cssi/SciSciGPT-SciSciNet huggingface dataset:
On the stability of a class of non-linear continuous systems†

Abstract A procedure to find the existence and domain of asymptotic stability for a class of systems described by a set of non-linear partial differential equations is presented in the context of semigroup theory. No a priori bound is imposed on the non-linearity which is assumed to be a quad ratic (bilinear) or multilinear form. The linearized system can be non-self-adjoint and need not be asymptotically stable equation by equation. The solution of the stability problem is carried out. in two steps : (a) the development of an L2-like norm that bounds above the sup norm, a requirement to obtain a useful estimate of the non-linear term, and (a)the computation of an estimate of the L2-likc norm of the semigroup generated by the linearized system in terms of its usual L2 norm.
X-ray fluorescence as a method of monitoring metal catalyst content during the purification of carbon nanotubes

Abstract There have been several studies that suggest that catalyst metals in carbon nanotubes (CNTs) may pose a health threat. As there are many potential applications of CNTs in medicine, it is important to be able to quantitatively determine the amount of metal catalyst contained in a CNT sample. The relative catalyst content of carbon nanotube samples synthesized via arc-discharge has been determined at various stages of the purification process using X-ray fluorescence (XRF) analysis. Purification was achieved by immersing samples in heated nitric acid. The intensities of the nickel Kα X-rays were studied to determine the relative catalyst content in the samples. Scanning electron microscopy (SEM) images of purified nanotubes have been compared to the images of a sample that has been irradiated by 0–15 keV bremsstrahlung in order to determine if the XRF analysis of the nanotubes is in any way destructive. No obvious structural defects were observed as the result of irradiation.
Alfalfa Weevil: Influence of Apholate on Reproduction in the Laboratory

The most acceptable age for apholate treatment of Hypera postica (Gyllenhal) was as reproductively mature adult; treatment of females only slightly reduced egg viability. Crossing treated weevils of both sexes, or treated males and untreated females, resulted in strongly reduced egg viability. A gradual increase in egg viability became apparent about 3 weeks after treatment. Gross changes in the size of reproductive organs caused by apholate treatment of sexually immature and mature alfalfa weevils were determined. Growth in treated sexually immature female ovaries and oviduets was inhibited for 3–4 weeks, but growth of immature testes was essentially retarded throughout the 5-week test period. Growth of Untreated testes was relatively uniform, whereas growth of untreated ovaries and oviducts occurred primarily toward the end of the test period. The ovaries and testes of sexually mature weevils continued to decrease in size for 5 weeks following treatment. Oviducts decreased in size during the first week, then remained constant. When caged with virgin females, untreated males tended to mate first. Alternate exposure of females to treated and untreated males produced decreasing oscillations in egg viability, tending toward a uniform level near 70%. It appears that apholate-treated male alfalfa weevils may not compete sexually on an equal basis with untreated males.
Factors influencing HIV serodisclosure among men who have sex with men in the US: An examination of online versus offline meeting environments and risk behaviors

One key component in HIV prevention is serostatus disclosure. Until recently, many studies have focused on interpersonal factors and minimally considered meeting venues as they pertain to disclosure. Using data (N = 3,309) from an online survey conducted across 16 U.S. metropolitan statistical areas, we examined whether HIV serodisclosure varies by online/offline meeting venues in both protected and unprotected anal intercourse encounters. Most of the sample (76.9 %) reported meeting men for sex (last 90 days) both online and offline, versus 12.7 % offline only and 10.4 % online only. After controlling for other variables, we found that the men who meet partners in both online and offline were 20~30 % more likely to report disclosing their HIV status prior to sex than men who met their partners exclusively either offline or online. While previous studies have identified the Internet as a risk environment, our findings suggest bi-environmental partner seeking may also have beneficial effects.
Tuber initiation and development in irrigated and non-irrigated potatoes

Tuber initiation and development are processes basic to potato production and are particularly critical in areas with short growing seasons. It is important to know how and to what extent management decisions affect these processes in order to maximize the yield of marketable tubers. A two-year field study, conducted in southcentral Alaska, examined top growth, tuber initiation, and tuber development in eight potato cultivars grown with and without irrigation. Plants of the cultivars Allagash Russet, Bake-King, Green Mountain, Kennebec, Lemhi Russet, Russet Burbank, Shepody, and Superior were harvested weekly throughout the growing season, and top dry weight, numbers of tubers, and individual tuber fresh weights were recorded. Top dry weight was reduced by moisture stress shortly after emergence in 1993, and about one month following emergence in 1994, when early-season soil moisture was greater. The weight of tubers was similarly affected within approximately 5 wk of emergence in 1993 and 6 weeks in 1994. Tuber weight at harvest was increased two-to three-fold by irrigation in all cultivars. The number of tubers each plant set was affected by irrigation in most, but not all, cultivars. Some varieties (Lemhi Russet in 1994, Allagash Russet both years) set more tubers than were maintained through the growing season. Tuber remnants found during sample collection indicated that tuber reabsorption had occurred. Irrigated Green Mountain had more than one tuber initiation period during the season, whereas other varieties such as Shepody maintained a relatively constant number of tubers following initial tuber set. Tuber size distribution at the end of the growing season showed that larger tubers were favored by irrigation.
Sargent versus Simon: Bounded Rationality Unbound

T. J. Sargent called his latest venture Bounded Rationality in Macroeconomics and tried to make connections with H. A. Simon's program of bounded rationality and artificial intelligence. The irony is that rational expectations theory, born from the same mother--Carnegie Mellon University--as bounded rationality, after trying to kill her big sister, then apparently came around to embracing her in the person of Sargent. But was Simon's interpretation of bounded rationality the same as Sargent's? Did Simon and Sargent mean the same by artificial intelligence? Not quite. The different interests of Sargent and Simon resulted in vastly different interpretations of bounded rationality and artificial intelligence. Copyright 1997 by Oxford University Press.
Cooperative production: a comparison of lower and upper bounds

Abstract A group of agents share a one-input one-output convex technology for producing a public or private good. The agents must agree on a level of output to produce and a way to allocate both the output (in the private good case) and the costs of production. The agents would like everyone's utility level to fall between some lower and upper bound. We consider two such bounds: the stand alone bound and the unanimity bound. An agent's stand alone utility level is the utility he would receive if he had free access to the technology by himself. An agent's unanimity utility level is the utility he would receive if everyone else had the same preferences as him and the agents split the output (in the private good case) and the cost of production equally. Normally there is some symmetry in the strength of an upper bound vs. the strength of a lower bound; in some situations the upper bound is more relevant to the allocation problem, while in other situations the lower bound is more relevant. However, we show that the unanimity bound is stronger than the stand alone bound; the unanimity bound always has an impact on the production decision, while the stand alone bound does not.
Distributions for storm surge extremes

The present paper is an attempt to assess a variety of potential probabilistic models for the meteorologically driven storm surge component of a long term water level observation record at Sandy Hook, New Jersey. Simple assumptions are made with regard to the record, and the fitting of the extreme values of the data are assessed graphically in observation space for determining quality of fit in the upper tail of the data. Results are presented which show a comparison of typical distributions utilized along with some distributions not before utilized for coastal storm surge.
Perspectives on Systems Biology Applications in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a microvascular complication of type 1 and 2 diabetes with a devastating impact on individuals with the disease, their families, and society as a whole. DKD is the single most frequent cause of incident chronic kidney disease cases and accounts for over 40 % of the population with end-stage renal disease. Contributing factors for the high prevalence are the increase in obesity and subsequent diabetes combined with an improved long-term survival with diabetes. Environment and genetic variations contribute to DKD susceptibility and progressive loss of kidney function. How the molecular mechanisms of genetic and environmental exposures interact during DKD initiation and progression is the focus of ongoing research efforts. The development of standardized, unbiased high-throughput profiling technologies of human DKD samples opens new avenues in capturing the multiple layers of DKD pathobiology. These techniques routinely interrogate analytes on a genome-wide scale generating comprehensive DKD-associated fingerprints. Linking the molecular fingerprints to deep clinical phenotypes may ultimately elucidate the intricate molecular interplay in a disease stage and subtype-specific manner. This insight will form the basis for accurate prognosis and facilitate targeted therapeutic interventions. In this review, we present ongoing efforts from large-scale data integration translating “-omics” research efforts into improved and individualized health care in DKD.
Micropropulsion using a Nd:YAG microchip laser

Small, lightweight, low power solid state and semiconductor lasers are enabling the development of a new class of thruster systems for micro- and nanosatellites. These devices generate thrust by laser ablation of a solid propellant using on-board lasers and permit small satellites to perform maneuvers such as orbit maintenance, precision pointing, and formation flying. In this work we present a concept for micropropulsion called the microchip laser thruster (MLT) that is based on laser ablation by a passively Q-switched Nd:YAG microchip laser. The microchip laser enables on-board ablation by sub-ns, high peak power, high repetition rate Gaussian pulses. A propellant feed concept is proposed that consists of a cylindrically shaped solid propellant and a single drive motor. Based on measurements of single pulse laser ablation in aluminum, copper and indium targets, we find that aluminum provides the best overall thrust and specific impulse (I sp ). Specifically, for a MLT system employing a 10 μJ/pulse, 10 kHz, 1064 nm microchip laser and Al propellant, we report the following system parameters: thrust range equals 0.5 μN - 5 μN, I sp equals 4900 s, system mass equals 455 g, and maximum required power equals 6.5 W. Atomic force and scanning electron microscope images of craters formed by single and multi-pulse ablation are shown to provide insight into effective propellant feed mechanism designs.
Life cycle energy and greenhouse gas emissions for an ethanol production process based on blue-green algae.

Ethanol can be produced via an intracellular photosynthetic process in cyanobacteria (blue-green algae), excreted through the cell walls, collected from closed photobioreactors as a dilute ethanol-in-water solution, and purified to fuel grade ethanol. This sequence forms the basis for a biofuel production process that is currently being examined for its commercial potential. In this paper, we calculate the life cycle energy and greenhouse gas emissions for three different system scenarios for this proposed ethanol production process, using process simulations and thermodynamic calculations. The energy required for ethanol separation increases rapidly for low initial concentrations of ethanol, and, unlike other biofuel systems, there is little waste biomass available to provide process heat and electricity to offset those energy requirements. The ethanol purification process is a major consumer of energy and a significant contributor to the carbon footprint. With a lead scenario based on a natural-gas-fuel...
Measurement of pulse asymmetry by three-photon-absorption autocorrelation in a GaAsP photodiode.

Three-photon absorption in a GaAsP photodiode is used for what is believed to be the first time for nonlinear optical autocorrelation at wavelengths from 1.4 to 1.6microm . Theoretical intensity dependence and contrast ratios are achieved, and the ratio of the three- to the two-photon-absorption coefficient is measured. Finally, it is demonstrated that pulse asymmetry can be measured with no direction-of-time ambiguity by use of unbalanced three-photon-absorption autocorrelation.
Mobility on the reconstructed Pt(100)-hex surface in ethylene and in its mixture with hydrogen and carbon monoxide

By using high-pressure scanning tunneling microscopy and ambient-pressure X-ray photoelectron spectroscopy, we studied the mobility along with composition, structure and reactivity on the Pt(100)-hex surface. Adsorbates are mobile under 1 Torr of C2H4 and C2H4–H2 mixtures, but adding 3 mTorr of CO quenches the mobility. Ethylene-related adsorbates can also weaken Pt–Pt bonds and thus facilitate displacements in the hexagonal layer.
On the existence of generalized inverse estimators in a singular system of equations

This paper deals with estimation problems in the context of singular systems of equations. It provides the necessary and sufficient conditions for the existence of restricted estimators as a routine extension of the standard theory of restricted least squares estimation. The paper also provides the means for carrying out tests of hypotheses on subsets of restrictions imposed on the system by explicitly providing an expression for the (appropriate) Lagrange multipliers.
Microbiology: Jekyll or hide?

Many bacteria can adopt different lifestyles: in a free-living state, they are virulent and cause disease; in a surface-attached community, they are less virulent but may go unnoticed. How is this ‘decision’ made?
Gonadotropin regulation of in vitro androgen production by reptilian testes.

The hormonal regulation of in vitro androgen production by minced testes from seven species of reptiles, including chelonians, squamates and crocodilians, was studied with the aid of purified FSH and LH from a variety of tetrapod species. Considerable variation in the steroidogenic response was evident depending on both the source of the testis and the source of the hormone, but in general, all reptiles responded to all preparations of both FSH and LH. Some phylogenetic specificity was evident in the response to hormones; e.g., turtles were relatively unresponsive to hormones derived from snakes. The relative potencies of FSH and LH showed some variations between turtles and other reptiles. For example, turtles were relatively insensitive to mammalian (ovine, bovine, rat and human) LH and hCG, whereas snakes and alligators responded similarly to mammalian FSH and LH. However, turtle testes were highly sensitive to LH preparations from many nonmammalian species, especially from the sea turtle. Some synergism between FSH and LH was evident at low doses, but immunological tests supported the conclusion that both gonadotropins have intrinsic activity in regard to the stimulation of steroidogenesis. These results correlate well with recent information on the nature of gonadotropin binding to the reptilian testis. The reptilian testis, like the ovary, differs markedly from the mammalian gonad in the lack of LH specificity for the regulation of steroidogenesis. Comparison with responses in other tetrapods suggests that the reptilian condition does not reflect the “primitive” tetrapod pattern of hormonal regulation.
History of Crystalline Polymers

Abstract The history of crystalline polymers closely parallels the development of polymer science itself. This paper discusses, in historical perspective, the work that led to the recognition that crystalline polymers exist and to the understanding of the structure, morphology, and properties that evolved. A chronological approach is taken and the cornerstones of major discoveries delineated. Initially there was a period where significant physical observations were made but could not be explained because the concept of polymers, no less crystallinity, was unheard of. Early x-ray diffraction work was extremely difficult to interpret for similar reasons. When it was established that polymers existed as bona fide molecular entities, structural analysis using classical diffraction methods soon followed. The principles of crystallization kinetics and the thermodynamics of fusion were firmly established by theory and experiment and found to have the same scientific basis as similar phenomena in low molecular we...
Spatial effects in the detection of γ-aminobutyric acid: Improved sensitivity at high fields using inner volume saturation

The MEGA-PRESS-IVS method has been developed, which combines MEGA (a frequency-selective editing technique) editing with the point-resolved spectroscopy sequence (PRESS) and inner volume saturation (IVS) localization, reducing the deleterious effects of spatial variation in coupling evolution. The IVS method has been previously described for improved efficiency of lactate detection. The current study demonstrates that the combination of MEGA-PRESS with IVS results in increased sensitivity for edited single-voxel measurements of glutamate and gamma-aminobutyric acid (GABA). A four-compartment model of coupling evolution is investigated through simple product operators and full spin-system simulations and the predicted pattern of signal evolution is demonstrated through MEGA-PRESS-MRSI. MEGA-PRESS-IVS is then compared to MEGA-PRESS in a phantom and an average signal increase of 24% is demonstrated in five healthy volunteers.
Parallels: The Soldiers' Knowledge and the Oral History of Contemporary Warfare. By J. T. Hansen, A. Susan Owen, and Michael Patrick Madden. (New York: Aldine de Gruyter, 1992. xii + 250 pp. Cloth, $39.95, ISBN 0-202-30391-8. Paper, $19.95, ISBN 0-202-30392-6.)

Parallels reclaims the experience of American and Soviet participants in the two longest and most devastating episodes of contemporary warfare: Vietnam and Afghanistan. The volume is constructed directly from the narratives and recollection of surviving veterans, and encapsulates the voiced "realities," both choral and discordantly individual, of what those participants have undergone and endured. In their very intensity and authenticity, these voices pose a challenge to conventional understandings of contemporary warfare.
Transfer of Practices and Conceptions of Teaching and Learning Mathematics

This article reveals the findings of a 3-year, qualitative study that began by identifying the pedagogical practices and conceptions of teaching and learning espoused or modeled within a reputable teacher-preparation program. The study examined the transfer of these practices and conceptions into in-service settings. Findings indicated that preservice practices and conceptions carry over into in-service settings; 71% of observed in-service practices were identified as being aligned with those advocated or demonstrated within the preservice program.
A non-linear theory for oscillations in a parallel flow

Three-dimensional periodic oscillations in the shear flow region between two parallel streams are considered up to that second order of the oscillation amplitude. It is shown that, as an integral part of the oscillation, there is a mean secondary flow in the nature of a longitudinal vortex. Despite the dissimilarity in the profile of the basic flows, several of the principal features of the calculated results can be compared with those observed for the Blasius flow by Schubauer and Klebanoff & Tidstrom at the National Bureau of Standards.
Implementing fast JVM interpreters using Java itself

Most Java Virtual Machines (JVMs) are themselves written in unsafe languages, making it unduly difficult to build trustworthy and safe JVM platforms. While some progress has been made on removing compilers from the trusted computing base (using certifying compilation), JVM interpreters continue to be built almost exclusively in C/C++. We have implemented an alternative approach, in which the JVM interpreter itself is built in Java, and runs atop a host JVM execution environment. Despite benefiting from the additional safety guarantees of the JVM runtime system, the execution overhead of our nested Java interpreter is quite acceptable in practice. Our results suggest that implementors should concentrate their efforts on optimizing just-in-time compilers rather than on interpreters. If a mixed-mode VM environment is desired, a generic JVM interpreter can subsequently be created using Java itself.
Research Experience for Veterans and Teachers: Motivation, Program Description, Outcomes and Expectations for Future

Students, especially from the underrepresented groups, are largely underprepared for and unaware of all the STEM opportunities at the undergraduate level. We have recognized this need with two populations: students that come directly out of K-12 schools and military veterans transitioning into college.We offer two programs to combat lower STEM enrollment and attrition at post-secondary institutions: a Research Experience for Teachers program that instructs teachers on an innovative product realization process to excite their K-12 students about STEM disciplines and an Experiential Learning for Veterans in Assistive Technology and Engineering program as a mechanism to advise and prepare Veterans with disabilities for their transition from the combat field to an academic career.In the following paper we look at a novel attempt to combining the two seemingly diverse populations of Teachers and Veterans in a single training initiative, made possible by their overlapping needs and STEM theme.Copyright © 2014 by ASME
UPDATE-ENABLED TRIPLIFICATION OF RELATIONAL DATA INTO VIRTUAL RDF STORES

The current buzzword in the Internet community is the Semantic Web initiative proposed by the W3C to yield a Web that is more flexible and self-adapting. However, for the Semantic Web initiative to become a reality, heterogeneous data sources need to be integrated in order to enable access to them in a homogeneous manner. Since a vast majority of data currently resides in relational databases, integrating relational data sources with semantic web technologies is at the top of the list of activities required to realize the semantic web vision. Several efforts exist that publish relational data as Resource Description Framework (RDF) triples; however almost all current work in this arena is uni-directional, presenting data from an underlying relational database into a corresponding virtual RDF store in a read-only manner. An enhancement over previous relational-to-RDF bridging work in the form of bi-directionality support is presented in this paper. The bi-directional bridge proposed here allows RDF data updates specified as triples to be propagated back into the underlying relational database as tuples. Towards this end, we present various algorithms to translate the triples to be updated/inserted/deleted into equivalent relational attributes/tuples whenever possible. Particular emphasis is laid, in this paper, on the translation and update propagation process for triples containing blank nodes and reification nodes, and a platform enhanced with our algorithms, called D2RQ++, through which bi-directional translation can be achieved, is presented.
GADEM: a genetic algorithm guided formation of spaced dyads coupled with an EM algorithm for motif discovery.

Genome-wide analyses of protein binding sites generate large amounts of data; a ChIP dataset might contain 10,000 sites. Unbiased motif discovery in such datasets is not generally feasible using current methods that employ probabilistic models. We propose an efficient method, gadem, which combines spaced dyads and an expectation-maximization (EM) algorithm. Candidate words (four to six nucleotides) for constructing spaced dyads are prioritized by their degree of overrepresentation in the input sequence data. Spaced dyads are converted into starting position weight matrices (PWMs). gadem then employs a genetic algorithm (GA), with an embedded EM algorithm to improve starting PWMs, to guide the evolution of a population of spaced dyads toward one whose entropy scores are more statistically significant. Spaced dyads whose entropy scores reach a pre-specified significance threshold are declared motifs. gadem performed comparably with meme on 500 sets of simulated “ChIP” sequences with embedded known P53 binding sites. The major advantage of gadem is its computational efficiency on large ChIP datasets compared to competitors. We applied gadem to six genome-wide ChIP datasets. Approximately, 15 to 30 motifs of various lengths were identified in each dataset. Remarkably, without any prior motif information, the expected known motif (e.g., P53 in P53 data) was identified every time. gadem discovered motifs of various lengths (6–40 bp) and characteristics in these datasets containing from 0.5 to >13 million nucleotides with run times of 5 to 96 h. gadem can be viewed as an extension of the well-known meme algorithm and is an efficient tool for de novo motif discovery in large-scale genome-wide data. The gadem software is available at www.niehs.nih.gov/research/resources/software/GADEM/.
A model for the computer analysis of synchronous DNA distributions obtained by flow cytometry

A new model for obtaining the distributions of cells in the cell cycle by computer analysis of flow cytometry data is proposed. The model is able to analyze distributions from both asynchronous and synchronous cell populations. A culture of HeLa cells is pulse-labeled with tritiated thymidine at various times after synchronization by the mitotic selection method, then analyzed by flow cytometry and autoradiography. The results show good agreement between the percentage S-phase cells determined by the model and by autoradiography.
Effects of high altitude on performance of three different types of work.

To determine the effects of transition from a low altitude to a high altitude on three types of work performance, the rate at which S proceeded from low to high altitude, and the effects of a physical conditioning program. 24 young soldiers were studied at sea level. Their maximum performance on medicine ball putting (an explosive strength task), the bicycle ergometer (a stamina task), and chin-ups (a dynamic strength task) were measured. Half of the Ss participated in a physical conditioning program; Ss daily exercise was based upon exercise at 90% of his own maximum capacity. Eight Ss remained at sea level, 8 Ss ascended to an altitude of 14,110 ft. gradually (1 wk. each at an altitude of 5,200 ft. and 11,400 ft.), 8 Ss went directly to 14,110 ft. within 1 day. It was not possible to predict the amount of depression of performance capacity found at high altitude. Dynamic strength was not affected by high altitude, but explosive strength and stamina were. Explosive strength readapted within 2 wk.; stamin...
Departures from theory of the experimental line profile of Helium(I) 4471.5 Å

Abstract We report discrepancies between the published theoretical calculations of the line profiles for allowed-forbidden transition pairs in neutral helium and observations of the He(I) line near 4471 A in a pulsed arc plasma (nine ∽ 1016 cm-3). Our observations suggest that insufficient wavelength precision in the results reported previously by others has obscured the apparent fact that the peaks in the experimental profile do not follow the wavelength shifts predicted by theory.
A canonical problem in transient radiation--Tthe spherical antenna

The canonical problem of a spherical metal antenna excited at an equatorial gap by an azimuthally independent step voltage is solved. The early-time and late-time behavior of the field is discussed for both nondispersive and dispersive homogeneous isotropic environments. Conclusions are drawn regarding the solution of transient radiation or scattering problems for metal bodies of arbitrary shape.
Application of microfluidic technology to pancreatic islet research: first decade of endeavor.

β-cells respond to blood glucose by secreting insulin to maintain glucose homeostasis. Perifusion enables manipulation of biological and chemical cues in elucidating the mechanisms of β-cell physiology. Recently, microfluidic devices made of polydimethylsiloxane and Borofloat glass have been developed as miniaturized perifusion setups and demonstrated distinct advantages over conventional techniques in resolving rapid secretory and metabolic waveforms intrinsic to β-cells. In order to enhance sensing and monitoring capabilities, these devices have been integrated with analytical tools to increase assay throughput. The spatio-temporal resolutions of these analyses have been improved through enhanced flow control, valves and compartmentalization. For the first time, this review provides an overview of current devices used in islet studies and analyzes their strengths and experimental suitability. To realize the potential of microfluidic islet applications, it is essential to bridge the gap in design and app...
Historical Influences of Volcanism and Glaciation in Shaping Mitochondrial DNA Variation and Distribution in Yellowstone Cutthroat Trout across Its Native Range

Abstract While Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri are probably the best known and one of the most extensively researched of all the subspecies of cutthroat trout, relatively little is known about their genetic structure and evolutionary history. In this study, we assessed the genetic variability and population structure among 50 populations of Yellowstone cutthroat trout over a large portion of their range in Idaho, Montana, Utah, Wyoming, and Nevada using restriction fragment length polymorphism and sequencing analysis of the mitochondrial ND1 and ND2 gene regions. Among the more than 1,000 samples analyzed, a total of 17 haplotypes were observed. These data indicate significant geographic structuring of the genetic variation between drainages and varying levels of reproductive isolation among populations within drainages. Much of this genetic structuring is clearly the product of long-term historical processes (basaltic volcanism and glaciations) that have isolated populations for...
Petrography of Subduction Zone Sandstones from Nias Island, Indonesia

ABSTRACT Rocks on Nias Island, Indonesia can be divided into two tectonostratigraphic units: (1) highly deformed late Oligocene-early Miocene trench deposits (tectonic melange); and (2) Miocene-Pliocene trench slope deposits. Modal point counts of 24 representative samples of sandstones, half from the melange, and half from the slope strata, reveal that they are rich in quartz and sedimentary/metasedimentary lithic fragments. Melange and slope sandstone points are closely clustered on the QFL diagram, however several other differences serve to distinguish them petrographically. Trench slope sandstones contain significant amounts of K-feldspar, polycrystalline quartz, glauconite, and carbonate grains and cement, and the lithic fragment population averages Lv21 Lm 3 Ls26. Melange sandstones contain only small amounts of polycrystalline quartz, insignificant amounts of K-feldspar and glauconite, are cemented by phyllosilicate minerals rather than calcite, and the lithic population averages Lv37 Lm17 Ls46. Similar differences may characterize trench/trench slope deposits elsewhere. The quartzose nature of the Nias sediments indicates that they were derived from the west coast of Sumatra, where early Tertiary quartz-rich sediments and Paleozoic/Mesozoic metamorphic and plutonic rocks are exposed. Nias sandstones have much lower contents of volcanic lithic grains than do most other arc-derived sandstones. This may in part be due to the nonvolcanic source terrane on the west coast of Sumatra, and may also be due to volcanic inactivity in the late Oligocene and paleodrainage away from the trench.
Cutaneous Leishmaniasis in Cuban Immigrants to Texas who Traveled through the Darién Jungle, Panama

Cutaneous leishmaniasis is rarely seen in the United States. Four Cuban immigrants traveled along the same route at different times from Cuba to Ecuador, then northward, including through the Darien Jungle in Panama. These patients had chronic ulcerative non-healing skin lesions and were given a diagnosis of leishmaniasis.
MAPPING OF THE polA LOCUS OF ESCHERICHIA COLI K12: GENETIC FINE STRUCTURE OF THE CISTRON

The close linkage of the glnA gene with polA was exploited to construct a fine structure map of polA by means of generalized transduction with phage P1. Nine different polA- alleles were mapped by recombinational crosses. The results indicate a gene order consistent with previous observations (KELLEY and GRINDLEY 1976a; MURRAY and KELLEY 1979). Three mutations, polA5, polA6 and polA12 map within the "carboxy-terminal" or "large-fragment" portion of the gene in unambiguous order. Four alleles, known to affect the "amino-terminal" portion of the gene, polA107, polA214, polA480ex and polA4113, appear to be closely linked with certain ambiguities in their exact order. All four of these mutations are known to alter the 5' leads to 3' exonuclease activity of DNA polymerase I and three of them result in the conditional lethal polA- phenotype. The polA1 nonsense mutation maps between these two groups in a position consistent with its known effect, production of an amber fragment that includes the 5' leads to 3' exonuclease. The final allele, resA1, is another nonsense mutation that maps at the extreme "amino-terminus" of the cistron.----A number of control experiments were conducted to determine the effects of polA- mutations on the P1-mediated recombinational event. These experiments indicated that abortive transduction occurs quite frequently, but the formation of abortive transductants and segregation of unselected transduced markers among daughter progeny is like that observed by other investigators. There was no evidence that any individual polA- allele behaved in an exceptional fashion during recombination.
Traumatic childhood experiences in the 21st century: broadening and building on the ACE studies with data from the National Child Traumatic Stress Network

The study objectives were to (a) examine the association between total number of trauma types experienced and child/adolescent behavioral problems and (b) determine whether the number of trauma types experienced predicted youth behavioral problems above and beyond demographic characteristics, using a diverse set of 20 types of trauma. Data came from the National Child Traumatic Stress Network’s (NCTSN) Core Data Set (CDS), which includes youth assessed and treated for trauma across the United States. Participants who experienced at least one type of trauma were included in the sample (N = 11,028; age = 1½-18 years; 52.3% girls). Random effects models were used to account for possible intraclass correlations given treatment services were provided at different NCTSN centers. Logistic regression analyses were used to investigate associations among demographic characteristics, trauma, and emotional and behavioral problems as measured by the Child Behavior Checklist (CBCL). Significant dose–response relations ...
MOT-based continuous cold Cs-beam atomic clock

In this paper we report our design and experimental results towards demonstration of a magneto optical trap (MOT)-based cold Cs-beam atomic clock. We generated a continuous cold Cs beam from a Cs MOT by perturbing the MOT potential and measured the longitudinal velocity of the Cs beam to be 7 m/s. In order to separate the atomic beam from the MOT laser beam, we used a one-dimensional optical molasses to deflect the Cs beam through an angle of 30° before the atomic beam enters the microwave cavity. Our Cs beam has an instantaneous atomic flux of 3.6 × 1010 atoms/s when operated in pulsed mode and a continuous flux of 2 × 108 atoms/s. Under current experimental conditions, the observed cold Cs atomic beam parameters infer a short-term, shot-noise limited Allan standard deviation of 2.7 × 10−13 τ−1/2 (τ is the averaging time) for the cold Cs beam clock under development.
An Organizational Ecology of National Self-Help/Mutual-Aid Organizations:

Although a considerable amount of research on modern self-help/mutual aid has been undertaken during the past several decades, studies have yet to address the question What are the organizational dynamics underlying the institutionalization of self-help/mutual aid? As a partial answer to this question, the author describes the central patterns of growth, decline, and persistence of national self-help/mutual-aid organizations, their formal diversification, and the extent to which subpopulations gain market share. In addition to using an organizational—ecological focus to map the trajectory of voluntary organizations, this article builds on resource partitioning theory by applying its central insights to subtypes of organizations. Expansion of self-help/mutual aid is remarkably similar to the trajectories of commercial and bureaucratic populations, but expectations that generalist concentration fosters growth of specialist organizations are not supported. Specialists dominate generalists except among medica...
Prevalence and clinical correlates of co-occurring insomnia and hypersomnia symptoms in depression

Abstract Background The aim was to examine the prevalence and consequences of co-occurring insomnia and hypersomnia symptoms in depressed adults drawn from a representative sample of the U.S. population. Method Data from 687 National Comorbidity Survey Replication (NCS-R) respondents meeting criteria for a major depressive episode (MDE) in the past year were included. Respondents completed clinical interviews that assessed 12-month DSM-IV disorders, impairment, mental health treatment, and depressive symptom severity. Outcomes were compared between respondents who experienced insomnia symptoms-only (N=404), hypersomnia symptoms-only (N=44), both insomnia and hypersomnia symptoms (N=184) and no sleep problems (N=55) during an MDE. Results Insomnia and hypersomnia symptoms co-occurred in 27.7% of respondents with past-year MDEs, most frequently in bipolar spectrum disorders and major depressive disorder with dysthymia. Similar to the insomnia-only group, respondents with co-occurring sleep disturbances had more severe depression, and higher rates of past-year impulse control disorders and suicide planning. Similar to the hypersomnia-only group, respondents with co-occurring sleep disturbances had higher rates of past-year drug use disorders and suicide attempts. Compared to the insomnia-only and no sleep problem groups, respondents with both sleep disturbances were more frequently in mental health treatment, seeing a general practitioner, and taking antidepressants. Limitations The NCS-R is cross-sectional and did not evaluate sleep disorder diagnoses. Conclusions Co-occurring insomnia and hypersomnia symptoms were associated with a more severe MDE. Further research is warranted to more fully understand the joint presentation of insomnia and hypersomnia in depression.
Quantum Computing: From Bragg Reflections to Decoherence Estimates

Abstract : We give an exposition of the principles of quantum computing (logic gates, exponential parallelism from polynomial hardware, fast quantum algorithms, quantum error correction, hardware requirements, and experimental milestones). A compact description of the quantum Fourier transform to find the period of a function-the key step in Shor's factoring algorithm illustrates how parallel state evolution along many classical computational paths produces fast algorithms by constructive interference similar to Bragg reflections in x-ray crystallography. On the hardware side, we present a new method to estimate critical time scales for the operation of a quantum computer. We derive a universal upper bound on the probability of a computation to fail due to decoherence (entanglement of the computer with the environment), as a function of time. The bound is parameter-free, requiring only the interaction between the computer and the environment, and the time-evolving state in the absence of any interaction. For a simple model we find that the bound performs well and decoherence is small when the energy of the computer state is large compared to the interaction energy. This supports a recent estimate of minimum energy requirements for quantum computation.
Male circumcision and risk of HIV infection among heterosexual African American men attending Baltimore sexually transmitted disease clinics.

Background Male circumcision has received international attention as an intervention for reducing HIV infection among high-risk heterosexual men; however, few US studies have evaluated its association with the risk of HIV infection. Methods We analyzed visit records for heterosexual African American men who underwent HIV testing while attending sexually transmitted disease (STD) clinics in Baltimore, Maryland, from 1993 to 2000. We used multivariable binomial regression to evaluate associations between circumcision and the risk of HIV infection among visits by patients with known and unknown HIV exposure. Results Overall, 1096 (2.7%) of 40,571 clinic visits yielded positive HIV test results. Among 394 visits by patients with known HIV exposure, circumcision was significantly associated with lower HIV prevalence (10.2% vs. 22.0%; adjusted prevalence rate ratio [PRR], 0.49 [95% confidence interval [CI], 0.26-0.93]). Conversely, among 40,177 visits by patients with unknown HIV exposure, circumcision was not associated with reduced HIV prevalence (2.5% vs. 3.3%; adjusted PRR, 1.00 [95% CI, 0.86-1.15]), and age >or=25 years old and diagnosis of ulcerative STD were associated with increased prevalence. Conclusions Circumcision was associated with substantially reduced HIV risk in patients with known HIV exposure, suggesting that results of other studies demonstrating reduced HIV risk for circumcision among heterosexual men likely can be generalized to the US context.
Efficient 1,4-addition of α-substituted fluoro(phenylsulfonyl)methane derivatives to α,β-unsaturated compounds

The 1,4-addition of a monofluoromethyl nucleophile to a variety of α,β-unsaturated compounds has been achieved under mild conditions using either phosphines or potassium carbonate at room temperature. α-Substituted fluoro(phenylsulfonyl)methane easily undergoes Michael addition to α,β-unsaturated ketones, esters, nitriles, sulfones, as well as propynoates at room temperature to yield the corresponding adducts in moderate to excellent yields.
Model selection for covariance structures analysis in nursing research

Covariance structures analysis is often used in nursing research to appraise statistical models reflecting complex human health processes. The model selection approach in covariance structures analysis is designed to select the "best" model from a specified set of theoretically defensible, competing alternatives, all of which are viewed as approximations. Model selection criteria explicitly incorporate both model misfit in the population and sampling error to evaluate the set of models. The result is that interpretability of model parameters and goodness-of-fit are enhanced simultaneously. Relative merits of the model selection approach are identified in light of technical concerns, parsimony, and use of scientific theory in nursing.
“Anatometabolic” Tumor Imaging: Fusion of FDG PET with CT or MRI to Localize Foci of Increased Activity

Positron emission tomographic (PET) images of visceral cancers are commonly visualized as "hot spots" of increased activity with relatively little normal anatomy discernable, when 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) is used as the tracer. We describe a method by which computed tomography or magnetic resonance anatomic images can be digitally fused in three dimensions, using a rigid rotate-translate scale model with PET "metabolic" images, to simultaneously display registered anatomic and metabolic information. Such "anatometabolic" fusion images were produced in 10 patients with a variety of visceral cancers. External fiducial markers placed during both the anatomic and the metabolic study, as well as internal anatomic fiducials defined from landmarks observed on reconstructed transmission images, were used to achieve image fusion. The mean error magnitude +/- s.e.m. of fiducial registration in the nine patients with successful realignments was 5.0 +/- 0.8 mm. The mean accuracy in realignment between known anatomic structures seen on both the anatomic study and on the emission PET scan (but not used in realignment) was 6.3 +/- 0.8 mm. Localization of foci of increased FDG uptake to specific anatomic structures was achieved by this method, which represented an enhancement over the rudimentary anatomy available from the emission images alone. Anatometabolic fusion images made using this reasonably simple method should prove useful in the management of patients with cancer and other diseases.
Observer-based adaptive control of a class of bioreactor processes

A stable adaptive observer-based control scheme, requiring on-line measurements of only one of the process states, is suggested for a class of nonlinearly-parametrized uncertain models encountered in bioreactor processes. In the first stage, a fixed observer-based controller is designed for the case when the process parameters are completely known, and, based on a suitable coordinate transformation suggested in this paper, it was shown that the resulting closed-loop system is stable, and that the output errors converge to zero asymptotically. Following that, the observer is used to design a stable adaptive controller in the case when the process growth model is of Monod type with unknown parameters. In both cases the stability and error convergence is demonstrated using suitably chosen Lyapunov functions, while the performance of the resulting closed-loop systems is evaluated through simulations.
Scale Dependence of Solar Heating Rates in Convective Cloud Systems with Implications to General Circulation Models.

Abstract The authors examine 3D solar radiative heating rates within tropical convective–cirrus systems to identify the scales that contribute significantly to the spatial average over a climate model’s grid cell (i.e., its grid mean), and determine their relationship to the cloud field properties (e.g., cloud-top height variation). These results are used to understand the spatial resolution and subgrid-scale cloud property information needed in climate models to accurately simulate the grid-mean solar heating of these systems. The 3D heating rates are computed by a broadband Monte Carlo model for several regional-scale cloud fields [(400 km)2] whose properties are retrieved from satellite data over the tropical western Pacific. The analyses discussed in this paper have identified two key subgrid-scale features within these systems that largely govern the grid-mean heating rates: the variability in the cloud-top height, and the structure of the cloud edge. These features give rise to hot spots—regions of ...