cssi/SciSciGPT-SciSciNet huggingface dataset:
Multiple-description video coding through adaptive segmentation

Multiple description video coding is one method that can be used to reduce detrimental effects caused by transmission over lossy packet networks. In a multiple description system, a video sequence is segmented into two or more complimentary streams in such a way that each stream is independently decodable. When combined, the streams provide the highest level of quality, yet if one of the streams is lost or delivered late the video can be played out with only a slight reduction in overall quality. Each approach to multiple description coding consists of a tradeoff between compression efficiency and robustness. How efficiently each method achieves this tradeoff depends on the level of quality and robustness desired and on the characteristics of the video itself. Previous approaches to multiple description coding have made the assumption that a single segmentation method would be used for an entire sequence. Yet, the optimal method of segmentation can vary depending on the goals of the system, it can change over time, and it can vary within a frame. This work introduces a unique approach to multiple description coding through the use of adaptive segmentation. By selecting from a set of segmentation methods, the system adapts to the local characteristics of the video and maximizes tradeoff efficiency. We present an overview of this system and analyze its performance on real video sequences.
An Extended Peierls-Hubbard Model of Halogenbridged Transition Metal Chain Complexes

Abstract Model calculations are described for both pure (MX) and mixed-halide (MXxX′1-x) halogen (X)-bridged transition metal (M) linear chain complexes in terms of an extended Peierls-Hubbard, tight-binding Hamiltonian with ¾-filling of two-bands. Both inter- and intra-site electron-phonon coupling are included as well as various electron correlations. Calculated properties include electronic (optical absorption), lattice dynamic (IR, Raman) and spin (ESR) signatures for the ground states, localized excited states produced by impurities, doping or photo-excitation-excitons, polarons, bipolarons, solitons; and the edge states (which occur in mixed-halide crystals, e.g. PtClxBr1-x). Adiabatic molecular dynamics is used to explore photodecay channels.
Preclinical Assessment of Lisdexamfetamine as an Agonist Medication Candidate for Cocaine Addiction: Effects in Rhesus Monkeys Trained to Discriminate Cocaine or to Self-Administer Cocaine in a Cocaine Versus Food Choice Procedure

Background: Chronic amphetamine treatment decreases cocaine consumption in preclinical and human laboratory studies and in clinical trials. Lisdexamfetamine is an amphetamine prodrug in which L-lysine is conjugated to the terminal nitrogen of d -amphetamine. Prodrugs may be advantageous relative to their active metabolites due to slower onsets and longer durations of action; however, lisdexamfetamine treatment’s efficacy in decreasing cocaine consumption is unknown. Methods: This study compared lisdexamfetamine and d -amphetamine effects in rhesus monkeys using two behavioral procedures: (1) a cocaine discrimination procedure (training dose = 0.32mg/kg cocaine, i.m.); and (2) a cocaine-versus-food choice self-administration procedure. Results: In the cocaine-discrimination procedure, lisdexamfetamine (0.32–3.2mg/kg, i.m.) substituted for cocaine with lower potency, slower onset, and longer duration of action than d -amphetamine (0.032–0.32mg/kg, i.m.). Consistent with the function of lisdexamfetamine as an inactive prodrug for amphetamine, the time course of lisdexamfetamine effects was related to d -amphetamine plasma levels by a counter-clockwise hysteresis loop. In the choice procedure, cocaine (0–0.1mg/kg/injection, i.v.) and food (1g banana-flavored pellets) were concurrently available, and cocaine maintained a dose-dependent increase in cocaine choice under baseline conditions. Treatment for 7 consecutive days with lisdexamfetamine (0.32–3.2mg/kg/day, i.m.) or d -amphetamine (0.032–0.1mg/kg/h, i.v.) produced similar dose-dependent rightward shifts in cocaine dose-effect curves and decreases in preference for 0.032mg/kg/injection cocaine. Conclusions: Lisdexamfetamine has a slower onset and longer duration of action than amphetamine but retains amphetamine’s efficacy to reduce the choice of cocaine in rhesus monkeys. These results support further consideration of lisdexamfetamine as an agonist-based medication candidate for cocaine addiction.
Policy implications of alcohol and tobacco demand in Poland

Abstract Demand models for alcohol and tobacco have been estimated from annual data providing point elasticity estimates. The results indicate that vodka and tobacco consumption are price-inelastic. The importance of revenues from alcohol and tobacco to the government budget was emphasized because of a chronic budget deficit. The results suggest that revenue from tobacco sales would increase following cigarette price increases. However, the long-run solution should lead to increased economic activity that lowers the importance of alcohol and tobacco sales and achieve a socially desired decrease in consumption of alcohol and tobacco.
Single oral immunization with replication deficient recombinant adenovirus elicits long-lived transgene-specific cellular and humoral immune responses.

Abstract Oral–gastric delivery of vaccines is a preferred route of immunization and is particularly relevant to the development of vaccine-vector systems. We have investigated the ability of a replication deficient (E1-deleted) adenovirus construct (RAd68), which efficiently expresses the measles virus nucleocapsid (N) protein under the control of the strong HCMV IE promoter, to elicit antibody and cytotoxic T cell (CTL) responses in mice following intragastric administration. Measles virus N protein-specific CTL memory and serum antibody responses were analyzed in a total of 140 mice at time points 2–51 weeks after immunization either with a single dose of 10 8 pfu RAd68 or with a fivefold higher dose. Of the 20 animals analyzed in the first 4-week period following low-dose immunization, 6 mounted low-level splenic CTL responses while 13 animals had CTL in the mesenteric lymph nodes. Splenic CTL responses were largely undetectable at later times. Only 23% of low-dose-immunized mice made serum antibody responses and these were generally of low magnitude and frequently of short duration. In contrast, the majority of animals immunized orally with 5 × 10 8 pfu RAd68 mounted splenic CTL responses (70%) and/or antibody responses (89%). Notably, these responses were stronger and of greater duration than those seen following immunization at the lower dose. Gut mucosal immunization with replication deficient adenoviruses is a promising approach, not only for the development of complementary measles vaccine strategies which may be required for measles virus eradication, but also generally for vaccination against other infections.
Use of catalytic topoisomerase II inhibitors to probe mechanisms of chemical-induced clastogenicity in Chinese hamster V79 cells.

Determination of the clastogenic potential of new chemical entities, particularly pharmaceuticals, is an important part of the overall safety assessment of such drugs. It is appreciated that clastogenicity can arise from perturbation of many different cellular processes distinct from direct DNA/drug interactions. One such alternative clastogenic process is inhibition of DNA topoisomerase II, during which process the topoisomerase/DNA/drug ternary complex forms stable DNA double-strand breaks (cleavable complex), which become templates for recombinational, mutagenic, and chromosomal fragmentation events. Without extensive experimentation, it is generally not possible to distinguish clastogenicity arising from direct drug/ DNA interaction from that arising from inhibition of topoisomerase II. In the present investigation, we demonstrate that specific catalytic inhibitors of DNA topoisomerase II reduce the clastogenicity of topoisomerase poisons but not that arising via non-topoisomerase-dependent mechanisms. In particular, it is shown that catalytic topoisomerase II inhibitors such as chloroquine, sodium azide, and A-74932, as well as certain intercalating agents such as 9-aminoacridine and ethidium bromide, strongly antagonize the formation of micronuclei induced by the DNA gyrase inhibitor clinafloxacin and the antitumor topoisomerase II poison etoposide. These catalytic inhibitors are also shown to antagonize the clastogenicity of experimental compounds and novel pharmaceuticals presumed to be DNA intercalating agents by virtue of their response in a cell-based bleomycin amplification assay. We extend our previous hypothesis, suggesting that the clastogenicity of some nonstructurally alerting drugs may be due to an as yet unappreciated propensity for DNA intercalation. It is further proposed that intercalation-dependent inhibition of DNA topoisomerase II may be responsible for this clastogenicity and that this may be detected in intact mammalian cells with the use of catalytic topoisomerase inhibitors.
System-level modeling and experimental verification for the CMOS MEMS microphone

A MEMS microphone system consists of subsystems such as chamber acoustics, structural dynamics, capacitor electrostatics and read-out circuitry. No matter fabricating the whole system with SoC (system on chip) by CMOS process or with SiP (system in packaging), the capability of system-level modeling is the prerequisite to design a microphone with high performances. Unlike using circuit analogy in published studies, this research builds all subsystems with SIMULINK® platform on a signal-flow base, which promises not only the nonlinear interactions between subsystems but also a deeply physical insight into the design investigation. Compared with experimental measurement, this modeling shows good agreement and can catch important features in frequency response such as circuit-induced low-frequency decaying and packaging-induced Helmholtz's resonance.
Gender disparities in neonatal outcome of near-term preterm births following preterm premature rupture of membranes (PPROM): Do they exist?

PHELAN, CORTNEY KIRKRNDALL, LISA KORST, GILBERT MARTIN, Citrus Valley Medical Center, OB/GYN, West Covina, California, Childbirth Injury Prevention Foundation, Pasadena, California, USC Keck School of Medicine, OB/GYN, Los Angeles, California, Citrus Valley Medical Center, Neonatology, West Covina, California OBJECTIVE: To examine the relationship between acute birth asphyxia and hematologic injury among neonates with permanent neurologic impairment. STUDY DESIGN: Study cases were from the population defined in a prior publication (J. Matern. Fet-Med 1999;8:101). Acute birth asphyxia was defined as a sudden, rapid, and sustained deterioration of the FHR that lasted until delivery from a previously normal and reactive FHR pattern or a bradycardia on admission to the hospital. Hematologic injury as defined in a prior publication (Obstet. Gynecol. 2002;99:688) were as follows: nucleated red blood cells (NRBC) count R26 per 100 white blood cells (%); platelet count %100,000 per mm within 5 days of birth in the absence infection or a thrombocytopenic syndrome. RESULTS: Of our original 47 study cases,45 cases had sufficient hematologic data for evaluation. Using the aforementioned hematologic injury criteria in our study population,hematologic injury occurred in 4/45 (8.9%) of these acutely asphyxiated neonates. CONCLUSION: When applied to neonates with well-defined acute birth asphyxia, the presence of hematologic injury using these criteria is minimal.
High-Power Microwave Photodiodes

The talk reviews modified uni-traveling carrier photodiodes that are capable of delivering high RF output power levels of >1 Watt. Discrete photodiodes, balanced detectors, photodiode arrays, and waveguide photodiodes are discussed.
Sleep scheduling and lifetime maximization in sensor networks: fundamental limits and optimal solutions

Energy efficiency is a very critical consideration in the design of low cost sensor networks, which typically have fairly low node battery life. This raises the need for providing periodic sleep cycles for the radios in the sensor nodes. Keeping sensors in sleep state also implies that node to sink communication incurs certain delays and there exists a threshold on the duty cycling for the communication delay to be bounded, giving rise to an upperbound on the lifetime of the network i.e., the time until at least one node in the network is able to communicate its sensed data to the sink. This paper aims at establishing tight analytical bounds on the sleeping probabilities of nodes and on the achievable lifetime of wireless sensor networks in a very generic setting. Bounds on the sleeping probability need to be satisfied for proper network functionality. Further, an energy efficient deployment scheme is suggested wherein the battery power depletion is fairly uniformly deployed throughout the network. This scheme makes use of the availability of low power auxiliary channel listening radio. With this scheme, we shown that an improvement in lifetime by a factor of O(/spl radic/n/log n) over uniform distribution of nodes is achievable, where n is the number of nodes in the network. We also show that the throughput capacity of the network is also improved by the same factor. We show also that the maximum lifetime of the network is bounded above by O(n/sup 3/2///spl radic/log n). Further, the accuracy of our analysis is verified by the simulation results presented.
Digitalis and β-blocking agents: Effects on depression following myocardial infarction

Abstract Depression is frequently seen in patients following myocardial infarction (MI), many of whom are receiving digitalis glycosides, β-blockers, or other agents that may exert central nervous system (CNS) effects. In a prospective study of the clinical significance of post-MI depression, 335 patients were assessed using a standardized diagnostic interview for depression at 8 to 10 days, and 190 were reinterviewed at 3 to 4 months. Patients prescribed digitalis, β-blockers, or other cardioactive medications at hospital discharge were identified. Logistic regression analyses were performed to determine the contribution of these agents to depression at 3 to 4 months, controlling for medical and sociodemographic factors as well as for baseline depression. Treatment with digitalis predicted depression at 3 to 4 months ( p p > 0.10). Digitalis may have CNS effects that contribute to depression post-MI and this finding should be considered in the differential diagnosis of depression in cardiac patients.
Increasing Returns, Institutions, and Capital Flows

This paper empirically tests one prominent explanation for why capital has not flowed from the rich to the poor countries: institutions. In contrast to the study by Alfraro, Kalemli-Ozcan, and Volosovych in 2008, institutional quality does not explain the Lucas Paradox. Like them, institutional variables are found to be a very important factor, but in contrast to their findings, initial Gross Domestic Product (GDP) still plays a role in capital flows. In addition, poor countries may have different determinants of capital flows from rich countries. The evidence suggests a threshold income level, where a country receives significantly more capital flows if given a sufficiently high income.
Palladium catalyzed cross-coupling acylation approach to the antitumor antibiotic fredericamycin A

Abstract The palladium catalyzed cross-coupling of the organozinc reagent derived from 2-bromobenzaldehyde ethylene ketal 4 with the acyl chlorides 5 and 8 provides an expeditious route to the BCD 2 and BDCE 2 ring systems of Fredericamycin A 1 .
Ultra-Long Duration Time-Resolved Spectroscopy with Enhanced Temporal Resolution of High-Q Nano- Optomechanical Modes using Interleaved Asynchronous Optical Sampling (I-ASOPS)

Transient responses of high-Q nano-optomechanical modes are characterized with Interleaved-ASOPS, where pump-induced transients are interrogated with multiple probe pulses. Temporal resolution increases linearly with probe-pulse-number beyond conventional ASOPS, achieving sub-ps resolution over μs durations.
Gifting Mecca: Importing Spiritual Capital to West Africa

This discussion of pilgrimage and its gifts, based on ethnographic research in the historically‐rich and deeply Islamic West African city of Kankan, Guinea, concerns the processes of movement of people from this remote region to and from Mecca and the transformative relationship dynamics that surround pilgrims and their families following the hajj. The ‘centre’ in this case study is created, reproduced and reconfigured through the economic processes of personal experiential access and the ability to gift a reminder of that experiential access. Access to the centre transforms religious and cultural perceptions of personhood and comprises a kind of spiritual capital that is transferable. In gerontocratic, patrilineal extended family households of Kankan, participation in pilgrimage creates a new kind of globally implicated person and also may influence the relative status of other members of the household. Relying on two case studies, this paper also highlights potential tensions between two global systems,...
Information technology and organizational learning: a review and assessment of research

Abstract This paper reviews and assesses the emerging research literature on information technology and organizational learning. After discussing issues of meaning and measurement, we identify and assess two main streams of research: studies that apply organizational learning concepts to the process of implementing and using information technology in organizations; and studies concerned with the design of information technology applications to support organizational learning. From the former stream of research, we conclude that experience plays an important, yet indeterminate role in implementation success; learning is accomplished through both formal training and participation in practice; organizational knowledge barriers may be overcome by learning from other organizations; and that learning new technologies is a dynamic process characterized by relatively narrow windows of opportunity. From the latter stream, we conclude that conceptual designs for organizational memory information systems are a valuable contribution to artifact development; learning is enhanced through systems that support communication and discourse; and that information technologies have the potential to both enable and disable organizational learning. Currently, these two streams flow independently of each other, despite their close conceptual and practical links. We advise that future research on information technology and organizational learning proceeds in a more integrated fashion, recognizes the situated nature of organizational learning, focuses on distributed organizational memory, demonstrates the effectiveness of artifacts in practice, and looks for relevant research findings in related fields.
Overall survival in erythrodermic cutaneous T-cell lymphoma: an analysis of prognostic factors in a cohort of patients with erythrodermic cutaneous T-cell lymphoma.

Background The most common cutaneous T-cell lymphomas (CTCLs) are mycosis fungoides and Sezary syndrome. Aim To determine whether blood stage and other prognostic variables affect overall survival (OS) in CTCL. Methods We studied retrospectively 1197 CTCL patients seen at the M.D. Anderson Cancer Center since 1987. Results We identified 124 (10.3%) patients with erythrodermic CTCL (E-CTCL), 63% of whom had positive gene rearrangements in skin and 19 of whom had no evidence of hematologic involvement. The median age at diagnosis was 63 years (range, 26–90 years); the male to female ratio was 1.3 : 1. OS curves were estimated by the Kaplan–Meier method and compared using log-rank tests. The median OS in all 124 E-CTCL patients was 5.1 years (range, 0.4–18.6 years) regardless of the cause of death or blood involvement. Patients were stratified by the H0–H4 staging system with manual or flow cytometric determination of Sezary cell counts (Russell-Jones R, Whittaker SJ. Sezary syndrome: diagnostic criteria and therapeutic options. Semin Cutan Med Surg 2000; 19: 100–108). The median OS was 7.6 years for H0–H2 (< 1000 Sezary cells/L) (n = 23), 5.4 years for H3 (≥ 1000 to ≤ 10,000 Sezary cells/L) (n = 79), and 2.4 years for H4 (≥ 10,000 Sezary cells/L) (n = 22) (P = 0.011). Treatment with systemic steroids, age, serum lactate dehydrogenase, and white blood cell count ≥ 20,000 µL were significant prognostic factors, but large cell transformation, T-cell receptor gene rearrangement, tumor–node–metastasis stage, treatments, and CD4 : CD8 ratio were not. In multivariate analysis, advanced age and elevated lactate dehydrogenase were the strongest predictors of a poor prognosis. Conclusions Serum LDH and age were the strongest predictive factors for OS in E-CTCL.
Forecasting “friends forever”: A longitudinal investigation of sustained closeness between best friends

Using data collected across 19 years, the chief goal of this study was to discover predictors of continued relational closeness between best friends. Participants were same-sex and cross-sex best friend pairs recruited from a small Midwestern college. In 1983, participants completed several tests and activities designed to assess facets of intimacy, with follow-up studies in 1987 and 2002 measuring relational closeness. Regression analysis indicates that both manifest similarity and months of closeness in 1983 are associated with relational closeness in 2002. These results suggest that the investment of resources in the friendship and similarity between friends facilitate friendship longevity and that Kelley et al.’s (1983) conceptualization of closeness as related to interdependence is empirically robust.
Anesthetic Management of a Delayed Carinal Resection Following Traumatic Disruption

Resecting and reconstructing the carina is an anesthetic challenge in the best of circumstances. The surgery is meticulous and requires access to the trachea and bronchi, ruling out traditional lung isolation techniques. When resection of the carina is due to traumatic disruption, confounding thoracic injuries can make adequate ventilation and oxygenation difficult, especially when only one lung is available for ventilation. ECMO is an intervention that provides sufficient oxygenation and an unimpeded surgical field. ECMO also allows use of smaller airway management tools that can be used to ventilate the dependent lung, thus preventing atelectasis and producing better postoperative outcomes.
Coronary Artery Stenosis Following Aortic Valve Replacement and Intermittent Intracoronary Cardioplegia

Abstract From July, 1977, to July, 1980, intermittent cold blood potassium cardioplegia was used in 208 patients undergoing aortic valve replacement. Aortic root injection of the cardioplegic solution at 10°C was followed every 20 to 30 minutes by infusions of the solution through Silastic cannulas sutured in the coronary orifices or reinserted with each injection. Symptoms of myocardial ischemia developed in 6 patients 3 to 30 months postoperatively. Coronary angiography confirmed new stenoses of the left orifice (3 patients), left main trunk (1 patient), left anterior descending coronary artery (2 patients), circumflex coronary artery (1 patient), and right orifice (3 patients). Four patients underwent saphenous vein grafting procedures, with 2 deaths; 2 patients refused reoperation. A seventh patient with 80% stenosis of the circumflex coronary artery and a posterolateral myocardial infarction died 2 months after double-valve replacement. Intermittent cold blood potassium cardioplegia instead of continuous perfusion did not prevent coronary arterial injury. Injuries occurred in the distal coronary arteries as well as the orifices and were not prevented by withdrawal of the cannulas between injections. Tight-fitting cannulas and high-pressure injection should be avoided. A careful search for coronary arterial injury should be made in all symptomatic patients following aortic valve replacement.
Dynamics of superfluid films

A theory of the dynamical properties of a helium film near its superfluid transition is presented. Details are given of previously published results on the linear response of the film to a substrate oscillation. A key role is played by the diffusive motion of quantized vortices, which become free above the thermodynamic Kosterlitz-Thouless temperature ${T}_{c}$ but which only exist as bound pairs below ${T}_{c}$. An analogy with a two-dimensional plasma is presented and used. Contact is made with experiments involving oscillating substrates. The nucleation of single vortices from pairs is calculated, and this process is balanced against pair recombination to calculate the rate of decay of superflow below ${T}_{c}$. Formulas are worked out for the propagation and damping of third sound, and a discussion is given of hydrodynamic modes. An analogy between the dynamical equations for the film and Maxwell's equations is exploited.
U.S. and Indian Spacecrafts Orbit Mars

Mars received two new visitors in September. First, NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft entered into orbit around the planet on 21 September. Just 3 days later, the Indian Space Research Organization's (ISRO) Mars Orbiter spacecraft—known as Mangalyaan—also successfully entered into Mars orbit. Each received a “welcome to the neighborhood” tweet from NASA's Mars rover Curiosity team and the European Space Agency's (ESA) Mars Express team.
Heuristic acceleration of routing in transportation simulations using GPUs

We present a brief overview of how path computations for real-world road network graphs can be accelerated using GPUs, in the context of a large scale transportation simulator. This is motivated by the following observations: (i) Routing is the most computationally intensive part of a large scale transportation simulator, and thus, optimizations to routing that exploit any inherent structure and parallelism in the problem significantly improve application performance; (ii) near-optimal paths are often acceptable in lieu of the most optimal path, which motivates the use of heuristics in speeding up path computations; and finally, (iii) paths from source to destination in real-world road network graphs are spatially constrained, implying that to solve the path problem, one needs to consider only a small subset of the routing graph. This has important practical implications for a GPU, which, while offering a great degree of parallelism, is also significantly constrained by memory limitations. GPUs have already been shown to significantly outperform CPUs in path computation problems for small graphs. The previous observations allow us to deploy GPUs for much larger graphs that arise in transportation simulations.
Thrombin receptor antagonists for the treatment of atherothrombosis: therapeutic potential of vorapaxar and E-5555.

Platelet activation, achieved through a variety of surface receptors and biochemical mediators, represents a key event in the pathogenesis of atherothrombosis and its clinical manifestations. The major pathways involved in platelet activation are triggered by thromboxane A2, adenosine diphosphate and thrombin, with the latter being the most potent of these agonists. Despite the effective inhibition of the first two pathways with aspirin and several generations of P2Y12 receptor antagonists, respectively, the recurrence of ischaemic events in patients with atherothrombosis remains high. In addition, there is a growing concern over the safety profile of increasingly powerful antiplatelet drugs in terms of bleeding, which has tempered expectations of newly developed compounds. Thrombin receptor antagonists are a novel class of antiplatelet agents that inhibit thrombin-mediated platelet activation. Preliminary data indicate that these compounds may have the potential to improve ischaemic outcomes without significantly increasing the bleeding liability. Currently, two agents of this class are under clinical development: vorapaxar (previously known as SCH 530348) and E-5555. In this review we discuss this novel class of antiplatelet agents, focusing in particular on their therapeutic potential.
De novo amino acid biosynthesis contributes to salmonella enterica growth in Alfalfa seedling exudates.

ABSTRACT Salmonella enterica is a member of the plant microbiome. Growth of S. enterica in sprouting-seed exudates is rapid; however, the active metabolic networks essential in this environment are unknown. To examine the metabolic requirements of S. enterica during growth in sprouting-seed exudates, we inoculated alfalfa seeds and identified 305 S. enterica proteins extracted 24 h postinoculation from planktonic cells. Over half the proteins had known metabolic functions, and they are involved in over one-quarter of the known metabolic reactions. Ion and metabolite transport accounted for the majority of detected reactions. Proteins involved in amino acid transport and metabolism were highly represented, suggesting that amino acid metabolic networks may be important for S. enterica growth in association with roots. Amino acid auxotroph growth phenotypes agreed with the proteomic data; auxotrophs in amino acid-biosynthetic pathways that were detected in our screen developed growth defects by 48 h. When the perceived sufficiency of each amino acid was expressed as a ratio of the calculated biomass requirement to the available concentration and compared to growth of each amino acid auxotroph, a correlation between nutrient availability and bacterial growth was found. Furthermore, glutamate transport acted as a fitness factor during S. enterica growth in association with roots. Collectively, these data suggest that S. enterica metabolism is robust in the germinating-alfalfa environment; that single-amino-acid metabolic pathways are important but not essential; and that targeting central metabolic networks, rather than dedicated pathways, may be necessary to achieve dramatic impacts on bacterial growth.
Regional cerebral blood flow alterations in obstructive sleep apnea

Obstructive sleep apnea (OSA) is a condition characterized by upper airway muscle atonia with continued diaphragmatic efforts, resulting in repeated airway obstructions, periods of intermittent hypoxia, large thoracic pressure changes, and substantial shifts in arterial pressure with breathing cessation and resumption. The hypoxic exposure and hemodynamic changes likely induce the structural and functional deficits found in multiple brain areas, as shown by magnetic resonance imaging (MRI) procedures. Altered cerebral blood flow (CBF) may contribute to these localized deficits; thus, we examined regional CBF, using arterial spin labeling procedures, in 11 OSA (age, 49.1±12.2 years; 7 male) and 16 control subjects (42.3±10.2 years; 6 male) with a 3.0-Tesla MRI scanner. CBF maps were calculated, normalized to a common space, and regional CBF values across the brain quantified. Lowered CBF values emerged near multiple bilateral brain sites in OSA, including the corticospinal tracts, superior cerebellar peduncles, and pontocerebellar fibers. Lateralized, decreased CBF appeared near the left inferior cerebellar peduncles, left tapetum, left dorsal fornix/stria terminalis, right medial lemniscus, right red nucleus, right midbrain, and midline pons. Regional CBF values in OSA are significantly reduced in major sensory and motor fiber systems and motor regulatory sites, especially in structures mediating motor coordination; those reductions are often lateralized. The asymmetric CBF declines in motor regulatory areas may contribute to loss of coordination between upper airway and diaphragmatic musculature, and lead to further damage in the syndrome.
Wideband non-coherent MIMO capacity

We consider a multiple-input, multiple-output (MIMO) wideband Rayleigh block fading channel, where the channel state is unknown to both the transmitter and the receiver. With only an average power constraint, we compute the capacity of this channel and consider its interaction with the coherence length, number of transmit and receive antennas and receive signal-to-noise ratio (SNR) per degree of freedom. We establish how large the coherence length has to be in order for the non-coherent channel to have a "near coherent" performance in the wideband regime. More specifically, we show that if the coherence length of the channel is above a certain SNR (bandwidth) dependent threshold, the non-coherent and coherent capacities are the same in the large bandwidth regime. We also propose a signaling scheme that is near-optimal in the wideband regime
Using fast matrix multiplication to find basic solutions

Abstract We consider the problem of finding a basic solution to a system of linear constraints (in standard form) given a non-basic solution to the system. We show that the known arithmetic complexity bounds for this problem admit considerable improvement. Our technique, which is similar in spirit to that used by Vaidya to find the best complexity bounds for linear programming, is based on reducing much of the computation involved to matrix multiplication. Consequently, our complexity bounds in their most general form are a function of the complexity of matrix multiplication. Using the best known algorithm for matrix multiplication, we achieve a running time of O(m1.594 n) arithmetic operations for an m × n problem in standard form. Previously, the best bound was O(m2 n) arithmetic operations.
On a viscoplastic model for rocks with mechanism-dependent characteristic times

This paper summarizes the results of a theoretical and experimental program at Sandia National Laboratories aimed at identifying and modeling key physical features of rocks and rock-like materials at the laboratory scale over a broad range of strain rates. The mathematical development of a constitutive model is discussed and model predictions versus experimental data are given for a suite of laboratory tests. Concurrent pore collapse and cracking at the microscale are seen as competitive micromechanisms that give rise to the well-known macroscale phenomenon of a transition from volumetric compaction to dilatation under quasistatic triaxial compression. For high-rate loading, this competition between pore collapse and microcracking also seems to account for recently identified differences in strain-rate sensitivity between uniaxial-strain “plate slap” data compared to uniaxial-stress Kolsky bar data. A description is given of how this work supports ongoing efforts to develop a predictive capability in simulating deformation and failure of natural geological materials, including those that contain structural features such as joints and other spatial heterogeneities.
The paradox of the hanging string: An explanation using singular perturbations

Abstract The problem of linear transverse oscillations of an elastic perfectly flexible string, hanging freely under its own weight, presents a paradox, in that a solution can be obtained only when the lower end is free. It is shown by using singular perturbations that inclusion of bending stiffness removes the paradox; the solution, however, develops a boundary layer near the lower end to accommodate the boundary conditions. As a result, the behaviour of the solution in the limit as the bending stiffness tends to zero, is singular. Thus, for a string with a simply supported lower end, the natural frequencies asymptotically approach those of the string with a free end, whereas for prescribed motion of the lower end, the thin boundary layer near the lower end effectively alters the amplitude of imposed motion of the string. For actual structures with small bending stiffness, such as risers and drilling strings, this singular behaviour implies the development of large bending stresses near the lower end.
Regional Forcing by Light on Dissolved Oxygen Levels in Shallow Temperate Estuaries

Estuarine oxygen and regional meteorological conditions were studied for 24 Massachusetts estuaries to determine regional influences of light on oxygen dynamics. During July and August 2006, near-bottom dissolved oxygen (DO), temperature, salinity, chlorophyll-a, tide stage, and photosynthetically active radiation (PAR) were measured. Relative low or high DO extrema occurred simultaneously across multiple estuaries despite differences in total oxygen levels. July and August had a total of 19 days with low DO in more than 25 % of sites, including 8 days with low DO in more than 50 % of sites. PAR averaged across nine monitoring locations accounted for a significant fraction of regional DO variance. Correlations between regional DO and regional light were greatest for a 1-day lag in light. Low DO occurred more frequently during low light conditions (PAR 400 μE m−2 s−1). Precipitation did not appear to be a direct driver of DO during this timeframe. Comparison of chlorophyll-a with DO showed a negative correlation, indicating that respiration outpaced photosynthesis. These results suggest that local factors create the potential for hypoxia, but that regional light levels provide a key trigger.
Tuck in Your Shirt, You Squid: Suggestions in ESL*

A discourse completion questionnaire consisting of 60 situations designed to elicit suggestions in English was administered to 28 native speakers of Chinese or Malay and 12 native speakers of American English. The purpose of the study was to determine what, if any, differences exist between the way adult native speakers and nonnative speakers make suggestions and what implications there may be, if any, for the ESL classroom teacher in helping students develop pragmatic competence. Situations reflected three degrees of embarrassment to addressees who were varied by familiarity and sex. Speakers provided suggestions to about 50% of the situations, natives slightly more frequently than did nonnatives; however, nonnatives were slightly more direct in their responses than were natives. All subjects provided suggestions more frequently in urgent situations and less frequently in embarrassing situations. Simple statements of fact were the most common and neutral type of suggestions made by all speakers. Although suggestions made by native and nonnative speakers were basically similar in directness and frequency, they differed in the number and type of politeness strategies used. Examples of successful strategies used by native speakers, which could be taught to ESL students using a functional approach, as well as some of the pragmatically less successful strategies used by nonnative speakers are discussed.
Music box: composing and performing visual music

Music Box is an artistic implementation of emergent behavior and its use to create music. Music Box employs Craig Reynold's flocking algorithm to display animated notes that rise from a written score, then move to create a distinctive flock-lead musical arrangement. The result is emergent sound; a musical arrangement directed by the visual representation of flocking.The goal of this creative exploration is to free the musical score from the prevalent model of composer, performer and listener supported by standard models. Instead the experience is more democratic. Here the composer suggests, the performer follows a few loose rules, and the listener plays with the composition.This is accomplished through the development of artificial intelligence software that applies the visual rules of flocking behaviors to the algorithmic arrangement of musical pitches. Importantly, these visual rules are manipulated by the software user resulting in a dual performance and composition. The result is musical authoring based on the user model of computer video games.
Early stage formation of iron oxyhydroxides during neutralization of simulated acid mine drainage solutions.

The phases and stability of ferric iron products formed early during neutralization of acid mine drainage waters remain largely unknown. In this work, we used in situ and time-resolved quick-scanning X-ray absorption spectroscopy and X-ray diffraction to study products formed between 4 min and 1 h after ferric iron sulfate solutions were partially neutralized by addition of NaHCO3 ([HCO3–]/[Fe3+] < 3). When [HCO3–]/[Fe3+] = 0.5 and 0.6 (initial pH ∼ 2.1 and 2.2, respectively), the only large species formed were sulfate-complexed ferrihydrite-like molecular clusters that were stable throughout the duration of the experiment. When [HCO3–]/[Fe3+] = 1 (initial pH ∼ 2.5), ferrihydrite-like molecular clusters formed initially, but most later converted to schwertmannite. In contrast, when [HCO3–]/[Fe3+] = 2 (initial pH ∼ 2.7), schwertmannite and larger ferrihydrite particles formed immediately upon neutralization. However, the ferrihydrite particles subsequently converted to schwertmannite. The schwertmannite pa...
Human β2-adrenergic receptor polymorphisms: No association with essential hypertension in black or white Americans

Background and Objectives The most common polymorphisms of the human β2-adrenergic receptor-Arg16Gly and Gln27Glu-are associated with alterations in β2-adrenergic receptor responses, both in vitro and in vivo. β2-Adrenergic receptor–mediated vascular responses are affected by ethnicity, blood pressure, and genotype. We tested the hypothesis that these two common β2-adrenergic receptor genetic variants are associated with essential hypertension in black or white Americans. Subjects and Methods In a population-based case-control association study, the relationship between β2-adrenergic receptor genotypes and hypertension was examined in 307 normotensive subjects (128 black and 179 white) and 356 hypertensive subjects (155 black and 201 white). A polymerase chain reaction–based single-stranded conformational polymorphism method with direct sequencing of the bands of interest was used to detect the two frequently occurring β2-adrenergic receptor variants (Arg16Gly, Gln27Glu). Results No significant differences in the distributions of alleles and genotypes of the tested β2-adrenergic receptor variants were found between normotensive and hypertensive groups from either black or white Americans (all P > .05). There was a marked interethnic difference in the frequency of the Gln27Glu β2-adrenergic receptor polymorphism in both normotensive and hypertensive subjects. In normotensive white subjects, the variant Glu27 allele (35.2% versus 18.0%; P < .0001) and Glu27 homozygous genotype (14.0% versus 4.7%; P < .01) were more common than in black subjects. Similarly, in hypertensive white subjects, the variant Glu27 allele (35.8% versus 18.4%; P < .0001) and the Glu27 homozygous genotype (15.9% versus 2.6%; P < .0001) were more common than in black subjects. Conclusions These data suggest that although there are marked ethnic differences in their distribution, the common genetic polymorphisms of the human β2-adrenergic receptor gene do not cosegregate with the presence of hypertension in either black or white Americans. Clinical Pharmacology & Therapeutics (2000) 67, 670–675; doi: 10.1067/mcp.2000.106293
Stochastic Dilemma Hazard Model at High-Speed Signalized Intersections

Dilemma zone (DZ) is an area where drivers can neither stop comfortably nor cross safely when they are presented with a yellow indication at an intersection. The DZ problem is a leading cause for crashes at high-speed signalized intersections. Researchers traditionally assume that vehicles in DZ are equally hazardous and therefore they use the number of vehicles in DZ as an indicator of safety. There is, however, a general understanding among researchers that a DZ-associated accident potential (dilemma hazard thereafter) will vary depending on the subject vehicle's position and speed at the yellow onset. Based on the previous studies on drivers' response to the yellow onset, vehicle kinematics, and a Monte Carlo simulation framework, we present a dilemma hazard model for vehicles in the DZ. In light of this model, each vehicle in DZ is assigned a hazard weight according to its position and speed when the yellow is presented. The proposed model is calibrated and validated using the vehicle trajectory data collected at a high-speed signalized intersection in Christiansburg, Va. Finally, the dilemma hazard model is used to obtain optimal clearance interval for the study site.
Effects of nerve growth factor administration on N-ethyl-N-nitrosourea carcinogenesis

Abstract We attempted to determine whether the sympathetic nervous system in rodents is susceptible to co-carcinogenesis, employing murine salivary nerve growth factor (NGF) as a co-carcinogenic agent. NGF had no co-carcinogenic effect with either methylcholanthrene or ethylnitrosuorea (ENU) on the sympathetic nervous system of the mouse, whether administered transplacentally, postnatally, or both transplacentally and postnatally. At a dose of ENU of 30 μg/g body weight, NGF did not shorten the latent period for tumor induction of BD-IX rats. In contrast, a 25% reduction in latent period was brought about by NGF for tumor appearance in BD-IX rats receiving 90 μg/g ENU. In both cases the frequency of urogenital tumors in rats was increased as a result of NGF administration, at the apparent expense of neural tumors.
3D reconstruction of objects using stereo imaging

Abstract This paper describes two stereo imaging experimental set-ups useful in measuring the 3 D geometry of objects: a parallel optical-axis model and a converging optical-axis model. Digital image correlation is used to find the disparities between corresponding points in a pair of images, for each of these models, with subpixel accuracy. To show the application of the developed algorithms and the stereo imaging experimental set-ups, four different body geometries are used. For some of the objects tested a higher measuring accuracy is obtainable from the converging optical-axis experimental set-up.
Coordinate regulation of mRNAs from multiple calmodulin genes during myoblast differentiation in vitro.

Multiple genes encoding identical calmodulin molecules have been found in all mammalian species so far examined, but little is known regarding the factors involved in regulating the expression of this gene family. We have investigated the possibility of differential regulation under conditions of cell cycle withdrawal and differentiation in the nonfusing BC3H1 myoblast. Transcripts from the three genes are expressed in myoblasts and myocytes and each of the mRNA species decreases during BC3H1 differentiation. Calmodulin protein levels also decrease, although with distinct kinetics with respect to the mRNAs. Previous studies indicated that a decrease in transcription is involved (Epstein et al., Molecular Endocrinology 3:193–202, 1989). In this study, an increase in stability for each of the mRNA species is also shown to contribute to overall mRNA levels. The calmodulin mRNAs are also found to decrease under conditions of cell cycle withdrawal when differentiation is blocked. This demonstrates that the expression of mRNA from all three genes is directly coupled with the proliferation state but only indirectly with the differentiation state. Consistent with this, calmodulin expression decreases in serum deprived fibroblasts as they exit the cell cycle. © 1993 Wiley-Liss, Inc.