cssi/SciSciGPT-SciSciNet huggingface dataset:
Ideal-MHD analysis of the stability of ISX-B high-beta plasmas

Plasmas with volume-averaged beta equal to 3% have been produced in beam-heated ISX-B discharges. Previous modelling of such ISX-B plasmas, at somewhat lower beta and with limited detail as regards plasma shape, has shown that high-n ballooning instabilities should be excited, although none is observed. The authors now use data that allow them to specify free-boundary equilibria, which are influenced by the ISX-B poloidal coil system and iron core, and compare these equilibria with criteria for ideal magnetohydrodynamic (MHD) stability to both low- and high-n number ballooning and kink modes. Both analytic estimates and codes are used in the comparison. It is found that the equilibria studied are predicted to be unstable to both low- and high-n modes, in contrast to the experimental results. Several candidates for resolving these differences are discussed.
Tissue heat transfer in water: lessons from the Korean divers.

ABSTRACT RENNIE, D. W. Tissue heat transfer in water: lessons from the Korean divers. Mecl. Sci. Sports Exerc, Vol. 20, No. 5 (Supplement), pp. S177-S184, 1988. The factors which influence tissue heat transfer and temperature gradients from body core to skin surface are reviewed in the context of studies on Korean diving women. The resistance to heat transfer imposed by resting muscle is shown to be 2-3 times as great as that imposed by overlying fat and skin. However, exercising muscle imposes very little resistance to heat flux because of the increase in convective heat transfer. Accordingly, the limiting resistance to heat flow is shifted to subcutaneous fat and skin during exercise in cold water. Hypothetical examples are given of how important the subcutaneous fat can be in maintaining a high core-towater temperature gradient in cold water and the same validated by examples from the literature. Last, hypothetical examples are given of the role cutaneous blood flow must play in controlling heat flux and temperature gradients across the subcutaneous fat layer.
Safety of Intravenous Thrombolysis within 4.5 h of Symptom Onset in Patients with Negative Post-Treatment Stroke Imaging for Cerebral Infarction

Background Patients with stroke symptoms but negative diffusion-weighted imaging (DWI) might have transient ischemic attacks (TIA) or stroke mimics. Brain DWI is important for the diagnosis of cerebral infarction but it is not available before thrombolysis for most patients to avoid treatment delay. This study aimed to evaluate the safety of IV thrombolysis in patients with a negative post-treatment DWI for cerebral infarction.
A recursive algorithm for evaluating Molodenskii-type truncation error coefficients at altitude

A recursive method is derived for computing the Molodenskii truncation error coefficients at altitude for the altitude-generalized Stokes integral. Furthermore, the Cook truncation error coefficients at altitude corresponding to the generalized Vening-Meinesz integral are derived in terms of the Molodenskii coefficients. Also, the gravity disturbance truncation error coefficients at altitude are related to the Molodenskii coefficients. By combining these results, it is shown how the truncation error for the complete gravity disturbance vector at altitude may be computed recursively.
Prevention of cancer

Abstract Etiology and prevention are not the same. Etiology is a noun, something that is known. Prevention comes from a verb, implying action. There are several steps required between etiology and prevention. There are three levels of prevention which roughly parallel three levels of regulation, being both complementary and interdependent if effective intervention is to be achieved. It is known that cigarette smoking causes cancer, and most agree that nutritional factors are related to some cancer. Intervention in these areas will be achieved by self-motivation, not by regulation. Food additives which are carcinogenic in animals have caused a conflict between presumed risk to humans and perceived benefit by society. Drugs used in cancer treatment offer the clearest intervention area based on risk/benefit assessment. Diagnostic radiation for early detection of breast cancer has been substantially reduced, and radiation exposure to the nonworker population of Three Mile Island was less than the average yearly background. Great potential for the future lies in the application of sophisticated viral techniques to the problems of chemical carcinogens.
Acoustic Doppler velocimetry in aquaculture research: Raceway and quiescent zone hydrodynamics

Solids removal mechanisms in flow-through aquaculture systems generally consist of quiescent settling in a chamber followed by evacuation through a standpipe, vacuuming, filtering, and/or swirl separation. However, these methods are known to be time and labor intensive and are generally inefficient. Prior to attempting to design and model more efficient quiescent zones and solids removal systems, it is necessary to first establish baseline hydraulic operating characteristics in conventional systems. Acoustic Doppler velocimetry (ADV) is a relatively new technology used for the in situ measurement of three-dimensional velocities at discrete locations in flowing fluids, based on the Doppler Principle. In this study, hydrodynamic properties in a raceway system and quiescent zone were characterized using ADV technology and conclusions were developed, which are relevant to future improvements in overall operation and modifications to removal processes in raceways.
Should statisticians reporting to data monitoring committees be independent of the trial sponsor and leadership

It has long been a fundamental principle of clinical trials that interim comparative data should be kept confidential, with such data accessible only to a small number of individuals responsible for its analysis and monitoring. The rationale for keeping investigators and sponsors blinded to interim data has been extensively discussed, but the possible conflicts of interest that could arise for the statistician who performs the analysis of the interim data and presents it to a data monitoring committee has received little attention. We describe these potential conflicts, and the advantages and disadvantages of approaches that might be taken to minimize them. We have invited commentary on this issue from several statisticians with substantial experience in clinical trials and interim data monitoring. Published in 2004 by John Wiley & Sons, Ltd.
Corticotropin-releasing factor signaling and visceral response to stress.

Stress may cause behavioral and/or psychiatric manifestations such as anxiety and depression and also impact on the function of different visceral organs, namely the gastrointestinal and cardiovascular systems. During the past years substantial progress has been made in the understanding of the underlying mechanisms recruited by stressors. Activation of the corticotropin-releasing factor (CRF) signaling system is recognized to be involved in a large number of stress-related behavioral and somatic disorders. This review will outline the present knowledge on the distribution of the CRF system (ligands and receptors) expressed in the brain and peripheral viscera and its relevance in stress-induced alterations of gastrointestinal and cardiovascular functions and the therapeutic potential of CRF1 receptor antagonists.
Nicotine lozenge efficacy in light smokers

Abstract Background : Nicotine replacement therapy (NRT) has been proven to be effective in heterogeneous groups of smokers. However, analyses have not specifically examined efficacy among light smokers (≤15 cigarettes per day). The objective of this study is to assess the efficacy of a nicotine lozenge in light smokers. Methods : We conducted a secondary analysis of a randomized, placebo-controlled clinical trial contrasting active 2 mg nicotine lozenge with placebo, and contrasting light smokers (≤15 cigarettes per day) with moderate–heavy smokers (>15 cigarettes per day). Participants were 917 smokers who smoked their first cigarette >30 min after waking, and were randomized to active ( n = 459) or placebo ( n = 458) lozenge. Biochemically verified continuous abstinence was measured at 6 weeks and 1 year. Results : Nicotine lozenge significantly increased quit rates relative to placebo at 6 weeks (45.7% versus 31.1%; OR = 1.9 [1.3–2.8]) and at 1 year (19.2% versus 10.0%; OR = 2.3 [1.3–4.0]) among light smokers. Efficacy among light smokers did not differ from that among heavier smokers (ps > 0.50). Conclusion : The nicotine lozenge is effective for light smokers.
The enzyme stability of dehydropeptides

Abstract A pentapeptide, Z-Gly-Gly-Phe-Phe-Ala · OH (1b) and the corresponding unsaturated pentapeptide, Z-Gly-Gly-Phe-Δ Z Phe-Ala · OH (1a) , have been synthesized. The saturated compound (1b) was rapidly hydrolyzed by both chymotrypsin and thermolysin to the expected products, but the dehydropeptide was completely unhydrolyzed by either enzyme even after thirty hours. A new method of peptide stabilization to enzymolysis is made available.
Better generalization in IC3

An improved clause generalization procedure for IC3 is presented. Whereas standard generalization extracts a relatively inductive clause from a single state, called a counterexample to induction (CTI), the new procedure also extracts such clauses from other states, called counterexamples to generalization (CTG), that interfere with the primary generalization attempt. The motivation is to enable IC3 to explore states farther from the error states than are CTIs while remaining property-focused. CTGs are strong candidates for being farther but still backward reachable. Significant reductions in the maximum depth reached by IC3's priority queue-directed explicit backward search indicate that this intention is achieved in practice. The effectiveness of the new procedure is established in two independent implementations of IC3, which demonstrate an increase of 17 and 27, respectively, in the number of solved HWMCC benchmarks.
Multiple Attenuation With Multidimensional Prediction-error Filters

Multiple attenuation in complex geology remains a very intensive research area. The proposed technique aims to use the spatial predictability of both the signal (primaries) and noise (multiples), in order to perform the multiple attenuation in the time domain. The spatial predictability is estimated with multidimensional prediction-error filters. These filters are time-variant in order to handle the nonstationarity of the seismic data. Attenuation of surface-related multiples is illustrated with field data from the Gulf of Mexico with 2-D and 3-D filters. The 3-D filters allow the best attenuation result. In particular, 3-D filters seem to cope better with inaccuracies present in the multiple model for short offset and diffracted multiples.
Awareness as a perceptual model of attention

We proposed a theory of consciousness in which the machinery for social perception constructs awareness, and awareness is a perceptual model of the process of attention. One can attribute awareness to others or to oneself. Awareness of X is the brain's perceptual metaphor for the deep attentive processing of X. A set of ten comments on our hypothesis are included in this issue. Each comment raises specific points some of which directly challenge the hypothesis. Here we respond to these specific points and challenges.
Impulsivity and drugs of abuse: a juice-reinforced operant procedure for determining within-session delay discounting functions in rhesus monkeys.

Introduction Impulsivity is a behavioral trait that is thought to contribute to a variety of disorders, including drug abuse. Efficient, sensitive procedures are needed for studying drug effects on impulsivity (e.g., delay discounting) in nonhumans.
An integrated software system for processing, analyzing, and classifying Raman spectra

Abstract Raman spectroscopy is a powerful technique for analyzing various substances, but a significant amount of processing is required to extract useful information from raw spectra. Many research groups develop custom software systems to process spectra, which leads to standard algorithms being repeatedly implemented and novel techniques being difficult to share. This paper presents an integrated software system that processes, analyzes, and classifies Raman spectra. The system is freely available ( http://cares.wayne.edu/rp/ ), open, cross-platform, and extensible, enabling interested parties to utilize and contribute to a common implementation of Raman processing algorithms. A wide variety of useful features are included, such as noise filtering, automated background fluorescence subtraction, principal component analysis, linear discriminant analysis, artificial neural network classification, and support vector machine classification. The system supports customizable groupings of related spectra and is able to retrieve spectra using a searchable database. Everything is executed through a simple graphical user interface. The developed system was used to process two data sets containing different types of spectra. The results demonstrate that the system is capable of fast, accurate processing of Raman spectra. The open system will become even more powerful if other developers are willing to add new and improved features. In addition, it is intended that the freely available system will make Raman spectroscopy more accessible to all researchers and promote progress in the field.
Revascularization for acute myocardial infarction: thrombolytic therapy or angioplasty — still a burning question

Summary This review summarizes the current knowledge based on the optimal initial revascularization strategies for acute myocardial infarction. Although the available randomized clinical trial data strongly supports the benefits of primary angioplasty over thrombolysis, the interpretation of these and other randomized trials fail to account for the wide interindividual differences in broad cohorts of patients. It is essential to explore which specific subsets of patients will benefit from each of these successful strategies. Clearly one size (of treatment) does not fit all.
Corrosion behavior of SiC p /6061 Al metal matrix composites in chloride solutions

The corrosion behavior of silicon carbide particulates-aluminum metal matrix composites was studied in chloride solution by means of electrochemical techniques, scanning electron microscope (SEM), transmission electron microscope (TEM) and optical microscope. The materials under investigation were compocasting processed 6061 Al reinforced with increasing amounts of SiC particulates. Electrochemical tests such as potentiostatic polarization were done in 0.1 kmol·m−3 NaCl solutions that were aerated and deaerated to observe overall corrosion behavior. In addition, pit morphology was observed after immersion tests. It was seen that the pitting potentials did not vary greatly or show definite trends in relation to the amounts of SiCp reinforcement. However, the degree of corrosion increased with increasing SiCp content; probably mainly due to galvanic couple. No intermetallics layer was found at the SiCp/Al interface. Based on pitting potentials of Al-Si alloys, a pitting process around SiC particulate was proposed.
Robust electrical spin injection into a semiconductor heterostructure

We report efficient electrical injection of spin-polarized carriers from a non-lattice-matched magnetic contact into a semiconductor heterostructure. The semimagnetic semiconductor ${\mathrm{Zn}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{Se}$ is used as a spin-injecting contact on a GaAs-based light-emitting diode. Spin-polarized electrons are electrically injected across the II-VI/III-V interface, where they radiatively recombine in a GaAs quantum well and emit circularly polarized light. An analysis of the optical polarization which includes quantum confinement effects yields a lower bound of 50% for the spin injection efficiency.
Clinical Science Scanning Electron Microscopic and Radiographic Correlation of Articular Surface and Supporting Bone of the Mandibular Condyle

Specimens of mandibular condyle from human cadavers were employed for scanning electron microscopic and radiographic observations of the articulating surface and underlying bone. Smooth articular surface supported by smooth bone was most frequently observed. Craters and depressions in the articular surface were associated with resorption of underlying bone. Lateral radiographs proved to be of limited value in detecting defects of this type.
Mitosis—From Molecules to Machine

This paper concerns the mechanism of mitosis. I briefly review the history of mitosis research, emphasizing the role of microscopic observation. The polymerization and depolymerization of microtubules play central roles in both the assembly of the spindle, and in the way it moves chromosomes. I describe recent advances in understanding the dynamic behavior of individual microtubules, and of microtubules attached to kinetochores. The kinetochore is able to hold on to microtubule ends while allowing them to grow and shrink, reactions that can be studied both in living cells and in the test tube. Experiments in which microtubules in living cells are marked and then followed allow us to relate these individual dynamic processes to the overall mechanism of chromosome movement. I end the review by speculating about biochemical mechanisms for producing force on chromosomes in anaphase, and for balancing chromosomes in the center of the metaphase spindle.
Regulating mental energy: Performance units in language production

Abstract One of the classic puzzles of language is posed by the phenomenon of discontinous dependency, in which the form of an element at one point in an utterance depends on the form of a noncontiguous controlling element. How do speakers use the information carried by the controller to implement the correct form of the dependent element? We contrasted two accounts of this process that differ in their assumptions about the organization of language formulation. The serial account, patterned after an augmented-transition-network model of the parsing of discontinuous dependencies, suggests that the controller is held in working memory until the point in the string at which the dependent appears. A second hypothesis, derived from a hierarchical model of language production, predicts that controllers and dependents within the same clause are specified concurrently, even when they are eventually separated in the utterance. Using a procedure to elicit verb-agreement errors in speech, we found that agreement errors were more frequent after phrases than after clauses that separated the verb from its head noun, reversing the direction of a related effect in language comprehension. When length varied, longer phrases led to more errors; longer clauses did not. These results support the hierarchical hypothesis.
Activation parameters for the α cleavage of alkanones and azoalkanes measured by temperature dependence of fluorescence

Abstract The temperature dependence of fluorescence of several alkanones and several azoalkanes has been measured and Arrhenius parameters have been derived from the data. It is shown that the activation energies derived from an Arrhenius treatment refer directly to the rate of reaction from S1 only when reaction is the major pathway for deactivation. When fluorescence and/or intersystem crossing determine the rate of deactivation of S1, fluorescence is generally found to be temperature independent. The previously reported activation energies for α cleavage from S1 are discussed and compared with the values obtained in this work.
Loss of insulin-mediated vasoprotection: early effect of diabetes on pericyte-containing microvessels of the retina.

PURPOSE. Microvascular cell death is a prominent pathologic feature of the retinopathy associated with insulin-deficient diabetes. The aim of this study was to test the hypothesis that reduced insulin action may contribute to microvascular damage in the diabetic retina. METHODS. Microvascular complexes were isolated from retinas of healthy rats and those made insulin deficient by streptozotocin. As a model of ischemia, freshly isolated microvessels were maintained in a glucose-free, low-oxygen solution. Cell viability in pericyte-containing retinal microvessels was assayed by trypan blue dye exclusion. Cleaved caspase-3 immunoreactivity and nuclear morphology were used to detect apoptotic cells. RESULTS. Ischemia significantly increased apoptotic cell death in pericyte-containing microvessels of the normal rat retina. In a dose-dependent (IC50 600 pM) manner, physiological concentrations of insulin markedly decreased ischemic cell death in the retinal microvasculature. This insulin-mediated vasoprotection was prevented by inhibitors of phosphatidylinositol3-OH kinase and extracellular signal‐regulated kinase. Soon after the onset of diabetes, insulin failed to significantly diminish cell death in ischemic retinal microvessels, in contrast to the prosurvival effect of this hormone on nondiabetic microvessels. CONCLUSIONS. Results of this study support the hypothesis that a physiological concentration of insulin exerts a prosurvival effect on ischemic retinal microvessels and that diabetes impairs the ability of insulin to protect against ischemiainduced microvascular cell death. The authors propose that the loss of insulin-mediated vasoprotection may be a previously unappreciated mechanism by which diabetic retinopathy progresses. (Invest Ophthalmol Vis Sci. 2007;48: 2350‐2355) DOI:10.1167/iovs.06-1357
“Model 2”—A personal journey in pursuit of creativity and impact

Abstract Many have expressed concerns with the lack of innovation and creativity in accounting research, and one particular type of research has come to dominate many of the “elite” journals. In this essay, I discuss my efforts to follow a different path than the traditional “top-tier” archival financial accounting research model. Specifically, I describe two different research career models that one can pursue, which I refer to as “Model 1” and “Model 2”. I describe the research development process under Model 2, which begins with a practice question, and contrast it with a possible approach under Model 1, which begins with the acceptable journal outlets. I then discuss some projects and activities during my career that illustrate the Model 2 approach and its benefits. I close with some overall observations about Model 2 and its challenges, as well as the potential for changing the accounting research culture.
Magnetoplasma Oscillations under Anomalous Skin Effect Conditions

The frequency of magnetoplasma oscillations are calculated under anomalous skin effect conditions, $\mathrm{kl}g1$, $k$ being the wave number of the oscillation and $l$ the electron mean free path. In large magnetic fields such that ${\ensuremath{\omega}}_{c}\ensuremath{\tau}\ensuremath{\gg}1$ it is found that for $\mathrm{kl}\ensuremath{\ll}{\ensuremath{\omega}}_{c}\ensuremath{\tau}$ the frequencies are only slightly modified, whereas for $\mathrm{kl}\ensuremath{\gg}{\ensuremath{\omega}}_{c}\ensuremath{\tau}$ the oscillations are so heavily damped as to be unobservable.
Rate-Distortion Analysis of SP and SI Frames

SP and SI frames in the H.264 video coding standard can be used for error resilience, bitstream switching or random access. Despite a widespread interest in these new types of frames, no work so far has investigated, in a systematic way, their rate-distortion efficiency. In this paper, we propose a model for the rate-distortion performance of SI and SP frames. A comparison to experimental results, obtained with our implementation of an SP encoder, recently adopted by JVT, confirms its validity. The model predicts how the relative sizes of SP and SI frames can be traded off. We analyze, both theoretically and experimentally, how this can be used to minimize the transmitted bit-rate when SP frames are used for video streaming with packet losses.
Expression of 9-kDa non-specific lipid transfer protein genes in developing wheat grain is enhanced by high temperatures but not by post-anthesis fertilizer

Abstract A survey of EST databases identified 16 9-kDa non-specific lipid transfer proteins (nsLTPs) expressed in developing grain from the US spring wheat Butte 86. Two of the most abundant sequences encoded nsLTPs similar to proteins identified previously by two-dimensional gel electrophoresis/mass spectrometry (2-DE/MS). Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) was used to examine the expression of these nsLTPs in developing grain or endosperm produced under controlled temperature and fertilizer regimens. Under a moderate (24 °C/17 °C day/night) temperature regimen, transcripts accumulated late in grain development and achieved highest levels as grain reached maximum dry weight. When high temperature regimens (37 °C/28 °C day/night) were imposed from anthesis or 15 days post-anthesis (DPA) until maturity, maximum transcript levels were as much as 9-fold higher. Post-anthesis fertilizer had relatively small effects on transcript levels. Accumulation profiles for 9-kDa nsLTPs generated by 2-DE were consistent with transcript profiles. The nsLTPs increased 2 to 3.5-fold in amount in endosperm in response to high temperatures but showed little change in response to fertilizer. Flour from grain produced under the high temperature regimens also contained greater amounts of nsLTPs. Increases in the levels of nsLTPs in flour as a result of environmental conditions during grain fill may have important implications for flour quality and allergenic potential.
A growth-promoting influence from the mesonephros during limb outgrowth.

Abstract It has been suggested that the mesonephros has a role in normal limb development. This hypothesis was directly tested by removing the mesonephros adjacent to the presumptive limb region of stage 12–18 chick embryos using microsurgery or laser ablation. The experimental manipulation resulted in reduced limb outgrowth on the operated side. The poor limb outgrowth was correlated with either the lack of or the presence of a rudimentary mesonephros on the operated side. Furthermore, the presence of nephric tissue in limb bud organ culture enhanced growth and morphological differentiation of cartilage formed in culture. In vivo, the influence of the mesonephros resulted in significantly higher cell proliferation in the adjoining medial half of the limb mesoderm compared with the lateral half. The removal of the mesonephros adjoining the prospective limb region reduced the number of dividing cells in the medial mesoderm. The higher proliferation in the medial limb mesoderm is significant to limb outgrowth since grafting experiments showed that most of the cells that form the limb are derived from the medial mesoderm. The results suggest that the influence from the mesonephros may provide some signal for limb outgrowth.
The affordable care act and treatment for "substance use disorders:" implications of ending segregated behavioral healthcare.

The Affordable Care Act (2010) and the Mental Health Parity and Addiction Equity Act (2008) are expected to transform substance abuse prevention and treatment in the United States. In this paper, we outline the potential disruption to the existing specialty care delivery system, and describe the opportunities for treatment providers and health services researchers.
WE-C-103-09: Investigation of Demons Deformable Registration-Based Methods to Measure Lung CT Texture Change Over Time

Purpose: To compare three demons registration‐based methods to identify spatially matched regions in serial computed tomography (CT) scans for use in texture analysis. Methods: Two normal thoracic CT scans were collected from 27 patients. Over 1,000 regions of interest (ROIs) were randomly placed in the lungs of each baseline scan. Anatomically matched ROIs in the corresponding follow‐up scan were placed by mapping the baseline scan ROI center pixel to (1) the original follow‐up scan, (2) the follow‐up scan resampled to match the baseline scan voxel size, and (3) the follow‐up scan aligned to the baseline scan through affine registration. Mappings used the vector field obtained through demons deformable registration of each follow‐up scan variant to the baseline scan. 140 texture features were calculated in all ROIs. Feature value differences between paired ROIs were evaluated using Bland‐Altman analysis. For each feature, (1) the mean feature value change and (2) the distance spanned by the 95% limits of agreement were normalized to the mean feature value to obtain, respectively, normalized bias (nBias) and normalized range of agreement (nRoA). Paired Student's t‐tests were used to compare nBias across the three methods and nRoA across the three methods. Results: For 20 features with low variability (nRoA<20%), significant differences in nBias existed among the three methods. For every feature, the lowest nBias was achieved when feature values were calculated on original follow‐up scans. nRoA was not significantly increased, indicating low variability in feature value change. Conclusion: Three methods to facilitate texture analysis of serial CT scans were evaluated. The bias in feature value change between matched ROIs was minimized with original follow‐up scans, using demons deformation to identify corresponding ROIs between scans. This approach could facilitate future measurement of pathologic change between CT scans without necessitating calculation of feature values on deformed scans. This work was supported, in part, by The Coleman Endowment through The University of Chicago Comprehensive Cancer Center, National Science Foundation Research Experience for Undergraduates (NSF REU) Award No. 1062909, and National Institutes of Health (NIH) Grant Nos. S10 RR021039, P30 CA14599, and T32 EB002103‐23.
Early Changes in Myocardial Microcirculation in Asymptomatic Hypercholesterolemic Subjects: As Detected by Perfusion CT

Intramyocardial microvessels show functional changes in early stages of atherosclerosis prior to epicardial coronary artery stenosis. However, clinical CT does not have adequate spatial resolution to resolve the microvessels. To clinically detect changes in the function of the intramyocardial microcirculation, the spatial heterogeneity of the distribution of myocardial perfusion (F) and intramyocardial microcirculatory blood volume (Bv) was determined by perfusion CT. Two human subject groups were studied: (i) a “Control” group (24) with no risk factors nor evidence of coronary artery disease (CAD), and (ii) an “At-Risk” group (24) with hypercholesterolemia, but no evidence of CAD. In the perfusion CT image, a region of interest (ROI) covering the left ventricular myocardium was subdivided into multiple nested ROI (nROI) of equal size and used to compute F and Bv for each nROI. No significant differences between the groups were demonstrable in overall myocardial F, or Bv. The nROI data showed significantly increased spatial heterogeneity in the “At Risk” group when compared to “Control” subjects. This study demonstrates that subresolution distribution at the microcirculatory level can be quantified with myocardial perfusion CT and significant changes in these parameters occur in hypercholesterolemic subjects before they have developed significant changes in conventional perfusion parameters.
Relation of parton distribution functions in the Drell-Yan process to deeply inelastic scattering

Abstract We consider certain parton distribution functions P (x, k T ) that appear in a proposed form of factorization for the Drell-Yan process at measured Q T . We argue that these Drell-Yan parton distribution functions P q / A (x, k T ) are related by a light cone expansion to the distribution functions ƒ q / A (x) measured in deeply inelastic lepton scattering.
Effects of estrogenic (o,p'-DDT; octylphenol) and anti-androgenic (p,p'-DDE) chemicals on indicators of endocrine status in juvenile male summer flounder (Paralichthys dentatus)

Laboratory experiments were conducted with male summer flounder to assess the value of selected measures of endocrine status in fish as indicators of exposure to endocrine-disrupting contaminants. Effects of 1,1,1-trichloro-2-(p-chlorophenyl)-2-(o-chlorophenyl) ethane (o,p'-DDT), octylphenol and 1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p'-DDE) on hepatosomatic and gonadosomatic indices, plasma steroid hormone levels, vitellogenin production, and gonadal development were evaluated in laboratory-raised, juvenile male summer flounder. Flounder were injected twice with test chemical in a coconut oil carrier. Each chemical was tested at three different concentrations. Estrogenic (o,p'-DDT; octylphenol) and anti-androgenic (p,p'-DDE) chemicals were evaluated alone and in combination (octylphenol plus o,p'-DDT or p,p'-DDE). Additionally, some fish were treated with the natural ligand for the estrogen receptor, 17beta-estradiol. Blood and tissues from different fish in each treatment were sampled 4, 6 and 8 weeks after the first injection. Fish exposed to a combination of o,p'-DDT plus octylphenol were also sampled after 15 weeks. In all cases, responses of fish exposed to a test chemical were compared to control fish sampled at the same time. The following significant differences, relative to controls, were observed in at least one sampling time or at least one concentration of chemical. 17beta-Estradiol-treated flounder exhibited decreased gonadosomatic index (GSI), altered hepatosomatic index (HSI), elevated plasma estradiol, reduced plasma testosterone, and high levels of plasma vitellogenin. Fish treated with o,p'-DDT showed lower GSI, no change in HSI or plasma estradiol, depression of plasma testosterone, and induction of vitellogenesis. Octylphenol treatment resulted in lower GSI, no change in HSI, initially increased plasma estradiol and decreased testosterone, and no vitellogenin production. p,p'-DDE treatment did not significantly alter any indicator relative to controls. In experiments using combinations of chemicals, flounder receiving o,p'-DDT plus octylphenol had lower GSI after 8 weeks and elevated plasma estradiol after 15 weeks exposure. Fish treated with p,p'-DDE plus octylphenol for 8 weeks exhibited a significantly lower GSI. Overall, lower GSI and plasma testosterone levels, relative to controls, were consistent indicators of exposure to estrogenic chemicals in juvenile male flounder. No indicators were found that would identify exposure to the mammalian anti-androgen p,p'-DDE.
Recognition and Response to Native and Novel Predators in the Largespring mosquitofish, Gambusia geiseri

The introduction of predator species into new habitats is an increasingly common consequence of human activities, and the persistence of native prey species depends upon their response to these novel predators. In this study, we examined whether the Largespring mosquitofish, Gambusia geiseri exhibited antipredator behavior and/or an elevation of circulating stress hormones (cortisol) to visual and chemical cues from a native predator, a novel predator, or a non-predatory control fish. Prey showed the most pronounced antipredator response to the native predator treatment, by moving away from the stimulus, while the prey showed no significant changes in their vertical or horizontal position in response to the novel or non-predator treatments. We also found no significant difference in water-borne cortisol release rates following any of the treatments. Our results suggest the prey did not recognize and exhibit antipredator behavior to the novel predator, and we infer that this predator species could be detrimental if it expands into the range of this prey species. Further, our study demonstrates prey may not respond to an invasive predator that is phylogenetically, behaviorally, and morphologically dissimilar from the prey species' native predators.
Spatial and temporal resolution of shear in an orbiting petri dish.

It is well documented that physiological and morphological properties of anchored cells are influenced by fluid shear stress. Common orbital shakers provide a means of simultaneously applying shear stress to cells for tens to hundreds of cases by loading the shaker with multiple dishes. However, the complex flow in orbiting dishes is amenable to analytical solution for resolving shear created by the fluid motion only for simplified conditions. The only existing quantification of shear in this flow is an equation that estimates a constant scalar value of shear for the entire surface of the dish. In practice, wall shear stress (WSS) will be oscillatory rather than steady due to the travelling waveform and will vary across the surface of the dish at any instant in time. This article presents a computational model that provides complete spatial and temporal resolution of WSS over the bottom surface of a dish throughout the orbital cycle. The model is reasonably well validated by the analytical solution, with resultant WSS magnitudes that are within 0.99 ± 0.42 dyne/cm2. The model results were compared to tangential WSS magnitudes obtained using one-dimensional optical velocimetry at discreet locations on the bottom of an orbiting dish. The experimental minimum and maximum WSS at 1 mm from the center of the dish were 6 and 7 dyne/cm2, respectively, whereas WSS generated from the computational model ranged from 0.5 to 8.5 dyne/cm2. The experimental minimum and maximum WSS at 12 mm from the center of the dish were 6 and 16 dyne/cm2, respectively, whereas WSS generated from the computational model ranged from 0.5 to 14 dyne/cm2. Discrepancies between the experimental and computational data may be attributed to a sparse sampling rate for the experimental probe, a sharp gradient at the sample area which could cause the unidirectional probe to be inaccurate if its location were not precise, and too few particles to track and a scattering of the signal by the free surface when the liquid is shallow. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Head and neck surgery workforce in the year 2014

The head and neck surgery workforce in the United States over the next 20 years is of significant interest to physicians, patients, and others. Using election to fellowship in the American Society for Head and Neck Surgery or the Society of Head and Neck Surgeons, or both, as the criteria for designation as a head and neck surgeon, a mathematical model was designed to project the growth of the head and neck surgery workforce through the year 2014. The current combined active membership of the two societies was analyzed to determine the impact of age distribution on this model. The paradigm assumes 30 new head and neck surgeons each year and includes the appropriate mortality rate for each cohort. Based on this model, the total number of head and neck surgeons should decrease slightly from 1109 in the year 1994 to 1028 in the year 2014. A steady-state supply of head and neck surgeons is therefore predicted.
Oogenesis in Xenopus laevis (Daudin). I. Stages of oocyte development in laboratory maintained animals.

Oogenesis in the anuran Xenopus laevis can be divided into six stages based on the anatomy of the developing oocyte. Stage I consists of small (50 to 100 μ) colorless oocytes whose cytoplasm is transparent. Their large nuclei and mitochondrial masses are clearly visible in the intact oocyte. Stage II oocytes range up to 450 μ in diameter, and appear white and opaque. Stage I and II are both previtellogenic. Pigment synthesis and yolk accumulation (vitellogenesis) begins during Stage III. Vitellogenesis continues through Stage IV (600 to 1000 μ), the oocytes grow rapidly, and the animal and vegetal hemispheres become differentiated. By Stage V (1000 to 1200 μ) the oocytes have nearly reached their maximum size and yolk accumulation gradually ceases. Stage VI oocytes are characterized by the appearance of an essentially unpigmented equatorial band. They range in size from 1200 to 1300 μ, are postivtellogenic and ready for ovulation. These stages of oocyte development have been correlated with physiological and biochemical data related to oogenesis in Xenopus.
How to Be Proactive About Interference Lessons From Animal Memory

Processes of proactive interference were explored using the pigeon as a model system of memory. This study shows that proactive interference extends back in time at least 16 trials (and as many minutes), revealing a continuum of interference and providing a framework for studying memory. Pigeons were tested in a delayed same/different task containing trial-unique pictures. On interference trials, sample pictures from previous trials reappeared as test pictures on different trials. Proactive-interference functions showed greatest interference from the most recent trial and with the longer of two delays (10 s vs. 1 s). These interference functions are accounted for by a time-estimation model based on signal detection theory. The model predicts that accuracy at test is determined solely by the ratio of the elapsed time since the offset of the current-trial sample to the elapsed time since the offset of the interfering sample. Implications for comparing memory of different species and different types of memor...
Periodicities of solar irradiance and solar activity indices, I

Using a standard FFT time series analysis, our results show an 8–11 months periodicity in the solar total and UV irradiances, 10.7 cm radio flux, Ca-K plage index, and sunspot blocking function. The physical origin of this period is not known, but the evidence in the results exclude the possibility that the observed period is a harmonic due to the FFT transform or detrending. Periods at 150–157 and 51 days are found in those solar data which are related to strong magnetic fields. The 51-day period is the dominant period in the projected areas of developing complex sunspot groups, but it is missing from the old decaying sunspot areas. This evidence suggests that the 51-day period is related to the emergence of new magnetic fields. A strong 13.5-day period is found in the total irradiance and projected areas of developing complex groups. This confirms those results (e.g., Donnelly et al., 1983, 1984; Bai, 1987, 1989) which show that ‘active centers’ are located 180 deg apart from each other.
Complete sequence of IS3

Abstract We have determined the nucleotide sequence of IS3. Our IS3 isolate has 39 bp inverted repeats (IR's) with 6 mismatches, and is 1258 bp long. IS3 contains a large open reading frame (ORF) of 288 codons with a smaller, partially overlapping ORF of 91 codons on the opposite strand in codon-codon register. The large ORF is preceded by and has a 4 bp overlap with a 99 codon ORF that has potential transcriptional and translational start signals. Thus, IS3 could encode a bicistronic mRNA. The Shine-Dalgarno sequence for this 99 codon ORF could be sequestered in a stem-loop structure, but only if the transcript began outside IS3, as was first seen with IS10. This could be a means for preventing fortuitous activation of IS3 by outside promoters. No DNA sequence homology was found between IS3 and other prokaryotic IS elements, but there is slight amino acid sequence homology and significant conservation of hydropathicity patterns between the putative transposases of IS3 and IS2.
Electrostatic Comb Drive Levitation And Control Method

This paper presents the theory, simulation results, and experimental study of the levitating force (normal to the substrate) associated with Interdigitated capacitor (electro static comb) lateral actuators. For compliant suspensions, normal displacements of over 2 /spl mu/m for a comb bias of 30 V are observed. This phenomenon is due to electrostatic attraction induced on top of the suspended structure. By electrically lsolating alternating drive-comb fingers and applying voltages of equal magnitude and opposite sign, levitation force can be reduced by an order of magnitude, while reducing the lateral drive force by less than a factor of 2. The levitation theory incorporates electrostatic simulation results, and agrees well with experimental data.
WebGimm: An integrated web-based platform for cluster analysis, functional analysis, and interactive visualization of results

Cluster analysis methods have been extensively researched, but the adoption of new methods is often hindered by technical barriers in their implementation and use. WebGimm is a free cluster analysis web-service, and an open source general purpose clustering web-server infrastructure designed to facilitate easy deployment of integrated cluster analysis servers based on clustering and functional annotation algorithms implemented in R. Integrated functional analyses and interactive browsing of both, clustering structure and functional annotations provides a complete analytical environment for cluster analysis and interpretation of results. The Java Web Start client-based interface is modeled after the familiar cluster/treeview packages making its use intuitive to a wide array of biomedical researchers. For biomedical researchers, WebGimm provides an avenue to access state of the art clustering procedures. For Bioinformatics methods developers, WebGimm offers a convenient avenue to deploy their newly developed clustering methods. WebGimm server, software and manuals can be freely accessed at http://ClusterAnalysis.org/.
The general pediatrician: projecting future workforce supply and requirements.

Objective. Trends affecting both the supply and requirements of child health physicians call into question earlier assessments about the adequacy of the general pediatric workforce. To understand the ef- fects of these trends over time, we developed a model that projects the national supply of practicing general pediatricians over a 20-year period (2000 -2020). Design. The model incorporates current data on the practicing pediatrician workforce in the United States, pediatric residency graduates entering general pediatrics, and gender- and age-specific measures of productivity and of retirement or death. In addition, it accounts for projected changes in the size and ethnicity of the child population and the proportion of children currently re- ceiving outpatient care from family practitioners. Main Outcome Measures. Time trend of the supply of general pediatricians and the number of children in the population per practicing pediatrician. Results. The baseline model projects that the number of general pediatricians will expand by nearly 25 000 by the year 2020, a 64% increase from the year 2000, whereas the child population is projected to expand by only 9%. The increase was robust to sensitivity analyses measur- ing the impact of each of the model's variables on the future supply of pediatricians. In all probable scenarios, the general pediatrician workforce will expand signifi- cantly more rapidly than the child population. In addi- tion, the trend in pediatrics is in marked contrast to the other primary care specialties. Conclusions. Despite a number of factors that might attenuate the growth of the general pediatrician work- force, none seems sufficient to slow its expansion in relation to the pediatric population. To maintain practice volumes comparable to today, pediatricians of the future may need to provide expanded services to the children currently under their care, expand their patient popula- tion to include young adults, and/or compete for a greater share of children currently cared for by nonpediatricians. Pediatrics 2004;113:435- 442; workforce, child/children, primary care, access, graduate medical education.