cssi/SciSciGPT-SciSciNet huggingface dataset:
Corporate Social Responsibility and Goodwill Impairment

ABSTRACT This study examines the relation between corporate social responsibility (CSR) and goodwill impairment. We rely mainly on the stakeholder theory and adopt the Posner (1974) public interest...
Role Transition After Clinical Nurse Specialist Education.

Purpose This study explored the transition of clinical nurse specialists into new roles after completion of their graduate education. Design A quantitative longitudinal survey was used to measure certification, employment, career commitment, and the imposter phenomenon. Methods An online survey was sent to 113 participants from a previous national study that agreed to follow-up. The Student Nurse Anesthetist Experience Questionnaire and Clance Imposter Phenomenon Scale instruments were used. Each case (N = 68) was matched with data from the primary study, and 2 comparison groups were formed based on employment status as a clinical nurse specialist. Results The advanced practice certification rate was 66.7%, and 48.5% were employed as a clinical nurse specialist. The employed group perceived more autonomy, a more positive view of the clinical nurse specialist lifestyle, and upset life plans if not able to practice in the role when compared with the not-employed group. Self-image was significantly different based on employment, but career commitment was not particularly strong regardless of employment status. The prevalence of imposter phenomenon experiences was 74.6% in this sample. Conclusion Recent graduates are struggling with their transition into practice as clinical nurse specialists.
Stained Glass in Three Dimensions

The design for this dress transforms a two-dimensional stained-glass design into an engineered digital textile print that conforms to the contours of the body. In examining antique pieces of stained glass, I have noticed that the shrinkage of wooden frames over time have caused some stained-glass pieces to expand outward to form three-dimensional shapes, an effect that I have used as inspiration for the contours of this design. Rather than referencing historic silhouettes or garment design details, the historic inspiration for this dress was found in Art Nouveau stained glass designs of the early 1900s. The pattern pieces were digitized and printed in half scale. I drew the design by hand onto the pattern pieces, and then used Adobe Photoshop to trace over the hand-drawn design lines and to create half-drop repeat prints to fill the design outlines.
Red flag findings in children with headaches: Prevalence and association with emergency department neuroimaging.

BackgroundClinicians appear to obtain emergent neuroimaging for children with headaches based on the presence of red flag findings. However, little data exists regarding the prevalence of these fin...
Management of the lateral frontal sinus lesion and the supraorbital cell mucocele.

BackgroundMasses that radiographically appear in the lateral aspect of the frontal sinus can be difficult to access and often are approached through external approaches. Supraorbital ethmoid cells ...
Cluster randomized control trial promoting child self-regulation around energy-dense food.

Abstract Children with lower inhibitory control have greater weight gain over time and consume more snack food. Our goal was to test whether a pilot program based on enhancing self-regulation in preschool children could decrease consumption of energy-dense foods. Ninety-two preschool children were randomized to the intervention or control group. The intervention was a three-week, play-based program that focused on enhancing executive function skills and decreasing consumption of energy dense snack foods. Controls met for a similar length of time, but focused on dental hygiene, good sleep habits/routines, and physical activity. Primary outcome included calories consumed during the post-intervention “Eating in the Absence of Hunger” paradigm, controlling for baseline calories consumed. Inhibitory control was assessed using the “Day/Night” and “Less is More” tasks. There were no differences in post-intervention calories consumed between groups (p = 0.42). However, post-hoc analysis revealed a significant interaction between group and weight status (p = 0.04). In the intervention group, overweight/obese and healthy weight children consumed a similar number of calories (118.0 kcals vs. 124.1 kcals respectively, p = 0.64). However, in the control group, overweight/obese children consumed more than normal weight children (155.9 kcals vs. 103.6 kcals respectively; p = 0.01). With regards to inhibitory control, post-hoc analysis revealed a significant interaction between group and age (p = 0.03), with younger children in the intervention group scoring higher than younger children in the control group (0.93 vs 0.78 respectively, p = 0.007). No differences were observed between groups among older children (0.93 vs 0.96, p = 0.42). These types of programs for preschool children may help to temper consumption of excess calories among overweight/obese children. Further development and investigation of pediatric programs that prevent consumption of excess calories are warranted. Trial registration Clinicaltrials.gov: NCT02077387 .
Postpartum hormonal contraception use and incidence of postpartum depression: a systematic review.

Purpose: To evaluate the association between postpartum hormonal contraceptive use and postpartum depression.Materials and methods: We searched the literature through March 2018 on the association ...
Characterization of drought-induced rapid cold-hardening in the Antarctic midge, Belgica antarctica

Survival of the terrestrial midge, Belgica antarctica, on the Antarctic Peninsula is promoted, not only by their adaptations to prolonged exposures to seasonal stresses, but also by their ability to respond to unpredictable changes in their environments. Rapid cold-hardening (RCH) is an extremely swift acclimatory response of insects that occurs within minutes to hours. While the RCH response is most commonly induced by a brief exposure to mildly low temperatures, a similar rapid acclimatory response can also be elicited by exposure to drought. In this study, we characterized this drought-induced RCH in larvae of B. antarctica. Compared to fully hydrated larvae, those desiccated at various relative humidity (R.H.) conditions between 0 and 99% R.H. for 2 h had a significantly greater survival ( ~ 50%) to freezing at − 14 °C. The amount of water loss varied between 4 and 16% depending on R.H. conditions; however, all treatments were equally effective in eliciting the protective response against freezing stress, and its induction was evident within 30 min of desiccation. Lack of substantial changes in body-fluid osmolality or levels of major cryoprotectants suggest that accumulation of these protective solutes is not a primary mechanism of this response. Interestingly, the RCH protection induced by desiccation persisted after larvae were allowed to recover a significant portion of the lost water. Our results indicate that larval midges are highly sensitive to desiccation, capable of swiftly initiating physiological changes in response to a small reduction in their body water content.
Injection risk norms and practices among migrant Puerto Rican people who inject drugs in New York City: The limits of acculturation theory.

Abstract Background Among people who inject drugs (PWID) in New York City (NYC), racial minorities are disproportionately infected with HIV and hepatitis C (HCV). Prior research has shown that PWID who started injecting drugs in Puerto Rico (P.R.) tend to maintain the risky injection behaviors learned there. This study identifies the P.R.-native norms supporting the continued injection risk behavior of migrant Puerto Rican PWID in NYC to inform a culturally appropriate risk-reduction intervention. Methods 40 migrant Puerto Rican PWID were recruited in NYC for a longitudinal qualitative study. The sample was stratified to include 20 migrants with 3-6 years in NYC. Time-location sampling was used to curb possible network bias in recruitment. Over 12 months, migrants completed semi-structured interviews at baseline, monthly follow-ups, and study exit. Analyses were guided by grounded theory. Results Most participants (90%) reported having had chronic HCV, and 22.5% reported being HIV-positive. Syringe- and cooker-/cotton-sharing were widespread in both P.R. and NYC. The ubiquitous practice of cleaning used syringes by “water-rinsing and air-blowing” was guided by a normative belief, learned in P.R., that “water and air kill HIV.” Sterile syringe use was not a priority. HCV was not a concern. P.R.-native abstinence-only narratives discouraged opioid agonist treatment (OAT) enrollment among recent migrants (≤3 years). Experiences with drug dealers, prison-power groups, and injection doctors (“Gancheros”) in P.R. influenced migrants’ injection risk behavior in NYC. Those who were Gancheros in P.R. continued working as Gancheros in NYC. Conclusions Injection risks make migrant Puerto Rican PWID in NYC vulnerable to HIV/HCV. Harm reduction programs should pay closer attention to the rationales behind these injection risks. A risk-reduction intervention that incorporates the Ganchero figure may be a credible way to help migrants reduce injection risk and accept OAT and syringe exchange programs (SEP).
Exercise Testing in Pediatric Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is the most common cardiomyopathy in children, and its hallmark is left ventricular (LV) dilation and systolic dysfunction. Impairment of exercise performance in children with DCM is due to a combination of inadequate tissue O2 delivery resulting from impaired heart rate and stroke volume increase with exercise and abnormalities in distribution or impedance to flow in pulmonary and peripheral circulations and of the skeletal muscle. Formal assessment of exercise performance is useful in identifying limitations and eliciting the mechanism of limitations in children with moderate and severe LV dysfunction and has a potential role in risk stratification of those with severe LV dysfunction.
Do transportation network companies reduce public transit use in the U.S.

Abstract The rise of transportation network companies (TNCs) in recent years has revolutionized urban transportation across the globe. Most noticeably, the increased popularity of TNC services coincides with the declining trend of public transit ridership in the U.S. The impact of TNCs on urban public transit needs to be carefully evaluated in light of the potential implications of any future policy changes in transit funding and planning. Using top 50 U.S. agency-level data from 2007 through 2017, this study examines the effect of TNCs and transit effectiveness on public transit ridership in the U.S. We find that (1) transit effectiveness of both bus and rail transits declined over the study period; (2) TNC availability increased rail transit ridership in 2015; (3) transit effectiveness was highly significant for public transit, and when examining its effect year-by-year, rail transit effectiveness trumped TNC availability; (4) TNCs are neither a complement nor a substitute of bus transit.
Bio-informed Protein Sequence Generation for Multi-class Virus Mutation Prediction

Viral pandemics are emerging as a serious global threat to public health, like the recent outbreak of COVID-19. Viruses, especially those belonging to a large family of +ssRNA viruses, have a high possibility of mutating by inserting, deleting, or substituting one or multiple genome segments. It is of great importance for human health worldwide to predict the possible virus mutations, which can effectively avoid the potential second outbreak. In this work, we develop a GAN-based multi-class protein sequence generative model, named ProteinSeqGAN. Given the viral species, the generator is modeled on RNNs to predict the corresponding antigen epitope sequences synthesized by viral genomes. Additionally, a Graphical Protein Autoencoder (GProAE) built upon VAE is proposed to featurize proteins bioinformatically. GProAE, as a multi-class discriminator, also learns to evaluate the goodness of protein sequences and predict the corresponding viral species. Further experiments show that our ProteinSeqGAN model can generate valid antigen protein sequences from both bioinformatics and statistics perspectives, which can be promising predictions of virus mutations.
Ethically uncharted territory: Providing psychological services to parents in pediatric settings

Pediatric psychologists have much to contribute to growing efforts to mitigate the impact of parent mental and behavioral health problems on children’s health and development. However, providing pa...
Packaged, Fiber-Coupled Waveguide-Enhanced Raman Spectroscopic Sensor

We report a packaged, fiber-bonded waveguide-enhanced Raman spectroscopy (WERS) sensor that uses backscattered collection to filter the background on-chip. We compare waveguide geometries with respect to their filtering performance.
Loss of Individual Mitochondrial Ribonuclease P Complex Proteins Differentially Affects Mitochondrial tRNA Processing In Vivo

Over a thousand nucleus-encoded mitochondrial proteins are imported from the cytoplasm; however, mitochondrial (mt) DNA encodes for a small number of critical proteins and the entire suite of mt:tRNAs responsible for translating these proteins. Mitochondrial RNase P (mtRNase P) is a three-protein complex responsible for cleaving and processing the 5'-end of mt:tRNAs. Mutations in any of the three proteins can cause mitochondrial disease, as well as mutations in mitochondrial DNA. Great strides have been made in understanding the enzymology of mtRNase P; however, how the loss of each protein causes mitochondrial dysfunction and abnormal mt:tRNA processing in vivo has not been examined in detail. Here, we used Drosophila genetics to selectively remove each member of the complex in order to assess their specific contributions to mt:tRNA cleavage. Using this powerful model, we find differential effects on cleavage depending on which complex member is lost and which mt:tRNA is being processed. These data revealed in vivo subtleties of mtRNase P function that could improve understanding of human diseases.
Implementing Regulatory Harmonization at the SEC

Section 913 of the Dodd-Frank Act requires the U.S. Securities and Exchange Commission to conduct a study regarding gaps or deficiencies in the regulation of broker-dealers and investment advisers. These firms often perform similar functions but are regulated differently under an antiquated regulatory scheme. Section 913 sets forth detailed requirements for the SEC’s study. Section 913 also provides the SEC with rulemaking authority to address the standard of care for brokers and advisers, although the SEC’s new authority may be insufficient to address the study’s findings. In light of this inconsistency between the scope of the study and the SEC’s new authority, one might ask how the SEC should proceed. This short essay, prepared as part of a collection of papers on a fiduciary duty for broker-dealers, analyzes the requirement for the study, the authority to adopt new rules, and the gaps between these provisions. The essay suggests that one might best view section 913 as directing the SEC to move along two tracks. The first track is to conduct the required study independent of the rulemaking authority provided in section 913 and unburdened from a background requirement to address the study’s findings. The second track, once the study is completed, is to prepare new rules, even if some of the SEC’s conclusions cannot immediately be addressed through rulemaking and additional legislation is needed. I conclude that the SEC’s rulemaking authority in section 913 ought not shackle the SEC’s willingness to conduct a comprehensive study of broker-dealers and investment advisers.
Single-cell mechanics--An experimental-computational method for quantifying the membrane-cytoskeleton elasticity of cells.

Abstract The membrane–cytoskeleton system plays a major role in cell adhesion, growth, migration, and differentiation. F-actin filaments, cross-linkers, binding proteins that bundle F-actin filaments to form the actin cytoskeleton, and integrins that connect the actin cytoskeleton network to the cell plasma membrane and extracellular matrix are major cytoskeleton constituents. Thus, the cell cytoskeleton is a complex composite that can assume different shapes. Atomic force microscopy (AFM)-based techniques have been used to measure cytoskeleton material properties without much attention to cell shape. A recently developed surface chemical patterning method for long-term single-cell culture was used to seed individual cells on circular patterns. A continuum-based cell model, which uses as input the force–displacement response obtained with a modified AFM setup and relates the membrane–cytoskeleton elastic behavior to the cell geometry, while treating all other subcellular components suspended in the cytoplasmic liquid (gel) as an incompressible fluid, is presented and validated by experimental results. The developed analytical–experimental methodology establishes a framework for quantifying the membrane–cytoskeleton elasticity of live cells. This capability may have immense implications in cell biology, particularly in studies seeking to establish correlations between membrane–cytoskeleton elasticity and cell disease, mortality, differentiation, and migration, and provide insight into cell infiltration through nonwoven fibrous scaffolds. The present method can be further extended to analyze membrane–cytoskeleton viscoelasticity, examine the role of other subcellular components (e.g., nucleus envelope) in cell elasticity, and elucidate the effects of mechanical stimuli on cell differentiation and motility. Statement of Significance This is the first study to decouple the membrane–cytoskeleton elasticity from cell stiffness and introduce an effective approach for measuring the elastic modulus. The novelty of this study is the development of new technology for quantifying the elastic stiffness of the membrane–cytoskeleton system of cells. This capability could have immense implications in cell biology, particularly in establishing correlations between various cell diseases, mortality, and differentiation with membrane–cytoskeleton elasticity, examining through-tissue cell migration, and understanding cell infiltration in porous scaffolds. The present method can be further extended to analyze membrane–cytoskeleton viscous behavior, identify the contribution of other subcellular components (e.g., nucleus envelope) to load sharing, and elucidate mechanotransduction effects due to repetitive compressive loading and unloading on cell differentiation and motility.
Interactions and survival of enteric viruses in soil materials.

There were marked differences in the abilities of eight different soil materials to remove and retain viruses from settled sewage, but for each soil material the behavior of two different viruses, poliovirus type 1 and reovirus type 3, was often similar. Virus adsorption to soil materials was rapid, the majority occurring within 15 min. Clayey materials efficiently adsorbed both viruses from wastewater over a range of pH and total dissolved solids levels. Sands and organic soil materials were comparatively poor adsorbents, but in some cases their ability to adsorb viruses increased at low pH and with the addition of total dissolved solids or divalent cations. Viruses in suspensions of soil material in settled sewage survived for considerable time periods, despite microbial activity. In some cases virus survival was prolonged in suspensions of soil materials compared to soil-free controls. Although sandy and organic soil materials were poor virus adsorbents when suspended in wastewater, they gave ≥95% virus removal from intermittently applied wastewater as unsaturated, 10-cm-deep columns. However, considerable quantities of the retained viruses were washed from the columns by simulated rainfall. Under the same conditions, clayey soil material removed ≥99.9995% of the viruses from applied wastewater, and none were washed from the columns by simulated rainfall.
Displacement chromatography on cyclodextrin-silicas : I. Separation of positional and geometrical isomers in the reversed-phase mode

The retention behaviour of several charged and uncharged solutes on beta-cyclodextrin-silica was studied as a function of the methanol concentration, ionic strength and pH of the eluent in order to develop efficient displacement chromatographic separations for positional and geometric isomers. These retention curves were used to predict the eluent (carrier solvent) compositions that result in solute retentions in excess of k' = 10. The adsorption isotherms of several cationic detergents were determined in these carrier solutions and were found to be convex. The adsorption isotherms of several positional isomers used as test solutes were also determined in these carrier solutions. The adsorption isotherms permitted the development of efficient displacement chromatographic separations for the isomers tested. Column loadings as high as 58 mg were achieved on a regular 4.6 mm I.D. analytical-scale cyclodextrin silica columns.
Policing Disaster: An Analytical Review of the Literature on Policing, Disaster, and Post‐traumatic Stress Disorder

A large body of research findings suggests that law-enforcement officers are confronted with erratic, periodic, and unpredictable high-stress experiences in the line of duty. There is also an increasing amount of research on police as first responders to disasters and their mental health. Recent high-stress events, like the social disorder generated by Hurricanes Sandy and Katrina, the aftermath of the 9/11 attacks, and the violence at Newtown, created a unique matrix for stressors on police officers who may not have had much training to deal with the associated disorder or much social support to draw upon when confronting the residual emotional and mental traumas that they experienced as a result. In this context, we conduct an analytical review of the literature on police stress in instances in which officers have responded to disasters. Moreover we discuss the extant research related to rates of post-traumatic stress disorder, the effects of PTSD and related diagnoses on the personal and professional lives of officers, and the sources of social support available to them in the aftermath of trauma-inducing events. We conclude with a summary of current research and a critique of what is missing in the literature including attention to subclinical PTSD, proper training, the lack of attention to institutional screening for PTSD vulnerability, and the dearth of evaluation research on “what works” in disaster preparedness for police officers.
Separation property for Schrödinger operators in L p -spaces on non-compact manifolds

Let (M, g) be a manifold of bounded geometry with metric g. We consider a Schrodinger-type differential expression L = Δ M + q, where Δ M is the scalar Laplacian on M and q is a non-negative locally integrable function on M. In the terminology of W.N. Everitt and M. Giertz, the differential expression L is said to be separated in L p (M) if for all u ∈ L p (M) such that Lu ∈ L p (M), we have qu ∈ L p (M). We give sufficient conditions for L to be separated in L p (M), where 1 < p < ∞.
Efficacy of MitoTracker Green and CMXrosamine to measure changes in mitochondrial membrane potentials in living cells and tissues.

Background Chloromethyl-X-rosamine (CMXRos) and MitoTracker Green (MTG) have proved to be useful dyes with which to measure mitochondrial function. CMXRos is a lipophilic cationic fluorescent dye that is concentrated inside mitochondria by their negative mitochondrial membrane potential (MMP). MTG fluorescence has been used as a measure of mitochondrial mass independent of MMP. The fluorescence ratio of the two dyes is a relative measure of the MMP independent of mitochondrial mass. Because MTG was recently reported to be sensitive to MMP, we have reevaluated the effects of loss of MMP on MTG and CMXRos fluorescence, using both flow cytometry and laser scanning confocal microscopy (LSCM). Methods Using flow cytometry, the relative fluorescence of CMXRos, R123, and MTG was determined in human lymphoblastoid cell lines (LCLs) with or without carbonyl cyanide p-trifluoromethoxylphenyl-hydrazone (FCCP), used to collapse the MMP. LSCM analysis was also used to evaluate the effect of FCCP on MTG and CMXRos fluorescence of mouse cells and viable lenses in culture. The cytotoxicity of the dyes was determined using flow analysis of endogenous NADH fluorescence. The sensitivity of MTG fluorescence to H2O2 was also evaluated using flow cytometry. Results CMXRos fluorescence was dependent on MMP, whereas MTG fluorescence was not affected by MMP, using either flow or LSCM. Specific staining of mitochondria was seen with both dyes in all cell types tested, without evidence of cytotoxicity, as determined by NADH levels. H2O2 damage slightly increased MTG staining of cells. Conclusions Our results indicate that CMXRos is a nontoxic sensitive indicator of relative changes in MMP, whereas MTG is relatively insensitive to MMP and oxidative stress, using both flow and LSCM analyses, provided optimal staining conditions are used. In addition, these dyes can be useful for the study of mitochondrial morphology and function in whole tissues, using LSCM. © 2004 Wiley-Liss, Inc.
YB-1 Binds to the MMP-13 Promoter sequence and Represses MMP-13 Transactivation via the AP-1 site

Matrix metalloproteinases (MMPs) are key enzymes that implement degradation of the extracellular matrix during cellular invasion in development, tissue remodeling, and pathogenic disease states. MMP-13 has pivotal roles in the pathogenesis of invasive cancers and arthritis. Here we report the identification of Y-box binding protein-1 (YB-1) as a new repressor of MMP-13 transactivation. YB-1 binds in vitro in DNA affinity chromatography to the activator protein-1 (AP-1) DNA sequence within the MMP-13 promoter. Chromatin immunoprecipitation assays reveal that YB-1 binds in living cells to the MMP-13 gene promoter to a region of the MMP-13 promoter containing the AP-1 site. YB-1 represses tumor promoter-induced MMP-13 promoter transactivation at the AP-1 site. This is the first report demonstrating YB-1 binding in vitro and in living cells to a mammalian AP-1 target gene, and the first report of YB-1 regulation of the MMP-13 promoter.
Analysis of Photonuclear Cross Sections

The problem of obtaining a photonuclear cross section from a yield curve measured with a bremsstrahlung beam is discussed. This paper constitutes part of a larger report on the same subject containing numbers enabling cross-section analysis in the energy range 2 Mev to 1 Bev.
Binding of ciprofloxacin by humic substances: A molecular dynamics study

A comprehensive assessment of the potential impacts of antimicrobials released into the environment requires an understanding of their sequestration by natural particles. Of particular interest are the strong interactions of antimicrobials with natural organic matter (NOM), which are believed to reduce their bioavailability, retard their abiotic and biotic degradation, and facilitate their persistence in soils and aquatic sediments. Molecular dynamics (MD) relaxation studies of a widely used fluoroquinolone antibiotic, ciprofloxacin (Cipro), interacting with a model humic substance (HS) in a hydrated environment, were performed to elucidate the mechanisms of these interactions. Specifically, a zwitterionic Cipro molecule, the predominant species at circumneutral pH, was reacted either with protonated HS or deprotonated HS bearing Ca, Mg, or Fe(II) cations. The HS underwent conformational changes through rearrangements of its hydrophobic and hydrophilic regions and disruption of its intramolecular H-bonds to facilitate favorable intermolecular H-bonding interactions with Cipro. Complexation of the metal cations with HS carboxylates appeared to impede binding of the positively charged amino group of Cipro with these negatively charged HS complexation sites. On the other hand, an outer-sphere complex between Cipro and the HS-bound cation led to ternary Cipro-metal-HS complexes in the case of Mg-HS and Fe(II)-HS, but no such bridging interaction occurred with Ca-HS. The results suggested that the ionic potential (valence/ionic radius) of the divalent cation may be a determining factor in the formation of the ternary complex, with high ionic potential favoring the bridging interaction. Environ. Toxicol. Chem. 2010;29:90-98. (c) 2009 SETAC.
Patterns in eigenvalues: the 70th Josiah Willard Gibbs lecture

Typical large unitary matrices show remarkable patterns in their eigenvalue distribution. These same patterns appear in telephone encryption, the zeros of Riemann’s zeta function, a variety of physics problems, and in the study of Toeplitz operators. This paper surveys these applications and what is currently known about the patterns.
Assessment of online participation through social network measures: A HLM approach

In this research, we bring attention to one of the largest electrical and computer engineering (ECE) online discussion forums AllAboutCircuits.com. There are close to two hundred thousand learners contributing more than a million messages to this forum for over more than a decade. The massive archives of educational data raise an important question for engineering educators: How do we assess online participation? In this work-in-progress, we propose a multilevel approach to assess online participation based on social network measures and Hierarchical Linear Modeling (HLM) techniques. Specifically, we consider the employment of HLM to model the association between online participation and measures of social capital. Predictors of social capital are established, at both the individual and group levels, to examine the association between these predictors and learners' participation frequencies. We discuss our choice of HLM as a modeling approach over ordinary least squares (OLS) regression methods. We then describe how data is collected from the site of study, AllAboutCircuits.com, and how the modeling approach is conceptualized and used for assessment purposes. The importance of this work lies not only on sheer participation figures - it derives from the argument that online discussion fosters productive collaborative learning and individual reflection.
Aspects of isochronism in Pb isotope systematics—application to planetary evolution

Abstract Some interrelated aspects of lead isotope systematics are exposed and their bearing on the problem of planetary evolution is discussed. In particular, three concepts are stressed: 1. (1) Point of isometry (PI): Pb-Pb isochrons of rocks of different ages which remain undisturbed since they were derived from the same homogeneous source intersect with each other at a single point (point of isometry) which describes the present day Pb composition of their common source. For a continually differentiating planet, where the composition of a source changes with time, a ‘domain’ rather than a ‘point’ of isometry may exist. However, because of geometric effects an illusionary point of isometry yielding a lower limit to the age of ‘the’ source—may still be obtained. 2. (2) Dispersive isochronism: Isochronous, cognate, closed systems (e.g. an undisturbed rock and its minerals) that contain variable Th/U do not define an isochron on 208,206,204 pb correlation diagram. The dispersion of the isotopic data of such systems from a line is proportional to the variability in Th/U. It is suggested that the individual dispersion trajectories may be experimentally determined. In theory these trajectories must all meet in a point of convergence (PC) which represents a true end point common to the systems. PC yields the composition of initial Pb which can be used to calculate the age of the source irrespective of one's success or failure in directly determining initial Pb from U and Th-poor mineral phases. Some experimental evidence to the feasibility of the method is provided. 3. (3) Congruency of galenas: It is possible to construct a hypothetical ‘source profile’ which shows a spectrum of Pb compositions for sources of different ages which could have each produced a given galena at hand. Galenas of different ages, derived from the same homogeneous source, have different source profiles which nevertheless intersect each other at a single point corresponding to their parental source. Establishment of a point of intersection for a number of galenas is not an unequivocal proof for a homogeneous source, however, because mild heterogeneities could be smoothed out by geometric effects. Old conformable galenas yield an intersection corresponding to a common source which is 4.54 Byr old.
Validation of the Revised Individual Placement and Support Fidelity Scale (IPS-25).

Objective:The individual placement and support (IPS) model of supported employment for people with severe mental illness is an evidence-based practice. The 15-item IPS Fidelity Scale (IPS-15) was developed to measure program fidelity and has been shown to have good psychometric properties, including predictive validity. On the basis of field experience and research updates, the authors developed an expanded and revised version of this scale, the IPS-25, also known as the Supported Employment Fidelity Scale. This study evaluated the psychometric properties of the IPS-25. Methods:In addition to data on the local unemployment rate and program longevity, the authors collected IPS-25 ratings and employment data for 79 sites in eight states participating in a learning collaborative devoted to implementing the IPS model. Descriptive data for items and the total scale and predictive validity were examined. Results:Internal consistency reliability for the IPS-25 was .88. Predictive validity, measured as the correl...
Cyberspace, the New Frontier

The article examines the impact of technology on career services practitioners and administrators, our customers, the educational system, and the society in general. It attempts to identify some of the different paths along which technology is moving, and how these different paths will impact our profession, delivery systems, and the need for training on one hand, and on the other, how we communicate, live, and survive in our ever changing society. Technological advances may not follow what we think should happen, nor can we undo what has already happened, so our focus will be on the future, or what could happen. The authors present a description of some of the uses of technology in career services, like virtual fairs, job posting programs, chat rooms, resume programs, work study employment, and basic career service web sites. They also address concerns regarding who is attempting to provide services to our students, what credentials and/or training those individuals possess, and the purpose of their efforts.
The thymus: Its influence on recognition of “self major histocompatibility antigens” by T cells and consequences for reconstitution of immunodeficiency

It has become clear that severe combined immunodeficiency (SCID) is a heterogeneous group of congential disorders and, similarly, that thymus hypoplasia or deficiency may have various aetiologies [1–4]. Thus, immunodeficiency can result if the thymus either fails to produce thymic hormone or fails to provide adequate epithelial cell-cell contact mechanisms to induce T cell differentiation. Stem cells may also be defective and cause immunodeficiency either because they are blocked in their normal differentiation programs or because they fail to enter the thymus or circulate properly through [5, 6]. Attempts at reconstituting immunodeficient patients by administering fetal thymus or stem cells have met with variable success. Immunocompetence may be restored to the degree that such patients responded to stimulation with PHA or rejected foreign skin grafts; unfortunately, in some cases they showed no increase in antibody production nor any lessening of their high susceptibility to infectious disease [1, 7–12]. In most of the clinical attempts at reconstitution, bone marrow transplants were HLA matched with the recipient, but not thymic or fetal liver cells [1]. The reasoning was that these fetal organs and cells were taken before immunocompetency was reached; therefore, a graft-versus-host disease was not possible [1–4]. Our hypothesis and experimental model in mice may offer an explanation for the variable therapeutic successes with fetal grafts and may reveal a basis for establishing improved rules for cellular engineering in reconstituting immunodeficient patients.
An apparatus to measure the structure of the pion

Abstract We discuss the design and performance of a large-acceptance double-magnet spectrometer used in Fermilab Experiment 615. The apparatus was used to measure the properties of high-invariant-mass muon pairs produced in collisions of a pion beam with a tungsten target in order to infer the distribution of quarks within the pion and to study the production mechanism in detail. The emphasis was on interactions in which a single quark, and subsequently the muon pair, carried a large fraction of the pion's momentum. A hardware trigger processor enabled the detector to extract the relatively weak signal while operating in a high-rate environment.
Integration of pre-aligned liquid metal electrodes for neural stimulation within a user-friendly microfluidic platform

Electrical stimulation of nervous tissue is used clinically for the treatment of multiple neurological disorders and experimentally for basic research. With the increase of optical probes to record neuronal activity, simple and user-friendly methods are desired to stimulate neurons and their subcellular compartments for biological experimentation. Here we describe the novel integration of liquid metal electrodes with microfluidic culture platforms to accomplish this goal. We integrated electrode and cell channels into a single poly(dimethylsiloxane) (PDMS) chip, eliminating entirely the need to align electrodes with microchannels. We designed the electrode channels such that the metal can be injected by hand and when the device is non-covalently bound to glass. We demonstrated the biocompatibility of the electrodes for long-term cultures (12 days) using hippocampal neurons. We demonstrated the use of these electrodes to depolarize neurons and recorded neuronal activity using the calcium indicator dye, Fluo-4. We established optimal stimulation parameters that induce neuronal spiking without inducing damage. We showed that the liquid metal electrode evoked larger calcium responses in somata than bath electrodes using the same stimulus parameters. Lastly we demonstrated the use of these liquid metal electrodes to target and depolarize axons. In summary, the integration of liquid metal electrodes with neuronal culture platforms provides a user-friendly and targeted method to stimulate neurons and their subcellular compartments, thus providing a novel tool for future biological investigations.
Plugging by hydrodynamic bridging during flow of stable colloidal particles within cylindrical pores

This paper describes the flow-induced retention of charge stabilized colloidal particles during flow through cylindrical pores. Current models describing the low-Reynolds-number flow behaviour of particulate suspensions through porous media do not predict retention of stable colloidal particles if the particles are smaller in size than the pores, and the particles and the pores have like surface charges. Retention is not expected under these conditions because the small particle size relative to the pore constriction size precludes straining (physical capture of particles larger than the pore constriction) while particle-pore surface electrostatic repulsion prevents deposition. However, the experiments show that substantial particle retention can occur under these conditions. The mechanism causing particle retention under these conditions, hydrodynamic bridging, is flow-induced. In this mechanism, hydrodynamic forces acting on particles arriving at a pore entrance do not allow their simultaneous passage through the pore, resulting in the formation of a particle bridge across the pore constriction. This paper reports experiments elucidating the effects of velocity, particle concentration, and the ratio of pore size to particle size on retention by hydrodynamic bridging. For flow through cylindrical pores, the effect of velocity on retention by bridging is opposite to that of retention by deposition. Furthermore, observations indicate the existence of a critical flow velocity necessary for particle bridging to occur. This critical velocity is a measure of the net colloidal interparticle and particle-porous medium repulsion that must be overcome by the hydrodynamic forces for bridging to occur. Approximate theoretical calculations of the trajectories of two particles approaching an isolated cylindrical pore are also presented. These calculations show that bridging is indeed possible in the Stokes flow regime for the experimental conditions considered.
Brief history of surgical timing: surgery for ruptured intracranial aneurysms

The neurosurgical profession has taken a circuitous route to attain its current knowledge about timing for aneurysm surgery. While addressing the timing issue, neurosurgeons were beset by many pressures simultaneously. They were forced to justify not only optimal surgical techniques but the need for surgery at all in the treatment of ruptured aneurysms. The beliefs of surgeons with strong personalities, in addition to intuitive guesses, often served to guide surgery in the absence of scientific evidence. That any progress could be made against a background of desperately ill patients and frustrating early results is remarkable. The author briefly outlines the controversies and misdirection that accompanied this progress toward understanding surgical timing in the treatment of ruptured aneurysms.
Reaction of titanium dioxide with sodium cyanide at 1000° C

La reaction du titre est plutot complexe. On a pu identifier: TiN, Na 2 Ti 6 O 13 , Na 8 Ti 5 O 14 comme produits principaux et Na 2 Ti 3 O 7 , C, Na 2 C 2 , CO 2 comme produits secondaires
Detection of an estrogen receptor in two nematode species and inhibition of binding and development by environmental chemicals.

The presence of estrogen receptors or binding proteins was demonstrated in the free-living nematode species Panagrellus redivivus and Caenorhabditis elegans by radioimmunoassay. Twenty-five nanomolar concentrations of toxaphene, dieldrin, and dieldrin plus nonylphenol significantly inhibited estrogen binding to the receptor in P. redivivus. Binding was inhibited but not significantly by 25 nM nonylphenol, toxaphene plus dieldrin, or toxaphene plus nonylphenol. The current research supports the hypothesis that dieldrin, nonylphenol, and toxaphene may mimic estrogen, altering the normal pathways of estrogen metabolism. Based on observations of secondary sex structures, estrogenic chemicals had no effect on sex ratios or growth in Panagrellus redivivus, but caused a reduction of fecundity in this nematode.
Third-party interventions in dyadic play between littermates of domestic dogs, Canis lupus familiaris

Interventions occur when animals interfere in competitive interactions between two or more individuals. Interveners can alter the nature of the ongoing interaction by targeting one party (attacking, biting) and supporting the other. Three theories have been proposed to account for intervention behaviour: kin selection, reciprocity and direct benefits. The kin selection hypothesis predicts that interveners will selectively support relatives over nonrelatives; the reciprocity hypothesis predicts that when intervener ‘A’ supports individual ‘B’, later ‘B’ will intervene and support ‘A’; and the direct benefits hypothesis predicts that target/support patterns should serve the immediate interests of the intervener. We tested the reciprocity and direct benefits hypotheses by exploring third-party interventions in play fighting among littermates of domestic dogs. Interveners in dyadic play did not preferentially target or support preferred playmates of the intervener. Interveners targeted the dog in the losing role at the time of the intervention, and they did not show reciprocity in support. Taken together, these last two findings suggest that littermates benefit directly and use interventions opportunistically to practise offence behaviours directed at littermates already behaving subordinately. Opportunities to practise targeting in a playful setting may help structure dominance relationships among littermates. Additionally, the tendency for puppies to do what the other is doing (target the dog in the losing role) may pave the way for synchronizing cooperative behaviours during group hunting and territorial defence. The types of behaviours used to intervene changed over development, but the outcome following an intervention remained stable.
Inhibitors of sterol synthesis. Effect of dietary 5α-cholest-8(14)-EN-3β-OL-15-one on acat activity of jejunal microsomes of the rat

Dietary administration (0.1% in a chow diet for 8 days) of 5 alpha-cholest-8(14)-en-3 beta-ol-15-one, a potent inhibitor of sterol biosynthesis with marked hypocholesterolemic action, to rats caused a 77% reduction in the levels of acyl co-enzyme A:cholesterol acyl transferase activity of jejunal microsomes relative to those observed in pair-fed control animals. No differences were observed in mean levels of cholesterol concentration in jejunal microsomes of experimental and pair-fed control animals.
Comparison of Social Desirability Effects on the Epps in Relation to Ratings of Compatibility or Incompatibility of the Needs

Summary.,The murually facilitating or inhibiting property of the needs of the EPPS, as measured by compntibility-incompatibility (CI) ratings, is an important determinant of the need-profiles; for the nine compatible needs it is a more important determinant than is the SD property of the needs. A tendency toward different functioning of the CI and SD ratings is noticeable on the compatible needs and marked on the incompatible needs. For all Ss, regardless of group, and for each set of needs, the scores are a direct linear expression of SD and a simple curvilinear expression of Ci. SD mostly determines profile differences between men an; women, while CI mostly determines profile differences between college studenn and adults. The simple use of a test is often involved with the complex aspects of other measurement procedures. This smdy is like that, being an evaluation and comparison of two measurement scales which are really properties of the 15 needs of the EPPS. We wanted to evaluate and compare the social desirability content of the needs with the degree to which the needs are generally compatible or incompatible with each other. Essentially, we wanted to know if the compatibilityincompatibility (CI) of the needs is evidenced, and can be used, independently of the social desirability (SD) property of the needs. The leading alternative would be rhat the compatibility-incompatibility property is subordinate to the social desirability value of the needs. We knew before doing this study that the SD and CI properties of the needs are independent in the tesr with a nonsignificant correlation of .17 for all 15 needs. when the 15 needs are divided into 9 compatible needs and 6 incornpatible needs (described below), the correlations are still not significant, being .29 for the 9 compatible needs and .33 for the 6 incompatible needs. It had previously been demonstrated thac the CI properties of the EPPS are considerable
The biology of human parenting: insights from nonhuman primates

Primate and human parenting have often been viewed as completely emancipated from neuroendocrine influences and primarily dependent on experience, social and cognitive processes. A review of recent findings of primate research on the neurobiological regulation of parental responsiveness, the causes of variability in parenting styles, and the determinants of infant abuse suggests that primate parenting is more sensitive to neuroendocrine mechanisms than previously thought. The findings of primate research can have important implications for human research and encourage the investigation of biological influences on human parenting.