cssi/SciSciGPT-SciSciNet huggingface dataset:
Changes in Bacterial and Archaeal Community Structure and Functional Diversity along a Geochemically Variable Soil Profile

Spatial heterogeneity in physical, chemical, and biological properties of soils allows for the proliferation of diverse microbial communities. Factors influencing the structuring of microbial communities, including availability of nutrients and water, pH, and soil texture, can vary considerably with soil depth and within soil aggregates. Here we investigated changes in the microbial and functional communities within soil aggregates obtained along a soil profile spanning the surface, vadose zone, and saturated soil environments. The composition and diversity of microbial communities and specific functional groups involved in key pathways in the geochemical cycling of nitrogen, Fe, and sulfur were characterized using a coupled approach involving cultivation-independent analysis of both 16S rRNA (bacterial and archaeal) and functional genes (amoA and dsrAB) as well as cultivation-based analysis of Fe(III)-reducing organisms. Here we found that the microbial communities and putative ammonia-oxidizing and Fe(III)-reducing communities varied greatly along the soil profile, likely reflecting differences in carbon availability, water content, and pH. In particular, the Crenarchaeota 16S rRNA sequences are largely unique to each horizon, sharing a distribution and diversity similar to those of the putative (amoA-based) ammonia-oxidizing archaeal community. Anaerobic microenvironments within soil aggregates also appear to allow for both anaerobic- and aerobic-based metabolisms, further highlighting the complexity and spatial heterogeneity impacting microbial community structure and metabolic potential within soils.
The Effects of Word Processing on Written Composition

AbstractIn the present study, the effects of a year-long word processing program on holistic writing skills were examined. Learners in the treatment group used a word processor three times per week to complete writing assignments. Students in the control group used conventional pen- and-paper writing techniques to complete their writing assignments. An analysis of writing samples taken upon completion of this study suggested that word processing alone was of little consequence for able learners, hut proportionately most effective for low-achieving students. These effects were found despite logistical problems encountered during the study that probably precluded more dramatic results.
The action of a β‐adrenoreceptor agonist on gastric acid secretion in dogs

1. In conscious dogs with gastric fistulae and Heidenhain pouches, isoprenaline (0.75 microgram kg-1 h-1) brought about an increase in methacholine stimulated gastric acid and pepsin secretion from the innervated mucosa. 2. The increase in acid consisted for the most part of the replacement of the usual post-peak fade by a sustained plateau and of the replacement of the usual wait for the spontaneous peak by immediate stimulation of secretion.
The New South's New Frontier: A Social History of Economic Development in South-western North Carolina . By Stephen Wallace Taylor. Gainesville: University Press of Florida, 2001. Pp. xi, 186. $55.00.

Economic development is a fragile thing. This book examines the transformation of the southwestern corner of North Carolina from a region with intermittent prosperity in the early part of the twentieth century to an economically stagnant region that has not shared in the tremendous recent economic growth in the southeastern United States. For much of the nineties, this southeastern region from North Carolina to Georgia was the fastest growing region in the United States. What happened to the mountain region and how did it get left out? Taylor rejects simplistic models of an isolated mountain region exploited by the Tennessee Valley Authority (TVA) and outside capitalists. Instead, he presents the process of economic change as similar to development in the rest of the South: that is, the result of an interplay between outsiders and mountain people who were never economically isolated from the rest of the country, and who were adept at taking advantage of whatever economic opportunities presented themselves. Many local residents, for example, were very keen about the establishment of a national park in this part of the Smoky Mountains because they thought it would bring in tourists and boost the local economy. Similarly, many locals supported the construction of the Fontana Dam on the Little Tennessee River; also hoping it would bring economic benefits to the region. Ultimately, however, the result was not one they wanted or intended.
Imaging in turbulence beyond diffraction limits

We discuss the nature and general properties of the effect with regard to the imaging through the turbulent atmosphere. This new effect utilizes the medium inhomogeneities as a part of the optical system to obtain the resolution beyond the diffraction limit. Turbulence superresolution effect relates to the focusing properties of the random medium. We discuss some general properties of image distortions by random refractive medium and present the experimental results revealing important statistical connections between global properties of distorted image and superresolution events. We present the results of the postdetection processing of the short- exposure images which is capable to preserve and accumulate information beyond the diffraction limit.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A reliability-based measurement of interoperability for systems of systems

The increasing complexity of net-centric systems of systems requires each system to be interoperable to achieve operational goals. Interoperability can be considered a metric of an architecture, and must be understood by decision makers as early as the conceptual design phase. Many measurements of interoperability of system pairs exist, but an architecture-level method for calculating interoperability of a system of systems is not currently available. This research presents a flexible, intuitive measure of interoperability of system pairs within a potential architecture performing a set of resource exchanges. It draws from reliability theory to incorporate system requirements and to link the interoperability of a system of systems with operational metrics of performance. This measure of interoperability could provide decision makers with information about an architecture and allow them to compare existing and potential systems of systems during the early phases of acquisition.
SURVIVORS OF MOTOR VEHICLE TRAUMA: AN ANALYSIS OF SEAT BELT USE AND HEALTH CARE UTILIZATION

Objective: To determine whether the protective effects of seat belt use on acute injury are followed by corresponding reductions in outpatient health care utilization. Design: Retrospective cohort analysis. Setting: Northern California Region Kaiser Health Plan hospitals and medical offices. Patients: All Kaiser Foundation Health Plan members injured in motor vehicle crashes in Santa Clara County during one year (total number of patients=246). Measurements and main results: 54% of the study participants had been wearing seat belts at the time of injury, and 46% had not been. The belted patients had fewer head injuries (30% vs 50%, p<0.05), better mean Injury Severity Scale scores (4.3 vs 7.4, p<0.05), and smaller mean hospital charges ($8,580 vs $16,209, p<0.05). However, the effects of injury did not end upon discharge from the trauma center; the patients averaged about eight outpatient visits during the subsequent year, a rate almost double their prior use. In contrast to inpatient measures of utilization, the patients who had been wearing seat belts at the time of injury had more outpatient visits during the year after injury than had their unbelted counterparts (9.0 vs 7.1, p<0.05). This discrepancy was not explained by differences in amounts of utilization during the year before injury, which were similar in the two groups (4.4 vs 4.8, p=NS). Overall, general internists provided the most follow-up care and accounted for the largest discrepancy in utilization between the belted and unbelted patients. Conclusions: Seat belt use does not result in lower utilization of follow-up outpatient services in the year following injury. However, the beneficial effects on acute care utilization more than offset the marginal effects on subsequent medical services utilization.
Resilient Virtual Clusters

Clusters of computers can provide, in aggregate, reliable services despite the failure of individual computers. System-level virtualization is widely used to consolidate the workload of multiple physical systems as multiple virtual machines (VMs) on a single physical computer. A single physical computer thus forms a \fIvirtual cluster\fP of VMs. A key difficulty with virtualization is that the failure of the virtualization infrastructure (VI) often leads to the failure of multiple VMs. This is likely to overload "cluster computing" resiliency mechanisms, typically designed to tolerate the failure of only a single node at a time. By supporting recovery from failure of key VI components, we have enhanced the resiliency of a VI (Xen), thus enabling the use of existing "cluster computing" techniques to provide resilient virtual clusters. In the overwhelming majority of cases, these enhancements allow recovery from errors in the VI to be accomplished without the failure of more than a single VM. The resulting resiliency of the virtual cluster is demonstrated by running two existing "cluster computing" systems while subjecting the VI to injected faults.
Inherited mutations in pheochromocytoma and paraganglioma: why all patients should be offered genetic testing.

Pheochromocytomas (PCC) and paragangliomas (PGL) are neuroendocrine tumors that, although rare, are an important cause of secondary hypertension because of the high morbidity and mortality. PCC/PGL are still thought of as the “tumor of tens,” with 10 % being hereditary; however, recent population based studies suggest that up to 32 % of patients have a germline mutation in one of the known common susceptibility genes (including NF1, VHL, RET, SDHB, SDHD, and SDHC). Despite this, most patients in the United States are not referred for clinical genetic testing by their physicians. We aimed to examine the mutation prevalence in a clinic-based population in the United States. We performed a retrospective chart review of 139 consecutive patients with PCC/PGL from the medical genetics clinic at the hospital of the University of Pennsylvania from January 2004 through February 2012. We found a 41 % overall mutation detection rate. Twenty-six percent of the cohort had a mutation in the SDHB or SDHD genes. Of patients with at least one PGL tumor outside the adrenal gland, 53 % had an identified mutation. Forty-one percent of the cohort had a heritable mutation. The most commonly mutated gene was SDHB, which carries the highest risk of malignancy. These data, together with American Society of Clinical Oncology guidelines suggesting that genetic testing be performed if the risk of a hereditable mutation is at least 10 % or if it will affect medical management, strongly suggest that all patients with PCC/PGL should undergo clinical genetic testing.
UTILIZATION OF FRACTAL IMAGE MODELS IN MEDICAL IMAGE PROCESSING

One of the more successful engineering applications of fractal geometry has been the utilization of fractal image models in medical image processing. These applications have included tissue characterization studies, textural image segmentation, and image restoration using fractal constraints. The class of fractal models used in medical image processing and the techniques used to estimate the fractal dimension associated with these models will be reviewed. An image segmentation algorithm that utilized a fractal textural feature and formulated the segmentation process as a configurational optimization problem is presented. The configurational optimization method allows information about both, the degree of correspondence between a candidate segment and an assumed textural model, and morphological information about the candidate segment to be used in the segmentation process. To apply this configurational optimization technique with a fractal textural model however, requires the estimation of the fractal dimension of an irregularly shaped candidate segment. The potential utility of a discrete Gerchberg-Papoulis bandlimited extrapolation algorithm to the estimation of the fractal dimension of an irregularly shaped candidate segment is also discussed.
Surface fracturing of armatures within helical flux-compression generators

Summary form only given, as follows.Tubes of aluminum and of copper filled with C-4 high-explosive were tested during this study of high strain rate effects within thin metallic structures performed as an adjunct to helical flux-compression generator research at the University of Missouri-Rolla. Focusing on the stresses within a relatively thin metallic structure when brisant explosives abutting the structure are detonated, this study directly affects the understanding of flux cut-off and high strain-rate resistivity changes in an expanding armature. The detonation wave is compressive, and the shock waves resulting from its transmission into a thin metallic structure cause both compressive and tensile regions, posing an extremely complex stress field within the structure. This stress field bears directly upon how the tube structure fractures when it is impulsively loaded by high pressure gases as a result of the detonation. Longitudinal cracks characteristically develop in the outer surface of the armature tubing within about four diameters of the end containing the detonator, but the cracks do not extend as the tubing expands under explosive pressurization. Such cracks are a cause of flux cut-off in the generators, a cause that can be isolated during generator operation given proper generator construction. Surface cracking of the armatures was modified by the utilization of bimetallic armature construction, and by the introduction of polymeric materials between the explosive charge and the armature tube.
Existence and estimation of impropriety in real rhythmic signals

Impropriety in complex signal processing has been studied and used primarily in a communications context, but also in some cases where complex signals are generated by adding real signals in quadrature. We discuss the meaning of impropriety, and the associated use of complementary statistics, when a real-valued random process is improper in the frequency domain. Through the use of modulation signal models, spectral impropriety can be connected explicitly to the frequency and phase of components belonging to a periodic, or more generally rhythmic, modulator waveform. We give theoretical signal models and provide an example of complementary analysis on underwater propeller noise from a merchant ship.
The Renin–Angiotensin–Aldosterone System: A Personal Perspective and Festschrift for John H. Laragh, MD

John Laragh has been a great inspiration to me and many others in the field of hypertension research. His inquisitive mind, deep knowledge of physiology and medicine, and keen clinical insights led him to discoveries and innovation that were critical to our current understanding of the renin– angiotensin–aldosterone system (RAAS) and to the development of effective therapies for hypertension. I first met John in the 1970s during one of his visits to Mississippi, along with his research group, to meet with our Department of Physiology, led at that time by Arthur Guyton. My lab was engaged in basic research studies on the intrarenal actions of angiotensin II (Ang II) in regulating glomerular filtration rate, tubular reabsorption, and longterm control of blood pressure, and I was deeply impressed by the work of John and his colleagues at Cornell. Teprotide (SQ-20881), the peptide inhibitor of angiotensin-converting enzyme (ACE), and peptide antagonists of the ANG II type 1 receptor were just becoming available, and I was eager to use these compounds to investigate the intrarenal role of Ang II in long-term blood pressure regulation. One major reason for my interest was John’s previous studies that showed that low-dose Ang II infusions in humans had powerful effects on blood pressure that were not only sustained but also actually amplified during several days of infusion. 1 The progressive hypertensive effect of Ang II was related to sodium balance and was even more impressive than that of aldosterone. The effects of Ang II contrasted with those of norepinephrine, which had progressively weaker blood pressure effects during several days of infusion and caused either natriuresis or no change in sodium balance. 1 In a seminal series of studies in humans, John and his colleagues found that Ang II controls sodium balance and blood pressure not only through stimulation of aldosterone but also by direct actions on the kidneys. A paragraph in his 1965 paper in the Journal of Clinical Investigation 1 was especially enlightening:
Reducing delay with dynamic selection of compression formats

Internet computing is facilitated by a remote execution methodology in which programs transfer to a destination for execution. Since the transfer time can substantially degrade the performance of remotely executed (mobile) programs, file compression is used to reduce the amount of data that is transferred. Compression techniques however, must trade off compression ratio for decompression time, due to the algorithmic complexity of the former, since the latter is performed at run-time in this environment. In this paper, we define the total delay as the time for both the transfer and the decompression of a compressed file. To minimize the total delay, a mobile program should be compressed in the best format for minimizing the delay. Since both the transfer time and the decompression time are dependent upon the current underlying resource performance, selection of the "best" format varies and no one compression format minimizes the total delay for all resource performance characteristics. We present a system called Dynamic Compression Format Selection (DCFS) for the automatic and dynamic selection of competitive compression formats based on the predicted values of future resource performance. Our results show that DCFS reduces the total delay imposed by the compressed transfer of Java archives (.jar files) by 52% on average for the networks, compression techniques and benchmarks studied.
A Simple Model for Electron Diffusion Magnetothermopower

An investigation is made of the electron diffusion component of magnetothermopower of metals based on simple transport theory arguments. With the aid of some approximations an expression is obtained which relates the change in thermopower with magnetic field, ΔS(H, T) = S(H, T) − S(0, T), to the magnetoresistance. Kohler's rule then leads to a number of qualitative predictions for the temperature and field dependence of ΔS(H, T). Some of those predictions are in fair accord with observation. However, based on presently available data, it is concluded that total measured change in thermopower is probably due to changes in both diffusion and phonon-drag contributions. Der Einflus eines Magnetfeldes auf den Diffusionsanteil der thermoelektrischen Kraft wird unter Annahme der Transporttheorie untersucht. Mit Hilfe einiger Naherungen wird ein Ausdruck fur das Verhaltnis zwischen der durch das durch das Magnetfeld hervorgerufenen Anderung der Thermokraft, ΔS(H, T) = S(H, T) − S(0, T), und der magnetischen Widerstandsanderung erhalten. Auf Grund der Kohlerschen Regel lassen sich dann einige qualitative Voraussagen uber die Beziehung zwischen ΔS(H, T), Temperatur und Magnetfeld machen, die teiweise mit experimetellen Resultaten gut ubereinstimmen. Jedoch zeigen die Resultate, das die gesamte Anderung der Thermokraft sowohl auf den Diffusions- als auch auf den Phonon-Drag-Anteil zuruckzufuhren ist.
Factors associated with older patients’ satisfaction with care in an inner-city emergency department

Abstract Study Objectives: We sought to assess older patients' satisfaction with care in the emergency department and to identify factors associated with global satisfaction with care. Methods: We performed a prospective cohort study of 778 patients 65 years of age and older presenting to an urban academic ED between 1995 and 1996, of whom 79% were black and 63% were female. A baseline survey at presentation to the ED asked for demographic information, medical history, and health-related quality of life information. A follow-up satisfaction survey asked patients to rate the care they received in the ED on a 5-point Likert scale (1=excellent, 5=poor). Overall satisfaction with care, dichotomized into responses of "excellent" versus all others, was the primary dependent variable in our bivariate analyses. Results: Of respondents, 40% rated their ED care as "excellent." Variables significantly correlated with high satisfaction include having the perception of time spent in the ED as not "too long," having the emergency physicians and nurses clearly answer patients' questions, having a relationship of trust with an ED staff member, being told why tests were done, feeling involved in decisions about care as much as they wanted, having pain addressed fully, having a perception of greater health status, and having fewer comorbid conditions at the time of the ED visit. Results may be applicable only to urban academic EDs and may be limited by time elapsed between ED visits and follow-up surveys. Conclusion: To improve quality of care for older adults in the ED, physicians should be more attentive to older patients' concerns and questions, recognize and aggressively treat pain, and reduce the patients' perception of a long waiting time. [Nerney MP, Chin MH, Jin L, Karrison TG, Walter J, Mulliken R, Miller A, Hayley DC, Friedmann PD. Factors associated with older patients' satisfaction with care in an inner-city emergency department. Ann Emerg Med. August 2001;38:140-145.]
Voltage-drop calculations and power-flow studies for rural electric distribution lines

The history of distribution system voltage-drop and loss calculation from paper-and-pencil methods to full three-phase power flow calculations using the digital computer is examined. The methods discussed include an approach that allows unbalanced operation (such as an open-wye line) to be analyzed accurately. It is suggested that intelligent use of the models will entail using the more detailed models only if necessary, thereby avoiding unnecessary computational expense. It is much more important to use a reasonable value for the load power factor than to account exactly for every small unbalance in the line impedances. Recommendations to aid the practicing engineer in the choice of the best analytical tools are offered. >
Dithered GMD Transform Coding

The geometric mean decomposition (GMD) transform coder (TC) was recently introduced and was shown to achieve the optimal coding gain without bit loading under the high bit rate assumption. However, the performance of the GMD transform coder is degraded in the low rate case. There are mainly two reasons for this degradation. First, the high bit rate quantizer model becomes invalid. Second, the quantization error is no longer negligible in the prediction process when the bit rate is low. In this letter, we introduce dithered quantization to tackle the first difficulty, and then redesign the precoders and predictors in the GMD transform coders to tackle the second. We propose two dithered GMD transform coders: the GMD subtractive dithered transform coder (GMD-SD) where the decoder has access to the dither information and the GMD nonsubtractive dithered transform coder (GMD-NSD) where the decoder has no knowledge about the dither. Under the uniform bit loading scheme in scalar quantizers, it is shown that the proposed dithered GMD transform coders perform significantly better than the original GMD coder in the low rate case.
Discovery of geometry theorems: avoiding isomorphic situation descriptions

Automation of systematic theorem discovery in geometry is still a relatively unexplored area. The authors have recently developed a "generate-and-test" method that combines incremental generation of geometric situation descriptions with a prover to test their consistency; descriptions found to be inconsistent lead to theorems. However, large number of isomorphic descriptions of geometry situations cause the combinatorial complexity of that method to be very high. This paper outlines that method and presents an algorithm that avoids generation of isomorphic descriptions. This is performed by associating permutations with the arguments of each predicate symbol, under which literals involving that predicate symbol preserve their meaning. >
Contributions of Conventional and Heavy-Chain IgG to Immunity in Fetal, Neonatal, and Adult Alpacas

In addition to conventional immunoglobulins, camelids produce antibodies that do not incorporate light chains into their structures. These so-called heavy-chain (HC) antibodies have incited great interest in the biomedical community, as they have considerable potential for biotechnological and therapeutic application. Recently, we have begun to elucidate the immunological functions of HC antibodies, yet little is known about their significance in maternal immunity or about the B lymphocytes that produce them. This study describes the application of isotype-specific reagents toward physiological assessments of camelid IgGs and the B cells that produce them. We document the specificities of monoclonal antibodies that distinguish two conventional IgG1 isotypes and two HC IgG3 variants produced by alpacas. Next, we report that the relative concentrations of five isotypes are similar in serum, milk, and colostrum; however, following passive transfer, the concentrations of HC IgG2 and IgG3 declined more rapidly than the concentration of conventional IgG1 in the sera of neonates. Finally, we assessed the distribution of B cells of distinct isotypes within lymphoid tissues during fetal and adult life. We detected IgG1, IgG2, and IgG3 in lymphocytes located in lymph node follicles, suggesting that HC B cells affinity mature and/or class switch. One IgG3 isotype was present in B cells located in ileal Peyer's patches, and one conventional IgG1 isotype was detected in splenic marginal zone B cells. Our findings contribute to the growing body of knowledge pertaining to HC antibodies and are compatible with functional specialization among conventional and HC IgGs in the alpaca.
New class of nonlinear systematic error detecting codes

A code C detects error e with probability 1-Q(e),ifQ(e) is a fraction of codewords y such that y, y+e/spl isin/C. We present a class of optimal nonlinear q-ary systematic (n, q/sup k/)-codes (robust codes) minimizing over all (n, q/sup k/)-codes the maximum of Q(e) for nonzero e. We also show that any linear (n, q/sup k/)-code V with n /spl les/2k can be modified into a nonlinear (n, q/sup k/)-code C/sub v/ with simple encoding and decoding procedures, such that the set E={e|Q(e)=1} of undetected errors for C/sub v/ is a (k-r)-dimensional subspace of V (|E|=q/sup k-r/ instead of q/sup k/ for V). For the remaining q/sup n/-q/sup k-r/ nonzero errors, Q(e)/spl les/q/sup -r/for q/spl ges/3 and Q(e)/spl les/ 2/sup -r+1/ for q=2.
Increasing accuracy and efficiency in FE computations of the Leray‐Deconvolution model

This article develops, analyzes, and tests a finite element method for approximating solutions to the Leray-deconvolution regularization of the Navier-Stokes equations. The scheme combines three ideas to create an accurate and effective algorithm: the use of an incompressible filter, a linearization that decouples the velocity-pressure system from the filtering and deconvolution operations, and a stabilization that works well with the linearization. A rigorous and complete numerical analysis of the scheme is given, and numerical experiments are presented that show clear advantages of the scheme. © 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 28: 720–736, 2012
A system architecture for distributed control loop applications (extended abstract)

In this position paper we motivate an important emerging class of applications that cooperate across a complex distributed computational fabric containing elements of widely varying capabilities, including physical and virtual sensors, actuators, and high-performance computational clusters and grids. We identify typical requirements of such applications and identify several novel research challenges that such applications pose. We sketch an evolving architecture developed as part of the Media Broker project at Georgia Tech that solves a subset of the problems presented.
A new deep-sea species of epibenthic acorn worm (Hemichordata, Enteropneusta)

Individuals of an enteropneust, Tergivelum baldwinae n. gen., n. sp. were videotaped at a depth of about 4 km in the eastern Pacific and collected by a remotely operated vehicle. The living worms range in length from 9 to 28 cm and are dark brown anteriorly and beige posteriorly. The proboscis is shaped like a shallow dome, indented on either side by a laterodorsal fossa housing a prominent proboscis nerve. The collar comprises a thin transverse crest dorsally and two laterally projecting lips on either side of the mouth ventrally. The mouth is oriented parallel to the substratum and is flanked by large left and right buccal muscles (contrasting with the rudimentary musculature elsewhere in the body). The respiratory pharynx of the trunk extends far anteriorly so that much of it lies dorsal to the mouth opening. The gill bars are not joined by synapticles. The laterodorsal body wall at the anterior extremity of the trunk extends as two conspicuous flaps (back veils) that run posteriorly as unattached coverings over the anterior 30-50% of the trunk. On either side of the midline, the body wall of the trunk is extended as a narrow lateroventral fold. Within the trunk runs the intestine, which lacks hepatic sacculations and opens at an anus at the posterior end of the body. Frame analysis of videotapes suggests that the worm can secrete a mass of mucus around the body to facilitate demersal drifting from one epibenthic foraging site to the next. We include a preliminary phylogenetic analysis based on rDNA sequences from T. baldwinae n. gen., n. sp. and additional deep-sea enteropneusts not yet formally described taxonomically (sequence data place them unexpectedly close to ptychoderids). Until more is known about the group as a whole, it is prudent to leave family level classification of T. baldwinae n. gen., n. sp. as incertae sedis.
New Insights into the Regulation of Gametogenesis by Retinoic Acid

Retinoic acid, an essential regulator of gametogenesis. It is well established that retinoic acid, synthesized from the dietary vitamin, retinol, is required for male and female gametes to enter meiosis. In female mice, meiosis is initiated soon after determination of gonadal sex, which is completed by 12.5 days post coitum (dpc). This initiation can be blocked by retinoic acid antagonists or by knockout-out of the RA-regulated gene, Stra8 [1, 2]. In contrast to what happens in the fetal ovary, gonocytes in a 12.5 dpc fetal testis enter G0 of the cell cycle and do not divide again until after birth. The exit of male gonocytes from the cell cycle is not due to an inability of these cells to respond to retinoic acid, for incubation of a fetal testis with retinoic acid causes the gonocytes to enter meiosis [3]. Neither is this exit due to a lack of synthesis of retinoic acid, for the mesonephros of both sexes express ALDH1A2, the rate-limiting enzyme in retinoic acid biosynthesis [3]. However, at 12.5 dpc, testicular retinoic acid concentration is only 20% of the ovarian concentration, due to the testicular expression of CYP26B1, an enzyme that converts retinoic acid to inactive metabolites [2]. The importance of this expression is evident in the fact that in fetal Cyp26b1 null mice, testicular retinoic acid levels are elevated 3-fold, and gonocytes initiate meiosis at 12.5 dpc [4]. Thus, the initiation of meiosis is determined by the availability of retinoic acid and not by the genetic sex of the gonocytes.
Experimental support for a resource-based mechanistic model of invasibility

Recent theory has suggested a mechanistic relationship between resource availability, competition and invasibility. In a field experiment, in which we manipulated resources and competition, we confirmed that changes in resource availability affected competition intensity, which in turn affected invasibility. We found that fluctuations in resource availability of as short as a few weeks had a large impact on plant invasion success (survival and percentage cover), including up to 1 year following the fluctuations. If resource availability is a primary mechanism controlling invasibility, it may serve as a unifying concept that can integrate earlier ideas regarding invasibility. The results emphasize the important role of history in the invasion process, particularly the occurrence of stochastic, short-lived events that temporarily reduce or suspend competition and increase invasibility. Therefore, it may be very difficult, or even impossible, to reconstruct the ecology of particular invasions after the fact.
Origins and consequences of age at first drink: I. Associations with substance-use disorders, disinhibitory behavior and psychopathology, and P3 amplitude.

Background: Although an early age at first drink has been repeatedly associated with substantially elevated rates of alcoholism, the mechanisms underlying this association remain unclear. We investigated whether the association of age at first drink (AFD) with alcoholism was more consistent with the hypothesis that the former causes the latter or the hypothesis that both are manifestations of some common vulnerability. Methods: We investigated whether substance use and mental health disorders, education, IQ, and personality were associated with AFD in a sample of 2670 adults; whether P3 amplitude was associated with AFD in a sample of 1127 17 year olds; and whether indicators of disinhibitory psychopathology assessed at age 11 predicted AFD by age 14 in a sample of 1343 adolescents. Results: In adults, AFD was associated not only with alcohol dependence, but also with a broad array of indicators of disinhibitory behavior and psychopathology including nicotine dependence, illicit drug abuse and dependence, conduct disorder, antisocial personality disorder, underachievement in school, and the personality trait of constraint. In 17 year olds, AFD was also associated with reduced P3 amplitude, a well-documented psychophysiological marker of alcoholism risk. Finally, in the early-adolescence sample, measures of behavioral disinhibition, including oppositionality, hyperactivity/impulsivity, and inattentiveness assessed at age 11 predicted drinking onset by age 14. Conclusions: Our findings indicated that AFD is not specifically associated with alcoholism but rather is correlated with a broad range of indicators of disinhibited behavior and psychopathology. Moreover, individuals who first drink at a relatively early age manifest elevated rates of disinhibitory behavior and psychopathology before they first try alcohol. Taken together, these findings suggest that the association of AFD with alcoholism reflects, at least in part, a common underlying vulnerability to disinhibitory behavior. Whether an early AFD directly influences risk of adult alcoholism remains unclear.
Virtual Laboratory for Electrical Circuit Course

A virtual laboratory for an introductory laboratory course in circuit analysis in Electrical Engineering Technology program is developed that can replace the traditional laboratory setup by an approach based on data acquisition (DAQ) instrumentation. The project utilizes LabVIEW software and DAQ board (Model PCI-6024E) both from National Instruments. The PCI-6024E is a multifunction I/O device having 8 digital I/O lines, 12 bit 16 single ended analog input lines, and two 12 bit analog output lines. The undergraduate laboratories have been poorly equipped due to the rising cost of laboratory instruments. This trend has created a strong market for laboratory instruments based on personal computers. LabVIEW provides a low-cost solution for laboratory instrumentation compared to its traditional counterpart since appropriate software, operating through a plug-in DAQ board, is readily available at a very low-cost. The LabVIEW can model standard laboratory instruments while offering more flexibility as it is software based. The combination of LabVIEW and available plug-in hardware enables the virtual instrument to be modified whenever needs change. This instrumentation system can be produced at a fraction of the cost of traditional instruments. Due to LabVIEW?s graphical nature data can be easily presented in any forms such as charts, graphs, etc. The final product of this project will be used to teach the laboratory course in-class as well as via Internet so that students can take the course on the web which is the trend of education now.
Fahrenholzia texana, new species, with a key to the United States species of Fahrenholzia (Anoplura: Hoplopleuridae)

This species is described from specimens collected in are Cameron County, Texas, from the Texas spiny mouse, Liomys irroratus texensis Merriam. Its taxonomic details illustrated, as are important taxonomic characters of the six species of the genus that are keyed.
Generation of highly uniform magnetic fields with magnetized wedges

A novel method of producing a highly uniform magnetic field by means of permanently magnetized wedges is presented. The method uses a pair of central wedges to generate a primary field and pairs of compensating blocks to improve the field uniformity. The geometry of the central wedges and compensating blocks are determined by an analytic procedure. Using the method, magnetic structures can be designed that allow access to the uniform field over a solid angle of approximately 2/spl pi/ steradians.
Ultrasonic wavefront propagation in an inhomogeneous medium, the female breast

Ultrasound measurements at 3 and 4 MHz of a large population of wavefronts transmitted through female breasts show that the wavefront amplitude distribution is Rayleigh. This finding implies that strong scattering and/or refraction are the dominant causes of distortion. The wavefront received from an inhomogeneous medium is the superposition of an incident wave plus a scattered wave. If the scattered field is weak, the received field is dominated by the incident field and the wavefront amplitude distribution is Rician. If the scattered field is strong, the received field is primarily the scattered field and the wavefront amplitude distribution is Rayleigh. If, in addition to scattering, refraction between bodies of different refractive indexes occurs, the total net effect on the wavefront is the same as for strong scattering. This is what the authors have observed in the highly refractive female breast. >
Performance modeling for multilevel communication in SHMEM

The field of high-performance computing (HPC) is currently undergoing a major transformation brought upon by a variety of new processor device technologies. Accelerator devices (e.g. FPGA, GPU) are becoming increasingly popular as coprocessors in HPC, embedded, and other systems, improving application performance while in some cases also reducing energy consumption. The presence of such devices introduces additional levels of communication and memory hierarchy in the system, which warrants an expansion of conventional parallel-programming practices to address these differences. Programming models and libraries for heterogeneous, parallel, and reconfigurable computing such as SHMEM+ have been developed to support communication and coordination involving a diverse mix of processor devices. However, to evaluate the impact of communication on application performance and obtain optimal performance, a concrete understanding of the underlying communication infrastructure is often imperative. In this paper, we introduce a new multilevel communication model for representing various data transfers encountered in these systems and for predicting performance. Three use cases are presented and evaluated. First, the model enables application developers to perform early design-space exploration of communication patterns in their applications before undertaking the laborious and expensive process of implementation, yielding improved performance and productivity. Second, the model enables system developers to quickly optimize performance of data-transfer routines within tools such as SHMEM+ when being ported to a new platform. Third, the model augments tools such as SHMEM+ to automatically improve performance of data transfers by self-tuning internal parameters to match platform capabilities. Results from experiments with these use cases suggest marked improvement in performance, productivity, and portability.
Autoantibodies associated with peripheral neuropathy

High titers of serum antibodies to neural antigens occur in several forms of neuropathy. These include neuropathies associated with monoclonal gammopathy, inflammatory polyneuropathies, and paraneoplastic neuropathies. The antibodies frequently react with glycosylated cell surface molecules, including glycolipids, glycoproteins, and glycosaminoglycans, but antibodies to intracellular proteins have also been described. There are several correlations between antibody specificity and clinical symptoms, such as anti-MAG antibodies with demyelinating sensory or sensorimotor neuropathy, anti-GM1 ganglioside antibodies with motor nerve disorders, antibodies to gangliosides containing disialosyl moieties with sensory ataxic neuropathy and Miller-Fisher syndrome, and antibodies to the neuronal nuclear Hu antigens with paraneoplastic sensory neuronopathy. These correlations suggest that the neuropathies may be caused by the antibodies, but evidence for a causal relationship is stronger in some examples than others. In this review, we discuss the origins of the antibodies, evidence for and against their involvement in pathogenic mechanisms, and the implications of these findings for therapy.
Using Difference Scores in Making Screening and Placement Decisions

This paper presents a step-by-step procedure for finding the probability of occurrence of the difference between test scores and the probalitily of occunerce of errors of measurement, This procedure is useful ininterpreting test results to parents and in making placement decisions. Difference scores are often used in the placement of students in learning disabilities and remedial reading programs. This type of profile analysis is hazardous unless the reliability of the pairs of tests is taken into account.
Efficacy of social cognition remediation programs targeting facial affect recognition deficits in schizophrenia: A review and consideration of high-risk samples and sex differences

Schizophrenia patients suffer from significant social functioning deficits. Social cognition, particularly facial affect recognition (FAR), is an important predictor of functional outcome. Recently, investigators developed numerous social cognition remediation programs targeting FAR deficits with the goal of improving social functioning and quality of life in schizophrenia patients. This article builds on Horan et al.'s (2008) comprehensive review and Kurtz and Richardson's (2012) meta-analysis of a broad range of social cognition remediations, by systematically reviewing efficacy of empirically based remediations in schizophrenia specifically targeting FAR (across 23 studies), and their potential functional benefits. We describe each FAR-based social cognition remediation program, which may aid clinical scientists and clinicians in selecting programs for further study and practice. We critically evaluate limitations of FAR remediation programs and applications. Our review concludes FAR remediation programs are strongly efficacious in improving FAR performance and functional status in schizophrenia. Importantly, we provide rationale for and recommend that future research consider (as yet underexplored) sexual dimorphisms in FAR remediation effects, and examine FAR remediation in clinical high-risk for psychosis populations. The goal is to mitigate deficits, perhaps hinder illness onset, and individually tailor treatments across the psychosis continuum in a way that maximally aids those in greatest need.
Synergy between preactivated photofrin-II and tamoxifen in killing retrofibroma, pseudomyxoma and breast cancer cells.

Exposure of photoactive compounds to light prior to their use in biological systems (preactivation) results in the generation of tumour cell specific metastable cytotoxic species that are no longer dependent on the light energy. Thus, preactivation renders the photoactive compounds suitable for systemic use. We have examined the in vitro effect of preactivated photofrin-II and tamoxifen in retroperitoneal fibroma, pseudomyxoma and male breast carcinoma cell lines. These cells were found to be non-responsive to tamoxifen and were negative for oestrogen receptors. Incubation of these cells with 0.5 μg/ml preactivated photofrin-II and tamoxifen (< 10−6 mol/l) resulted in a significantly enhanced (P < 0.001) inhibition of DNA synthesis compared with either agent alone. This synergistic effect between tamoxifen and preactivated photofrin-II was determined by multiple drug effect analysis. Treatment of cells with preactivated photofrin-II did not cause the increased expression of oestrogen receptors. These observations suggest that a combination of antihormonal drugs with preactivated compounds may be of clinical value.
Improving logging and recovery performance in Phoenix/App

Phoenix/App supports software components whose states are made persistent across a system crash via redo recovery, replaying logged interactions. Our initial prototype force logged all request/reply events resulting from intercomponent method calls and returns. We describe an enhanced prototype that implements: (i) log optimizations to improve normal execution performance; and (ii) checkpointing to improve recovery performance. Logging is reduced in two ways: (1) we only log information required to remove nondeterminism, and we only force the log when an event "commits" the state of the component to other parts of the system; (2) we introduce new component types that provide our enhanced system with more information, enabling further reduction in logging. To improve recovery performance, we save the values of the fields of a component to the log in an application "checkpoint". We describe the system elements that we exploit for these optimizations, and characterize the performance gains that result.
Cervicitis resulting from turpentine irritation

Abstract Two cases demonstrating similar characteristic lesions of the cervix caused by turpentine used in douche preparations are described. Lesions of this nature must be differentiated from carcinoma of the cervix, syphilitic lesions of the cervix, and tuberculosis of the cervix. A careful review of the literature failed to reveal any reports of lesions of a like nature.
Exciton Physics in Transition-Metal Dichalcogenides at the Atomic Scale

We present an atomistic model for excitons in monolayer transition-metal dichalcogenides consistent with recent experiments. Using this model we show how to extend exciton lifetimes, which could be important for future optoelectronic applications.