cssi/SciSciGPT-SciSciNet huggingface dataset:
Pulse amplification in semiconductor optical amplifiers with ultrafast gain-recovery times

This paper presents detailed numerical and experimental study of SPM in semiconductor optical amplifiers (SOAs) with ultrafast gain-recovery times. These SOAs have a range of gain-recovery speed which is a function of drive current. At increased drive current, the amount of internal ASE in the SOA increases, which causes the small signal gain to saturate and reduces the gain-recovery time. Understanding pulse amplification in these SOAs is important for optimizing the performance of SOA-based optical regenerators and wavelength converters. Our study addresses the full range of gain-recovery times in commercial SOAs extending from less than 10 ps to >100 ps.
Mercury accumulation by largemouth bass ( Micropterus salmoides ) in recently impounded reservoirs

Mercury levels of largemouth bass from three reservoirs in the southeastern United States were highest in the younger, relatively oligotrophic reservoirs and were significantly lower in an older, more eutrophic reservoir in the same drainage system. The reservoir with the highest mercury levels in bass is the reservoir farthest upstream, and is not subject to inputs of municipal or industral wastes. The source of mercury in these reservoirs appears to be the soil which formed theri original sediments. Preliminary data indicate that mercury levels in largemouth bass in these systems decline as the reservoirs age. televated mercury levels in fish appear to be a transitory phenomenon in newly impounded, relatively oligotrophic reservoirs.
Scuffing resistance after tribosynthesis of a modified surface layer

Abstract In this work, the surface layers of steel samples have been modified by a tribological scuffing process to improve the resistance of the surface to subsequent scuffing failure. In general, scuffing is known to involve large plastic strains and high local temperatures. The scuffed surface layers cool rapidly as heat is transported into the bulk material. This deformation and thermal treatment form highly work-hardened surface layers with small grain size. Resistance to scuffing failure typically improves with increasing hardness; for this reason, we have assessed the scuffing resistance of previously scuffed material as follows. We have modified a high-frequency reciprocating rig tribological tester so that a flat sample can be moved in a direction perpendicular to the direction of reciprocation during a ball-on-flat scuffing test. After initiation of scuffing, each flat was moved at a constant velocity, propagating the scuffing effect sideways from the reciprocating line in order to affect an area. After cleaning, the resistance of such areas to scuffing was measured in a second test. Flats of hardened 440C stainless steel were tested. Contrary to expectations, the resistance of tribosynthesized surface layers to subsequent scuffing was significantly degraded compared to as-polished surfaces. In particular, failures in the “run-in” portion of the test, before the load was fully applied, were more common when testing tribosynthesized surface layers. The most likely cause was the significantly increased roughness of the modified surface.
The leveling of coating defects with shear thinning rheology

A one-dimensional model is proposed to predict the leveling of coating defects or irregularities on a planar surface. Though shear thinning rheology is the focus of this paper, any viscous non-Newtonian rheology can be included in the model. Surface tension, gravity and viscous forces are accounted for in the model. A novel numerical technique is presented to obtain solutions of the model. Results agree with a full two-dimensional solution of the flow field obtained with a spectral element method. A new dimensionless group is identified which indicates the significance of shear-thinning rheology. Defects are made with a notched blade used to coat pigmented liquids on polymer films. The defect shapes are obtained at different times by drying under infrared. The dried surface is characterized with a stylus profilometer. The surface profiles and the final amount of leveling compare well with the model predictions.
A universal thermal equation-of-state

Abstract Evidence has steadily accumulated to show that at high temperatures (above the Debye temperature, θ) the thermal pressure, PTH, of solids, is linear with T to a close approximation. This empirical finding yields a simple relationship between P, V, and T quite useful for the computation of the equation-of-state (EOS). For geophysical applications, the empirical data is, so far, limited to a few minerals, all of which are important to our geophysical models of the Earth. The same results have been found for a variety of types of solids, including alkali metals, noble gas solids, alkali halides and metals in addition to minerals. It is argued that the linearity between PTH and T is a general high-temperature property of solids. This includes minerals. Thus it is proposed that there exists a common thermal EOS which transcends the chemical bonding type and crystallographic class.
Reverse-selective membranes formed by dendrimers on mesoporous ceramic supports

Here we report the synthesis and testing of composite membranes that exhibit high reverse selectivities in the removal of a small hydrocarbon species (propane) from a light gas (nitrogen), which is a prototypical separation for such technologies. The high selectivity is a consequence of designing organic moieties that increase the solubility of the heavy component, here propane, while using a mesoporous ceramic scaffold to maintain a high free volume. We also show, through careful control measurements, that some of the variability observed in the membrane performance can be attributed to a small amount of strongly bound solvent from the synthesis/dendrimer processing. This leads to very high selectivities, and results are presented that indicate the stability of the solvent on the membranes.
Total pressure method for vapor‐liquid equilibria at low absolute pressures: Aniline‐nitrobenzene systems

Binary vapor-liquid equilibrium data for use in the successful design and operation of mass transfer equipment at pressures down to approximately 5 mm. Hg may be advantageously obtained by the method of total pressures. In this method the desired equilibrium data are derived from pressure vs. temperature measurements on a convnient number of made-up solutions covering the entire composition range. With a modified Smith and Menzies isoteniscope, it is possible to measure accurately the data required for making the equilibrium calculations down to 2 mm. abs. pressure without the “bumping,” supercooling, and superheating encountered with equilibrium stills. The isoteniscope is simple to construct and operate from 1 atm. to 2 mm. abs. The use of the total pressure method and the isoteniscope is illustrated by the determination of the vapor-liquid equilibrium in the aniline-nitrobenzene system at 5 and 10 mm. abs. In nineteen out of twenty instances the vapor compositions for a given liquid composition are precise to within ± 0.9% and the relative volatility, which varied between 2.54 and 1.85 over the composition and temperature ranges, is precise within ± 1.5%.
Circumferential profiles for region-based analysis of dynamic SPECT data

Kinetic parameters (washin, washout) of dynamic SPECT teboroxime data sets may provide a more sensitive measure of coronary artery disease than conventional (T1, MIBI) static myocardial perfusion studies. A time-consuming and subjective step of the data analysis is drawing regions of interest to delineate blood pool and myocardial tissue regions. The time-activity curves for the regions are then used to estimate local kinetic parameters. In this work, the appropriate time-activity curves are found automatically, in a manner similar to that used for calculating circumferential profiles in conventional static cardiac studies. The drawbacks to applying standard static circumferential profile methods are the high noise level and high liver uptake common in dynamic studies. Searching along each ray for maxima to locate the myocardium does not always provide useful information. Here, the authors propose an iterative scheme in which constraints are imposed on the radii searched. The constraints are based on the shape of the time-activity curve of the circumferential profile members and on an assumption that the short axis slices are approximately circular. The constraints eliminate outliers and help to reduce the effects of the noise and the liver activity. Kinetic parameter estimates from the automatically generated regions were comparable to estimates from manually selected regions in canine dynamic teboroxime studies.
Hear, Hear for the Zebrafish

Our senses of hearing and balance rely on the function of specialized receptor neurons called "hair cells." In this issue of Neuron, Grant et al. report a series of elegant zebrafish experiments that reveal a previously unappreciated role for glia in the regulation of hair cell proliferation and differentiation. This work is a beautiful example of how zebrafish are particularly useful model systems for studying hair cell development and function.
Nonhistone chromosomal proteins and histone gene transcription.

Publisher Summary This chapter discusses that throughout the cell cycle of continuously dividing cells, as well as after the stimulation of nondividing cells to proliferate, a complex and interdependent series of biochemical events occur requiring modifications in the expression of information encoded in the genome. Hence, the cell cycle provides an effective model system for studying the regulation of gene readout. For the past several years, the laboratory has been focusing on the cell-cycle, stage-specific regulation of a defined set of genetic sequences—that coding for the histones. The chapter reviews that in continuously dividing cells as well as after stimulation of nondividing cells to proliferate, (1) regulation of histone gene expression resides, at least in part, at the transcriptional level, and (2) a subset of the nonhistone chromosomal proteins associated with the genome during the S-phase of the cell cycle is responsible for activation of histone gene transcription when DNA replication occurs.
The effect of oxygen on the electrical properties of silicon

Abstract Interstitial oxygen present in solution, as detected by the 9 μ absorption band, increases the Hall mobility of electrons in n -type silicon crystals but decreases the Hall mobility of holes in p -type. These results are explained by the lattice strain produced via dissolved interstitial oxygen impurities. Results on samples saturated with oxygen and heat treated to cause precipitation of SiO 2 in the temperature range of 950–1250°C show that the SiO 2 particles decrease the values of Hall mobility compared to the initial values on samples without precipitates. Re-annealing causes the dissolution of the precipitates and recovery nearly to the initial values of the Hall coefficient.
“Our People Are Still Resisting”: Farmworker Community Organizing and the Texas Agricultural System:

Previous research demonstrates that the contemporary industrial agricultural system in the United States is ecologically and socially destructive. In many ways, it exemplifies the capitalist system...
Disulfiram therapy in alcoholism: patient compliance studied with a urine-detection procedure.

SUMMARY A simple urine test to verify disulfiram (Antabuse®) use has been developed. Compliance with disulfiram therapy was determined in 95 consecutive abstinent alcoholic patients in an outpatient clinic. All patients were allegedly taking disulfiram. Twenty percent of them were found not to be using the drug, even though they said they were. Disulfiram is unusual because it is probably the patient's belief that he is taking it that is therapeutic, not the action of the drug. Because of this, it is difficult to incorporate placebo controls and double-blind procedures into studies of disulfiram efficacy. However, with any research design, no conclusions will be valid if based solely on patients' reports of use.
C-Cell Neoplasia in Asymptomatic Carriers of RET Mutation in Extracellular Cysteine-Rich and Intracellular Tyrosine Kinase Domain.

Summary Germline mutations in RET proto-oncogene associated with multiple endocrine neoplasia type 2 (MEN2) may affect codons for the extracellular cysteine-rich (ECR) or the intracellular tyrosine kinase (ITK) domain of the transmembrane receptor tyrosine kinase protein. We compared C-cell pathology in asymptomatic carriers of RET mutation affecting the 2 domains. Twenty-two asymptomatic carriers (median age, 9.5 years), 10 with mutations in the ECR (codons 634, 611, 618, and 620) and 12 with mutations in the ITK domain (codons 804, 790, 891, and 918), underwent total thyroidectomy. C-cell hyperplasia was identified in 16 (73%), was multifocal and/or bilateral in 11, and was associated with medullary thyroid carcinoma (MTC) in 10 thyroids. When comparing the ECR and ITK groups in 21 carriers from MEN2A/familial MTC families, C-cell hyperplasia was more frequent in the former (90% versus 55%), as was multifocality (70% versus 27%) and MTC (60% versus 27%), despite the significantly younger median age in the former group (5 versus 23 years, P = .04). One asymptomatic carrier had de novo codon 918 mutation (MEN2B) and showed bilateral microcarcinoma with lymph node metastasis at presentation and progressive disease on follow-up. In conclusion, asymptomatic carriers of high-risk RET mutations affecting the ECR were significantly younger and frequently showed C-cell neoplasia, multifocality, and MTC when compared with mutations affecting the ITK domain in the MEN2A/familial MTC families. The presence of C-cell disease, its severity, and aggressiveness correlated with the mutated codon and with increasing age.
Preparation of Stable Sensitized Erythrocytes for Detection of Chlamydial Antibodies

Sheep erythrocytes were treated with glutaraldehyde before sensitization for the indirect hemagglutination test to assay chlamydial antibodies. This treatment markedly increased stability during storage.
Somali Jet in the Arabian Sea, El Nino, and India Rainfall

Interannual variations of the Somali Jet in the Arabian Sea during 1988-99 were linked to El Nino and La Nina episodes and to India west coast rainfall.
On the time complexity of conflict-free vehicle routing

In this paper, we study the following problem: given n vehicles and origin-destination pairs in the plane, what is the minimum time needed to transfer each vehicle from its origin to its destination, avoiding conflicts with other vehicles? The environment is free of obstacles, and a conflict occurs when the distance between any two vehicles is smaller than a velocity-dependent safety distance. We derive lower and upper bounds on the time needed to complete the transfer, in the case in which the origin and destination points can be chosen arbitrarily, proving that the transfer takes /spl theta/(/spl radic/nL~) time to complete, where L~ is the average distance between origins and destinations. We also analyze the case in which origin and destination points are generated randomly according to a uniform distribution, and present an algorithm providing a constructive upper bound on the time needed for complete the transfer, proving that in the random case the transfer requires O(/spl radic/(n logn)) time.
Forecasting freight demand

Freight forecasting is an area that appears to have received considerably less attention than it deserves. The literature available describes a range of techniques that have been applied over the years, none of which seems to have worked extremely well. There are no routinely accepted and applied approaches. Even the “gravity model”, which is the closest thing to a standard technique, is used either out of total naivety or complete frustration over the lack of suitable alternatives. One is forced to conclude that quantitative forecasting techniques for freight are not well developed, at least operationally, in comparison to those used for urban transportation planning.
A preliminary study of fading of 100 megacycle FM signals

This paper describes a statistical study of the short-period fading of 100 megacycle FM signals over a mountainous propagation path under typical midday conditions. Signal intensities are found to be essentially Rayleigh distributed, while the fading increments follow a Gaussian distribution. Included are a statistical determination of the speed of fading and an effective wind velocity which may produce the fading, and a comparison of the statistically determined wind velocity with that measured by more conventional means.
White-tailed deer are a biotic filter during community assembly, reducing species and phylogenetic diversity.

Communityassemblyentails afiltering process, where species found in a local communityare those that can pass through environmental (abiotic) and biotic filters and successfully compete. Previous research has demon- strated the ability of white-tailed deer (Odocoileus virginianus) to reduce species diversity and favour browse-tolerant plant communities. In this study, we expand on our previous work by investigating deer as a possible biotic filter alter- ing local plant community assembly. We used replicated 23-year-old deer exclosures to experimentally assess the ef- fects of deer on species diversity (H ' ), richness (SR), phylogenetic community structure and phylogenetic diversity in paired browsed (control) and unbrowsed (exclosed) plots. Additionally, we developed a deer-browsing susceptibility index (DBSI) to assess the vulnerability of local species to deer. Deer browsing caused a 12 % reduction in Hand 17 % reduction in SR, consistent with previous studies. Furthermore, browsing reduced phylogenetic diversity by 63 %, caus- ing significant phylogenetic clustering. Overall, graminoids were the least vulnerable to deer browsing based on DBSI calculations. These findings demonstrate that deer are a significant driver of plant community assembly due to their role as a selective browser, or more generally, as a biotic filter. This study highlights the importance of knowledge about theplant treeof lifeinassessing theeffects ofbioticfilters onplant communities.Applicationofsuch knowledge has considerable potential to advance our understanding of plant community assembly.
Local area unemployment and the demand for inpatient care among veterans affairs enrollees

Prior research examining the relationship between economic conditions and health service demand has focused primarily on outpatient use. This study examines whether local area unemployment, as an indicator of economic conditions, was associated with use of inpatient care, which is theoretically less subject to discretionary use. Using a random sample of 131,603 patients dually enrolled in the Veterans Affairs (VA) Health System and fee-for-service Medicare, we measured VA, Medicare, and total (VA and Medicare) hospitalizations. Overall, local unemployment was not associated with VA, Medicare, or total hospitalization probability. Among low-income veterans exempt from VA copayments, higher local unemployment was moderately associated with a lower probability of hospitalization through Medicare. For veterans subject to VA copayments, higher local unemployment was moderately associated with a higher likelihood of VA hospitalization. These results suggest inpatient use is less sensitive to the economy, although worse economic conditions slightly affected inpatient demand for select veterans.
Interferometry of wave fronts reflected off conical surfaces.

Interferometry of wave fronts reflected off conical surfaces requires new interferometric schemes. The pencil beam interferometer is proposed as a metrology tool for conical as well as for spherical optical surfaces. The instrument employs two narrow pencil beams which scan the optical surface to be measured. An electronic fringe position readout system, which measures the location of the fringes that develop through interference of the pencil beams, provides high accuracy surface information. Metrology on a waxicon indicates a measurement precision of ±6 nm. Due to the differential nature of the instrument, alignment requirements are relatively modest.
AN ECLECTIC APPROACH TO BUILDING NATURAL LANGUAGE INTERFACES

INKA is a natural language interface to facilitate knowledge acquisition during expert system development for electronic instrument trouble-shooting. The expert system design methodology develops a domain definition, called GLIB, in the form of a semantic grammar. This grammar format enables GLIB to be used with the INGLISH interface, which constrains users to create statements within a subset of English. Incremental parsing in INGLISH allows immediate remedial information to be generated if a user deviates from the sublanguage. Sentences are translated into production rules using the methodology of lexical-functional grammar. The system is written in Smalltalk and, in INKA, produces rules for a Prolog inference engine.
The Maintenance of Conservative Physical Laws within Data Assimilation Systems

In many data assimilation applications, adding an error to represent forcing to certain dynamical equations may be physically unrealistic. Four-dimensional variational methods assume either an error in the dynamical equations of motion (weak constraint) or no error (strong constraint). The weak-constraint methodology proposes the errors to represent uncertainties in either forcing of the dynamical equations or parameterizations of dynamics. Dynamical equations that represent conservation of quantities (mass, entropy, momentum, etc.) may be cast in an analytical or control volume flux form containing minimal errors. The largest errors arise in determining the fluxes through control volume surfaces. Application of forcing errors to conservation formulas produces nonphysical results (generation or destruction of mass or other properties), whereas application of corrections to the fluxes that contribute to the conservation formulas maintains the physically realistic conservation property while providing an ability to account for uncertainties in flux parameterizations. The results suggest that advanced assimilation systems must not be liberal in applying errors to conservative equations. Rather systems must carefully consider the points at which the errors exist and account for them correctly. Though careful accounting of error sources is certainly not an entirely new idea, this paper provides a focused examination of the problem and examines one possible solution within the 4D variational framework.
Book review: Artificial Minds By Stan Franklin (MIT Press)

This book is primarily an exposition of theories of mind and of recent attempts to invent artificial minds. It reviews a large body of work in the fields of artificial intelligence (AI), artificial life, cognitive science, and neuroscience. It is also informed by work in philosophy and in biology, especially neuroscience and the study of animal behavior. The author's own view of the nature of mind emerges largely through his assessments of the various theories he presents. He believes that recent research is leading toward a "new paradigm of mind" (p. 421), a viewpoint which will be appraised later in this review. Franklin writes with a clear and pleasant style, and his expository descriptions are aimed at a broad audience. The reader should have some general mathematical and scientific knowledge, including the basic ideas of how computers and programming languages work, but otherwise no special technical background is required. The level of difficulty of the book is a little higher than that of a Scientific American article.
Automatic importation of relational schemas in Pegasus

The paper describes a technique for importing automatically an external relational schema into Pegasus, a heterogeneous, multidatabase system. The Pegasus data model is a functional object model which supports specialization, object-identity, and nested aggregation. The import algorithm generates the definition of a Pegasus schema which captures the semantics of a relational schema containing information about primary keys and referential integrity constraints. The algorithm described can be adapted easily for other semantic and object-oriented data models. >
Performance implications of synchronization support for parallel Fortran programs

Abstract This paper studies the performance implications of architectural synchronization support for automatically parallelized numerical programs. As the basis for this work, we analyze the needs for synchronization in automatically parallelized numerical programs. The needs are due to task scheduling, iteration scheduling, barriers, and data dependence handling. We present synchronization algorithms for efficient execution of programs with nested parallel loops. Next, we identify how various hardware synchronization support can be used to satisfy these software synchronization needs. The synchronization primitives studied are test&set , fetch&add , and exchange-byte operations. In addition to these, synchronization bus implementation of lock/unlock and fetch&add operations are also considered. Finally, we ran experiments to quantify the impact of various architectural support on the performance of a bus-based shared memory multiprocessor running automatically parallelized numerical programs. We found that supporting an atomic fetch&add primitive in shared memory is as effective as supporting lock/unlock operations with a synchronization bus. Both achieve substantial performance improvement over the cases where atomic test&set and exchange-byte operations are supported in shared memory.
Fundamental Ca2+ signaling mechanisms in mouse dendritic cells: CRAC is the major Ca2+ entry pathway

Although Ca(2+)-signaling processes are thought to underlie many dendritic cell (DC) functions, the Ca(2+) entry pathways are unknown. Therefore, we investigated Ca(2+)-signaling in mouse myeloid DC using Ca(2+) imaging and electrophysiological techniques. Neither Ca(2+) currents nor changes in intracellular Ca(2+) were detected following membrane depolarization, ruling out the presence of functional voltage-dependent Ca(2+) channels. ATP, a purinergic receptor ligand, and 1-4 dihydropyridines, previously suggested to activate a plasma membrane Ca(2+) channel in human myeloid DC, both elicited Ca(2+) rises in murine DC. However, in this study these responses were found to be due to mobilization from intracellular stores rather than by Ca(2+) entry. In contrast, Ca(2+) influx was activated by depletion of intracellular Ca(2+) stores with thapsigargin, or inositol trisphosphate. This Ca(2+) influx was enhanced by membrane hyperpolarization, inhibited by SKF 96365, and exhibited a cation permeability similar to the Ca(2+) release-activated Ca(2+) channel (CRAC) found in T lymphocytes. Furthermore, ATP, a putative DC chemotactic and maturation factor, induced a delayed Ca(2+) entry with a voltage dependence similar to CRAC. Moreover, the level of phenotypic DC maturation was correlated with the extracellular Ca(2+) concentration and enhanced by thapsigargin treatment. These results suggest that CRAC is a major pathway for Ca(2+) entry in mouse myeloid DC and support the proposal that CRAC participates in DC maturation and migration.
Inhibition of serine palmitoyltransferase reduces Aβ and tau hyperphosphorylation in a murine model: a safe therapeutic strategy for Alzheimer's disease

The contribution of the autosomal dominant mutations to the etiology of familial Alzheimer’s disease (AD) is well characterized. However, the molecular mechanisms contributing to sporadic AD are less well understood. Increased ceramide levels have been evident in AD patients. We previously reported that increased ceramide levels, regulated by increased serine palmitoyltransferase (SPT), directly mediate amyloid b (Ab) levels. Therefore, we inhibited SPT in an AD mouse model (TgCRND8) through subcutaneous administration of L-cylcoserine. The cortical Ab42 and hyperphosphorylated tau levels were down-regulated with the inhibition of SPT/ceramide. Positive correlations were observed among cortical SPT, ceramide, and Ab42 levels. With no evident toxic effects observed, inhibition of SPT could be a safe therapeutic strategy to ameliorate the AD pathology. We previously observed that miR-137, -181c, -9, and 29a/b post-transcriptionally regulate SPT levels, and the corresponding miRNA levels in the blood sera are potential diagnostic biomarkers for AD. Here, we observe a negative correlation between cortical Ab42 and sera Ab42, and a positive correlation between cortical miRNA levels and sera miRNA levels suggesting their potential as noninvasive diagnostic biomarkers.
Diasporas and democratization in the post-communist world

If diaspora communities are socialized with democratic values in Western societies, they could be expected to be sympathetic to the democratization of their home countries. However, there is a high degree of variation in their behavior. Contrary to the predominant understanding in the literature that diasporas act in exclusively nationalist ways, this article argues that they do engage with the democratization of their home countries. Various challenges to the sovereignty of their homelands explain whether diasporas involve with procedural or liberal aspects of democratization. Drawing evidence from the activities of the Ukrainian, Serbian, Albanian and Armenian diasporas after the end of communism, I argue that unless diasporas are linked to home countries that enjoy both international legal and domestic sovereignty, they will involve only with procedural aspects of democratization. Diasporas filter international pressure to democratize post-communist societies by utilizing democratic procedures to advance unresolved nationalist goals.
The "Transport Specificity Ratio": a structure-function tool to search the protein fold for loci that control transition state stability in membrane transport catalysis.

In establishing structure-function relationships for membrane transport proteins, the interpretation of phenotypic changes can be problematic, owing to uncertainties in protein expression levels, sub-cellular localization, and protein-folding fidelity. A dual-label competitive transport assay called "Transport Specificity Ratio" (TSR) analysis has been developed that is simple to perform, and circumvents the "expression problem," providing a reliable TSR phenotype (a constant) for comparison to other transporters. Using the Escherichia coli GABA (4-aminobutyrate) permease (GabP) as a model carrier, it is demonstrated that the TSR phenotype is largely independent of assay conditions, exhibiting: (i) indifference to the particular substrate concentrations used, (ii) indifference to extreme changes (40-fold) in transporter expression level, and within broad limits (iii) indifference to assay duration. The theoretical underpinnings of TSR analysis predict all of the above observations, supporting that TSR has (i) applicability in the analysis of membrane transport, and (ii) particular utility in the face of incomplete information on protein expression levels and initial reaction rate intervals (e.g., in high-throughput screening situations). The TSR was used to identify gab permease (GabP) variants that exhibit relative changes in catalytic specificity (kcat/Km) for [14C]GABA (4-aminobutyrate) versus [3H]NA (nipecotic acid). The TSR phenotype is an easily measured constant that reflects innate molecular properties of the transition state, and provides a reliable index of the difference in catalytic specificity that a carrier exhibits toward a particular pair of substrates. A change in the TSR phenotype, called a Δ(TSR), represents a specificity shift attributable to underlying changes in the intrinsic substrate binding energy (ΔGb) that translocation catalysts rely upon to decrease activation energy ( ). TSR analysis is therefore a structure-function tool that enables parsimonious scanning for positions in the protein fold that couple to the transition state, creating stability and thereby serving as functional determinants of catalytic power (efficiency, or specificity).
Risk factors associated with pediatric intensive care unit admission and mortality after pediatric stem cell transplant: possible role of renal involvement.

Background Hematopoietic stem-cell transplant (HSCT) is associated with many risk factors for life-threatening complications. Post-transplant critical illness often requires admission to the pediatric intensive care unit (PICU).
A Spectral-Scanning Magnetic Resonance Imaging (MRI) Integrated System

An integrated spectral-scanning magnetic resonance imaging (MRI) technique is implemented in a 0.12 mum SiGe BiCMOS process. This system is designed for small-scale MRI applications with non-uniform and low magnetic fields. The system is capable of generating customized magnetic resonance (MR) excitation signals, and also recovering the MR response using a coherent direct conversion receiver. The operation frequency is tunable from DC to 37 MHz for wide-band MRI and up to 250 MHz for narrow-band MR spectroscopy.
Output Feedback Control Design for Quadrotors in the Presence of Uncertainties

This paper proposes an output feedback control design for quadrotor Unmanned Aerial Vehicles (UAVs) to deal with unmeasured system states, system uncertainties, and external disturbances. Extended High-Gain Observers (EHGOs) are used to estimate the uncertainties and unmeasured system states. Dynamic inversion utilizes the estimates from EHGOs in the second and third fastest time scales in order to deal with input uncertainties and a form of non-affine control inputs. In plant dynamics, rotational dynamics in the fourth fastest time scale, is forced to be faster than translational dynamics in the slowest time scale to overcome the lack of the number of control inputs in this underactuated mechanical system. Using the singular perturbation method, stability of the closed-loop system is conducted. Throughout numerical simulations, the proposed control algorithm is verified.Copyright © 2015 by ASME
Social Responses to Economic Adjustment: The Resurgence of the Nigerian Protest Movement

The Nigerian student movement was in the forefront with respect to protests against Structural Adjustment Programs because it was the most resilient of the social movements operating within the Nigerian polity. While successive governments were able to disorganize and ban the Nigerian Labor Congress (NLC), the Academic Senior Staff Union and other trade unions and professional associations, the ban on NANS was never sufficiently successful. The students saw themselves as beacons of social justice in the Nigerian society, particularly at this time of military dictatorship and a lack of free expression. More importantly they were able to make others believe they were for the masses fighting against tyranny and unfairness; only the ruling elite called them anarchists and saboteurs. However after years of battling the government which at various points was undemocratic the social protest movements within Nigeria seemed to be rather subdued and highly uncoordinated. The January petroleum subsidy protests of 2012 appeared to be the first protests that approached the magnitude of those conducted by students in the 1980s, and that appearance deserves further exploration.
Post-traumatic stress disorder following emergency peripartum hysterectomy

Our objective was to explore if women who experience emergency peripartum hysterectomy (EPH), a type of severe maternal morbidity, are more likely to screen positive for post-traumatic stress disorder (PTSD) compared to women who did not experience EPH. Using a retrospective cohort design, women were sampled through online communities. Participants completed online screens for PTSD. Additionally, women provided sociodemographic, obstetric, psychiatric, and psychosocial information. We conducted bivariate and logistic regression analyses, then Monte Carlo simulation and propensity score matching to calculate the risk of screening positive for PTSD after EPH. 74 exposed women (experienced EPH) and 335 non-exposed women (did not experience EPH) completed the survey. EPH survivors were nearly two times more likely to screen positive for PTSD (aOR: 1.90; 95 % CI: 1.57, 2.30), and nearly 2.5 times more likely to screen positive for PTSD at 6 months postpartum compared to women who were not EPH survivors (aOR: 2.46; 95 % CI: 1.92, 3.16). The association of EPH and PTSD was statistically significant, indicating a need for further research, and the potential need for support services for these women following childbirth.
Effects of chloride channel inhibitors on H2O2-induced renal epithelial cell injury

Oxidative stress contributes to renal epithelial cell injury in certain settings. Chloride influx has also been proposed as an important component of acute renal epithelial cell injury. The present...
An educational tool for understanding the cardiopulmonary changes associated with aging.

Normal aging is associated with cardiac, vascular, and pulmonary adaptations that significantly affect the individual's ability to maintain homeostasis. To understand the changes associated with ag...
"Curing MS: How Science Is Solving the Mysteries of Multiple Sclerosis".

SUMMARY On a grander scale, multiple sclerosis is a battle between a patient's will to fight and the disease's vicious attack on central nerve cells. On a cellular scale, it's between the T helper 1 (Th1) cell, which attacks and destroys the myelin sheath that protects nerve cells, and the Th2 and Th3 cells, which try to bring Th1 cells under control.
Factors Influencing ACT After Intravenous Bolus Administration of 100 IU/kg of Unfractionated Heparin During Cardiac Catheterization in Children:

Anticoagulation using intravenous bolus administration of unfractionated heparin (UFH) aims to prevent thromboembolic complications in children undergoing cardiac catheterization (CC). Optimal UFH dosage is needed to reduce bleeding complications. We analyzed the effect of bolus UFH on activated clotting time (ACT) in children undergoing CC focusing on age-dependent, anesthesia-related, or disease-related influencing factors. This retrospective single-center study of 183 pediatric patients receiving UFH during CC analyzed ACT measured at the end of CC. After bolus administration of 100 IU UFH/kg body weight, ACT values between 105 and 488 seconds were reached. Seventy-two percent were within target level of 160 to 240 seconds. Age-dependent differences were not obtained ( P = .407). The ACT values were lower due to hemodilution (total fluid and crystalloid administration during CC, both P < .001), with premedication of acetylsalicylic acid ( P = .014) and low-molecular-weight heparin ( P = .049). Arterial thrombosis (3.85%), venous thrombosis (0.55%), and bleeding (1.65%) following CC did not correlate with ACT values but occurred more frequently in children between 1 month and 1 year of age (91%). In conclusion, with a bolus of 100 IU UFH/kg, an ACT target level of 160 to 240 seconds can be achieved during CC in children in 72%, which is influenced by hemodilution and anticoagulant and antiplatelet premedication but not by age.
Epidemiology, Virology, and Pathogenesis of the Zika Virus: From Neglected Tropical Disease to a Focal Point of International Attention

Over the past year, the Zika virus, an arthropod-borne Flavivirus, has transitioned from a relatively unknown tropical disease to the cause of a public health emergency. The Zika virus is transmitted by the Aedes species of mosquito as well as by sexual intercourse. Although the symptoms of acute Zika virus infection are usually mild and self-limited, it causes fetal microcephaly in pregnant women, and is associated with an increased risk of Guillain-Barre syndrome. The risk of microcephaly from Zika virus infection is estimated to be highest in women who are infected during the first trimester of pregnancy. The Zika virus has been shown to have significant neurotrophism in vivo and in vitro, although further study is needed to characterize its mechanisms of pathogenesis. Zika virus has previously caused two known outbreaks in the Pacific region prior to the current epidemic in South and Central America, and the current epidemic has affected at least 440,000 to 1,300,000 people. The population of the vector for the current epidemic, Aedes aegypti, varies seasonally in the United States, however there have been few documented cases of local spread of the Zika infection in the United States and it is unclear whether epidemic spread of Zika will occur within the United States.
Characterization of the Contractile 5HT Receptor in the Rat Stomach Fundus

Serotonin is a potent contractile agonist in the rat stomach fundus (ED50 = 3.0 nM). Contraction to serotonin in the fundus was not associated with the indirect release of acetylcholine or cyclooxygenase-derived products. Contraction to serotonin was potently antagonized by calcium channel antagonists, such as nitrendipine and diltiazem, suggesting that extracellular calcium influx is involved in the response. Calcium channel antagonists, however, do not abolish the contractile response to serotonin suggesting that contraction, in part, also results from the utilization of intracellular stores of calcium. With regard to second messenger systems, serotonin did not increase basal levels of either cAMP, cGMP, or increase phosphoinositide turnover. The receptor mediating contraction to serotonin in the rat fundus was characterized with selective serotonergic agonists and antagonists. Our data suggest that the receptor mediating contraction to serotonin in the fundus is not a 5HT-2, 5HT-3, 5HT-1A, 5HT-1B, or high affinity tryptamine binding site as defined with radiolabeled ligands using brain membranes. Based on the use of agonists and antagonists, the serotonin contractile receptor in the rat fundus is similar to, but not identical to, the 5HT-1C receptor. The relationship between the contractile serotonergic receptor in the fundus to the 5HT-1D binding site requires further study.
Endoscopic Treatment of Obesity

Obesity affects a third of the adults in the USA. Current weight-loss therapies include lifestyle therapy, pharmacotherapy, and bariatric surgery. Bariatric surgery is the most effective therapy; however, only 1 % of the patients who qualify are actually treated with bariatric surgery. Moreover, a weight regain in 3–10 years after bariatric surgery occurs in a significant number of patients and has been difficult to treat. New endoscopic procedures and endoscopically placed devices are currently being studied for use in the treatment of obesity. These devices and procedures overcome many of the obstacles preventing patients from undergoing bariatric surgery and provide a safer mechanism for treating weight regain after Roux-en-Y gastric bypass (RYGB). With these new therapies, endoscopists are poised to fill an important gap in the treatment of obese patients. This chapter reviews the role of endoscopy for weight regain after RYGB and in primary bariatric therapy.
Interfacial Li-ion localization in hierarchical carbon anodes

Abstract An understanding of the nanoscale structure and energetics of carbon composites is critical for their applications in electric energy storage. Here, we study the properties of carbon anodes synthesized from low-cost renewable lignin biopolymers for use in energy storage applications such as Li-ion batteries. The anodes possess both nanoscale and mesoscale order, consisting of carbon nanocrystallites distributed within an amorphous carbon matrix. Molecular dynamics simulations of an experimentally validated model of the anode is used to elucidate the nature of Li-ion storage. We report the discovery of a novel mechanism of Li-ion storage, one in which Li+ is not intercalated between layers of carbon (as is the case in graphitic anodes), but rather is localized at the interface of crystalline carbon domains. In particular, the effects of Li-ion binding energy on the Li-Li, Li-H, and Li-C pair distribution functions are revealed, along with the effect on charge distribution. Lastly, the atomic environments surrounding the Li-ions are grouped on the basis of ion energy and then convolved into archetypal structural motifs that reveal deep insight into the geometry of ion localization in disordered systems.
Food Insecurity and Cardiovascular Health in Pregnant Women: Results From the Food for Families Program, Chelsea, Massachusetts, 2013-2015.

Background Food insecurity, uncertainty about the ability to acquire adequate food, is associated with cardiometabolic disease in pregnant women. Whether food insecurity interventions improve cardiometabolic health is unknown. Methods We conducted a retrospective analysis of women who visited the obstetrics clinic in a community health center from 2013 through 2015. Patients could be referred to the Food for Families (Food for Families) program, which connects food insecure women to food resources. We hypothesized that participation in Food for Families would be associated with better blood pressure and blood glucose trends during pregnancy. We used a propensity score-matched design to reduce bias from differential entry into Food for Families. Results Eleven percent of women who visited the obstetrics clinic were referred to Food for Families. In propensity score-matched analyses, we found no difference in baseline systolic blood pressure (SBP) between those who were referred and enrolled in Food for Families (113.5 mm Hg), those who were referred and did not enroll in Food for Families (113.9 mm Hg), and those who were not referred to Food for Families (114 mm Hg) (P = .79). However, during pregnancy, women who were referred to and enrolled in Food for Families had a better SBP trend (0.2015 mm Hg/wk lower, P = .006). SBP trends did not differ between women who were referred and did not enroll in Food for Families and those who were not referred. We observed no differences in blood glucose trends between groups (P = .40). Conclusions Food for Families participation was associated with better blood pressure trends in pregnant women but no differences in blood glucose trends. Food insecurity reduction programs may improve cardiovascular health for vulnerable pregnant women, and this topic deserves further study incorporating randomized program entry.
Infinite Dimensional Mathematical Programming

In this chapter we are concerned with the generalization of finite-dimensional mathematical programming to infinite-dimensional vector spaces. This topic is pertinent to dynamic optimization because dynamic optimization in continuous time de facto occurs in infinite-dimensional spaces since the variable x (t), even if x is a scalar, has an infinity of values for continuous \(t \in \left[t_0, t_f\right] \subseteq \mathfrak{R}^{1}_{+}\) where t f < t 0.
Challenges and Future Developments for Improvement in the Diagnosis and Management of Cushing’s Disease

Cushing’s disease presents a number of new challenges for the future. A number of advances in technology show promise in helping us perform a more accurate evaluation of the physiological effects of this illness. Establishing the diagnosis precisely and without excessive patient discomfort is a major goal. It goes without saying that improved methods of treatment are also desirable. Advances in molecular biology and genetics offer the promise of targets for the treatment of Cushing’s syndrome and Cushing’s disease that may be more effective in achieving a durable remission. Some of these advances are discussed in this chapter.
ALGORITHMS FOR COMPUTATION WITH WHOLE NUMBERS

This chapter discusses algorithms for computation with whole numbers. In the Hindu–Arabic numeration system, each digit in a numeral indicates a particular number of ones, tens, and hundreds; therefore, the fundamental idea of computational algorithms, that use the properties of this numeration system, is to determine in an efficient manner the total number of ones, tens, and hundreds. The modern Roman numeration system employs the subtractive principle. The Hindu–Arabic system employs the positional and additive principles. The chapter describes how the computation algorithms depend on the properties of the Hindu–Arabic numeration system and on the properties of the whole-number system.