cssi/SciSciGPT-SciSciNet huggingface dataset:
Decreased gene expression of steroid 5 alpha-reductase 2 in human prostate cancer: Implications for finasteride therapy of prostate carcinoma

BACKGROUND Steroid 5α-reductase 2 (SRD5A2) catalyzes the conversion of testosterone to the more potent androgen, DHT, in the prostate. The therapeutic influence of SRD5A2 inhibitor finasteride on prostate cancer is currently unknown. The direction and extent of changes in SRD5A2 expression in disease tissues is a relevant issue in this regard. METHODS The expression differences of SRD5A2 in tissues representative of normal, benign, and malignant growth in the human prostate were examined in parallel by comparative analysis of relevant microarray gene expression data. Semiquantitative RT-PCR was used to further verify the gene expression differences of SRD5A2. RESULTS Consistently decreased expression of SRD5A2 was observed in 25 prostate cancer samples when compared to 25 matched normal samples and nine BPH samples. Expression differences among these samples for six other genes were presented in parallel as indicators of the direction and extent of expression changes. These additional genes include SRD5A1, Hepsin (overexpressed in prostate cancer), AMACR (overexpressed in prostate cancer), Keratin 8 (epithelial marker), smooth muscle actin (stromal marker), Nell2 (overexpressed in BPH). Semiquantitative RT-PCR verified the expression differences for SRD5A2 in six normal, six BPH, and six prostate cancer samples. CONCLUSIONS Results from this study, combined with those from previous studies, indicate an association of prostate cancer with reduced 5α-reductase enzymatic activity as a result of remarkably decreased expression of the SRD5A2 gene. The implications of this study for finasteride therapy of prostate cancer are discussed. Prostate 57: 134–139, 2003. © 2003 Wiley-Liss, Inc.
Neutron diffraction study of La4LiAuO8: Understanding Au3+ in an oxide environment

Owing to gold's oxophobicity, its oxide chemistry is rather limited, and elevated oxygen pressures are usually required to prepare ternary and quaternary oxide compounds with gold ions. The Au{sup 3+} oxide, La{sub 4}LiAuO{sub 8}, is remarkable both because it can be prepared at ambient pressure in air, and because of its unusual stability toward thermal decomposition and reduction. The structure of La{sub 4}LiAuO{sub 8} was established by Pietzuch et al. using single crystal X-ray diffraction [1]. The compound adopts an ordered modification of the Nd{sub 2}CuO{sub 4} structure, containing two-dimensional sheets in which AuO{sub 4} square planes are separated from one another by LiO{sub 4} square planes. In light of the meager X-ray scattering factors of Li and O, relative to La and Au, we report here a neutron powder diffraction study of La{sub 4}LiAuO{sub 8}, definitively confirming the structure. To our knowledge, this is the first reported neutron diffraction study of any stoichiometric oxide compound of gold. X-N maps, which make use of nuclear positions obtained from Rietveld refinement of time-of-flight neutron diffraction data and electron densities obtained from synchrotron X-ray powder diffraction data, point to the highly covalent nature of the Au-O bonding in La{sub 4}LiAuO{sub 8}. Thismore » is in good agreement with charge densities and Bader charges obtained from full density functional relaxation of the structure.« less
Fuzzy clustering procedure for evaluation and selection of industrial robots

Abstract Industrial robots are increasingly used by many manufacturing firms. The number of robot manufacturers has also increased, with many now offering a wide range of robots. A potential user is faced with many options in both performance and cost. This paper proposes a decision model for the robot selection problem using fuzzy cluster analysis. Unlike most other models for robot selection, this model considers the fact that a robot's performance, as specified by the manufacturer, is often unobtainable in reality. Robots selected by the proposed model become candidates for factory testing to verify manufacturer's specifications. The proposed model is tested on a real data set, and an example is presented.
Short Term Exposure to a Violent Video Game Induces Changes in Frontolimbic Circuitry in Adolescents

Despite evidence of effects of violent video game play on behavior, the underlying neuronal mechanisms involved in these effects remain poorly understood. We report a functional MRI (fMRI) study during two modified Stroop tasks performed immediately after playing a violent or nonviolent video game. Compared with the violent video game group, the nonviolent video game group demonstrated more activation in some regions of the prefrontal cortex during the Counting Stroop task. In contrast to the violent video game group, significantly stronger functional connectivity between left dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) was identified in the nonviolent video game group. During an Emotional Stroop task, the violent video game group showed more activity in the right amygdala and less activation in regions of the medial prefrontal cortex (MPFC). Furthermore, functional connectivity analysis revealed the negative coupling between right amygdala and MPFC in the nonviolent video game group. By contrast, no significant functional connectivity between right amygdala and MPFC was found in the violent video game group. These results suggest differential engagement of neural circuitry in response to short term exposure to a violent video game as compared to a nonviolent video game.
Fabrication of Super-Hydrophobic Microchannels via Strain-Recovery Deformations of Polystyrene and Oxygen Reactive Ion Etch

In this article, we report a simple approach to generate micropillars (whose top portions are covered by sub-micron wrinkles) on the inner surfaces of polystyrene (PS) microchannels, as well as on the top surface of the PS substrate, based on strain-recovery deformations of the PS and oxygen reactive ion etch (ORIE). Using this approach, two types of micropillar-covered microchannels are fabricated. Their widths range from 118 μm to 132 μm, depths vary from 40 μm to 44 μm, and the inclined angles of their sidewalls are from 53° to 64°. The micropillars enable these microchannels to have super-hydrophobic properties. The contact angles observed on the channel-structured surfaces are above 162°, and the tilt angles to make water drops roll off from these channel-structured substrates can be as small as 1°.
The state of the prion.

There is little doubt that the main component of the transmissible agent of spongiform encephalopathies — the prion — is a conformational variant of the ubiquitous host protein PrPC, and that the differing properties of various prion strains are associated with different abnormal conformations of this protein. The precise structure of the prion is not yet known, nor are the mechanisms of infection, conformational conversion and pathogenesis understood.
A precision cranial immobilization system for conformal stereotactic fractionated radiation therapy

PURPOSE: Conformal radiotherapy has been shown to benefit from precision alignment of patient target to therapy beam (1, 6, 13). This work describes an optimized immobilization system for the fractionated treatment of intracranial targets. A study of patient motion demonstrates the high degree of immobilization which is available. METHODS AND MATERIALS: A system using dental fixation and a thermoplastic mask that relocates on a rigid frame is described. The design permits scanning studies using computed tomography (CT) and magnetic resonance imaging (MR), conventional photon radiotherapy, and high precision stereotactic proton radiotherapy to be performed with minimal repositioning variation. Studies of both intratreatment motion and daily setup reliability are performed on patients under treatment for paranasal sinus carcinoma. Multiple radiographs taken during single treatments provide the basis for a three-dimensional (3D) motion analysis. Additionally, studies of orthogonal radiographs used to setup for proton treatments and verification port films from photon treatments are used to establish day to day patient position variation in routine use. RESULTS: Net 3D patient motion during any treatment is measured to be 0.9 +/- 0.4 mm [mean +/- standard deviation (SD)] and rotation about any body axis is 0.14 +/- 0.67 degrees (mean +/- SD). Day-to-day setup accuracy to laser marks is limited to 2.3 mm (mean) systematic error and 1.6 mm (mean) random error. CONCLUSION: We conclude that the most stringent immobilization requirements of 3D conformal radiotherapy adjacent to critical normal structures can be met with a high precision system such as the one described here. Without the use of pretreatment verification, additional developments in machine and couch design are needed to assure that patient repositioning accuracy is comparable to the best level of patient immobility achievable.
Ferroelectric Tungsten Bronze BSKNN Crystals For Photorefractive Applications

Ferroelectric tungsten bronze BSKNN crystals for photorefractive applicationsR.R. Neurgaonkar, W.K. Cory and J.R. OliverRockwell International Science Center, Thousand Oaks, CA 91360AbstractCe -doped tungsten bronze Ba2_xSrxKl_ NayNb5O16 (BSKNN) ferroelectric crystals havebeen grown by the Czochralski technique, yand are found to be of optical quality withexcellent photorefractive properties. Although the BSKNN crystals studied have a tetra-gonal bronze structure at room temperature, their growth habits are different: BSKNN -1grows in a square shape with four well -defined facets, while BSKNN -2 crystals have anoctahedron shape with eight well- defined facets. Ferroelectric and optical measurementsshow these crystals to have strong longitudinal effects similar to perovskite BaTiO3 andexcellent self -pumped phase- conjugate behavior.IntroductionTetragonal tungsten bronze BSKNN is a ferroelectric material with properties similarto BaTiO3, but with a ferroelectric /paraelectric transition occurring at relatively hightemperatures.1 According to the recent work by Rodriguez et a1,2Bao.5Sr1,5K0.5Nao.5Nb5O15 (BSKNN -2) crystals have an excellent potential forphotorefractive and phase- conjugation applications because of the following features:
The use of cell permeabilization for studying the mechanisms of action of angiotensin II in the adrenal cortex and vascular smooth muscle.

AbstractSome applications of the technique of electropermeabilization to the study of the mechanisms of action of angiotensin II in two of its physiological target cells, the adrenal zona glomerulosa and the vascular smooth muscle cell, are described. The technique proved useful for characterizing the second messenger role of inositol 1,4,5-trisphosphate its metabolic pathways and the effect of Ca2+ on steroidogenesis.
Dynamics of the Nash map in the game of Matching Pennies

An iterative procedure for the game of Matching Pennies is examined in which players use Nash's map to respond to mixed strategies of the other players. It is shown that even though the game of Matching Pennies has a unique Nash equilibrium point, the iterative procedure does not lead to convergence to the Nash equilibrium. In fact we find that if the game is played using this iterative procedure then the successive plays of the game will follow an orbit around the equilibrium point. This orbit has period eight and it is the only periodic orbit other than the equilibrium point.
Food ingestion and growth of the diatom-feeding nematode Chromadorita tenuis

Feeding rates and growth of the free-living brackish water nematode Chromadorita tenuis (G. Schneider, 1906) was studied throughout its life cycle. Populations were fed with the pennate diatom Nitzschia palea var debilis (Kutz.) Grunow in the laboratory at 18°C in agar plates based on seawater of 6‰ S. On the average, during the first day after hatching they ingest 1 μg of cell contents, equal to 20 times the body weight, and the body weight increased from 3.6 to 6.9 ng C. During the entire 12.5 d of juvenile life the weight increased 40 times, whereas the weight only doubled during adult life, which is almost entirely devoted to reproduction. Adult virgins are larger than mated females. The large size of adult virgins indicates that about 50% of the gonad energy might be transferred to somatic growth. The size-frequency distribution of adult body lengths of a laboratory grown population as compared to four wild populations shows that the food offered to the laboratory population was of a poor quality.
New combinations and a new name in Syzygium (Myrtaceae) from Madagascar and the Comoro Islands

Acceptance of current generic concepts in Myrtaceae results in the proposal of 14 new combinations and 1 new name in Syzygium Gaertner. Those taxa from Madagascar and Mayotte originally described in Eugenia L. that have terminal inflorescences and calyptrate corollas should be accommodated within Syzygium. Complete synonymy and typification are given for all accepted
X-Ray Diffraction Analyses of the Reactions Between Intact and Powdered Enamel and Several Fluoride Solutions:

The X-ray diffraction patterns of intact enamel treated with various fluoride solutions showed essentially no change in the crystalline structure of hydroxyapatite. The reaction between powdered enamel of various particle size and fluoride solutions showed a predominance of calcium fluoride formation. The substitution of F for OH ions in hydroxyapatite was not detected in the formation of fluorapatite under the experimental conditions.
Sources of Family Violence

This paper suggests a direction for the exploration of the causes of family violence. Explanatory models of family violence were considered in this regard, with the recommendation that a multi-determined model should be considered to ensure the most accurate explanation. We suggest that family violence will be best understood and prevented or alleviated, if a model is used that considers the interaction of structural violence and the personality features of all the family members.
The judgement of absence in neglect

Abstract The usual way of looking at neglect is by investigating how neglect patients fail to detect that something is there. In this study, we look at how neglect patients correctly detect that something is not there. Patients with parietal lesions (11 with and 16 without neglect) and 23 control subjects indicated whether a dot target was or was not present in a geometrical display. While control subjects were consistently (and unexpectedly) faster in the no-dot than in the dot condition, the distinguishing response time pattern of right parietal patients with neglect was not—as one might expect—a relatively longer response time to left vs right targets, but a longer response time to target absence vs presence. This may be due to a serial search or, alternatively, it might result from double-checking for target absence, produced by lowered perceptual confidence. Since this ‘‘wariness’’ about stimulus absence seems to operate in parallel with neglect patients’ denial of the deficit, we conclude that the response time pattern observed in this study could be used as a measure of subjective (un)awareness of neglect.
Integrating Social Work Perspectives and Models with Concepts, Methods and Skills with Other Professions’ Specialized Approaches

In this article, the authors encourage social work practitioners to identify with and adopt distinctive social work perspectives and practice models rather than solely embrace models or approaches developed by and for other professions. We do so because these perspectives are most responsive to our professions’ mission of social justice and social purpose of paying equal attention to people and their environments. For heuristic purposes, we present and illustrate the ecological perspective and life modeled approach. Since no social work model or approach can take into account every type of life stressor, event and condition, we demonstrate how we can borrow and integrate specialized concepts, methods and techniques from other profession’s approaches. The authors identify five characteristics which borrowed content should meet in order to integrate well with social work models. Accordingly, concepts, methods and skills from a few approaches have particular relevance for social work direct practice: Cognitive-Behavioral Therapy; Motivational Interviewing; Narrative Therapy and Solution-Focused Practice. Moreover, the authors present and illustrate the process of borrowing and integrating concepts, methods and skills from other professions to deepen social work practice.
Black Male-Black Female Conflict: Individually Caused and Culturally Nurtured

Who is to blame? Currently, there is no dearth of attention directed to Black male-Black female relationships. Books, magazine articles, academic journal articles, public forums, radio programs, television shows, and everyday conversations have been devoted to Black male-Black female relationships for several years. Despite the fact that the topic has been discussed over the past several decades by some authors (e.g., Frazier, 1939; Drake and Cayton, 1945; Grier and Cobb, 1968), Wallace's Black Macho and the Myth of the Superwoman has been the point of departure for many contemporary discussions of the topic since its publication in 1979. Actually, Wallace's analysis was not so different in content from other analyses of Black male-Black female relationships (e.g., Drake and Cayton's analysis of "lower-class life" in Black Metropolis). But Wallace's analysis was "timely." Coming so soon on the heels of the Black movement in the late 1960s and early 1970s, and, at a time when many Black male-inspired gains for Blacks were disappearing rapidly, the book was explosive. Its theme, too, was provocative. Instead of repeating
Meromorphic Jost functions and asymptotic expansions for Jacobi parameters

We show that the parameters an, bn of a Jacobi matrix have a complete asymptotic expansion $$a_n^2 - 1 = \sum\limits_{k = 1}^{K(R)} {p_k (n)\mu _k^{ - 2n} + O(R^{ - 2n} ),} b_n = \sum\limits_{k = 1}^{K(R)} {p_k (n)\mu _k^{ - 2n + 1} + O(R^{ - 2n} )} $$ , where 1 < |µj| < R for j ⩽ K(R) and all R, if and only if the Jost function, u, written in terms of z (where E = z + z−1) is an entire meromorphic function. We relate the poles of u to the µj’s.
Cryptochromes: Tail-ored for Distinct Functions

Cryptochromes are important components of circadian clocks in both plants and animals. Recent work suggests that the carboxy-terminal tails of these conserved proteins are used in drastically different ways in different organisms.
Outpatient endoscopic Zenker diverticulotomy.

Objectives/Hypothesis: Staple-assisted, endoscopic Zenker diverticulotomy has been shown to decrease both cost of treatment and length of convalescence when compared with the standard open approach. Although the endoscopic technique is generally considered to be safe, the feasibility of outpatient endoscopic Zenker diverticulotomy has never been reported. Study Design: Retrospective cohort study. Methods: All endoscopic Zenker diverticulotomy procedures performed at Oregon Health and Science University (Portland, OR) between 1998 and 2002 were reviewed. The study group was limited to patients whose surgeries were planned on an outpatient basis. Medical charts were reviewed for indications, demographics, operative findings, complications, and resolution of symptoms. Results: Of the 51 patients who underwent endoscopic, staple-assisted Zenker diverticulotomy, 40 were treated with the intent of outpatient management. Thirty-two cases were primary surgeries, and eight cases were revision treatments. The average patient age was 68 years (age range, 35-91 y), and the mean follow-up period was 5.9 months (range, 1-37 mo). Eight (20%) complications were noted in the study group. Intraoperative complications included 3 patients (7.5%) with mucosal disruptions. These patients underwent uneventful suture repair of small hypopharyngeal mucosal tears encountered intraoperatively and were temporarily observed in the hospital. One patient was admitted for postoperative urinary retention and another for fever and tachycardia 48 hours after surgery. One patient sustained a myocardial infarction. The remainder of patients were fed immediately and discharged home on the day of surgery. Two patients (5%) had iatrogenic tooth fracture. Conclusion: Appropriately selected patients undergoing endoscopic, staple-assisted Zenker diverticulotomy can be managed safely on an outpatient basis. Intraoperative complications, such as a mucosal disruption, warrant conversion to inpatient monitoring.
Further observations on correcting behaviour in boxelder bugs

Abstract 1. 1. After making a forced turn on a causeway, boxelder bugs make a turn on a platform in a direction opposite to the forced turn. The angle turned on the platform increases abruptly or in sigmoid fashion as the start to forced turn distance increases. Blinded bugs show a similar effect, but the angle is reduced and the increase is not sigmoid or abrupt. 2. 2. After running for most of the distance between start and forced turn, bugs can be delayed for 40 seconds or more without effect on mean angle turned on the platform. 3. 3. At a certain critical forced turn angle, between 60 ° and 75 °, the frequency of turns at a choice point offering either a turn opposite to the forced turn or a straight path markedly increases (with the start to forced turn and forced turn to choice point distances kept constant). 4. 4. If bugs were made to circle on a causeway, they would turn opposite to the direction of circling upon arrival at a platform. The amount of turn increased as distance run increased or as the radius of the circling arc decreased. Two important factors thus seem to be distance travelled and rate of change of direction. 5. 5. Blinding reduces the degree of opposite turning made at a choice point after making an abrupt forced turn and the opposite direction turned on a platform after traversing a circling arc. Opposite turning is, however, still present to some extent. It is the lower halves of the eyes which are important. 6. 6. Explanations of the above behaviour based on “centrifugal swing” and “reactive inhibition” are rejected. 7. 7. Events occurring at the forced turn probably interact with an excitatory state built up between the start and the forced turn to cause opposite turning at a choice point. Whatever the excitation state, it builds up in sigmoid or abrupt fashion and endures for a period of at least 40 seconds. 8. 8. Vision certainly, and proprioception probably, are important factors in the performance of the above behaviour.
On the remarkable structure of the superconducting intermediate state

Abstract If a large square plate of a type I superconductor is placed in a perpendicular magnetic field, the field will penetrate it in a pattern of domains. The intermediate-state problem is to predict this pattern. In the critical Ginzburg-Landau theory, the horizontal and momentum directions of the plate are essentially Fourier conjugate coordinates, like position and momentum in quantum mechanics. Thus, the intermediate state allows us a rare direct glimpse of quantum phase space. It is also demonstrated that, although Landau's (1937) textbook model is inconsistent with the Ginzburg-Landau equations, its qualitative nature is correct. Elongated structures consistent with a complete spontaneous breakdown of discrete rotational invariance are predicted. Comments with regard to lattice Higgs simulations are also made.
Severe preeclampsia at <25 weeks of gestation: maternal and neonatal outcomes.

Abstract Objective: The purpose of this study was to determine maternal and neonatal outcomes of women who were delivered because of severe preeclampsia before 25 weeks of gestation. Study design: We used a computerized database to identify 3800 women with preeclampsia among 35,937 deliveries from 1991 to 1997. Of these, 39 women (1%) with severe preeclampsia were delivered before 25 weeks of gestation. We abstracted outcomes in these women and their newborns. Results: All 39 women had severe preeclampsia as defined by clinical and/or laboratory criteria. Thirty-three of the 39 women had severe-range hypertension. Twenty-one women (54%) experienced morbidity that included abruptio placentae (n = 5), HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome (n = 9), renal insufficiency (n = 5), and eclampsia (n = 3). No women required dialysis or intensive care unit admission, and none of the women died. All maternal morbidities reversed after delivery. Twenty-two infants (55%) were live-born. Only 4 infants (10%) survived, all with severe handicaps. Conclusion: In women with severe preeclampsia before 25 weeks of gestation, delivery is associated with minimal short-term maternal morbidities, although neonatal morbidity and death are appreciable. (Am J Obstet Gynecol 2002;186:790-5.)
Center‐Based Early Childhood Education and Care in China: Policies, Trends, and Implications

The development of early childhood education and care (ECEC) policies and programs in China has been closely intertwined with social, economic, and demographic changes. This article systematically reviews center-based ECEC policies and programs in China and presents the major trends and implications for future research and policy. The focus of China’s ECEC policy has shifted from health and custodial care to nurturing and child-centered education since the economic reforms and the one-child policy were launched in the late 1970s. Empirical data show that the costs of ECEC services have been continuously increasing. Both the number of children enrolled and the overall enrolment rates have declined during the late 1990s but they have increased slightly since 2001. The ECEC programs vary substantially in every regard by urban or rural residence, type of organization, and region. The quality of center-based ECEC programs in China is still quite low, indicated by their high child–teacher ratios and low levels of education among principals and teachers relative to developed countries. Children living in rural areas or less developed regions and those from low-income families suffer from fewer resources and lower quality ECEC as compared to their peers. These problems must be addressed by future policy interventions.
Afferent Drive of Medial Prefrontal Cortex by Hippocampus and Amygdala is Altered in MAM-Treated Rats: Evidence for Interneuron Dysfunction

Evidence indicates that the prefrontal cortex and its regulation by afferent inputs are disrupted in schizophrenia. Using a validated rat model of schizophrenia based on prenatal administration of the mitotoxin methyl azoxymethanol acetate (MAM), we examined the convergent projections from the ventral hippocampus (vHipp) and the basolateral amygdala (BLA) in the medial prefrontal cortex (mPFC). In vivo extracellular recordings were done in anesthetized rats to assess how prior stimulation of the BLA or vHipp input to the mPFC affected mPFC responses to subsequent stimulation of these regions. The interstimulus interval (ISI) of the BLA and vHipp pulse stimulation was varied randomly between 0 and 130 ms, and the probability of evoked spike response in the mPFC measured. We found that BLA input increased vHipp-evoked spike probability at ISIs 40–130 ms, but decreased spike probability at ISIs 10–20 ms. This would be consistent with activation of inhibitory interneurons at shorter ISIs by BLA stimulation. In contrast, in MAM-treated rats BLA stimulation increased vHipp-evoked spike probability in mPFC at all ISIs tested. Given that interneurons are driven primarily by N-methyl-D-aspartate (NMDA) channel activation, the effects of the NMDA channel blocker, phencyclidine (PCP), were tested. PCP was found to completely attenuate the inhibitory effect of BLA input on vHipp-evoked responses in mPFC at shorter ISIs, causing the response in control rats treated with PCP to resemble that observed in the MAM rat. In contrast to the effects of BLA stimulation on vHipp-mPFC-evoked responses, there was no inhibitory period when examining the effects of vHipp stimulation on BLA-mPFC-evoked responses in control rats, but in MAM-treated rats there was a significant inhibition at short intervals. Thus, both affective input arising from the BLA and context-dependent input from the vHipp exert a modulatory effect on mPFC neural activity in response to these inputs. Whereas the BLA potentiated vHipp input to the mPFC at long intervals, there was a short-interval inhibitory period that appeared to be mediated by an NMDA-dependent drive of interneurons. This inhibitory modulation was absent in the model of schizophrenia and following PCP, which is consistent with an interneuron disruption in this disorder.
Light driven scattering changes and increased 515 nm absorbance changes associated with fatty acid inhibition of photosynthesis in Chlorella.

Abstract 1. The size and time of half decay of the 515 nm positive and 475 nm negative light driven absorbance changes in Chlorella was considerably increased by 1 · 10−4–5 · 10−4 M lipoic, caprylic and iodoacetic acids and by 1 · 10−5–8 · 10−5 M nitrous acid. Salts of these acids at neutral pH, iodoacetamide and HCl did not affect the absorbance changes. 2. The absorbance changes were restored to their original size and photosynthetic CO2 fixation partially restored on washing the cells free of lipoic acid. 3. Light driven absorbance changes at 350 nm (positive), 405 nm, 425 nm, 450 nm and 648 nm (all negative) were unchanged in magnitude on addition of acid but their decays were slowed. The greater part of the 515-475 nm changes is therefore not due to Chlorophyll b. 4. Addition of 10−3 M caprylic, lipoic, iodoacetic acids, methyl octonoate and hexyl resorcinol caused slow reversible light driven scattering changes which were not associated with volume changes of the whole cell.
A review of recent field tests and mathematical modelling of atmospheric dispersion of large spills of Denser-than-air gases

Large-scale spills of hazardous materials often produce gas clouds which are denser than air. The dominant physical processes which occur during dense-gas dispersion are very different from those recognized for trace gas releases in the atmosphere. Most important among these processes are stable stratification and gravity flow. Dense-gas flows displace the ambient atmospheric flow and modify ambient turbulent mixing. Thermodynamic and chemical reactions can also contribute to dense-gas effects. Some materials flash to aerosol and vapor when released and the aerosol can remain airborne, evaporating as it moves downwind, causing the cloud to remain cold and dense for long distances downwind. Dense-gas dispersion models, which include phase change and terrain effects have been developed and are capable of simulating many possible accidental releases. A number of large-scale field tests with hazardous materials such as liquefied natural gas (LNG), ammonia (NH3), hydrofluoric acid(HF) and nitrogen tetroxide(N2O4) have been performed and used to evaluate models. The tests have shown that gas concentrations up to ten times higher than those predicted by trace gas models can occur due to aerosols and other dense-gas effects. A methodology for model evaluation has been developed which is based on the important physical characteristics of dense-gas releases.
A Digital Parameter-Identification Technique Applied to Biological Signals

A numerical procedure that shows promise as a parameter-identifying scheme is presented. The procedure is simple enough to allow real-time analysis on a small high-speed computer. Results of application to simulated and real blood-pressure curves are presented and discussed.
Intra-individual and inter individual variations in plasma free amino acids in normal adults.

Summary Over periods of several months three serial determinations of plasma free amino acids have been performed in each of 14 individuals. Large intra-individual variations in levels of most of these amino acids were observed. Since normal values for each plasma free amino acid may vary as much as twofold or more among individuals, any study of plasma free amino acids in groups of patients must encompass a large population sample, unless profound differences from normal exist. Other considerations in experimental design of a study of this type have been discussed. Although the concept of biochemical individuality holds for all the amino acids except lysine and phenylalanine, it is diluted in importance by the large intra-individual variations observed.
YBa2Cu3O6 + x synthesis using vertical self-propagating high-temperature synthesis

Abstract YBaCu 3 O 6+ x superconductor powders were produced by a modified vertical self-propagating high-temperature synthesis (SHS) from yttrium oxide, barium peroxide, and copper at room temperature. A 90 mm diameter, 14 cm long cylinder of reactants was converted to 2 kg of YBa 2 Cu 3 O 6+ x superconductor in less than 3 min. The oxygen-flow rate and pellet diameter had an important impact on the product concentrtion distribution inside the pellet. Several post-treatment procedures may be used to improve the product quality. Optimal conditions for each procedure were determined. Internal pellet-temperature measurements showed that the reaction proceeds in two steps. In the initial stage, copper is oxidized and forms BaCuO 2 . In the second stage, Y 2 O 3 dissolves in melted BaCuO 2 , forming YB 2 Cu 3 O 6.5 , which absorbs oxygen during the cooling period to form superconducting YBa 2 Cu 3 O 6+ x .
Dark Matter and Pulsar Origins of the Rising Cosmic Ray Positron Fraction in Light of New Data From AMS

The rise of the cosmic ray positron fraction with energy, as first observed with high confidence by PAMELA, implies that a large flux of high energy positrons has been recently (or is being currently) injected into the local volume of the Milky Way. With the new and much more precise measurement of the positron fraction recently provided by AMS, we revisit the question of the origin of these high energy positrons. We find that while some dark matter models (annihilating directly to electrons or muons) no longer appear to be capable of accommodating these data, other models in which ∼1-3 TeV dark matter particles annihilate to unstable intermediate states could still be responsible for the observed signal. Nearby pulsars also remain capable of explaining the observed positron fraction. Future measurements of the positron fraction by AMS (using a larger data set), combined with their anticipated measurements of various cosmic ray secondary-to-primary ratios, may enable us to further discriminate between these remaining scenarios.
Enhancement of ultraviolet disinfection of wastewater by high pressure water jet pretreatment: preliminary results and a new approach.

The shield or shadow effect of large particles on bacteria undergoing irradiation from ultraviolet light in effluent of treated wastewater would greatly reduce the effectiveness of ultraviolet disinfection. The objective of this work is to evaluate the newly proposed method of applying a high pressure water jet (HPWJ) as a pretreatment step in combination with ultraviolet irradiation to improve the disinfection efficiency of wastewater by breaking up the large particles (reducing the shield or shadow effects). Pretreatment experiments with two HPWJ units having different water pressure output (6.9 and 13.1 MPa) and nozzles were conducted in the study on primary clarifier overflow (PCO). The experiment results revealed that the particle size distributions (PSDs) in the test samples were apparently shifted toward the small size range and the total number of particles has been greatly increased after undergoing treatment with the HPWJ. In general it is assumed that bioparticles larger than a certain size ( 1...
Guanidinato complexes of iridium: ligand-donor strength, O2 reactivity, and (alkene)peroxoiridium(III) intermediates.

A series of seven [Ir{ArNC(NR2)NAr}(cod)] complexes (1a–1g; where R = Me or Et; Ar = Ph, 4-MeC6H4, 4-MeOC6H4, 2,6-Me2C6H3, or 2,6-iPr2C6H3; and cod = 1,5-cyclooctadiene) were synthesized by two different methods from the neutral guanidines, ArN═C(NR2)NHAr, using either MeLi and [{Ir(cod)}2(μ-Cl)2] or [{Ir(cod)}2(μ-OMe)2]. Reaction of 1a–1g with CO produced the corresponding [Ir{ArNC(NR2)NAr}(CO)2] complexes (2a–2g), which were characterized by NMR and solution- and solid-state IR spectroscopy. Complexes 1b (R = Et, Ar = Ph), 1d (R = Et, Ar = 4-MeC6H4), 1f (R = Me, Ar = 2,6-Me2C6H3), and 2b (R = Et, Ar = Ph) were characterized by X-ray crystallography as mononuclear complexes with a guanidinato-κ2N,N′ ligand and a cod or two CO ligands coordinated to the Ir center in a distorted square-planar environment. On the basis of the CO stretching frequencies of 2a–2g [avg. νCO (n-pentane) = 2016–2019 cm–1] and the alkene 13C chemical shifts of 1a–1g [δ(13CC═C) = 58.7–61.0 ppm], the donor strength of the guanidinat...
Sedimentation field flow fractionation of fused unilamellar vesicles: Comparison with electron microscopy and gel filtration

Sedimentation field flow fractionation (SF3), a relatively new instrumentation methodology for separating particles according to size, has been used to monitor changes in vesicle size during the formation of fused unilamellar vesicles of dipalmitoylphosphatidylcholine. The fusion of 500-A small unilamellar vesicles to 700-A large unilamellar vesicles (LUVs) and the slower conversion to 950-A LUVs at 4 degrees C was readily monitored by SF3 over the time course of a month. Changes in the physical state of these vesicles as a result of structural reorganizations were characterized by high sensitivity differential scanning calorimetry. The advantages and limitations of SF3 are discussed and correlated with electron microscopy and gel filtration.
Oscillatory Combustion of Fine-AP/HTPB Propellants: Disproportionate Pyrolysis Response

The combustion of hydroxyl-terminated polybutadiene (HTPB)propellants containing e neammonium perchlorate (AP) was investigated using laser-excited, combustion recoil at 1 ‐5 atm. At 1 atm, binder-rich (70‐75% AP), monomodal e ne-AP (2‐50 µm) propellants exhibit a prominent non-quasi-steady gas and surface reaction zone, homogeneous propellant, one-dimensional e ame response peak at 100 ‐300 Hz, with frequency varying inversely with AP size. Adding coarse AP (resulting in a wide, bimodal AP distribution ) causes this response to disappear at 1 atm. Raising the pressure to 2 atm causes the response to reappear and increase in frequency to 600 ‐800 Hz (2-µm AP). This oscillatory combustion behavior is attributed to time-varying selective or disproportionate pyrolysis of AP and HTPB (unsteady accumulation and depletion of AP at the propellant surface ) and the associated compositional (stoichiometric ) e uctuations that occur in the fuel-rich, premixed gas-phase reaction zone adjacent to the e ne-AP/HTPB solid region. A low Peclet number appears to be a requirement of achieving this condition. Combustion recoil and thermocouple measurements at 1 atm without laser excitation exhibited spontaneous oscillations in the monomodal e ne-AP propellants and corroboratethe disproportionate pyrolysis interpretation of the laser-excitedresonant response. This e nding of a strong disproportionationresponsein compositepropellants with e ne AP or binder-rich, e ne-AP matrix regions has important implications for pressure-coupled response and solid rocket motor stability in that the same response mechanism could operate under oscillatory pressure conditions and at elevated pressures.
Phase transformations in XDTM TiB2-reinforced near-γ Ti48Al2Nb2Mn

Abstract The elevated temperature phase transformations occurring in investment cast and hot-isostatically pressed near-gamma Ti 48Al 2Nb 2Mn containing 0, 0.5, 1, 2 and 7 vol.% TiB 2 have been investigated utilizing in situ thermal analysis, high temperature X-rays and optical and transmission electron microscopies. A series of reversible transformations were observed during heating and cooling:α 2 + γ → α + γ → α + β + γ → β + γ → β +L where, on heating, the low temperature eutectoid transformationα 2 + γ→α was followed by β precipitation and γ dissolution, a high temperature reverse peritectoid reaction,→αβ + γ, and, finally, an inverse peritectic reaction,γ→β+ L. Furthermore, the variable TiB 2 morphologies observed suggest that TiB 2 redissolves during XD TM processing, reprecipitating during subsequent solidification. Its morphology then evolves from lacey to plate- or needle-like, to blocky as the B content increases or the solidification rate decreases. Finally, it was shown that, rather thatn the TiB 2 content per se , the elemental B content and, by extension, the total interstitial content were the primary factors controlling the differences in the phase transitions temperatures observed in these materials. As the interstitial content increased, the eutectoid transformation temperature increased, while the peritectoid transformation temperature was not affected and the peritectic transformation temperature decreased.
Microbially mediated nitrogen retention and loss in a salt marsh soil

Salt marshes currently play an important role as filters for upslope nitrogen (N) inputs. This could change in the future with sea level rise, warming and eutrophication, which are expected to favor monocultures over diverse plant communities. We explored patterns in gross N cycling, dissimilatory nitrate (NO3−) reduction to ammonium (NH4+) (DNRA), and denitrification in a salt marsh soil under two typical redox conditions (aerobic and anaerobic), and in soils under plant communities manipulated to simulate potential future composition (forb and graminoid monocultures). Natural salt marsh soils exhibited high potential gross N mineralization rates, averaging 50.4 ± 5.7 μg N g−1 d−1 under aerobic conditions; rates declined to 23.6 ± 3.4 μg N g−1 d−1 under an N2 headspace. Microbial NH4+ uptake and gross nitrification together accounted for only 14 % of gross N mineralization. Nitrogen retention via DNRA and microbial uptake greatly exceeded N losses via denitrification. Gross nitrification rates were great...
Development of solid state light sources based on II-VI semiconductor quantum dots

Solid state light sources based on integrating commercial near-UV LED chips with encapsulated CdS quantum dots are demonstrated. Blue, blue-green, and white quantum dot LEDs were fabricated with luminous efficiencies of 9.8, 16.6, and 3.5 lm/W, respectively. These are the highest efficiencies reported for quantum dot LEDs. Quantum dots have advantages over conventional micron-sized phosphors for solid state lighting, such as strong absorption of near-UV to blue wavelengths, smaller Stokes shift, and a range of emission colors based on their size and surface chemistry. Alkylthiol-stabilized CdS quantum dots in tetrahydrofuran solvent with quantum yields (QYs) up to 70% were synthesized using room temperature metathesis reactions. A variety of emission colors and a white spectrum from monodisperse CdS quantum dots (D~2 nm) have been demonstrated. The white emission was obtained from the CdS quantum dots directly, by altering the surface chemistry. When incorporated into an epoxy, the high solution phase QY was preserved. In contrast to other approaches, the white LED contains monodisperse CdS quantum dots, rather than a blend of different-size blue, green, and red-emitting quantum dots. The concentration of CdS quantum dots in epoxy can be increased to absorb nearly all of the incident near-UV light of the LED.
A time-coordination approach for compensating pulse-load using flywheel

The concept of regenerative energy management in dual-ac-dc grids in presence of pulse-load is investigated in this paper. The results of this work are applicable to dual ac-dc micro-grids with flywheel (FW) energy storage systems. Undesirable impacts of the pulse-load, on the dual system, are mitigated through both the proposed system configuration, and time-coordination between the occurrence of pulse-loads and the release of kinetic energy from the flywheel. The obtained results are validated through experiments.
Combinatorial Problems: Reductibility and Approximation

Recent research in the theory of algorithms has determined that many classical operations research problems are computationally related; i.e., an efficient algorithm for one implies the existence of efficient algorithms for everyone or a proof that one is inherently difficult implies they are all so. This paper presents a tutorial of this concept. In contrast to other surveys it does so by selecting a few problems knapsack, traveling salesperson, multiprocessor scheduling, and flow shop and carefully shows how they are related. References to most other problems of interest to operations researchers are given. The second part of this paper is a survey on the relatively recent progress in the study of approximation algorithms. These algorithms hold great promise for they work fast and in many cases are guaranteed to work well. Again the techniques for devising and analyzing these algorithms are explained through the continued use of these examples.
Peripheral neuropathy and object length perception by effortful (dynamic) touch: a case study.

The spatial extents of hand-held objects can be perceived nonvisually by wielding them. This ability of effortful or dynamic touch to exploit the mass moments of an object to perceive its length was evaluated with a 40-years old right-handed woman with surgically treated Arnold-Chiari Type 1 Malformation and cervical syrinx. At the time of the experiment she presented with loss of discriminative touch in the left arm but no comparable sensory deficits in the right arm or the lower extremities. She could neither identify objects in her left hand nor tell that they were in the hand while manipulating them. She could, however, grasp an object tightly and wield it on request. In the experiment she wielded weighted rods of 45, 60, and 80 cm length about the wrist. There were two main results. First, her nonvisual perception of rod length by the insensate left arm scaled systematically with rod moment of inertia. The scaling matched that of the intact right arm and the nondominant arm of haptically unimpaired controls tested with rods of similar dimensions. Second, her right arm was superior in accuracy and reliability than her insensate left arm and was equal to or better than the dominant arm of the control group on key measures of nonvisual length perception. The first result was evaluated in respect to the notions of numb touch and differences in the neural bases of discriminative and effortful touch. The second result was discussed in terms of contralateral cortical enhancement by deafferentation.
Adapting to a Declining Environment: Lessons from a Religious Order

This study examines the ten U.S. provinces of the largest religious order of Catholic priests and brothers, the Jesuits, and explores the structural/organizational adaptations which these ten provinces employed to accommodate dramatic reductions in membership. The organizational placement of roughly 11,000 individual members of these provinces is traced between the years 1965 and 1979. The research indicates that, by increasing interorganizational cooperation and exchange of information and by enhancing the administrative component, these organizations were able to reduce slack resource requirements and were largely able to protect their core operations from the impact of decline. These observations differ dramatically from those reported in typical, for-profit organizations e.g., Harrigan 1980. Finally, to the extent that cutback did reach the core, an attempt is made to examine the width and depth of retrenchment at both the divisional and departmental levels and to determine whether the mode of retrenchment affected individuals' willingness to subsequently invest in the organization. The analysis suggests that narrower, deeper cuts at the departmental level may have had a positive effect on members' willingness to invest in the organizations, while narrower, deeper cuts at the division level may have contributed to more members deciding to leave the organizations.