cssi/SciSciGPT-SciSciNet huggingface dataset:
Microbial pathway for anaerobic 5′-methylthioadenosine metabolism coupled to ethylene formation

Numerous cellular processes involving S-adenosyl-l-methionine result in the formation of the toxic by-product, 5'-methylthioadenosine (MTA). To prevent inhibitory MTA accumulation and retain biologically available sulfur, most organisms possess the "universal" methionine salvage pathway (MSP). However, the universal MSP is inherently aerobic due to a requirement of molecular oxygen for one of the key enzymes. Here, we report the presence of an exclusively anaerobic MSP that couples MTA metabolism to ethylene formation in the phototrophic bacteria Rhodospirillum rubrum and Rhodopseudomonas palustris In vivo metabolite analysis of gene deletion strains demonstrated that this anaerobic MSP functions via sequential action of MTA phosphorylase (MtnP), 5-(methylthio)ribose-1-phosphate isomerase (MtnA), and an annotated class II aldolase-like protein (Ald2) to form 2-(methylthio)acetaldehyde as an intermediate. 2-(Methylthio)acetaldehyde is reduced to 2-(methylthio)ethanol, which is further metabolized as a usable organic sulfur source, generating stoichiometric amounts of ethylene in the process. Ethylene induction experiments using 2-(methylthio)ethanol versus sulfate as sulfur sources further indicate anaerobic ethylene production from 2-(methylthio)ethanol requires protein synthesis and that this process is regulated. Finally, phylogenetic analysis reveals that the genes corresponding to these enzymes, and presumably the pathway, are widespread among anaerobic and facultatively anaerobic bacteria from soil and freshwater environments. These results not only establish the existence of a functional, exclusively anaerobic MSP, but they also suggest a possible route by which ethylene is produced by microbes in anoxic environments.
Grand Strategies of States in Anarchy: Prestige and Self-Determination

This chapter defines grand strategies of particular states as they correspond with threats to survival. Great powers are driven to strengthen their position in the world through prestige-seeking behavior. Prestige is understood as a psychological identity of great power exceptionalism. Great powers are in conflict over prestige-seeking behavior which defines their attempt to balance one another’s exceptionalism. Conversely, weak states are particularly systemically vulnerable units in anarchy. Weak state grand strategy dictates survival by any means necessary. This causes playing the field which breaks the balance of power expectation of bandwagoning. Weak states submit their political autonomy to great powers and gain aid to enable their own survival. Great powers then wrestle for control of the board.
Epidemiology and hereditary aspects of acute leukemia

Recent projections for the USA estimate that 6590 patients are diagnosed annually with acute lymphocytic leukemia (ALL) and 19,950 with acute myeloid leukemia (AML), while approximately 1430 patients die from ALL and 10,430 from AML (Siegel et al., CA Cancer J Clin 66(1):7–30, 2016). Together these forms of acute leukemia represent about 1.6% of all newly diagnosed cancers and 2.0% of all cancer deaths in the USA (Siegel et al., CA Cancer J Clin 66(1):7–30, 2016). Advances in the understanding of immunology and molecular/genetic features of the acute leukemias along with laboratory improvements in immunophenotyping and cytogenetic characterization have led to the recognition of molecularly defined subtypes of ALL and AML, targeted therapeutics, and recognition of distinct prognostic groups. The most recent World Health Organization (WHO) classification of hematopoietic malignancies considers three major categories of acute leukemia: AML and related myeloid precursor neoplasms, precursor lymphoid neoplasms (encompassing the entities previously known as ALL), and acute leukemias of ambiguous lineage (World Health Organization classification of tumours of haematopoietic and lymphoid tissues, 4th ed. Lyon: International Agency for Research on Cancer, 2008). Consistent with classifications used in cancer registries, to date most epidemiologic investigations have considered all acute leukemias combined or the broad categories of ALL and AML, although an increasing number of studies, especially those of genetic risk factors, examine cases by molecular subtype. Traditionally pediatric acute leukemias, defined either as those diagnosed at 0–14 or 0–19 years of age, have been studied separately from that in adults.
Topographical Specificity of Forebrain Inputs to the Midbrain Periaqueductal Gray: Evidence for Discrete Longitudinally Organized Input Columns

Over two decades ago it was discovered that electrical stimulation of the periaqueductal gray (PAG) caused profound analgesia (Reynolds, 1969). It was subsequently found that “PAG-analgesia” is, at least in part, mediated by opiate and neurotensin systems acting via PAG projections to the rostral medulla (Basbaum and Fields, 1984; Behbehani, 1981; Behbehani and Fields, 1979; Behbehani and Pert, 1984; Behbehani et al., 1987; Lakos and Basbaum, 1988; Reichling et al., 1988; Shipley et al., 1987). As a result of the observation that a discrete CNS structure exerted such a potent regulation of pain, much subsequent research has focused on the role of PAG in antinociception. At the same time there has been growing evidence that PAG plays a key role in the “defense reaction” (Bandler and Carrive, 1988; Bandler and Depaulis, this volume; Bandler et al., 1985a, 1991; Depaulis and Vergnes, 1986; Depaulis et al., 1989; Zhang et al., 1990), vocalization (Jurgens, 1976; Jurgens and Richter, 1986; Larson, 1985; Larson and Kistler, 1984; 1986), and in certain sexual behaviors (Ogawa et al., this volume; Sakuma and Pfaff; 1979a,b).
Climate Change and Ecology, Synergism of

Climate has varied substantially on geological timescales, and ecological systems have responded with large shifts in vegetation and animal patterns, including extinctions. Human activities that burn fossil fuels inject greenhouse gases into the atmosphere. The net effect has been to warm the global climate by approximately 0.85 °C since 1750. Human land uses such as agriculture or roads, often block species movements. The combined effects of climate changes and other human-caused stress on species collectively impact species significantly more than if each of these were simply considered separately. Many scientists have serious concerns about the need to conserve wildlife and vegetation.
Why do employees get upset about broken promises?:An examination of PCB-PCV mediators

Research on psychological contracts has not been clear on why psychological contract breach (PCB), which represents the extent to which the employee is aware of an unfulfilled obligation on the par...
Assessing the Diversity of Endogenous Viruses Throughout Ant Genomes.

Endogenous viral elements (EVEs) can play a significant role in the evolution of their hosts and have been identified in animals, plants, and fungi. Additionally, EVEs potentially provide an important snapshot of the evolutionary frequency of viral infection. The purpose of this study is to take a comparative host-centered approach to EVE discovery in ant genomes to better understand the relationship of EVEs to their ant hosts. Using a comprehensive bioinformatic pipeline, we screened all nineteen published ant genomes for EVEs. Once these EVEs were identified, we assessed their phylogenetic relationships to other closely related exogenous viruses. A diverse group of EVEs derived from ant host genomes were discovered in all screened genomes and in many cases are similar to previously identified exogenous viruses. EVEs similar to ssRNA viral proteins are the most common viral lineage throughout the ant hosts, which is potentially due to more chronic infection or more effective endogenization of certain ssRNA viruses in ants. In addition, both EVEs similar to viral glycoproteins and retrovirus-derived proteins are also abundant throughout ant genomes, suggesting their tendency to endogenize. Several of these newly discovered EVEs are found to be potentially functional within the genome. The discovery and analysis of these EVEs is essential in beginning to understand viral-ant interactions over evolutionary time.
Popular Geopolitics: Plotting an Evolving Interdiscipline

Robert A. Saunders and Vlad Strukov, eds. New York, NY: Routledge, 2018. xv and 255 pp., photos, notes, bibliography, index. $140.00 cloth (ISBN 978-0-815-38403-8); $49.46 e-Book (ISBN 978-1-351-20...
Thiamine phosphokinase deficiency and mutation in TPK1 presenting as biotin responsive basal ganglia disease.

Abstract The product of thiamine phosphokinase is the cofactor for many enzymes, including the dehydrogenases of pyruvate, 2-ketoglutarate and branched chain ketoacids. Its deficiency has recently been described in a small number of patients, some of whom had a Leigh syndrome phenotype. The patient who also had a Leigh phenotype was initially found to have a low concentration of biotin in plasma and massive urinary excretion of biotin. Despite treatment with biotin and thiamine, her disease was progressive. Mutations c.311delG and c.426G > C were found in the TPK1 gene.
Approximate Pattern Matching using Hierarchical Graph Construction and Sparse Distributed Representation

With recent developments in deep networks, there have been significant advances in visual object detection and recognition. However, some of these networks are still easily fooled/hacked and have shown "bag of features" failures. Some of this is due to the fact that even deep networks make only marginal use of the complex structure that exists in real-world images, even after training on huge numbers of images. Biology appears to take advantage of such a structure, but how? In our research, we are studying approaches for robust pattern matching using still, 2D Blocks World images based on graphical representations of the various components of an image. Such higher order information represents the "structure" of the visual object. Here we discuss how the structural information of an image can be captured in a Sparse Distributed Representation (SDR) loosely based on cortical circuits. We apply probabilistic graph isomorphism and subgraph isomorphism to our 2D Blocks World images and achieve O (1) and O (nk) complexity for an approximate match. The optimal match is an NP-Hard problem. The image labeled graph is created using OpenCV to find the object contours and objects' labels and a fixed radius nearest neighbor algorithm to build the edges between the objects. Pattern matching is done using the properties of SDRs. Our research shows the promise of applying graph-based neuromorphic techniques for pattern matching of images based on such structure.
Influence of manure application on surface energy and snow cover: model development and sensitivities.

Winter landspreading is an important part of manure management in the U.S. Upper Midwest. Although the practice is thought to lead to excessive P runoff losses, surprisingly little has been learned from field experiments or current water quality models, We captured knowledge gained from winter manure landspreading experiments by modifying a mechanistic snow ablation model to include manure. The physically based, modified model simulated the observed delay in snow cover disappearance and surface energy balance changes caused by application of the manure. Additional model simulations of surface energy balance estimates of radiation and turbulent fluxes showed that during intense melting events the manure on top of snow significantly reduced the energy available for melt of the snow underneath, slowing melt. The effect was most pronounced when snowmelt was driven by both relatively high solar radiation and turbulent heat fluxes. High absorbed shortwave radiation caused significant warming of the manure, which led to substantial losses in turbulent fluxes and longwave radiation. Simulations of snowmelt also showed that manure applications between 45 and 100 Mg ha -1 significantly reduced peak snowmelt rates, in proportion to the manure applied. Lower snowmelt rates beneath manure may allow more infiltration of meltwater compared with bare snow. This infiltration and attenuated snowmelt runoff may partially mitigate the enhanced likelihood of P runoff from unincorporated winter-spread manure.
Ethnoracial Sleep Disparities among College Students Living in Dormitories in the United States: A Nationally Representative Study

Abstract Objectives Ethnoracial disparities in sleep health across the lifecourse, may underlie other disparities in health and well-being among adults in the United States (U.S.). We evaluated if socioenvironmental stressors, which likely differ by the race/ethnicity of college students, may contribute to sleep disparities in this demographic group. Design/Measurements National Health Interview Survey data pooled from 2004 to 2017 were used to test the hypothesis that ethnoracial disparities in sleep exist among college students residing in dormitories in the U.S. Setting Nationally representative survey data. Participants A total of 2,119 college students residing in dormitories (71% White, 16% Black/African-American, 7% Hispanic/Latino, and 6% Asian) participated in the study. Results The prevalence of short sleep duration was higher among Black/African-Americans than among White students, but not among Hispanics/Latinos and Asians, after adjusting for age, gender, and region of residence. In fully adjusted models, Black/African-Americans, although no longer statistically significant after adjustments, were more likely to report short sleep duration compared with White students (adjusted prevalence ratio; [aPR] = 1.30, 95% confidence interval [CI]: 0.98-1.71). The prevalence of separate insomnia symptoms did not differ by ethnoracial group in adjusted models. Only Asian students had a higher prevalence (aPR = 1.40, 95% CI: 1.12-1.75) of nonrestorative sleep than White students. Conclusion Black/African-American but not Hispanic/Latino or Asian college students were more likely to report short sleep duration than Whites. Insomnia symptoms did not differ between groups, while Asians experienced more nonrestorative sleep. Future studies should investigate the socioenvironmental causes of disparities using longitudinal designs, larger sample sizes, better socioeconomic status (SES) indicators, and objective sleep measures.
The role of parvalbumin interneuron GIRK signaling in regulation of affect and cognition in male and female mice

ABSTRACT Pathological impairments in the regulation of affect (i.e. emotion) and flexible decision-making are commonly observed across numerous neuropsychiatric disorders and are thought to reflect dysfunction of cortical and subcortical circuits that arise in part from imbalances in excitation and inhibition within these structures. Disruptions in GABA transmission, in particular that from parvalbumin-expressing interneurons (PVI), has been highlighted as a likely mechanism by which this imbalance arises, as they regulate excitation and synchronization of principle output neurons. G protein-gated inwardly rectifying potassium ion (GIRK/Kir3) channels are known to modulate excitability and output of pyramidal neurons in areas like the medial prefrontal cortex and hippocampus, however the role GIRK plays in PVI excitability and behavior is unknown. Male and female mice lacking GIRK1 in PVI (Girk1flox/flox:PVcre) and expressing td-tomato in PVI (Girk1flox/flox:PVCre:PVtdtom) exhibited increased open arm time in the elevated plus maze, while males showed an increase in immobile episodes during the forced swim test. Loss of GIRK1 did not alter motivated behavior for an appetitive reward or impair overall performance in an operant-based attention set-shifting model of cognitive flexibility, however it did alter types of errors committed during the visual cue test. Unexpectedly, baseline sex differences were also identified in these tasks, with females exhibiting overall poorer performance compared to males and distinct types of errors, highlighting potential differences in task-related problem solving. Interestingly, reductions in PVI GIRK signaling did not correspond to changes in membrane excitability but did increase action potential firing at higher current injections in PVI of males, but not females. This is the first investigation on the role that PVI GIRK-signaling has on membrane excitability, action potential firing, and their role on affect and cognition together increasing understanding of PVI cellular mechanisms and function.
Building Systemic Capacity to Scale and Sustain Equity in Computer Science through Multi-Stakeholder Professional Development

The CSforALL movement has made great strides preparing teachers in computer science (CS) with professional development (PD) toward broadening participation in computing. These opportunities develop teachers' understanding of CS content, alongside culturally-relevant practices and equitable access. However, while a focus on teachers is necessary, it is not sufficient for systemic, scalable, and equitable implementation. Comprehensive PD programs need to include teachers, school counselors, and administrators. This paper uncovers a statewide research-practice partnership's approach to a replicable multi-stakeholder PD model that addresses the following research question: How can a comprehensive CSforALL model effectively engage teachers, counselors, and administrators to work in unison to ensure equity sits at the heart of scaling and sustaining CS education for all students? A university-district research-practice partnership developed a week-long professional learning experience for teachers, counselors, and administrators that linked equity at the classroom, school/district, and policy levels. With the intentions of iteratively improving on the PD and learning about attendees” CS education interests and experiences, the RPP collected and analyzed observations, interviews, and surveys. Findings reveal (1) a multi-stakeholder comprehensive PD model has positive impacts for the capacity-building of CS education leaders; and (2) a focus on equity across all strands of the PD program develops a better understanding of why equity needs to be at the center of CS implementation, allowing different stakeholders to work together to recognize collaboration is needed to respond to the challenges faced at each level of implementation.
Targeted degradation of the oncogenic phosphatase SHP2

Abstract SHP2 is a protein tyrosine phosphatase that plays a critical role in the full activation of the Ras/MAPK pathway upon stimulation of receptor tyrosine kinases (RTKs), which are frequently amplified or mutationally activated in human cancer. In addition, activating mutations in SHP2 result in developmental disorders and hematologic malignancies. Several allosteric inhibitors have been developed for SHP2 and are currently in clinical trials. Here, we report the development and evaluation of a SHP2 PROTAC created by conjugating RMC-4550 with pomalidomide using a PEG linker. This molecule is highly selective for SHP2, induces degradation of SHP2 in leukemic cells at sub-micromolar concentration, inhibits MAPK signaling, and suppresses cancer cell growth. SHP2 PROTACs serve as an alternative strategy for targeting ERK-dependent cancers and are useful tools alongside allosteric inhibitors for dissecting the mechanisms by which SHP2 exerts its oncogenic activity.
Health literacy mediates the effects of educational attainment on online pharmacy navigation skills in older adults with HIV disease.

The Internet serves an increasingly critical role in health behaviors for older adults with chronic medical conditions. Guided by theories of health behaviors and literacy, this study examined whet...
A Design Flow for Mapping Spiking Neural Networks to Many-Core Neuromorphic Hardware

The design of many-core neuromorphic hardware is getting more and more complex as these systems are expected to execute large machine learning models. To deal with the design complexity, a predictable design flow is needed to guarantee real-time performance such as latency and throughput without significantly increasing the buffer requirement of computing cores. Synchronous Data Flow Graphs (SDFGs) are used for predictable mapping of streaming applications to multiprocessor systems. We propose an SDFG-based design flow for mapping spiking neural networks (SNNs) to many-core neuromorphic hardware with the objective of exploring the tradeoff between throughput and buffer size. The proposed design flow integrates an iterative partitioning approach, based on Kernighan-Lin graph partitioning heuristic, creating SNN clusters such that each cluster can be mapped to a core of the hardware. The partitioning approach minimizes the inter-cluster spike communication, which improves latency on the shared interconnect of the hardware. Next, the design flow maps clusters to cores using an instance of the Particle Swarm Optimization (PSO), an evolutionary algorithm, exploring the design space of throughput and buffer size. Pareto optimal mappings are retained from the design flow, allowing system designers to select a Pareto mapping that satisfies throughput and buffer size requirements of the design. We evaluated the design flow using five large-scale convolutional neural network (CNN) models. Results demonstrate 63% higher maximum throughput and 10% lower buffer size requirement compared to state-of-the-art dataflow-based mapping solutions.
Kinetic tracking of Plasmodium falciparum antigen presentation reveals determinants of protein export and membrane insertion

Abstract Intracellular malaria parasites export many proteins into their host cell, inserting several into the erythrocyte plasma membrane to enable interactions with their external environment. While static techniques have identified some surface-exposed proteins, other candidates have eluded definitive localization and membrane topology determination. Moreover, both export kinetics and the mechanisms of membrane insertion remain largely unexplored. We introduce Reporter of Insertion and Surface Exposure (RISE), a method for continuous nondestructive tracking of antigen exposure on infected cells. RISE utilizes a small 11 aa NanoLuc fragment inserted into a target protein and detects surface exposure through high-affinity complementation. We tracked insertion of CLAG3, a malaria parasite protein linked to nutrient uptake, throughout the P. falciparum cycle in human erythrocytes. Our approach also revealed key determinants of trafficking and surface exposure. Removal of a C-terminal transmembrane domain aborted export. Unexpectedly, certain increases in the exposed reporter size improved surface exposure by up to 50-fold, revealing that both size and charge of the extracellular epitope influence membrane insertion. Insertion of parasite proteins at the host cell surface and antigen accessibility is regulated by multiple factors, enabling intracellular parasite survival and immune evasion under a broad range of conditions.
Rare Synchronous Gastrointestinal Plasmacytomas of Colon and Stomach

Gastrointestinal (GI) plasmacytomas, though relatively uncommon, can occur with or without multiple myeloma. The small intestine is the most commonly involved GI site, followed by stomach, colon, and esophagus. Synchronous plasmacytomas involving 2 anatomically distinct regions of gastrointestinal tract have never been reported in the literature. We report a case of a multiple myeloma patient who had acute-onset hematochezia and was found to have synchronous plasmacytomas of the colon and stomach.
Human tumor xenografts in nude mice are not always of human origin: A warning signal

thymic nude mice and rats provide an excellent opportunity tostudy the in vivo biology of human cancer cells. It is now acommon practice to implant human cancer cells (fresh as well as longterm established) into athymic nude mice for studying experimentalmetastasis, selecting clones with different tumorigenic and metastaticproperties, monitoring growth in therapeutic trials, investigating cell-to-cell interactions between tumor and stromal cells, and, ﬁnally,studying in vivo carcinogenesis.
Activity-dependent scaling of quantal amplitude in neocortical neurons

Information is stored in neural circuits through long-lasting changes in synaptic strengths. Most studies of information storage have focused on mechanisms such as long-term potentiation and depression (LTP and LTD), in which synaptic strengths change in a synapse-specific manner. In contrast, little attention has been paid to mechanisms that regulate the total synaptic strength of a neuron. Here we describe a new form of synaptic plasticity that increases or decreases the strength of all of a neuron's synaptic inputs as a function of activity. Chronic blockade of cortical culture activity increased the amplitude of miniature excitatory postsynaptic currents (mEPSCs) without changing their kinetics. Conversely, blocking GABA (gamma-aminobutyric acid)-mediated inhibition initially raised firing rates, but over a 48-hour period mESPC amplitudes decreased and firing rates returned to close to control values. These changes were at least partly due to postsynaptic alterations in the response to glutamate, and apparently affected each synapse in proportion to its initial strength. Such 'synaptic scaling' may help to ensure that firing rates do not become saturated during developmental changes in the number and strength of synaptic inputs, as well as stabilizing synaptic strengths during Hebbian modification and facilitating competition between synapses.
Purification and properties of a sulfate-binding protein from Salmonella typhimurium.

Abstract Sulfate is bound firmly to Salmonella typhimurium. The binding ability is repressible. The binding site is located near the cell surface, and has been suggested as playing a role in active transport of sulfate. A simple procedure for obtaining the sulfate-binding material in homogeneous form is reported here. The material has a molecular weight of 32,000 and is of typical amino acid composition, except that it lacks the sulfur-containing amino acids. No cofactor or energy requirements were found. One sulfate ion is bound per molecule at saturation. The dissociation constant is low (as low as 0.02 µm), and is highly dependent on ionic strength.
Effect of testosterone replacement or duration of castration on baroreflex bradycardia in conscious rats.

In this study, we tested the hypothesis that 17β-estradiol contributes to testosterone-mediated restoration of baroreflex-mediated bradycardia in short-term (3 weeks) castrated rats. Further, a reported increase in serum testosterone after long-term (6 weeks) castration constituted a basis for testing the hypothesis that a spontaneous increase in serum testosterone or androstenedione in this model causes a commensurate increase in baroreflex-mediated bradycardia. Testosterone (1 week) replacement enhanced baroreflex-mediated bradycardia in short-term castrated rats without changing 17β-estradiol level. A spontaneous recovery of baroreflex-mediated bradycardia occurred following long-term castration, although circulating testosterone and androstenedione remained suppressed. The data suggest: 1) 17β-Estradiol does not contribute to testosterone restoration of the baroreflex-mediated bradycardia in short-term castrated rats. 2) The long-term modulation of baroreflex-mediated bradycardia occurs independent of androgens, or the baroreflex mechanism may become adapted to low levels of circulating androgens.
A Comparative Study of Various Model-Theoretic Treatments of Negation: A History of Formal Negation

There are different treatments of the semantics of negation in non-classical logics, the most familiar of which is probably the Kripke definition of negation for intuitionistic logic. In two recent papers I have explored generalizations of Goldblatt’s semantics for negation in orthologic (which uses the perp relation), and related these to the Kripke definition of negation for intuitonistic logic, and to the definition of De Morgan negation in relevance logic (which standardly uses the ‘star operator’ *). The present paper in part surveys this earlier work, but the main focus is to connect the alternative four-valued semantics of De Morgan negation (using ‘overdetermined’ and ‘underdetermined’ truth values) to the star semantics (and hence indirectly to the perp semantics). This connection is based on semi-published work of mine from the 1960’s.
Stimulation of nuclear RNA polymerase I activity by a soluble factor isolated from young rat liver nuclei

A stimulatory factor enhancing the normally depressed activity of RNA polymerase I in nuclei isolated from 14 month old rats was prepared from rat liver nuclei derived from rats up to 5 months of age. This “factor”, which exhibits cyclic AMP independent protein kinase activity, efficiently utilizes casein as a substrate, but not histone.
Penetrating orbitocranial trauma in the absence of an externally visible entry wound

The case of a six-year-old boy who sustained penetrating orbitocranial trauma is presented. This case is particularly unusual as there was no externally visible entry wound.
A numerical method based on the Fourier-Fourier transform approach for modeling 1-D electron plasma evolution

A numerical method is presented for studying one-dimensional electron plasma evolution under typical interplanetary conditions. The method applies the Fourier-Fourier transform approach to a plasma model that is a generalization of the electrostatic Vlasov-Poisson system of equations. Conservation laws that are modified to include the plasma model generalization and also the boundary effects of nonperiodic solutions are given. A new conservation law for entropy in the transformed space is then introduced. These conservation laws are used to verify the numerical solutions. A discretization error analysis is presented. Two numerical instabilities and the methods used for their suppression are treated. It is shown that in interplanetary plasma conditions, the bump-on-tail instability produces significant excitation of plasma oscillations at the Bohm-Gross frequency and its second harmonic. An explanation of the second harmonic excitation is given in terms of wave-wave coupling during the growth phase of the instability.
Novel supermultiplets of SU (2, 2|4) and the AdS5/CFT4 duality☆

Abstract We continue our study of the unitary supermultiplets of the N = 8 d = 5 anti-de Sitter (AdS5) superalgebra SU(2,2|4), which is the symmetry algebra of type IIB superstring theory on AdS5 × S5. SU(2, 2|4) is also the N = 4extended conformal superalgebra in d = 4. We show explicitly how to go from the compact SU(2) x SU(2) x U(1) basis to the non-compact SL(2, C ) x D basis of the positive (conformal) energy unitary representations of the conformal group SU(2, 2) in d = 4. The doubleton representations of the AdS5 group SU(2, 2), which do not have a smooth Poincare limit in d = 5, are shown to represent fields with vanishing masses in four-dimensional Minkowski space, i.e. on the boundary of AdS5, where SU(2, 2) acts as conformal group. The unique CPT self-conjugate irreducible doubleton supermultiplet of SU(2, 2|4) is simply the cN = 4 Yang-Mills supermultiplet in d = 4. We study some novel short non-doubleton supermultiplets of SU(2, 2|4)that have spin range 2 and that do not appear in the Kaluza-Klein spectrum of type IIB supergravity or in tensor products of the N = 4 Yang-Mills supermultiplet with itself. These novel supermultiplets can be obtained from tensoring chiral doubleton supermultiplets,some of which we expect to be related to the massless limits of 1/4 BPS states. Hence, these novel supermultiplets may be relevant to the solitonic sector of IIB superstring and/or (p, q) superstrings over AdS5 x S5.
Calcium sensing receptor down-regulates malignant cell behavior and promotes chemosensitivity in human breast cancer cells.

The function of Ca2+ and the calcium sensing receptor (CaSR) in breast epithelium and its relationship to mammary carcinogenesis is poorly understood. In this study, we determined the function of this ligand receptor system in regulating the biologic properties of the estrogen receptor-positive MCF-7 and the estrogen receptor-negative MDA-MB-435 human breast cancer cells. Physiologic concentration of extracellular Ca2+ (by comparison to cells cultured in control low Ca2+ medium) down-modulated cellular proliferation, cellular invasion and growth in soft agarose in both of these cell lines. Physiologic concentration of extracellular Ca2+ also down-modulated the expression of the anti-apoptotic protein survivin, survivin gene transcriptional activity, survivin mRNA expression and promoted a cytotoxic response to paclitaxel. These responses to extracellular Ca2+ were found to require CaSR expression because knocking down CaSR expression in these cells abrogated the cellular responses to extracellular Ca2+. Each cell line was found to contain small subpopulations that did not express CaSR but expressed a higher level of survivin. These subpopulations were relatively resistant to paclitaxel by comparison to cells that expressed CaSR with a lower level of survivin expression. It is concluded that extracellular Ca2+ and CaSR may constitute a robust ligand-receptor system in regulating the biologic phenotype of breast epithelial cells and loss of CaSR expression may promote malignancy and resistance to cytotoxic drugs.
A mesoscale model of DNA and its renaturation.

A mesoscale model of DNA is presented (3SPN.1), extending the scheme previously developed by our group. Each nucleotide is mapped onto three interaction sites. Solvent is accounted for implicitly through a medium-effective dielectric constant and electrostatic interactions are treated at the level of Debye-Huckel theory. The force field includes a weak, solvent-induced attraction, which helps mediate the renaturation of DNA. Model parameterization is accomplished through replica exchange molecular dynamics simulations of short oligonucleotide sequences over a range of composition and chain length. The model describes the melting temperature of DNA as a function of composition as well as ionic strength, and is consistent with heat capacity profiles from experiments. The dependence of persistence length on ionic strength is also captured by the force field. The proposed model is used to examine the renaturation of DNA. It is found that a typical renaturation event occurs through a nucleation step, whereby an interplay between repulsive electrostatic interactions and colloidal-like attractions allows the system to undergo a series of rearrangements before complete molecular reassociation occurs.
Case Study: Adverse Effects of Smoking Marijuana While Receiving Tricyclic Antidepressants

Increasingly, children and adolescents are being treated for underlying psychopathology commonly associated with the psychoactive substance use disorders. Despite this apparent increase in using medication, little is known about the interaction of drugs of abuse with the psychotropic medications. The authors describe four cases of male adolescents aged 15 to 18 years being treated with a tricyclic antidepressant for attention-deficit hyperactivity disorder who manifested transient cognitive changes, delirium, and tachycardia after smoking marijuana.
Materials Chemistry of Chiral Macromolecules. 2. Solid-State Structures

Molecular organization in the solid state of a homologous series of chiral and achiral polymers [OPhCH 2 (CH 2 ) x CHRCH 2 PhCO] n (x= 3,4, R= H, CN) was studied by electron microscopy and electron diffraction. All polymers of the series had periodic molecular backbones and some contained a stereocenter substituted by nitrile groups every 16 or 17 atoms along the chain. An aliphatic unit served as a spacer between aromatic units and was part of the repeats in all polymers. This spacer contained either an even or odd number of carbons in order to generate a preference for extended or nonextended conformers, respectively. Enantiomeric enrichment of chains resulted in the formation of crystals but diastereomeric chains with even spacer formed a phase of intermediate order and those with odd spacer formed an amorphous material. Enantiomerically enriched chains are also board-shaped and organize edge-to-edge, a feature definitely not observed in one of the two unsubstituted (achiral) homologous chains studied here. The global informational traits of chains determined ifextended-chain or folded-chain crystals formed
Mitochondrial Malate Dehydrogenase: Reversible Denaturation Studies

The malate dehydrogenase isoenzymes from the mitochondria of chicken hearts have been partially resolved into separate pools. Reversible denaturation, in concentrated guanidine hydrochloride, does not change the isoenzyme distribution in each pool. This result suggests that the electrophoretic differences among the isoenzymes are not solely conformational in origin.
Participation of a persistent sodium current and calcium-activated nonspecific cationic current to burst generation in trigeminal principal sensory neurons

The properties of neurons participating in masticatory rhythmogenesis are not clearly understood. Neurons within the dorsal trigeminal principal sensory nucleus (dPrV) are potential candidates as c...
Detection of 180 kDa proteins in electroplax sodium channel preparations

1. Co-isolating proteins (M(r) 170,000-220,000) from sodium channel preparations made from the electric organ of the electric eel (Electrophorus electricus) were detected on Western blots using monoclonal antibodies. 2. Similar protein patterns were seen on immunoblots containing immunoprecipitated protein from eel muscle and brain tissues but not heart. 3. These co-isolating proteins could be separated from the mature TTX-sensitive channel protein (M(r) 280,000) using a lentil lectin-Sepharose column. 4. The 180 kDa proteins do not appear to be channel-related and can be detected as contaminants in electroplax sodium channel preparations using the monoclonal antibodies described here.
Multiple Access Schemes for Lunar Missions

Two years ago, the NASA Coding, Modulation, and Link Protocol (CMLP) study was completed. The study, led by the authors of this paper, recommended codes, modulation schemes, and desired attributes of link protocols for all space communication links in NASA's future space architecture. Portions of the NASA CMLP team were reassembled to resolve one open issue: the use of multiple access (MA) communication from the lunar surface. The CMLP-MA team analyzed and simulated two candidate multiple access schemes that were identified in the original CMLP study: Code Division MA (CDMA) and Frequency Division MA (FDMA) based on a bandwidth-efficient Continuous Phase Modulation (CPM) with a superimposed Pseudo-Noise (PN) ranging signal (CPM/PN). This paper summarizes the results of the analysis and simulation of the CMLP-MA study and describes the final recommendations.
New method for reduction of gonadal irradiation of dental patients

A pinhole camera on the lap of a phantom body was used to disclose the sources of x-radiation that expose the gonadal region of the dental patient. A short, open-ended, shielded x-ray cone, used with a dental x-ray machine oper­ ated with 65 kvp, reduces by almost one half, gonadal exposure. O pen-ended shielded cones easily may be substituted for the pointed plastic cones that are standard equipment on existing dental x-ray units.
Predominant Bacteria in the Rumen of Cattle on Bloat-Provoking Ladino Clover Pasture

Summary A study was made on the microorganisms in the rumen of six yearling steers pastured on bloat-provoking Ladino clover. Three animals were selected for study on the basis of being good bloaters and three were nonbloaters. Studies on the bloaters were made before and 24 hr. after they were treated orally with 50mg. of procaine penicillin to prevent bloat. There were no significant differences between animal groups in pH of ruminal contents, counts of cellulolytic bacteria, total anaerobic bacterial counts, or the occurrence of 11 presumptively identified bacterial groups. Counts of facultatively anaerobic streptococci were significantly depressed in the penicillin-treated group, but no other effects of treatment appeared to be significant. The means of the total anaerobic bacterial counts of the bloaters were higher than those of the two other groups, but the difference only approached significance. It is evident that the occurrence of bloat in animals consuming Ladino clover is not related to large differences in the numbers or species of ruminal microorganisms. The bacterial flora of the rumen of these Ladino clover-pastured steers, culturable in rumen fluid agar medium, differed somewhat from usual, in that the total anaerobic counts were high (5.8-8.0 billion per gram), the proportions of cellulolytic bacteria (ruminococci and Bacteroides succinogenes ) were very low, a species of anaerobic homofermentative lactobacilli was among the predominant bacteria, and the proportions of the genus Butyrivibrio were high and those of the genus Lachnospira were unusually high.
Human and environmental health : sustainable design for the NICU

The 6th edition of the Recommended Standards for Newborn Intensive Care Unit (NICU) Design includes, for the first time, concerns related to sustainability. Environmental responsibility in healthcare had its beginnings in the late-1980s with an awareness of the toxic qualities of mercury and the need to remove it from hospital environments. Since that time, environmental activism in healthcare has grown to include efforts to construct ‘green’ buildings, incorporate sustainable practice and apply environmentally responsible purchasing. Language inserted into Standards 8 and 18–21 is intended to extend sustainable design and practice not only in the design of space in the NICU but also in the selection of materials such as floor surfaces, wall coverings, furnishings and ceiling finishes. This paper includes a number of resources that will not only assist with application of the standards, but also with expanding knowledge of issues related to the development of healthcare settings that are not harmful to either human or environmental health.
Accuracy of video frame size forecasting

We experimentally explore the forecast accuracy of three forecast model types, namely (i) Auto-Regressive (AR), (ii) Moving Average (MA), and (iii) Exponentially Weighted Moving Average (EWMA). Specifically, we use a set of five MPEG-4 video traces and measure the Normalized Mean Squared Error (NMSE) for each of the model types with varying model parameters. We find that increasing model order is not beneficial for I and P frame size forecasting, but is beneficial to B frame size forecasting. Most importantly, we find that the forecast accuracy has the strongest dependence on the statistical properties of the video content itself. It appears that the forecast accuracy is not dependent on the forecast model properties but rather strictly dependent on the logical and statistical properties of the content.
Ramp Technique for DC Partial Discharge Testing

A stepwise ramp technique has been used successfully in direct current (dc) partial discharge (PD) testing on high voltage components and on resin-packaged HV devices such as the Faint Object Camera for the Space Telescope. PD data is acquired separately on part-way ramps to rated voltage and on the intermediate voltage plateaus. For test specimen intended for dc service, this ramp method gives more information about insulation integrity than purely quiescent dc measurements. This is especially true for specimens of high resistivity which causes the discharge frequency to be deceptively low at constant dc voltage. By contrast, during ramping upwards the voltage distribution is capacitive, and the PD behavior resembles that of an ac test. This gives many more pulses in the voids, and without the undesirable heat produced if 60 Hz ac were applied. PD histograms are presented on various materials, with and without intentional defects. Influence of test parameters such as ramping speed are discussed. Experience with a variety of samples and commercial HV capacitors, as well as their life test performance, can lead to approximate acceptance/rejection criteria.
Parallel Monte Carlo simulation in the canonical ensemble on the graphics processing unit

Graphics processing units (GPUs) offer parallel computing power that usually requires a cluster of networked computers or a supercomputer to accomplish. While writing kernel code is fairly straightforward, achieving efficiency and performance requires very careful optimisation decisions and changes to the original serial algorithm. We introduce a parallel canonical ensemble Monte Carlo (MC) simulation that runs entirely on the GPU. In this paper, we describe two MC simulation codes of Lennard-Jones particles in the canonical ensemble, a single CPU core and a parallel GPU implementations. Using Compute Unified Device Architecture, the parallel implementation enables the simulation of systems containing over 200,000 particles in a reasonable amount of time, which allows researchers to obtain more accurate simulation results. A remapping algorithm is introduced to balance the load of the device resources and demonstrate by experimental results that the efficiency of this algorithm is bounded by available GPU...
Induction of Mucosal and Systemic Responses against Human Immunodeficiency Virus Type 1 Glycoprotein 120 in Mice after Oral Immunization with a Single Dose of a Salmonella-HIV Vector

Previous studies from our group showed that a Salmonella-HIV vector vaccine that expressed recombinant HIV-1 envelope protein gp120 stably in the vector cytoplasm elicited type 1 helper T cell (Th1...
Gene expression-based classification of nonseminomatous male germ cell tumors

Male adult germ cell tumors (GCTs) comprise two major histologic groups: seminomas and nonseminomas. Nonseminomatous GCTs (NSGCTs) can be further divided into embryonal carcinoma (EC), teratoma (T), yolk sac tumor (YS), and choriocarcinoma (CC) on the basis of the lineage differentiation that they exhibit. NSGCTs frequently present as mixed tumors consisting of two or more histological subtypes, often limiting correlative studies of clinical and molecular features to histology. We sought to develop a molecular classifier that could predict the predominant histologic subtype within mixed NSGCT tumor samples. The expression profiles of 84 NSGCTs (42 pure and 42 mixed) and normal age-matched testes were obtained using Affymetrix microarrays. Using prediction analysis for microarrays, we identified 146 transcripts that classified the histology of pure NSGCTs samples with 93% accuracy. When applied to mixed NSGCTs, the classifier predicted a histology that was consistent with one of the reported components in 93% of cases. Among the predictive transcripts were CGB (high in CC), LCN2 (high in T), BMP2 (high in YS), and POU5F1 (high in EC). Thus, the expression-based classifier accurately assigned a single predominant histology to mixed NSGCTs, and identified transcripts differentially expressed between histologic components with relevance to NSGCT differentiation.
Comparison of theoretical models of laser ablation of polyimide with experimental results

Abstract The results of detailed calculations of the etch rates for pulsed UV laser ablation of polyimide at 308 nm using several proposed theoretical models of the process are compared with experimental results. The theories which indicate that the etch depth per pulse is dependent on the fluence, and not the peak intensity of the laser pulse, are consistent with the experimental data for laser pulse widths of 7–500 ns. The implication of the results on various aspects of the models is discussed.