cssi/SciSciGPT-SciSciNet huggingface dataset:
Edge leakage control in platinum-silicide Schottky-barrier diodes used for infrared detection

Platinum silicide (PtSi) on p-silicon Schottky-barrier focal plane arrays (FPAs) are strong candidates for infrared (IR) detection up to a wavelength of about 5 mu m. However, an inherently low quantum efficiency (about 1% at 4 mu m) makes it important to maximize the fill factor or the area of the array that is IR-sensitive. Current designs use an n/sup -/ guard ring around the PtSi diodes to suppress edge leakage. This is effective, but the guard-ring overlap can significantly reduce the sensitive area of the diode. An aluminium plate that is already used as a photon reflector above the diode in current designs can be positively biased as a field plate to create a surface depletion layer around the diode periphery. This produces leakage current suppression equivalent to the guard ring without giving up IR-sensitive diode area. >
A prototype flexible microelectrode array for implant-prosthesis applications

This paper describes techniques for the fabrication of flexible microelectrodes for recording and stimulation within the human body. The intention of the effort was to develop a prototype microelectrode array for selective electrical stimulation of the cochlear nerve in cases of profound sensory deafness. The prototype array is formed on both sides of a thin-film plastic insulating substrate† and consists of platinum conductor-elements, 0·3 μm thick and 12·7 μm wide, terminating at electrode surfaces, 250 μm wide. Metallisation of the substrate is accomplished by sputtering, and the electrode patterns are defined by photolithographic-etching techniques. Insulation of the array is achieved by dip coating in Silastic. Short term (nonstimulated) animal-tolerance studies indicate that the electrodes are biologically inert. Long-term implant studies are currently in progress, and experiments are planned to determine tissue-reaction and electrolytic-dissolution effects due to prolonged electrical stimulation. Microelectrodes using the fabrication techniques described can be applied, in practically any geometry desired, to the development of functional sensory and motor prostheses. Cet article decrit des techniques de fabrication de microelectrodes flexibles servant a l'enregistrement et a la stimulation a l'interieur du corps humain. Ces travaux avaient pour but de developper le prototype d'un systeme de microelectrode pour la stimulation electrique selective du nerf cochleaire dans les cas de sourdesse sensorielle profonde. Le systeme prototype est forme de part et d'autre d'un film plastique fin d'une substance isolante (Mylar, Teflon ou Parylene) et consiste d'un element conducteur en platine de 0,3 μm d'epaisseur et de 12,7 μm de largeur, se terminant aux surfaces d'electrodes de 250 μm de largeur. La metallisation de la substance se fait par crepitement et es traces de l'electrode sont accomplis par des techniques de gravure photolithographique. L'islolement du systeme se fait par plongee dans un bain de Silastique. Des etudes de tolerance a court terme sur animaux (non stimules) ont indique que l'electrode est biologiquement inerte. Des etudes d'implantation a long terme sont en course, les experiences ont pour intention de determiner les reactions des tissus aux effets de dissolution electrolytique causes par une stimulation electrique prolongee. Les microelectrodes confectionnees d'apres les techniques decrites, peuvent etre appliquees selon pratiquement n'importe quelle geometrie desirees, au developpement de protheses motrices et sensorielles fonctionnelles.
Splicing-dependent and -independent modes of assembly for intron-encoded box C/D snoRNPs in mammalian cells

In mammalian cells, all small nucleolar RNAs (snoRNAs) that guide rRNA modification are encoded within the introns of host genes. An optimal position about 70 nts upstream of the 3' splice site of the host intron is critical for efficient expression of box C/D snoRNAs in vivo, suggesting synergy with splicing. Here, we have used a coupled in vitro splicing-snoRNA processing system to demonstrate that assembly of box C/D snoRNP proteins is the step affected by snoRNA location, and that active splicing is essential for snoRNP assembly. Splicing blockage experiments further reveal that snoRNP proteins bind specifically at the spliceosomal C1 complex stage. In contrast, splicing-independent snoRNP assembly can occur in vitro on snoRNAs that possess stable external stems. In vivo analyses confirm that a stable stem can compensate for the unusual position of those few box C/D snoRNAs located far from the 3' splice site of their host intron.
PROTECTION BY MULTIPLE ANTIOXIDANTS AGAINST LIPID PEROXIDATION IN RAT LIVER HOMOGENATE

The purpose of this study was to test the hypothesis that multiple antioxygenic nutrients provide increased protection against lipid peroxidative damage to rat liver. Rats were fed diets (i) deficient in vitamin E and selenium (Diet 1), (ii) supplemented with vitamin E and selenium (Diet 2), (iii) supplemented with (ii) and in addition trolox C,N-acetylcysteine, coenzyme Q0, and (+)-catechin (Diet 3), or (iv) supplemented with (iii) and in addition β-carotene, ascorbic acid palmitate, canthaxanthin, and coenzyme Q10 (Diet 4). Liver homogenates were obtained from three rats fed each of the diets for six weeks and were incubated at 37°C up to two hours with and without exogenous tertiary-butyl hydroperoxide (TBHP) or Cu2+. Lipid peroxidation was determined by measurement of thiobarbituric acid substances. Diets 2 and 3 significantly protected againstin vivo hepatic lipid peroxidation, and this protection was augmented by Diet 4. Diets 2, 3, and 4 were protective against mild oxidation induced by TBHP or Cu2+. During incubations with exogenous TBHP and Cu2+, there were only small differences between diets supplemented with antioxidants in inhibition of lipid peroxidation, indicating that diets supplemented with vitamin E and selenium (Diet 2) may have provided the maximal protection for liver. The possible mechanisms of protection provided by multiple antioxidants in diets were discussed. Protection by multiple antioxidants against lipid peroxidation may translate to prevention of peroxidative damage to human tissue, a factor in human disease.
We can do better: improving perinatal health in America.

Abstract The United States spends more on perinatal healthcare than any other nation, yet it consistently ranks near the bottom on most standard measures of perinatal health. This article examines how we can do better, based on the life course perspective and the ecological model. Collectively, these paradigms suggest the need for an expanded approach to improving perinatal health in America, one that emphasizes not only risk reduction during pregnancy but also health promotion and optimization across the life course. The approach needs to be both clinical and population based, addressing individual factors as well as social determinants. This article concludes with recommendations for increasing healthcare access, improving healthcare quality, investing in wellness, strengthening families and communities, and supporting research in perinatal health.
Abundance and distribution of ichthyoplankton in Narragansett Bay, Rhode Island, 1989–1990

An ichthyoplankton survey (18 stations in seven sampling sectors) was conducted in Narragansett Bay in 1990 to provide information on abundance, distribution, and seasonal occurrence of eggs and larvae of estuarine fishes, including seasonal migrants. An additional goal was to examine changes in species composition, abundance, and distribution occurring since the last baywide survey in 1972–73. The taxonomic composition of eggs and larvae in 1990 (41 species in 25 families from 684 plankton samples) and in 1972–73 (43 species in 28 families from 6900 samples) was similar. Maximum abundance of fish eggs occurred in June and larvae in July, minimum abundance in September to February. Species diversity was greatest in May–July and lowest during January in both surveys. However, egg and larval densities in 1990 were considerably lower than in 1972–73. Bay anchovy, tautog, and cunner accounted for 86% of the eggs and 87% of the larvae in the bay in 1990. These three species accounted for only 55% of the eggs and 51% of the larvae in 1972–73, with menhaden accounting for another 18% of the eggs and 34% of the larvae. Searobins, scup, and butterfish eggs were common in 1973 (19%) but rare in 1990 (2%). Ichthyoplankton abundance for several of the most abundant species was significantly lower (p<0.05) in the Providence River, upper bay, and Greenwich Bay in 1990 than in 1972–73. Density of fish eggs and larvae in the lower portions of the bay was lower in 1990 for some species but not others. Distribution data suggested a general down-bay shift in density in 1990. *** DIRECT SUPPORT *** A01BY085 00015
Chaperoned Protein Disaggregation—The ClpB Ring Uses Its Central Channel

In this issue of Cell, Weibezahn et al. (2004) exploit a clever manipulation of the Hsp100 ring chaperone, ClpB, to gain some mechanistic and physiologic understanding of the action of this chaperone in mediating ATP-dependent disaggregation of protein aggregates that accumulate in the bacterial cytoplasm under severe heat shock conditions.
“A lot of sacrifices:” Work-family spillover and the food choice coping strategies of low wage employed parents

Integrating their work and family lives is an everyday challenge for employed parents. Competing demands for parents' time and energy may contribute to fewer meals prepared or eaten at home and poorer nutritional quality of meals. Thus, work-family spillover (feelings, attitudes, and behaviors carried over from one role to another) is a phenomenon with implications for nutrition and health. The aim of this theory-guided constructivist research was to understand how low-wage employed parents' experiences of work-family spillover affected their food choice coping strategies. Participants were 69 black, white and Latino mothers and fathers in a Northeastern US city. We explored participants' understandings of family and work roles, spillover, and food choice strategies using open-ended qualitative interviews. Data analysis was based on the constant comparative method. These parents described affective, evaluative, and behavioral instances of work-family spillover and role overload as normative parts of everyday life and dominant influences on their food choices. They used food choice coping strategies to: (1) manage feelings of stress and fatigue, (2) reduce the time and effort for meals, (3) redefine meanings and reduce expectations for food and eating, and (4) set priorities and trade off food and eating against other family needs. Only a few parents used adaptive strategies that changed work or family conditions to reduce the experience of conflict. Most coping strategies were aimed at managing feelings and redefining meanings, and were inadequate for reducing the everyday hardships from spillover and role overload. Some coping strategies exacerbated feelings of stress. These findings have implications for family nutrition, food expenditures, nutritional self-efficacy, social connections, food assistance policy, and work place strategies.
The role of cholesterol in prostate cancer

Recent epidemiological and preclinical studies have shown that the ­steroidal lipid cholesterol is a clinically relevant therapeutic target in prostate cancer. This review summarizes the findings from human studies, as well as from animal models and cell biology approaches, which suggest that high circulating cholesterol can increase the risk of aggressive prostate cancer, while pharmacological cholesterol lowering may be protective against incident or advanced disease. A variety of molecular processes are described that have been implicated experimentally in this protective scenario or are otherwise plausibly connected. There is now sufficient experimental and observational evidence in humans to prospectively apply cholesterol-­targeting strategies in selected patients to inhibit prostate cancer progression to the metastatic form of the disease.
Hominid femoral neck length

Human femoral neck length has a positive allometric or isometric relationship with total femoral length as shown by the reduced major axis slope based on logarithmic regression. The relatively long femoral neck lengths of Australopithecus cannot be explained solely as a consequence of small body size (contra Wolpoff, '78).
Effect of Boron on the Rooting of Clematis Cuttings

BORON has been observed to stimulate the rooting of large-flowered hybrid clematis cuttings. In two studies recently carried out, increased percentages of cuttings rooted and the rooting process was accelerated by boron when it was used in combination with the root-initiating hormone, indole butyric acid.
How Middle Schoolers Draw Engineers and Scientists

The perceptions young students have of engineers and scientists are often populated with misconceptions and stereotypes. Although the perceptions that young people have of engineers and of scientists have been investigated separately, they have not been systematically compared. The research reported in this paper explores the question “How are student perceptions of engineers and scientists similar and how are they different?” Approximately 1,600 middle school students from urban and suburban schools in the southeastern United States were asked to draw either an engineer or a scientist at work. Drawings included space for the students to explain what their person was doing in the picture. A checklist to code the drawings was developed and used by two raters. This paper discusses similarities and differences in middle school perceptions of scientists and engineers. Results reveal that the students involved in this study frequently perceive scientists as working indoors conducting experiments. A large fraction of the students have no perception of engineering. Others frequently perceive engineers as working outdoors in manual labor. The findings have implications for the development and implementation of engineering outreach efforts.
Direct Observation of Ultrafast Electron Injection from Coumarin 343 to TiO2 Nanoparticles by Femtosecond Infrared Spectroscopy

Transient infrared (IR) absorption of injected electrons in colloidal TiO2 nanoparticles in the 1900−2000 cm-1 region are measured by femtosecond IR spectroscopy. The direct detection of electrons in the nanoparticles with subpicosecond time resolution provides a new approach to study ultrafast interfacial electron transfer between semiconductor nanoparticles and molecular adsorbates. The dynamics of electron injection from sensitizers to nanoparticles and the subsequent back-transfer and relaxation dynamics of the injected electrons correspond to the rise and decay of the transient IR signal of injected electrons. Using this technique, the injection time for coumarin 343 sensitized TiO2 nanoparticles in D2O is determined to be 125 ± 25 fs. The subsequent decay dynamics of the injected electrons in nanoparticles are found to be different from conduction band electrons in a bulk TiO2 crystal.
Effects of management practices on nematode community structure in tallgrass prairie

Abstract The effects of burning, mowing, and nitrogen (N) and phosphorus (P) fertilization on the trophic structure of a tallgrass prairie nematode community were examined in a long-term field experiment established in 1986. Nematode densities and trophic composition were determined in October of 1987, 1989, and 1994 following 2, 4, and 9 years of treatment, respectively. Total populations of obligate herbivores tended to increase with annual burning and N fertilization but responses by individual taxa were relative to the structure and composition of vegetation as determined by management practice. In contrast, mowing resulted in consistent reductions in herbivore densities. The family Tylenchidae , with species classified as both root and fungal feeders, exhibited short-term decreases in numbers due to burning and long-term increases in numbers due to mowing. Treatment responses by this group were more consistent with the behavior of known fungal-feeding than root-feeding nematodes. Microbivore densities increased with burning and N fertilization, while numbers of omnivores and predators declined with chronic N additions. The effects of P fertilization on nematode population densities varied with management practice, primarily N fertilization. Canonical discriminant analysis differentiated trophic groups based on their responses to mowing and P-fertilization. Measurements of the trophic composition of the nematode community, particularly the relative abundance of individual herbivore taxa and the proportion of fungivores to microbivores, were good indicators of ecosystem responses to management practices.
Architecture of the Smc5/6 Complex of Saccharomyces cerevisiae Reveals a Unique Interaction between the Nse5-6 Subcomplex and the Hinge Regions of Smc5 and Smc6

The evolutionarily conserved structural maintenance of chromosome (SMC) proteins forms the core structures of three multisubunit complexes as follows: cohesin, condensin, and the Smc5/6 complex. These complexes play crucial roles in different aspects of chromosomal organization, duplication, and segregation. Although the architectures of cohesin and condensin are better understood, that of the more recently identified Smc5/6 complex remains to be elucidated. We have previously shown that the Smc5/6 complex of Saccharomyces cerevisiae contains Smc5, Smc6, and six non-SMC elements (Nse1-6). In this study, we investigated the architecture of the budding yeast Smc5/6 complex employing the yeast two-hybrid assay as well as in vitro biochemical approaches using purified recombinant proteins. These analyses revealed that Smc5 and Smc6 associate with each other at their hinge regions and constitute the backbone of the complex, whereas the Nse1-6 subunits form three distinct subcomplexes/entities that interact with different regions of Smc5 and Smc6. The Nse1, -3, and -4 subunits form a stable subcomplex that binds to the head and the adjacent coiled-coil region of Smc5. Nse2 binds to the middle of the coiled-coil region of Smc5. Nse5 and Nse6 interact with each other and, as a heterodimer, bind to the hinge regions of Smc5 and Smc6. These findings provide new insights into the structures of the Smc5/6 complex and lay the foundation for further investigations into the mechanism of its functions.
Tracking predation of subterranean pests: digestion of corn rootworm DNA by a generalist mite

qPCR is a useful tool for understanding predator–prey relationships. We investigated rootworm DNA digestion by male and female predatory mites. Males and females initially consumed comparable amounts of DNA, which was digested at similar rates. Field-collected mites need to be preserved quickly for best qPCR results.
Moderators of Role Stress Among Hospital Personnel

Role ambiguity and role conflict were investigated in two occupational groups within a hospital setting. These role stresses were negatively correlated for both nurses (N = 124) and respiratory therapists (N = 31) with job satisfaction, individual performance, and unit effectiveness. While the possible moderating effects of participation in decision making and tolerance for conflict were generally not supported, the patterns are suggestive of further research.
Cyclosporine A prevents ex vivo PCO formation through induction of autophagy-mediated cell death.

The purpose of this study was to determine the Cyclosporine A (CsA) dose and minimum drug delivery time needed to prevent posterior capsule opacification (PCO) in an ex vivo canine model and evaluate the mechanism of CsA-induced cell death. Canine lens epithelial cells (LEC) were treated with CsA and changes in cell migration, proliferation, and density were monitored over time. CsA-treated LEC underwent transmission electron microscopy (TEM), immunofluorescence, and immunoblotting in the presence or absence of autophagy inhibitors to evaluate the mechanism of cell death. Lens capsules were harvested from canine cadaver eyes for an ex vivo model of PCO. Lens capsules were treated with CsA for 1, 2, 3, 4, 5, 6, or 7 days, and subsequently maintained in culture for a total of 28 days in the absence of drug. CsA reduced LEC viability in a dose dependent manner. Morphologically, CsA-treated LEC were swollen, had intact nuclei, lacked peripheral chromatin condensation, and demonstrated prominent vacuolization; TEM revealed autophagosomes. LC3-II protein expression and acridine orange fluorescence increased in CsA-treated cells. A small non-significant induction of cleaved caspase-3 was observed in CsA-treated LEC. Lens capsules treated with 5, 6, or 7 days of 10 μg/mL CsA showed a significant decrease in ex vivo PCO formation; 6 days of drug delivery prevented PCO. This study finds that morphologic changes, formation of acidic vesicles, and increased expression of LC3-II supports the hypothesis that CsA mediates LEC death via autophagy; this is a novel finding in the lens. Induction of CsA-induced apoptosis was minimal. Six days of intracapsular CsA drug delivery prevented ex vivo PCO formation.
The effect of increasing gastric pH upon the bioavailability of orally-administered foscarnet

For systemic use, the anti-cytomegalovirus (CMV) agent foscarnet must be given intravenously because oral administration results in unmeasurable or barely measurable plasma levels. At low pH, foscarnet decomposes via an acid-catalyzed decarboxylation; therefore, poor oral bioavailability might be due to decomposition of foscarnet in gastric acid. We evaluated whether increasing gastric pH with ranitidine would enhance the absorption of oral foscarnet in six asymptomatic HIV-infected individuals. Each volunteer received two oral 4000-mg (60 mg/kg) doses of foscarnet, preceded intravenously by a 20-min infusion of either ranitidine 50 mg in D5W or D5W alone in a randomized, double-blind, cross-over study. Intragastric pH monitoring revealed that subjects had evidence of gastric acid production (pH 6.0) following ranitidine administration. Most foscarnet plasma levels were below the assay limit of detection (33 microM) with only 4/30 levels detectable after D5W and 8/30 after ranitidine. Urinary recovery of foscarnet increased after ranitidine pretreatment. A mean recovery of 9.9% of the drug was realized in the urine in 24 h following ranitidine pretreatment compared to 6.2% of the dose after D5W pretreatment (P < 0.03). We estimate that 9.9% recovery in the urine in 24 h is equivalent to absorption of 17.1% of the oral dose. In spite of the enhanced bioavailability associated with ranitidine pretreatment, the degree of absorption is still insufficient to achieve effective plasma concentrations for the treatment of CMV or acyclovir-resistant herpes viruses. We conclude that gastric acidity is a determinant of foscarnet absorption, albeit not a major one. Oral foscarnet is unlikely to be clinically useful even if administered in the setting of increased gastric pH.
The fabrication and organization of self-assembled metallic nanoparticles formed in reverse micelles

Abstract Metallic iron nanoparticles are synthesized in reverse micelles of cetyltrimethyl-ammonium bromide (CTAB) using hydrazine as a reducing agent. Once the iron nanoparticles have formed inside the micelle, an aqueous solution of HAuCl 4 is added to the iron/CTAB mixture. Addition of the aqueous gold solution increases the size of the reverse micelle and the Au(III) is reduced to Au(0) via excess hydrazine. Because gold and iron grow with complementary crystal structures, the metallic gold forms a coating on the outer surface of the iron particles. The gold shells on the iron particles provide functionality and thin films of the gold coated particles have been made by self-assembly reactions between the gold surface of the particle and thiol functionalized substrates.
A particle-gamma ray correlation apparatus☆

Abstract An angular correlation apparatus is described in which particles are detected at zero degree with respect to the incident beam by a position sensitive surface barrier detector located at the focal point of a magnetic spectrometer. Four 7.6 cm × 10.2 cm NaI(Tl) crystals are simultaneously used to detect coincident γ-rays at angles between 60° and 160°. Details of precautions taken to reduce γ-ray and particle backgrounds are given. Data are accumulated in three parameter mode using a computer-analyzer system.
The dosimetry of 125I seed eye plaques.

The ability of a brachytherapy treatment‐planning computer program to calculate accurately the dose from 1 2 5I seeds at distances relevant to eye plaque therapy was investigated. Thermoluminescent dosimetry measurements were made in a plastic phantom at depths of 0.5, 0.97, and 1.5 cm, and results were corrected for finite dosimeter size and phantom effects. Doses were calculated at the same depths with an 1 2 5I seed linear source model that accounted for doseanisotropy. Measurements and calculations were found to agree within their mutual uncertainties. The presence of a gold plaque was found to reduce the dose at all measured depths by 8%.
Patterns in habitat and fish assemblages within Great Lakes coastal wetlands and implications for sampling design

Discerning fish–habitat associations at a variety of spatial scales is relevant to evaluating biotic conditions and stressor responses in Great Lakes coastal wetlands. Ordination analyses identifie...
Hudson River: Evidence for extensive migration on the exposed continental shelf during Pleistocene time

Analyses of seismic-reflection profiles collected off New Jersey reveal a large buried channel that splits from the topographic Hudson shelf valley beneath the inner shelf and extends southward for at least 80 km. The buried valley has a flat bottom, a width of 2 to 17 km, and a relief of 3 to 15 m, all features similar to those of the Hudson shelf valley. The buried valley apparently is an ancestral pathway of the Hudson River that has been filled with heterogeneous fluvial deposits and capped by an additional 10 to 30 m of sediments. Vibracores from over or near the ancestral valley show that interbedded marine sand and mud layers constitute the upper part of the sedimentary fill. Radiocarbon ages, geotechnical properties, and micro-paleontological analyses of the core sediments indicate that the valley was formed and filled sometime prior to 28,000 yr ago and then was exposed subaerially during at least one sea-level regression. These results are the first clear subbottom evidence that the ancestral Hudson River flowed south of the Hudson shelf valley on the exposed continental shelf during Pleistocene time.
Structural development during the early stages of polymer melt spinning by in-situ synchrotron X-ray techniques

Recent results from melt spinning of several polymers (nylon 6, polyethylene, poly(vinylidene fluoride) using in-situ simultaneous synchrotron small- and wide-angle X-ray scattering (SWAXS) techniques are summarized. Here, mechanisms of early stages of structural and morphological development during crystallization under melt flow are probed. We find that a model consisting of the formation of defective shish-like structures, followed by the formation of kebab crystals is most consistent with our results. We have further verified that the defective shish structure cannot be detected by the wide-angle X-ray scattering (WAXS) technique, but is visible by small-angle X-ray scattering (SAXS). This model has been proposed by Keller et al., for structural development during elongational flow.
Effect of nucleoside modifications on the structure and thermal stability of Escherichia coli valinetRNA

Transfer RNA transcribed in vitro lacks the base modifications found in native tRNA. To understand the effect of base modifications on the structure of tRNA, the downfield region of the 1H NMR spectrum of in vitro transcribed E coli tRNAVal in aqueous phosphate buffer in the presence of excess Mg2+ was investigated. The resonances of all imino protons involved in hydrogen bonds in the helical stem regions and in tertiary interactions were assigned using two-dimensional nuclear Overhauser enhancement spectroscopy (NOESY) and one-dimensional difference nuclear Overhauser effect (NOE) methods. In addition, some aromatic C2 and C8 proton resonances as well as one amino proton resonance were assigned. The chemical shifts of the assigned resonances of unmodified E coli tRNAVal were compared with those of the native tRNA molecule under similar solution conditions. The similarity of the NMR data for unmodified and modified tRNA indicates that the in vitro transcribed tRNA has nearly the same solution structure as the native molecule in the presence of excess Mg2+. The only significant differences were the chemical shifts of resonances corresponding to protons in (or interacting with) bases, indicating the possibility of local structural perturbations. The thermal stability of E coli modified and unmodified tRNAVal in the presence of Mg2+ was also investigated by analyzing the temperature dependence of the imino proton spectra. Several tertiary interactions involving modified nucleosides in native E coli tRNAVal are less stable in the absence of base modifications.
Intention for Entrepreneurship among Students in India

The purpose of this research was to study what a group of university students in India intended to do upon completion of their college education: start their own business (become entrepreneurs) or ...
Adrenal medullary transplants as a treatment for advanced Parkinson's disease.

It is no coincidence that human neural transplantation currently focuse on Parkinson’s Disease. In PD, of all the neurodegenerative disorders, there is the clearest relationship between the pathology [the loss of catecholamine containing pigmented neurons in the substantia nigra pars compacta (SNpc)], the neurochemistry [the loss of striatal dopamine (DA)] the pathophysiology (the disinhibition of the striatum), and the clinical symptoms. Moreover, the loss of tissue in PD is small and restricted to the SNpc. It was reasonable to expect that if a transplant could substitute for the lost SNpc neurons in patients with PD, then symptoms might improve.
Intra-industry trade in the European dairy industry

This paper examines bilateral intra-industry trade (IIT) in the EU dairy products industry during 1988-92, in order to assess whether both country-specific and industry-specific factors determine this component of trade flows. It is shown that IIT in dairy products between pairs of countries is negatively related to the variables indicating inequality between the two countries. Two-way flows are thus more significant, the more similar the countries are. The coefficients for the variables describing industry structure suggest that the presence of large firms with an absolute cost advantage over smaller firms stimulates IIT-enhancing non-price competition. Concentration in the retail sector was found to have a negative effect on II, which conflicts with our original hypothesis. Copyright 1997 by Oxford University Press.
Optimization of a lattice Boltzmann computation on state-of-the-art multicore platforms

We present an auto-tuning approach to optimize application performance on emerging multicore architectures. The methodology extends the idea of search-based performance optimizations, popular in linear algebra and FFT libraries, to application-specific computational kernels. Our work applies this strategy to a lattice Boltzmann application (LBMHD) that historically has made poor use of scalar microprocessors due to its complex data structures and memory access patterns. We explore one of the broadest sets of multicore architectures in the high-performance computing (HPC) literature, including the Intel Xeon E5345 (Clovertown), AMD Opteron 2214 (Santa Rosa), AMD Opteron 2356 (Barcelona), Sun T5140 T2+ (Victoria Falls), as well as a QS20 IBM Cell Blade. Rather than hand-tuning LBMHD for each system, we develop a code generator that allows us to identify a highly optimized version for each platform, while amortizing the human programming effort. Results show that our auto-tuned LBMHD application achieves up to a 15 times improvement compared with the original code at a given concurrency. Additionally, we present a detailed analysis of each optimization, which reveals surprising hardware bottlenecks and software challenges for future multicore systems and applications.
Thermal Degradation of Famotidine in Aqueous Solution Stability Indicating Assay

Abstract A High Pressure Liquid Chromatographic Method is described for the determination of famotidine in aqueous solution. The assay method is capable of distinguishing famotidine from its thermal degradation products in the pH range of 1.7–10.0. Famotidine and the internal standard sulfacetamide eluted in 13 minutes with retention times of 10 and 5.7, respectively. A linear relationship between peak height ratio (famotidine/sulfacetamide) and famotidine concentration was found up to 60 μg/ml. The coefficient of variation of the assay method over several days ranged from 0.2 to 5.1% in the concentration range of 4–57 μg/ml.
The effect of respiratory motion variability and tumor size on the accuracy of average intensity projection from four-dimensional computed tomography: an investigation based on dynamic MRI.

Composite images such as average intensity projection (AIP) and maximum intensity projection (MIP) derived from four-dimensional computed tomography (4D-CT) images are commonly used in radiation therapy for treating lung and abdominal tumors. It has been reported that the quality of 4D-CT images is influenced by the patient respiratory variability, which can be assessed by the standard deviation of the peak and valley of the respiratory trajectory. Subsequently, the resultant MIP underestimates the actual tumor motion extent. As a more general application, AIP comprises not only the tumor motion extent but also the probability that the tumor is present. AIP generated from 4D-CT can also be affected by the respiratory variability. To quantitate the accuracy of AIP and develop clinically relevant parameters for determining suitability of the 4D-CT study for AIP-based treatment planning, real time sagittal dynamic magnetic resonance imaging (dMRI) was used as the basis for generating simulated 4D-CT. Five-minute MRI scans were performed on seven healthy volunteers and eight lungtumor patients. In addition, images of circular phantoms with diameter 1, 3, or 5 cm were generated by software to simulate lungtumors. Motion patterns determined by dMRI images were reproduced by the software generated phantoms. Resorted dMRI using a 4D-CT acquisition method (RedCAM) based on phantom or patient images was reconstructed by simulating the imaging rebinning processes. AIP images and the corresponding color intensity projection (CIP) images were reconstructed from RedCAM and the full set of dMRI for comparison. AIP similarity indicated by the Dice index between RedCAM and dMRI was calculated and correlated with respiratory variability ( v ) and tumor size ( s ) . The similarity of percentile intrafractional motion target area (IMTA), defined by the area that the tumor presented for a given percentage of time, and MIP-to-percentile IMTA similarity as a function of percentile were also determined. As a result, AIP similarity depends on both respiratory variability and tumor sizes. The AIP similarity correlated linearly with the respiratory variability normalized by tumor sizes ( R 2 equal to 0.82 and 0.91 for the phantom study and the patient study, respectively). For both studies, MIP derived from RedCAM was close to the area that the tumor presented 90% or more of the time and missed the region where the tumor appeared less than 10% of the time. In conclusion, the accuracy of composite images such as AIP and MIP derived from 4D-CT to define the tumor motion and position is affected by patient-specific respiratory variability and tumor sizes. Based on our study, normalized respiratory variability appears to be a pertinent parameter to assess the suitability of a 4D-CT image set for AIP-based treatment planning.
Efficient exploration of reaction paths via a freezing string method.

The ability to efficiently locate transition states is critically important to the widespread adoption of theoretical chemistry techniques for their ability to accurately predict kinetic constants. Existing surface walking techniques to locate such transition states typically require an extremely good initial guess that is often beyond human intuition to estimate. To alleviate this problem, automated techniques to locate transition state guesses have been created that take the known reactant and product endpoint structures as inputs. In this work, we present a simple method to build an approximate reaction path through a combination of interpolation and optimization. Starting from the known reactant and product structures, new nodes are interpolated inwards towards the transition state, partially optimized orthogonally to the reaction path, and then frozen before a new pair of nodes is added. The algorithm is stopped once the string ends connect. For the practical user, this method provides a quick and convenient way to generate transition state structure guesses. Tests on three reactions (cyclization of cis,cis-2,4-hexadiene, alanine dipeptide conformation transition, and ethylene dimerization in a Ni-exchanged zeolite) show that this “freezing string” method is an efficient way to identify complex transition states with significant cost savings over existing methods, particularly when high quality linear synchronous transit interpolation is employed.
Large-scale forcing of environmental conditions on subarctic copepods in the northern California Current system

In the ocean, dominant physical processes often change at various spatial and temporal scales. Here, we examined associations between large-scale physical forcing indexed by the Pacific Decadal Oscillation (PDO), regional ocean conditions including alongshore currents in relation to the abundance of two subarctic oceanic copepods, Neocalanus plumchrus, and N. cristatus in the offshore portions of the northern California Current (NCC) system in spring of 1998–2008. We found significant relationships between the abundance of copepods, water temperature, and alongshore currents with a lag of two or four months in response to the PDO in the NCC system. During the growth season in March/April both subarctic copepod species displayed consistent cross-shelf patterns with shoreward decreasing gradient in abundance, and were negatively correlated with the PDO, sea water temperature, and alongshore currents. Our studies highlight the responses of regional ocean conditions to large-scale physical forcing and illustrate the potential for Neocalanus copepods as unique vectors for a new understanding of the ecological response in the offshore oceanic waters of the NCC system to climate variability.
Dynamic selection of k nearest neighbors in instance-based learning

kNN is a popular lazy-learning algorithm used for a wide variety of machine learning applications. One problem with this algorithm is the choice of k value. Different k values can have a large impact on the predictive accuracy of the algorithm, and picking a good value is generally unintuitive by looking at the data set. Cross-validation over multiple folds is often used to find the best value for k in kNN based on prediction results. In this paper, we propose automatic selection of neighboring instances as defined by a dynamic local region unique to each instance, as opposed to the traditional approach of considering the manually specified k nearest neighbors. Removing the need to select an appropriate k value removes the cross-validation step, which improves the computational performance of the algorithm. Classification accuracy achieved by this approach is only slightly lower than the results of using kNN with an optimally selected k value.
Subpicosecond laser breakdown in optical thin films

Experimental and theoretical progress on subpicosecond laser pulse breakdown in dielectric films is reviewed. The single pulse threshold fluences can be related to fundamental material properties and scaling laws with respect to pulse duration and material bandgap are discussed. Multiple pulse thresholds are controlled by native and laser-induced defects. A phenomenological model is introduced that describes the accumulation and relaxation of such defects. The model is able to explain the experiments and can be used to assess relevant defect parameters. Experimental results are presented that exemplify how the ambient atmosphere affects the multiple pulse laser damage thresholds.
Comprehensive family-based association study of the glutamate transporter gene SLC1A1 in obsessive-compulsive disorder.

SLC1A1 encodes a neuronal glutamate transporter and is a promising candidate gene for obsessive-compulsive disorder (OCD). Several independent research groups have reported significant associations between OCD and single nucleotide polymorphisms (SNPs) in this gene. Previously, we evaluated 13 SNPs in, or near, SLC1A1 and reported a strong association signal with rs301443, a SNP 7.5 kb downstream of the gene (Shugart et al., 2009). The aims of the current study were first, to further investigate this finding by saturating the region around rs301443; and second, to explore the entire gene more thoroughly with a dense panel of SNP markers. We genotyped an additional 111 SNPs in or near SLC1A1, covering from 9kb upstream to 84kb downstream of the gene at average spacing of 1.7kb per SNP, and conducted family-based association analyses in 1,576 participants in 377 families. We found that none of the surrounding markers were in linkage disequilibrium with rs301443, nor were any associated with OCD. We also found that SNP rs4740788, located about 8.8 kb upstream of the gene, was associated with OCD in all families (P=0.003) and in families with male affecteds (P=0.002). A 3-SNP haplotype (rs4740788-rs10491734-rs10491733) was associated with OCD in the total sample (P=0.00015) and in families with male affecteds (P=0.0007). Although of nominal statistical significance considering the number of comparisons, these findings provide further support for the involvement of SLC1A1 in the pathogenesis of OCD.
Coherence and the credibility of convertibility announcements

Abstract The recent devaluation crisis in Mexico and its `tequila effect' elsewhere illustrate that two credibility problems associated with convertibility policies (currency boards) are announcements that violate truth-telling, and a non-zero probability of policy failure. We derive the trade-off between these problems when announcements resemble cheap talk. The strategic uncertainty created by this trade-off implies that both the government and investors should recognize the presence of `Fed watchers', who exploit any policy inconsistency for their own gain. In this context, credibility can be restored if the policy is coherent — if it eliminates the marginal benefits for Fed watching. (JEL E63, E58, F40). © 1997 Published by Elsevier Science Ltd.
Synthesis, Peripheral Studies, and Structural Investigation of (1:1) Mn II3 [(CoIII/CrIII)(CN)6]2 ·? 14H2O

Abstract The crystal structure of (1:1) Mn3[(Co/Cr)(CN)6]2 · 14H2O has been determined by single-crystal diffractometry and refined by the full-matrix least-squares method to yield R = 0.030 and Rw = 0.036 based on 114 unique reflections. This first studied mixed anionic hexacyanide crystallizes in the cubic system (space group Fm3m , No. 225) with a = 10.470(1) A. The disordered structure contains 113 molecules in the unit cell. The experimental density is 1.61(1) Mg m-3 (calculated, 1.620 Mg m-3). A thermal gravimetric analysis yielded 13-14 water molecules per formula unit. All metal atoms are six-coordinated octahedrally and linkage between the cationic and the (1:1) mixed anionic metals is accomplished by cyanide bridging. Conoscopic and infrared spectral results are presented as well as important bond and contact distances.
Association of intraoperative hypotension and pulmonary hypertension with adverse outcomes after orthotopic liver transplantation.

Abstract Background Various preoperative, surgical, and postoperative markers of impaired outcome after orthotopic liver transplantation have been reported, but the influence of intraoperative hemodynamic aberrations has not been thoroughly investigated. Setting University Hospital. Study design Retrospective cohort analysis. Methods The authors retrospectively reviewed computerized anesthesia records to determine associations between occurrences of abnormally low or high mean pulmonary artery pressure (MPAP), cardiac output, heart rate, systolic arterial pressure, diastolic arterial pressure, and mean arterial pressure (MAP) with negative surgical outcome. Negative surgical outcome was defined as poor early graft function, primary graft nonfunction, or death attributable to hemodynamic causes. Results Of 789 patients, 142 (18.0%) had negative surgical outcome. Controlling for the influence of United Network for Organ Sharing (UNOS) status > 1, long operation time, cold donor organ ischemia time, and donor age, the only hemodynamic parameters that were independently associated with negative surgical outcome were MAP 40 mmHg at least 3 times during the procedure (OR 2.2, p = 0.035). The occurrence of MAP Conclusions Hemodynamic events are independently associated with adverse outcomes after orthotopic liver transplantation.
Quantitative-Trait Loci Influencing Body-Mass Index Reside on Chromosomes 7 and 13: The National Heart, Lung, and Blood Institute Family Heart Study

Obesity is a risk factor for many chronic diseases, including glucose intolerance, lipid disorders, hypertension, and coronary heart disease. Even though the body-mass index (BMI) is a heterogeneous phenotype reflecting the amount of fat, lean mass, and body build, several studies have provided evidence of one or two major loci contributing to the variation in this complex trait. We sought to identify loci with potential influence on BMI in the data obtained from National Heart, Lung, and Blood Institute Family Heart Study. Two complementary samples were studied: ( a ) 1,184 subjects in 317 sibships, with 243 markers typed by the Utah Molecular Genetics Laboratory (UMGL) and ( b ) 3,027 subjects distributed among 401 three-generation families, with 404 markers typed by the Mammalian Genotyping Service (MGS). A genome scan using a variance-components–based linkage approach was performed for each sample, as well as for the combined sample, in which the markers from each analysis were placed on a common genetic map. There was strong evidence for linkage on chromosome 7q32.3 in each sample: the maximum multipoint LOD scores were 4.7 ( P −5 ) at marker GATA43C11 and 3.2 ( P =.00007) at marker D7S1804, for the MGS and UMGL samples, respectively. The linkage result is replicated by the consistent evidence from these two complementary subsets. Furthermore, the evidence for linkage was maintained in the combined sample, with a LOD score of 4.9 ( P −5 ) for both markers, which map to the same location. This signal is very near the published location for the leptin gene, which is the most prominent candidate gene in this region. For the combined-sample analysis, evidence of linkage was also found on chromosome 13q14, with D13S257 (LOD score 3.2, P =.00006), and other, weaker signals (LOD scores 1.5–1.9) were found on chromosomes 1, 2, 3, 5, 6, 14, and 15.