cssi/SciSciGPT-SciSciNet huggingface dataset:
Women, Evil, and Grey Zones

Gray zones, which develop wherever oppression is severe and lasting, are inhabited by victims of evil who become complicit in perpetrating on others the evils that threaten to engulf themselves. Women, who have inhabited many gray zones, present challenges for feminist theorists, who have long struggled with how resistance is possible under coercive institutions. Building on Primo Levi's reflections on the gray zone in Nazi death camps and ghettos, this essay argues that resistance is sometimes possible, although outsiders are rarely, if ever, in a position to judge when. It also raises questions about the adequacy of ordinary moral concepts to mark the distinctions that would be helpful for thinking about how to respond in a gray zone.
Effect of dietary composition on fasting-induced changes in serum thyroid hormones and thyrotropin

Abstract To assess the effect of starvation and refeeding on serum thyroid hormones and thyrotropin (TSH) concentrations, 45 obese subjects were studied after 4 days of fasting and after refeeding with diets of varying composition. All subjects showed an increase in both serum total and free thyroxine (T 4 ), and a decrease in serum total and free triiodothyronine (T 3 ) following fasting. These changes were more striking in men then in women. The serum T 3 declined during fasting even when the subjects were given oral L-T 4 , but not when given oral L-T 3 . After fasting, the serum reverse T 3 (rT 3 ) rose, the serum TSH declined, and the TSH response to thyrotropin-releasing hormone (TRH) was blunted. Refeeding with either a mixed diet ( n = 22) or a carbohydrate diet ( n = 8) caused the fasting-induced changes in serum T 3 , T 4 , rT 3 , and TSH to return to control values. In contrast, refeeding with protein ( n = 6) did not cause an increase in serum T 3 or in serum TSH of fasted subjects, while it did cause a decline in serum rT 3 toward basal value. The present data suggest that: (1) dietary carbohydrate is an important factor in reversing the fall in serum T 3 caused by fasting; (2) production of rT 3 is not as dependent on carbohydrate as that of T 3 ; (3) men show more significant changes in serum thyroid hormone concentrations during fasting than women do, and (4) absorption of T 3 is not altered during fasting.
Negative staining with osmium tetroxide vapour.

NEGATIVE staining has become widely accepted as a means of visualizing macromolecular structures under the electron microscope1,2. Its advantages lie in its simplicity and the high contrast which it offers. Many of the heavy metal salts used as negative stains, however, have not always proved satisfactory because of limited resolution and because of interaction with the specimen. In the course of studying the site of aldehydic groups in tropocollagen we developed a new method of negative staining. This gives delicate outlines of good contrast with macromolecular aggregates that are difficult to visualize with other techniques.
Recurrent HIV-associated immune complex glomerulonephritis with lupus-like features after kidney transplantation.

A spectrum of kidney diseases besides classic human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) exists in HIV-infected patients. Immune complex–mediated glomerulonephritis has emerged as a significant contributor to the burden of kidney disease in this population, particularly in patients of non-African descent. Lupus-like nephritis, a form of immune complex glomerulonephritis with histologic features identical to lupus nephritis in the absence of clinical or serologic markers of lupus, is well recognized as a cause of end-stage renal disease in HIV-infected patients. None of the HIV-associated kidney lesions, whether classic HIVAN or non-HIVAN, has been reported to recur in kidney transplants. We report here for the first time clinical and histologic recurrence of HIV-associated lupus-like nephritis after successful kidney transplantation, causing proteinuria, hematuria, and impaired kidney transplant function.
Spatial and temporal modeling of sub- and supercritical thermal energy storage

Abstract This paper describes a thermodynamic model that simulates the discharge cycle of a single-tank thermal energy storage (TES) system that can operate from the two-phase (liquid–vapor) to supercritical regimes for storage fluid temperatures typical of concentrating solar power plants. State-of-the-art TES design utilizes a two-tank system with molten nitrate salts; one major problem is the high capital cost of the salts ( International Renewable Energy Agency, 2012 ). The alternate approach explored here opens up the use of low-cost fluids by considering operation at higher pressures associated with the two-phase and supercritical regimes. The main challenge to such a system is its high pressures and temperatures which necessitate a relatively high-cost containment vessel that represents a large fraction of the system capital cost. To mitigate this cost, the proposed design utilizes a single-tank TES system, effectively halving the required wall material. A single-tank approach also significantly reduces the complexity of the system in comparison to the two-tank systems, which require expensive pumps and external heat exchangers. A thermodynamic model is used to evaluate system performance; in particular it predicts the volume of tank wall material needed to encapsulate the storage fluid. The transient temperature of the tank is observed to remain hottest at the storage tank exit, which is beneficial to system operation. It is also shown that there is an optimum storage fluid loading that generates a given turbine energy output while minimizing the required tank wall material. Overall, this study explores opportunities to further improve current solar thermal technologies. The proposed single-tank system shows promise for decreasing the cost of thermal energy storage.
Los Alamos National Laboratory Fission Basis

This report is an overview of two main publications that provide a comprehensive review of the Los Alamos National Laboratory (LANL) Fission Basis. The first is the experimental paper, “Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on 239Pu, 235U, 238U,” [Selby, H. D., et al., Nucl. Data Sheets, Vol. 111 2010, pp. 2891–2922] and the second is the theoretical paper, “Fission Product Yields from Fission Spectrum n+239Pu for ENDF/B-VII.1,” [Chadwick, M. B., et al., Nucl. Data Sheets, Vol. 111, 2010, pp. 2923–2964].
Gallium nitrate inhibits alkaline phosphatase activity in a differentiating mesenchymal cell culture

The effect of gallium nitrate on alkaline phosphatase activity in a differentiating chick limb-bud mesenchymal cell culture was monitored in order to gain insight into the observation that rachitic rats treated with gallium nitrate failed to show the expected increase in serum alkaline phosphatase activity. Cultures maintained in media containing 15 microM gallium nitrate showed drastically decreased alkaline phosphatase activities in the absence of significant alterations in total protein synthesis and DNA content. However, addition of 15 microM gallium nitrate to cultures 18 h before assay for alkaline phosphatase activity had little effect. At the light microscopic and electron microscopic level, gallium-treated cultures differed morphologically from gallium-free cultures: with gallium present, there were fewer hypertrophic chondrocytes and cartilage nodules were flatter and further apart. Because of altered morphology, staining with an antibody against chick cartilage alkaline phosphatase appeared less extensive; however, all nodules stained equivalently relative to gallium-free controls. Histochemical staining for alkaline phosphatase activity was negative in gallium-treated cultures, demonstrating that the alkaline phosphatase protein present was not active. The defective alkaline phosphatase activity in cultures maintained in the presence of gallium was also evidenced when cultures were supplemented with the alkaline phosphatase substrate, beta-glycerophosphate (beta GP). The data presented suggest that gallium inhibits alkaline phosphatase activity in this culture system and that gallium causes alterations in the differentiation of mesenchymal cells into hypertrophic chondrocytes.
Alona weinecki Studer on the subantarctic islands, not Alona rectangula Sars (Chydoridae, Cladocera)†

Since Harding in 1967 named the Alona on Signy Island (South Orkneys) Alona rectangula, this binomen has persisted there and has been extended to other island groups in the Scotia Arc. Elsewhere among the subantarctic islands the binomen Alona weinecki has been used, based on a description in 1878 and a redescription in 1914. A detailed redescription of A. rectangula from Norway and Denmark permitted comparison with available populations of A. weinecki from Signy and South Georgia and of the synonymous taxa Alona bukobensis var. subantarctica and Alona subantarctica. The two taxa, although related, are completely different. Alona rectangula sens. str. does not occur on the subantarctic islands at all. Whether the A. weinecki populations on these islands are the same species is presently unknown. Specimens on Kerguelen Island are reported to be larger than those on the Scotia Arc islands, and among the latter populations there are differences in structure of at least the labrum. The islands in the Scotia Arc, except the Falklands, were completely ice covered during the last glacial age, with documented advances and retreats of the glaciers during the Holocene until 2000 b.p. Conditions on at least some other subantarctic islands were probably comparable. If the Cladocera were eliminated by glacier advances, the islands must have been recolonized during the Holocene from a refugic population, possibly in the Falklands. Strong westerly winds and migration of sea birds might have spread the taxon. If the populations are different, however, then the taxa must have survived on their respective islands during the glacial ages. Large populations containing ephippial females and the three instars of males are needed to resolve this uncertainty. Lectotypes of A. rectangula Sars, A. bukobensis var. subantarctica Ekman, and A. subantarctica Ekman have been selected and are on deposit in the Zoological Museums in Oslo and Stockholm.
A brief follow-up rating

Abstract The BFR is presented as an economical method for evaluating post-hospital adjustment in former psychiatric patients. It incorporates areas of post-hospital function which are generally accepted as having social significance and does not emphasize the subject's current level of symptom discomfort. An attempt is made to incorporate information concerning the totality of the subject's adjustment since discharge rather than utilizing information about a single point in time, and to employ reference points relating to premorbid adjustment. The information required for the rating may be collected and scored by personnel at various levels of training. The BFR score correlates significantly with two of Katz's Adjustment Scales: well validated but considerably more complex measures of post-hospital adjustment.
Online fault diagnosis of wireless sensor networks

This paper proposes an adaptive online distributed solution for fault diagnosis in wireless sensor networks (WSNs). Fault diagnosis is achieved by comparing the heartbeat message generated by neighboring nodes and dissemination of decision made at each node. Time redundancy is used to detect the intermittent faults since an intermittent fault will not occur consistently. The diagnosis performance degradation due to intermittent faults in sensing and transient faults in communication is analyzed. A near optimal trade-off between detection latency and number of tests required to detect intermittent faults is obtained. Simulation results are provided and they show that this work performs better, from both time and energy complexity viewpoint.
The fine structural localization of testicular phosphatases in man: the control testis.

Electron microscopic cytochemistry was used to determine the localization of five phosphatase enzymes—glucose-6-phosphatase, inosine diphosphatase, thiamine pyrophosphatase, acid phosphatase, and adenosine triphosphatase—in control human testes. Glucose-6-phosphatase occurred in the endoplasmic reticulum and nuclear envelope of Sertoli cells, Leydig cells and primitive spermatogonia, but was not observed in more advanced spermatogenic cells. The presence of glucose-6-phosphatase activity paralleled the presence of glycogen in spermatogenic cells, i.e., both occurred in type AL and AD spermatogonia but not in type AP or B spermatogonia or in more advanced spermatogenic cells. Inosine diphosphatase activity was found in the endoplasmic reticulum, nuclear envelope, and Golgi complex of Sertoli cells and all spermatogenic cells except late spermatids. Additionally, inosine diphosphatase activity was localized at the junctions between Sertoli cells and late spermatids, but was not associated with any other plasma membrane. Thiamine pyrophosphatase reaction product was found in the Golgi bodies of Sertoli cells and in spermatogenic cells through immature spermatids. Neither inosine diphosphatase nor thiamine pyrophosphatase was observed in the Golgi bodies of spermatids during acrosomal formation. Acid phosphatase activity was found in lysosomes of spermatogonia, spermatocytes, and spermatids, in lysosomes of Leydig cells, and in lysosomes, lipofuscin bodies, and Golgi cisternae of Sertoli cells. It is thought that Sertoli lysosomes play a role in the phagocytosis of degenerating germ cells; however, the role of spermatogenic or Leydig lysosomes is unknown. Adenosine triphosphatase activity occurred at the interfaces between two spermatogonia, and between Sertoli cells and spermatogonia, but was not observed in the spaces between two Sertoli cells, two spermatocytes, two spermatids, or between Sertoli cells and spermatocytes, or between Sertoli cells and spermatids.
Stimulatory and inhibitory regulation of myocardial adenylate cyclase by 5'-guanylyl-imidodiphosphate.

Abstract Particulate and soluble rat myocardial adenylate cyclase enzymes were characterized with respect to their stimulatory and inhibitory regulation by Gpp(NH)p. Gpp(NH)p (60 μM) stimulated Mg 2+ - and Mn 2+ -dependent adenylate cyclase. High concentrations of Gpp(NH)p (600 μM) attenuated the maximal stimulatory response to Gpp(NH)p but only at low cation concentrations. The attenuating effects of 600 μM Gpp(NH)p resulted predominantly from the introduction of a prolonged lag in the kinetics of activation of adenylate cyclase. Steady-state rates of adenylate cyclase activities were similar with either 60 or 600 μM Gpp(NH)p. At any concentration of Gpp(NH)p, the lag was eliminated by Mg ions or isoproterenol. No antihysteretic property for free Mn ions was evident. Forskolin-sensitive particulate adenylate cyclase was not stimulated further by Gpp(NH)p. A 600 μM concentration of Gpp(NH)p inhibited particulate forskolin-sensitive adenylate cyclase at low Mg ion concentrations. In contrast, Gpp(NH)p at 60 μM consistently activated forskolin-sensitive adenylate cyclase after solubilization. The early transient inhibitory properties of 600 μM Gpp(NH)p which resulted in attenuation of adenylate cyclase by 600 μM Gpp(NH)p were diminished by detergent extraction, resulting in only a minor effect of 600 μM Gpp(NH)p to inhibit solubilized adenylate cyclase. These findings indicate that guanine nucleotides exert both stimulatory and inhibitory control upon the myocardial adenylate cyclase enzyme; that solubilization shifts the balance between the stimulatory and inhibitory properties of Gpp(NH)p to allow more dominant expression of the stimulatory response; and that Mg ions critically modify the nature of the myocardial adenylate cyclase response to Gpp(NH)p.
Pathology Resident and Fellow Education in a Time of Disruptive Technologies

The development of disruptive technologies is changing the practice of pathology. Their implementation challenges traditional educational paradigms. Training programs must adapt to these heuristic needs. The dual explosion of new medical knowledge and innovative methodologies adds new practice aspects to the pathologist's areas of expertise. This transformation potentially challenges the traditional core model of training. It raises questions as to how pathology should incorporate future expanding subspecialty needs into educational and practice models. This article examines the impact of these disruptive technologies on resident and fellow education and explores alternative educational and practice models that may better accommodate pathology's future.
Development of a Low-Cost, Rapid-Cycle Hot Embossing System for Microscale Parts

Hot embossing is an effective technology for reproducing micro-scale features in polymeric materials, especially micron scale patterning. The equipment used for hot embossing to date is often research oriented, (intended to be flexible and provide a wide range of processing conditions), and a dedicated equipment industry has yet to develop. This paper details a hot embossing machine design strategy suitable for large-scale manufacturing. The design is motivated by capital cost reduction, right-size machine design, system simplicity, and production flexibility and scalability. Toward this end, a minimal number of components were used, commercially available off-the-shelf components were chosen where possible, system layout was designed to be modular, and system size was scaled for the intended products (in this case microfluidic devices). Innovative design aspects include the use of new ceramic substrate heaters for electrical heating, choice of a moveable heat sink to minimize heat load during the heating cycle, and the careful design of the thermal elements to minimize cycle time. The capital cost and the cost per part produced with this machine are estimated to be an order of magnitude less than currently available options. This design has a minimum cycle time of two minutes, and replicates microstructures within a 25mm by 75mm area.Copyright © 2008 by ASME
Auditory perception of temporal and spectral events in patients with focal left and right cerebral lesions

The auditory perception of temporal and spectral information was studied in subjects with lesions in the temporoparietal region of the left (LH group), or right (RH group) hemisphere (n = 5 in each group) and in five normal controls. The temporal tasks included gap detection and two complex pattern perception tasks in which subjects had to identify the placement of the two closest tones (separated by the shortest interval) within a sequence of six tones. The spectral tasks involved pitch matching and frequency discrimination. The results showed a "double dissociation": (1) the LH group was impaired in their ability to perceive temporal information, but the perception of spectral information was normal, and (2) the RH group was impaired in their ability to perceive spectral information, but the perception of temporal information was normal. The findings are consistent with the notion that temporal processing is a function of left-hemisphere structures and that spectral processing is a function of right-hemisphere structures.
High insulin combined with essential amino acids stimulates skeletal muscle mitochondrial protein synthesis while decreasing insulin sensitivity in healthy humans.

Context: Insulin and essential amino acids (EAAs) regulate skeletal muscle protein synthesis, yet their independent effects on mitochondrial protein synthesis (MiPS) and oxidative function remain to be clearly defined. Objective: The purpose of this study was to determine the effects of high or low insulin with or without EAAs on MiPS. Design: Thirty participants were randomized to 3 groups of 10 each with each participant studied twice. Study groups comprised (1) low and high insulin, (2) low insulin with and without EAAs, and (3) high insulin with and without EAAs. Setting: The study was conducted in an in-patient clinical research unit. Participants: Eligible participants were 18 to 45 years old, had a body mass index of <25 kg/m2, and were free of diseases and medications that might impair mitochondrial function. Intervention: Low (∼6 μU/mL) and high (∼40 μU/mL) insulin levels were maintained by iv insulin infusion during a somatostatin clamp while maintaining euglycemia (4.7–5.2 mM) and replacing GH ...
Organic geochemistry of hard parts: Assessment of isotopic variability and indigeneity

Abstract The indigenous organic fraction of fossils contains exciting information on the evolutionary biology, paleoecology, and taxonomy of organisms which can be deciphered using geochemical techniques. This approach requires an understanding of isotopic variability and an assessment of indigeneity. In addition to assessing isotopic variability among modern organisms, we explore new applications of isotopes and protein separations for assessing the indigeneity of ancient organic fractions that have likely experienced extreme alteration. Small variation in δ15N and δ13C of high molecular weight organic (HMW) material from bones and teeth of an extant Caiman crocodile (Caiman crocodilus, less than 0.5%) indicated that the bones and teeth were formed contemporaneously from similar dietary material. Isotopic values of HMW material from turtles of the family Trionychidae (7.9 to 12% and −23.9 to −21.5% for δ15N and δ13C, respectively), reflect habitat-associated variations in diet. The δ15N and δ13C of the HMW component from fossil teeth of alligators and gavials from clay-rich depositional environments 8.0–13.3%0 and −24.1 to −21.3%0, respectively, were similar to previously reported values for HMW material from bones of extant, high trophic level consumers. In contrast, the δ15N compositions of teeth of ancient alligators from shell pits are conspicuously low (3.9%0) and could be interpreted as evidence of contamination or extreme alteration. The presence of hydroxyproline, however, in one of the shell pit samples suggests that a remnant of the original protein has been retained in the fossil. Isotopic analysis of bulk organic material will provide only a first approximation in understanding paleoecological and taxonomic relationships. Consequently, we offer an alternative approach to assessing indigeneity of the organic fraction through isotopic analysis of amino acids enantiomers from individual protein fractions. To validate this approach data are presented that indicate that isotopic integrity of several amino acids is maintained during all steps of the preparatory procedure. The ability to document geochemical changes in individual proteins as a function of time and depositional environment will provide significant insight into specific mechanisms that occur during diagenesis.
Creativity and Values

ABSTRACT Barron (1997) and Helson (1990) independently have suggested that a central element in all forms of creativity is the desire or goal to be creative, implying creativity as a core value. Based on these assertions and Schwartz's (1992) theory, we tested the prediction that creative individuals will hold a different values system than their less creative counterparts. University students (N = 278) completed the Schwartz Values Survey (Schwartz, 1992), as well as a behaviorally-based self-report measure of creative accomplishments. At separate occasions, 134 of these participants also devised three creative products rated by the consensual assessment method. In keeping with prediction, creative accomplishments and products correlated significantly not only with the self-direction value composite (both including and excluding the individual item creativity), but also universalism and stimulation. Accomplishments and products correlated negatively with the value composites of tradition, security, and p...
The Arnol'd cat: failure of the correspondence principle

Abstract The classical Hamiltonian H = p 2 /2 m + ϵ ( q 2 /2) Σδ [ s -( t / T )] has an integrable mapping of the plane, [ q n +1 , p n +1 ]= [ q n +1 + p n , q n +2 p n ], as its equations of motion. But then by introducing periodic boundary conditions via (mod 1) applied to both q and p variables, the equations of motion become the Arnol'd cat map, [ q n +1 , p n +1 ] = [ q n + p n , q n + 2 p n ], (mod 1), revealing it to be one of the simplest fully chaotic systems which can be derived from a Hamiltonian and analyzed. Consequently, we here quantize the Arnol'd cat and examine its quantum motion for signs of chaos using algorithmic complexity as the litmus. Our analysis reveals that the quantum cat is not chaotic in the deep quantum domain nor does it become chaotic in the classical limit as required by the correspondence principle. We therefore conclude that the correspondence principle, as defined herein, fails for the quantum Arnol'd cat.
Purification and SAXS analysis of the integrin linked kinase, PINCH, parvin (IPP) heterotrimeric complex.

The heterotrimeric protein complex containing the integrin linked kinase (ILK), parvin, and PINCH proteins, termed the IPP complex, is an essential component of focal adhesions, where it interacts with many proteins to mediate signaling from integrin adhesion receptors. Here we conduct a biochemical and structural analysis of the minimal IPP complex, comprising full-length human ILK, the LIM1 domain of PINCH1, and the CH2 domain of α-parvin. We provide a detailed purification protocol for IPP and show that the purified IPP complex is stable and monodisperse in solution. Using small-angle X-ray scattering (SAXS), we also conduct the first structural characterization of IPP, which reveals an elongated shape with dimensions 120×60×40 A. Flexibility analysis using the ensemble optimization method (EOM) is consistent with an IPP complex structure with limited flexibility, raising the possibility that inter-domain interactions exist. However, our studies suggest that the inter-domain linker in ILK is accessible and we detect no inter-domain contacts by gel filtration analysis. This study provides a structural foundation to understand the conformational restraints that govern the IPP complex.
Isoenzymes of pyruvate dehydrogenase phosphatase. DNA-derived amino acid sequences, expression, and regulation.

Pyruvate dehydrogenase phosphatase (PDP) is one of the few mammalian phosphatases residing within the mitochondrial matrix space. It is responsible for dephosphorylation and reactivation of the pyruvate dehydrogenase complex (PDC) and, by this means, is intimately involved in the regulation of utilization of carbohydrate fuels in mammals. PDP is a dimeric enzyme consisting of catalytic and regulatory subunits. The catalytic subunit of PDP is a Mg2+-dependent enzyme homologous to the cytosolic phosphatases of the 2C family. In the present study, we isolated two cDNAs encoding for mitochondrial phosphatases. The first cDNA is highly homologous to the previously identified cDNA encoding for the catalytic subunit of PDP (PDP1). The second cDNA encodes a previously unknown catalytic subunit of PDP (PDP2). The new phosphatase, expressed as the recombinant protein inEscherichia coli, shows strict substrate specificity toward PDC and does not use phosphorylated branched chain α-ketoacid dehydrogenase as substrate. Like PDP1, PDP2 is a Mg2+-dependent enzyme, but its sensitivity to Mg2+ ions is almost 10-fold lower than that of PDP1. In contrast to PDP1, PDP2 is not regulated by Ca2+ ions. Instead, it is sensitive to the biological polyamine spermine, which, in turn, has no effect on the enzymatic activity of PDP1. Western blot analysis of PDP extracted from mitochondria isolated from liver and skeletal muscle revealed that PDP1 is predominantly expressed in mitochondria from skeletal muscle, whereas PDP2 is much more abundant in the liver rather than muscle mitochondria. Both isoenzymes are expressed in mitochondria from 3T3-L1 adipocytes, but the level of expression of PDP2 is considerably higher. These observations are consistent with previous findings on the enzymatic parameters of PDP in adipose tissue. Thus, our results provide the first evidence that there are at least two isoenzymes of PDP in mammals that are different with respect to tissue distribution and kinetic parameters and, therefore, are likely to be different functionally.
Improving renal cell carcinoma classification by automatic region of interest selection

In this paper, we present an improved automated system for classification of pathological image data of renal cell carcinoma. The task of analyzing tissue biopsies, generally performed manually by expert pathologists, is extremely challenging due to the variability in the tissue morphology, the preparation of tissue specimen, and the image acquisition process. Due to the complexity of this task and heterogeneity of patient tissue, this process suffers from inter-observer and intra-observer variability. In continuation of our previous work, which proposed a knowledge-based automated system, we observe that real life clinical biopsy images which contain necrotic regions and glands significantly degrade the classification process. Following the pathologistpsilas technique of focusing on selected region of interest (ROI), we propose a simple ROI selection process which automatically rejects the glands and necrotic regions thereby improving the classification accuracy. We were able to improve the classification accuracy from 90% to 95% on a significantly heterogeneous image data set using our technique.
Comment in Reply

(1972). Comment in Reply. Annals of the Association of American Geographers: Vol. 62, No. 1, pp. 145-146.
CNS primitive neuroectodermal tumors of childhood

Primitive neuroectodermal tumors ( PNET ) of the central nervous system in children are rare, highly malignant, cystic, and sometimes calcific, and hemorrhagic tumors sharply demarcated from adjacent brain. Microscopically they consist of small predominantly undifferentiated dark cells with neuronal, glial, and mesenchymal elements. We have recently diagnosed and treated five children with PNET . We will review their case histories as well as summarize the previous 133 reported cases with reference to presenting complaints, tumor location, neurodiagnostic studies, and the retrospective results of four treatment programs: 1) surgery alone; 2) surgery and radiation therapy; 3) surgery, radiation therapy, and chemotherapy at time of recurrence; and 4) surgery, radiation therapy, and chemotherapy at onset.
Multiresolution and directional filtering techniques for detecting dust storm direction in satellite imagery

This paper presents a new method for finding the direction of a dust storm in satellite images including the 5-band NOAA-AVHRR imagery that were used in our previous work. The previous methods for obtaining the prominent direction of the dust storms involved the combination of edge detectors and local spectral-domain classification techniques applied to subimages/blocks. These approaches produced promising results but have the limitation of not providing consistent results among the subimages that overlap the dust storm region. In this paper, other algorithms like wavelets and state-of-the-art directional filters, based on the contourlet transform, are used to help us determine the direction with more precision and consistency among the relevant subimages. Before applying the directional filtering to the candidate region of the multispectral image, a preprocessing step involves passing the image through a nonsubsampled pyramid selective amplification, this preprocessing step is required in order to enhance the image and improve its directional streaks, in turn, this will help improve the performance of the directional filter to get better and more consistent results. For AVHRR images, our methodology involves applying directional filtering on bands 4 or 5 since these wavelengths highlight the absorption and subsequent emission of thermal radiation by the silicate particles in the dust storms. Directional filtering is applied on these image bands at different angles where energy measurements are computed to find the prominent direction of the dust storm. The presence of a prominent direction in the texture of the candidate region of the dust storm can be used as a verification of its presence in an automated detection system.
Mechanisms of discrimination reversal in pigeons

Abstract Groups of pigeons were trained on a successive discrimination procedure (multiple variable-interval, extinction schedule, with correction in S−), and then exposed to successive reversals, either daily, or less frequently. At asymptote the birds made more than 90 per cent of their responses to S+, and showed good transfer to a ‘learning set’ series. Three factors were involved in discrimination reversal performance: (a) a tendency to respond to only one of the two stimuli presented each day; (b) control of ‘choice’ by food delivery and by procedural cues; (c) a tendency to respond to the prior S+ (negative transfer). Transfer effects showed themselves in two main ways: (a) by impaired performance on the first reversal following manipulations that increased the salience in memory of S+ on a given day, such as a shift to a new pair of stimuli, or a gap (days off) in a series of daily reversals. The new-problem effect was quite robust, but the days-off effect was observed only when other controlling factors were relatively weak; (b) by impaired performance on the first reversal following learning set training interpolated into a series of reversals. Reversal performance seems to represent a balance among a number of controlling factors, and the factors involved may be different for different individuals, even though the final performances appear similar.
Determination of the potential for fundamental- and adjoint-representation sources in SU(2) in three dimensions

Pure SU(2) lattice gauge theory in three dimensions is studied by Monte Carlo simulation with a determination of the potential between fundamental- and adjoint-representation sources as a major goal. A ${32}^{3}$ lattice is used and Wilson loops up to 16 by 16 are measured using a modification to the standard multihit variance reduction which improves the statistics by at least a factor of 3 at $\ensuremath{\beta}=6.0$. The integrated autocorrelation times measured for the loops show a peak for loops of size $\ensuremath{\beta}$ by $\ensuremath{\beta}$. The fundamental- and adjoint-representation potentials are seen to have the same functional form to very high accuracy and their numerical values are in the ratio of their Casimir operators. The string tension is extracted and scaling is seen to within a few percent over a range of couplings which correspond to a factor of 2 change in the glueball mass. Correlated errors have been taken into account in the extraction of the potentials from the Wilson-loop values.
Invited Commentary: A calculation of all possible oligosaccharide isomers both branched and linear yields 1.05 × 1012 structures for a reducing hexasaccharide: the Isomer Barrier to development of single-method saccharide sequencing or synthesis systems

The number of all possible linear and branched isomers of a hexasaccharide was calculated and found to be > 1.05 x 10(12). This large number defines the Isomer Barrier, a persistent technological barrier to the development of a single analytical method for the absolute characterization of carbohydrates, regardless of sample quantity. Because of this isomer barrier, no single method can be employed to determine complete oligosaccharide structure in 100 nmol amounts with the same assurance that can be achieved for 100 pmol amounts with single-procedure Edman peptide or Sanger DNA sequencing methods. Difficulties in the development of facile synthetic schemes for oligosaccharides are also explained by this large number. No current method of chemical or physical analysis has the resolution necessary to distinguish among 10(12) structures having the same mass. Therefore the 'characterization' of a middle-weight oligosaccharide solely by NMR or mass spectrometry necessarily contains a very large margin of error. Greater uncertainty accompanies results performed solely by sequential enzyme degradation followed by gel-permeation chromatography or electrophoresis, as touted by some commercial advertisements. Much of the literature which uses these single methods to 'characterize' complex carbohydrates is, therefore, in question, and journals should beware of publishing structural characterizations unless the authors reveal all alternate possible structures which could result from their analysis.(ABSTRACT TRUNCATED AT 250 WORDS)
Charge Collection in Bipolar Transistors

Charge collection measurements on bipolar test structures have shown the presence of a charge transfer process, that has been referred to as the ion shunt effect. This process had been previously seen in CMOS test structures. The transfer of charge from the emitter to the collector has been demonstrated to be a localized effect requiring that the ion track pass through both the emitter and collector. Measurements performed on transistors with and without a buried oxide layer showed large differences in charge collection.
In Vitro and in Vivo Evaluation of Dihydropyrimidinone C-5 Amides as Potent and Selective α1A Receptor Antagonists for the Treatment of Benign Prostatic Hyperplasia

α1 Adrenergic receptors mediate both vascular and lower urinary tract tone, and α1 receptor antagonists such as terazosin (1b) are used to treat both hypertension and benign prostatic hyperplasia (BPH). Recently, three different subtypes of this receptor have been identified, with the α1A receptor being most prevalent in lower urinary tract tissue. This paper explores 4-aryldihydropyrimidinones attached to an aminopropyl-4-arylpiperidine via a C-5 amide as selective α1A receptor subtype antagonists. In receptor binding assays, these types of compounds generally display Ki values for the α1a receptor subtype <1 nM while being greater than 100-fold selective versus the α1b and α1d receptor subtypes. Many of these compounds were also evaluated in vivo and found to be more potent than terazosin in both a rat model of prostate tone and a dog model of intra-urethral pressure without significantly affecting blood pressure. While many of the compounds tested displayed poor pharmacokinetics, compound 48 was found ...
Studies on the Synthesis of the Fe-S Cluster of Dihydroxy-acid Dehydratase in Escherichia coli Crude Extract ISOLATION OF O-ACETYLSERINE SULFHYDRYLASES A AND B AND β-CYSTATHIONASE BASED ON THEIR ABILITY TO MOBILIZE SULFUR FROM CYSTEINE AND TO PARTICIPATE IN Fe-S CLUSTER SYNTHESIS

The apoprotein of Escherichia coli dihydroxy-acid dehydratase, which contains a catalytically essential [4Fe-4S] cluster in its active form, has been used as a substrate to investigate Fe-S cluster synthesis. The inactive apoprotein could be reactivated in vitro by factors present in the crude extract of E. coli and to a much smaller extent in the presence of Fe3+, S2−, and dithiothreitol. This reactivation occurs as a result of Fe-S cluster synthesis. It is anticipated that the Fe-S cluster synthesis observed in crude extracts in vitro may involve some of the components that participate in Fe-S cluster synthesis in vivo. The origin of the sulfur used to form Fe-S clusters was investigated. Four enzymatic activities in the crude extract of E. coli were found that can provide sulfur for Fe-S cluster synthesis in vitro by mobilizing the sulfur from cysteine. The purification of the proteins responsible for three of these activities is reported in this paper. The three proteins have been identified as O-acetylserine sulfhydrylase A, O-acetylserine sulfhydrylase B, and β-cystathionase. The rate and extent of sulfide mobilization from cysteine in the reaction catalyzed by O-acetylserine sulfhydrylases A and B depend on the presence of nucleophiles that can add to the aminoacrylate formed on the enzyme following the removal of sulfide from cysteine. A new amino acid is formed when the nucleophiles add to the aminoacrylate. Sulfur mobilization by β-cystathionase does not require a nucleophile, and the reaction is a minor variation on the cleavage of β-cystathionine, with pyruvate, ammonia, and sulfide being the products. Once sulfur is mobilized by these enzymes, its efficient use in Fe-S cluster synthesis seems to be affected by the presence of yet unidentified factors present in crude extract. In crude extract and partially purified preparations from E. coli where these factors are present, the rapidity with which Fe-S clusters are formed and the efficiency with which sulfur is used imply an orderly controlled formation of Fe-S clusters that is generally typified by enzymatic reactions.
Cardiac Catheterization through the Internal Jugular Vein in Pediatric Patients: An Alternative to the Usual Femoral Vein Access

The percutaneous femoral vein approach is used routinely for cardiac catheterization in the pediatric age but in some children, it may be impossible as in the case of iliac vein or inferior vena cava thrombosis due to previous cardiac catheterization, or inconvenient as for right ventricular endomyocardial biopsies. In the period between 1982 and 1990, 160 cardiac catheterizations or right ventricular endomyocardial biopsies were performed in 102 children. Patients ranged in age between 2 months and 17 years (mean, 3.8 years) and in weight from 3.2 to 57.3 kg (mean, 14.4 kg). Indications for the internal jugular vein approach were as follows: (1) thrombosis of the inferior vena cava due to previous cardiac catheterization in 42 patients (41 percent); (2) right ventricular endomyocardial biopsy after cardiac transplant in 19 patients (19 percent); (3) control catheterization of the pulmonary arteries following classic or bidirectional cavopulmonary anastomosis in 16 patients (16 percent); (4) superior vena cava obstruction following Mustards procedure in 14 patients (14 percent); (5) failed percutaneous femoral venous approach in six patients (6 percent); and (6) absence of the hepatic segment of the inferior vena cava in four patients (4 percent). The right or left internal jugular vein could be entered in all but three procedures (98 percent). Seventeen patients had more than one procedure through the same internal jugular vein and the vein was found patent in all. A complete right heart cardiac catheterization was performed using this route. Right ventricular endomyocardial biopsy and interventional procedure were performed through this route. Two major complications occurred. A patient developed a central transient ischemic attack and another patient developed a persistent Horner syndrome. Accidental carotid puncture occurred in five patients without consequences. Our data indicate that cardiac catheterization in infants and children can be performed safely through the internal jugular vein, with a high success rate and a low incidence of major complications.
Kinetics and Mechanism of Ethane Oxidation to Acetic Acid on Catalysts Based on Mo−V−Nb Oxides

Kinetic and isotopic studies showed that C−H bond activation in ethane by surfaces essentially saturated with lattice oxygens is the sole kinetically relevant step in ethane oxidation on Mo−V−NbOx mixed oxides. These conclusions are consistent with the dependence of oxidation rates on O2 and C2H6 pressures, with H/D exchange and kinetic isotope effects, and with the preferential initial incorporation of 16O atoms from the oxide lattice into products formed from 18O2−C2H6 mixtures. The precipitation of active components (Mo0.61V0.31Nb0.08Ox) in the presence of colloidal TiO2 led to 10-fold increases in all rate constants (per active component), consistent with higher dispersion of active components resembling in structure and surface reactivity those prevalent in bulk powders. The concurrent presence of PdOx cocatalyst, even as a separate solid, markedly increased all rate constants for oxidation of ethene intermediates and specifically that for ethene oxidation to acetaldehyde molecules, which are rapidly...
Stochastic flow in capillary blood vessels.

The features of the dynamics of capillary blood flow are analyzed and compared with those of the large blood vessels. The physical causes of the constantly varying unsteady flow are attributed to the random statistical distribution of red blood cell sizes, blood vessel geometry, and the multiloop system. The influence of the capillary system topology and compliance are discussed. Among other things, it is shown theoretically that (1), at a branching point of a capillary blood vessel the branch with a faster stream gets most of the red blood cells, thus explaining the extreme nonuniformity in hematocrit distribution in the capillaries, and (2), in a contracting muscle bundle in which capillaries are parallel to the muscle fibers, the percentage reduction of resistance to blood flow is three times the percentage reduction in length of the muscle bundle if active control by sphincter is absent.
Nanomechanical analyses of nanocrystalline Ni using accelerated molecular timesteps

A majority of nanomechanical deformation simulations of nanostructured components such as nanowires or nanocrystalline materials are regularly carried out using the classical molecular dynamics (MD). Due to the fundamental reason that the MD simulations must resolve atomic level vibrations, the microsecond scale nanomechanical deformation cannot be analyzed using MD with resulting disparity in experimental and nanomechanical simulation results. In this investigation a modified Hybrid Monte Carlo (HMC) method that can be used to analyze time-dependent atomistic mechanical deformation at higher timescales than currently possible using MD is established. For the purpose of comparison HMC analyses of a nanocrystalline Ni sample at a strain rate of 109 s–1 with three different timesteps, viz. 2 fs, 4 fs, and 8 fs, are compared with the analyses based on MD simulations at the same strain rate and with a MD timestep of 2 fs. It is found that the HMC simulation with a timestep of 8 fs correctly reproduces defect formation and the stress-strain response observed during MD simulations with an approximate speedup of 4 times in the simulation time. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Ion-assisted processing of optical coatings

Abstract The use of ion guns in evaporation chambers has opened a number of material processing possibilities. While ion-assisted deposition (IAD) is certainly the most widely known, other applications have also appeared such as ion processing of substrates and ion beam polishing (IBP). The first part of this presentation is devoted to the study of IAD as a means of growing dense layers which are less affected by moisture than those grown by conventional evaporation. We have applied this technique to a number of materials to study its effects on microstructure, chemical composition, and crystallinity. As a result, several major subsequent applications of IAD are starting to emerge. The first is illustrated by the ability of IAD to tailor the chemical composition of compounds in order to tune their properties. In particular, we describe the synthesis by reactive IAD of aluminum oxynitride (AION), a compound with composition-dependent refractive indices which we have successfully used to fabricate rugate filters. A second application we are at present developing is the control of the microstructure and the intrinsic stress. Finally a third application of IAD is the fabrication of nitrides which can be grown by thermal evaporation but only when nitrogen ions are available at the surface of the growing film. Other uses of ion beams are ion beam processing of subtrates and IBP. We present some results regarding the increase in roughness observed in ion bombarded substrates such as germanium, ZnSe, and ZnS. Then, we describe IBP as a means of smoothing surfaces. IBP has been developed to polish rough diamond films produced by microwave-assisted chemical vapor deposition. By achieving r.m.s. roughness values below 5 nm we have opened a range of optical applications for diamond-coated silicon.