cssi/SciSciGPT-SciSciNet huggingface dataset:
Predicting success in United States Air Force pilot training using machine learning techniques

Abstract The chronic pilot shortage that has plagued the United States Air Force over the past three years poses a national-level problem that senior military members are working to overcome. Unfortunately, not all pilot candidates successfully complete the necessary training requirements to become fully qualified Air Force pilots, which wastes critical time and resources and only further exacerbates the pilot shortage problem. Therefore, it is important for the Air Force to carefully consider whom they select to attend pilot training. This research examines historical specialized undergraduate pilot training (SUPT) candidate data leveraging a variety of machine learning techniques to obtain insights on candidate success. Computational experimentation is performed to determine how selected machine learning techniques and their respective hyperparameters affect solution quality. Results reveal that the extremely randomized tree machine learning technique can achieve nearly 94% accuracy in predicting candidate success. Additional analysis indicates degree type and commissioning source are the most important features in determining candidate success. Ultimately, this research can inform the modification of future SUPT candidate selection criteria and other related Air Force personnel policies.
Coevolution in the Pleistocene

During the Pleistocene Epoch (2.5 million to 13,000 years ago), hominin culture surpassed genetics as the primary driver of the coevolution of our genus and species. According to Henrich and others, this process began with anatomical changes and better tools that led to cooperation in childcare and hunting, “reverse dominance” in gender relations, and a politics of prestige rather than domination. The middle and late Pleistocene saw the emergence of social norms, stronger bonds of tribalism, egalitarian practices, and the gradual invention of language. Homo sapiens arrived around 300,000 years ago with a “language-ready brain” that facilitated, says Dor, “the systematic instruction of the imagination.” Language increased the power of social norms that, in turn, led to a rise in the size of hunter-gatherer bands, tribalism, migration, and warfare. Ritual practices, which may be traced to our playful proclivities and aptitude for projection, emerged very late in the epoch. Some contemporary rituals, including BaYaka Pygmy rites, may be traced to the Pleistocene. On the basis of Whitehouse’s insights and method of ritual analysis specified in Chapter 2, the initiation rites of adolescent females into womanhood in these tribes may be described as a ritual that begins in dysphoria but eventuates in a euphoric ending. By primarily creating fused identities for the young women, the ritual affirms female solidarity through altruism and also helps to heal the sex and gender divide structured into tribal relations.
Abstract TMP95: A Prospective Quality Initiative to Maximize Dysphagia Screening Prevents Stroke Associated Pneumonia

BACKGROUND AND PURPOSE: Dysphagia can lead to pneumonia and subsequent death following acute stroke. However, no prospective study has demonstrated reduces pneumonia rates after implementation of a dysphagia screen. METHODS: This was a single-center prospective interrupted time series trial of a dysphagia screening quality initiative. Subjects included all ischemic or hemorrhagic strokes over a 42-month period with a 31-month (n=1686) pre-intervention period and an 11-month (n=648) post intervention period. The multifaceted interdepartmental quality improvement initiative centered on a nurse-administered dysphagia screen with rapid speech pathology evaluation. RESULTS: The dysphagia screening initiative increased the percentage of stroke patients screened from 39.3% to 74.2% (p<0.001). Increased screening correlated with a drop in stroke-associated pneumonia from 6.5% to 2.8% (p<0.001). Patients admitted post-initiative had 53% lower odds of pneumonia, after controlling for multiple confounds (OR=0.43, CI...
Effects of administration of N-methyl-D,L-aspartate (NMA) on gonadotropin secretion in untreated and steroid-treated ovariectomized mares during the breeding season and in intact and ovariectomized mares during anestrus.

Abstract The purpose of this experiment was to investigate whether N-methyl-d,L-aspartate stimulated gonadotropin secretion in mares and to determine the response in two experimental paradigms where gonadotropin secretion is low or elevated. In Experiment 1, conducted during the breeding season (summer), eight long-term ovariectomized mares were treated daily for 21 d with progesterone plus estradiol ( n = 4) or oil vehicle. Beginning on Day 14, each mare received, in a randomized design on alternate days, an intravenous injection of either 0, 0.5, 1.0, or 5.0 mg/kg NMA. Treatment with NMA was not accompanied by a change in gonadotropin release in vehicle-treated ovariectomized mares. In steroid-treated mares, gonadotropin values were suppressed compared with vehicle controls, but NMA only induced a significant increase in follicle-stimulating hormone (FSH) and only at the highest dose. In Experiment 2, the effect of the administration of NMA was compared in intact anestrous mares ( n = 4) and long-term ovariectomized mares ( n = 4) during the nonbreeding season. At the highest doses (1.0 and 5.0 mg/kg), NMA induced a significant increase in luteinizing hormone (LH) and FSH in intact mares. In contrast, pretreatment concentrations of LH and FSH were higher in long-term ovariectomized mares and NMA only increased LH, but not FSH, at the highest dose. The results demonstrate that the administration of NMA stimulates the release of LH and FSH in mares. During anestrus, ovarian intact mares appear more responsive than long-term ovariectomized mares. At high doses, NMA may induce differential release of the gonadotropins in long-term ovariectomized mares.
Microsimulation of Urban Development and Location Choices: Design and Implementation of UrbanSim

UrbanSim is a new urban simulation model, developed over the past several years, which is now operational in three urban areas in the United States. The model system is designed to address emerging needs to better coordinate transportation and land use planning as a result of recognition of the strong interactions between land use and transportation, increasing pressure from federal transportation and environmental legislation, and growing adoption of state growth management programs. The model system is implemented as a set of interacting model components that represent the major actors and choices in the urban system, including household moving and residential location, business choices of employment location, and developer choices of locations and types of real estate development, all subject to the influence of governmental transportation and land use policy scenarios. The model design is unusual in the degree of disaggregation of space, time, and agents, and in the adoption of a dynamic disequilibrium approach. The objective of this paper is to describe the entire system at a sufficient level of detail to convey the key specification and design choices made in implementing the system.
Electric-field-induced transformation of incommensurate modulations in antiferroelectric Pb0.99Nb0.02[(Zr1−xSnx)1−yTiy]0.98O3

Most antiferroelectric ceramics are modified from the prototype ${\mathrm{PbZrO}}_{3}$ by adding Sn and Ti in conjunction with small amount of Nb or La to optimize their properties. These modifiers introduce unique nanoscale structural feature to the ceramics in the form of incommensurate modulations. It was shown previously that the modulation is strongly responsive to a change in chemical composition or temperature. However, its response to an electric field, the driving force in real applications, has not been explored before. In the present work the dynamic evolution of the incommensurate modulation during the electric field-induced antiferroelectric-to-ferroelectric transformation was observed with an in situ transmission electron microscopy (TEM) technique. The results indicate that the incommensurate modulation exists as a transverse Pb-cation displacement wave. The wavelength was found to be quite stable against external electrical stimuli, in sharp contrast to the dramatic change under thermal stimuli reported previously. It is suggested that the appeared incommensurate modulation is an average effect of a mixture of two commensurate modulations. The electric field-induced antiferroelectric-to-ferroelectric transformation proceeds with aligning the Pb-cation displacements, which resembles the process of 90\ifmmode^\circ\else\textdegree\fi{} reorientation and 180\ifmmode^\circ\else\textdegree\fi{} reversal in normal ferroelectrics.
Heartfelt crosstalk: desensitization of the GIRK current

Acetylcholine calms the heartbeat by activating Gi-coupled receptors and G-protein-activated inwardly rectifying potassium (GIRK) channels. It also dampens the GIRK current by reducing PIP2 through Gq-coupled receptors. These two types of receptors seem to be engaged in an intriguingly specific form of crosstalk, which leads to desensitization of the GIRK current.
Osteopontin splice variant as a potential marker for metastatic disease in pancreatic adenocarcinoma

Background and Aim Osteopontin (OPN) is a phosphoprotein that activates pathways that induce cancer cell survival and metastasis. Our aim was to examine the expression pattern of OPN splice variants a, b, and c in fine-needle aspirates and to determine their correlation with stage-adjusted pancreatic ductal adenocarcinoma (PDA) survival. Methods Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) was performed in patients with solid pancreatic masses. The tissue was collected and analyzed for the expression of OPN isoforms by reverse transcription–polymerase chain reaction. Survival curves of stages and overexpression of OPN splice variants (a, b, c) were estimated according to the Kaplan–Meier and the log-rank test. Results EUS-FNA was performed in 46 patients with solid pancreatic lesions (40 PDA and 6 chronic pancreatitis). OPNa was highly expressed in 39/40 (98%), OPNb in 24/40 (60%), while OPNc was present in 10/40 (25%) of PDA samples. The median survival was lower in patients whose fine-needle aspiration (FNA) samples expressed OPNb than those without (406 days vs 749 days, P = 0.049). There was no significant difference in survival in patients with OPNc. Cox proportional hazard model demonstrated that OPNb expression had a trend toward decrease overall survival (P = 0.06), with these patients having a hazard of death three times higher than those without. OPNc was found to significantly correlate with metastatic disease (P = 0.009) in PDA patients. Conclusions Our data show for the first time that in FNA samples, there is a strong association between OPNc and presence of metastasis in PDA, and OPNb and poor survival.
Structural and functional analyses of mutant Fur proteins with impaired regulatory function.

Abstract Vibrio anguillarum Fur mutants, 775met9 and 775met11, were characterized. V. anguillarum 775met9 had a change of D to G at position 104 located in the carboxy terminus resulting in impaired Fur activity.Computer analysis predicts perturbation of an alpha-helix in the carboxy terminus which may interfere with Fur protein conformation. Strain 775met11 had a change in the start codon resulting in no protein synthesis. The mutants are unstable, and reversion to the wild type occurs frequently.
Human adipose tissue expansion in pregnancy is impaired in gestational diabetes mellitus

Aims/hypothesis During pregnancy, adipose tissue (AT) must expand to support the growing fetus and the future nutritional needs of the offspring. Limited expandability of AT is associated with insulin resistance, attributed to ectopic lipid deposition. This study aimed to investigate human AT expandability during pregnancy and its role in the pathogenesis of gestational diabetes mellitus (GDM).
Positive Pressure Bronchoscopy Technique: Case Report.

Objective:Foreign body aspiration into the tracheobronchial tree continues to be a challenging problem for otolaryngologists. This is especially true in patients with poor pulmonary reserve.Methods:We describe a novel technique in which an endotracheal sheathed bronchoscope is used as a means to provide positive pressure ventilation simultaneously during foreign body extraction.Results:This new technique afforded the bronchoscopist more time during retrieval of the foreign body where previous attempts were limited by rapid desaturations and the overall nature of the foreign body.Conclusion:The endotracheal sheathed bronchoscope is a safe and efficacious technique for challenging airway foreign bodies complicated by a patient’s limited pulmonary reserve.
Automated Apparel Processing: Computer Simulation of Fabric Deformation for the Design of Equipment

Introduces and evaluates a finite‐element computer model which predicts the bending behaviour of fabric in contact with a surface, in order to optimize the design of equipment used for automated processing of apparel. Describes how simulations were executed for all combinations of eight fabrics and three contact surfaces, and presents the experimental results obtained for similar conditions and fabrics. Proves the validity of the computer model by comparing the experimental results with those obtained by simulation. Describes how the computer model could be used to choose the optimum diameter of a fabric feeder picking roller.
Cenozoic topographic and climatic response to changing tectonic boundary conditions in Western North America

Abstract This study presents an oxygen isotopic record from the Paleocene to the Pliocene based on the analysis of predominantly paleosol carbonate from intermontane basins in southwestern Montana and eastern Idaho. δ 18 O values of calcite decrease by 7 to 10‰ between ∼ 50 and 47 Ma in southwestern Montana and Idaho most likely as a result of an increase in elevation of 2.5 to 3.5 km. This rise in elevation is roughly contemporaneous with the emplacement of the nearby Challis Volcanics, and the formation of metamorphic core complexes in the hinterland of the Sevier thrust belt. Moreover, when compared to previous oxygen isotopic studies that show oxygen isotopic shifts of similar magnitude occurring later (in the late Eocene to early Oligocene in northeastern Nevada, and late Oligocene to Miocene in southern Nevada), the results of this study add to a growing body of evidence for a spatial and temporal migration of high surface elevations from north to south in the Great Basin of western United States. This surface uplift history supports tectonic models calling for north to south removal of the Farallon slab or delamination of the mantle lithosphere.
Phosphorylation of Frog Photoreceptor Membranes induced by Light

LIGHT induces changes in the visual pigment rhodopsin and its retinaldehyde prosthetic group1 but the specific chemical events which lead to photoreceptor excitation remain obscure. We describe here a phosphorylation reaction initiated by rhodopsin bleaching which may be part of the mechanism linking photon absorption to changes in membrane resistance.
Design alternatives for N-stage WDM optical planar permutation networks

Planar permutation networks are a class of multistage switching networks with no crossover between paths that interconnect switching elements. A well-known class of planar networks is the N−Stage network that provides a good compromise between the crossbar and the Benes network. In this paper, we address the problem of designing cost-effective N-Stage optical planar networks with space-wavelength switching capability. Such networks are used for switching in communication and computing systems that employ Wavelength Division Multiplexing (WDM) technology. We investigate two classes of space-wavelength N-stage planar networks, and for each class, we design a number of switching networks and analyze their hardware complexity. In addition, we propose a new method for designing a class of space-wavelength planar networks with reduced complexity. It is shown that, for F ≤ W (where F is the total number of fibers and W that of wavelengths) the proposed method results in planar networks with an average of 67% reduction in overall cost compared to that of networks based on fixed-range wavelength converters.
Mean-field diffusion-limited aggregation and the Saffman-Taylor problem in three dimensions

Motivated by the connection to diffusion-limited aggregation (DLA), we study the Saffman-Taylor problem in an axisymmetric tube geometry. We find that the surface tension selects an allowed set of finger widths from the continuous set present at zero surface tension, as is expected by analogy with the channel geometry. However, the solution branches merge and disappear in pairs as surface tension is lowered. This behavior was first seen in self-similar solutions for sector-shaped cells in two dimensions, but this is the first occurrence of this effect for steady-state patterns. The implications of our results for DLA and for flow in porous media are discussed.
Studying organizational commitment with the OCQ in the Korean retail context: Its dimensionality and relationships with satisfaction and work outcomes

Abstract A two-stage approach was adopted to study organizational commitment among Korean retail employees. First, both exploratory and confirmatory factor analyses were conducted to examine the dimensionality and psychometric properties of organizational commitment as measured by the Organizational Commitment Questionnaire (OCQ). Two dimensions—affective and continuance—were identified. On that basis, this study empirically tested a model on the relationships among two facets of commitment, three facets of job satisfaction (pay, co-worker, and supervisor), and two work outcomes (effort and propensity-to-leave). The model testing results showed that in the Korean retail setting: (1) satisfaction with pay and satisfaction with supervisor significantly increase both affective commitment and continuance commitment; (2) satisfaction with co-workers positively influences affective commitment but has no significant effect on continuance commitment; and (3) affective commitment increases job effort but decreases...
Programmed methods for printer graphical output

It is frequently desirable to display the results of computation in a graphical form. This is often done through the use of special hardware such as digital X,Y-plotters. Programmed graphical output for standard printers is preferable in several situations: (1) when economic considerations do not justify the expense of special hardware for the purpose, (2) when a combination of graphical output with some other kind, such as explanatory material, is desired, and (3) when some special variety of graphical output is needed which cannot readily be drawn by an analog device.A number of routines have been prepared (primarily by users rather than manufacturers) to convert numerical data into graphical form for printing by output typewriters or line printers. Virtually nothing on this subject has been published, and this report represents an admittedly incomplete attempt to describe this technique and suggest possibilities for its use.
When “Heightened” Means “Lessened”: The Case of HIV Prevention Resources in the United States

The HIV/AIDS epidemic continues to be a major public health concern in the United States. There is a very heavy impact of HIV/AIDS in urban communities; metropolitan statistical areas with populations over 1/2 million account for 84.6% of cumulative AIDS cases through 2005.1 There are also glaring racial/ethnic health disparities in the epidemic. In 33 states that tracked HIV/AIDS diagnoses via named reporting from 2001 to 2005, African Americans accounted for 13% of the population and 50.5% of the new HIV/AIDS diagnoses.2 The Center for Disease Control and Prevention (CDC) has just issued a report entitled, “A Heightened National Response to the HIV/AID Crisis Among African Americans.”3 That report outlines a number of important steps in attempting to address these health disparities. The purpose of this commentary is not to critique the action steps outlined in the report, but rather to focus on the resources available to conduct this “heightened response” campaign.
Reversal of melanocytic malignancy by keratinocytes is an E-cadherin-mediated process overriding β-catenin signaling

Abstract Loss of E-cadherin in melanoma cells frees them from keratinocytes-mediated proliferation and phenotypic control, which can be restored by forced E-cadherin expression. In this study, E-cadherin and its derivatives were introduced into metastatic melanoma line 1205Lu. E-cadherin and E-cadherin-α-catenin fusion protein were functional in mediating cell adhesion, downregulating MCAM4 in coculture, and inhibiting proliferation regardless of β-catenin expression levels and activation status. In contrast, cytoplasmic domain-deleted (E-cadΔCYT) derivative was not able to reverse malignancy. The results indicate that E-cadherin-mediated cell adhesion is required for keratinocyte-mediated control of melanocytic cells, which can override proliferative activity of β-catenin.
A New Approach for Measuring Terrain Profiles

This paper presents a new approach for measuring terrain profiles. The proposed approach uses RGB-D sensors to measure terrain surface relative to the vehicle. Since the RGB-D sensor is an area scanner, a feature matching technique called the grid-based feature-to-map matching technique, developed by the authors, matches objects seen in consecutive images and constructs a terrain profile in a global coordinate system. The RGB-D sensor are mounted inside a box to shield natural light and provide consistent LED lighting. As it constructs a terrain profile by matching scanned data regardless of the vehicle movement, the proposed approach is not affected by the vehicle movement as much as conventional techniques and achieves high accuracy. Preliminary experimental work indicates that the proposed approach could measure terrain profiles in sub-centimeter accuracy of all dimensions. The potential applicability of the proposed approach to the maintenance and inspection of railroads has also been demonstrated.Copyright © 2013 by ASME
Genome analysis with gene expression microarrays

Advances in biochemistry, chemistry and engineering have enabled the development of a new gene expression assay. This 'chip-based' approach utilizes microscopic arrays of cDNAs printed on glass as high-density hybridization targets. Fluorescent probe mixtures derived from total cellular messenger RNA (mRNA) hybridize to cognate elements on the array, allowing accurate measurement of the expression of the corresponding genes. Array densities of > 1,000 cDNAs per cm2 enable quantitative expression monitoring of a large number of genes in a single hybridization. A two-color fluorescence detection scheme allows rapid and simultaneous differential expression analysis of independent biological samples. Mass-produced microarrays provide a new tool for genome expression analysis that may revolutionize genetic dissection, drug discovery and human disease diagnostics.
624 CELLULAR CHANGES IN RATS MADE IRON DEFICIENT IN UTERO AND DURING WEANING PERIODS

A total of 120 Sprague-Dawley rats were divided into 3 groups. Group A was born to normal mothers (NM) and suckled on iron deficient anemic mothers (AM) until 21 days of age. This group was subdivided into Group A1 fed an iron deficient diet until 49 days of age and then given IM iron plus an iron sufficient diet (ISD) and Group A2 given IM iron plus ISD from 21 days. Group B was born to AM and suckled on NM and thereafter fed an ISD and Group C, born to and suckled on NM and thereafter fed on ISD. At birth pups of AM (Group B) had significantly lower body weight, hemoglobin (Hb); brain DNA; spleen weight, DNA, protein and iron compared to pups of NM (Group C). At 21 days, Group A2 had significantly lower body weight, Hb, serum iron, brain weight and iron; liver weight, DNA, RNA, protein and iron; spleen weight, DNA, RNA, protein and iron; kidney weight, RNA and iron compared to Group C. There was no significant difference between Group B and C. At 49 days, Group A1 had significantly lower body weight, Hb; serum iron; brain weight, DNA and iron; liver weight, DNA, RNA, protein and iron; spleen RNA and iron; kidney weight, DNA, RNA, protein and iron compared to Group C. At 102 days, no significant differences were observed in any parameters in all groups. Iron deficiency in rats in utero and during weaning periods results in significant cellular changes in brain, liver, spleen and kidney which are corrected by iron administration.
Aryl sulfotransferase IV from rat liver.

Abstract A group of aryl sulfotransferases has been identified that catalyzes sulfate ester formation with simple phenols at an acidic pH and with several physiological metabolites at a more alkaline pH. One enzyme, aryl sulfotransferase IV, has been purified to homogeneity and found to be a protein of 61,000 daltons composed of two subunits of apparent equal size. Homogeneous preparations are active with simple phenols, organic hydroxylamines, and catecholamines as well as serotonin and its metabolites. The enzyme is also active with tyrosine methyl ester and with those peptide hormones e.g., cholecystokinin heptapeptide and some of the enkephalins, which have N-terminal tyrosine residues.
Thermophysical properties of surimi paste at cooking temperature

Thermal conductivity, specific heat and density of Pacific whiting surimi paste with 74, 78, 80 and 84% moisture content were measured and modelled over the cooking temperature range. Thermal conductivity and specific heat were measured using a linear heat source probe and differential scanning calorimetry (DSC), respectively. Both thermal conductivity and specific heat were found to increase with increasing moisture content and temperature. Surimi density was found to decrease with increasing moisture content and temperature. Empirical models, based on quadratic functions of temperature and moisture content, were fitted to the experimental data for each property.
Measurement of the radiative width of the 12.71-MeV level in C 12

The ground-state magnetic dipole transition width of the ${1}^{+}$ level at 12.71 MeV in $^{12}\mathrm{C}$ has been measured to be 0.34\ifmmode\pm\else\textpm\fi{}0.05 eV. This value is used to calculate the total width of the level based on a previous measurement of the relative ground-state $\ensuremath{\gamma}$ width. A total width of 14.6\ifmmode\pm\else\textpm\fi{}2.6 eV is thus calculated. A model-dependent measurement of the isospin mixing between this level and the 15.11-MeV level yields the values $\ensuremath{\beta}=0.19\ifmmode\pm\else\textpm\fi{}0.01$ or 0.05\ifmmode\pm\else\textpm\fi{}0.01.[NUCLEAR REACTION $^{12}\mathrm{C}(e,{e}^{\ensuremath{'}})$ $p=50.5 \frac{\mathrm{MeV}}{c}$; levels measured $\ensuremath{\Gamma}(\ensuremath{\Lambda})$; deduced isospin mixing.]
On the theory of the electrocardiogram

The biophysical basis for understanding the electrocardiogram is set forth. Bioelectric sources arise from electrical activity in the heart at the cellular level. The relation of these sources, which can be formally represented as impressed currents, to potentials involves solution of the volume conductor problem. This solution is based on Green's theorem. Sources are related to the transmembrane action potential through a bidomain model of heart muscle. Microscopic and macroscopic aspects of the bidomain model are developed. Various transformations of the source are considered, including multipoles, multiple dipoles, and replacement of the volume distribution with distributions on the heart surface. Time integrals of the waveform are related to excitation time and action potential duration. The theoretical results form the basis of a computer model of the electrocardiogram that relates skin potentials to the spatial and temporal distribution of action potentials in the heart. >
Predicting Working Memory Failure: A Subjective Bayesian Approach to Model Selection

Abstract We use Bayes factors to compare two alternative characterizations of human working memory load in their ability to predict errors in database query-writing tasks. The first measures working memory load by the number of different features each task contains, while the second attempts instead to measure the complexity of the task by giving more weight to features that require more mental time for their correct execution. We reanalyze data from a previously conducted experiment using two logistic regression models with random subject effects nested within an experimental condition factor. The two models have alternative covariates based on the alternative measures of working memory load. We construct prior distributions based on our subjective knowledge gleaned from related experiments, providing details of the elicitation process. We examine sensitivity of our results to the effects of prior misspecification and case deletion. Asymptotic approximations are used throughout to facilitate computations...
Chemical lonization-mass spectrometric approach to structure determination of an intermediate in bile acid biosynthesis

Abstract In the course of a study on the details of the biosynthesis of cholic acid from cholesterol, 5β-[26,27- 14 C]cholestan-3α,7α,12α,24 S ,25-pentol, an intermediate in the 25-hydroxylation pathway of cholic acid, was incubated for 2 min with the cytosolic fraction of rat liver homogenate in the presence of NAD. A precursor to cholic acid which appeared to be a ketone was isolate from the reaction mixture by thin-layer chromatography. This material proved to be of inadequate volatility for electron impact mass spectrometry and was therefore studied, without further purification, by techniques of chemical ionization mass spectrometry using ammonia as the reagent gas. The spectrum was rerecorded using argon mixed with ammonia to induce additional fragmentation. One of these fragments corresponded to a McLafferty rearrangement of a 24-keto-25-hydroxycholestane derivative. To obtain additional evidence for this structure the following sequence of reactions was conducted on about 20 μg of the intermediate: (1) periodic acid oxidation, (2) diazomethane treatment, and (3) chromic acid oxidation. The change in molecular weight after each reaction agreed with the presence of a 25-hydroxy-24-keto side chain and three secondary hydroxyl groups in the molecule. Therefore, it could be deduced that the intermediate was 3α,7α,12α,25-tetrahydroxy-5β-cholestan-24-one. This work demonstrates that chemical ionization-mass spectrometic techniques can be a labor-saving alternative to other methods of structure determination and that 3α,7α,12α,25-tetrahydroxy-5β-cholestan-24-one is probably an intermediate in the 25-hydroxylation pathway of cholic acid from cholesterol.
Caffeine, selected metabolic gene variants, and risk for neural tube defects.

Background Investigations of maternal caffeine intake and neural tube defects (NTDs) have not considered genetic influences. Caffeine metabolism gene effects were examined in the National Birth Defects Prevention Study.
Infrared spectrum of SeF in solid argon

Abstract Diatomic fluorine was reacted in a low pressure flame with selenium atoms, generated by a microwave discharge in argon seeded with Se 2 , and the products were trapped in solid argon; new infrared absorptions were found at 677.0 and 680.4 cm −1 for 80 Se 19 F and 76 Se 19 F, respectively.
Nanoelectrode arrays for measuring Sympathetic Nervous Activity

This paper reports on the use of arrays of nanoelectrodes to measure activity of the Sympathetic Nervous System. Measurements of the Sympathetic Nervous Activity (SNA) have not been easy; primarily because of poor signal-to-noise ratio (SNR). We report improved SNR of SNA measurements achieved by the use of novel Planar Nanoelectrode Arrays (PNA). Nano scale features on the electrodes provide increased contact area with the host nerve reducing the limiting (Johnson) noise. These electrodes are fabricated using standard CMOS compatible fabrication techniques on a high resistivity silicon substrate and used to measure SNA in test animals. For comparison, traditional wire electrodes were used simultaneously to measure the same signal. The PNAs consistently exhibit significant improvement in the SNR of the measured SNA (35.71 dB vs. 25.08 dB for the wire electrode). Moreover, the PNAs are capable of recording events lost in the noise floor of the wire electrodes.
Palm Oil, Illicit Gin, and the Moral Order of the Ijaw1

THE question of what causes culture to change has frequently centered on the debate between "technologists" and "ideologists." The former impute the major dynamo of cultural change to material and technological developments, which are then followed by adaptations in social organization and, finally, in ideology. The latter see the ideological current-values, beliefs, attitudes-as the fount of change. Redfield placed himself on the side of the ideologists. Referring to Ogburn and to Childe as proponents of an interpretation of history that holds "ideology as chiefly more or less adaptive to the technical (economic) order," Redfield believed, "it is the role of ideas in history which demands consideration in revising the more materialist interpretation of the broad outlines of human history" (1953:75-6). Redfield, however, was not concerned only with ideology and technology per se. He used both of these terms to express what he called a basic difference in the "nature of the bonds among men" (1953: 20), the difference between the moral order and the technical order. The moral order was defined as "the or-
Enteropeptidase levels in duodenal juice of normal subjects and patients with gastrointestinal disease.

Enteropeptidase, trypsin, and chymotrypsin activity in basal and secretin-stimulated duodenal juice of 20 normal adult volunteers and 15 patients with gastrointestinal disease were determined. All enzyme concentrations showed skew distributions, but fluctuations in the secretin-stimulated juices were less pronounced than in the basal secretions. Secretin administration had no influence on the release of enteropeptidase from human duodenal mucosa, but resulted in a very small increase in secretion of pancreatic enzymes. Six out of seven patients with chronic alcoholic pancreatitis or cancer of the pancreas exhibited highly significant elevations of enteropeptidase in their basal as well as secretinstimulated duodenal juice. It is suggested that raised luminal enteropeptidase activity may be the result of pancreatic insufficiency or elevated blood glucagon concentrations.
Hepatocyte Growth Factor Isoforms in Tissue Repair, Cancer, and Fibrotic Remodeling

Hepatocyte growth factor (HGF), also known as scatter factor (SF), is a pleotropic factor required for normal organ development during embryogenesis. In the adult, basal expression of HGF maintains tissue homeostasis and is up-regulated in response to tissue injury. HGF expression is necessary for the proliferation, migration, and survival of epithelial and endothelial cells involved in tissue repair in a variety of organs, including heart, lung, kidney, liver, brain, and skin. The administration of full length HGF, either as a protein or using exogenous expression methodologies, increases tissue repair in animal models of tissue injury and increases angiogenesis. Full length HGF is comprised of an N-terminal hairpin turn, four kringle domains, and a serine protease-like domain. Several naturally occurring alternatively spliced isoforms of HGF were also identified. The NK1 variant contains the N-terminal hairpin and the first kringle domain, and the NK2 variant extends through the second kringle domain. These alternatively spliced forms of HGF activate the same receptor, MET, but they differ from the full length protein in their cellular activities and their biological functions. Here, we review the species-specific expression of the HGF isoforms, their regulation, the signal transduction pathways they activate, and their biological activities.
Prevention of oral bacterial flora transmission by using mouth-to-mask ventilation during CPR

The Emergency Cardiac Care Committee of the American Heart Association has recently recommended utilizing protective barrier precautions during CPR (1,2). We assessed 17 mask and faceshield resuscitation devices for adequacy of barrier protection. Eight of the devices were faceshields (CPR Microshield, Hygenic, MedCare Mask, Resusci, Samaritan, Sealeasy, Portex); 8 were mask devices (Laerdal, Dyna Med, MTM Emergency Lung Ventilator, MTM Emergency Resuscitator, Res-Q-Flo, Rightway Mouth-to-Mask Resuscitation, Trufit), and one of the devices did not meet the criteria for either faceshield or mask (Lifesaver). All masks were disinfected, applied to the investigator's face as directed by the manufacturers' instructions, and then cultured for oral aerobic bacterial flora on the rescuer side. No mask devices cultured positive for oral aerobic bacterial flora, while 6 of 8 faceshield devices cultured positive for oral aerobic bacterial flora (P less than 0.007). The CPR Microshield and the Portex faceshield were the only devices that did not develop a positive culture. We conclude that all ventilation devices with a one-way valve, except the Sealeasy device, provide adequate barrier type protection from oral aerobic bacterial flora when simulating mouth-to-barrier type protection when performing mouth-to-mouth ventilation.
Monocular pattern alternation: Effects of mean luminance and contrast

Monocular pattern alternation refers to the changes over time in the apparent contrast of the components of a pattern formed by superimposing two sinusoidal gratings. In Experiment 1, alternation rate was measured as a function of the orientation, spatial frequency, and mean luminance of the pattern. Experiment 2 determined pattern alternation rate as a function of orientation, spatial frequency, and contrast. For both experiments, alternation was greater for patterns whose components were horizontal and vertical than for patterns whose components were obliquely oriented. These differences were more pronounced at intermediate than at high and low spatial frequencies. With decreases in mean luminance, there was a decline in both the rate of alternation and the differences in rate due to orientation. There was no significant effect of contrast upon alternation rate. Experiment 3 determined the effects of viewing time upon pattern alternation. For both horizontal-vertical and oblique patterns, the frequency of alternation increased with time up to 100-200 sec and then leveled off. However, the rate of increase with time was greater for horizontal-vertical patterns. These results were discussed in terms of the antagonistic interaction between channels tuned to spatial frequency and orientation.
Recent advances in protoplast culture of horticultural crops: small fruits

Abstract Protoplasts derived from intact leaves or callus cultures of grapevine ( Vitis sp.) have been used to study the rates of photosynthesis, the early products of photosynthetic 14 CO 2 fixation, membrane ultrastructure, cell-wall regeneration and the development of callus cultures for eventual regeneration of protoclones. Protocols for the isolation and culture of grape protoplasts for metabolic studies and for the regeneration of cells from protoplasts are described and current progress, limitations and suggestions for future research are discussed.
CORRECTING A MISCONCEPTION ABOUT EOQ

The author discusses the well known (by faculty) but seldom articulated (to students) mathematical reason that the simple EOQ model can be optimized by equating total, rather than marginal, costs.
Scheduling jobs and maintenance activities on parallel machines

Most machine scheduling models assume that the machines are available all of the time. However, in most realistic situations, machines need to be maintained and hence may become unavailable during certain periods. In this paper, we study the problem of processing a set of n jobs on m parallel machines where each machine must be maintained once during the planning horizon. Our objective is to schedule jobs and maintenance activities so that the total weighted completion time of jobs is minimized. Two cases are studied in this paper. In the first case, there are sufficient resources so that different machines can be maintained simultaneously if necessary. In the second case, only one machine can be maintained at any given time. In this paper, we first show that, even when all jobs have the same weight, both cases of the problem are NP-hard. We then propose branch and bound algorithms based on the column generation approach for solving both cases of the problem. Our algorithms are capable of optimally solving medium sized problems within a reasonable computational time. We note that the general problem where at most j machines, 1 ≤ j ≤ m, can be maintained simultaneously, can be solved similarly by the column generation approach proposed in this paper. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 145–165, 2000
Line sources in absorption spectroscopy

Abstract Hollow-cathode tubes and discharge lamps are studied as spectral sources for absorption spectrophotometry. Comparisons are made of monochromatic versus conventional continuous sources with respect to several experimental parameters, particularly the effect of slitwidth. Working curves are shown to indicate the possible advantages of using line sources for narrow band absorption systems.
Radiobiology of the Sheep Biting Louse (Mallophaga: Trichodectidae)

The LD50 for variously aged eggs of Bovicola ovis (Shrank) exposed to gamma irradiation ranged from 0.34 to 51.23 krad. The eggs were progressively more resistant with increasing age. Treatments also resulted in reduced egg production by subsequent females and malformed testes in subsequent males.
Evidence for the existence of a sexually dimorphic nucleus in the preoptic area of the rat

The volume of an intensely staining component of the preoptic area of the male rat is markedly larger than that of the female. Moreover, its volume in both sexes is altered by perinatal hormone exposure consistent with the view that this brain region undergoes hormone dependent sexual differentiation. The present study was carried out to determine if this sexually dimorphic area of the brain has a greater cell density than that of the surround, and if a unique population or distribution of cells, either within one sex or between males and females, characterized this region. A single coronal paraffin section (10 micrometer) through the approximate center of this sexually dimorphic area in four adult gonadectomized rats of each sex was evaluated systematically. Each cell was labelled as being inside or outside of the sexually dimorphic area. In addition to cell density per unit area the following parameters were evaluated through a closed-circuit video system: cell size, staining intensity, shape, and the presence of processes and of a nucleolus. The presence of a nucleolus was further used to identify neurons within the total population of almost 5000 cells that was evaluated. In both sexes, the sexually dimorphic area was characterized by a significantly increased cell density per unit area compared to that of the surround. On this basis, the term, the Sexually Dimorphic Nucleus of the Preoptic Area (SDN-POA) is proposed, for this region. Moreover, the SDN-POA of the male was characterized by increased neuronal density per unit area. The SDN-POA in the male was also found to contain larger cells and neurons, as determined by direct measurement of their greatest diameter, as well as a greater percentage of cells and neurons rated large on a three-point scale (small, medium, and large). No consistent differences in frequency distribution by stain intensity, shape, or the presence of cell processes were found to characterize the SDN-POA or contribute to the sexual dimorphism. It is concluded that the marked sex difference in the volume of the SDN-POA is due principally to an increase in the male of the total area of higher cell and neuronal density. However, the present results do not eliminate the possibility that more subtle differences in neuronal characteristics may exist in the SDN-POA.
The quasi-static fracture behavior of aluminum alloy 5083

Abstract In this paper the quasi-static fracture behavior of aluminum alloy 5083, which finds wide use as connection elements such as plates, is examined. The kinetics governing the fracture behavior of the alloy is rationalized and discussed in light of the mutually interactive and competitive influences of intrinsic microstructural effects, deformation characteristics and of the matrix and concomitant plasticity at the `localized' level, and stress state.
Comparative aspects of root and root nodule secondary metabolism in alfalfa

Abstract l -phenylalanine ammonia lyase (PAL), indoleacetic acid oxidase (IAA oxidase), O -methyltransferase, peroxidase, total phenolics and total indoles were compared in roots and root nodules of alfalfa. PAL, O -methyl-transferase, total phenolics and total indoles were higher in nodules than in roots. Isolated bacteroids were assayed for O -methyltransferase, PAL, peroxidase and total phenolics, but their levels were either low or not detectable. Nodule leghemoglobin was separated by disc gel electrophoresis and found to have IAA oxidase activity. Phenolics, IAA oxidase and leghemoglobin appear to be interrelated in regulating indole levels in the nodule.
At the Crossroads: Understanding the Challenges and Opportunities for Environmental Stewardship

As the 21st century develops, introspection and reevaluation challenge current understanding of environmental policy. Marc Allen Eisner's Governing the Environment argues that environmental governance through command and control should be modified to allow greater access by business, associa tional, and citizen groups. This is not an easy goal, but Eisner sets out a comprehensive (if not forward think ing) approach to the question of effective environ mental management and policy, both in the United States and in the international arena.
Safety-Catch Linker Strategies for the Production of Radiopharmaceuticals Labeled with Positron-Emitting Isotopes

A novel synthetic stratetegy for compounds labeled with the positron-emitting isotope carbon-11 is described. The use of precursors attached to a solid support via safety-catch linkers allows selective release of radiolabeled material, leaving unreacted precursor attached to the support. Two different linkers demonstrate the application to the preparation of radiolabeled N-alkyl tertiary amines and N-alkylsulfonamides. This technique is expected to lead to more widespread use of positron emission tomography for the in vivo analysis of compound behavior.
Living Cationic Polymerization of p-Chloro-α-methylstyrene and Its Sequential Block Copolymerization with Isobutylene

The homopolymerization of p-chloro-α-methylstyrene (pClαMeSt) and its sequential block copolymerization with isobutylene (IB) initiated by 1,3-dimethyl-1,3-diphenyl-1-chlorobutane (DiαMeSt·HCl) in ...