cssi/SciSciGPT-SciSciNet huggingface dataset:
Evolving online learning: can attention to learning styles make it more personal?

As online education continues its ubiquitous expansion, particularly among large scale educational institutions, forces of economics of scale often drive the development of online courses and the process of their instruction towards homogeneity. This migration towards consistency can easily ignore individual differences between students resulting in ineffective instruction and dissatisfaction with the online learning process. Although the importance of faculty - learner interaction has been highlighted as a key ingredient to online learning satisfaction, learner differences, specifically their learning styles, have not been adequately evaluated to propose instructional methods to accommodate these differences. This report analyzes the experience of faculty and learners in online courses to determine the characteristics of and the appropriate amount of individually focused course interaction based on the articulated desires and characteristics of learners. It evaluates whether providing a higher level of faculty interaction to learners who have learning styles aligned with interpersonal collaboration impacts course satisfaction or performance. Based on this analysis, a process of initial learner evaluation and individually focused communication is proposed to effectively instruct diverse online courses.
Decoupled optimal load flow — A condensed formulation

Abstract A decoupled formulation of the nonlinear optimal load flow problem is presented in which the computer memory requirement is considerably reduced by eliminating the equalities as separate constraints. The problem is decoupled into two nonlinear real and reactive power subproblems to schedule the real and reactive output of generators within their prescribed limits. Security and voltage constraints are included in the problem. A new, simple technique is presented to handle the coupling between the two subproblems and make their sequential solution converge to the solution of the original problem without the necessity of iteration with the AC load flow solution. Successful results on the IEEE 30-bus system are presented.
Wind-diesel microgrid system for remote villages in Kenya

Kenya, like most countries in Sub-Saharan Africa, is faced with the problem of limited electricity access especially in rural areas, which in turn hinders national socioeconomic development. To address this issue, this paper proposes the use of wind-diesel microgrid systems to achieve rural electrification. A power flow model is developed to analyze the reliability of a remote wind-diesel microgrid system as demand grows over a period of time. A remote village in Northern Kenya, which is currently being served by an off grid wind-diesel system is used as a case study. The power flow model is used to investigate how the percentage of wind and diesel energy input to the system due to varying diesel unit sizes and wind capacity affects system reliability as demand increases.
cAMP-stimulated termination of vitellogenesis in Hyalophora cecropia: formation of a diffusion barrier and the loss of patency.

Abstract Activation of cAMP-dependent protein kinase (PKA) by cell-permeable analogs of cAMP causes early and mid-vitellogenic follicles of Hyalophora cecropia to terminate vitellogenin uptake [ Wang and Telfer, 1996 , Insect Biochem. Mol. Biol . 26, 85–94 (1996)]. The response is shown here to entail the formation of an epithelial diffusion barrier. Follicle cells that have been loosely organized to provide intercellular pathways for the movement of vitellogenin to the oocyte surface transform into a tight epithelium within 1–2 h of exposure to PKA activators. The follicle cells can now prevent the escape of Lucifer yellow CH that has been iontophoresed into the space surrounding the oocyte, and the entry of labeled vitellogenin from the medium. As they form this functional equivalent of a tight junction, the follicle cells further reduce the intercellular spaces by enlarging and pressing against each other, and by slowing the secretion of the sulfated glycosaminoglycan matrix that separates them during vitellogenesis. The activation of PKA in early and mid-vitellogenic follicles thus appears to trigger prematurely a set of changes that do not normally occur until the follicle has grown to a length of about 2.0 mm.
Shape from line drawings: beyond Huffman-Clowes labeling

Abstract We reveal two problems with the Haufman-Clowes labeling in the domain of polyhedral objects. First, it sometimes produces physically unrealizable interpretations. Second, many unintuitive interpretations can be derived. We propose modifications based on geometric constraints and a heuristic interpretation rule.
Accuracy of real-time vs. blinded offline diagnosis of neoplastic colorectal polyps using probe-based confocal laser endomicroscopy: a pilot study.

Background and study aims: Probe-based confocal laser endomicroscopy (pCLE) is a new imaging modality that enables histological examination of gastrointestinal mucosa during endoscopic procedures. Most studies have evaluated offline interpretation of pCLE images. In clinical practice, real-time interpretation is necessary to assist decision-making during the procedure. The aim of this pilot study was to compare the accuracy of real-time pCLE diagnosis made during the procedure with that of blinded offline interpretation to provide accuracy estimates that will aid the planning of future studies. Patients and methods: pCLE was performed in patients undergoing screening and surveillance colonoscopy. Once a polyp had been identified, one endoscopist analyzed pCLE images during the procedure and made a provisional “real-time” diagnosis. Saved video recordings were de-identified, randomized, and reviewed “offline” 1 month later by the same endoscopist, who was blinded to the original diagnoses. Results: Images from a total of 154 polyps were recorded (80 neoplastic, 74 non-neoplastic). The overall accuracy of real-time pCLE diagnosis (accuracy 79 %, sensitivity 81 %, specificity 76 %) and offline pCLE diagnosis (83 %, 88 %, and 77 %, respectively) for all 154 polyps were similar. Among polyps Conclusions: These results suggest that real-time and offline interpretations of pCLE images are moderately accurate. Real-time interpretation is slightly less accurate than offline diagnosis, but overall both are comparable. Additionally, there was contrasting accuracy between the two methods for small and large polyps.
Field Guide to Trees

When evaluating the worthiness of field guides to trees, there are several criteria which might be considered; perhaps the first should be geographic coverage. If one is attempting to identify a tree in Iowa, one should not be using a guide covering only trees of the Pacific Slope. Although this may seem obvious, problems can occur in guide selection due to geographically misleading titles. Some guides may imply a geographic coverage which is in fact quite different from the actual coverage.
An End to the Fourth Wave of Terrorism

It is widely believed that the current wave of religiously inspired terrorism will persist for the foreseeable future. Is this necessarily the case? This article asserts that this present wave may be cresting, much like previous waves in the modern history of terrorist violence. Further, the article goes on to forecast not an end to terrorism in general, but the likely emergence of still new manifestations of terrorist violence.
Evaluation of CMAQ O3 and PM2.5 performance using Pacific 2001 measurement data

Abstract Measurement data from the Pacific 2001 air quality field study was used to evaluate the performance of Models-3/CMAQ for the period of 9–20 August in 2001, for a domain centered about Vancouver and the Lower Fraser Valley in British Columbia, Canada. The model predicted O3 concentrations reasonably well with a normalized mean bias (NMB) and normalized mean error (NME) of 13.3% and 51.2% over all measurement sites and hours. It showed an excellent performance in predicting daily O3 peaks with a NMB and NME of −2.2% and 24.3%. The model also did well in predicting the time at which the peaks occurred. The model captured the diurnal variations and spatial distributions of O3 concentrations very well, with some difficulty at locations deep in the valley. Model predictions of PM2.5 concentrations over all sites and hours had a moderate NMB and NME of 30.9% and 66.2%. The model did well in predicting the general temporal trend of PM2.5 concentration levels. However, the high hourly variability in PM2.5 measurements was not possible for the model to capture. In addition, the temporal variations of modelled concentrations change more dramatically than the measured. The model performed poorly in predicting PM sulphate, ammonium, and nitrate concentrations. The extreme over-prediction in nitrate concentrations was partially related to an overabundance of total ammonia in the system. Sensitivity tests of NH3 emission reductions showed that reducing NH3 supply to the system could help reduce the over-predictions of both ammonium and nitrate concentrations, although the model science also needs to be improved. To evaluate the PM organics performance, carbon multiplication factors (CMFs) of 1.4 and 1.9 were applied to an urban site and an urban-to-rural transition site, respectively. The model showed satisfactory performance for PM2.5 organics with a NMB and NME of −6.0% and 50.5%.
The paradoxical effects of diethyldithiocarbamate: comparisons between New Zealand black/white F1 hybrid and Balb/c mice.

Abstract Diethyldithiocarbamate (DTC), an immunomodulative agent suggested to enhance T cells, has been shown to prolong life in autoimmune MRL - lpr lpr mice. In addition to increased survival, MRL - lpr lpr mice treated with DTC displayed a number of changes in expression of cell surface antigens as well as decreased serum autoantibody levels. To determine if DTC treatment would have similar positive effects on another murine model of autoimmune disease, we studied the New Zealand Black/White F1 hybrid ( NZB W ). In addition, the effects of DTC treatment on cell surface antigen expression were compared between the NZB W and a normal murine strain, the Balb c . DTC treatment increased the density of cell surface antigens in the NZB W , but decreased the density of these antigens in the Balb c . Treatment with DTC induced distinct changes in the percentage of cells expressing specific surface antigens that differed between the NZB W and the Balb c . There was no affect on serum anti-DNA and anti-histone antibody levels or on survival in NZB W mice treated with DTC. Therefore, while DTC treatment did not successfully influence the disease course in the NZB W , it did result in specific changes in cell surface antigens. These data demonstrate that DTC is capable of inducing a variety of immunologic changes depending upon the strain treated.
Clustering Based Fast Low-Rank Approximation for Large-Scale Graph

As a fundamental data structure, graph has been widely used in machine learning, data mining, and computer vision. However, graph based analysis with respect to kernel method, spectral clustering and manifold learning can reach time complexity of $O(m^3)$, where $m$ is the data size. In particular, the problem becomes intractable when data is in large-scale. Recently, low-rank matrix approximation draws considerable attentions since it can extract essential parts that are responsible for most actions of the matrix. Nonetheless, the structure information embedded in the massive data is inevitably ignored. In this paper, we argue that vector quantization can better reveal the intrinsic structure of the large-scale data and both intra- and inter-cluster matrices should be taken advantage of to boost the accuracy of low-rank matrix approximation. Considering both inter- and intra-relationships, we can reach a better trade-off on different kinds of graphs. Extensive experiments demonstrate that the proposed framework not only keeps lower time complexity but also performs comparably with the state of the art.
Access Behaviors of Children With Specific Language Impairment

The verbal and nonverbal behaviors used by 5 children with specific language impairment (SLI) to attempt to gain access into established interactions were described and compared with those of chronological-age-mates and language-similar control subjects. Three of the children with SLI were unsuccessful. Two of the children with SLI achieved access but did so without using linguistic forms like those most normal-language children use. All of the children with normal language accessed, and most did so quickly and easily using an orderly and sequential set of indirect behaviors. The findings contribute to social-linguistic characterizations of SLI and clarify specific aspects of access described in the normal-language literature.
Implications of U.S. Health Care Reform for the Rural Elderly

How would health care reform proposals affect the barriers rural elders face in accessing health care? How can nurses facilitate access to health care for the rural elderly?
The indeterminacy of color vision

A critical survey of recent work on the ontological status of colors supports the conclusion that, while some accounts of color can plausibly be dismissed, no single account can yet be endorsed. Among the remaining options are certain forms of color realism according which familiar colors are instantiated by objects in our extra-cranial visual environment. Also still an option is color anti-realism, the view that familiar colors are, at best, biologically adaptive fictions, instantiated nowhere.
Double-quantum filtered rotational-echo double resonance.

Abstract The homonuclear scalar coupling of a directly bonded 13C–13C pair has been used to create a double-quantum filter (DQF) to remove the natural-abundance 13C background in 13C{15N} rotational-echo double-resonance (REDOR) experiments. The DQF scalar and REDOR dipolar evolution periods are coincident which is important for sensitivity in the event of weak 13C–15N dipolar coupling. Calculated and observed 13C{15N} DQF–REDOR dephasings were in agreement for a test sample of mixed recrystallized labeled alanines. Glycine metabolism in a single uniform-15N soybean leaf labeled for 6 min by 13CO2 was measured quantitatively by 13C{15N} DQF–REDOR with no background interferences.
A Memory Management System Optimized for BDMPI's Memory and Execution Model

There is a growing need to perform large computations on small systems, as access to large systems is not widely available and cannot keep up with the scaling of data. BDMPI was recently introduced as a way of achieving this for applications written in MPI. BDMPI allows the efficient execution of standard MPI programs on systems whose aggregate amount of memory is smaller than that required by the computations and significantly outperforms other approaches. In this paper we present a virtual memory subsystem which we implemented as part of the BDMPI runtime. Our new virtual memory subsystem, which we call SBMA, bypasses the operating system virtual memory manager to take advantage of BDMPI's node-level cooperative multi-taking. Benchmarking using a synthetic application shows that for the use cases relevant to BDMPI, the overhead incurred by the BDMPI-SBMA system is amortized such that it performs as fast as explicit data movement by the application developer. Furthermore, we tested SBMA with three different classes of applications and our results show that with no modification to the original MPI program, speedups from 2×--12× over a standard BDMPI implementation can be achieved for the included applications.
Effects of plasma membrane Ca(2+) -ATPase tyrosine phosphorylation on human platelet function.

Summary. Background: The plasma membrane Ca2+-ATPase (PMCA) plays an essential role in maintaining low intracellular Ca2+ ([Ca2+]i) in resting platelets. Earlier studies demonstrated that platelet activation by thrombin results in tyrosine phosphorylation of PMCA, which inhibits pump activity. Objectives: The objective was to determine the functional consequences of PMCA tyrosine phosphorylation. Methods: A decapeptide including the tyrosine phosphorylation site of PMCA and a scrambled version were synthesized and introduced into human platelets using saponin. Fura-2 calcium monitoring and aggregometry were used to characterize the effects of inhibition of tyrosine phosphorylation. Results: Western blot analysis of immunoprecipitates showed that introduction of the inhibitory peptide decreased tyrosine phosphorylation of PMCA by nearly 60% in saponin-permeabilized, thrombin-treated platelets as compared with the scrambled control peptide. Concomitant with inhibition of PMCA tyrosine phosphorylation was a significant decrease in [Ca2+]i during thrombin-mediated platelet activation. The functional consequence of reduced PMCA tyrosine phosphorylation and decreased [Ca2+]i was a significant delay in the onset of thrombin-mediated platelet aggregation. Conclusions: The results demonstrate that PMCA tyrosine phosphorylation regulates [Ca2+]i during platelet activation, which affects downstream events in the activation process. Moreover, PMCA tyrosine phosphorylation and resultant inhibition of PMCA activity produces a positive feedback loop mechanism by enhancing the increase in [Ca2+]i accompanying platelet activation.
Reliability and Convergent Validity of Ideational Flexibility as a Function of Academic Achievement

Recent evidence suggests that ideational flexibility shares a significant amount of variance with ideational fluency, and more importantly, that the unique variance of flexibility is unreliable and invalid in terms of inter-item and intertest correlations. However, these findings have been demonstrated only with nongifted individuals. The present study used partial-correlation procedures to evaluate the unique variance of flexibility in the divergent thinking of 230 gifted and nongifted children. Four groups (quartiles of a distribution of composite achievement test scores) were compared for reliability and convergent validity of their flexibility scores. Results confirmed there were significant differences among the four groups and that the unique variance of flexibility was only reliable and valid for the children in the quartile high in achievement.
c-Raf-mediated Inhibition of Epidermal Growth Factor-stimulated Cell Migration

Epidermal growth factor stimulates migration of a number of cell types, yet the signaling pathways that regulate epidermal growth factor-stimulated migration are poorly defined. In this report, we employ a transient transfection migration assay to assess the role of components of the Ras-mitogen-activated protein (MAP) kinase signaling pathway in epidermal growth factor-stimulated chemotaxis of rat embryo fibroblasts. Expression of dominant negative Ras blocks epidermal growth factor-mediated chemotaxis, while constitutively active Ras has no effect on chemokinesis or chemotaxis. PD98059 and U0126, inhibitors of MAP kinase kinase (MEK) activity, decreased epidermal growth factor-stimulated migration, while kinase-defective MEK1, an inhibitor of MAP kinase activation, enhanced migration. To understand the paradoxical effects of these molecules on epidermal growth factor-induced migration, we examined the role of c-Raf on migration. Expression of either wild type c-Raf or the catalytic domain of c-Raf effectively inhibited epidermal growth factor-stimulated cell migration. We suggest that, whereas Ras activity is necessary to promote epidermal growth factor-stimulated migration, sustained activation of c-Raf may be important in down-regulating migratory signaling pathways triggered by epidermal growth factor receptor activation. Further, activation of c-Raf upon inhibition of the MEK-MAP kinase pathway may contribute to the inhibition of cell migration observed with pharmacological MEK inhibitors.
The Relationship between Preabuse Factors and Psychological Symptomatology in Sexually Abused Girls.

This study investigated the relationship between preabuse factors and psychological symptomatology in sexually abused girls. Ninety-four sexually abused girls, 89 clinical controls, and 75 normal controls comprised the subject population. All subjects were ages 6-12. Preabuse information was obtained with the Developmental, Psychiatric, and Medical History (DPM). Symptom measures included the Children's Depression Inventory (CDI), State-Trait Anxiety Inventory for Children (STAIC), Piers-Harris Children's Self-Concept Scale, and the Child Behavior Checklist (CBCL parent version). Results indicated that the sexually abused and clinical control groups had significantly more prior developmental and psychiatric problems and significantly more past stressors on the DPM than the normal control group. In addition, in examining the sexually abused group only, prior developmental and psychiatric problems were clearly associated with increased behavioral and emotional problems (CBCL), self-reported depressive symptoms (CDI), and lower self-esteem (Piers-Harris). Parallel results were found in the clinical control group, although correlations were higher in the sexual abuse group. Findings are interpreted to support the notion that there are a multitude of variables that may affect the psychological adjustment of sexually abused children, including preabuse and post-abuse factors and the trauma of the abusive experience itself.
Hepatobiliary scintigraphy: Nonvisualization of activity in the area of the gallbladder associated with intestinal activity

A 22-year-old, Mexican-American man presented to the emergency service with a two-day history of intermittent, right-upperquadrant (RUQ) pain and nausea, which began shortly after eating bacon and eggs. His past medical history was unremarkable. On physical examination, RUQ tenderness with a positive Murphy's sign was demonstrated. His laboratory data included: WBC 10,600 (normal 4-11,000/mm3), total bilirubin 1.8 (normal 0.2-1.2 mg/dL), SGOT 25 (normal 5-40 IU/ L), SGPT 20 (normal 5-40 IU/L), and serum amylase 11 (normal 2-20 IU/L). Interpretation of his ultrasonic examination was precluded because of interference by bowel gas. Hepatobiliary scintigraphy was requested upon admission. The patient had been fasting for at least two to three hours prior to the scintigraphic study (Fig 1). Shortly after the imaging studies, he was taken to the operating room. The omentum directly inferior to the gallbladder was cyanotic and swollen. The appendix, gallbladder, common bile duct, and small and large bowel appeared normal. A 6 x 6-cm portion of torsed omentum was removed and sent to surgical pathology: hemorrhagic and acutely inflamed omentum consistent with early infarct. The patient had several possible causes for gallbladder nonvisualization by scintigraphy: premature termination of the study, physiologic distension, nonbiliary inflammatory focus, and a remote possibility of asymptomatic chronic cholecystitis.
Segmentation of follicular regions on H&E slides using a matching filter and active contour model

Follicular Lymphoma (FL) accounts for 20-25% of non-Hodgkin lymphomas in the United States. The first step in follicular lymphoma grading is the identification of follicles. The goal of this paper is to develop a technique to segment follicular regions in H&E stained images. The method is based on a robust active contour model, which is initialized by a seed point selected inside the follicle manually by the user. The novel aspect of this method is the introduction of a matched filter for the flattening of background in the L channel of the Lab color space. The performance of the algorithm was tested by comparing it against the manual segmentations of trained readers using the Zijbendos similarity index. The mean accuracy of the final segmentation compared to the manual ground truth was 0.71 with a standard deviation of 0.12.
Basic principles of spectroscopy, and perfusion weighted imaging

In this course, the physical principles of magnetic resonance (MR) spectroscopy, which detects cerebral metabolites and arterial spin labeling (ALS) magnetic resonance imaging (MRI), which can measure regional brain perfusion, are reviewed. Furthermore, applications of MR spectroscopy and ASL-MRI as they relate to neuroimaging studies in aging, Alzheimer’s disease (AD) and in other types of dementia are discussed. Both techniques are entirely non-invasive, do not require injection of tracers, and can be performed in the same session together with anatomical MRI, providing complementary information to structural brain alterations. In AD, MRS studies consistently revealed diminished concentrations of N-acetylaspartate (NAA), an in-vivo marker of viable neurons, axons, and dendrites as well as increased levels of myo-inositol (MI), a proposed marker for glial activation. More than a dozen MRS studies in various brain disorders, including AD have also reported recovery of diminished NAA after pharmaceutical intervention, suggesting MRS might help assessing therapeutic outcomes in trials of brain dysfunction. ASL-MRI, on the other hand, is a relatively new technique and there have been only a few ASL-MRI studies in aging and dementia. Initial results demonstrated that ASL-MRI reveals a stereotypical regional pattern of cerebral hypoperfusion in AD, similar to the patterns observed with SPECT and PET. Moreover, ASL-MRI showed regional hypoperfusion already in mild cognitively impaired subjects, who are at increased risk for AD, suggesting that early signs of AD before clinical symptoms develop may be detected using ASL-MRI. Further improvements in accuracy and reliability of metabolite and perfusion measurements are expected with high magnetic field applications of MRS and ALS-MRI. However, both techniques also face several obstacles at high magnetic fields. Both benefits and pitfalls of high magnetic field MRS and ASL-MRI will also be discussed.
The experienced "sense" of a virtual community: characteristics and processes

E-commerce strategists advise companies to create virtual communities for their customers. But what does this involve? Research on face-to-face communities identifies the concept of "sense of community:" a characteristic of successful communities distinguished by members' helping behaviors and members' emotional attachment to the community and other members. Does a sense of virtual community exist in online settings, and what does it consist of? Answering these questions is key, if we are to provide guidance to businesses attempting to create virtual communities.The paper explores the concept of sense of virtual community in a newsgroup we call Multiple Sports Newsgroup (MSN). We first demonstrate that MSN does indeed have a sense of virtual community, but that the dimensions of the sense of community in MSN differ somewhat from those reported for physical communities. The nature of these differences is plausibly related to the differences between electronic and face-to-face communication. We next describe the behavioral processes that contribute to the sense of virtual community at MSN-exchanging support, creating identities and making identifications, and the production of trust. Again, these processes are similar to those found in non-virtual communities, but they are related to the challenges of electronic communication. Lastly, we consider the question of how sense of community may come about and discuss the implications for electronic business.
Changes in HIV treatment beliefs and sexual risk behaviors among gay and bisexual men, 1997-2005.

Objective: Beliefs about HIV treatment effectiveness and the impact of HIV treatments on HIV transmission risks were initially related to sexual risk-taking in the late 1990s when multidrug HIV treatments first became available. This study examined changes in beliefs about the effects of HIV treatment for preventing HIV transmission and their association to sexual risk behaviors between the years 1997 and 2005. Design: Anonymous surveys were administered to a convenience sample of gay and bisexual men attending a large community event in Atlanta, Georgia in 1997 (N = 498) and again at the same community event in 2005 (N = 448). Analyses were performed for men living with HIV/AIDS and for men who have not been diagnosed with HIV/AIDS. Main Outcome Measures: Rates of unprotected anal intercourse in the previous 3 months. Results: There were significant increases in high-risk sexual practices that coincided with increased beliefs that HIV treatments can reduce the chance of transmitting HIV. However, optimistic beliefs about the health benefits of HIV treatments decreased over the 8 years and were not related to risk behaviors. Conclusions: Beliefs about how HIV treatments impact HIV infectiousness remain associated with HIV transmission risk behavior and interventions targeting at-risk as well as HIV-positive men who have sex with men must directly address these beliefs and perceptions.
The Meaning of Torture

Despite being the subject of much recent scholarly work, torture remains an ambiguous concept. As recent legal arguments have made clear, such vagueness has important and immediate political consequences. This article makes a number of contributions towards resolving this ambiguity. First, it argues that the distinction between physical and psychological abuse is unwarranted. Second, it puts forward a logical basis for the distinction between torture and legally permissible punishments like incarceration. Third, it distinguishes between torture and related concepts like cruelty or sadism by stressing the instrumentality of torture. Ultimately, torture is defined as the systematic and deliberate infliction of severe pain or suffering on a person over whom the actor has physical control, in order to induce a behavioral response from that person.
Rainbow trout (Salmo gairdneri) semen: Effect of non-motile sperm on fertility

Abstract In salmonids, low fertility has been correlated with semen containing a low percentage of motile spermatozoa when diluted with an activating medium. This low motility, low fertility correlation does not appear to be due solely to an inadequate number of motile sperm per egg. Non-motile sperm may affect the interaction of motile sperm with the oocyte. To investigate the possible interference of non-motile spermatozoa on fertilization, oocytes of Salmo gairdneri were fertilized with varying proportions of non-motile (heat-inactivated) sperm before, after or simultaneously with control (non-heated) sperm. Fertility was assayed by monitoring the resultant embryonic development to the eyed stage. The motility of heat-inactivated sperm was zero and their mean fertility was negligible. Addition of heat-inactivated sperm in any proportion after control sperm did not affect fertility. Fertility of motile sperm was reduced when the heat-inactivated sperm were added first and their final concentration was equal to or greater than 90%, and when heat-inactivated sperm at a final concentration of 99% were added simultaneously with the motile sperm. Taken together, these data suggest that non-motile sperm can reduce the fertility of normal motile sperm, but this effect does not play a major role in the determination of the level of fertility in fish semen unless the concentration of motile sperm is less than 10%.
Three-dimensional Čerenkov tomography of energy deposition from ionizing radiation beams

Since its discovery during the 1930s the Cerenkov effect (light emission from charged particles traveling faster than the local speed of light in a dielectric medium) has been paramount in the development of high-energy physics research. The ability of the emitted light to describe a charged particle’s trajectory, energy, velocity, and mass has allowed scientists to study subatomic particles, detect neutrinos, and explore the properties of interstellar matter. However, to our knowledge, all applications of the process to date have focused on the identification of particles themselves, rather than their effect upon the surroundings through which they travel. Here we explore a novel application of the Cerenkov effect for the recovery of the spatial distribution of ionizing radiation energy deposition in a medium and apply it to the issue of dose determination in medical physics. By capturing multiple projection images of the Cerenkov light induced by a medical linear accelerator x-ray photon beam, we demonstrate the successful three-dimensional tomographic reconstruction of the imparted dose distribution.
Kant against Hobbes in Theory and Practice

In the middle section of Theory and Practice, Kant speaks briefly `against Hobbes'; but for a fuller version of Kant's anti-Hobbesianism one must turn to the three Critiques, the Groundwork, and Religion within the Limits of Reason Alone. It is in those works that one learns that, for Kant, Hobbes's notion of `will' as fully determined `last appetite' destroys the freedom needed to take `ought' or moral necessity as the motives for self-determined action; that Hobbes' s version of the social contract is thus incoherent; that Hobbes is not even able to show how moral ideas (i.e. `ought') are conceivable through the `pressure' of `outward objects'. For Kant, in short, Hobbes has no adequate notions of will, freedom, moral necessity, ideation, or even obligatory contract, and therefore fails in his own stated aims.
Platelet activating factor‐acetylhydrolase in insects: Identification and partial characterization of a 1‐alkyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine acetylhydrolase in a cell‐free system of Heliothis

A specific acetylhydrolase that inactivates platelet activating factor (PAF; 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine), a potent cellular mediator in mammalian cells, by removal of the sn-2 acetyl moiety, has been found in the cytosolic fraction of several postembryonic developmental stages and specific tissues of the corn earworm, Heliothis zea (Boddie). Effects of magnesium, calcium, EGTA, deoxycholate, dithiothreitol, diisopropylfluorophosphate, egg phosphatidylcholine, and an acylacetyl-glycerophosphocholine show that hydrolysis of the acetate moiety is due to a specific acetylhydrolase for PAF. The activity does not appear to be due to a typical cellular phospholipase A2 that utilizes phospholipid substrates with a long-chain acyl group at position sn-2 of glycerol. Specific activities and properties of the acetylhydrolase from this insect match closely with those described from tissues of vertebrate animals.
Motion Analysis in the Hemicochlea

Optical flow techniques are often used to estimate velocity fields to represent motion in successive video images. Usually the method is mathematically ill-posed, because the single scalar equation representing the conservation of local intensity contains more than one unknown velocity component. Instead of regularizing the problem using optimization techniques, we formulate a well-posed problem for the gerbil hemicochlea preparation by introducing an in-plane incompressibility constraint, and then show that local brightness is also conserved. We solve the resulting system using a Lagrangian description of the conservation equations. With this approach, the displacement of isointensity contours on sequential images determines the normal component of velocity of an area element, while the tangential component is computed from the local constant area constraint. We have validated our method using pairs of images generated from our calculations of the vibrational deformation in a cross section of the organ of Corti and tectorial membrane in the mammalian cochlea, and quantified the superior performance of our method when complex artificial motion is applied to a noisy image obtained from the hemicochlea preparation. The micromechanics of the organ of Corti and the tectorial membrane is then analyzed by our new method.
Phase image characterization of ventricular contraction in left and right bundle branch block

The phase image is a computer-derived functional image, based on the analysis of the time versus radioactivity curve in each pixel location of the multiple gated blood pool scintigram. Within the ventricular regions of interest, the phase angle is roughly equivalent to the time of onset of counts reduction or to the time of onset of ventricular contraction and is expressed in degrees from 0 to 360 degrees. A gray scale-coded image of such a regional phase angle, the phase image, can be looked on as a map of sequential contraction. This method was applied in 33 patients without severe contraction abnormality including 16 patients with normal conduction, 9 with right bundle branch block and 8 with left bundle branch block. In patients with normal conduction the pattern of phase angle distribution, representing the pattern of ventricular contraction, was homogeneous and symmetric in both the left and right ventricles. Analysis in this normal group indicated a slight but significant difference between the mean (+/- standard deviation) phase angle of the left ventricle (8.5 +/- 11.8 degrees) and that of the right ventricle (13.6 +/0 12.9 degrees, p = 0.01). There was a slight, but nonsignificant difference between mean intrapatient left and right ventricular phase angle onset (1.9 +/- 6.5 degrees). The mean phase angle of the right ventricle in patients with right bundle branch block (27.6 +/- 14.2 degrees) and of the left ventricle in those with left bundle branch block (21.9 +/- 14.0 degrees) was delayed compared with that in patients with normal conduction (p less than 0.05 for both). The mean intrapatient difference between left and right ventricular mean phase angles in patients with normal conduction (-5.2 +/- 6.8 degrees) was significantly different from that in patients with right (-21.8 +/- 10.3 degrees, p less than 0.001) or left (21.8 +/- 6.8 degrees, p less than 0.001) bundle branch block. The mean intrapatient difference between onset of left and right ventricular phase angles was also significantly different from normal in patients with right (-10.6 +/- 7.5 degrees, p less than 0.005) or left (18.7 +/- 8.3 degrees, p = 0.01) bundle branch block. Although phase imaging is not without artifactual error, this study demonstrates that the phase image can characterize familiar conduction abnormalities. It presents the potential for application as a general noninvasive tool in the investigation of the timing and sequence of ventricular contraction in patients with normal or abnormal ventricular activation.
Nω-nitro-L-arginine attenuates the accumulation of aortic cyclic GMP and the hypotension produced by zaprinast

To determine if N omega-nitro-L-arginine (NNA), an inhibitor of the synthesis and/or release of endothelium-derived relaxing factor (EDRF), alters the response to zaprinast, a selective inhibitor of cyclic GMP (cGMP) phosphodiesterase, zaprinast (3-30 mg/kg) or vehicle (1 ml/kg) was given to conscious, spontaneously hypertensive rats (SHR) in a cumulative i.v. dose-response manner 30 min after pretreatment with NNA (1 or 3 mg/kg) or saline (1 ml/kg). Mean arterial pressure (MAP) was measured 5 min after each dose of zaprinast. Five minutes after the last dose of zaprinast (30 mg/kg), the rats were anesthetized with pentobarbital (25 mg i.v.). A segment of the abdominal aorta was freeze-clamped in situ and removed for the determination of cGMP levels. NNA (3 mg/kg) decreased basal aortic cGMP levels by 54% and increased MAP by 37 +/- 2 mm Hg. Zaprinast (30 mg/kg) increased aortic cGMP by 187% and decreased MAP by 49 +/- 4 mm Hg. NNA (3 mg/kg) reduced the accumulation of cGMP in aortic tissue (from 4.1 +/- 0.4 to 1.3 +/- 0.1 fmol/microgram protein) and attenuated the depressor response (from -49 +/- 4 to -31 +/- 4 mm Hg) produced by zaprinast. These data are consistent with the hypothesis that NNA inhibits the tonic release of EDRF and that the depressor effects of zaprinast are due, at least in part, to the potentiation of the vasodilator effects of EDRF in vivo. Moreover, since the changes in MAP produced by NNA and zaprinast were significantly correlated with cGMP levels in aortic tissue, the concentration of cGMP in vascular tissue may be a determinant of blood pressure in SHR.
Radioimmunoassay for the quantitative determination of hesperidin and analysis of its distribution in Citrus sinensis

Abstract A simple and sensitive radioimmunoassay (RIA) for the citrus flavanone hesperidin and other flavonoid 7-rutinosides is described. The assay utilizes antibodies raised against a hesperidin 4- O -carboxymethyl-oxime hapten and a tritiated radiotracer prepared by direct reduction of hesperidin with NaB[3-H]4. The detection limit of the assay is 0.2 ng/0.1 ml (0.3 pmol/0.1 ml and the measuring range extends to 10 ng/0.1 ml (16.4 pmol/0.1 ml). This assay is specific for flavonoid rutinosides, is characterized by a low coefficient of variation, and shows good correlation with HPLC for the quantification of hesperidin in oranges. The application of this method in determining the distribution of hesperidin in leaves, fruit, seeds, and seedlings of Citrus sinensis is also reported.
GA Based Engineering Design Optimization Using Fuzzy Constraints and Fitness Functions

This paper is focused on constrained nonlinear optimization problems that are encountered in engineering design. These problems often involve imprecise objectives as well as constraints and as such do not lend themselves well to the application of conventional nonlinear optimization techniques. In this paper, fuzzy logic, in conjunction with genetic algorithms, is used to address this issue. In particular, fuzzy sets are used to define the constraints/objective functions while a genetic search algorithm is used to find an approximation of the so-called pareto-optimal solution. It is shown, via the application of this approach to two classic problems in the field, that the proposed methodology is effective in terms of finding a solution that is within acceptable proximity of the pareto-optimal front. Moreover, a comparative analysis of the performance of the proposed approach with those reported in the literature reveals the computational efficiency of this methodology.
L2 error estimation for DGFEM for elliptic problems with low regularity

Abstract This paper presents an error estimate in the L 2 -norm for the discontinuous Galerkin finite element methods (DGFEM) for elliptic problems with low regularity solutions. The Raviart–Thomas interpolation operator is employed to derive the new result, which complements the mesh-dependent energy norm error estimates in Gudi (2010) [2] . Numerical results corroborate the theoretical analysis.
Evaluation of muscle force prediction models of the lumbar trunk using surface electromyography

Optimization-based models for prediction of muscle forces in the lumbar region of the torso are used to estimate the forces acting on spinal motion segments, especially for asymmetric tasks. The objectives of this study were to determine (a) which of four torso model formulations best predicted the electromyographic data, (b) the difference in muscular contribution to spinal compression force for the four models, and (c) the effect of using the lowest possible muscle stress bound in the model formulation. An approach for the investigation of competing optimization model formulations was developed and was illustrated with electromyographic data from static asymmetric loading conditions. This method is based on (a) the choice of experimental conditions in which models predict decidedly different muscle forces, and (b) the ability to ensure that the experimental conditions are such that the minimum number of assumptions about the force-electromyogram relationship must be made in order to choose between competing model predictions. Of the four models analyzed, only the formulation with an objective function that was the sum of cubed muscle stresses predicted the electromyographic data acceptably. The muscular contribution to spinal compression force predicted by these models differed by as much as 160% for some experimental conditions. The use of the lowest possible muscle stress bound does not appear to predict muscle forces that are in agreement with electromyographic data.
Molecular aspects of genetic recombination and their relevance to cutaneous biology.

Genetic recombination is reviewed with regard to: DNA structure; breaking and rejoining versus copy choice; hybrid overlap and synapsis; enzymes for breaking and joining; the recombination enzymes of phage lambda; and cutaneous events requiring breaking and rejoining of DNA. The lack of endonucleolytic activity required for excision of UV-induced pyrimidine dimers in DNA of patients with xeroderma pigmentosum is discussed in relation to the repair of UV-induced injuries to DNA. (HLW)
"Analyzing gossip in workplace email" by Tanushree Mitra and Eric Gilbert, with Ching-man Au Yeung as coordinator

We spend a significant part of our lives chatting about other people. In other words, we all gossip. Although sometimes a contentious topic, various researchers have shown gossip to be fundamental to social life---from small groups to large, formal organizations. Adopting the Enron email dataset and natural language techniques, we present the first study of gossip in a large CMC corpus. We find that workplace gossip is common at all levels of the organizational hierarchy, with people most likely to gossip with their peers and that it is more likely for an email to contain gossip if targeted to a smaller audience. Also, gossip appears as often in personal exchanges as it does in formal business communication. Exploring the sentiment of gossip, we observe that gossip is in fact quite often negative. Our study provides empirical evidence of an under-researched yet important societal phenomenon and provides empirical insights by testing existing gossip theories originating from anthropology, on a real world large email dataset.
Photoluminescence And Electron Paramagnetic Resonance Of Nitrogen-Doped Zinc Selenide Epilayers

Photoluminescence (PL) and electron paramagnetic resonance (EPR) studies were performed on a series of ZnSe samples grown by molecular beam epitaxy. The PL has been studied as a function of excitation wavelength, power, temperature, and time. The PL data indicates that the broad emission from a heavily nitrogen-doped ZnSe film is composed of three distinct recombination processes. The EPR spectra taken at 8 K and 9.45 GHz show an isotropic signal at g = 2.0027(3) which we attribute to singly ionized selenium vacancies (Vse+). The PL and EPR data help to clarify the role of defects in the compensation of heavily nitrogen-doped ZnSe thin films.
Influences of secondary disturbances on lodgepole pine stand development in Rocky Mountain National Park.

Although high-severity fire is the primary type of disturbance shaping the structure of lodgepole pine (Pinus contorta) stands in the southern Rocky Mountains, many post-fire stands are also affected by blowdown, low-severity surface fires, and/or outbreaks of mountain pine beetle (MPB; Dendroctonus ponderosae). The ecological effects of these secondary disturbances are poorly understood but are potentially important in the context of managing for ecological restoration and fire hazard mitigation. We investigated the effects of blowdown, surface fires, and MPB outbreaks on demographic processes in post-fire lodgepole pine stands in Rocky Mountain National Park, Colorado, USA. We used dendroecological methods to reconstruct stand characteristics prior to and following secondary disturbances for paired stands with and without secondary disturbances. Surface fire events do not kill canopy trees or trigger pulses of recruitment and as such do not have detectable influences on stand development. In contrast, b...