cssi/SciSciGPT-SciSciNet huggingface dataset:
Longitudinal variations in MGF-mediated giant motor neuron activity and rapid escape shortening in intact earthworms

Abstract 1. 1. Longitudinal variations in the activity of the segmentally arranged giant motor neuron (GMN1) pathways of the earthworm have been studied using non-invasive electrophysiological recording techniques. 2. 2. When two MGF spikes and their associated GMN1 spikes are closely spaced (e.g. GMN1 interspike interval 4–8 msec), there is a marked increase in the amplitude of the second GMNl-mediated muscle potential. 3. 3. Due to a marked longitudinal gradient, these increases in muscle potential amplitude are greater in anterior than in middle or posterior segments. 4. 4. The large increase in muscle potential amplitude in anterior segments is consistent with the observation that MGF-GMN1-mediated shortening in anterior segments is greater, occurs earlier, and requires fewer antecedent GMN1 spikes than shortening in more posterior segments. 5. 5. The observed longitudinal gradient in motor activity may represent a mechanism for focussing rapid escape withdrawal into anterior segments, which would be most vulnerable to attack when the animal is extended from its burrow.
Studies on rearing Metaphycus helvolus (Hymenoptera: Encyrtidae) for augmentative release against black scale (Homoptera: Coccidae) on citrus in California

Abstract We conducted an evaluation of insectary production of black scale, Saissetia oleae (Olivier), and the encyrtid parasitoid Metaphycus helvolus (Compere) at the Fillmore Insectary in Fillmore, CA. Insectary scale, reared on 3-year-old oleander plants, tended to be smaller on leaves than those on stems and largest on green stems ⩾3 mm in diameter. Many scale were below the optimal size range for parasitization when M. helvolus were first released to “sting” them. The majority of parasitoids (79%) were produced from scale on large green stems. Plants we evaluated produced a mean of 231 female M. helvolus and the sex ratio was near 1:1. When M. helvolus were allowed to oviposit only during discrete 3-day periods (days 0–3, 3–6, 6–9, or 9–12) on 33 day-old scale (at day 0), there were no significant differences in the mean numbers of parasitoid progeny produced among the four treatment periods; however, there appeared to be a trend towards higher production later in the “stinging” process. Female parasitoids emerged from larger scale than male parasitoids. We suggest that insectary production might be improved by delaying the normal “stinging” process until scales are 36 days old. Other methods of reducing per unit parasitoid cost are suggested that might be optimized if alternative methods of rearing black scale could be developed.
Parametrically generated high-efficiency low-frequency oscillations in avalanche diodes

Experimental evidence is presented indicating that the high-efficiency low-frequency oscillation in avalanche diodes is parametrically generated. It is determined that the high efficiency is only observed when the transit time or pump frequency is an integer harmonic of the low-frequency oscillation and extended avalanche is excited.
Statutory damages as a threat to innovation

Considering the negative influence of U.S. statutory damage rules on technology innovation.
Connection between dangling-bond relaxation and metastability in p-type hydrogenated amorphous silicon☆

Transient capacitance experiments on p-type hydrogenated amorphous silicon (a-Si:H) that show a connection between dangling bond relaxation and metastability are described. The data suggest that neutral dangling bonds are reversibly converted into metastable positive charged dangling bonds by hole trapping. These metastable positive dangling bonds reconvert to neutral dangling bonds upon annealing at elevated temperature. The annealing kinetics for this process are the same as those observed for annealing of quenched-in conductivity changes in p-type a-Si:H.
Coordinatively and electronically unsaturated tris(trimethylsilyl)silyl complexes of manganese and iron

Abstract The neutral, bis(silyl) complexes M[Si(SiMe 3 ) 3 ] 2 (THF) n ( 3 , M=Mn, n =2; 4 , M=Fe, n =1) represent reactive, useful starting materials for the synthesis of various silyl derivatives of Mn and Fe. The reaction of 3 with dmpe (dmpe=Me 2 PCH 2 CH 2 PMe 2 ) produced the yellow–orange complex Mn[Si(SiMe 3 ) 3 ] 2 (dmpe), which was characterized by X-ray crystallography as possessing MnSi distances of 2.643(4) and 2.642(3) A. A related benzophenone complex, Mn[Si(SiMe 3 ) 3 ] 2 (OCPh 2 ) 2 , is dark blue in color but possesses neutral ketone ligands (by IR spectroscopy and X-ray crystallography). The reaction of [NEt 4 ]{Fe[Si(SiMe 3 ) 3 ] 2 Cl} with CO gave [NEt 4 ]{Fe(CO) 3 [Si(SiMe 3 ) 3 ] 2 Cl}, and the reaction of 3 with CNXyl (Xyl=2,6-Me 2 C 6 H 3 ) produced Mn[Si(SiMe 3 ) 3 ] 2 (CNXyl)(THF) and the reduced manganese complex (XylNC) 5 MnSi(SiMe 3 ) 3 .
Pro-opiomelanocortin (POMC) deficiency and peripheral melanocortins in obesity.

Melanocortin peptides, derived from pro-opiomelanocortin (POMC), appear to play a significant role in appetite and body weight regulation. Expression of the Pome gene in the central nervous system results in the production of melanocortin peptides, which bind to the melanocortin-4 receptor (MC4-R) and inhibit food intake. MC4-R knockout mice exhibit adult-onset obesity, whereas MC4-R agonists suppress food intake in several models of obesity. Recently, Pome knockout mice were generated and shown to develop hyperphagia and obesity with a time-course and severity comparable to MC4-R knockout mice, whereas daily administration of a stable a-melanocyte stimulating hormone analogue reversed this effect. These data clearly implicate POMC peptides and melanocortin receptors in the pathophysiology of obesity and provide important new tools for their development as therapeutic targets in obesity.
Knowledge acquisition from newspaper stories

Two experiments tested subjects’ acquisition of the information found in newspaper stories. Subjects studied either an actual newspaper story or an altered form of the story constructed by deleting the irrelevant and redundant information and restructuring the remaining information into either a narrative, topical, or outline form. Subjects who studied the intact newspaper story learned little of the irrelevant and redundant information compared to the other information in the story. Presentation of any of the condensed versions of the story led to better recall than presentation of the entire news story. However, none of the structural reorganizations of the text information led to consistently superior recall relative to a passage that deleted the irrelevant information but maintained the news story structure. These results suggest that people may select among several alternative structural schemata for the representation of narrative passages in memory.
System-on-chip design for ultrasonic target detection using split-spectrum processing and neural networks

Ultrasonic detection and characterization of targets concealed by scattering noise is remarkably challenging. In this study, a neural network (NN) coupled to split-spectrum processing (SSP) is examined for target echo visibility enhancement using experimental measurements with input signal-to-noise ratio around 0 dB. The SSP-NN target detection system is trainable and consequently is capable of improving the target-to-clutter ratio by an average of 40 dB. The proposed system is exceptionally robust and outperforms the conventional techniques such as minimum, median, average, geometric mean, and polarity threshold detectors. For realtime imaging applications, a field-programmable gate array (FPGA)-based hardware platform is designed for system-onchip (SoC) realization of the SSP-NN target detection system. This platform is a hardware/software co-design system using parallel and pipelined multiplications and additions for highspeed operation and high computational throughput.
Peptidoglycan fragments elicit antibacterial protein synthesis in larvae of Manduca sexta

In several insect species, serum lysozyme and antibacterial peptide concentration increases after injection of bacteria and other foreign substances. The purpose of this study was to characterize the specificity of this induction in the tobacco hornworm, Manduca sexta. By 48 h after injection of killed bacteria, lysozyme activity was approximately tenfold greater than in untreated insects. This maximal response was observed after injection of every bacterial species tested and after injection of purified cell walls of Micrococcus luteus. A variety of acellular particles, soluble molecules, and bacterial cell wall components were either poor lysozyme inducers or elicited no change in lysozyme concentration. The polysaccharide zymosan from yeast cell walls was a moderate lysozyme inducer. Peptidoglycan from M. luteus cell walls was found to induce lysozyme to a level as great or greater than whole cell walls. Small fragments of peptidoglycan generated by hen egg white lysozyme digestion were isolated, partially characterized, and shown to be good inducers of lysozyme as well as other antibacterial peptides. It appears that peptidoglycan provides a signal that initiates antibacterial responses in the insect.
Building Large Amorphous Polymer Structures: Atomistic Simulation of Glassy Polystyrene

A technique is presented for generating atomistic models of amorphous polymer structures starting from chain configurations on lattice. The method guarantees Gaussian chain statistics and enables control of chain tacticity and monomer sequence while avoiding severe overlaps between the atoms in the structure. We show that the single polymer chain, which completely occupies the lattice with periodic boundary conditions, is Gaussian with chain statistics equivalent to that obtained for a nonreversing random walk on the cubic lattice. The method enables efficient generation of the chain topology, which can then be populated with specific chemical units. Large models of glassy, atactic polystyrene have been generated, and the effects of system size are examined in terms of calculated X-ray scattering intensities. These results demonstrate the efficacy of this new method for generating more realistic polymer glass structures.
A modified cable model for neuron processes with non-constant diameters.

Abstract The neuron axon cable model is expanded and developed to describe the linear subthreshold transmembrane potential of any circular cross section, thin membrane neuron fiber whose radius can be expressed as an analytic function of position, r ( x ). The transmembrane time constant is shown under the condition of space clamp to be independent of changes in geometry. Three typical neuron geometries are modeled (dendrite-soma, soma-axon, and dendrite-soma-axon) and the solutions to the resulting differential equations are numerically evaluated. The geometry-induced effects ate attributed to changes in current density and physiological correlates of the effects are proposed.
A relativistic quantum field theory of finite nuclei

Abstract A relativistic field theory of nuclear matter is applied to finite nuclei in the mean-field Thomas-Fermi approximation Meson masses determine the surface properties. The form factor and spin-orbit interaction are calculated for B = 40. Quantum corrections are investigated.
Survival disparities among African American women with invasive bladder cancer in Florida.

BACKGROUND: The authors sought to understand the effect of patient sex, race, and socioeconomic status (SES) on outcomes for bladder cancer. METHOD: The Florida Cancer Data System and the Agency for Health Care Administration data sets (1998-2003) were merged and queried. Survival outcomes for patients with bladder cancer were compared between different races, ethnicities, and community poverty levels. RESULTS: A total of 31,100 people with bladder cancer were identified. Overall median survival time was 62.7 months. Statistically significantly longer survival times were observed in men (62.8 months vs 62.3 months for women), whites (63.0 months vs 39.6 months for African Americans [AAs], P 15% live in poverty, P < .001). Surgery was associated with dramatically improved survival. AA women diagnosed with bladder cancer were significantly less likely to have endoscopic surgical resection compared with white women (P < .001). On multivariate analysis, independent predictors of poorer outcomes were older age, AA race, female sex, degree of community poverty, histologic tumor grade, advanced tumor stage, and lack of surgical treatment. CONCLUSIONS: Racial and SES disparities in bladder cancer survival were not fully explained by late-stage presentation and undertreatment. Although earlier diagnosis and greater access to surgery would likely yield some improvement in outcomes for AA women, more research is needed to understand the remaining survival gap for this population. Cancer 2009. © 2009 American Cancer Society.
Assessing teen smoking patterns: The weekend phenomenon

Background Adolescent cigarette smokers may have more daily variability in their smoking patterns than adults. A better understanding of teen smoking patterns can inform the development of more effective adolescent smoking cessation interventions.
Management Models and Considerations for Virtual Reference

Our adoption of cutting edge reference services sometimes outpaces our creation of management models capable of supporting them. Sci-tech libraries have been at the forefront of enhancing traditional services with a wide range of virtual reference services to help us meet our patrons' increasing demands for mobility. However, a unique set of practical management considerations are required in order to successfully move from quick setup to full service support.
Selective release of content from microsomal vesicles without membrane disassembly. II. Electrophoretic and immunological characterization of microsomal subfractions.

Rough and smooth microsomes were shown to have similar sets of polypeptide chains except for the proteins of ribosomes bound to the rough endoplasmic reticulum (ER). More than 50 species of polypeptides were detected by acrylamide gel electrophoresis, ranging in molecular weight from 10,000 to approximately 200,000 daltons. The content of rough and smooth microsomes was separated from the membrane vesicles using sublytic concentrations of detergents and differential centrifugation. A specific subset of proteins which consisted of approximately 25 polypeptides was characteristic of the microsomal content. Some of these proteins showed high rates of in vivo incorporation of radioactive leucine or glucosamine, but several others incorporated only low levels of radioactivity within short labeling intervals and appeared to be long-term residents of the lumen of the ER. Seven polypeptides in the content subfractions, including serum albumin, contained almost 50% of the leucine radioactivity incorporated during 5 min and cross-reacted with antiserum against rat serum. Almost all microsomal glycoproteins were at least partly released with the microsomal content. Smooth microsomes contained higher levels of albumin than rough microsomes, but after short times of labeling with [ 3 H]leucine the specific activity of albumin in the latter was higher, supporting the notion that newly synthesized serum proteins are transferred from rough to smooth portions of the ER. On the other hand, after labeling for 30 min with [ 3 H]glucosamine, smooth microsomes contained higher levels of radioactivity than rough microsomes. This would be expected if glycosidation of newly synthesized polypeptides proceeds during their transit through ER cisternae. The labeling pattern of membrane proteins in microsomes obtained from animals which received three daily injections of [ 3 H]leucine, the last administered 1 day before sacrifice, followed the intensity of bands stained with Coomassie blue, with a main radioactive peak corresponding to cytochrome P 450. After the long-term labeling procedure most content proteins had low levels of radioactivity; this was especially true of serum proteins which were highly labeled after 30 min.
The short-distance structure of instantons

Abstract The short-distance structure of a quark propagator in an instanton background field is analyzed. This analysis describes the influence of instantons upon physical processes such as electron-positron annihilation and the deep inelastic scattering of leptons from hadrons.
Crustacean zooplankton community structure in temporary and permanent grassland ponds

Lentic community structure varies across a size gradient of ponds and lakes with physical factors, such as pond drying, and biotic factors, such as fish predation, determining the species assemblage. We studied the effects of pond drying and fish absence on crustacean zooplankton across a gradient of pond sizes in a Texas grassland. We determined the species compositions and size distributions of crustacean zooplankton in 20 temporary and 18 permanent ponds in April after March rains had refilled the ponds. The surface areas of temporary and permanent ponds ranged from <0.01 to 0.21 ha and 0.04 to 13.8 ha, respectively, and temporary ponds were significantly smaller, on average, than permanent ponds. Fish were absent from all temporary ponds and present in all permanent ponds. We detected a difference in the zooplankton species assemblages of the temporary and permanent ponds. Out of 14 total zooplankton taxa that occurred in eight or more ponds, seven taxa were significantly more prevalent in temporary ponds and four taxa were significantly more prevalent in permanent ponds. The sizes of zooplankton in the temporary fishless ponds were greater than those in the permanent ponds with fish present. We concluded that pond size mediated susceptibility to pond drying, and pond drying determined the presence and absence of fish and their secondary trophic-level effect on zooplankton community structure.
Abnormal Structures in Circulating Lymphocytes from Patients with Systemic Lupus Erythematosus and Related Diseases

A prospective electron microscopic study, incorporating blind controls, demonstrated tubuloreticular structures (TRS) in the buffy coat lymphocytes of 32 patients with connective tissue disease. From 1 to 8% of the lymphocyte sections were involved. The abnormal structures consisted of interwoven, electron-dense tubules (220 to 280 A diameter) which were located within the endoplasmic reticulum. Tubuloreticular structures were found in lymphocytes from 20 of 30 patients with systemic lupus erythematosus (SLE), 2 of 4 with discoid lupus erythematosus, 8 of 20 with other connective tissue disease and none of 22 control cases. Clinical evaluation of the patients with SLE disclosed no specific differences between those with TRS-positive or TRS-negative lymphocytes; there were some indications of greater disease activity in the TRS-positive group. The biologic nature of TRS is unknown, but they have been linked to virus infection under both clinical and experimental conditions.
Effect of Micro and Bulk Solvation on the Mechanism of Nucleophilic Substitution at Sulfur in Disulfides

Computational studies of the solution-phase mechanism of nucleophilic substitution at sulfur in disulfides with explicit water representation indicate that the pathway is dependent on the substituent on the sulfur under attack. B3LYP/6-31+G* optimizations for prototype thiolate-disulfide exchange reactions were performed including one to four explicit water molecules, followed by single-point free energy calculations with B3LYP/6-31+G* and the polarized continuum model (PCM). The solution-phase mechanism is the addition−elimination mechanism when the sulfur under attack bears a hydrogen, while the SN2 mechanism is predicted when the sulfur substituent is a methyl group.
RADIATIVE CAPTURE, PARTICLE EMISSION, AND FISSION IN HEAVY NUCLEI

Abstract Cross sections were determined radiochemically following bombardments of 234U, 235U, 236U, 238U and 239Pu with 5–25 MeV deuterons and 237Np with 20–50 MeV helium ions. Although fission accounts for most of the reaction cross section for all target isotopes, products from radiative capture and various spallation reactions were observed. Products corresponding to the (d, γ) reaction were observed from 238U and other uranium isotopes, with a cross section of about 1 mb. Both compound-nucleus and direct-interaction characteristics are apparent in the spallation excitation functions. The uranium (d, 2n), (d, 3n) and (d, 4n) excitation functions show a “mass” effect; that is, the heavier target isotopes have generally higher spallation-product yields. This corresponds to a neutron partial-level width ratio Γn/(Γn+Γt) increasing with N. Results from 239Pu+d and 237Np+α, both of which form the compound system 241Am*, are consistent with the compound nucleus theory, in that (d, 2n) and (d, 3n) excitation functions correlate with (α, 2n) and (α, 3n) excitation functions. Direct interaction features include (d, n) stripping and a prominent (α, αn) reaction in 237Np. Yield curves and fission cross sections have been obtained to characterize the fission reaction.
Predator–prey interactions in river networks: comparing shrimp spatial refugia in two drainage basins

SUMMARY 1. Analysis of drainage networks provides a framework to evaluate the densities and distributions of prey species relative to locations of their predators. Upstream migration by diadromous shrimp (Atya lanipes and Xiphocaris elongata) during their life cycle provides access to headwater refugia from fish predation, which is intense in estuaries and coastal rivers. 2. We postulate that geomorphic barriers (such as large, steep waterfalls >3.5 m in height), can directly limit the distribution of predatory fishes and, indirectly, affect the densities of their prey (freshwater shrimps) in headwater streams. 3. We compared densities of shrimp in pools above and below waterfalls, in four headwater tributaries in two river basins of the Luquillo Mountains of northeastern Puerto Rico. We measured shrimp densities twice a year over 8 years (1998–2005) in Prieta, Toronja, Bisley 3 and Bisley 5 streams, which differ in drainage network positions relative to steep waterfalls in Ro ´o Espo ´ritu Santo and Ro ´o Mameyes. 4. Predatory fishes are absent in the Prieta and Toronja pools and present in Bisely 3 and in lower Bisley 5 pools. Atya lanipes and X. elongata rarely occur in the Bisley streams where predatory fishes are present but these shrimps are abundant in Prieta and Toronja, streams lacking predatory fishes. 5. The mean carapace length of X. elongata is longer in pools where fish are present (Bisley 3 and lower Bisley 5) than in pools lacking fish (Prieta, Toronja, Upper Bisley 5). The increased body size is primarily due to significantly longer rostrums of individuals in stream reaches with fish (below waterfall barriers) than in those reaches lacking fish (above waterfall barriers). Rostrum length may be an adaptation to avoid predation by visually feeding fishes. 6. Atya lanipes and X. elongata distributions and densities were predicted primarily by drainage network position relative to the presence or absence of predatory fishes. High, steep waterfalls effectively impeded fish from moving upstream and created a spatial refuge. Xiphocaris elongata may rely on size refugia (longer rostrum) to minimize predation where spatial refugia are lacking.
Transient wave propagation in bubbly liquids

A theoretical and numerical investigation of the propagation of one-dimensional waves in a bubbly liquid is presented. A variational formulation of the problem is used that yields both the linear-momentum equation and the equation that describes the oscillations of the bubbles. The compressibility of the liquid is taken into account in the formulation. The thermal dissipation is treated by solving the energy-balance equations simultaneously with the mechanical equations. Solutions are obtained by a finite-difference procedure and are compared to the experimental data of Kuznetsov et al. and Noordzij & van Wijngaarden. In some cases quite good agreement is obtained, but in others substantial errors are found. It is suggested that the observed discrepancies may be due to the breakup of the bubbles in the case of very large amplitude disturbances; the fact that the formulation does not include relative motion between the liquid and the bubbles; and possible non-planarity effects in the experiments.
Automatically recognizing intended messages in grouped bar charts

Information graphics (bar charts, line graphs, grouped bar charts, etc.) often appear in popular media such as newspapers and magazines. In most cases, the information graphic is intended to convey a high-level message; this message plays a role in understanding the document but is seldom repeated in the document's text. This paper presents our methodology for recognizing the intended message of a grouped bar chart. We discuss the types of messages communicated in grouped bar charts, the communicative signals that serve as evidence for the message, and the design and evaluation of our implemented system.
Models for Prisoner's Dilemma

Five models of behavior in the Prisoner’s Dilemma are evaluated with respect to two sets of data. Three of the models are relatively adequate in accounting for the observed time courses of outcomes, but are further differentiated by the variances. The “best-fitting” parameters for each model are used to suggest psychological hypotheses about the gross differences observed between male and female populations. The basic methodological problem remains of choosing a model which is accurate enough and at the same time both mathematically tractable and suggestive. Prisoner’s Dilemma is a two-person nonzero-sum game (non-negotiable) with
Myometrial tissue in uterine septa

Abstract Study Objective. To assess the frequency of myometrial tissue in the septa of septate uteri. Design. Retrospective review (Canadian Task Force classification II-2). Setting. University-affiliated tertiary referral center. Patients. Twenty-nine consecutive women with uterine septa diagnosed by magnetic resonance imaging (MRI). Interventions. The MRI examination was performed with a 1.5 Tesla scanner using high-resolution phased array coils with multiplanar fast-spin echo and T1-weighted sequences. Of resected septa, tissue was available in four for histologic evaluation for the presence of myometrial tissue. Measurements and Main Results. In 17 women MRI showed a partial septum, all containing myometrium. The 12 patients with complete septum had evidence of myometrium in the upper part of the septum, with fibrous tissue constituting the lower part. Histology reviewed from four resected septa (2 partial, 2 complete) reported myometrial tissue. Conclusion. Uterine septa are frequently composed of myometrial tissue.
Massive Plasminogen Activator Inhibitor-1 (PAI-1) Upregulation and Suppressed Fibrinolysis Is the Predominant Phenotype in Severely Injured Trauma Patients

METHODS: Prospective observational data were collected from three Level 1 trauma centers from December 2010 to January 2012. Patient demographics, conventional coagulation tests (CCT), rapid thrombelastography (r-TEG) as well as early anatomic, physiologic and radiographic data were assessed to determine independent predictors of MT. MT was defined as 10 units of packed red blood cells transfused over a 24-hour period. Potentially predictive variables were identified by performing univariate analysis (Mann-Whitney U, p < 0.05). Variables were further dichotomized and Chi-square analysis determined significant associations with MT (p<0.05). A backward stepwise conditional logistic regression was performed to determine independent predictors of MT. Area under the receiver operating characteristic curve (AUROC) allowed comparison with previous scoring systems.
Expression, purification, crystallization and preliminary X-ray studies of Vibrio cholerae pseudopilin EpsH.

EpsH is a minor pseudopilin protein of the Vibrio cholerae type II secretion system. A truncated form of EpsH with a C-terminal noncleavable His tag was constructed and expressed in Escherichia coli, purified and crystallized by sitting-drop vapor diffusion. A complete data set was collected to 1.71 A resolution. The crystals belonged to space group P212121, with unit-cell parameters a = 53.39, b = 71.11, c = 84.64 A. There were two protein molecules in the asymmetric unit, which gave a Matthews coefficient V M of 2.1 A3 Da−1, corresponding to 41.5% solvent content.
Trajectories and magnitude of change in coral reef fish populations in Philippine marine reserves: a meta-analysis

Marine reserves are widely implemented worldwide to meet both conservation and fisheries management goals. This study examines the efficacy of Philippine marine reserves using meta-analysis by comparing variations in fish density (1) between reserves and adjacent fished reefs (spatial comparison), (2) within reserves before establishment relative to years following the establishment (temporal comparison), and (3) among reserves classified based on size, age, and enforcement capacity. A grand (total) mean of nineteen 22.3 ha coral reef reserves, protected for a mean duration of 8.2 years, were included in the meta-analyses. The overall density of fishes was higher in the reserves compared with the fished reefs and this difference was largely accounted for by exploited fishes. However, the overall density of fishes within the same reserves remained similar from the period before its establishment to several years following its establishment. Only the density of nonexploited fishes increased significantly during years subsequent to the establishment of the reserves. Neither age nor size of reserves correlated with pattern of change in fish density following the establishment of the reserves; however, fish density was consistently higher in larger and older reserves relative to smaller and younger reserves in the spatial comparison. Furthermore, well-enforced reserves had higher density of exploited fishes relative to less-enforced reserves in both spatial and temporal comparisons. In general, the magnitude and trajectory of change in fish density following the establishment of Philippine marine reserves are influenced by (1) functional groups of fishes under consideration, (2) size and age of the reserve, and (3) level of enforcement of the regulatory mechanisms necessary to sustain a marine reserve.
Accuracy vs. performance in parallel simulation of interconnection networks

Parallel simulation is emerging as the dominant technique for studying parallel computers. However the interconnection networks of these machines can be modeled at many different levels of abstraction, allowing researchers to trade off accuracy and performance. We use the Wisconsin Wind Tunnel, a parallel simulator for cache-coherent shared-memory machines, to study the trade-offs of accuracy versus performance for six different network simulation models. We evaluate these models for a variety of parallel applications, cache-coherence protocols, and topologies. We show that only the two most expensive models-which model contention at individual links-are robust in the presence of high network loads or non-uniform traffic patterns. >
What predicts nurse faculty members' intent to stay in the academic organization? A structural equation model of a national survey of nursing faculty.

Summary Objective To investigate the relations among several factors regarding the academic context within a nationally representative sample of U.S. nursing faculty. Design Correlational design using structural equation modeling to explore the predictive nature of several factors related to the academic organization and the work life of nursing faculty. Setting A survey was used to evaluate several aspects of the work life of U.S. nursing faculty members. Participants Nursing faculty members in academic organizations across the U.S. serving at either CCNE- or NLNAC-accredited institutions of higher education. Methods Standard confirmatory factor analysis was used to assess the validity of a proposed measurement model, and structural equation modeling was used to evaluate the validity of a structural/latent variable model. Results Several direct and indirect effects were observed among the factors under investigation. Of special importance, perceptions of nurse administration's support and perceived teaching expertise positively predicted U.S. nursing faculty members' intent to stay in the academic organization. Conclusions Understanding the way that nursing faculty members' perceptions of the various factors common to the academic context interact with intent to stay in the academic organization is essential for faculty and nursing administrators. This information can assist administrators in obtaining more resources for faculty development to lobby for additional faculty in order to meet the teaching, research, and service missions of the organization; and to personalize relationships with individual faculty members to understand their needs and acknowledge their efforts.
Person-Oriented Versus Technique-Oriented Specialties: Early Preferences and Eventual Choice

Background: Students’ selection of a specialty is an important decision in their career as a physi­cian. While distinguishing primary care physicians from non-primary care specialists has served a purpose for how medicine is practiced and managed, considering alternative ways of grouping specialties is appropriate when exploring specialty decisions. Purpose: This study explored how early specialty preferences correspond to eventual specialty choice using the person-oriented versus technique-oriented taxonomy. Method: Participants were 349 students who completed a career plan survey during the first semes­ter of medical school and later graduated. Results: Chi-square analysis showed a statistically significant difference between students’ early preference for a person-oriented or technique-oriented specialty and the specialty they chose for their residency. Conclusion: Students with an early preference for person-oriented specialties were more likely to choose a person-oriented specialty, whereas students with an early preference for technique-oriented specialties were less likely to enter a technique-oriented specialty. Keywords: career, medical students, specialty
The Role of Methotrexate in the Chemotherapy of Gestational Trophoblastic Neoplasms

The successful use of methotrexate in metastatic choriocarcinoma in 1956 (1) marked a milestone in the history of curative cancer chemotherapy. The survival of patients with widespread disease increased from 10% in the pre-chemotherapy era (2) to 47% in 1961 (3), 74% in 1965 (4), and to about 90% at the present time (5–7). These improvements in survival resulted from improved chemotherapeutic regimens for a disease which presents certain unique features. Methotrexate has played a central role in these regimens, most of the time being the only drug used. The work of centers for the study and treatment of gestational trophoblastic neoplasms, established in the mid-1960s, has also contributed to the more rational use of this drug as new knowledge of clinical pharmacology was developed (8). In this paper, drug treatment for gestational trophoblastic neoplasms is reviewed, with emphasis on the use of methotrexate.
Cysteinyl leukotriene receptors, old and new; implications for asthma

The cysteinyl leukotrienes (cys-LTs) are three structurally similar, but functionally distinct lipid mediators of inflammation. The parent cys-LT, LTC(4) , is synthesized by and released from mast cells, eosinophils, basophils, and macrophages, and is converted to the potent constrictor LTD(4) and the stable metabolite, LTE(4) . While only two cys-LT-selective receptors (CysLTRs) have been identified, cloned, and characterized, studies dating back three decades predicted the existence of at least three functional CysLTRs, each with a characteristic physiological function in airways and other tissues. The recent demonstration that mice lacking both known CysLTRs exhibit full (and in some instances, augmented) physiological responses to cys-LTs verifies the existence of unidentified CysLTRs. Moreover, the ability to manipulate receptor expression in both whole animal and cellular systems reveals that the functions of CysLTRs are controlled at multiple levels, including receptor-receptor interactions. Finally, studies in transgenic mice have uncovered a potentially major role for cys-LTs in controlling the induction of Th(2) responses to common allergens. This review focuses on these recent findings and their potential clinical implications.
The Electrochemical Basis of Odor Transduction in Vertebrate Olfactory Cilia

Most vertebrate olfactory receptor neurons share a common G-protein–coupled pathway for transducing the binding of odorant into depolarization. The depolarization involves 2 currents: an influx of cations (including Ca 2+ ) through cyclic nucleotide-gated channels and a secondary efflux of Cl through Ca 2+ -gated Cl channels. The relation between stimulus strength and receptor current shows positive cooperativity that is attributed to the channel properties. This cooperativity amplifies the responses to sufficiently strong stimuli but reduces sensitivity and dynamic range. The odor response is transient, and prolonged or repeated stimulation causes adaptation and desensitization. At least 10 mechanisms may contribute to termination of the response; several of these result from an increase in intraciliary Ca 2+ . It is not known to what extent regulation of ionic concentrations in the cilium depends on the dendrite and soma. Although many of the major mechanisms have been identified, odor transduction is not well understood at a quantitative level.
Numerical approximation of head and flux covariances in three dimensions using mixed finite elements

Abstract A numerical method is developed for accurately approximating head and flux covariances and cross-covariances in finite two- and three-dimensional domains using the mixed finite element method. The method is useful for determining head and flux covariances for non-stationary flow fields, for example those induced by injection or extraction wells, impermeable subsurface barriers, or non-stationary hydraulic conductivity fields. Because the numerical approximations to the flux covariances are obtained directly from the solution to the coupled problem rather than having to differentiate head covariances, the approximations are in general more accurate than those obtained from conventional finite difference or finite element methods. Results for uniform flow example problems are consistent with results from previously published finite domain analyses and demonstrate that head variances and covariances are quite sensitive to boundary conditions and the size of the bounded domain. Flux variances and covariances are less sensitive to boundary conditions and domain size. Results comparing approximations from lower-order Raviart–Thomas–Nedelec and higher order Brezzi–Douglas–Marini [9] finite element spaces indicate that higher order element space improve the estimate of the flux covariances, but do not significantly affect the estimate of the head covariances.
Structure SNP (StSNP): a web server for mapping and modeling nsSNPs on protein structures with linkage to metabolic pathways

SNPs located within the open reading frame of a gene that result in an alteration in the amino acid sequence of the encoded protein [nonsynonymous SNPs (nsSNPs)] might directly or indirectly affect functionality of the protein, alone or in the interactions in a multi-protein complex, by increasing/decreasing the activity of the metabolic pathway. Understanding the functional consequences of such changes and drawing conclusions about the molecular basis of diseases, involves integrating information from multiple heterogeneous sources including sequence, structure data and pathway relations between proteins. The data from NCBI's SNP database (dbSNP), gene and protein databases from Entrez, protein structures from the PDB and pathway information from KEGG have all been cross referenced into the StSNP web server, in an effort to provide combined integrated, reports about nsSNPs. StSNP provides 'on the fly' comparative modeling of nsSNPs with links to metabolic pathway information, along with real-time visual comparative analysis of the modeled structures using the Friend software application. The use of metabolic pathways in StSNP allows a researcher to examine possible disease-related pathways associated with a particular nsSNP(s), and link the diseases with the current available molecular structure data. The server is publicly available at http://glinka.bio.neu.edu/StSNP/.
Assessment Problems of Whether or Not to Treat Oil Spills

Any decision to treat or not to treat an oil spill with dispersants involves a multiplicity of biological, chemical, physical, and meteorological inputs. Knowledge concerning the fate of treated and untreated spills is a prerequisite for estimating environmental impacts. Biological data concerning acute toxicity levels and the interrelationship of the affected marine biota must be understood and quantified, as well as the weathering of the oil, the modification of it by microorganisms, and the change in the chemical and physical nature of the oil spill by various types of dispersants. Most of the information required to conduct such an assessment is not presently available and must be obtained from a series of laboratory, meso-scale, and in situ types of experiments. The type of information obtainable from each type of experiment is discussed and the role it plays in the assessment process is presented.
Acute effects of rotavirus and malnutrition on intestinal barrier function in neonatal piglets.

CONCLUSION: Overall, malnutrition had no additive effects to rotavirus infection on intestinal barrier function at day 3 post-infection in a neonatal piglet model.
The Etiquette of Observing

The relationship between teacher and students is a highly personal one. For this reason, an observer, particularly an administrative one, can be an invasive presence. The responsibility lies on the observer to minimize this effect by consciously adopting a courteous and non-threatening demeanor.
Phylogeography of striped skunks (Mephitis mephitis) in North America: Pleistocene dispersal and contemporary population structure

Pleistocene climate fluctuations rearranged ecosystems, and influenced the contemporary distribution of modern species. Although specialist species were often restricted to isolated refugia by Pleistocene climate change, generalist species may have been less constrained in their distribution and movements. We used a combination of genetic data and previously published fossil data to investigate the phylogeography and contemporary population structure of a generalist species, the striped skunk (Mephitis mephitis). We sequenced a portion of the mitochondrial cytochrome-b gene (601 base pairs) and amplified 8 microsatellite loci from 314 striped skunk specimens. Phylogenetic analysis of the cytochrome-b gene revealed the presence of 4 distinct phylogroups, and examination of microsatellite data indicated a pattern of secondary contact among these clades. We infer from these data that during the Rancholabrean stage prior to the Illinoian glaciation, striped skunks emerged from a southern refugium in the Texas–Mexico region and colonized the southeastern United States, forming a 2nd, later refugium in the east. This colonization was followed by a 2nd dispersal event from the southern source population to west of the Rocky Mountains during the Illinoian glacial period. During the Sangamonian interglacial stage, 2 distinct subclades formed on either side of the Sierra Nevada. During the Holocene, the subclade that colonized the Great Basin then expanded east across the northern Rockies and recolonized the Great Plains to create an area of secondary contact with the southern phylogroup. Secondary contact occurred to a lesser extent with individuals from the eastern phylogroup east of the Mississippi River. It appears that periodic Pleistocene glacial expansions and retreats caused a series of range expansions and secondary contact events in this native North American species to create a complex pattern of population structure today.
Finite-sample inference with monotone incomplete multivariate normal data, III: Hotelling’s T2-statistic

In the setting of inference with two-step monotone incomplete data drawn from Nd(µ, ), a multivariate normal population with mean µ and covariance matrix , we derive a stochastic representation for the exact distribution of a generalization of Hotelling’s T 2 -statistic, thereby enabling the construction of exact-level ellipsoidal confidence regions for µ. By applying the equivariance of b and b , the maximum likelihood estimators of µ and , respectively, we show that the T 2 -statistic is invariant under ane transformations. Further, as a consequence of the exact stochastic representation, we derive upper and lower bounds for the cumulative distribution function of the T 2 -statistic. We apply these results to construct simultaneous confidence regions for linear combinations of µ, and we apply these results to analyze a data set consisting of cholesterol measurements on a group of Pennsylvania heart-disease patients.
EFFECTS OF ORGANIC CATION STRUCTURE ON BEHAVIOR OF ORGANOBENTONITES

This study quantified the effects of four quaternary ammonium cations (TMA, DTMA, HDTMA, and BTEA) on the mechanical properties of a modified Wyoming bentonite. TMA, DTMA, and HDTMA are organic cations with alkyl chains of lengths 1, 10, and 16 carbons, while BTEA has a benzyl ring attached. Substitution of the organic cations onto the bentonite surfaces altered the soil's behavior by: (1) reducing the soil's specific gravity, with the specific gravity decreasing linearly as the size of the exchanged organic cation was increased; (2) dramatically reducing the soil's liquid limit (from 458% for the unmodified bentonite to 52–65% for the organoclays); (3) reducing the compressibility of the clays (from a compression index of 5.5 for the unmodified bentonite to compression indices of 0.47–0.59 for the organoclays); (4) reducing the swell potential (Cs = ∼1.5 for bentonite compared with 0.035–0.083 for the organoclays); and (5) increasing the direct shear friction angle (7° for unmodified bentonite compared w...
Coupling between cytoplasmic concentration gradients through local control of protein mobility in the Caenorhabditis elegans zygote

Cell polarity is characterized by the asymmetric distribution of factors at the cell cortex and in the cytoplasm. Although mechanisms that establish cortical asymmetries have been characterized, less is known about how persistent cytoplasmic asymmetries are generated. During the asymmetric division of the Caenorhabditis elegans zygote, the PAR proteins orchestrate the segregation of the cytoplasmic RNA-binding proteins MEX-5/6 to the anterior cytoplasm and PIE-1, POS-1, and MEX-1 to the posterior cytoplasm. In this study, we find that MEX-5/6 control the segregation of GFP::PIE-1, GFP::POS-1, and GFP::MEX-1 by locally increasing their mobility in the anterior cytoplasm. Remarkably, PIE-1, POS-1, and MEX-1 form gradients with distinct strengths, which correlates with differences in their responsiveness to MEX-5/6. We show that MEX-5/6 act downstream of the polarity regulators PAR-1 and PAR-3 and in a concentration-dependent manner to increase the mobility of GFP::PIE-1. These findings suggest that the MEX-5/6 concentration gradients are directly coupled to the establishment of posterior-rich PIE-1, POS-1, and MEX-1 concentration gradients via the formation of anterior-fast, posterior-slow mobility gradients.