cssi/SciSciGPT-SciSciNet huggingface dataset:
Active regions losing their moorings by subsurface reconnection

The properties of emerging active regions suggest that they originate from deep flux bundles with a field strength well above the equipartition value, so that they can resist strong deformation by convection as they surface. Yet upon flux emergence, the field appears in a multitude of bundles with a field strength near to equipartition with the pressure component that is associated with the convective motions. During the subsequent decay of active regions, the flux disperses in a random walk that seems to be caused uniquely by the flows in the near-surface convection. We propose that this apparently untethered random walk is the consequence of subsurface reconnection, which leads to the formation of flexible weak-field connections between the strong, buoyant top segments, cut loose from the deep source region. The frequent reconnection between flux tubes underneath each of the polarities in the active region acts to maintain an approximately vertical organization of the subsurface field. We concur with earlier studies that the distribution of the field can be described by the horizontal dispersal of a scalar at least in these layers near the surface, because in addition to this combing of the field, mixing-length models suggest that the horizontal diffusion coefficient is almost constant down to a depth of some 10 000 km. Our model predicts that the sub-surface reconnection between fields of opposite polarity causes the surface field to be disconnected from the deep source region on a time scale that is in fair agreement with the observed lifetimes of active regions of a range of sizes. We explore whether branching of flux bundles into ever smaller bundles between the bottom of the convective envelope and the photosphere allows the limited bending of flux tubes by convection that is required to induce reconnection.
Nesfatin‐1: a novel inhibitory regulator of food intake and body weight

The protein nucleobindin 2 (NUCB2) or NEFA (DNA binding/EF-hand/acidic amino acid rich region) was identified over a decade ago and implicated in intracellular processes. New developments came with the report that post-translational processing of hypothalamic NUCB2 may result in nesfatin-1, nesfatin-2 and nesfatin-3 and convergent studies showing that nesfatin-1 and full length NUCB2 injected in the brain potently inhibit the dark phase food intake in rodents including leptin receptor deficient Zucker rats. Nesfatin-1 also reduces body weight gain, suggesting a role as a new anorexigenic factor and modulator of energy balance. In light of the obesity epidemic and its associated diseases, underlying new mechanisms regulating food intake may be promising targets in the drug treatment of obese patients particularly as the vast majority of them display reduced leptin sensitivity or leptin resistance while nesfatin-1's mechanism of action is leptin independent. Although much progress on the localization of NUCB2/nesfatin-1 in the brain and periphery as well as on the understanding of nesfatin-1's anorexic effect have been achieved during the past three years, several important mechanisms have yet to be unraveled such as the identification of the nesfatin-1 receptor and the regulation of NUCB2 processing and nesfatin-1 release.
The search for failed supernovae with the Large Binocular Telescope: first candidates

We are monitoring 27 galaxies within 10 Mpc using the Large Binocular Telescope to search for failed supernovae (SNe), massive stars that collapse to form a black hole without a SN explosion. We present the results from the first 4 years of survey data, during which these galaxies were observed to produce 3 successful core-collapse SNe. We search for stars that have "vanished" over the course of our survey, by examining all stars showing a decrease in luminosity of $\Delta \nu L_{\nu} \ge 10^4L_{\odot}$ from the first to the last observation. We also search for the low luminosity, long duration transients predicted by \citet{lovegrove2013} for failed explosions of red supergiants. After analyzing the first 4 years of data in this first direct search for failed SNe, we are left with one candidate requiring further study. This candidate has an estimated mass of 18-25$M_{\odot}$, a mass range likely associated with failed SNe and, if real, implies that failed SN represent a median fraction of $f \simeq 0.30$ of core-collapses, with symmetric 90% confidence limits of $0.07 \le f \le 0.62$. If follow up data eliminate this candidate, we find an upper limit on the fraction of core collapses leading to a failed SN of $f<0.40$ at 90% confidence. As the duration of the survey continues to increase, it will begin to constrain the $f \simeq$ 10-30% failure rates needed to explain the deficit of massive SN progenitors and the observed black hole mass function.
Ethical Issues in Research and Scholarship

As graduate students, you will encounter a number of ethical issues in research and scholarship. In this chapter we draw your attention to many of these issues and provide a framework for discussion and decision making. However, the choices will not always be clear-cut. The most important aspect of making good decisions is to have good information and obtain advice from trusted faculty. The major topics to be presented include misconduct in science, working with faculty and other graduate students, using humans as subjects in research, and using animal subjects.
Product review of alternative computer workstations as possible workplace accommodations for people with chronic low back pain

Problems with chronic low back pain (LBP) impact the lives of many working age adults. The condition can leave people frustrated when their desire to work conflicts with their need to relieve the chronic discomfort. Because physical labor can aggravate the condition, persons with LBP may seek a more sedentary type of employment, such as video display terminal (VDT) operator. Unfortunately, typical VDT workstations require the operator to sit upright, which may increase the discomfort of an operator with LBP. Alternative computer workstations have been designed to allow the VDT operator to access the computer from a significantly reclined or supine posture. These postures have been shown to relieve some forms of LBP. This paper describes a comparison between twenty-four alternative computer workstations as potential workplace accommodations for people with LBP. Just under half (46%) of the systems reviewed, are designed for use only with a laptop computer, and will not support full-size monitor and keyboard. Only 33% allow access to full-size computer components from both a reclined and a supine posture. Complexity of component adjustment and awkward positioning for ingress and egress make these systems less than optimal for accommodating people with LBP in a typical VDT workplace environment.
Skyrmion creation and annihilation by spin waves

Single skyrmion creation and annihilation by spin waves in a crossbar geometry are theoretically analyzed. A critical spin-wave frequency is required both for the creation and the annihilation of a skyrmion. The minimum frequencies for creation and annihilation are similar, but the optimum frequency for creation is below the critical frequency for skyrmion annihilation. If a skyrmion already exists in the cross bar region, a spin wave below the critical frequency causes the skyrmion to circulate within the central region. A heat assisted creation process reduces the spin-wave frequency and amplitude required for creating a skyrmion. The effective field resulting from the Dzyaloshinskii-Moriya interaction and the emergent field of the skyrmion acting on the spin wave drive the creation and annihilation processes.
Body Size Regression Formulae, Proximate Composition and Energy Density of Eastern Bering Sea Mesopelagic Fish and Squid.

The ecological significance of fish and squid of the mesopelagic zone (200 m–1000 m) is evident by their pervasiveness in the diets of a broad spectrum of upper pelagic predators including other fishes and squids, seabirds and marine mammals. As diel vertical migrators, mesopelagic micronekton are recognized as an important trophic link between the deep scattering layer and upper surface waters, yet fundamental aspects of the life history and energetic contribution to the food web for most are undescribed. Here, we present newly derived regression equations for 32 species of mesopelagic fish and squid based on the relationship between body size and the size of hard parts typically used to identify prey species in predator diet studies. We describe the proximate composition and energy density of 31 species collected in the eastern Bering Sea during May 1999 and 2000. Energy values are categorized by body size as a proxy for relative age and can be cross-referenced with the derived regression equations. Data are tabularized to facilitate direct application to predator diet studies and food web models.
Experimental investigation of the transverse mechanical properties of a single Kevlar® KM2 fiber

Abstract A new experimental setup is developed to investigate the transverse mechanical properties of Kevlar ® KM2 fibers, which has been widely used in ballistic impact applications. Experimental results for large deformation reveal that the Kevlar ® KM2 fibers possess nonlinear, pseudo-elastic transverse mechanical properties. A phenomenon similar to the Mullins effect (stress softening) in rubbers exists for the Kevlar ® KM2 fibers. Large transverse deformation does not significantly reduce the longitudinal tensile load-bearing capacity of the fibers. In addition, longitudinal tensile loads stiffen the fibers' transverse nominal stress–strain behaviors at large transverse deformation. Loading rates have insignificant effects on their transverse mechanical properties even in the finite deformation range. An analytical relationship between transverse compressive force and displacement is derived at infinitesimal strain level. This relation is used to estimate the transverse elastic modulus of the Kevlar ® KM2 fibers, which is 1.34 ± 0.35 GPa.
Multiple dental follicles with odontogenic fibroma-like changes (WHO type)

A 15-year-old boy, in the case presented in this article, had 13 unerupted teeth, each associated with hyperplastic pericoronal tissue that showed histologic features suggestive of the WHO type of odontogenic fibroma. The etiology, clinical features, radiographic findings, and histopathology of the odontogenic fibroma are reviewed. It is suggested that the unusual pericoronal findings represent a hamartomatous change.
U.S. public transit earnings, employment and privatization

Abstract This paper uses individual worker and municipal information to examine privatization's influence on public transit workers' earnings and employment. OLS findings on labor earnings reveal that privatization is associated with an erosion of the public transit union premium. These labor earning findings do not change when correcting for privatization heterogeneity, as unobserved worker characteristics do not differ with differing levels of municipal privatization of public transit services. The employment findings reveal that union public transit workers are more likely to be employed in the public sector and this union–nonunion employment probability differential, declines with increasing levels of privatization. This employment result is interpreted as suggesting that labor cost savings from privatization can be derived from the enhanced employment of relatively low wage nonunion workers in the public sector of public transit services.
Development of unavailability expressions for one- and two-component systems with periodic testing and common-cause failures

Analytical expressions have been derived for the calculation of one- and two-component system unavailability under test conditions for unrepaired and undetectable failures. Time-dependent unavailability models have been combined with Markov models, including common-cause failures using the beta-factor formulation of Fleming. The resulting expressions represent a new approach to calculating system unavailability that can be compared to the more commonly used approximate expressions that include random failures only. Results of the comparison show that, for identical components arranged in parallel, the approximate expressions can result in gross underestimation of system unavailability of up to several orders of magnitude, depending upon the relative magnitude of the component beta-factor. However, for systems of identical components arranged in series, the inclusion of common-cause failures actually reduces the calculated system unavailability. Recommendations are made for the implementation of these expressions in large-scale nuclear power plant probabilistic risk assessments (PRAs).
On the Semi-geostrophic System in Physical Space with General Initial Data

In order to accommodate general initial data, an appropriately relaxed notion of renormalized Lagrangian solutions for the Semi-Geostrophic system in physical space is introduced. This is shown to be consistent with previous notions, generalizing them. A weak stability result is obtained first, followed by a general existence result whose proof employs said stability and approximating solutions with regular initial data. The renormalization property ensures the return from physical to dual space; as consequences we get conservation of Hamiltonian energy and some weak time-regularity of solutions.
Physical and psychological attributes of fatigue in female heart transplant recipients.

Abstract Background The attributes of fatigue after orthotopic heart transplantation (OHT) are poorly understood. We conducted this study to assess the prevalence, severity and correlates of fatigue among female OHT survivors. Methods Fifty women (age 54.7 ± 13.0 years) from a single heart transplant center, who underwent OHT 5.1 ± 4.4 (mean ± SD) years earlier, completed a battery of questionnaires including the Profile of Mood States–fatigue sub-scale to assess levels of fatigue, the Beck Depression Inventory to measure depression, and the Short Form-36 to measure functional status and mental health. Demographic and clinical data were obtained from self-reports and medical chart reviews. Results Women reported mean scores of 15.7 ± 6.8 (range 3 to 27), 13.2 ± 8.2 (range 0 to 38), 37.2 ± 10.8 (range 22 to 62) and 41.5 ± 11.2 (range 17 to 60) for fatigue, depression, functional status and mental health, respectively. Univariate analyses revealed that sociodemographic and clinical variables (e.g., age, employment status, anemia, renal insufficiency) were significantly related to fatigue ( p p R 2 = 0.23, p R 2 = 0.39, p R 2 = 0.60, p R 2 = 0.69, p p Conclusions Fatigue is common in women after OHT and is associated with both physiologic and psychologic factors. Clinicians should evaluate all female recipients for symptoms of fatigue, especially those with anemia, renal insufficiency, poor functional status and depression. Other potential mediators of fatigue, such as the denervated donor heart and type of immunosuppressive regimen, may also play a role and require further study.
Ethanol-mediated regulation of transcription factors in immunocompetent cells

The immunomodulatory effects of acute and chronic alcohol use are characterized by impaired antigen-specific immune activation and by increased susceptibility to infections due to alterations in innate immune responses and inflammatory mediator production. The central feature of cellular responses to inflammatory and stress signals is the activation of the nuclear regulatory kappa B/Rel family of transcriptional factors via various surface receptor systems in immunocompetent cells. Activation of NF-kappa B, however, is regulated at multiple levels including I-kappa B degradation, nuclear translocation, and by interaction of NF-kappa B/Rel with other transcription factors. Data from our and other laboratories demonstrate that acute alcohol treatment inhibits activation and nuclear binding of the p65/p50 NF-kappa B functional heterodimer in human monocytes, a mechanism likely contributing to inhibition of pro-inflammatory cytokine production. Here we show that acute alcohol-mediated inhibition of NF-kappa B activation in various monocytic cells including human monocytes and murine macrophages. Inhibition of NF-kappa B activation by alcohol in monocytic cells was independent of I-kappa B alpha degradation. These acute-alcohol-induced changes in monocytic cells were different compared to T lymphocytes, both in Jurkat CD4 cells and peripheral human T cells, acute alcohol had a biphasic effect on TNF-alpha-induced NF-kappa B activation via an I-kappa B alpha-dependent mechanism. Inhibition of NF-kappa B activation by acute alcohol in LPS-activated human monocytes was associated with an increase in nuclear glucocorticoid receptor (GR) levels and reduced GR binding to the glucocorticoid response element (GRE). Together these findings support the hypothesis that in the presence of alcohol, nuclear interaction of NF-kappa B (p65) with glucocorticoid receptor and/or other transcription factors may contribute to the reduced NF-kappa B activation. In contrast to the inhibitory effects of acute alcohol on NF-kappa B activation in monocytic cells, chronic alcohol use and alcoholic hepatitis result in an augmentation of NF-kappa B activation and pro-inflammatory cytokine induction. These results suggest that the complex interactions of the NF-kappa B/Rel and related transcription factors including GR and heat-shock responses determine the level of activation of the immunocompetent cells in response to the challenge of acute and chronic alcohol use at the single cell level.
Near-field sensor using photonic crystal slabs

We introduce a novel displacement sensing mechanism using photonic crystal slabs coupled in the near-field regime. The characteristics are completely different from conventional Fabry-Perot sensors, and high sensitivity can be obtained without using high-reflectivity mirrors.
Work rules and manufacturing cells: a case study

Abstract The advent of a number of new manufacturing processes available to factories in the U.S.A. heralds the beginning of a return to competitiveness for many U.S. industries. The key to the effectiveness of these new systems is their flexibility; however, in order for them to be implemented, a change is required in the traditional, restrictive work rules that govern the organization of most factories. This paper reviews the changes that are occurring in both manufacturing systems and work rules and details the efforts of Ingersoll-Rand who established a manufacturing cell in a previously very traditional and restrictive plant. This case study was based on interviews with Ingersoll-Rand managers who were responsible for implementing the change to manufacturing cells and an analysis of the reports they submitted to management to document the results of the change.
A Study on the Application of Work Factor Approach to Composite Laminates

Static fracture tests using the cracked lap shear (CLS) specimens made of thermoplastic composite APC-2 were conducted to verify if the elastic work factor devel oped previously is a valid parameter to calculate energy release rate from a single speci men. Also, the elastic work factor was derived theoretically based on a beam analysis. The experimentally determined elastic work factor, (ηel)exp was compared with those calculated from a beam analysis and a finite element analysis. The results showed that the elastic work factors determined from these three ways are comparable to each other. In ad dition, the elastic work factor was applied to determine a critical energy release rate, and it was found that the elastic work factor approach can be used to determine energy release rate from a single specimen.
276 POSSIBLE MECHANISM FOR NON-REJECTION OF THE DEVELOP-2/6 ING MAMMALIAN EMBRYO: THE ROLES OF UTEROGLOBULIN AND TRANSGLUTAMINASE

The suppression of embryonic immunogenicity by the interaction of rabbit blastocysts with uteroglobin (UG) (a pregnancy specific protein) and transglutaminase (TG) (Factor XIIIa) has been investigated in vitro. When incubated with maternal lymphocytes, washed, mitomycin-C inactivated blastomeres stimulated lymphocyte 3H-thymidine incorporation (1.23 × 105 cpm/2 × 106 lymphocytes), suggesting recognition of embryonic antigens. When these blastomeres are pretreated with pregnant uterine flushings (PUF), 3H-thymidine incorporation was dramatically reduced (1.0 × 104 cpm/2 × 106 lymphocytes). Pretreatment of blastomeres with UG alone, isolated to homogeneity from PUF, or in combination with TG caused significant dose dependent suppression of thymidine incorporation by the lymphocytes. Suppression to <100 cpm/2 × 106 cells was achieved by 250 ug/ml of UG alone; with added TG (3 u/ml) only 1.0 ug/ml of UG caused total suppression. Suppression was blocked by incubation of UG with its antiserum, or with TG plus anti-TG, prior to blastomere pretreatment. Inhibition of exogenous transglutaminase by neopentyl chloroethyl nitrosourea also greatly reduced the inhibition of thymidine incorporation by UG. The data clearly indicate that UG and TG suppress blastomere immunogenicity, perhaps by a cross-linking mechanism between UG and blastomere antigens. We suggest that uteroglobin in conjunction with transglutaminase may inhibit immunorejection of embryos at about the time of implantation.
Chromatic organization of primate cones

The distribution of baboon retinal cones were mapped histochemically by light-stimulated reduction of nitroblue tetrazolium chloride. Blue cones were distributed regularly in the periphery: red and green cones were distributed randomly everywhere. The ordering of cone densities was greeen greater than red greater than blue.
Photochemistry of modified proteins. Benzophenone-containing bovine serum albumin.

— The results of exploratory and mechanistic studies of the photochemistry of poly-p-benzoyl-acetimido-bovine serum albumin, a modified protein containing photoreactive and photosensitizing groups, are reported. Specifically described are our recent findings concerning (1) the synthesis and characterization of a modified bovine serum albumin that contains benzophenone-like moieties, (2) the photochemistry of this modified protein which appears to involve photoreductive coupling of the benzophenone chromophores to the protein backbone, and (3) triplet energy transfer from modified bovine serum albumin to small molecule acceptors resulting in quenching of the photoreaction.
Lunar Base Point Design and Logistical Analysis

With the ever-changing universe that we live in, NASA would like to lead the United States into a new era of space exploration throughout the 21st century. One of the steps involved with accomplishing this mission is to develop a lunar base that can provide a leaping point to planets such as Mars. NASA has solicited the assistance of our USMA capstone group to help with the development of a lunar base design and resupply model that might help them meet their proposed completion date of 2020. Our capstone group's primary resource is The Lunar Base Handbook by Peter Eckart. We have also utilized information from Human Spaceflight: Mission Analysis and Design by Wiley Larson and Linda Pranke, as well as Peter Eckart's Parametric model of a lunar base for mass and cost estimates. We have broken down the system into four major areas of functionality: life critical, live support, living conditions, and maintenance. We then researched our fields and alternatives available, taking into consideration the technology, economics, transportation and logistics, infrastructure, and environment involved with establishing and maintaining a lunar base. We created some major comparison and analysis factors to include cost/mass, technology requirements, modularity, complexity, and reliability. We finalized the design by valuing and selecting the best alternatives and established a model of the system. We followed this up by completing a sensitivity analysis and implementation plan of the system. We have identified the most promising design decisions and started bringing them together to create our lunar base. We have also developed a parametric spreadsheet model to aid in implementation of possible resupply needs
An optimal fault-tolerant broadcasting algorithm for a hypercube multiprocessor

In this paper we describe an optimal fault-tolerant broadcasting algorithm in the presence of n-1 faulty processors in the hypercube multiprocessor. This algorithm takes log2(N)+1 steps to broadcast the message to all other processors. Our broadcasting algorithm is a procedure by which a processor can pass a message to all other processors in the network non-redundantly.
Critical fluence effects in laser propulsion

The fluence dependence of the laser ablation of selected polymers was studied within the range from 1-150 J/cm 2 . A TEA CO 2 laser operating at 10.6 μm with 300 ns main pulse length and up to 20 J pulse energy was used to ablate prepared polymer samples with single pulses of laser energy. Measurements of parameters such as the ablated mass per spot area (Δm a ), momentum coupling coefficient (C m ), specific impulse (I sp ), and internal efficiency (η i ) will be plotted as functions of fluence. Critical threshold effects observed throughout the experiments will be described in detail.
Local Radio and Microblogging: How Radio Stations in the U.S. are Using Twitter

Using a content analysis method, this study examined the way in which 111 radio stations in the U.S. are using the social network system, Twitter. Results of the study revealed that there was only a weak correlation between stations' average quarter hour share and the number of followers of stations' Twitter sites. Also, music stations had more promotional tweets, while news stations provided more news items for their audiences.
Deprofessionalization: The Case of Law in America

It is becoming increasingly evident that the conditions that fostered the growth and dominance of the professions during the early part of this century are being eroded by social change. Social, economic, and political trends are undermining claims to autonomy and monopoly by previously well-entrenched groups such as the legal profession in America. These trends include changes in the knowledge base, shifts in the composition of the profession, emerging employment patterns, consumerism, and encroachment from allied professions. The process of deprofessionalization is manifest in a variety of restrictions upon traditional prerogatives, which suggests a general weakening of the very legitimacy of the unregulated professional model of social organization.
Regioselective photodimerization of cinnamic acids in water: Templation with cucurbiturils.

Cinnamic acids upon irradiation in solution undergo geometric isomerization while dimerizing to different dimers in the crystalline state. Controlling the nature of the dimer formed upon irradiation remains a challenging task. We have aligned a variety of cinnamic acid molecules in a head-head fashion employing cucurbit[8]uril, a weakly water soluble host as a template. The water solubility of cucurbit[8]uril is enhanced by inclusion of water soluble cinnamic acids and positions the olefins in an arrangement that favors the formation of syn head-head cyclobutanes in near quantitative yields. This methodology works in both solid state as well as in aqueous solution. Irradiation of cinnamic acid complexes with γ-cyclodextrin has been carried out as a comparison. We find that while cucurbit[8]uril functions well both in solid state and aqueous solution, cyclodextrin works best as solid complexes only. Consistent with the postulated requirement of large cavities for templating olefins to dimerization, irradiation of complexes of cinnamic acid with cucurbit[7]uril resulted in only the corresponding cis isomers.
Neutrality: An Enduring Principle of the Federal Service:

Although many proponents of civil service reform question the principles of classical American public administration and specifically reject its neutral competence model of federal service, the principle of neutrality continues to be an important belief of federal career executives. This finding is based on an analysis of responses to a survey of 1,045 high-level (SES and GM-15) careerists and 242 political appointees from 15 federal organizations undertaken in November and December of 1987. As expected, Reagan political appointees profess slightly more support for the neutrality principle than their career subordinates. Still, careerist support for the principle is high and relatively uniform across organizations. The highest levels of the career bureaucracy, the Senior Executive Service, seem slightly more likely than their GM-15 subordinates to profess support for neutrality. Finally, support for this principle does not seem to improve career-noncareer relations, which instead appear to turn on the goa...
A perspective on intelligent devices and environments in medical rehabilitation

Globally, the number of people older than 65 years is anticipated to double between 1997 and 2025, while at the same time the number of people with disabilities is growing at a similar rate, which makes technical advances and social policies critical to attain, prolong, and preserve quality of life. Recent advancements in technology, including computation, robotics, machine learning, communication, and miniaturization of sensors have been used primarily in manufacturing, military, space exploration, and entertainment. However, few efforts have been made to utilize these technologies to enhance the quality of life of people with disabilities. This article offers a perspective of future development in seven emerging areas: translation of research into clinical practice, pervasive assistive technology, cognitive assistive technologies, rehabilitation monitoring and coaching technologies, robotic assisted therapy, and personal mobility and manipulation technology.
The prescription handoff in community pharmacy: A study of its form and function

Objective To describe and explore handoffs in community pharmacy. Design Descriptive, exploratory, nonexperimental study. Setting Wisconsin, August to October 2008. Participants Community pharmacists. Intervention Brief, face-to-face, semistructured interviews. Main outcome measure Information on characteristics of handoffs, including the reasons for handoffs, what kind of information is shared during handoffs, and how information is shared. Results The overarching reasons handoffs are done in community pharmacy are because some of the necessary information is confusing, contradictory, or absent, and/or the drug product is not in stock. Handoff information typically consists of a description of the problem, the current status of the problem, what information is still needed, and future steps to resolve the problem. Handoffs can occur synchronously during a shift change or asynchronously when one pharmacist signs out at the end of the day and another pharmacist opens the pharmacy the next morning. While synchronous handoffs are generally verbal in nature, asynchronous handoff information is primarily conveyed via paper or electronic notes on the dispensing computer system. Conclusion Our results suggest that handoffs do take place in community pharmacies and that the process is unstructured and variable. Future studies should fully characterize this process and explore possible strategies for improvement.
Analysis of the high growth-rate transition in Al–Si eutectic solidification

The local solidification conditions and mechanisms associated with the flake-to-fiber growth mode transition in Al–Si eutectic alloys are investigated here using Bridgman-type gradient-zone directional solidification. Resulting microstructures are examined through quantitative image analysis of two-dimensional sections and observation of deep-etched sections, showing three-dimensional microstructural features. Several microstructural parameters were investigated in an attempt to quantify this transition, and it was found that the particle aspect ratio is effective in objectively identifying the onset and completion velocity of the flake-to-fiber transition, whereas traditional spacing parameters are not effective indicators of the transition. For a thermal gradient of 7–14 K/mm, the transition was found to occur in two stages, appearing over velocity regimes from 0.10 to 0.50 mm/s and from 0.50 to 0.95 mm/s. The initial stage is dominated by in-plane plate breakup and rod formation within the plane of the plate, whereas the second stage is characterized by the onset of out-of-plane silicon rod growth, leading to the formation of an irregular fibrous structure. The boundary between the two stages is marked by widespread fibrous growth and the disappearance of the remnant flake structure, indicating a transition in the structural feature that governs the relevant diffusion length, from inter-flake spacing to inter-rod spacing.
Iterative Monte Carlo with bead-adapted sampling for complex-time correlation functions

In a recent communication [V. Jadhao and N. Makri, J. Chem. Phys. 129, 161102 (2008)], we introduced an iterative Monte Carlo (IMC) path integral methodology for calculating complex-time correlation functions. This method constitutes a stepwise evaluation of the path integral on a grid selected by a Monte Carlo procedure, circumventing the exponential growth of statistical error with increasing propagation time, while realizing the advantageous scaling of importance sampling in the grid selection and integral evaluation. In the present paper, we present an improved formulation of IMC, which is based on a bead-adapted sampling procedure; thus leading to grid point distributions that closely resemble the absolute value of the integrand at each iteration. We show that the statistical error of IMC does not grow upon repeated iteration, in sharp contrast to the performance of the conventional path integral approach which leads to exponential increase in statistical uncertainty. Numerical results on systems wit...
Her2/neu induces all-trans retinoic acid (ATRA) resistance in breast cancer cells

We observed that all-trans retinoic acid (ATRA) inhibited the growth of MCF-7 breast cancer cells, but not those transfected with HER2/NEU or its transactivating ligand HEREGULIN. This suggests that Her2/neu causes breast cancer cells to be resistant to the growth inhibitory effects of ATRA. To confirm this observation, MDA-MB-453 and BT-474 cells, which have high levels of Her2/neu and are resistant to ATRA, were incubated with the trastuzumab (Herceptin) antibody so that we could determine whether inhibition of the expression and function of Her2/neu would resensitize these cells to ATRA. Indeed, we found that MDA-MB-453 and BT-474 cells treated with trastuzumab were growth inhibitory by ATRA. We then determined whether Her2/neu uses Grb2 and Akt proteins to induce ATRA resistance. Liposome-incorporated Grb2 antisense oligonucleotides (L-Grb2) and a dominant negative (DN) AKT mutant were used to down-regulate Grb2 expression and inhibit Akt activity, respectively. When incubated with L-Grb2 or transfected with the DN AKT mutant, ATRA-resistant, Her2/neu-overexpressing cells became sensitive to ATRA. Our results indicate that Her2/neu utilizes Grb2 and Akt proteins to induce ATRA resistance in breast cancer cells. ATRA sensitivity was also correlated with RARalpha protein levels since higher RARalpha protein levels were observed in cells in which the Her2/neu pathway was inhibited.
Skeletal Muscle Amino Acid and Myofibrillar Protein mRNA Response to Thermal Injury and Infection Y. FONG, J. P. MINEI, M. A. MARANO, ET AL American Journal of Physiology 261:R536—R542, 1991

This study investigates alterations in rat skeletal muscle after burn trauma (30% body surface area, full-thickness scald injury) with or without concomitant burn wound infection (immediate postburn inoculation with Pseudomonas aeruginosa), an injury model previously described by the authors.1 The study design allowed evaluation of sequential changes in skeletal muscle membrane integrity after burn or burn-infection injury and whether these occur coordinately with changes in muscle protein mass, specific protein transcription, intracellular amino acid and electrolyte concentrations, and indices of cellular energy status. Four groups of rats were compared: animals subjected to burn injury alone (Burn), burn injury plus wound infection (BI), freely fed, unburned control animals (FF), and unburned animals pair-fed to BI (PF: to control for anorexia in the BI group). Skeletal muscle myofibrillar protein transcription (relative abundance of messenger RNA for actin and myosin heavy chain); indices of muscle mas...
Two dynamically distinct inhibitory networks in layer 4 of the neocortex

Normal operations of the neocortex depend critically on several types of inhibitory interneurons, but the specific function of each type is unknown. One possibility is that interneurons are differentially engaged by patterns of activity that vary in frequency and timing. To explore this, we studied the strength and short-term dynamics of chemical synapses interconnecting local excitatory neurons (regular-spiking, or RS, cells) with two types of inhibitory interneurons: fast-spiking (FS) cells, and low-threshold spiking (LTS) cells of layer 4 in the rat barrel cortex. We also tested two other pathways onto the interneurons: thalamocortical connections and recurrent collaterals from corticothalamic projection neurons of layer 6. The excitatory and inhibitory synapses interconnecting RS cells and FS cells were highly reliable in response to single stimuli and displayed strong short-term depression. In contrast, excitatory and inhibitory synapses interconnecting the RS and LTS cells were less reliable when initially activated. Excitatory synapses from RS cells onto LTS cells showed dramatic short-term facilitation, whereas inhibitory synapses made by LTS cells onto RS cells facilitated modestly or slightly depressed. Thalamocortical inputs strongly excited both RS and FS cells but rarely and only weakly contacted LTS cells. Both types of interneurons were strongly excited by facilitating synapses from axon collaterals of corticothalamic neurons. We conclude that there are two parallel but dynamically distinct systems of synaptic inhibition in layer 4 of neocortex, each defined by its intrinsic spiking properties, the short-term plasticity of its chemical synapses, and (as shown previously) an exclusive set of electrical synapses. Because of their unique dynamic properties, each inhibitory network will be recruited by different temporal patterns of cortical activity.
Cerebellar involvement in motor but not sensory adaptation

Predictable sensorimotor perturbations can lead to cerebellum-dependent adaptation--i.e., recalibration of the relationship between sensory input and motor output. Here we asked if the cerebellum is also needed to recalibrate the relationship between two sensory modalities, vision and proprioception. We studied how people with and without cerebellar damage use visual and proprioceptive signals to estimate their hand's position when the sensory estimates disagree. Theoretically, the brain may resolve the discrepancy by recalibrating the relationship between estimates (sensory realignment). Alternatively, the misalignment may be dealt with by relying less on one sensory estimate and more on the other (a weighting strategy). To address this question, we studied subjects with cerebellar damage and healthy controls as they performed a series of tasks. The first was a prism adaptation task that involves motor adaptation to compensate for a visual perturbation and is known to require the cerebellum. As expected, people with cerebellar damage were impaired relative to controls. The same subjects then performed two experiments in which they reached to visual and proprioceptive targets while a visuoproprioceptive misalignment was gradually imposed. Surprisingly, cerebellar patients performed as well as controls when the task invoked only sensory realignment, but were impaired relative to controls when motor adaptation was also possible. Additionally, individuals with cerebellar damage were able to use a weighting strategy similarly to controls. These results demonstrate that, unlike motor adaptation, sensory realignment and weighting are not cerebellum-dependent.
The behavior of scavenged isotopes in marine anoxic environments: 210Pb and 210Po in the water column of the Black Sea

Abstract Vertical profiles of dissolved and particulate 210Pb and 210Po were determined at two stations in the Black Sea in June 1988. Vertical fluxes of 210Pb and 210Po were also measured in the upper 150 m, using floating sediment traps. The fractionation of 210Pb between dissolved and particulate phases in the Black Sea is strongly influenced by the redox conditions in the water column. Dissolved 210Pb dominates in the oxic zone, while particulate 210Pb is the major form in the deep sulfide-rich anoxic zone. The distribution of 210Pb across the suboxic zone appears to be mainly controlled by redox cycling of manganese and iron. In the sulfide-rich layer coprecipitation of lead with iron sulfide is probably the dominant scavenging mechanism. A simple scavenging model was used to calculate the residence times of dissolved and particulate 210Pb in the oxic, suboxic, and anoxic zones. The residence times of dissolved 210Pb relative to scavenging by particles are 0.5–1, 2–3, and 3.5 years in the oxic, suboxic, and anoxic layers, respectively. The corresponding residence times of particulate 210Pb relative to particle removal processes in the same layers are 0.1, 1.5–2.5, and 8.5 years, respectively. A particle settling velocity of about 40 m y−1 was derived from the 210 Pb 226 Ra disequilibrium in the deep Black Sea. The relatively short residence times of 210Pb support the hypothesis that anoxic basins are important sites for boundary scavenging of 210Pb. The 210Po profiles indicate that biological rather than inorganic particles are the major carrier phases for polonium in the Black sea. Dissolved 210Po is deficient relative to dissolved 210Pb in the euphotic zone, suggesting preferential uptake of 210Po over 210Pb by particles residing in that layer. The residence time of dissolved 210Po, with respect to scavenging by particles in the euphotic zone, is about 200 days. Below the mid-depth of the suboxic zone, 210Po is in excess relative to 210Pb, and is thought to originate from shelf and slope sediments. Based on the magnitude of distribution coefficients (KD), the relative partitioning of lead, polonium, and thorium to particles found in the oxic and anoxic layers of the Black Sea are Po > Th > Pb and Po = Pb > Th, respectively. The dependency of KD on particle concentration suggests that colloidal phases may be important for the scavenging of these radionuclides.
Proteomics reveals age-related differences in the host immune response to sepsis.

Sepsis is commonly caused by community-acquired pneumonia (CAP) and may develop into severe sepsis, characterized by multiple organ failure. The risk of severe sepsis among CAP patients and subsequent mortality increases sharply after the age of 65. The molecular mechanisms associated with this age-related risk are not fully understood. To better understand factors involved with increased incidence and mortality of severe sepsis in the elderly, we used a nested case-control study of patients enrolled in a multicenter observational cohort of 2320 participants with CAP. We identified a total of 39 CAP patients 50–65 and 70–85 years old who did or did not develop severe sepsis. Plasma samples were obtained on presentation to the emergency department and prior to therapeutic interventions. A semiquantitative plasma proteomics workflow was applied which incorporated tandem immunoaffinity depletion, iTRAQ labeling, strong cation exchange fractionation, and nanoflow liquid chromatography coupled to high-resoluti...
Sense of community in neighborhoods as a multi‐level construct

Sense of community is a compelling construct that allows psychologists to examine fundamental questions about how individuals are connected to and influenced by their most important social settings. This investigation uses an existing database of 2,409 residents of 21 neighborhoods in a Northeastern city to examine sense of community at the neighborhood level. The investigation used a cross-levels program to examine whether sense of community can be detected at the neighborhood level. The investigation also tested the strength of the relationship of both neighborhood-level variables (i.e., physical attributes and presence of a grassroots neighborhood association) and individual-level variables (i.e., income and education) on neighborhood-level sense of community. Residents of the same neighborhood were more similar to one another than to residents of a different neighborhood on both the neighborhood-related variables and income and education. When variance attributable to the personal resources of income and education were removed, intraclass correlations for neighborhood-related attitudes (i.e., perceptions of neighborhood climate and perceptions of the ability of neighborhood residents to influence neighborhood conditions) remained significant at an alpha level of .05. However, neighborhood-related behavior (i.e., neighboring behavior and participation in a community organization) was no more similar to residents of the same neighborhood than to residents of a different neighborhood. Neither the presence of a grassroots neighborhood association nor the physical characteristics of neighborhoods examined in the investigation were significantly correlated with a sense of community. © 1999 John Wiley & Sons, Inc.
Chemistry and biology of vitamin E

Our understanding of the role of vitamin E in human nutrition, health, and disease has broadened and changed over the past two decades. Viewed initially as nature's most potent lipid-soluble antioxidant (and discovered for its crucial role in mammalian reproduction) we have now come to realize that vitamin E action has many more facets, depending on the physiological context. Although mainly acting as an antioxidant, vitamin E can also be a pro-oxidant; it can even have nonantioxidant functions: as a signaling molecule, as a regulator of gene expression, and, possibly, in the prevention of cancer and atherosclerosis. Since the term vitamin E encompasses a group of eight structurally related tocopherols and tocotrienols, individual isomers have different propensities with respect to these novel, nontraditional roles. The particular beneficial effects of the individual isomers have to be considered when dissecting the physiological impact of dietary vitamin E or supplements (mainly containing only the alpha-tocopherol isomer) in clinical trials. These considerations are also relevant for the design of transgenic crop plants with the goal of enhancing vitamin E content because an engineered biosynthetic pathway may be biased toward formation of one isomer. In contrast to the tremendous recent advances in knowledge of vitamin E chemistry and biology, there is little hard evidence from clinical and epidemiologic studies on the beneficial effects of supplementation with vitamin E beyond the essential requirement.