathological structures and the normal microtubules, neurofilaments and micro-filaments of the nervous system. Some aspects of this question will be addressed by Dr. Iqbal later in this symposium.
Controlling the aqueous solubility of PNIPAM with hydrophobic molecular units

Abstract The effect of co-polymerization of thermo-sensitive polymers with hydrophilic or hydrophobic co-monomers on the LCST and the structure of proximal water remains a fundamental and challenging problem. Here, we employ all-atom molecular dynamics simulations to investigate the aqueous solubility of a thermo-sensitive polymer, poly(N-isopropylacrylamide) (PNIPAM), a hydrophobic polymer polystyrene (PS) and block co-polymers of PNIPAM-co-PS. The simulations of pure oligomers of PNIPAM and PS and their co-polymers are conducted below and above the LCST of PNIPAM to elucidate the effect of increase in number of PS units in PNIPAM-co-PS co-polymers on the coil-to-globule transition of PNIPAM and structure of proximal water. Our simulations suggest that while the LCST of pure PNIPAM oligomers is strongly associated with the structural changes in the proximal water molecules present near PNIPAM, inclusion of PS units disrupts the interactions between PNIPAM and water and promotes the faster dehydration of PNIPAM chains above its LCST. This phenomenon is manifested by a coil-to-globule transition in PNIPAM chains present in PNIPAM-co-PS co-polymers at much shorter times as compared to the pure PNIPAM oligomers. Our results also reveal that with increase in the number of PS units in PNIPAM-co-PS co-polymers the coil-to-globule transition is accelerated.
HIV care and treatment of American Indians/Alaska natives with diagnosed HIV infection – 27 states and the District of Columbia, 2012

The objective of this study was to measure linkage to care, retention in care, and suppressed viral load (VL) among American Indians/Alaska Natives (AIs/ANs) aged ≥13 years with diagnosed HIV infection. We used national HIV case surveillance data to measure linkage to care, defined as ≥1 CD4 or VL test ≤1 month after HIV diagnosis during 2013; retention in care, defined as ≥2 CD4 or VL tests ≥3 months apart during 2012; and suppressed VL, defined as <200 copies/mL at the most recent VL test during 2012. In 2013, 74.1% of AIs/ANs were linked to care. At year-end 2012, 46.9% of AIs/ANs were retained in care and 45.1% were virally suppressed. A lower percentage of females (41.3%), compared with males (46.5), were virally suppressed. By age group, the lowest percentage of virally suppressed AIs/ANs (37.5%) were aged 13-34 years. To improve individual health and to prevent HIV among AIs/ANs, outcomes must improve - particularly for female AIs/ANs and for AIs/ANs aged 13-34 years. Screening for HIV infection in accordance with Centers for Disease Control and Prevention's testing recommendations can lead to improvements along the continuum of HIV care.
Blue light, green light, white light, more light: treatment of neonatal jaundice.

This article reviews the current understanding of how phototherapy, the most widely used treatment of neonatal jaundice, uses light energy to pump bilirubin out of a jaundiced infant. It provides a framework for understanding the often conflicting results of clinical comparisons of various phototherapeutic regimens, and stresses the imt intensity in the overall effective.
Novel Method Measuring Intracranial Vessel Caliber Reveals Arterial Remodeling In HIV (P6.072)

Objective: Characterize vessel caliber in HIV patients with and without HAND. Background: In vivo MRI measurements of cerebrovascular caliber could offer insight into the pathology of HIV in the CNS. Postmortem studies have shown lower blood-vessel wall thickness in HIV infected individuals, indicating possible arterial remodeling. We measured the vessel caliber in HIV patients in vivo using high-resolution MRI and compared it to that from matched control subjects. Methods: T2* weighted MRI was acquired at 0.55 mm isotropic resolution on a Philips 3T scanner with 8-channel head coil in 13 subjects with HIV-associated neurocognitive disorders (HAND, mean and standard deviation of age 49±9 years, 62[percnt] male), 43 HIV without HAND (HIV, 51±8 years, 56[percnt] male) and 23 socioeconomically matched controls without HIV (Control, 44±11 years, 57[percnt] male). Cross-sectional areas of the A1 segment of anterior cerebral arteries and M1 branch of middle cerebral arteries were measured using a MATLAB program developed in house. One-way ANOVAs and two-tailed t-tests were used to assess group differences, and results are reported as mean ± standard deviation. Results: HIVs had significantly larger A1 cross-sectional areas (5.5±2.0 mm2) than Controls (4.6±1.0 mm2), and HAND also trended to have larger A1 areas (5.2±1.5 mm2) than Controls (ANOVA p<0.05). While no significant differences were seen in M1 across cohorts, men had consistently larger M1 areas than women in HIV (7.5.1±1.2 mm2 and 6.8±0.8 mm2 respectively, p<0.05) and HAND (8.0±1.3 mm2 and 6.9±1.1 mm2, p<0.05). There were no correlations between arterial caliber and age. Conclusions: HIV patients with and without HAND had larger ACA cross-sectional areas than control subjects, perhaps consistent with the reports of significantly thinner vessel walls seen in HIV patients post-mortem. The difference in vessel size between men and women in MCA shows the ability of this method to detect subtle differences in arterial caliber. Disclosure: Dr. De Alwis has nothing to disclose. Dr. Artrip has nothing to disclose. Dr. Liu has nothing to disclose. Dr. Smith has nothing to disclose. Dr. Nath has nothing to disclose. Dr. Reich has received research support from Vertex Pharmaceuticals. Dr. Nair has nothing to disclose.
Mitochondrial DNA from Podospora anserina : IV. The large ribosomal RNA gene contains two long intervening sequences.

We have examined the structure of the rRNA genes from the mitochondrial genome of Podospora anserina. Using R-loop analysis, nuclease protection experiments, and Southern blot hybridization analysis we have observed two intervening sequences (IVS) in the large rRNA gene, and none in the small rRNA gene. the IVS sequences are 1.65 kbp and 2.73 kbp long, and the larger of the two is in the position of the conserved IVS found in the mitochondrial genomes of other fungi. We have detected precursor transcripts for the large rRNA, and these data support the observation of two IVS in this gene. We also note that the large and small rRNA genes are separated by approximately 6 kbp of DNA.
Fibroblast growth factor 21 decreases after liver fat reduction via growth hormone augmentation

Abstract Objective Fibroblast growth factor 21 (FGF21) ameliorates steatohepatitis but is increased in humans with fatty liver, potentially due to compensatory mechanisms and/or FGF21 resistance. Further, animal models suggest that GH increases serum FGF21. Tesamorelin, a growth hormone releasing hormone agonist, reduces liver fat in HIV-infected individuals. The objectives of this study were to investigate changes in FGF21 during tesamorelin treatment, to elucide the interplay between FGF21, GH augmentation, and liver fat reduction in humans. Methods 50 HIV-infected men and women with increased abdominal adiposity participated in this randomized, placebo-controlled trial of tesamorelin, 2 mg vs. identical placebo daily for six months. Fasting laboratory measures, liver fat by 1 H-magnetic resonance spectroscopy, and visceral adipose tissue (VAT) by computed tomography were obtained. Euglycemic hyperinsulinemic clamp was performed in a randomly selected subset. Results At baseline, serum log 10 FGF21 was significantly associated with log 10 liver fat ( r = 0.32, p = 0.03). Log 10 FGF21 tended to decrease in the tesamorelin group compared to placebo ( p = 0.06). Among the entire cohort, reductions in FGF21 were significantly associated with reductions in liver fat (ρ = 0.41, p = 0.01), log 10 gamma glutamyl tran speptidase (GGT, r = 0.40, p = 0.009), and FIB4 index ( r = 0.37, p = 0.02). Conclusions In HIV-infected individuals, FGF21 is significantly positively associated with liver fat. FGF21 decreases in association with reductions in liver fat, GGT, and FIB4, suggesting that FGF21 is upregulated in the context of steatosis and steatohepatitis and is reduced when these conditions improve. Moreover, these data suggest that tesamorelin improves liver fat via pathways other than increasing serum FGF21. Trial registration clinicaltrials.gov NCT01263717 .
Molecular imaging of advanced thyroid cancer: iodinated radiotracers and beyond.

An important aspect of differentiated thyroid cancer (DTC) management is disease localization by imaging. Functional imaging of thyroid cancer with iodinated radiotracers has been employed for metastatic disease detection for long. More recently, 2-deoxy-2-[18F] fluoro-d-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT), a non-iodinated ubiquitous PET tracer, has been used to detect non-radioiodine (RAI) avid disease. Advances in molecular imaging have led to the development of newer tracers like 18F-TFB (18F-tetrafluoroborate) that are transported through the sodium–iodide symporter (NIS) as well as 68 Ga-DOTATATE that image the somatostatin receptors sub-type 2 expressed in medullary thyroid cancer and some DTC. In coming years, there will be focus on newer receptor targets like prostate-specific membrane antigen expression and endoradiotherapies and theranostics.
POWER AND THE ILLUSION OF TRANSPARENCY IN NEGOTIATIONS

This study examines how the illusion of transparency in negotiation differs depending on whether one is the powerful or less powerful negotiator. The illusion of transparency is the tendency for individuals to overestimate the extent to which their internal states and intentions are apparent to an outside observer. Thus, this illusion equals the difference between perceived and actual transparency. We predict that less powerful negotiators experience more perceived transparency than do powerful negotiators and that powerful negotiators exhibit greater actual transparency than do less powerful negotiators. The main hypothesis that the illusion of transparency is greater for less powerful negotiators than for powerful negotiators was supported.
Viral Membrane Proteins as Tools to Study Protein Folding, Assembly, and Transport

The endoplasmic reticulum (ER) maintains a highly specialized environment that supports rapid and efficient protein folding and assembly. Viral membrane proteins have been used as tools to understand these processes. In this paper, we will review commonly used techniques that may be employed to monitor protein folding and assembly. Such approaches can be used to characterize folding factors in the ER as well as to develop a more complete understanding of viral membrane protein biosynthesis. Such information is required to fully evaluate the effects of mutations on viral membrane protein structure and function.
Effect of organic solvents and their dielectric constants on ion selective electrode potential

The effects of mixtures of water with methanol, ethanol, acetone, dimethylsulfoxide (DMSO), andp-dioxane on the lead ion selective electrode potential have been studied. With the exception of DMSO which decreases the potential, other organic solvents stated above show an increased potential effect. Both the lead ion electrode and the silver arsenite electrode show an approximately linear decreasing relationship between the potential and the dielectric constant of organic solvents studied.
WAVE EQUATIONS AND INVERSE SOLUTIONS FOR SOFT TISSUE

Ultrasound has been used in the echo mode as a diagnostic tool for many years. The images produced by the echo mode are not qualitative and do not measure absolute tissue properties. Rather, echo-mode images display the changes in acoustic impedance. Thus, the boundaries of tissues are imaged. Such images are of value for study of anatomy and tissue morphology. Tumors are detected by their shape and not by their tissue type. Thus, classification of malignant or benign tumors is difficult by use of echo-mode imaging alone. The recently developed straight-line ultrasound transmission tomographic methods provide images which are qualitative and absolute (not relative), but have inferior resolution compared to the echo methods [Greenleaf, et al., 1978].
Introduction to Low-Energy Nuclear Physics

The No-Core Shell Model (NCSM) is a first-principles nuclear structure technique, with which one can calculate the observable properties of light nuclei
Failure to reabsorb the primary cilium induces cellular senescence

Aurora kinase A (AURKA) is necessary for proper primary cilium disassembly before mitosis. We found that depletion of caveolin-1 expression promotes primary cilia formation through the proteasomal-dependent degradation of aurora kinase A and induces premature senescence in human fibroblasts. Down-regulation of intraflagellar transport-88, a protein essential for ciliogenesis, inhibits premature senescence induced by the depletion of caveolin-1. In support of these findings, we showed that alisertib, a pharmacological inhibitor of AURKA, causes primary cilia formation and cellular senescence by irreversibly arresting cell growth. Suppression of primary cilia formation limits cellular senescence induced by alisertib. The primary cilium must be disassembled to free its centriole to form the centrosome, a necessary structure for mitotic spindle assembly and cell division. We showed that the use of the centriole to form primary cilia blocks centrosome formation and mitotic spindle assembly and prevents the completion of mitosis in cells in which cellular senescence is caused by the inhibition of AURKA. We also found that AURKA is down-regulated and primary cilia formation is enhanced when cellular senescence is promoted by other senescence-inducing stimuli, such as oxidative stress and UV light. Thus, we propose that impaired AURKA function induces premature senescence by preventing reabsorption of the primary cilium, which inhibits centrosome and mitotic spindle formation and consequently prevents the completion of mitosis. Our study causally links the inability of the cell to disassemble the primary cilium, a microtubule-based cellular organelle, to the development of premature senescence, a functionally and pathologically relevant cellular state.-Jeffries, E. P., Di Filippo, M., Galbiati, F. Failure to reabsorb the primary cilium induces cellular senescence.
Diagnosing and Predicting ENSO SSTA Development from Moored-Buoy and Scatterometer Winds

AbstractAccurate real-time knowledge of equatorial Pacific wind stress is critical for monitoring the state of the tropical Pacific Ocean and understanding sea surface temperature anomaly (SSTA) de...
Cryptococcus Species Other Than Cryptococcus neoformans and Cryptococcus gattii: Are They Clinically Significant?

Background Cryptococcus spp is a major cause of opportunistic infections in immunocompromised patients, primarily due to Cryptococcus neoformans and Cryptococcus gattii. There are occasional reports of other Cryptococcus species causing invasive human disease. However, their epidemiology and clinical significance are not fully defined. We sought to describe cases with cultures positive for Cryptococcus species other than C neoformans and C gattii. Methods A retrospective descriptive analysis of clinical and laboratory data of patients with cultures growing Cryptococcus species other than C neoformans and C gattii from November 2011 to February 2019 was performed. Three Mayo Clinic sites in Arizona, Florida, and Minnesota were included. Results From 176 cases with a culture growing Cryptococcus spp, 54 patients (30%) had a culture for Cryptococcus other than C neoformans and C gattii in the study time frame. The most common species were Cryptococcus magnus, Cryptococcus laurentii, and Cryptococcus ater. The organisms were isolated and identified in culture of bronchoalveolar lavage (11), skin (11), urine (7), oral (4), sinus (3), intraoperative soft tissue (3), sputum (2), synovial fluid (2), cerebrospinal fluid (2), and intravenous catheter (2), among others (7).Only 8 (15%) cases were considered to be potentially pathogenic, with 1 case of invasive disease. Antifungal treatment was fluconazole, itraconazole, and griseofulvin, for a mean systemic antifungal duration of 42 days. Conclusions This large series of patients with Cryptococcus spp other than C neoformans and C gattii suggests that these species rarely cause clinically significant infection in humans. Only 1 case of invasive disease was found.
The Influence of Retail Return Policies on Brand Image: An Abstract

U.S. retailers lose in excess of $350 billion in sales per year due to returns (Appriss 2017). The area of product returns continues to be an under-researched area, despite its significance to manufacturers and retailers (Yon Seo et al. 2015). To date, a large amount of the research on product returns seeks to identify personality traits of customers, which can be used to pinpoint and predict who will return products (e.g., age; Daunt and Harris 2012), or to provide evidence that strategically increasing the stringency of return policies will reduce returns (e.g., Petersen and Kumar 2010; Powers and Jack 2013). In contrast, the current research investigates whether a strict return policy is always in the best interest of the retailer. We investigate whether a lenient return policy can have a positive long-term impact on retailers by favorably influencing brand image and other related brand outcomes.
Reflections on elimination theory

My lecture will survey developments in elimination theory from Newton and Bezout up to modern times. I will discuss the dominance of elimination theory in the 19th century and the challenges it faced in the 20th century with the rise of abstract algebraic geometry. I will also mention the role of the ISSAC community and some personal history.
A Profile of Unaccompanied Children in Maryland and Virginia

Between 2014 and 2016, 18,858 unaccompanied children resettled in Maryland and Virginia from Guatemala, Honduras, and El Salvador. This report examines a subset of these youth who receive post-release services through Lutheran Immigration and Refugee Service. By building a profile of these youth, the report seeks to better understand the characteristics and experiences of unaccompanied children in the region in an aim to ensure the alignment of needs to services provided.
Prediction of Stress-Strain Behavior of Thermally Cycled SAC305 Solder Joints by Finite Element Modeling and Nanoindentation Characterization

Plastic ball grid array (PBGA) packages are one of the widely used electronic packages in semiconductor industry. In PBGA packages, solder joint is the most vulnerable component due to continuous exposure of cycling temperatures in real applications. In our previous study, it was found that cyclic temperature causes the solder joints to evolve their mechanical properties. The continuous shear fatigue on solder joints due to CTE mismatch between die and PCB material causes damage on the solder material which eventually leads to crack propagation and failure. Hence, it is important to understand the change in stress-strain behavior in real solder joints and to identify the critical region of failure during this temperature cycling phenomena. In our previous paper, we have analyzed evolution of mechanical behavior of SAC305 solder joints as a function of cycling using nanoindentation technique.In this study, we have used FEA modeling technique to understand change in stress-strain behavior of as reflowed and thermally cycled solder joints and identify critical failure location under shear loading. A simplified three dimensional model of solder joint was generated and simulated using ANSYS software. Most of the prior studies predicted the stress-strain behavior of solder joints using viscoplastic model based on bulk solder material characterization and not on real joints. In this study, we have utilized nanoindentation technique to extract material properties of SAC305 solder joints to incorporate into ANSYS software. At first, test specimen were prepared by cross sectioning a PBGA package to reveal single grain SAC305 solder joints by surface polishing to facilitate SEM imaging and nanoindentation testing. After preparation, the package sample were thermally cycled from T = -40 to 125 oC in an environmental chamber. At various points in the cycling (e.g. after 0, 50, 100, 250, 500,750 and 1000 cycles), the package was taken out from the thermal cycling chamber. Nanoindentation testing was then performed at room temperature (25 oC) on above single grain solder joints to obtain equivalent mechanical behavior. Elastic-viscoplastic material properties were extracted as a function of no. of thermal cycles which was used for FEA analysis.
Playing with symmetry with neural networks

Finding the optimum design of a complex auction is a challenging and important economic problem. Multi-agent deep learning can help find equilibria by making use of inherent symmetries in bidding strategies.
Homoeologous chromosome exchange explains the creation of a QTL affecting soil-borne pathogen resistance in tobacco.

Crop plant partial resistance to plant pathogens controlled by quantitative trait loci (QTL) is desirable in cultivar development programmes because of its increased durability. Mechanisms underlying such resistance are difficult to study. We performed RNA-seq analyses for tobacco (Nicotiana tabacum) nearly isogenic lines (NILs) with and without favourable allele(s) at Phn7.1, a major QTL influencing partial resistance to the soil-borne pathogens Phytophthora nicotianae and Ralstonia solanacearum. Based upon combined analyses of transcriptome-based sequence variation and gene expression profiles, we concluded that allelic variability at the Phn7.1 locus was likely generated from homoeologous exchange, which led to deletion of low-expressing members of the SAR8.2 gene family and duplication of high-expressing SAR8.2 genes from a different subgenome of allotetraploid tobacco. The high expression of endogenous Phn7.1-associated SAR8.2 genes was correlated with observed resistance to P. nicotianae. Our findings suggest a role for genomic rearrangements in the generation of favourable genetic variability affecting resistance to pathogens in plants.
Trazodone for erectile dysfunction: A systematic review and meta-analysis

Evidence-based medicine is an important way of allowing the reader to judge clearly whether a treatment has a place in a particular condition, and to see what faults were present in the various trials of its efficacy. It is often rather unsettling to read in a meta-analysis or in a systematic literature review how poorly constructed many trials are. The authors from Minneapolis have carried out such a study into the use of trazodone in male erectile dysfunction. They draw attention to the poor quality of many of the trials and give their reasons for this observation. They suggest that trazodone may be helpful in men with this condition, possibly at higher doses and in men with psychogenic erectile dysfunction.
Problem solving environment approach to integrating diverse biological data sources

Scientists face an ever-increasing challenge in investigating biological systems with high throughput experimental methods such as mass spectrometry and gene arrays because of the scale and complexity of the data and the need to integrate results broadly with heterogeneous other types of information. Many analyses require merging the experimental results with datasets returned from public databases, such as those hosted by the National Center for Biotechnology (NCBI), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein interaction databases such as the Biomolecular Interaction Network Database (BIND). Because data sources such as these are constantly evolving the researcher is faced with hurdles to manually gather, integrate and manage the data into cohesive datasets. To overcome these technical problems, we have been building a three-tier software system that includes a client-side graphical user interface for rich interaction with the data, an application server that hides the messy technical details of data collection, integration, and management tasks from the researcher, and a flexible database schema that efficiently manages mixed data source content. The software is being developed using Java for portability and Open Source technology so that it can one day be freely distributed. This problem-solving environment is called the Computational Cell Environment (CCE) and is designed to provide scalable and agile connectivity to diverse data stores and eventually provide data retrieval, management, and analysis through all aspects of biological study.
A method for narrowband interference mitigation in OFDM by minimizing spectral leakage

Current generation narrowband power-line communication systems are OFDM based. They are especially susceptible to narrowband interference (NBI) which is generated by switching power supplies and legacy communication systems. In this paper we propose a novel method for mitigating the effect of NBI. The method exploits a well-known characteristic of NBI spectral leakage in that it is frequency dependent. The method involves intentionally introducing inter-carrier interference at the receiver in a controlled manner in order to mitigate the NBI effect with low computational complexity. A simple NBI frequency estimator is also proposed. The combined receiver solution is shown to be within 0.5 dB of the AWGN performance bound for the current G3-FCC standard in the presence of a single NBI.
An electron microscopic analysis of hippocampal neurons developing in culture: Early stages in the emergence of polarity

In culture, hippocampal neurons initially establish several short, minor processes. The initial step in the emergence of polarity is marked by the rapid and selective growth of one of these processes, which becomes the axon. Subsequently the remaining processes become dendrites. We examined the ultrastructure of hippocampal neurons before and after the emergence of the axon. The minor processes in cells that had not yet formed axons were somewhat variable in appearance, but we found no ultrastructural feature that indicated which minor process might become the axon. The emergence of the axon was marked by several changes in its ultrastructure. The axon contained a sevenfold lower density of polyribosomes than the minor processes. In addition, axonal growth cones contained a pronounced concentration of membranous elements that resembled endoplasmic reticulum, elements that were rare in the growth cones of minor processes. Axons and minor processes did not differ in microtubule density. In order to gauge how rapidly these ultrastructural changes occur, we examined cells with short axons that, from their length, were estimated to have emerged only hours earlier. The preferential exclusion of polyribosomes from the axon and the concentration of reticular membrane in the axonal growth cone were already evident in such cells. These observations demonstrate that exclusion of ribosomes from the axon occurs early in development, about as soon as the axon can be identified. In contrast, previous work has shown that the differences in microtubule polarity orientation that distinguish mature axons and dendrites, and that have been proposed to account for the selective segregation of some constituents in neurons, first appear at a later stage of development (Baas et al., 1989). These observations also demonstrate that the accumulation of reticular membrane elements in growth cones, which has been noted previously, occurs preferentially in axonal growth cones and is closely correlated in time with the initial specification of the axon. The selective concentration of these elements in axonal growth cones could be associated with the uniquely rapid rate of axonal growth.
Civil War and Life Chances A Multinational Study

Civil war adversely affects life chances (i.e. economic well-being, food production and education) that are key to social and economic development; civil war and these life chances all, potentially, affect the most basic life chance — mortality. Results show that civil war worsens child mortality despite controls for other life chances. In contrast, civil war accounts for much of the impact of other life chances on child mortality. Information comes from 175 countries from 1985 through 1998. Given the broad and persistent impact of civil war, future research concerned with social and economic development and, ultimately, the life chances of the masses should consider civil war as a factor in their theories and analyses.
Dissociation of N2 Gas-induced Monomeric Ribosomes and Functioning of the Derived Subunits in Protein Synthesis in Pea

The dissociation of N(2) gas-induced monomeric ribosomes from the pea root was studied by varying the concentration of KCl (or NH(4)Cl) and MgCl(2) in the presence of dithiothreitol. These monoribosomes were shown to dissociate completely into subunits at 0.5m KCl or NH(4)Cl in the presence of 5 mm MgCl(2). The 40S subunits were more susceptible to structural change in KCl than were the 60S subunits. On the other hand, the 60S subunits appeared to be more labile to NH(4)Cl.The activity of the subunits relative to aminoacyl-tRNA binding and peptide bond formation was investigated using subunits derived from 0.5 m KCl (or NH(4)Cl) in the absence and presence of 5 mm MgCl(2). The 40S subunits were active in aminoacyl-tRNA binding only when dissociated in the presence of MgCl(2). The 40S and 60S subunits combined in the presence of poly U were active in incorporation of (14)C-phenylalanine from (14)C-phenylalanyl-tRNA only when dissociation was achieved in the presence of 5 mm MgCl(2). The KCl-dissociated subunits were much more active in protein synthesis than NH(4)Cl-dissociated subunits.
Electromagnetic beam propagation through the atmosphere: Effects of source coherence and turbulence on the degree of polarization

The effects of atmospheric turbulence on the degree of polarization (DOP) of a partially coherent electromagnetic Gaussian Schell-model beam are discussed. The analysis is based on unified theory of coherence and polarization and on the extended Huygens-Fresnel principle. Intermediate and far-zone behavior of the DOP are discussed.
Getting into the habit: using historical science to understand race in contemporary schools

Most historical analyses of the scientific study of race focus on the surface level physical features of differing bodies. They fail to consider the scientific and popular accounts of racialized bodies as engaged in routine activity, thereby overlooking corporeal habits as the key historical tenet of the construction of scientific racial categorization. This paper traces the study of race via habits through modern science and attempts to reconcile this approach to understanding race with contemporary popular notions that uphold the lived experience of race and conflicting genetic accounts that debunk racial distinction. Moreover, the paper explores habits of discerning and living race that are cultivated in schools and through popular culture. Offering a pragmatist and poststructuralist theoretical analysis of habit as socially and biologically co‐constituted, this paper argues that habits should overtly occupy the minds of scientists, social constructionists, and teachers as they enact and respond to rac...
Evolution of Charged Evaporating Black Holes

The evaporative evolution of charged nonrotating black holes is studied by numerically integrating a set of coupled differential equations describing the charge and mass as functions of time. We find that large charged black holes will evolve through a region (in the black-hole configuration space) of positive specific heat, undergoing two phase transitions as they evaporate. The region is approximately bounded by $\frac{3}{4}l{(\frac{Q}{M})}^{2}l1$ and $Mg2.03\ifmmode\times\else\texttimes\fi{}{10}^{7}{M}_{\ensuremath{\bigodot}}$. Unlike rotating black holes (which always evolve toward the Schwarzschild limit), sufficiently large charged black holes will initially evolve toward the extreme Reissner-Nordstr\"om limit; their lifetime may be many orders of magnitude larger than the lifetime of a Schwarzschild black hole with the same initial mass.
Arrows of time and the beginning of the universe

I examine two cosmological scenarios in which the thermodynamic arrow of time points in opposite directions in the asymptotic past and future. The first scenario, suggested by Aguirre and Gratton, assumes that the two asymptotic regions are separated by a de Sitter-like bounce, with low-entropy boundary conditions imposed at the bounce. Such boundary conditions naturally arise from quantum cosmology with Hartle-Hawking wave function of the universe. The bounce hypersurface breaks de Sitter invariance and represents the beginning of the universe in this model. The second scenario, proposed by Carroll and Chen, assumes some generic initial conditions on an infinite spacelike Cauchy surface. They argue that the resulting spacetime will be nonsingular, apart from black holes that could be formed as the initial data is evolved, and will exhibit eternal inflation in both time directions. Here I show, assuming the null convergence condition, that the Cauchy surface in a nonsingular (apart from black holes) universe with two asymptotically inflating regions must necessarily be compact. I also argue that the size of the universe at the bounce between the two asymptotic regions cannot much exceed the de Sitter horizon. The spacetime structure is then very similar to that in the Aguirre-Gratton scenario and does require special boundary conditions at the bounce. If cosmological singularities are allowed, then an infinite Cauchy surface with ``random'' initial data will generally produce inflating regions in both time directions. These regions, however, will be surrounded by singularities and will have singularities in their past or future.
Inhibition of α-farnesene biosynthesis and its oxidation in the peel tissue of “d'Anjou” pears by low-O2/elevated CO2 atmospheres

Abstract “d'Anjou” pear fruit ( Pyrus communis , L.) harvested at optimum maturity with flesh firmness of 63±1 Newton, were stored at −1°C (±0.5°C) in a controlled atmospheric (CA) environment with 1.5–2.0% O 2 for 20 days. Subsequently, the fruits were stored at 0.5% O 2 for another 73 days. The concentration of CO 2 in the CA room began at 0.03% and accumulated gradually to 2.7% after 93 days of storage. The hyper-low O 2 and the elevated CO 2 stress inhibited the accumulation of α-farnesene and conjugated trienes in the peel tissue of “d'Anjou” fruit. This inhibiting effect was persistant but reversible after fruit had been returned to air storage at −1°C. All fruit subjected to this stress were absolutely free from superficial scald disorder during 9 weeks of holding in air at −1°C plus 7 days ripening in air at 20°C. This treatment may be a potential substitute for the current chemical (i.e., ethoxyquin) treatment for the control of superficial scald of “d'Anjou” pears. However, the elevated CO 2 levels induced pithy brown core (PBC) disorder, and experiments are underway to control CO 2 in order to minimise both superficial scald and PBC.
Terahertz wave generation in nitrogen gas using shaped optical pulses

We demonstrate the control of terahertz (THz) wave generation in nitrogen gas using shaped optical pulses with a spatial light modulator (SLM). We employ a genetic optimization algorithm to optimize the optical excitation pulses for the THz wave generation. A comparison of the optimization processes using THz power and second harmonics intensity as fitness functions is given. We also show that THz pulse trains with variable separation of pulses can be generated by using a series of periodic rectangular optical phases in Fourier space.
X-ray photoelectron study of Al-Mn alloys

Abstract X-ray photoelectron Spectroscopy (XPS) has been employed to study the electronic structure of orthorhombic Al6Mn, Al-26 wt% Mn and Al-28 wt% Mn (icosahedral phase), and Al-35 wt% Mn (decagonal phase). From the plasmons associated with Al 2s peak the valence electron density at the Al site was calculated. An increase in the electron density was found in the quasicrystals as compared with the orthorhombic or pure Al. The total energy shift in the Al 2p and Mn 2p 3 2 peaks after relaxation energy subtraction showed the existence of sp-d hybridization in the Mn conduction band of the quasicrystals. We have also shown that the FWHM of the Al 2p peaks obtained by XPS serves as a measure of the interatomic distances and mass-density. The conclusions correlate very well with the reported experimental data and theoretical calculations.
High speed photography of airborne atmospheric particles

Abstract Atmospheric particles ≳10μ in diameter have been successfully photographed in situ using cameras with microsecond-duration flash lamps. Several such cameras developed and used in the past are discussed in this article. A bright-field camera for photographing precipitation particles, and a light-weight portable dark-field camera for photographing cloud particles have been developed at this laboratory. Several representative photographs are presented to demonstrate these cameras' imaging properties and to illustrate their use. The cameras have been used successfully to photograph particles at ground level. Mechanical motion compensation will be required at aircraft speeds if nonstreaked images are to be produced.
Isolation and characterization of Tn7 transposase gain-of-function mutants: a model for transposase activation.

Tn7 transposition has been hypothesized to require a heteromeric transposase formed by two Tn7-encoded proteins, TnsA and TnsB, and accessory proteins that activate the transposase when they are associated with an appropriate target DNA. This study investigates the mechanism of Tn7 transposase activation by isolation and analysis of transposase gain-of-function mutants that are active in the absence of these accessory proteins. This work shows directly that TnsA and TnsB are essential and sufficient components of the Tn7 transposase and also provides insight into the signals that activate the transposase. We also describe a protein–protein interaction between TnsA and TnsC, a regulatory accessory protein, that is likely to be critical for transposase activation.
Comparison of laser-induced and planar laser-induced fluorescence measurements of nitric oxide in a high-pressure, swirl-stabilized, spray flame

We report spatially resolved linear laser-induced fluorescence (LIF) and planar laser-induced fluorescence (PLIF) measurements of nitric oxide (NO) in a pre-heated, high-pressure (4.27 atm), lean direct-injection (LDI) spray flame. The feasibility of using PLIF in lieu of LIF is assessed with respect to measuring NO concentrations in high-pressure LDI spray flames. NO is excited via the resonant Q2(26.5) transition of the γ(0,0) band while a non-resonant wavelength is employed to subtract background interferences. LIF detection is performed in a 2-nm region centered on the γ(0,1) band. PLIF detection is performed in a 68-nm window that captures fluorescence from several vibrational bands. An in situ NO doping scheme for fluorescence calibration is successfully employed to quantify the LIF signals. However, a similar calibration scheme for the reduction of PLIF images to quantitative field measurements is plagued by the laser-excited background. Excitation scans and calibration comparisons have been performed to assess the background contribution for PLIF detection. Quantitative radial NO profiles measured by LIF are presented and analyzed so as to correct the PLIF measurements to within the accuracy bars of the LIF measurements via a single-point scaling of the PLIF image.
Changes in maps of language function and the integrity of the arcuate fasciculus after therapy for chronic aphasia

A patient with chronic aphasia secondary to unilateral stroke in the left hemisphere underwent language testing, diffusion tensor imaging (DTI), and functional imaging using magnetoencephalography (MEG) at four time points: 3 weeks prior to, immediately prior to, immediately after, and 3 months after Constraint Induced Language Therapy (CILT). Performance on language tests involving visual naming and repetition of spoken sentences improved between the immediately prior to and immediately after CILT testing sessions, but not between the pre-CILT sessions. MEG activation in putative pre-morbid language areas of the left hemisphere and homotopic areas of the right hemisphere increased immediately after therapy, as did integrity within the arcuate fasciculus bilaterally. These changes were not evident between the two pre-CILT sessions. While some of these functional, neurophysiological and structural changes had regressed 3 months after therapy, all remained at or above baseline levels. Results provide evidence for an association between improvement in functional status and the increased integrity within a white matter tract known to be involved in language function and its contralateral homologue, as well as increased neurophysiological activity in areas that have the potential to subserve language function bilaterally.
Estradiol enhances behavioral sensitization to cocaine and amphetamine-stimulated striatal [3H]dopamine release.

Locomotor activity and stereotypy induced by cocaine is increased or ‘sensititized’ after repeated cocaine administration. This behavioral sensitization may be mediated by a persistent increase in dopamine (DA) transmission in mesolimbic and nigrostriatal pathways. Since the female estrous cycle and ovarian steroid hormones appear to affect both cocaine sensitization and DA transmission, studies were undertaken to determine the effects of ovarian steroids on sensitization of the behavioral responses to repeated cocaine injections and any concomitant effects on striatal DA release. Young female adult rats were ovariectomized and 2 weeks later were implanted with chronic release forms of estradiol (E), progesterone (P), both (EP) or vehicle (V). Locomotor and stereotypic behavior were rated after an initial injection of either saline or cocaine (10 mg/kg, i.p.) and after the 8th daily injection of saline or cocaine. A significant increase in both locomotor and stereotypic behaviors was seen after first cocaine injection relative to saline-injected animals and this response was not affected by steroid treatment. Repeated injections of cocaine caused sensitization of the initial behavioral response to cocaine (i.e. an increase in stereotypic and locomotor behavior) and the degree of cocaine sensitization was greatest in group E. Steroid treatment did not affect behavior in saline-treated rats. When striatal [3H]DA release was measured in vitro 1 or 7 days after the last injection, amphetamine-stimulated release was greater in vehicle-treated rats 7 days after cocaine injections but not 1 day after injections. In contrast, release was enhanced in group E both 1 and 7 days after cocaine. Combined EP treatment or P treatment alone did not enhance either behavioral sensitization of cocaine or amphetamine-stimulated release. Collectively these data indicate that E enhances both behavioral sensitization to cocaine and amphetamine-stimulated striatal DA release supporting the hypothesis that DA release may be E-modulated, neurochemical substrate of the behavioral effects of repeated cocaine exposure.
Silicon detector upgrades for the Tevatron run 2

The current silicon devices being used by the D0 and CDF collaborations for the Tevatron Run 2a, which is expected to end in 2005 after accumulating about 2 fb{sup -1} of data, will need to be replaced due to radiation damage for the following data collection period designated as Run 2b. We will discuss these silicon replacement plans, the more uniform design of the detectors between D0 and CDF, and the current status of their fabrication.
Relation of Students' Behavioral Style to Estimated and Measured Intelligence:

Two junior high school English teachers estimated the intelligence and behavioral style of their 87 seventh-grade students. Teachers' estimates of pupils' intelligence correlated highly (.94) with measured intelligence. The correlation between behavioral style and measured intelligence was also high and positive (.62). The results were discrepant with those of previous research. Alternative explanations of the differences are discussed. It is concluded that the relation between behavioral style and measured intelligence is a result of a developmental interaction between the child's temperamental characteristics and the environment.
Lab management: insights for the new investigator

A well functioning lab is a productive lab. Here the guiding principles of good lab management are discussed.
Alternative nucleophilic substrates for the endonuclease activities of human immunodeficiency virus type 1 integrase

Retroviral integrase can use water or some small alcohols as the attacking nucleophile to nick DNA. To characterize the range of compounds that human immunodeficiency virus type 1 integrase can accommodate for its endonuclease activities, we tested 45 potential electron donors (having varied size and number or spacing of nucleophilic groups) as substrates during site-specific nicking at viral DNA ends and during nonspecific nicking reactions. We found that integrase used 22 of the 45 compounds to nick DNA, but not all active compounds were used for both activities. In particular, 13 compounds were used for site-specific and nonspecific nicking, 5 only for site-specific nicking, and 4 only for nonspecific nicking; 23 other compounds were not used for either activity. Thus, integrase can accommodate a large number of nucleophilic substrates but has selective requirements for its different activities, underscoring its dynamic properties and providing new information for modeling and understanding integrase.
The growth of Chinese minority populations.

The 55 recognized minority races in PRChina have a total population of 91.2 million. These peoples are distributed widely in two–thirds of China's territories.