cssi/SciSciGPT-SciSciNet huggingface dataset:
A selective sexually dimorphic response in the median eminence neuropeptide Y

Recent studies show that neuropeptide Y (NPY) is widely distributed in the hypothalamus and that it stimulates luteinizing hormone-releasing hormone (LHRH) release from the medial basal hypothalamus (MBH) of male and female rats. The neuroendocrine factors that regulate NPY neurosecretion in two sexes are not well understood. We have previously observed that orchidectomy (orch) in male rats decreased and testosterone (T) replacement increased NPY levels selectively in the median eminence (ME), arcuate nucleus (ARC) and ventromedial nucleus (VMN) and the KCl-evoked in vitro release of NPY from the MBH was likewise decreased after orch and restored by testosterone replacement. Now we report that these NPY responses are different in female rats following removal of the ovaries. Ovariectomy (ovx) decreased NPY concentrations in the ARC and VMN and not in the ME. Estrogen replacement restored NPY concentrations in the ARC and VMN, however, in the ME NPY concentration decreased significantly. Further, the KCl-evoked NPY release in vitro from either the MBH or ME of intact and ovx rats was similar. In an additional concurrent comparative study in male and female rats, we observed that of the 6 microdissected hypothalamic sites, NPY levels were approximately 50% less in the ME of intact females than in those of intact male rats. Again, in male rats there was a significant decrease in NPY levels in the ME, ARC and VMN after orch, whereas in female rats, NPY levels in the ARC and VMN, but not in the ME decreased after ovx.(ABSTRACT TRUNCATED AT 250 WORDS)
Psychosocial disability during maintenance hemodialysis.

Abstract Overall psychosocial functioning was assessed in 21 maintenance hemodialysis patients. The Ruesch Social Disability Scale, which provides an overall Social Disability (DS) score as well as subscores for Physical Impairment (PI), Behavioral Impairment (BI), and Social Modifiers (MS), was utilized. A majority of the patients (13) experienced Major Social Disability and the mean DS score of this sample was in the Major Social Disability range ( x = 52.1 ± 10.9). There were no differences between the mean DS score of men and women. Married patients had DS scores significantly lower than those who were divorced or never married ( P P P
Fourier transform ion cyclotron resonance mass spectrometry: A primer

This review offers an introduction to the principles and generic applications of FT-ICR mass spectrometry, directed to readers with no prior experience with the technique. We are able to explain the fundamental FT-ICR phenomena from a simplified theoretical treatment of ion behavior in idealized magnetic and electric fields. The effects of trapping voltage, trap size and shape, and other nonidealities are manifested mainly as perturbations that preserve the idealized ion behavior modified by appropriate numerical correction factors. Topics include: effect of ion mass, charge, magnetic field, and trapping voltage on ion cyclotron frequency; excitation and detection of ICR signals; mass calibration; mass resolving power and mass accuracy; upper mass limit(s); dynamic range; detection limit, strategies for mass and energy selection for MSn; ion axialization, cooling, and remeasurement; and means for guiding externally formed ions into the ion trap. The relation of FT-ICR MS to other types of Fourier transform spectroscopy and to the Paul (quadrupole) ion trap is described. The article concludes with selected applications, an appendix listing accurate fundamental constants needed for ultrahigh-precision analysis, and an annotated list of selected reviews and primary source publications that describe in further detail various FT-ICR MS techniques and applications. © 1998 John Wiley & Sons, Inc., Mass Spec Rev 17, 1–35, 1998
Effect of Five-Year Continuous Poultry Litter Use in Cotton Production on Major Soil Nutrients

Repeated application of poultry (Gallus gallus) litter to crop lands may lead to nitrates leaching and build up of P and other elements in the soil profile, which are prone to loss from runoffand erosion. A study was conducted for 5 yr at Belle Mina, AL on a Decatur silt loam (fine, kaolinitic thermic Rhodic Paleudult) during 1994 to 1998 to determine the nitrate movement and quantify the build up of P, K, Ca, and Mg due to the application of nitrification inhibitor, carboxymethyl pyrazole (CP), treated fresh and composted poultry litter and urea in conventionally tilled cotton (Gossypium hirsutum L.). Poultry litter maintained soil pH (0-30 cm depth) where as application of urea resulted in a pH decline. The inhibitor, CP, significantly reduced the NO 3 - -N formation in all N sources for 41 d following application. However, over the longer period of time, very minimal changes in nitrate concentrations were observed due to change in rates or sources of N. Over the experimental period, P concentration increased significantly (by 74%) in composted litter applied plots (17.7 mg kg -1 ) but not in fresh litter plots (1.5 mg kg -1 ). Linear increase in P accumulation was observed with increase in rate of composted litter. Concentrations ofK and Mg increased significantly both in fresh (93 and 25 mg kg -1 , respectively) and composted litter (127 and 36 mg kg -1 , respectively) applied plots by the end of 5 yr period. These results indicate that a well-planned application of fresh poultry litter in soils that are not already overloaded with P is safe and treating litter with CP is advantageous from an environmental perspective.
Performance of US contractors in foreign markets

The international construction market shrank considerably in the period 1980–88. US contractors' performance in this period was less than satisfactory. This paper first discusses briefly the principal causes for this decline in international construction (the reduction in oil prices, an increase in Third World countries' external debts, local companies becoming more competitive, and governments' barriers to foreign contractors). It then uses published statistical data to identify the common features of US construction companies that undertake work overseas. Finally, it attempts to explain the factors such as financing, taxing, the Foreign Corrupt Practices Act, and foreign competition that may have affected US competitiveness abroad.
N-terminal Truncation of Prion Protein Affects Both Formation and Conformation of Abnormal Protease-resistant Prion Protein Generatedin Vitro *

Transmissible spongiform encephalopathy diseases are characterized by conversion of the normal protease-sensitive host prion protein, PrP-sen, to an abnormal protease-resistant form, PrP-res. In the current study, deletions were introduced into the flexible tail of PrP-sen (23) to determine if this region was required for formation of PrP-res in a cell-free assay. PrP-res formation was significantly reduced by deletion of residues 34-94 relative to full-length hamster PrP. Deletion of another nineteen amino acids to residue 113 further reduced the amount of PrP-res formed. Furthermore, the presence of additional proteinase K cleavage sites indicated that deletion to residue 113 generated a protease-resistant product with an altered conformation. Conversion of PrP deletion mutants was also affected by post-translational modifications to PrP-sen. Conversion of unglycosylated PrP-sen appeared to alter both the amount and the conformation of protease-resistant PrP-res produced from N-terminally truncated PrP-sen. The N-terminal region also affected the ability of hamster PrP to block mouse PrP-res formation in scrapie-infected mouse neuroblastoma cells. Thus, regions within the flexible N-terminal tail of PrP influenced interactions required for both generating and disrupting PrP-res formation.
High-performance ion-exchange chromatography and adsorption of plasma proteins

Abstract Resolution and recovery are primary concerns in protein chromatography. Separations are often by size, ion exchange, or hydrophobic–hydrophilic properties of the support, eluent and protein. Adsorption of a protein to a synthetic surface plays an essential role in this complex process. In this study, we examined the adsorption properties of three representative plasma proteins (albumin, fibrinogen, and immunoglobulin G) on nonporous column materials containing either quaternary amine or sulfopropyl functional groups. The adsorption properties were studied at 37°C and pH 7.4. Salt gradients were used to examine the adsorption/desorption properties of each of the proteins on each type of surface. The salt concentrations at desorption were measured and compared to the protein isoelectric points. In addition, we examined protein recoveries as a function of desorption time. Our results suggest that protein recoveries depend not only on the protein, eluent and surface, but also the residence time and overall charge concentration during the initial adsorption process. Finally, we correlated the number of charge sites on a molecule with the width of a chromatographic band at half height. The data produced as a result of this study may be used to determine the actual unfolding time of a protein, given a certain set of conditions. The data may also help in understanding the chemistry and dynamics of the protein adsorption processes in ion-exchange chromatography as well as provide key structural information about the proteins.
Smectic phase structures of cyanodicyclohexyl liquid crystals

Abstract The smectic phase structures of p-ethyl-and p-butyl-p'-cyanocyclohexyl-cyclohexane (ECCH and BCCH) have been found to be quite different from each other despite the similarities in molecular structures. The former structure is close to rhombohedreal with a = b= c = 12.5 a, α= β= γ= 28ag and one molecule per unit cell. In contrast, the latter structure is close to hexagonal close-packed with a = b = 5.7 α and c = 31 a and two molecules per unit cell. Since intermolecular forces may be quite weak in these systems, it appears that crystal structure can change considerably even through molecular structure is only slightly altered. An X-ray image intensification device (the Lixiscope) is helpful in the search for symmetric diffraction patterns.
Affective Traits, Responses to Conflict, and Satisfaction in Romantic Relationships

Abstract Participants described their current and past romantic relationships on a variety of measures, as well as their typical behavioral responses to conflict in intimate relationships. Consistent with studies of initial social encounters, participants who were high in trait positive affect (PA) described their current relationships as being of higher quality than did low PA individuals. Participants who were high in PA were also more likely to currently be in a relationship than were other people. Negative affect emerged as a predictor of the amount of conflict that characterized people's past romantic relationships. Analyses further revealed that the link between PA and relationship quality was mediated by high PA individuals' reluctance to engage in active destructive responses and propensity to engage in active, constructive responses to conflict with their partner.
Foster parents of cocaine-exposed infants

The purpose of this study was to describe the experience of foster parents of cocaine-exposed infants. A qualitative approach was selected because of the paucity of knowledge on the topic. Results showed foster parents observed alterations in physiological and behavioral health, developmental problems, and variability among infants related to these problems. Foster parents were concerned about the future development of infants. They felt the experience of living with a cocaine-exposed infant gave them a unique view of the effects of exposure. Parents found difficulties obtaining social services. Foster parents reported problems with access to and appropriateness of health care and identified difficulties arising from community reaction to foster parenting. Recommendations focused on the need for more research on social, developmental, and behavioral effects of cocaine exposure and increased attention to the needs and concerns of foster parents.
Computer anxiety in management: myth or reality?

Although many informal surveys in the business press have contended that computer anxiety has a significant adverse impact on managers' willingness to use microcomputers, the problem is neither as extensive nor as severe as once believed.
Geometrical properties of bone sections determined by laminography and physical section

Abstract The cortical bone areas and second moments of area were calculated for five human tibias using both physical sections and laminograms. Calculations based upon the laminograms tended to slightly overestimate second moments of area about the principal axes, but average error was less than 6% for both maximum and minimum values, demonstrating that laminography is an effective noninvasive technique for the determination of geometrical properties of long bones.
Response to the discussion by I.V. Rokach of the paper entitled: “Analysis of the dynamic responses for a pre-cracked three-point bend specimen”

The following response to the discussion of the above mentioned paper is divided into two parts: (1) a response to the issue of our comparison of the ‘apparent period of specimen oscillation’, τ, and the natural vibration period of a cracked specimen, T, and (2) a verification of the applicability of our model to ‘short time-to-fracture’ tests, which Rokach has questioned, due to a lack of knowledge of Hopkinson bar techniques.
Report On ‘ChemLinks: Changing the Way Students Learn Chemistry’

ChemLinks is a collaborative effort by over seventy active participants from twenty-four academic institutions to write, test, and disseminate topical modules to be used to teach chemistry in the first and second years of the college curriculum. Twenty-four modules are currently under development and an additional seven will be started this year. In this workshop the leaders discussed the plan and philosophy behind this project and presented components from two modules as examples.
Angular distribution of sputtered atoms in physical vapor deposition and collimated sputtering

Collimated sputtering has been studied for a number of years as a possible technique for improving step coverage and feature fill in integrated circuit (IC) metallization. The collimator is a physical filter which blocks sputtered atoms which possess an incident angle greater than the arc-cotangent of the collimator aspect ratio. Those atoms with angles less than this amount are allowed to pass through and deposit on the wafer, though an angle-dependent fraction are still blocked by the collimator. Atoms with low incident angles are able to get down into high aspect ratio features much more effectively than those with higher angles. Equations are derived for predicting the fraction of incident atoms transmitted through a collimator and the angular distribution of atoms arriving at the wafer for both collimated and uncollimated sputtering. Target utilization for collimated sputtering was found to be only 10 to 15% of that for uncollimated sputtering, even when gas scattering effects are neglected. Long-throw sputtering offers higher target utilization, but is not as effective due to excessive gas scattering.
Prospects for hybrid electronics

This paper discusses established electronics technology with prospects for incorporation of high critical temperature (Ta) superconductors, the projected results of introducing superconductors into conventional semiconductor electronics, and processing issues in the construction of hybrid devices.
Breaded Fried Chicken: Effects of Precooking, Batter Composition, and Temperature of Parts before Breading

Abstract INTEREST in different cooking methods for chicken has increased in recent years. Carlin et al. (1959) found that pre-cooked parts from frozen chicken averaged 20 to 26 percent loss from the raw state to the ready-to-eat product; whereas, non-precooked controls averaged 16 percent losses. Mickelberry and Stadelman (1962) observed lower cooking losses were obtained when chicken was partially cooked with steam and finished by deep-fat frying as compared with other methods involving deep-fat frying. Contradictory results were reported by Smith and Vail (1963). These authors reported no significant differences in yield due to cooking methods of skillet-frying, deep-fat frying, and oven frying. Skin from deep-fat fried chicken was found to contain 40 percent fat as compared to 31 percent and 33 percent for oven-fried and skillet-fried, respectively (Smith and Vail, 1962). Mostert and Stadelman (1964) reported that breading increased fat absorption when cooked by methods where fat was used. Pressure . . .
Production of sperm reduces nematode lifespan

SEX and death are two fundamental but poorly understood aspects of life1–3. They are often thought to be linked because reproduction requires the diversion of limited resources from somatic growth and maintenance4–9. This diversion of resources in mated animals, often called a cost of reproduction, is usually expressed as a reduction of lifespan in mated animals, although some debate exists on the best way to measure this cost4–6,9,10. I report here that in the soil nematode, Caenorhabditis elegans, sex significantly decreases male lifespan without reducing hermaphrodite lifespan. The reduction of mated male lifespan seems to be caused by additional sperm production and not by the physical activity of mating. This conclusion is supported by observations that a mutation reducing sperm production increased mean lifespan by about 65% in both mated males and hermaphrodites. This suggests that spermatogenesis, rather than oogenesis or the physical act of mating, is a major factor reducing lifespan in C. elegans. This contradicts the traditional biological assumption that large oocytes are much costlier to produce than small sperm11–14.
An impedance-based approach to HVDC system stability analysis and control development

High-voltage dc (HVDC) transmission system stability has traditionally been studied using state-space models and eigenvalue analysis. The state-space approach requires design details of each component of the HVDC grid, which is usually not available, and does not support local control development at individual terminals. This paper presents an impedance-based approach to HVDC system stability analysis that is easier to apply and supports local and adaptive control development. Representation of a HVDC system by an impedance equivalent circuit is presented first. Analytical impedance models are then developed for different HVDC converters to support system impedance analysis. The ability of impedance-based analysis to predict and mitigate different control and system instability problems are demonstrated and verified by detailed circuit simulation.
Detrimental effects of searching with precoordinated terms

A ‘precoordinated’ term in a controlled vocabulary is a term that combines two concepts with Boolean AND prior to the act of indexing or searching. For example, the term Library Automation combines the concept of ‘libraries’ with the concept of ‘automation’. By using Library Automation as a search term, one may avoid having to create and intersect separate facets.
High temperature superconducting granular balls

Abstract When a strong electric field is applied to a suspension of micron-sized high Tc superconducting particles in liquid nitrogen, the particles quickly aggregate together to form balls. The millimeter-size balls hold over 106 particles each. They are sturdy, surviving constant heavy collisions with the electrodes. The ball formation is a results of superconductivity. As the c-axis coherence length is shorter than the Thomas-Fermi screening length, the electric field produced by the charged surface layer turns off the coupling between the interlayers. This loss of Josephson energy becomes a positive surface energy. Its minimization leads to the balls.
Object Individuation in Infancy: The Use of Featural Information in Reasoning about Occlusion Events

Abstract Recent findings by Xu and Carey (1996) indicate that, after seeing two distinct objects (e.g., a duck and a ball) emerge on the opposite sides of a screen, 10-month-olds show no surprise when the screen is removed to reveal one (e.g., a duck) as opposed to two objects (e.g., a duck and a ball). The authors took their results to mean that 10-month-olds are unable to use featural information to individuate objects. The present research examined a different interpretation of the results. This interpretation was based on a distinction betweenevent mapping,in which infants see a sequence of two distinct events and judge whether the two are consistent, andevent monitoring,in which infants see a single event and judge whether successive portions of the event are consistent. The present research contrasted infants' performances in event-mapping tasks in which they saw first an occlusion and then a no-occlusion situation (as in Xu & Carey) and in event-monitoring tasks in which they saw only an occlusion situation. It was hypothesized that infants would be more likely to give evidence of correct individuation when tested with the event-monitoring as opposed to the event-mapping tasks. Eight experiments were conducted with infants ages 7.5 to 11.5 months. These experiments yielded two main findings. First, when tested with an event-monitoring task, even 7.5-month-olds give evidence that they can use featural information to individuate the objects involved in an occlusion event. Second, when tested with an event-mapping task, even 9.5-month-olds give evidence that they can use featural information to interpret an occlusion event as long as the event is made extremely simple. These findings give weight to the distinction between event mapping and monitoring and more generally begin to shed light on the fundamental processes involved in infants' formation and use of event representations.
Quadratic programming for learning sparse codes

Olshausen and Field (1996) used a neural network, capable of discovering sparsely distributed representations by using the principle of redundancy reduction, for the efficient coding of natural images. They showed how the resulting response functions of the units relate to the properties of simple cells in the mammalian primary visual cortex. In order to model the function of later stages of visual processing in mammals, the activation patterns of this network could be used as an input to another one of similar architecture. It would therefore be advantageous if these patterns could be calculated fast. Moreover, not only speed but also accuracy would be an important issue if the network was to be used in practical applications, such as image compression. We have derived an algorithm that achieves both goals with far less computational effort than gradient descent based minimizers.
Longitudinal follow up of elevated pulmonary artery pressures in children with sickle cell disease

Elevated pulmonary artery pressures (PAP) occur in approximately 30% of children with sickle cell disease. In adults, pulmonary hypertension is significantly associated with mortality. There are no data on the long term significance in children. Nineteen children with SS/Sbeta(0) thalassaemia had elevated PAP, defined as tricuspid regurgitant jet velocity (TRV) > or =2.5 m/s on screening echocardiograms. They were prospectively followed for 23 months (range 19-31 months). Patients with initial TRV > or = 3 or TRV > or = 2.5 m/s on repeat echocardiogram had cardiopulmonary evaluation and were offered treatment with hydroxyurea. Associated conditions like asthma and obstructive sleep apnea were treated. 18/19 patients had follow-up echocardiograms. These showed normalization of TRV in 8 patients. Risk factors associated with persistent elevation were higher TRV on initial echocardiogram (P = 0.01), lower haemoglobin (P = 0.003) and lower oxygen saturation (P = 0.03). Five patients with persistently elevated PAP were treated with hydroxyurea. Mean right ventricular pressure dropped from 40.16 to 29.26 (P = 0.017) after 3-6 months and to 23.6 mmHg (P = 0.002) after 9-12 months on treatment. In conclusion (i) At borderline elevation of TRV there is intrapatient variability and echocardiograms should be repeated for confirmation. (ii) Elevated PAP are reversible in children with early detection and treatment with hydroxyurea.
Intraoperative imprint cytology for evaluation of sentinel lymph nodes from visceral malignancies

Although originally described for breast cancer and melanoma, sentinel lymph node (SLN) mapping techniques are being investigated in the treatment of visceral malignancies. There is no literature evaluating intraoperative analysis of SLNs from visceral sites. We evaluated the utility of touch preparation intraoperative imprint cytology (IIC) in evaluating SLNs harvested in the setting of visceral malignancy. SLN mapping procedures involving 50 cases of visceral malignancy (37 colon, 12 gastric, and 1 small bowel), from February 1999 through August 2001, were studied. In each case, subserosal injections of isosulfan blue were used to identify the SLN. The SLNs were then sent fresh to the pathology laboratory for evaluation by IIC. A standard lymphadenectomy was performed in all cases. Postoperatively, the SLNs were evaluated by means of using hematoxylin and eosin staining. If these stains were normal, immunohistochemical analyses using carcinoembryonic antigen and cytokeratin were subsequently performed. SLNs were successfully identified in 46 cases (92%), and a total of 95 SLNs were harvested. The average number of SLNs was 1.9 with a range of one to six. More SLNs were found with gastric than with colonic lesions (2.8 vs. 1.8; P = .017). Evaluable IIC in 41 cases revealed metastatic disease in 10 SLNs, representing seven patients. Of the 34 patients with normal IIC, five were found to have positive SLNs on hematoxylin and eosin staining. An additional three patients were found to have positive SLNs only on immunohistochemical analysis. The overall sensitivity and specificity of IIC was 64% and 100%, respectively. This resulted in a positive predictive value of 100% and a negative predictive value of 86%. The use of IIC to evaluate SLNs from visceral malignancies is clearly feasible. When the IIC of the SLN is positive, the surgeon may feel confident that disease is actually present in the SLN. If there is a negative result, the technique may miss disease that is present on subsequent permanent sections. We do not recommend routine use of IIC; however, it may be of use in clinical trials.
Light Propagation through a Turbulent Atmosphere: Measurements of the Optical Filter Function

Two He–Ne lasers operating at 6328 A have been utilized to make simultaneous measurements of the effects of scintillation over homogeneous optical paths of 650 and 1300 m to study the transfer of laser radiation through a turbulent medium. At the path terminus, multiple sampling of each laser beam was effected by use of a photo-optical technique that records a 61-cm cross section of an optical beam. Concurrent with the optical data, wind-speed and direction recordings were made at multiple points along the optical path in order to estimate the homogeneity of meteorological conditions. Near the path terminus, measurements of wind shear and temperature lapse were taken. In addition, high-speed-thermometry techniques were utilized to compute one-dimensional temperature spectra as well as the thermal structure coefficient CT. Data were gathered during temperature-lapse, neutral, and inversion conditions. Log-irradiance scans derived from the optical data were used to compute log-irradiance power spectra, variance, and other statistical quantities. From these optical and meteorological data, optical-filter functions were calculated for spatial frequencies above 87 cycles/m and are used for comparison with current theories. The saturation of the log-irradiance data is again observed, and the isotropy of the irradiance fluctuations is examined.
Two new members of the OmpR superfamily detected by homology to a sensor-binding core domain.

The OmpR superfamily includes proteins that act as transcriptional regulators of operons that respond to environmental stimuli. A homologous domain near the N-terminus, termed a sensor-binding core domain, is thought to play a role in recognition of a signal transduction protein. We have identified two previously unrecognized members of this regulator family of proteins: a 23.8-kd protein transcribed from theuvrC transcription unit and the PgtA gene product, which is a phosphoglycerate transport regulatory protein. The sensor-binding core domain is also present in four proteins that regulate bacterial sporulation and chemotaxis. The 23.8-kd protein also has sequence similarity to elongation factor Tu and two regulatory proteins: HtpR, the heat-shock regulatory protein, and TraJ, a regulator of expression of genes involved in conjugation. There is a 77-amino acid region near the C-terminus of the 23.8-kd protein that has 30% similarity with a 28.1-kd protein coded for by an open reading frame 5′ to the reading frame of the 23.8-kd protein in theuvrC transcription unit. Genetic distance analysis of amino acid sequences of proteins with a sensor-binding core domain suggests that the 23.8-kd protein and the chemotaxis regulatory proteins are distantly related to the other regulatory proteins in the OmpR superfamily.
The Effect of Interfacial Viscosity on the Kinetics of Formation of Silver Nanoparticles Using Water-in-Oil Microemulsions as Nanoreactors

Silver nanoparticles were prepared by the method of mixing of two microemulsions having similar chemical composition but different reactants in their respective aqueous core. One microemulsion contains silver nitrate in the aqueous core and other contains sodium borohydride. The silver nanoparticles formed were characterized using UV-Visible absorption spectra and TEM micrographs. Effect of chain length of solvent and addition of Arlacel-20 to the AOT/Heptane, AOT/Decane and AOT/Dodecane microemulsion on particle size and absorption spectra of silver nanoparticles was studied. TEM photographs showed agglomerated and bigger particles in case of pure AOT/dodecane whereas addition of Arlacel-20 showed dispersed and smaller particles. Reaction kinetics was observed for silver nanoparticles using UV-visible spectrophotometer. Silver nanoparticles prepared using pure AOT surfactant showed plasmon band (416 nm) immediately after preparation whereas no absorption band of silver nanoparticles was observed for mixed surfactant microemulsion of AOT and Arlacel 20 for few hours indicating the reaction kinetics is slowed down upon addition of Arlacel-20. Growth rate of silver nanoparticles was plotted by monitoring absorption coefficient ratio (e416/e475) as a function of time. AOT/heptane system showed slower growth rate as compared to AOT/decane and AOT/dodecane and also larger particle size. Presence of Arlacel-20 significantly decreases the growth rate in all three alkanes and this observation can be explained using the concept of rigidity of surfactant film at the oil/water interface. It is proposed that higher the interfacial viscosity, slower is the coalescence rate of nanodroplets in the microemulsion system, and hence slower the growth rate of particles and smaller is the final particle size.
Leadership PAC Formation and Distribution Strategies in the United States Senate

ABSTRACT Fundraising through leadership PACs, or political action committees associated with members of Congress, became increasingly prevalent during the 1990s. Such fundraising has become a critical component of how senators market themselves to colleagues, party leaders, constituents, and journalists. This paper first analyzes what motivates senators to form PACs to test the theory that senators are rational, self-interested actors who use PACs to achieve four major goals: reelection, good public policy, influence within the Senate, and higher office. These goals do not conflict with regard to PAC creation, and results show that creation is influenced by seniority, ideology, electoral margin, leadership candidacy, and presidential candidacy. The article then asks why some senators distribute most PAC funds for their own travel and administrative expenses while others donate primarily to colleagues. Although member goals may conflict, analysis of disbursement patterns indicates a relationship between go...
Interior-point algorithm for quadratically constrained entropy minimization problems

In this paper, we develop an interior point algorithm for quadratically constrained entropy problems. The algorithm uses a variation of Newton's method to follow a central path trajectory in the interior of the feasible set. The primal-dual gap is made less than a given ɛ in at most\(O(|\log \in |\sqrt {m + m} )\) steps, wheren is the dimension of the problem andm is the number of quadratic inequality constraints.
Spontaneous calcium transients regulate neuronal plasticity in developing neurons

Calcium ions play critical roles in neuronal differentiation. We have recorded transient, repeated elevations of calcium in embryonic Xenopus spinal neurons over periods of 1 h in vitro and in vivo, confocally imaging fluo 3-loaded cells at 5 s intervals. Calcium spikes and calcium waves are found both in neurons in culture and in the intact spinal cord. Spikes rise rapidly to approximately 400% of baseline fluorescence and have a double exponential decay, whereas waves rise slowly to approximately 200% of baseline fluorescence and decay slowly as well. Imaging of fura 2-loaded neurons indicates that intracellular calcium increases from 50 to 500 nM during spikes. Both spikes and waves are abolished by removal of extracellular calcium. Developmentally, the incidence and frequency of spikes decrease, whereas the incidence and frequency of waves are constant. Spikes are generated by spontaneous calcium-dependent action potentials and also utilize intracellular calcium stores. Waves are produced by a mechanism that does not involve classic voltage-dependent calcium channels. Spikes are required for expression of the transmitter GABA and for potassium channel modulation. Waves in growth cones are likely to regulate neurite extension. The results demonstrate the roles of a novel signaling system in regulating neuronal plasticity, that operates on a time scale 10(4) times slower than that of action potentials.
The Child Care Crisis: Implications for the Growth and Development of the Nation's Children

The child care issue in the U.S. has reached crisis proportions. This article begins by describing the extent and nature of the problem. The 1990 Child Care and Development Act is a step, albeit an imperfect one, toward solving the problem. Several guidelines for developing an effective child care system are articulated. One approach, the School of the 21st Century, is described and preliminary evidence of its effectiveness is presented. Concluding reflections are offered on overcoming barriers in order to establish quality day care services.
Variational path integral simulations using discretized coordinates

Abstract We describe a variational path integral simulation algorithm for quantum Monte Carlo studies of many-body systems in which particles are restricted to occupy sites on a regular simple cubic lattice with lattice constant s , and discuss the algorithm’s potential computational benefits. Application of the algorithm to the weakly bound cluster Ne 3 shows that accurate coordinate-space observables for this system can be computed using lattice constants as large as s = 0.2 a 0 .
‘q-Titration’ of long-chain and short-chain lipids differentiates between structured and mobile residues of membrane proteins studied in bicelles by solution NMR spectroscopy

'q-Titration' refers to the systematic comparison of signal intensities in solution NMR spectra of uniformly (15)N labeled membrane proteins solubilized in micelles and isotropic bicelles as a function of the molar ratios (q) of the long-chain lipids (typically DMPC) to short-chain lipids (typically DHPC). In general, as q increases, the protein resonances broaden and correspondingly have reduced intensities due to the overall slowing of protein reorientation. Since the protein backbone signals do not broaden uniformly, the differences in line widths (and intensities) enable the narrower (more intense) signals associated with mobile residues to be differentiated from the broader (less intense) signals associated with "structured" residues. For membrane proteins with between one and seven trans-membrane helices in isotropic bicelles, we have been able to find a value of q between 0.1 and 1.0 where only signals from mobile residues are observed in the spectra. The signals from the structured residues are broadened so much that they cannot be observed under standard solution NMR conditions. This q value corresponds to the ratio of DMPC:DHPC where the signals from the structured residues are "titrated out" of the spectrum. This q value is unique for each protein. In magnetically aligned bilayers (q>2.5) no signals are observed in solution NMR spectra of membrane proteins because the polypeptides are "immobilized" by their interactions with the phospholipid bilayers on the relevant NMR timescale (∼10(5)Hz). No signals are observed from proteins in liposomes (only long-chain lipids) either. We show that it is feasible to obtain complementary solution NMR and solid-state NMR spectra of the same membrane protein, where signals from the mobile residues are present in the solution NMR spectra, and signals from the structured residues are present in the solid-state NMR spectra. With assigned backbone amide resonances, these data are sufficient to describe major features of the secondary structure and basic topology of the protein. Even in the absence of assignments, this information can be used to help establish optimal experimental conditions.
Beta diversity and the scale‐dependence of the productivity‐diversity relationship: a test in the Californian serpentine flora

Summary 1 The relationship of productivity to species diversity is usually positive at regional scales, but is often neutral, unimodal or negative at local spatial scales. Recent studies have pointed out that beta diversity, or among-locality and within-region variation in species composition, must therefore tend to increase with productivity. 2 We tested for a positive relationship of productivity to beta diversity in herbaceous plants at 105 widely distributed sites on serpentine soil in California. We also asked whether any such pattern could be explained, as previously proposed, by increased environmental heterogeneity at higher levels of productivity. 3 We found that one measure of beta diversity (the species dissimilarity between paired 500 m2 plots on adjacent north and south slopes) was positively related to productivity (as measured by the normalized difference vegetation index, a remotely sensed index). However, this effect was not strong enough to transform the neutral relationship of productivity with alpha (1 m2) diversity to a positive relationship of productivity with gamma (1000 m2) diversity. 4 The positive effect of productivity on beta diversity was not related to increasing heterogeneity in coarse measures of vegetation structure (percentage cover of shade, litter, rocks, moss, bare soil, animal disturbance). We speculate that the effect may instead have a ‘top-down’ explanation: higher beta diversity may be caused by the positive influence of productivity on the size of the regional species pool. 5 Our study illustrates the principle of a ‘scale transition’, in which an ecological pattern is qualitatively different at different spatial scales. Careful attention to scale-dependence may help narrow the search for mechanisms for such long-studied ecological puzzles as the latitudinal diversity gradient.
Disparities in overall survival for male breast cancer patients in the state of Florida (1996-2007)

Abstract Background Little is known regarding population-based disparities in male breast cancer (MBC). We analyzed this for Florida using data from 1996 to 2007. Materials and Methods Data from the Florida Cancer Data System, the Agency for Health Care Administration, and the US Census were linked for MBC patients (n = 1589). Survival time was our primary end point, with adjustments for sociodemographic status, neighborhood-based poverty measures, clinical and hospital characteristics, and comorbidity measures based on linkage with in- and outpatient treatment records. Survival time was modeled using univariate and multivariate Cox regression models. Results Five-year overall survival was 65.7%. Overall mean survival time in years was 7.7, but shorter in black (5.9) than white (7.8) individuals, in non-Hispanic (7.7) than Hispanic (8.5) individuals, and in the lowest socioeconomic status (SES) group (5.9) than in the highest (8.2) SES group. Patients with low SES also presented at a more advanced stage with only 75/175 [42.9%] of low SES patients who presented with localized disease compared with 311/621 [50.1%] for middle-high SES and 162/334 [48.5%] for the highest SES. Univariate hazard regressions found only the highest (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.46-0.85) and middle-high (HR, 0.71; 95% CI, 0.54-0.94) SES were at improved survival compared with lowest SES but this advantage did not remain significant in the fully adjusted model. Marital status, age, smoking status, stage, treatments, and comorbidities were also predictors of survival. Conclusion Survival disparities among SES groups were most apparent in our study. Improved access to screening and health care utilization might attenuate these differences. Understanding other survival disparities can aid in public health and clinical care choices.
Nodose ganglionectomy reduces angiotensin II receptor binding in the rat brainstem

Angiotensin II (Ang II) receptor binding sites in the dorsomedial medulla of intact and unilaterally nodose ganglionectomized rats were identified and characterized using 125I-sarcosine1,isoleucine8 Ang II. This radioligand bound saturably and with high affinity to rat brain homogenates and to sections of rat brainstem. Specific (1 μM angiotensin II displaceable) binding of 125I-sarcosine1,isoleucine8 Ang II was displaced by angiotensin analogues with a potency order similar to that described for angiotensin II receptors. Unilateral nodose ganglionectomy caused a reduction in Ang II receptor binding in the medial solitary tract nucleus, dorsal motor nucleus of the vagus, and area postrema ipsilateral to the lesioned ganglion. This observation suggests that Ang II receptors in the dorsomedial medulla may be located on axon terminals of vagal afferents and cell bodies of vagal efferents.
Quantitative image measurements for outcome analysis of lung nodule treatment

In this study, we designed and implemented a temporal image database for outcome analysis of lung nodules based on spiral CT images. The software package is composed of three parts. They are, respectively, a database management system which stores patient image data and nodule information; a user-friendly graphical user interface which allows a user to interface with the image database; and image processing tools that are designed to segment out lung nodules in the CT image with a simple mouse click anywhere inside a nodule. The image database uses the relational Sybase database system. Patient images and nodule information are stored in separate tables. Software interface has been designed to allow a user to retrieve any patient study from the picture archiving and communication system into the image database.
Tunnel injection GaN/AlN quantum dot UV LED

Light weight and robust ultraviolet (UV) light emitting sources find multitude of uses, for example in water purification, sterilization, bio sensors, solid state lighting and lithography. Direct bandgap III-Nitride semiconductors exhibit bandgap energies extending upto 6.2 eV (210 nm, deep UV). Thus, III-Nitrides are potential candidates for fabricating UV LEDs. But as we move to higher Al compositions to reach shorter wavelengths the internal quantum efficiency (IQE) severely degrades due to factors such as the valence band asymmetry, high threading dislocation densities, quantum confined Stark effect and inefficient n- and p-type doping. To mitigate the adverse effects of such factors and boost the IQE, we propose and demonstrate a new design which incorporates GaN quantum dots (QDs) in AlN barriers and uses tunneling to inject and transfer carriers through the active region.
The Major Field Test in Business: A Direct Measure of Learning in Common Business Disciplines

Assurance of learning and its assessment are critical focal points in collegiate schools of business as programs strive to achieve or maintain Association to Advance Collegiate Schools of Business accreditation. Prior research suggests that student learning in business core disciplines can be measured by the Educational Testing Service Major Field Test in Business (MFT-B). What factors predict student performance on the MFT-B? The authors examined predictors of student learning not addressed in prior research. The analysis of this unique variable set consisting of high school grade point average, grade on an accounting competency exam, cumulative hours earned, and membership in the School of Business Mentor Association furnishes noteworthy, new insight to the understanding of factors that affect learning in business core disciplines.
Use of Contrastive Stress by Preschool Children

Twenty preschool children were asked to describe pairs of pictures, the second of which contrasted with the first in terms of agent, action, or object. The children showed a clear tendency to stres...
Species-dependent degradation of ciprofloxacin in a membrane anodic fenton system.

The anodic Fenton treatment method (AFT) has been successfully applied to the removal of ciprofloxacin (CIP), a widely used fluoroquinolone antibiotic, from aqueous solution. Degradation kinetics were found to be species dependent. At initial pH 3.2, CIP remained in its cationic form and the kinetics followed a previously developed AFT model. At an initial near-neutral pH, CIP speciation changed during the degradation, due to pH changes over the process, and no obvious model fit the data. Density functional theory (DFT) calculations indicated a protonated species-dependent reaction affinity toward hydroxyl radicals. A new model based on the AFT model with the addition of species distribution during the degradation was derived, and it was shown to describe the degradation kinetics successfully. Degradation of reference compounds further confirmed that the free carboxylic acid group, which contributes to the species changes, plays a key role in the observed degradation pattern. Furthermore, degradation of r...
The 2010 Pakistan Flood and Russian Heat Wave: Teleconnection of Hydrometeorological Extremes

In this paper, preliminary results are presented showing that the two record-setting extreme events during 2010 summer (i.e., the Russian heat wave-wildfires and Pakistan flood) were physically connected. It is found that the Russian heat wave was associated with the development of an extraordinarily strong and prolonged extratropical atmospheric blocking event in association with the excitation of a large-scale atmospheric Rossby wave train spanning western Russia, Kazakhstan, and the northwestern China-Tibetan Plateau region. The southward penetration of upper-level vorticity perturbations in the leading trough of the Rossby wave was instrumental in triggering anomalously heavy rain events over northern Pakistan and vicinity in mid- to late July. Also shown are evidences that the Russian heat wave was amplified by a positive feedback through changes in surface energy fluxes between the atmospheric blocking pattern and an underlying extensive land region with below-normal soil moisture. The Pakistan heavy rain events were amplified and sustained by strong anomalous southeasterly flow along the Himalayan foothills and abundant moisture transport from the Bay of Bengal in connection with the northward propagation of the monsoonal intraseasonal oscillation.