cssi/SciSciGPT-SciSciNet huggingface dataset:
Stem cell-based therapy for dry AMD

A macular degeneration (AMD) is the leading cause of blindness in people over age 55 in the U.S. and the developed world. AMD is a multifactorial disease and there is no adequate animal model that recapitulates key characteristics of dry AMD. The lack of a robust model for AMD is a major impediment for mechanistic studies and drug development. Consequently, effective treatments for AMD are not available, although vitamin supplementation is recommended and is modestly beneficial for a small population of patients. Therefore, the need for novel therapeutic and preventive strategies is pressing. Recent generation of RPE cells from embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), offers new promise for cell replacement therapy and disease modeling in AMD Modeling dry AMD in vitro could be an invaluable tool to study cellular and molecular mechanisms underlying AMD and to screen for compounds that reverse pathologic features, as a step towards drug development. Nonetheless, a reprogrammingbased model of AMD would need to take genetic, environmental and epigenetic factors into consideration to reproduce a physiologically relevant in vitro model. In addition, successful cell-based therapy in dry AMD requires: 1) generation of patient-specific bona fide RPE cells that are morphologically and physiologically similar to native RPE, 2) RPE monolayer on a biodegradable matrix that allows transplantation of an intact epithelium. An intact structure of the RPE monolayer cultured on a biodegradable matrix not only facilitates transplantation into the sub-retinal space but also is crucial for RPE survival, cellular function and integration in the host retina.
Changes in Climate, Forest Phenology, and Forest Disturbances Around Western Lake Superior

This work proceeds from two hypotheses. First, we can explain much of the observed seasonal and year-to-year variability in forest phenology using weather and climate observations. Seasonal forest phenology is driven by the progress of the warm season: it is observed that frost events can stop spring growth and that seasonal droughts can degrade forest health. What we donâ€™t quite know yet is how strong the roles of climate change and weather variability are in these processes. Second, linking anomalies in observed phenology (by remote sensing methods) with climatological analyses can indicate the occurrence, extent, and possible causes of forest disturbances. We pursue two primary interests here: (1) observations of regional climatology and its variability in the area around western Lake Superior, and (2) identifying the influence of climate variability on forest phenology and disturbances in that area.
Uncertainty in Steady-State Diagnostics of a Current-Pressure Transducer: How Confident are We in Diagnosing Faults?

Current-Pressure (I/P) transducers are effective pressure regulators that can vary the output pressure depending on the supplied electrical current signal, and are commonly used in pneumatic actuators and valves. Faults in current-pressure transducers have a significant impact on the regulation mechanism, and therefore, it is important to perform diagnosis to identify such faults. However, there are different sources of uncertainty that significantly affect the diagnostics procedure, and therefore, it may not be possible to perform fault diagnosis and prognosis accurately, with complete confidence. These sources of uncertainty include natural variability, sensor errors (gain, bias, noise), model uncertainty, etc. This paper presents a computational methodology to quantify the uncertainty and thereby estimate the confidence in the fault diagnosis of a current-pressure transducer. First, experiments are conducted to study the nominal and off-nominal behavior of the I/P transducer; however, sensor measurements are not fast enough to capture brief transient states that are indicative of wear, and hence, steady-state measurements are directly used for fault diagnosis. Second, the results of these experiments are used to train a Gaussian process model using machine learning principles. Finally, a Bayesian inference methodology is developed to quantify the uncertainty and assess the confidence in fault diagnosis by systematically accounting for the aforementioned sources of uncertainty.
Expression of Lipoxygenase Isozymes in Soybean Tissues

Lipoxygenases (E.C. 1.13.11.12) catalyze the peroxidation of compounds that possess a cis, cis-1 ,4-pentadiene structure. Their principal substrates in higher plants are the di- and tri-unsaturated fatty acids, linoleic (C18 : 2) and linolenic (Cl8: 3) acids. Lipoxygenases (LOXs) are also known to catalyze the cooxidation of chlorophylls and carotenoids (Axelrod et al, 1987; Vick and Zimmermann, 1987).
Fe-S and Mo-Fe-S clusters as models for the active site of nitrogenase

Studies on the enzyme nitrogenase have shown that it contains two novel metal-sulfur clusters: the iron-molybdenum cofactor (FeMo-co), which contains one Mo, 6–7 Fe, and ∼ 4 S atoms in a spincoupled paramagnetic (S=3/2) cluster; and the P clusters, variants of normal but highly reduced 4 Fe-4 S clusters in which three Fe atoms are somehow distinguished from the fourth and which, when oxidized, exhibit an usually high spin (S=5/2 or 7/2) ground state. No structures consistent with all available spectroscopic data have been proposed for either unit. Synthetic efforts aimed at developing models for FeMo-co have utilized tetrathiomolybdate as starting material, and have resulted in two well-characterized classes of Mo-Fe-S cluster: those containing the MoFe3S4 “cubane” core and those containing a “linear” MoS2Fe unit. The former apparently contain Mo in a relatively reduced valence state (ca. + 3) and exhibit Mo-S and Mo-Fe distances in good agreement with those found for the Mo site of nitrogenase; the latter contain Mo in a higher oxidation state (ca. + 6) and have significantly shorter Mo-S distances. Synthetic work related to the P clusters has centered on the properties of the [Fe4S4(SR)4]3− ions, for which two different structures with different magnetic properties are found, and on the properties of 4 Fe-4 S clusters with non-thiolate ligands.
Preserving the Incumbent Users’ Location Privacy in the 3.5 GHz Band

In dynamic spectrum sharing (DSS) ecosystem with non-informing incumbent users (IUs), Environmental Sensing Capability (ESC) system has been proposed to detect IU activity information for a geolocation database-driven spectrum access system (SAS). SAS then allocates unused spectrum left by IUs to secondary users (SUs). However, IU location information is often highly sensitive and thus it is preferable to avoid storing ESC sensing data on a SAS, especially if the SAS is a potential target of cyber attacks. None of existing works studied the IU location privacy protection problem in such an ESC-based dynamic spectrum access (DSA) system. In this paper, we fill in the void by proposing novel privacy-preserving ESC-based dynamic spectrum access (PriDSA) schemes. We designed two versions of PriDSA that preserve IU privacy to different extent under two different adversary models, namely non-colluding honest but curious SAS model and colluding malicious SAS model. Evaluation results show that PriDSA is efficient in terms of communication and computation overhead and accurately serves SU spectrum access requests while preserving location privacy of IUs.
Decellularization techniques and their applications for the repair and regeneration of the nervous system

A variety of surgical and non-surgical approaches have been used to address the impacts of nervous system injuries, which can lead to either impairment or a complete loss of function for affected patients. The inherent ability of nervous tissues to repair and/or regenerate is dampened due to irreversible changes that occur within the tissue remodeling microenvironment following injury. Specifically, dysregulation of the extracellular matrix (i.e., scarring) has been suggested as one of the major factors that can directly impair normal cell function and could significantly alter the regenerative potential of these tissues. A number of tissue engineering and regenerative medicine-based approaches have been suggested to intervene in the process of remodeling which occurs following injury. Decellularization has become an increasingly popular technique used to obtain acellular scaffolds, and their derivatives (hydrogels, etc.), which retain tissue-specific components, including critical structural and functional proteins. These advantageous characteristics make this approach an intriguing option for creating materials capable of stimulating the sensitive repair mechanisms associated with nervous system injuries. Over the past decade, several diverse decellularization methods have been implemented specifically for nervous system applications in an attempt to carefully remove cellular content while preserving tissue morphology and composition. Each application-based decellularized ECM product requires carefully designed treatments that preserve the unique biochemical signatures associated within each tissue type to stimulate the repair of brain, spinal cord, and peripheral nerve tissues. Herein, we review the decellularization techniques that have been applied to create biomaterials with the potential to promote the repair and regeneration of tissues within the central and peripheral nervous system.
Prevalence of Post-Traumatic Stress Disorder in Emergency Physicians in the United States

Author(s): DeLucia, Joseph A.; Bitter, Cindy; Fitzgerald, Jennifer; Greenberg, Miggie; Dalwari, Preeti; Buchanan, Paula | Abstract: Introduction: There is increasing concern about the effects of occupational stressors on thewellness of healthcare providers. Given high patient acuity, circadian rhythm disruption, andother workplace stressors, emergency physicians (EP) would be predicted to have high rates ofoccupational stress. We conducted this study to assess the prevalence of post-traumatic stressdisorder (PTSD) in attending EPs practicing in the United States.Methods: A link to an electronic questionnaire was distributed through the emergency medicinecentricpublication Emergency Medicine News. We compared the prevalence of PTSD in EPs tothe general population using a chi-square goodness of fit test, and performed logistic regression toassess for significance of risk factors.Results: We received survey responses from 526 persons. In this study, EPs had a PTSD pointprevalence of 15.8%. Being a victim of a prior trauma or abuse is the primary predictor of PTSD(odds ratio [OR] [95% confidence interval {CI}, 2.16 (1.21 – 3.86)], p = 0.009) and PTSD severityscore (OR [95% CI, 1.16 (1.07 – 1.26)], p l0.001).Conclusion: Emergency physicians have a substantial burden of PTSD, potentially jeopardizingtheir own health and career longevity. Future studies should focus on identifying subgroups at higherrisk for PTSD and modifiable risk factors. Prevention and treatment strategies should be developedand tested in healthcare providers.
Associations among Early Exposure to Neighborhood Disorder, Fathers' Early Involvement, and Children's Internalizing and Externalizing Problems.

This study aimed to examine (1) the effects of early exposure to neighborhood disorder and fathers’ early involvement on children’s long-term internalizing and externalizing problems, and (2) wheth...
Unstageable Pressure Injuries: Identification, Treatment, and Outcomes Among Critical Care Patients.

Unstageable pressure injuries are widely understood to be full-thickness pressure injuries in which the base is obscured by slough and/or eschar. Correct identification of these pressure injuries can be challenging among health care professionals and, although treatments vary, debridement is key. Although the available research on unstageable pressure injuries is growing, there still is considerable need for advancements in the science regarding identification, treatment, and outcomes in critical care patients.
Corporate Beneficence and COVID-19:

This article explores the motives underlying corporate responses to the COVID-19 pandemic. The analysis begins with Thomas Dunfee’s Statement of Minimum Moral Obligation (SMMO), which specifies, mo...
Provider perceptions of extended venous thromboembolism prophylaxis for hospitalized medically ill patients

Abstract Background Almost one-fourth of medically ill patients may remain at risk for venous thromboembolism (VTE) following hospital discharge, yet few receive extended-duration VTE prophylaxis. Methods This qualitative study at a single academic medical center assessed hospitalists’ perceptions of and barriers to implementation of extended-duration VTE prophylaxis following hospital discharge for the medically ill with the purpose of generating topics and hypotheses for future study. A focus group was conducted using semi-structured facilitator template to guide the discussion. Anonymous verbatim data transcribed from focus group participants were summarized using thematic analysis. Results Fifteen hospitalist providers at University of Utah Hospital participated in this focus group. Themes uncovered during the session included perceived low burden of post-hospitalization VTE; lack of compelling evidence supporting the net clinical benefit of extended-duration prophylaxis; concern for high medication cost; practical uncertainty about prescribing extended-duration prophylaxis; and added risk of complications (bleeding events, transitions of care confusion, polypharmacy). Conclusions This group of providers believed post-hospitalization VTE risk in the medically ill is not sufficiently high to justify potential risks of extended-duration VTE prophylaxis and that a strong case for net clinical benefit and cost-effectiveness has not been made. These qualitative data are hypothesis-generating and future research should clearly define and quantify the timing and risk of VTE following hospitalization for medical illness in a real-world population, validate practical VTE and bleeding risk stratification schema, and explore cost-effectiveness of extended-duration prophylaxis. Ultimately, providers seek a clear message of which patients derive net clinical benefit from extended-duration VTE prophylaxis.
Towards developing areawide semiochemical‐mediated, behaviorally‐based integrated pest management programs for stored product insects

With less emphasis on fumigation after harvest, due to the phase-out of methyl bromide and increasing phosphine resistance, diversified postharvest integrated pest management (IPM) programs are needed. Here, we synthesize knowledge on semiochemical-mediated, behaviorally-based tactics, wherein semiochemicals are deployed to manipulate pest behavior to protect commodities. We note that beyond monitoring, commercial use is limited to mating disruption targeting mostly moths. In total, behaviorally-based tactics have been attempted for eight species of stored product insects from two orders and six families. Eighteen challenges were identified that may have prevented robust implementation of semiochemicals for behaviorally-based management in stored products, including direct competition with ubiquitous food cues, and the diverse insect assemblages that colonize food facilities. Further, we discuss the scientific data and methods required to support stakeholder acceptance of semiochemicals at food facilities, including demonstrating that pests are not attracted from the landscape and minimal spillover around pheromones. We sketch a robust areawide behaviorally-based IPM program after harvest, and clarify properties for improving semiochemicals, including incorporating those that are broad spectrum, competitive with food cues, potent at low concentration, and exhibit dose-dependent attraction. The research gaps and testable hypotheses described here will speed developing behaviorally-based tactics at food facilities. © 2021 Society of Chemical Industry.
All It Takes Is One Click to Join Me on a "Meet": The Positive Impact of Technology on Peer Observations in the Virtual Learning Environment

Physically stepping foot into the middle and high school classroom is the opportunity teacher candidates (TCs) most look forward to as they enter their final year in our middle and secondary teacher preparation program. It is in this internship year when TCs practice the theory they have learned and start making their own pedagogical choices. The internship year and its experiences are recognized by AMLE Standard 1: "Middle level teacher candidates understand, use, and reflect on the major concepts, principles, theories, and research related to young adolescent development and use that knowledge in their practice" (AMLE, 2012). The question I faced with the arrival of COVID-19 and the shutdown of in-person school this past spring and fall as a teacher educator (TE) was this: How will I be able to provide these valuable moments of professional growth for my TCs if they are not in the buildings? The following description presents fellow teacher educators with my response to this question. I describe the creation of virtual peer observation experiences and in-real-time coaching that occurred in the virtual internship. Additionally, I describe the impact this process had on virtual post-observation conferences.
Fomite Transmission, Physicochemical Origin of Virus-Surface Interactions, and Disinfection Strategies for Enveloped Viruses with Applications to SARS-CoV-2

Inanimate objects or surfaces contaminated with infectious agents, referred to as fomites, play an important role in the spread of viruses, including SARS-CoV-2, the virus responsible for the COVID-19 pandemic. The long persistence of viruses (hours to days) on surfaces calls for an urgent need for effective surface disinfection strategies to intercept virus transmission and the spread of diseases. Elucidating the physicochemical processes and surface science underlying the adsorption and transfer of virus between surfaces, as well as their inactivation, is important for understanding how diseases are transmitted and for developing effective intervention strategies. This review summarizes the current knowledge and underlying physicochemical processes of virus transmission, in particular via fomites, and common disinfection approaches. Gaps in knowledge and the areas in need of further research are also identified. The review focuses on SARS-CoV-2, but discussion of related viruses is included to provide a more comprehensive review given that much remains unknown about SARS-CoV-2. Our aim is that this review will provide a broad survey of the issues involved in fomite transmission and intervention to a wide range of readers to better enable them to take on the open research challenges.
Addressing the Mental and Emotional Health Impacts of COVID-19 on Children and Adolescents: Lessons From HIV/AIDS

The COVID-19 pandemic has led to lasting mental health and psychosocial consequences just as were experienced with the HIV epidemic. A rapid review of published systematic reviews on HIV/AIDS and mental health outcomes and responses among children and adolescents was used to identify lessons for the COVID-19 pandemic response. The review found that HIV/AIDS responses to promote mental health, prevent ill-health and treat mental health conditions included diverse interventions at the structural or national, community, household and individual levels. Some of these responses can be easily replicated, others require substantial adaptation, and some can inform development of new innovative offline and online responses to mitigate impact of COVID-19 on mental health of children and adolescents. Programs that mitigate economic impacts including child grants, income generating activities for caregivers, food distribution, health care vouchers, and other economic empowerment interventions can be replicated with minor adjustments. Helplines for vulnerable or abused children and shelters for victims of gender-based violence can be scaled up to respond to the COVID pandemic, with minimal adaptation to adhere to prevention of contagion. Mass media campaigns to combat stigma and discrimination were successfully employed in the HIV response, and similar interventions could be developed and applied in the COVID context. Some programs will need more substantial adjustments. In health facilities, mainstreaming child-sensitive mental health training of frontline workers and task sharing/shifting to community volunteers and social workers as was done for HIV with community health workers, could advance mental illness detection, particularly among abuse victims, but requires adaptation of protocols. At the community and household levels, expansion of parenting programs can help caregivers navigate negative mental health effects on children, however, these are not often operating at scale, nor well-linked to services. Programs requiring innovation include converting adolescent and youth safe physical spaces into virtual spaces particularly for at-risk girls and young women; organizing virtual community support groups, conversations, and developing online resources. Re-opening of schools and introduction of health and hygiene policies, provides another opportunity for innovation - to provide mental health and psychosocial support to all children as a standard package of care and practice.
Ordered hexagonal columnar liquid crystalline self-assembly of mesogen-free sulfonylated side-chain chiral polyethers and their high dielectric property

Abstract To achieve large spontaneous polarization for ferroelectric liquid crystalline polymers, we have designed a series of mesogen-free isotactic polyethers with sulfonylated side chains. Different from prior studies using linear alkyl side chains, in this work a methyl branch was implemented in the alkyl side chains of the chiral polyethers. As a result of the continuous twist from the methyl branches and strong dipole-dipole interactions among neighboring sulfonyl groups, a helical chain conformation with tilted side chains was achieved. When the branched side chains were short (e.g., C5) and double chirality existed in both the main chain and side chains, a crystalline structure was obtained. When the branched side chains were long (e.g., ≥ C8) and single chirality existed in the main chain, an ordered hexagonal columnar liquid crystalline phase was induced. Their high-field dielectric property was studied by electric displacement-electric field (D-E) loop tests; however, no ferroelectric behavior was observed up to 200 MV/m. It was considered that the dipole-dipole interaction among neighboring sulfonyl groups in the helical chains was too strong to allow easy ferroelectric flipping.
Transient safety evaluation of the heat pipe microreactor – Potential energy source for hydrogen production

Abstract Recently, microreactor designs have been receiving significant attention in the nuclear industry due to their potential advantages in certain applications. These nuclear reactor designs have been considered to provide reliable and sustainable power for on-site installation and operation. Microreactors may be utilized to provide heat and power to hydrogen production, remote communities, and industrial facilities such as military installations, disaster relief zones, and are being considered for underwater and deep space operation as well. However, these designs and concepts remain largely untested and unproven in the commercial industry. Further research and development are still required to prove microreactor designs are safe and reliable for commercial use. Different cooling technologies have been taken into consideration for microreactor concepts since the 1960s, mainly for federal space reactor projects such as LEGOLRCS, HOMER, and KRUSTY. This work provides thermal hydraulics and analysis for the Idaho National Laboratory's MAGNET (Micro-reactor Agile Non-nuclear Experimental Testbed) facility. The MAGNET facility is currently being developed to duplicate a microreactor design using heat pipe cooling technology. Our main goal is to examine the response of the test facility under steady-state and transient operation conditions. We constructed our own estimated model of the MAGNET geometry using a software coupling method made up of MOOSE/SAM software systems. The steady state results of this work have been published in a former article. The new results mainly focus on the transient states. By communicating with the Idaho National Laboratories, we upgraded the geometry of MAGNET heat pipes. This not only verifies the design of the facility under such conditions but also benchmarks the modeling capability of the MOOSE/SAM code system that can be potentially used to model other microreactor concepts in the future.
Structure-Function Relationships of TMJ Lateral Capsule-Ligament Complex

Abstract The human temporomandibular joint (TMJ) lateral capsule ligament (LCL) complex is debated as a fibrous capsule with distinct ligaments or ligamentous thickening, necessitating further evaluation of the complex and its role in TMJ anatomy and mechanics. This study explores the ultrastructural arrangement, biomechanical tensile properties, and biochemical composition of the human LCL complex including region-specific differences to explore the presence of a distinct temporomandibular ligament and sex-specific differences to inform evaluations of potential etiological mechanisms. LCL complex ultrastructural arrangement, biomechanical properties, and biochemical composition were determined using cadaveric samples. Statistical modeling assessed sex- and region-specific effects on LCL complex tissue properties. Collagen fiber coherency, collagen fiber bundle size, and elastin fiber count did not differ between sexes, but females trended higher in elastin fiber count. LCL complex water and sGAG content did not differ between sexes or regions, but collagen content was higher in the anterior region (311.0±185.6 μg/mg) compared to the posterior region (221.0±124.9 μg/mg) (p=0.045) across sexes and in males (339.6±170.6 μg/mg) compared to females (204.5±130.7 μg/mg) (p=0.006) across regions. Anterior failure stress (1.1±0.7 MPa) was larger than posterior failure stress (0.6±0.4 MPa) (p=0.024). Regional differences confirm the presence of a mechanically and compositionally distinct temporomandibular ligament. Baseline sex-specific differences are critical for etiological investigations of sex disparities in TMJ disorders. These results have important biomechanical and clinical ramifications, providing critical baseline tissue material properties, informing the development of TMJ musculoskeletal models, and identifying new areas for etiologic investigations for temporomandibular disorders.
Interpretive Methods: Micromethods

Recent developments in qualitative research are analyzed. Qualitative inquiry is located within an interdisciplinary and historical framework. The uses and forms of qualitative inquiry are reviewed, including those forms associated with participative, action research. Speculations on the future of interpretive, mirco-methods are offered.
ON THE EXISTENCE OF THE ENDOGENOUS MORTGAGE RATE PROCESS

The mortgage rate is a major factor in the refinancing decision. The refinancing behavior influences cash flow and, therefore, mortgage price. The prices of mortgage instruments drives the mortgage rates. We consider a problem of the existence of a dynamic mortgage rate process which resolves this circular dependence. The existence is proved by constructing a solution using a newly proposed level set method.
Operating system support for augmented reality applications

Augmented reality (AR) takes natural user input (NUI), such as gestures, voice, and eye gaze, and produces digital visual overlays on top of reality seen by a user. Today, multiple shipping AR applications exist, most notably titles for the Microsoft Kinect and smartphone applications such as Layar, Wikitude, and Junaio. Despite this activity, little attention has been paid to operating system support for AR applications. Instead, each AR application today does its own sensing and rendering, with the help of user-level libraries like OpenCV or the Microsoft Kinect SDK. In this paper, we explore how operating systems should evolve to support AR applications. Because AR applications work with fundamentally new inputs and outputs, an OS that supports AR applications needs to re-think the input and display abstractions exposed to applications. Unlike mouse and keyboard, which form explicit, separate channels for user input, NUI requires continuous sensing of the real-world environment, which often has sensitive data mixed with user input. Hence, the OS input abstractions must ensure that user privacy is not violated, and the OS must provide a fine-grained permission system for access to recognized objects like a user's face and skeleton. In addition, because visual outputs of AR applications mix real-world and virtual objects, the synthetic window abstraction in traditional GUIs is no longer viable, and OSes must rethink the display abstractions and their management. We discuss research directions for solving these and other issues and building an OS that let multiple applications share one (augmented) reality.
The evolutionary history of Darwin's finches: speciation, gene flow, and introgression in a fragmented landscape.

Many classic examples of adaptive radiations take place within fragmented systems such as islands or mountains, but the roles of mosaic landscapes and variable gene flow in facilitating species diversification is poorly understood. Here we combine phylogenetic and landscape genetic approaches to understand diversification in Darwin's finches, a model adaptive radiation. We combined sequence data from 14 nuclear introns, mitochondrial markers, and microsatellite variation from 51 populations of all 15 recognized species. Phylogenetic species-trees recovered seven major finch clades: ground, tree, vegetarian, Cocos Island, grey and green warbler finches, and a distinct clade of sharp-beaked ground finches (Geospiza cf. difficilis) basal to all ground and tree finches. The ground and tree finch clades lack species-level phylogenetic structure. Interisland gene flow and interspecies introgression vary geographically in predictable ways. First, several species exhibit concordant patterns of population divergence across the channel separating the Galapagos platform islands from the separate volcanic province of northern islands. Second, peripheral islands have more admixed populations while central islands maintain more distinct species boundaries. This landscape perspective highlights a likely role for isolation of peripheral populations in initial divergence, and demonstrates that peripheral populations may maintain genetic diversity through outbreeding during the initial stages of speciation.
Capturing the effects of free surfaces on void strengthening with dislocation dynamics

Abstract Void strengthening in crystalline materials refers to the increase in yield stress due to the impediment of dislocation motion by voids. Dislocation dynamics (DD) is a modeling method well suited to capture the physics, length scales, and time scales associated with void strengthening. However, previous DD simulation of dislocation–void interactions have been unable to accurately account for the strong image forces acting on the dislocation due to the void’s free surface. In this article, we employ a finite-element-based DD method to determine the obstacle strength of voids, defined as the critical resolved shear stress for a dislocation to glide past an array of voids. Our results demonstrate that the attractive image forces between the dislocation and free surface significantly reduce the obstacle strength of voids. Effects of surface mobility and stress concentrations around the void are also explored and are shown to have minimal effect on the critical stress. Finally, a new model relating void size and spacing to obstacle strength is proposed.
A synthetic polypentapeptide of elastin for initiating calcification

A polypentapeptide (PPP) of tropoelastin having a repeating amino acid sequence of (Val-Pro-Gly-Val-Gly)n was evaluated for its potential to initiate in vivo calcification and to enhance bone formation in nonhealing calvarial wounds (8.0 mm) in 396 adult Walter Reed rats. There were four configurations of the PPP (molecular weight range of 50-100K dalton) consisting of 1-dry PPP; 2-coacervate PPP; 3-gamma irradiated, cross-linked PPP; 4-calcified, gamma irradiated, cross-linked PPP. These four iterations plus a control group of animals constituted the five treatment classes that were evaluated at days 1, 3, 7, 21, 42, and 147. Seventy two rats were used for each treatment and 36 rats for the control. Following euthanatization, specimens were placed into 70% ethanol, embedded in polymethyl methacrylate, sectioned at 3.5 micrometers, and alternating sections were stained with Masson-Goldner trichrome and von Kossa stains. Histomorphometric analysis was accomplished using a Zeiss Universal microscope (250 X) and Videoplan Image Analysis System to evaluate five random histologic fields from margin to margin of the craniotomy. Trabecular bony volume and area of calcification islands were quantitated. A Student's t test for unpaired data to determine treatment differences (within the same temporal groups) revealed that there was no significant difference between treatments and control for trabecular bony volume; however, there was a significant difference between experimentals and control for calcification islands (P less than 0.05) such that calcifications islands for the experimentals were greater than the control. There was not a significant difference between experimental treatments.(ABSTRACT TRUNCATED AT 250 WORDS)
Effects of lithium carbonate on sleep.

LITHIUM carbonate is now widely used for the treatment of mania,ls2 the prophylaxis of recurrent mania and depression2-4 and, to an extent, in the treatment of selected depressed patients. 5- 7 There is a clear trend towards the increased use of lithium for more patients and for longer periods of time.s Since depressed and manic patients have a significant sleep disturbance and. as it has been suggested that there may be significant associations between these sleep changes and both the clinical syndromes and the antidepressant drug effects,s-13 it seemed important to determine the effect of lithium on sleep (both acutely and chronically). Further, if lithium, which is now being used chronically for many patients, were to adversely affect sleep, then these patients may experience long-term sleep alterations of unknown implications. It is also of interest to determine what, if any, are the correlations between lithium’s therapeutic and prophylactic effects and its influence on the disturbed sleep pattern of these patients. Depressed patients (as a group) have a reduction in total sleep time, more awakenings during the night and less stage 4 sleep. 11, 14- 21 In addition, Mendels and Hawkins17,22 have reported that depressed patients take longer to fall asleep and wake significantly earlier in the morning and have increased amounts of stage 1 sleep. Reports on the amount of stage 1 REM sleep obtained by depressed patients are conflicting. Some studies report a reduction in REM sleep during depression, *I48 17* 20, 23-25 others report normal or even slightly increased REM sleep time with depression26p 27 with an earlier REM sleep onset1s,26 and an increase in phasic REM sleep elements such as eye movements. l s Later reports by MENDELS et aLa 2s* 3o likewise reflect a relatively high percentage of REM sleep as well as a pressure to achieve REM sleep in some (but not all) depressed patients. Two previous studies31* 32 of the effects of lithium carbonate on sleep offer apparently contradictory results, although the different findings may be a function of the dose administered and the subjects studied. BREBBIA et al. 31 administered 750 mg/24 hr lithium carbonate for 8 days to three control subjects and to three manic patients with plasma levels ranging between 0.34 and 0.46 mEq/l. The plasma levels are below those regarded as being in the therapeutic or prophylactic range. 2,8 They reported no uniform change in sleep pattern associated with the drug. KUPFER et al.,32 on the other hand, reported a significant increase in delta wave sleep (stages 3 and 4 combined) and a significant decrease in stage 1
Using an educational presentation to evaluate staffs' attitudes/perceptions regarding the use of mind/body interventions during serial MRIs for pediatric neuro-oncology patients

Abstract Pediatric neuro-oncology patients require serial MRI scans for years after diagnosis and medical treatment to monitor disease status. Managing anxiety and distress associated with MRI procedures is essential to improving the quality of the patient's repeated experience in radiology and ensuring the quality of the scan. Mind/body interventions such as relaxation, guided imagery, and hypnosis can be useful tools to facilitate MRI procedures. In a large pediatric radiology department, the investigators used an educational presentation regarding mind/body interventions and pre- and postpresentation surveys to evaluate staffs' attitudes and perceptions and to identify potential obstacles regarding the use of such interventions. A total of 49 radiology staff attended the educational presentation and completed the pre- and postpresentation surveys. Primary system obstacles to the use of mind/body interventions in radiology were identified as well as discipline differences regarding basic knowledge of mind/body interventions. A wide range of staff's attitudes and perceptions about mind/body interventions was recorded. Most participants reported finding the presentation "informative" and believed it would have a positive impact on their clinical work. In addition, based upon the study results, the investigators have developed and are piloting a screening measure to be used by nursing staff to facilitate proactive identification of patients in need of such interventions for subsequent scans. The investigators intend this study to serve as a template for nursing staff at other sites to evaluate staff perceptions and the need for mind/body interventions within their own radiology department.
Substitution of tenofovir/emtricitabine for Hepatitis B immune globulin prevents recurrence of Hepatitis B after liver transplantation

Background Hepatitis B immune globulin (HBIg) with or without nucleos(t)ide analogue (NA) inhibitors has been shown to prevent recurrence of hepatitis B virus (HBV) following orthotopic liver transplantation (OLT). However, the use of HBIg has many disadvantages. Aims The present study was performed to determine if converting patients from HBIg±NA to combination NA therapy could prevent recurrence of HBV. Methods Twenty-one recipients without evidence of HBV recurrence on HBIg±NA for ≥6 months were enrolled. Patients received their last injection of HBIg at the time they initiated tenofovir disoproxil fumarate/emtricitabine (TDF/FTC; Truvada®) and were followed up for 31.1 ± 9.0 [range 15–47] months. Results After 1 year, 3 patients (14%) had detectable HBsAg, one of whom was non-compliant. Two of 3 with recurrence cleared HBsAg by last follow-up on TDF/FTC; the non-compliant patient became HBV DNA-undetectable with re-institution of TDF/FTC. TDF/FTC saved $12,469/year over our standard-of-care, monthly intramuscular HBIg/lamivudine. There was no evidence of a general adverse effect of TDF/FTC on renal function. However, 3 patients developed reversible acute renal failure; on renal biopsy, 1 had possible TDF/FTC-induced acute tubular necrosis. Conclusions Substitution of TDF/FTC for HBIg prevented recurrence of HBV DNA in 100% (20/20) of patients who were compliant with the medication and led to substantial cost savings over HBIg-containing regimens.
Ab initio study of metal gate electrode work function

The work function of metal multilayers and monolayers on bulk metals was studied using the first principle pseudopotential method within the local density approximation in order to find a way to modulate the work function of metal gate electrodes. Various multilayer stacks and bilayer stacks of two systems, Al–Pt and Al–Ni, were examined. It was found that two or three layers of the metal are enough to shift the work function to that of the surface metal. Also, it was found that even a submonolayer could affect the work function of the bulk metal significantly.
Dielectric Studies of Highly Polar Nematic Liquid Crystals and Their Mixtures

Abstract The dielectric properties of the nematic liquid crystal, 4-4′-n-pentylcyanobiphenyl (K15), and three binary mixtures of K15 with 4-[4′-alkylcyclohexyl]cyanophenyl homologs have been studied. The parallel, perpendicular and isotropic dielectric constants are given as a function of temperature. All measurements were made at 1 KHz. Values of e⊥ and e‖, are typically in the range of 7 ± 1 and 17 ± 2, respectively. Temperature ranges from 10°C to TNI + 5°C were explored. The dielectric anisotropy versus T-TNI is also given. 14 > Δe > 7 for pure K15 and all three mixtures when T-TNI < − 1°C. This large dielectric anisotropy is due to the highly polar cyano end group, which has a dipole moment of 4.05 D, and lies along the nematic director for each of these compounds.
Memory overload or expectancy effect? ‘Hysteresis’ revisited∗

The effects of expectancy and variation in task demand on the rate of human information transmission were studied. Subjects performed an eight-choice key-pressing task, attempting to match characters presented singly under both increasing and decreasing demand. The results support previous research indicating that the relationship between the rate of information an individual is able to transmit and task demand depends, at least in part, upon the temporal history of demand. When a relatively high level of demand was imposed, performance failed to recover at the expected rate as demand was reduced. However, this ‘hysteresis’ effect occurred even when a cue was provided to indicate clearly that a reduction in task demand was imminent, suggesting that an overload of short-term memory, rather than an individual's erroneous expectations regarding demand, is primarily responsible for the effect.
Analytical Solutions for the Study of Immersed Unanchored Structures Under Seismic Loading

In nuclear power plants, some structures are not anchored and lay directly on the ground. This is the case for fuel storage racks. As a safety issue, one has to evaluate precisely the behavior of this sliding structure, and in particular, the cumulated sliding displacement during a seismic event in order to prevent any impact with other components. During a seismic event, the unanchored structure can slide, rotate and tilt. The aim of this paper is to present analytical solutions to estimate the sliding amplitudes of different simplified systems which represent a given dynamic behavior. These simplified models are: a sliding mass, a sliding spring-masses system and a complex sliding structure defined by its eigenmodes. Each simplified system corresponds to a different set of assumptions made on the flexibility of the structure. Two analytical solutions are presented in this article: single sliding mass and a sliding spring-masses system. The analytical solutions are obtained considering the different phases of the movement and the continuity between each phase. The results are then compared to the values computed with the commercial Finite Element package ANSYS™. The analytical curves show a good fit of the computational results.Copyright © 2010 by ASME
A qualitative multiresolution model for counterterrorism

This paper describes a prototype model for exploring counterterrorism issues related to the recruiting effectiveness of organizations such as al Qaeda. The prototype demonstrates how a model can be built using qualitative input variables appropriate to representation of social-science knowledge, and how a multiresolution design can allow a user to think and operate at several levels - such as first conducting low-resolution exploratory analysis and then zooming into several layers of detail. The prototype also motivates and introduces a variety of nonlinear mathematical methods for representing how certain influences combine. This has value for, e.g., representing collapse phenomena underlying some theories of victory, and for explanations of historical results. The methodology is believed to be suitable for more extensive system modeling of terrorism and counterterrorism.
Pica Practices of Pregnant Women from Four Wic Clinics in Texas

Abstract LEARNING OUTCOME: To describe pica practices during pregnancy and the association of pica with nutrient intake, pregnancy outcome, and maternal hemoglobin at delivery The objectives of this study were to determine pica practices during pregnancy, and the association of pica with nutrient intake, infant birthweight, gestational age, and maternal hemoglobin at delivery. Mothers (n=281) with infants less than one year old who participated in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) were interviewed regarding pica practices during pregnancy at four clinics in Houston and Prairie View, TX. Their medical records from 31 area hospitals were abstracted. The subjects were 88.6% African American, 6.8% Hispanic, and 4.6% Caucasian. Pica prevalence by substance was as follows: ice 53.7%; ice and freezer frost 14.6%, other substances such as baking soda, baking powder, cornstarch, laundry starch, baby powder, and clay or dirt 8.2%; and no pica 23.5%. Seventy percent of women who reported ice pica had relatives who practiced ice pica. When asked why they ate pica substances, 50% of women just "craved it" or "didn't know". Ninety percent of women who reported ice pica ate it daily. Women who did not report pica had the highest mean educational level, highest prevalence of vitamin usage in all three trimesters, lowest prevalence of smoking, and highest participation in WIC during pregnancy. Using available 24-hour dietary recalls, there were no differences in nutrient intakes between women who practiced ice pica (n=103) and women who denied pica (n=50). There were no significant differences in birthweight or gestational age among infants born to mothers who practiced pica vs. mothers who did not. Women who practiced pica had significantly lower hemoglobin at delivery (p = 0.004) than women who did not report pica. These findings suggest that pica was not associated with pregnancy outcome but was associated with lower maternal hemoglobin at delivery
Prostaglandin E2 stimulates ion transport in prairie dog gallbladder.

The effects of prostaglandins, and specifically prostaglandin E2, on gallbladder ion transport were examined in the prairie dog. Gallbladders were mounted in an Ussing chamber and baseline short-circuit current, potential difference, and tissue resistance were measured. Addition of arachidonic acid (10−4 M, mucosal surface) produced sustained elevations in short-circuit current and potential difference (P<0.05), with mild reductions in resistance. In a second set of tissues, indomethacin exposure (10−6 M) resulted in a significant (P<0.02) decrease in short-circuit current and potential difference, with an increase in resistance. Subsequent addition of prostaglandin E2 (10−7 M, serosal surface) fully reversed these changes and led to a significant increase in short-circuit current and potential difference (P<0.001) with a return of resistance to baseline values. These findings suggest that endogenous prostaglandins mediate gallbladder ion transport.