cssi/SciSciGPT-SciSciNet huggingface dataset:
Analytical Shock Response of a Transversely Point-Loaded Linear Rectangular Plate

Ballistic shock, the strong vibrations that propagate through a vehicle structure after a ballistic impact, can damage electronic components that are mounted on various interior locations of the vehicle. To protect onboard critical electronic components from ballistic shock damage, predicted shock response spectra (SRS) are used as design guidelines in the selection of shock isolation devices. Current technology to predict shock response intensity at component mounting locations includes Finite Element Analysis, Statistical Energy Analysis, and various other modeling approaches. The Army Research Laboratory is implementing a process to determine component damage probability based on a numerical modal superposition method. This process allows detailed modeling of an entire vehicle (including instrumentation racks) but requires months of effort to perform skillful FEA modeling. Such an expenditure is acceptable only for unique high value vehicles, and is impractical for analysis of many vehicles. Therefore it is desirable to investigate alternative shock analysis methods that are simple and general (i.e., independent of specific vehicle configurations). Although such methods could entail reduced accuracy, for situations that are applicable they would eliminate the need of time-consuming finite element modeling, and could used in a variety of vehicles. As such, the methods could be used for “screening” for rapid identification of potential shock-damage issues. If necessary, further detailed analysis could be accomplished subsequently. When an armored vehicle is subjected to a non-perforating large-caliber munitions impact or blast, direct mounted components that are near the impact location will always risk the highest damage potential. Live fire ballistic tests and laboratory experiments as well as numerical modeling have proved this observation. The research presented in this paper develops, from an exact continuous model, a constant- and lumped-parameter, linear matrix model of a homogeneous, rectangular, simply-supported plate subject to transverse ballistic shock. The model is provided in a form suitable for eigen-analysis intended to yield kinematic responses for SRS determination. Damping can be included in either Rayleigh or modal form. The enabled “same-plate” shock analysis, while not encompassing an entire military vehicle, would treat the most severe cases of shock response, for components mounted directly on the impacted plate.Copyright © 2006 by ASME
Drought Policy in the U.S. and Australia: A Comparative Analysis

: Federal and state governments in the United States and Australia have come to play a key role in attempts to mitigate the impact of drought. Government actions have usually taken the form of loans and grants to individual citizens, businesses and municipalities experiencing the hardship of drought. Most of these actions have occurred in an environment of crisis management, rather than as a result of clearly stated policy objectives. Based on a review and evaluation of recent drought policy in the United States and Australia, recommendations are offered on ways to improve the United States’approach. A national drought plan is suggested as an efficient mechanism through which these recommendations could be implemented. States should also become more actively involved in drought assessment and response, but these actions must be coordinated with federal actions.
Activation of the complement cascade by Bordetella pertussis

Bordetella pertussis must survive the defenses of the human respiratory tract including the complement system. The BrkA (Bordetella resistance to killing) protein prevents killing by the antibody-dependent classical pathway. In this study, the ability of B. pertussis to activate the human complement cascade by other pathways was examined. B. pertussis was not killed in serum depleted of C2, however serum depleted for factor B killed B. pertussis as efficiently as intact serum, suggesting complement activation occurred exclusively by the classical pathway. B. pertussis was not killed by serum depleted of antibody, suggesting the bacteria fail to activate the antibody-independent branches of the classical pathway, including the mannose binding lectin pathway. Mutants lacking the terminal trisaccharide of lipopolysaccharide retained the complement-resistant phenotype, suggesting this structure does not influence activation of complement.
Phase separation and critical phenomena in biomimetic ternary lipid mixtures

Lipid phase behaviour in biomimetic ternary mixtures has become a rich area of research and this review will provide a background to the many studies recently carried out, describing important advancements and future prospects for the field. In the liquid crystal community lipids are traditionally interesting as lyotropic materials and in this sense a large amount of work has been carried out on different systems. This paper will not focus on lyotropic phases but instead will concentrate on the thermotropic phase behaviour of ternary lipid mixtures. We will discuss thermotropic phase diagrams and critical phenomena in these systems, including their relationships to biological membranes. Interest in the links between lipid thermodynamics and cell function has grown steadily over the past three decades and most of the recent work in these areas has been motivated by a desire to link the phase behaviour of simple lipid mixtures to lateral organisation in the cell membrane. The literature in this field is ext...
Brain kallikrein-kinin system abnormalities in spontaneously hypertensive rats.

Abstract The objective of the present study was to determine whether the brain kallikrein-kinin system differs between spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) and if so, whether any detected differences occur before the development of hypertension in SHR. We measured cerebrospinal fluid levels of various components of the system in adult and young prehypertensive SHR and WKY. Cerebrospinal fluid kinin concentration and appearance rate were higher in SHR. Cerebrospinal fluid active kallikrein level and kininogenase activity were also higher in adult SHR. In addition, cerebrospinal fluid kinin concentration and appearance rate were higher in prehypertensive, 5- to 6-week-old SHR compared with age-matched WKY. However, no differences in cerebrospinal fluid kallikrein or kininogenase activity were observed between the two strains of young rats. Cerebrospinal fluid kinin concentration was higher in young versus adult rats of the same strain. In WKY, cerebrospinal fluid kallikrein also decreased with age although cerebrospinal fluid kallikrein concentration did not decrease in young and adult SHR. Together, these data suggest that there is a hyperactive kallikrein-kinin system in the brain of SHR that may contribute to the hypertensive state in this animal model.
La colección John Alden Mason: una documentación sonora para la historia de Puerto Rico

Resumen es: Esta nota de investigacion da cuenta de la coleccion de musica popular recopilada por el antropologo John Alden Mason en Puerto Rico entre 1914 y 1915. L...
The Ubr2 Gene is Expressed in Skeletal Muscle Atrophying as a Result of Hind Limb Suspension, but not Merg1a Expression Alone.

Skeletal muscle (SKM) atrophy is a potentially debilitating condition induced by muscle disuse, denervation, many disease states, and aging. The ubiquitin proteasome pathway (UPP) contributes greatly to the protein loss suffered in muscle atrophy. The MERG1a K+ channel is known to induce UPP activity and atrophy in SKM. It has been further demonstrated that the mouse ether-a-gogo-related gene (Merg)1a channel modulates expression of MURF1, an E3 ligase component of the UPP, while it does not affect expression of the UPP E3 ligase Mafbx/ATROGIN1. Because the UBR2 E3 ligase is known to participate in SKM atrophy, we have investigated the effect of Merg1a expression and hind limb suspension on Ubr2 expression. Here, we report that hind limb suspension results in a significant 25.6% decrease in mouse gastrocnemius muscle fiber cross sectional area (CSA) and that electro-transfer of Merg1a alone into gastrocnemius muscles yields a 15.3% decrease in CSA after 7 days. More interestingly, we discovered that hind limb suspension caused a significant 8-fold increase in Merg1a expression and a significant 4.7-fold increase in Ubr2 transcript after 4 days, while electro-transfer of Merg1a into gastrocnemius muscles resulted in a significant 6.2-fold increase in Merg1a transcript after 4 days but had no effect on Ubr2 expression. In summary, the MERG1a K+ channel, known to induce atrophy and MURF1 E3 ligase expression, does not affect UBR2 E3 ligase transcript levels. Therefore, to date, the MERG1a channel’s contribution to UPP activity appears mainly to be through up-regulation of Murf1 gene expression.
Declarative object identity using relation types

Object-oriented languages define the identity of an object to be an address-based object identifier. The programmer may customize the notion of object identity by overriding the equals() and hashCode() methods following a specified contract. This customization often introduces latent errors, since the contract is unenforced and at times impossible to satisfy, and its implementation requires tedious and error-prone boilerplate code. Relation types are a programming model in which object identity is defined declaratively, obviating the need for equals() and hashCode() methods. This entails a stricter contract: identity never changes during an execution. We formalize the model as an adaptation of Featherweight Java, and implement it by extending Java with relation types. Experiments on a set of Java programs show that the majority of classes that override equals() can be refactored into relation types, and that most of the remainder are buggy or fragile.
Virgil, aeneid 5.835-6

This has all the appearance of being a straightforward, even conventional, transition. Indeed, the conceit of Night′s chariot is common and has a history stretching back at least as far as the beginning of the fifth century B.C. Night is elsewhere described by Virgil as umida , the epithet reflecting the traditional view that Night, like Dawn (cf. Theocr. 2.148), arises from and sinks back into the stream of Ocean. In fact, the chariot of Night had been referred to as recently as lines 721 and 738 of this book, in the latter instance with the epithet umida applied to Night. What is new and interesting in our passage is the ‘meta caeli’ round which Night′s chariot turns. The effect of this novelty is to make of Night′s vehicle a racing chariot, as it is the chariots in the Circus that must negotiate a meta. The programmatic reasons for Virgil′s having done this in Book 5 are obvious. Earlier in the book Virgil had described the games held in honour of the anniversary of Anchises′ death. The first and most elaborately portrayed event in these games had been the boat-race, which is plainly modelled on the chariot-race in Iliad 23, the first and most elaborately portrayed event in the funeral games for Patroclus. Just as Achilles had required the competing chariots to race once around a distant turning-post, so Aeneas requires the competing ships to race once around a rock out at sea, which rock is three times called a meta (5.129, 159, 171). A simile comparing the sailors and their ships to charioteers and their teams (5.144–7) makes the connection explicit.
Physiological characterization of Streptococcus bovis mutants that can resist 2-deoxyglucose-induced lysis

Streptococcus bovis JB1 does not normally lyse, but stationary phase lysis can be induced by including 2-deoxyglucose (2DG) in the growth medium. Isolates deficient in glucose/2DG phosphotransferase activity (PTS−) also lysed when 2DG was present (Lys+) and this result indicated that 2DG phosphorylation via the PTS was not an obligate requirement for 2DG-induced lysis. Cells and cell walls from 2DG-grown cultures lysed faster when proteinase K was added, but glucose-grown cultures and cell walls were not affected. A lipoteichoic acid (LTA) extract (aqueous phase from hot phenol treatment) from glucose-grown cells inhibited the lysis of 2DG-grown cultures, but a similar extract prepared from 2DG-grown cells was without effect. Thin-layer chromatography and differential staining indicated that wild-type and Lys+ PTS− cells incorporated 2DG into LTA, but lysis-resistant cultures (Lys− PTS+ and Lys− PTS−) did not. LTA from lysis-resistant (Lys− PTS+ and Lys− PTS−) cells grown with glucose and 2DG also prevented 2DG-dependent lysis of the wild-type. LTA could not inhibit degradation of cell walls isolated from 2DG-grown cultures, but LTA inhibited the lysis of Micrococcus lysodeikticus (Micrococcus luteus) cells that were exposed to supernatants from 2DG-grown S. bovis cultures. Group D streptococci (including S. bovis) normally have an α-1,2 linked glucose disaccharide (kojibiose) in their LTA, but kojibiose cannot be synthesized from 2DG. This observation suggested that the kojibiose moiety of LTA was involved in autolysin inactivation. Wild-type S. bovis had ATP- as well as PEP-dependent mechanisms of 2DG phosphorylation and one lysis-resistant phenotype (Lys− PTS−) had reduced levels of both activities. However, the Lys− PTS+ phenotype was still able to phosphorylate 2DG via ATP and PEP and this result indicated that some other step of 2DG incorporation into LTA was being inhibited. Based on these results, growth in the presence of 2DG appears to prevent synthesis of normal LTA, which is involved in the regulation of autolytic enzymes.
Mercury dynamics in a coastal aquifer: Maunalua Bay, Oʻahu, Hawaiʻi

We evaluated the influence of groundwater–seawater interaction on mercury dynamics in Maunalua Bay, a coral reef ecosystem located on the south shore of Oʻahu, Hawaiʻi, by combining geochemical data with submarine groundwater discharge (SGD) rates. During a rising tide, unfiltered total mercury (U-HgT) concentrations in seawater increased from ∼6 to 20 pM at Black Point (west Bay) and from ∼2.5 to 8 pM at Niu (central Bay). We attribute this change to an increase in suspended particulate matter at high tide. Approximately 90% of mercury in groundwater at Niu was in the filtered (<0.45 μm) fraction, with a concentration of ∼4 pM. Groundwater discharge during a period of amplified SGD at Niu appeared to contribute to an increase in total mercury concentrations in filtered seawater (F-HgT; 1.2 to 2.4 pM) and in unfiltered seawater (U-HgT; 2.5 to 3.2 pM). The larger magnitude of change in F-HgT relative to U-HgT suggests mercury complexation and/or solubility dynamics in seawater were altered by the addition of groundwater. We used site specific 222Rn derived SGD flux estimates and groundwater F-HgT concentrations to calculate mercury loadings at Black Point (∼3 nmol m−2 d−1) and at Niu (∼1 nmol m−2 d−1). We calculated a weighted average Maunalua Bay groundwater mercury flux of 0.68 ± 0.67 mol yr−1 by combining the proportional flux of F-HgT from three distinct SGD zones, and place these results into a broader context by comparing and contrasting flux estimates from locations around the world. Results from existing SGD studies should be evaluated to develop future sampling strategies that address more targeted questions about mercury biogeochemical cycling at the groundwater–seawater interface.
Current Perspectives on the Beneficial Role of Ginkgo biloba in Neurological and Cerebrovascular Disorders

Ginkgo biloba extract is an alternative medicine available as a standardized formulation, EGb 761®, which consists of ginkgolides, bilobalide, and flavonoids. The individual constituents have varying therapeutic mechanisms that contribute to the pharmacological activity of the extract as a whole. Recent studies show anxiolytic properties of ginkgolide A, migraine with aura treatment by ginkgolide B, a reduction in ischemia-induced glutamate excitotoxicity by bilobalide, and an alternative antihypertensive property of quercetin, among others. These findings have been observed in EGb 761 as well and have led to clinical investigation into its use as a therapeutic for conditions such as cognition, dementia, cardiovascular, and cerebrovascular diseases. This review explores the therapeutic mechanisms of the individual EGb 761 constituents to explain the pharmacology as a whole and its clinical application to cardiovascular and neurological disorders, in particular ischemic stroke.
Characterization of RNA Determinants Recognized by the Arginine- and Proline-Rich Region of Us11, a Herpes Simplex Virus Type 1-Encoded Double-Stranded RNA Binding Protein That Prevents PKR Activation

The herpes simplex virus Us11 gene product inhibits activation of the cellular PKR kinase and associates with a limited number of unrelated viral and cellular RNA molecules via a carboxyl-terminal 68-amino-acid segment rich in arginine and proline. To characterize the determinants underlying the recognition of an RNA target by Us11, we employed an in vitro selection technique to isolate RNA ligands that bind Us11 with high affinity from a population of molecules containing an internal randomized segment. Binding of Us11 to these RNA ligands is specific and appears to occur preferentially on conformational isoforms that possess a higher-order structure. While the addition of unlabeled poly(I · C) reduced binding of Us11 to a selected radiolabeled RNA, single-stranded homopolymers were not effective competitors. Us11 directly associates with poly(I · C), and inclusion of an unlabeled selected RNA in the reaction reduces poly(I · C) binding, while single-stranded RNA homopolymers have no effect. Finally, Us11 binds to defined, double-stranded RNA (dsRNA) molecules that exhibit greater sequence complexity. Binding to these dsRNA perfect duplexes displays a striking dependence on length, as 39-bp or shorter duplexes do not bind efficiently. Furthermore, this interaction is specific for dsRNA as opposed to dsDNA, implying that the Us11 RNA binding domain can distinguish nucleic acid duplexes containing 2′ hydroxyl groups from those that do not. These results establish that Us11 is a dsRNA binding protein. The arginine- and proline-rich Us11 RNA binding domain is unrelated to known dsRNA binding elements and thus constitutes a unique recognition motif that interacts with dsRNA. The ability of Us11 to bind dsRNA may be important for inhibiting activation of the cellular PKR kinase in response to dsRNA.
RF modes in the PEP-II shielded vertex bellows

Experimental and simulation study of RF modes were carried out for the complicated geometry of the shielded vertex bellows near the IP region of the PEP-II B-factory. A beam position monitor button electrode located 50 cm from the bellows provides a signal for spectrum measurement. Calculations indicate monopole, dipole and quadrupole modes can exist in the bellows structure near the experimentally observed frequency region of 5 GHz. The observed modes are correlated to the bellows heating. The beam-generated fields are scattered by the masks, taper and axial offsets and heat the bellows by coupling through the RF shield fingers.
Multiple-Use Atomizers in Outpatient Otolaryngology Clinics are not Necessarily an Infectious Risk:

Abstract Objective We sought to determine the risk of bacterial transmission from multiple-use atomizers in an outpatient otolaryngology clinic. Study design and setting Atomizers in 6 examination rooms were analyzed for bacterial contamination. Sterility of associated tubing from 1 atomizer was assessed. Multidose drug solutions in the atomizers (phenylephrine and tetracaine) were cultured multiple times over a 2-week period. Serial dilutions of the original sample were cultured to minimize inhibitory effects of antiseptic agents in the drug formulations. Results No bacteria were recovered from tubing cultures. Only 2 (0.6%) of 336 cultures of the drug solutions yielded bacterial growth. In both cases, coagulase-negative Staphylococcus was recovered in 1 of the dilutions prepared from original samplings. Conclusion Multiple-use atomizers that contain phenylephrine and tetracaine solutions with bacteriostatic preservatives in an outpatient otolaryngology clinic do not yield significant bacterial growth and, when used as described, do not pose an infectious risk of bacterial transmission between patients.
Auras in generalized epilepsy

Objective: We studied the frequency of auras in generalized epilepsy (GE) using a detailed semistructured diagnostic interview. Methods: In this cross-sectional study, participants with GE were drawn from the Epilepsy Phenome/Genome Project (EPGP). Responses to the standardized diagnostic interview regarding tonic-clonic (grand mal) seizures were then examined. This questionnaire initially required participants to provide their own description of any subjective phenomena before their “grand mal seizures.” Participants who provided answers to these questions were considered to have an aura. All participants were then systematically queried regarding a list of specific symptoms occurring before grand mal seizures, using structured (closed-ended) questions. Results: Seven hundred ninety-eight participants with GE were identified, of whom 530 reported grand mal seizures. Of these, 112 (21.3%) reported auras in response to the open-ended question. Analysis of responses to the closed-ended questions suggested that 341 participants (64.3%) experienced at least one form of aura. Conclusions: Auras typically associated with focal epilepsy were reported by a substantial proportion of EPGP subjects with GE. This finding may support existing theories of cortical and subcortical generators of GE with variable spread patterns. Differences between responses to the open-ended question and closed-ended questions may also reflect clinically relevant variation in patient responses to history-taking and surveys. Open-ended questions may underestimate the prevalence of specific types of auras and may be in part responsible for the underrecognition of auras in GE. In addition, structured questions may influence participants, possibly leading to a greater representation of symptoms.
Resolution of facial stimulation in otosclerotic cochlear implants.

Abstract Objectives We examined the incidence of facial nerve stimulation in a population of patients with otosclerosis implanted with the Nucleus 22, Clarion 1.2, or Clarion High Focus (CHF) device. Study design and setting A retrospective chart review was used for 147 patients who had been implanted with electronic cochlear devices at the University of Minnesota between June 1986 and February 2001. Seventy-four patients were implanted with the Nucleus 22, 41 patients were implanted with the Clarion 1.2 (without a positioner), and 32 patients were implanted with the CHF I or II. Results Eleven (14.9%) of the 74 patients implanted with the Nucleus 22 device had facial stimulation. There were 9 patients with otosclerosis. Seven (78%) of the 9 patients with otosclerosis had facial stimulation. One (2.4%) of the 41 patients implanted with the Clarion 1.2 device (without a positioner) had facial stimulation and that 1 (100%) patient in the group had otosclerosis. There were 4 patients in the CHF group with otosclerosis. One patient experienced stimulation, but it was possible to decrease maximum current levels and still use the electrode pair. Conclusion Facial stimulation appears to be less problematic in patients with otosclerosis implanted with the CHF devices.
Cost-Effectiveness Analysis of Total Ankle Arthroplasty

Background: There is renewed interest in total ankle arthroplasty as an alternative to ankle fusion in the treatment of end-stage ankle arthritis. Despite a lack of long-term data on the clinical outcomes associated with these implants, the use of ankle arthroplasty is expanding. The purpose of this cost-effectiveness analysis was to evaluate whether the currently available literature justifies the emerging use of total ankle arthroplasty. This study also identifies thresholds for the durability and function of ankle prostheses that, if met, would support more widespread dissemination of this new technology. Methods: A decision model was created for the treatment of ankle arthritis. The literature was reviewed to identify possible outcomes and their probabilities following ankle fusion and ankle arthroplasty. Each outcome was weighted for quality of life with use of a utility factor, and effectiveness was expressed in units of quality-adjusted life years. Gross costs were estimated from Medicare charge and reimbursement data for the relevant codes. The effect of the uncertainty of estimates of costs and effectiveness was assessed with sensitivity analysis. Results: The reference case of our model assumed a ten-year duration of survival of the prosthesis, resulting in an incremental cost-effectiveness ratio for ankle arthroplasty of $18,419 per quality-adjusted life year gained. This reflects a gain of 0.52 quality-adjusted life years at a cost of $9578 when ankle arthroplasty is chosen over fusion. This ratio compares favorably with the cost-effectiveness of other medical and surgical interventions. Sensitivity analysis determined that the cost per quality-adjusted life year gained with ankle arthroplasty rises above $50,000 if the prosthesis is assumed to fail before seven years. Treatment options with ratios above $50,000 per quality-adjusted life year are commonly considered to have limited cost-effectiveness. This threshold is also crossed when the theoretical functional advantages of ankle arthroplasty are eliminated in sensitivity analysis. Conclusions: The currently available literature has not yet shown that total ankle arthroplasty predictably results in levels of durability and function that make it cost-effective at this time. However, the reference case of this analysis does demonstrate that total ankle arthroplasty has the potential to be a cost-effective alternative to ankle fusion. This reference case assumes that the theoretical functional advantages of ankle arthroplasty over ankle fusion will be borne out in future clinical studies. Performance of total ankle replacement will be better justified if these thresholds are met in published long-term clinical trials. Level of Evidence: Economic and decision analysis, Level II-1 (clinically sensible costs and alternatives; values obtained from limited studies; multiway sensitivity analyses). See Instructions to Authors for a complete description of levels of evidence.
THE EFFECT OF FLORAL HERBIVORY ON MALE AND FEMALE REPRODUCTIVE SUCCESS IN ISOMERIS ARBOREA

Flower-feeding herbivores can directly reduce plant reproduction by consuming gametes. They may have additional indirect effects if their damage disrupts pollinator service and causes uneaten gametes to go unused. In a two-year study we investigated direct and indirect effects of florivory by a pollen beetle, Meligethes rufimanus, on the male and female reproductive success of the andromonoecious shrub, Isomeris arborea. We measured pollen export, pollen receipt, fruit set, and outcrossing rates on plants exposed to herbivores (most flowers damaged) and protected from herbivores (few flowers damaged) by systemic insecticide. Pollen export per undamaged flower was reduced by one-half in exposed plants, as estimated by pollinator transfer of florescent dye, which demonstrated indirect negative effects on male reproductive success. Damaged flowers on exposed plants had a lower stigmatic pollen load than undamaged flowers on either exposed or protected plants. Furthermore, exposed plants produced fewer fruits and seeds during the year than protected plants. Although damage reduces pollen receipt, hand pollination experiments showed that neither exposed nor protected plants were pollen limited, which suggests that floral herbivores primarily affect female function through their direct destruction of gametes. Outcrossing rates did not differ between exposed plants (ts = 0.920) and protected plants (ts = 0.806), suggesting that herbivory does not indirectly reduce plant reproductive success by inducing autogamy and subsequent inbreeding depression. Overall, floral herbivory has direct consequences for both male and female reproductive success, but indirect effects are limited to male function.
Achievement Orientation and Psychological Involvement in Job Tasks: The Interactive Effects of Work Alienation and Intrinsic Job Satisfaction1

As the tendency to strive for competence in one's work, achievement orientation is considered to engender psychological involvement in job tasks (i.e., job involvement-role). However, this study posits that the positive relationship between achievement orientation and job involvement-role is moderated by an attitude of disaffection toward the work role in general (i.e., high work alienation) and by dissatisfaction with the content of one's present job (i.e., low intrinsic job satisfaction). The results of hierarchical moderated regression analyses support the existence of complex interactions and suggest that a positive outlook toward the work role is necessary for achievement orientation to translate into greater job involvement-role. Practical implications and directions for future research on job involvement role are considered.
The second messenger cyclic Di-GMP regulates Clostridium difficile toxin production by controlling expression of sigD

The Gram-positive obligate anaerobe Clostridium difficile causes potentially fatal intestinal diseases. How this organism regulates virulence gene expression is poorly understood. In many bacterial species, the second messenger cyclic di-GMP (c-di-GMP) negatively regulates flagellar motility and, in some cases, virulence. c-di-GMP was previously shown to repress motility of C. difficile. Recent evidence indicates that flagellar gene expression is tightly linked with expression of the genes encoding the two C. difficile toxins TcdA and TcdB, which are key virulence factors for this pathogen. Here, the effect of c-di-GMP on expression of the toxin genes tcdA and tcdB was determined, and the mechanism connecting flagellar and toxin gene expressions was examined. In C. difficile, increasing c-di-GMP levels reduced the expression levels of tcdA and tcdB, as well as that of tcdR, which encodes an alternative sigma factor that activates tcdA and tcdB expression. We hypothesized that the C. difficile orthologue of the flagellar alternative sigma factor SigD (FliA; σ(28)) mediates regulation of toxin gene expression in response to c-di-GMP. Indeed, ectopic expression of sigD in C. difficile resulted in increased expression levels of tcdR, tcdA, and tcdB. Furthermore, sigD expression enhanced toxin production and increased the cytopathic effect of C. difficile on cultured fibroblasts. Finally, evidence is provided that SigD directly activates tcdR expression and that SigD cannot activate tcdA or tcdB expression independent of TcdR. Taken together, these data suggest that SigD positively regulates toxin genes in C. difficile and that c-di-GMP can inhibit both motility and toxin production via SigD, making this signaling molecule a key virulence gene regulator in C. difficile.
An Unsteady Velocity Formulation for the Edge of the Near-Wall Region

A phenomenological model is presented that relates free-stream turbulence to the augmentation of stagnation-point surface flux quantities. The model requires the turbulence intensity, the longitudinal scale of the turbulence, and the energy spectra as inputs for the unsteady velocity at the edge of the near-wall viscous region. The form of the edge velocity contains both pulsations of the incoming flow and oscillations of the streamline. Incompressible results using a single fluctuating component are presented within the stagnation region of a two-dimensional cylinder. The time-averaged Froessling number is determined from the computations. These predictions are compared to existing incompressible experimental data. Additionally, the variations in the surface flux quantities with the longitudinal scale of the incoming free-stream turbulence, the Reynolds number, and the free-stream turbulence intensity are considered.
Beyond the Call of Duty: Compelling Health Care Professionals to Work During an Influenza Pandemic

In anticipation of pandemics and other mass disasters, several states have enacted little-known laws that authorize government officials to order health care professionals to work during declared public health emergencies, even when doing so would pose life-threatening risks. Health care professionals who violate these orders could face substantial penalties, ranging from license revocations to fines and imprisonment. The penalties would apply even to individuals whose jobs do not normally involve clinical responsibilities, as well as to health care professionals who are retired or taking time off from work to care for their families. This Article argues that these laws impose burdens that exceed the ethical commitments individuals make when they accept a professional license. In so doing, they compel health care professionals to engage in what is normally considered supererogatory behavior -- i.e., acts that are commendable if done voluntarily, but that go beyond what is expected. In making this argument, the Article rejects commonly-made assertions about health care professionals' ethical obligations, including the claim that health care professionals assumed the risk of infection; that a social contract requires health care professionals to work despite potential health risks; and that individuals who have urgently-needed skills have an obligation to use them. It concludes that, while health care professionals can legitimately be sanctioned for violating voluntarily-assumed employment or contractual agreements, they should not be compelled to assume life-threatening risks based solely on their status as licensed professionals. In place of singling out health care professionals for punitive measures, the Article argues that policy-makers should institute mechanisms to promote volunteerism.
MCDOSE — A Monte Carlo Dose Calculation Tool for Radiation Therapy Treatment Planning

MCDOSE is an EGS4 [1] user code developed at Stanford University for radiation therapy treatment planning dose calculations. MCDOSE can be used to simulate the transport of photons and electrons in a patient geometry built from CT data. Realistic clinical accelerator beams can be used for any combinations of gantry angles, couch angles, collimator rotations, source skin distances (SSD) and beam modifiers. MCDOSE can be used to compute dose distributions for conventional treatment with photon and electron beams, beamlet distributions for inverse treatment planning, and the final dose distributions for intensity modulated radiotherapy (IMRT) using the multileaf collimator (MLC) leaf sequences generated by a treatment planning optimization system. The MCDOSE code has been implemented for clinical dose verification and treatment planning at Stanford since the end of 1998 [2].
Chlorinated biphenyl induction of aryl hydrocarbon hydroxylase activity: a study of the structure-activity relationship.

Of 16 halogenated biphenyls examined for their capacity to induce hepatic aryl hydrocarbon hydroxylase activity in the chicken embryo, only three congeners, 3,4,39,49-tetrachlorobiphenyl, 3,4,5,39,49,59-hexachlorobiphenyl, and 3,4,5,39,49,59-hexabromobiphenyl, were active. They were approximately equipotent in the chicken embryo, with ED50 values of approximately 90 nmoles/kg. These three chlorobiphenyl congeners also induced hepatic aryl hydrocarbon hydroxylase activity in C57BL/6J mice and rats, and they competitively bound the hepatic cytosol binding species thought to be the receptor for the induction of this enzyme. Among the halogenated biphenyls, there appear to be two structural requirements for induction of aryl hydrocarbon hydroxylase activity: the presence of at least 2 adjacent halogen atoms in the lateral positions of each benzene ring (positions 3,4,39,49 or 3,4,5,39,49,59) and the absence of halogen atoms adjacent to the biphenyl bridge (positions 2,6,29, and 69); such substitutions lead to marked nonplanarity of the molecule. The halobiphenyl congeners that induced aryl hydrocarbon hydroxylase activity did not induce aminopyrine N-demethylase activity (a measure of phenobarbital-like activity); however, some of the congeners that failed to induce aryl hydrocarbon hydroxylase activity did induce aminopyrine N-demethylase. This suggests that while the commercial mixture of chlorobiphenyls, Aroclor 1254, induces a mixed pattern of microsomal monooxygenase activity resembling the combined administration of 3-methylcholanthrene and phenobarbital, any given chlorobiphenyl congener appears to produce only a 3-methylcholanthrene-like or a phenobarbital-like response (or the congener may be devoid of both activities). 3,4,39,49-Tetrachlorobiphenyl, the prototype of the halobiphenyls that induce hepatic aryl hydrocarbon hydroxylase activity, is an approximate isostereomer of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,7,8-tetrachlorodibenzofuran, and 3,4,39,49-tetrachloroazoxybenzene, all of which induce hepatic aryl hydrocarbon hydroxylase activity but which are over 100-fold more potent. Conversion of 3,4,39,49-tetrachlorobiphenyl to a more rigid, planar analogue, 2,3,6,7-tetrachlorobiphenylene, produced a compound roughly equipotent to TCDD in inducing hepatic aryl hydrocarbon hydroxylase activity in the chicken embryo.
Fully Parallel Stochastic Security-Constrained Unit Commitment

The increasing size and complexity of modern power systems and the integration of volatile renewable energy bring great challenges to the existing security-constrained unit commitment (SCUC) solution engines. This paper presents a fully parallel stochastic SCUC approach to obtain an efficient and fast solution for a large-scale power system with wind energy uncertainty. Variables duplication and auxiliary problem principle (APP) techniques are adopted to fully decompose the original stochastic optimization problem into three major solution modules: the unit commitment (UC) module solves multiple single UC problems; the optimal power flow (OPF) module handles multiple hourly DC-OPF problems; and the bridge module builds a connection between the UC and OPF modules. These three modules are conducted for both base case and scenarios, and can be totally solved in a parallel manner. Numerical case studies on a modified IEEE 118-bus system and a practical 1168-bus system demonstrate the effectiveness and efficiency of the proposed approach which will offer the power system a secure and economic operation under various uncertainties.
Glenohumeral kinematics after soft tissue interposition graft and glenoid reaming: A cadaveric study

Background: The management of young patients with glenohumeral arthritis is controversial. Resurfacing of the glenoid with biologic interposition and reaming of the glenoid have been suggested as potential treatment options. The goal of this study was to determine the change in glenohumeral contact pressures in interposition arthroplasty, as well as glenoid reaming in an arthritis model. We hypothesized that interposition with meniscal allograft will lead to the best normalization of contact pressure throughout the glenohumeral range of motion. Materials and Methods: Eight fresh-frozen cadaveric shoulders were tested in static positions of humeral abduction with a compressive load. Glenohumeral contact area, contact pressure, and peak force were determined sequentially for (1) intact glenoid (2) glenoid with cartilage removed (arthritis model) (3) placement of lateral meniscus allograft (4) placement of Achilles allograft (5) arthritis model with reamed glenoid. Results: The arthritis model demonstrated statistically higher peak pressures than intact glenoid and glenoid with interpositional allograft. Meniscal and Achilles allograft lowered mean contact pressure and increased contact area to a level equal to or more favorable than the control state. In contrast, the reamed glenoid did not show any statistical difference from the arthritis model for any of the recorded measures. Conclusion: Glenohumeral contact pressure is significantly improved with interposition of allograft at time zero compared to an arthritic state. Our findings suggest that concentric reaming did not differ from the arthritic model when compared to normal. These findings favor the use of allograft for interposition as a potential treatment option in patients with glenoid wear.
Design of a multi-band polarization stacked microstrip antenna used in satellite navigation

A novel multi-band circular polarization stacked microstrip antenna used in three kinds of satellite navigation systems is designed.It has been realized by three stacked patches,which are fed by two and four pins.The amplitude and phase relationship between the two and four pins to maintain circular polarization is obtained by wide band Wilkinson 90° and 180° hybrid coupler.The antenna can work at GPS L1 and L5 bands,Beidou No.1 S band,Beidou No.2 B1 and B2 bands and Galileo E5 and E2-L1-E1 bands.The simulation of the layout results show that this antenna has good circular polarization characteristic,the S11 characteristic is less than-10 dB in the whole operation bands.
Removal of visceral fat prevents insulin resistance and glucose intolerance of aging: An adipokine-mediated process?

Age-dependent changes in insulin action and body fat distribution are risk factors for the development of type 2 diabetes. To examine whether the accumulation of visceral fat (VF) could play a direct role in the pathophysiology of insulin resistance and type 2 diabetes, we monitored insulin action, glucose tolerance, and the expression of adipo-derived peptides after surgical removal of VF in aging (20-month-old) F344/Brown Norway (FBN) and in Zucker Diabetic Fatty (ZDF) rats. As expected, peripheral and hepatic insulin action were markedly impaired in aging FBN rats, and extraction of VF (accounting for approximately 18% of their total body fat) was sufficient to restore peripheral and hepatic insulin action to the levels of young rats. When examined at the mechanistic level, removal of VF in ZDF rats prevented the progressive decrease in insulin action and delayed the onset of diabetes, but VF extraction did not alter plasma free fatty acid levels. However, the expression of tumor necrosis factor-alpha and leptin in subcutaneous (SC) adipose tissue were markedly decreased after VF removal (by approximately three- and twofold, respectively). Finally, extracted VF retained approximately 15-fold higher resistin mRNA compared with SC fat. Our data suggest that insulin resistance and the development of diabetes can be significantly reduced in aging rats by preventing the age-dependent accumulation of VF. This study documents a cause-and-effect relationship between VF and major components of the metabolic syndrome.
Desirable Difficulty and Other Predictors of Effective Item Orderings.

Online adaptive tutoring systems are increasingly being used in classrooms as a way to provide guided learning for students. Such tutors have the potential to provide tailored feedback based on specific student needs and misunderstandings. Bayesian knowledge tracing (BKT) is used to model student knowledge when knowledge is assumed to be changing throughout a single assessment period. The basic BKT model assumes that the chance a student transitions from ”not knowing”to ”knowing”after each item is the same, with each item in the tutor considered a learning opportunity. It could be the case, however, that learning is actually context sensitive; context in our analysis is the order in which the items were administered. In this paper, we use BKT models to find such context sensitive transition probabilities in a mathematics tutoring system and offer a methodology to test the significance of our model based findings. We employ cross validation techniques to find models where including item ordering context improves predictive capability compared to the base BKT models. We then use regression testing to try to find features that may predict the effectiveness of an item ordering.
An Efficient Exponential Directional Iterative Differencing Scheme for Three-Dimensional Sn Computations in XYZ Geometry

A new exponential spatial differencing scheme based on zeroth spatial transport moments, the exponential directional iterative (EDI) S n scheme for three-dimensional (3-D) Cartesian geometry, is presented. The EDI scheme is a logical extension of the positive, efficient exponential directional weighted (EDW) method used in the PENTRAN parallel S n solver in an adaptive differencing strategy. The EDI scheme uses EDW-rendered exponential coefficients as initial values to begin a fixed-point iteration to refine exponential coefficients. Iterative refinement of these coefficients typically converged in fewer than four fixed-point iterations per ordinate, and yielded more accurate angular fluxes compared to other schemes tested. Overall, the EDI scheme is an order of magnitude more accurate than EDW, and two orders of magnitude more accurate than the legacy diamond zero (DZ) scheme for a given mesh. EDI is therefore a good candidate for a fourth-level scheme in the PENTRAN adaptive sequence. The 3-D Cartesian computational cost of EDI was ∼20% more than EDW, and only ∼40% more than DZ. Thus, EDI renders increased accuracy using zeroth spatial transport moments in a straightforward manner for any 3-D Cartesian code. More evaluation is ongoing to determine suitability in an upgraded adaptive differencing sequence algorithm in PENTRAN.
Monitoring driver cognitive load using functional near infrared spectroscopy in partially autonomous cars

In partially automated cars, it is vital to understand the driver state, especially the driver's cognitive load. This might indicate whether the driver is alert or distracted, and if the car can safely transfer control of driving. In order to better understand the relationship between cognitive load and the driver performance in a partially autonomous vehicle, functional near infrared spectroscopy (fNIRS) measures were employed to study the activation of the prefrontal cortex of drivers in a simulated environment. We studied a total of 14 participants while they drove a partially autonomous car and performed common secondary tasks. We observed that when participants were asked to monitor the driving of an autonomous car they had low cognitive load compared to when the same participants were asked to perform a secondary reading or video watching task on a brought in device. This observation was in line with the increased drowsy behavior observed during intervals of autonomous system monitoring in previous studies. Results demonstrate that fNIRS signals from prefrontal cortex indicate additional cognitive load during manual driving compared to autonomous. Such brain function metrics could be used with minimally intrusive and low cost sensors to enable real-time assessment of driver state in future autonomous vehicles to improve safety and efficacy of transfer of control.
Steadfastness, deference, and permissive rationality

Recently, Levinstein (Philos Phenomenol Res, 2015) has offered two interesting arguments concerning epistemic norms and epistemic peer disagreement. In his first argument, Levinstein claims that a tension between Permissivism and steadfast attitudes in the face of epistemic peer disagreement generally leads us to conciliatory attitudes; in his second argument, he argues that, given an ‘extremely weak version of a deference principle,’ Permissivism collapses into Uniqueness. However, in this paper, I show that when we clearly distinguish among several types of Permissivism (what I call Permissivism\(_{1}\), Permissivism\(_{2}\), and Permissivism\(_{3}\)), we can see that any type of Permissivism fits well with steadfast attitudes. Further, even though Levinstein’s ‘extremely weak version of a deference principle’ does rule out a possibility for some types of Permissivism (Permissivism\(_{1}\) and Permissivism\(_{2}\)), it is still compatible with the other type of Permissivism (Permissivism\(_{3}\)), so we may regard at least that version of a deference principle as a viable position in connection with that particular type of permissive rationality.