cssi/SciSciGPT-SciSciNet huggingface dataset:
Heterokaryotic nuclear conditions and a heterogeneous nuclear population are observed by flow cytometry in Phytophthora infestans

A simple and reliable method for preparation of whole nuclei of a common oomycete, Phytophthora infestans, is described for laser flow cytometry. The ease of preparation, the absence of detectable debris and aggregates, and the precision in determinations of DNA content per nucleus improve interpretation and understanding of the genetics of the organism. Phytophthora infestans is the pathogen that causes potato and tomato late blight. The genetic flexibility of P. infestans and other oomycete pathogens has complicated understanding of the mechanisms of variation contributing to shifts in race structure and virulence profiles on important agricultural crops. Significant phenotypic and genotypic changes are being reported in the apparent absence of sexual recombination in the field. Laser flow cytometry with propidium iodide is useful in investigating the nuclear condition of the somatic colony of field strains of P. infestans. The majority of the studied strains contain a single population of nuclei in nonreplicated diplophase. However, mean DNA content per nucleus varies considerably among isolates confirming the heterogeneity of the nuclear population in regard to C-value, for field isolates. Nuclear DNA content varies from 1.75x to 0.75x that of nuclei in a standard strain from central Mexico. Some strains contain two to three populations of nuclei with differing DNA contents in the mycelium and are heterokaryons. Such a range in DNA content suggests DNA-aneuploidy, but direct confirmation of aneuploidy will require microscopy of chromosomes. Heterokaryosis and populations of nuclei of differing DNA content necessarily confound standardized assays used worldwide in crop breeding programs for determination of race profiles and virulence phenotypes of this important pathogen.
Heat flow and subsurface temperature as evidence for basin-scale ground-water flow, North Slope of Alaska

In conjunction with the U.S. Geological Survey's exploration program in the National Petroleum Reserve, Alaska (NPRA) several high-resolution temperature logs were made in each of 21 drillholes between 1977 and 1984. These time-series of shallow (average 600-m depth) temperature profiles were extrapolated to infinite time to yield equilibrium temperature profiles (±0.1 °C). Thermal gradients are inversely correlated with elevation, and vary from 22 °C/km in the foothills of the Brooks Range to as high as 53 °C/km on the coastal plain to the north. Shallow temperature data were supplemented with 24 equilibrium temperatures (±3-5 °C) estimated from series of bottom-hole temperatures (BHTs) measured near the bottom of petroleum exploration wells. A total of 601 thermal conductivity measurements were made on drill cuttings and cores. Near-surface heat flow (±20%) is inversely correlated with elevation and ranges from a low of 27 mW/m2 in the foothills of the Brooks Range in the south, to a high of 90 mW/m2 near the north coast. Subsurface temperatures and thermal gradients estimated from corrected BHTs are similarly much higher on the coastal plain than in the foothills province to the south. Significant east-west variation in heat flow and subsurface temperature is also observed; higher heat flow and temperature coincide with higher basement topography. The observed thermal pattern is consistent with forced convection by a topographically driven ground-water flow system; alternative explanations are largely unsatisfactory. Average ground-water (Darcy) velocity in the postulated flow system is estimated to be of the order of 0.1 m/yr; the effective basin-scale permeability is estimated to be of the order of 10-14 m2. Organic maturation data collected in other studies indicate that systematic variations in thermal state may have persisted for tens of millions of years. The ground-water flow system thought to be responsible for present heat-flow variations conceivably has existed for the same period of time, possibly providing the driving mechanism for petroleum migration and accumulation at Prudhoe Bay.
A Distribution Function for the Particles in an Anisotropic Relativistic Plasma

The particles making up a plasma are usually not in equilibrium, and their energies are often relativistic and anisotropically distributed, especially if the plasma is in a d.c. magnetic field. Thus, the usual methods for developing particle distribution functions based on equilibrium conditions are not applicable. A development of a particular anisotropic relativistic distribution function that may describe the particles in a plasma is made.
Real-time observations of ultra-thin iron oxide film growth on oxygen-deficient YSZ(001)

Abstract We use low energy electron microscopy (LEEM) and low energy electron diffraction (LEED) to characterize the initial stages of iron oxide film growth on oxygen-deficient YSZ(001). The films are grown by Fe deposition in a background of 10− 6 to 10− 5 Torr O2. The first layer grows as FeO(111) with four non-equivalent domains arising from two rotational orientations and two stacking sequences. Uniform spreading of 2-D islands is observed by initiating growth at ~ 1000 °C and raising the temperature to 1110–1145 °C during Fe deposition. The growth is anisotropic with the fast growth direction depending strongly on both the rotational and stacking domain structure, most likely the result of preferred O2 dissociation at specific island edge configurations. The FeO(111) film has a distinct LEEM-IV spectrum with three well-defined maxima and is easily distinguished from the YSZ(001) substrate. The coarsening of small islands (
Enterprise risk management: A systems-thinking framework for the event identification phase

Abstract Guidelines for developing and implementing a program of enterprise risk management have been developed by the Committee on Sponsoring Organizations of the Treadway Commission. One component of this risk management program is event identification, which involves developing a list of events that could affect the ability of the enterprise to meet its strategic and operating objectives. The guidelines establish objectives for event identification and suggest general procedures for identifying events that represent business risks. In this paper, I describe how systems-thinking could provide a framework to identify events that should be considered during risk assessment by (a) creating a map of the organization's value chain that specifies relationships among the atomic components of the business model, and (b) using a taxonomy of categories to analyze those relationships and identify events that could threaten business process performance.
Identification of bound nitro musk-protein adducts in fish liver by gas chromatography-mass spectrometry: biotransformation, dose-response and toxicokinetics of nitro musk metabolites protein adducts in trout liver as biomarkers of exposure.

Abstract Ubiquitous occurrences of synthetic nitro musks are evident in the literature. The in vivo analysis of musk xylene (MX) and musk ketone (MK)-protein adducts in trout liver has been performed by gas chromatography–mass spectrometry using selected ion monitoring (GC–SIM-MS). Biotransformation, dose–response and toxicokinetics studies of 2-amino-MX (2-AMX), 2-amino-MK (2-AMK) and 4-amino-MX (4-AMX) metabolites, covalently bound to cysteine amino acids in proteins in fish liver, formed by enzymatic nitro-reduction of MX and MK, have been described. Trouts were exposed to single exposures of 0.010, 0.030, 0.10, and 0.30 mg/g MX and/or MK. Forty-two fish liver samples were collected from exposed- and control-fish subsequent to exposure intervals of 1 day, 3 days, and 7 days and were composited as per exposure schedules and times. Alkaline hydrolysis released bound metabolites from exposed liver composites that were extracted into n -hexane and then concentrated and analyzed by GC–SIM-MS. The presence of the metabolites in liver extracts was confirmed based on agreement of similar mass spectral properties and retention times with standards. In the dose–response study, the maximum adduct formation was 492.0 ng/g for 2-AMX, 505.5 ng/g for 2-AMK and 12588.5 ng/g for 4-AMX in liver at 0.03 mg/g MX and MK fish in 1 day after exposure. For toxicokinetics investigation, the highest amount of the target metabolites was found to be the same concentration as observed in the dose–response study for 1 day after exposure with 0.03 mg/g MX and MK fish and the half-lives of the metabolites were estimated to be 2–9 days based on assumption of first-order kinetics. Average recoveries exceeded 95% with a relative standard deviation (RSD) around 9%, and the limit of detection (LOD) ranged from 0.91 to 3.8 ng/g based on a signal to noise ratio of 10 ( S / N = 10) could be achieved for the metabolites. No metabolites were detected in the controls and exposed non-hydrolyzed liver extracts. This is the first report on dose–response and toxicokinetics of nitro musk-cysteine-protein adducts in fish liver.
Using documented written and oral dialogue to understand and challenge preservice teachers' reflections

Abstract The following case study describes two students' reported thinking related to emergent issues during their first field placement connected to a university course exploring topics related to reading instruction in elementary grades. Over the course of the semester, students submitted several documents that asked them to address issues related to reading instruction that they found relevant to their experiences in the field. Analysis of the data revealed that the students demonstrated very different ways of struggling with equity issues. The discussion focuses on what the documented dialogues revealed about the students' definitions of teaching and their apparent reflections. The conclusion argues for additional research investigating student teachers' reflections over time.
Body image satisfaction among intercollegiate female athletes using a scale of muscularity.

In recent years it has become more apparent that disordered eating and unrealistic concepts of attractiveness have created a major problem in women, especially young adult female athletes. The present study administed a variety of body image, dieting, and eating-oriented questionnaires to 61 female intercollegiate athletes. Track/Field, Soccer, Basketball, Cheerleading, Softball, and Volleyball were represented. Questionnaires included a pictorial body image scale that varied in terms of muscularity, the Eating Disorder Inventory (EDI), the Eating Attitudes Test (EAT), the Eating Habits Questionnaire (EHQ), and a food neophobic/neophilic scale (FNS). Female athletes in all sports chose an “IDEAL” figure which was less muscular than their “CURRENT” figure. Soccer players had the lowest body dissatisfaction and volleyball players had the highest. Among the EDI sub-scales, there was a significant difference between Track and Field and Basketball on the scale of Bulimina, with Track and Field being highest and Basketball being lowest. There was a trend in Perfectionism between Cheerleading being the lowest and Track and Field being the highest. In addition, there was a significant correlation between 6 of the 8 EDI sub-scales and body dissatisfaction. Drive for thinness, interceptive awareness, bulimia, body dissatisfaction, ineffectiveness, and maturity fears were all correlated with levels of body dissatisfaction. These results further support the need for intervention and education concerning promoting realistic body expectations among female athletes.
Numerical and Experimental Study of a Novel Phase Contrast Technique: Self Reference Phase-Contrast Magnetic Resonance Imaging

The quantitative measurement of blood flow using magnetic resonance imaging (MRI) has been a topic of research for over twenty years. At present, blood flow measurements are largely performed using two-dimensional phase contrast magnetic resonance (PC-MR). However, when high acceleration terms are present (i.e., valve regurgitation or stenosis), accuracy of conventional (Con) cardiac PC-MR can suffer: when data are acquired at a relatively poor temporal resolution, the data extraction process, which essentially is one of comparison, makes the Con PC-MR data sensitive to temporal acceleration. Here, a novel PC-MR technique termed Self Reference (SR) PC-MR is introduced that overcomes these limitations by eliminating the need for comparing paired data sets.Copyright © 2007 by ASME
Protecting Adolescents From Self-Harm: A Critical Review of Intervention Studies

Objective To review the studies that test treatments targeting adolescent suicidal ideation, suicide attempts, or self-harm, and to make recommendations for future intervention development. Method The extant randomized clinical trials that aim to reduce the intensity of suicidal ideation or the recurrence of suicide attempts or self-harm were reviewed with respect to treatment components, comparison treatments, sample composition, and outcomes. Results The majority of studies that showed any effect on suicidal ideation, attempts, or self-harm had some focus on family interactions or nonfamilial sources of support. Two of the most efficacious interventions also provided the greatest number of sessions. Some other treatment elements associated with positive effects include addressing motivation for treatment and having explicit plans for integrating the experimental treatment with treatment as usual. In many studies, suicidal events tend to occur very early in the course of treatment prior to when an effective "dose" of treatment could be delivered. Important factors that might mitigate suicidal risk, such as sobriety, healthy sleep, and promotion of positive affect, were not addressed in most studies. Conclusion Interventions that can front-load treatment shortly after the suicidal crisis, for example, while adolescent suicide attempters are hospitalized, may avert early suicidal events. Treatments that focus on the augmentation of protective factors, such as parent support and positive affect, as well as the promotion of sobriety and healthy sleep, may be beneficial with regard to the prevention of recurrent suicidal ideation, attempts, or self-harm in adolescents.
A meta-analysis of anxiety symptom prevention with cognitive-behavioral interventions

This meta-analysis assessed efficacy of cognitive-behavioral interventions in preventing anxiety symptoms. A systematic review identified 15 independent pretest-posttest randomized or quasi-randomized efficacy trials for analysis. At posttest, intervention groups demonstrated significantly greater symptom reduction compared to control groups resulting in weighted mean effect sizes (Hedges' g) of 0.25 for general anxiety, 0.24 for disorder-specific symptoms, and 0.22 for depression after the removal of outliers. These effects appeared to diminish over 6- and 12-month follow-up. Exploratory moderator analyses indicated that individually administered media interventions were more effective than human-administered group interventions at preventing general anxiety and depression symptoms. Implications of current findings are discussed with attention to existing gaps in the literature.
Heat flux field for one spherical inhomogeneity embedded in a functionally graded material matrix

Abstract The heat flux field for a single particle embedded in a graded material is derived by using the equivalent inclusion method. A linearly distributed prescribed heat flux field is introduced to represent the material mismatch between the particle and the surrounding graded materials. By using Green’s function technique, an explicit solution is obtained for the heat flux field in both the particle and the graded material. Comparison of the present solution with finite element results illustrates the accuracy and limitation of this solution.
The metabolism of corticosterone in the salt gland of the duck, Anas platyrhynchos.

Abstract The metabolic fate of [1,2,6,7- 3 H]-corticosterone in the salt glands of the mallard duck ( Anas platyrhynchos ) was studied. After 60 min of in vitro incubation, using a salt gland cytosol fraction, 25–40% (±5–12%) of the extracted labeled material migrated with 11-dehydrocorticosterone on thin layer chromatographs. The remaining 55–70% (±15–20%) of the labeled material migrated with corticosterone. However, 50–90% (±4–10%) of the protein-associated labeled material from the same cytosols migrated with 11-dehydrocorticosterone, while only 3–25% (±0.5–5%) migrated with corticosterone. Likewise, data from in vivo studies indicated that at 1, 5, and 11 min the total labeled compound in the cytosol which migrated with 11-dehydrocorticosterone was 48% (±8%), 85% (±12%), and 61% (±8%), respectively, while only 13% (±2%), 4% (±0.5%) and 10% (±2%), respectively, migrated with corticosterone. In addition, at 90 min 66% (±12%) still migrated with 11-dehydrocorticosterone and only 10% (±0.5%) migrated with corticosterone. The tentative conclusions from these data, therefore, are that salt glands accumulate corticosterone from the blood and metabolize it to 11-dehydrocorticosterone, which is the principal bound form of the steroid.
Brachial birth palsy

Abstract We stated at the beginning that we hoped to set out the problem of brachial birth palsy even though we have reached no completely satisfactory solution. As we see it, then, it comes down to this: At the time the orthopedist usually sees the patient the primary pathology is beyond redemption, and he has therefore to concern himself with either prevention (if possible) or correction of secondary pathology. To my mind the most important element in this is the subluxation of the shoulder joint rather than the contracture, though the two go hand in hand. The contracture can easily be dealt with, but if there is also subluxation of the humeral head there is still a very unstable base for the available muscle power to act upon. In the earlier cases the prevention of these secondary pathologic changes is in order. This is usually done by a brace holding the shoulder abducted to a right angle ( not beyond ) and externally rotated. It must be borne in mind, however, that a splint has no volition of its own and it is up to the surgeon to see that it is doing what he wants it to. We would add that the splint must be so designed and fitted that it not only holds the arm in abduction and external rotation but also holds the humeral head forward and in close contact with the glenoid. Otherwise it will not prevent deformity. If prevention measures do not achieve the desired result, then operative measures are in order. As to the choice of operation, it will vary with the individual cases. In general we feel that the Sever operation releasing the contracture gives better results when there is no subluxation of the joint. If there is subluxation we feel that one of the osteotomies or the Kleinberg operation which realizes the position of the humerus without disturbing the contracture are preferable. Transplantation of muscle about the shoulder is a tempting field but there are many difficulties involved. Deformity must be corrected first and a stable joint provided before it can be effective. So far as our own operation is concerned, we have had disappointments—perhaps because we hoped for too much—but few failures. We still feel that all the cases except two have been improved, though not to the extent we had hoped. We still believe that with more experience the technique can be improved to the point where it will be more effective. It is pondering over disappointments that gives one experience.
Use of neural nets in channel routing

The channel routing problem is solved using a massively parallel processor based on the artificial neural system (ANS) computational model. In this model the functional behavior of the human designer is emulated by expressing problem constraints as interconnection weights between neural cells (computational elements), using very simple computational elements for neural cells and massive parallelism to solve problems. The algorithm constraints are expressed as interconnection weights. By making the artificial neural cells work collectively on a task, a solution is obtained after each of the neural cells settles to a stable state. >
A Combination of Dopamine Genes Predicts Success by Professional Wall Street Traders

What determines success on Wall Street? This study examined if genes affecting dopamine levels of professional traders were associated with their career tenure. Sixty professional Wall Street traders were genotyped and compared to a control group who did not trade stocks. We found that distinct alleles of the dopamine receptor 4 promoter (DRD4P) and catecholamine-O-methyltransferase (COMT) that affect synaptic dopamine were predominant in traders. These alleles are associated with moderate, rather than very high or very low, levels of synaptic dopamine. The activity of these alleles correlated positively with years spent trading stocks on Wall Street. Differences in personality and trading behavior were also correlated with allelic variants. This evidence suggests there may be a genetic basis for the traits that make one a successful trader.
Ethanol inhibition of transport of 5-hydroxyindoleacetic acid from cerebrospinal fluid

MUCH work has been directed at demonstrating the possible interaction of ethanol with levels of neurotransmitter amines or their metabolism in brain1,2. We have previously demonstrated an increase in brain levels of 5-hydroxyindoleacetic acid (5-HIAA) in mice after both a single and chronic administration of ethanol3. Our more recent work4 has focused attention on the inhibition of transport of 5-HIAA from the central nervous system (CNS) by ethanol as the factor responsible for the increase in brain 5-HIAA after ethanol. 5-HIAA diffuses from the CNS into cerebrospinal fluid (CSF), from which it is removed by a carrier-mediated transport into the bloodstream5. The effect of ethanol on transport of 5-HIAA from CSF was studied by perfusing this acid through the spinal subarachnoid space from the cisterna magna to the lumbar region of cats. This was shown to be a sensitive and reliable model for the study of transport of 5-HIAA from CSF (ref. 6).
Low-complexity soft demapper for OFDM fading channels with ICI

We present a low-complexity soft demapper that computes bit log-likelihood ratios (LLRs) while suppressing orthogonal frequency division multiplexing (OFDM) inter-carrier interference (ICI). The proposed demapper consists of two stages and can be realized in a fully-parallel architecture. We examine uncoded and low-density parity-check (LDPC) coded performance over frequency-selective Doppler fading channels. We compare the coded and uncoded performances of our demapper with those of an MMSE detector with successive detection (MMSE-SD) and also the match-filter (MF) bound. We show that the proposed demapper achieves optimal performance in the system operating-SNR region. Given the proposed near-optimal demapper, complex receiver designs that iterate between the detector and the decoder may not be worthwhile
Focus on Lower Risk of Tardive Dyskinesia with Atypical Antipsychotics

Background. Tardive dyskinesia (TD) is one of the most serious iatrogenic neurological complications of the first-generation antipsychotics. Identifying the risk factors for TD is important to minimize the risk of this potentially irreversible movement disorder in susceptible populations.Methods. A Medline search was conducted for the literature on risk factors for TD with the first-generation antipsychotics, as well as the emerging literature of the lower risk of TD with the second-generation antipsychotics.Results. Several demographic, phenomenological, comorbidities and treatment variables have been reported to be associated with higher risk of TD. On the other hand, significantly lower rates of TD have been reported with the second-generation atypical antipsychotics, even in high risk groups such as the elderly.Conclusions. The use of the second-generation antipsychotics as first-line treatment of psychosis appears to have lowered the overall prevalence of acute movement disorders as well as TD, and h...
Synthesis, structure, and bridge-terminal alkyl exchange kinetics of pyrazolate-bridged dialuminum complexes containing bridging n-alkyl groups

Treatment of triethylaluminum with 3,5-diphenylpyrazole in a 2:1 stoichiometry afforded the ethyl-bridged complex Et2Al(l-Ph2pz)(l-Et)AlEt2 (79%) as a colorless crystalline solid. Treatment of tri-n-propylaluminum with 3,5-di-tert-butylpyrazole in a 2:1 stoichiometry afforded the n-propyl-bridged complex (nPr)2Al(l-tBu2pz)(l-nPr)Al(nPr)2 (63%) and the dimeric complex [(nPr)2Al(l-tBu2pz)]2 (3%), respectively, as colorless crystalline solids. Treatment of tri-n-propylaluminum (1 equiv.) or triisobutylaluminum (1 or 2 equiv.) with 3,5-di-tert-butylpyrazole afforded exclusively the dimeric complexes [(nPr)2Al(l-tBu2pz)]2 (68%) or [(iBu)2Al(l-tBu2pz)]2 (96%), respectively, as colorless crystalline solids. The solid state structures of Et2Al(l-Ph2pz)(l-Et)AlEt2 and (nPr)2Al(l-tBu2pz)(l-nPr)Al(nPr)2 consist of 3,5-disubstituted pyrazolato ligands with a di-n-alkylalumino group bonded to each nitrogen atom. An ethyl or n-propyl group acts as a bridge between the two aluminum atoms. The kinetics of the bridge-terminal exchange was determined for the bridging n-alkyl complexes by 13 C NMR spectroscopy, and afforded DH = 1.5 ± 0.1 kcal/mol, DS = � 46.8 ± 39.0 cal/K mol, and DG z298 KÞ ¼ 15:4 � 11:7 kcal=mol for Et2Al(l-Ph2pz)(l-Et)AlEt2 and DH = 1.7 ± 0.1 kcal/mol, DS = � 46.6 ± 43.4 cal/K mol, and DG z298 KÞ ¼ 15:6 � 11:7 kcal=molpz)(l-nPr)Al(nPr)2. The negative values of DS imply ordered transition states relative to the ground
Cadmium Chloride and Cadmium Metallothionein-Induced Pulmonary Injury and Recruitment of Polymorphonuclear Leukocytes

Pulmonary exposure of rats to either cadmium chloride (CdCl2) or cadmium metallothionein (CdMT) was previously reported to induce an influx of polymorphonuclear leukocytes (PMNs) to the airways, but only CdCl2 caused a significant increase in lung permeability, indicative of damage to the pulmonary epithelium. The purpose of this study was to investigate mechanisms of PMN recruitment following exposure to these forms of cadmium. Fischer 344 rats were intratracheally instilled with 10 micrograms cadmium in the form of CdCl2 or CdMT, and the time course of pulmonary inflammation and PMN migration activity was determined. PMN numbers, permeability, and PMN migration activity of lung lavage supernatant peaked 1 to 2 days after CdCl2 exposure. PMN migration activity was not detected 5 h after CdMT exposure, despite a peak of PMN numbers 10 h after exposure, but was increased by 1 day when permeability had increased to a small but significant degree. Elastase-modified forms of alpha-1-proteinase inhibitor (alpha 1PI), with molecular weights of 80 and 51 kd, have been reported to be highly chemotactic for PMNs. Antiserum to alpha 1PI significantly inhibited PMN migration activity detected in supernatants 1 day after exposure to either CdCl2 or CdMT. The results suggest that both CdCl2 and CdMT induce the formation of high molecular weight modified forms of alpha 1PI in the airways; these factors may traverse damaged epithelium to recruit PMNs from the vasculature. Additional small or lipophilic factors, undetectable by the methods of this study, may be responsible for the early influx of PMNs following CdMT exposure in the absence of increased epithelial permeability.
Natural gradient for minor component extraction

The paper proposes constrained optimization criteria for extracting in parallel multiple minor components using a weighted inverse Rayleigh quotient (WIRQ). This WIRQ is formulated into many constrained optimization problems which results in deriving many variations of MCA flows using the natural gradient concept. The derived minor component flows are analyzed and some of their convergence properties are presented. Procedures for converting MCA flows into a principal component flow are also discussed.
Role of Spatial Ability as a Probable Ability Determinant in Skill Acquisition for Sonographic Scanning

OBJECTIVES Spatial ability refers to an individual's capacity to visualize and mentally manipulate 3-dimensional objects. Because sonographers manually manipulate 2- and 3-dimensional sonographic images to generate renderings of anatomic structures, it can be assumed that spatial ability is an ability determinant for understanding and producing these medical images. Using the theory of ability determinants of skilled performance as a conceptual framework, this study explored the relationship of spatial ability and learning sonographic scanning. METHODS Beginning sonography students from 3 different types of educational institutions were administered a spatial ability test before their initial scanning laboratory course work. The students' spatial test scores were compared with their scanning competency performance scores after the first scanning competency test and then to the overall average of the competency scores for the 2 semesters. The spatial ability test was again administered after the 2-semester learning period to see whether the students' spatial ability had increased. RESULTS A significant relationship between the students' spatial ability test scores and their scanning performance scores was found after the first scanning competency (r = 0.46; P < .05), and also when averaging all competency scores throughout the learning period (r = 0.49; P < .05). A moderate increase in the spatial ability of the students was also found (r = 0.32; P < .05). The incoming grade point average was found to be more predictive of the students' scanning scores than spatial or ACT scores. No relationship was found between spatial ability and student retention. CONCLUSIONS High spatial test scores as well as a high incoming grade point average appear to be the best ability determinants in skill acquisition for sonographic scanning.
Brain potentials during affective picture processing in children

In adults, emotional (e.g., both unpleasant and pleasant) compared to neutral pictures elicit an increase in the early posterior negativity (EPN) and the late positive potential (LPP); modulation of these ERP components are thought to reflect the facilitated processing of, and increased attention to, motivationally salient stimuli. To determine whether the EPN and LPP are sensitive to emotional content in children, high-density EEG was recorded from 18 children who were 5–8 years of age (mean age = 77 months, SD = 11 months) while they viewed developmentally appropriate pictures selected from the International Affective Picture System. Self-reported ratings of valence and arousal were also obtained. An EPN was not evident following emotional compared to neutral pictures; however, a positivity maximal at occipital–parietal recording sites was increased from 500 to 1000 ms following pleasant pictures and from 500 to 1500 ms following unpleasant pictures. Comparisons between the EPN and LPP observed in children and adults, and implications for developmental studies of emotion, are discussed.
Designing Efficient Asynchronous Memory Operations Using Hardware Copy Engine: A Case Study with I/OAT

Memory copies for bulk data transport incur large overheads due to CPU stalling, small register-size data movement, etc. Intel's I/O Acceleration Technology offers an asynchronous memory copy engine in kernel space which alleviates such overheads. In this paper, we propose a set of designs for asynchronous memory operations in user space for both single process (as an offloaded memcpy()) and lPC using the copy engine. We analyze our design based on overlap efficiency, performance and cache utilization. Our microbenchmark results show that using the copy engine for performing memory copies can achieve close to 87% overlap with computation. Further, the copy engine improves the copy latency of bulk memory data transfers by 50% and avoids cache pollution effects. With the emergence of multi-core architectures, the support for asynchronous memory operations holds a lot of promise in reducing the gap between the memory and processor performance.
A Two-Population Evolutionary Algorithm for Constrained Optimization Problems

A new approach to solving constrained nonlinear programming problems using evolutionary computations is discussed. According to the method two populations are evolved, one population (females) is evolved inside the feasible domain of the design space and a second population (males) is evolved outside this feasible domain. Both populations can be independently subject to crossover and mutation operations and the design space explored. Female-male crossover however ensures the desirable increase in the search pressure upon the boundaries of the feasible space - it is known that in many optimization problems the global optimum is bounded. The experiments performed on three test objective functions of two variables show some promise of the proposed approach in that it can cope with both linear and nonlinear constraints and with nonconvex feasible domains.
pH-sensitive membrane peptides (pHLIPs) as a novel class of delivery agents

Abstract Here we review a novel class of delivery vehicles based on pH-sensitive, moderately polar membrane peptides, which we call pH (Low) Insertion Peptides (pHLIPs), that target cells located in the acidic environment found in many diseased tissues, including tumours. Acidity targeting by pHLIPs is achieved as a result of helix formation and transmembrane insertion. In contrast to the earlier technologies based on cell-penetrating peptides, pHLIPs act as monomeric membrane-inserting peptides that translocate one terminus across a membrane into the cytoplasm, while the other terminus remains in the extracellular space, locating the peptide in the membrane lipid bilayer. Therefore pHLIP has a dual delivery capability: it can tether cargo molecules or nanoparticles to the surfaces of cells in diseased tissues and/or it can move a cell-impermeable cargo molecule across the membrane into the cytoplasm. The source of energy for moving polar molecules attached to pHLIP through the hydrophobic layer of a membrane bilayer is the membrane-associated folding of the polypeptide. A drop in pH leads to the protonation of negatively charged residues (Asp or Glu), which enhances peptide hydrophobicity, increasing the affinity of the peptide for the lipid bilayer and triggering peptide folding and subsequent membrane insertion. The process is accompanied by the release of energy that can be utilized to move cell-impermeable cargo across a membrane. That the mechanism is now understood, and that targeting of tumours in mice has been shown, suggest a number of future applications of the pHLIP technology in the diagnosis and treatment of disease.
Suspension feeding: Basic mechanisms controlling recognition and ingestion of larvae

Oysters (Crassostrea virginica) are valuable subjects for investigations of basic mechanisms regulating suspension feeding on invertebrate larvae. In separate laboratory experiments, we introduced inert particles or larvae to the oyster mantle cavity. Small inert particles ( 100~pm diam) equal to larvae in size were rejected. Neither particle specific gravity nor phytoplankton in the seawater medium affected ingestion of inert particles or larvae. Oysters consumed a wide range of invertebrate larval forms, including conspecific veligers. Nearly all larvae (> 75%) delivered to the oyster mantle cavity, except those of Bug&a neritina, were eaten and digested. Feeding stimulants in the larvae were a mixture of polar and nonpolar compounds that were insoluble in seawater. Although contrasting mechanisms regulated fteding on different-sized particles, ingestion of larvae was strictly controlled by particle surface chemistry (=flavor).
Rapid identification of important periodontal microorganisms by cultivation

Two recent developments have made possible rapid isolation and identification of important periodontal species. Selective media have been designed which demonstrate high recovery efficacy of black-pigmented Bacteroides spp., Actinobacillus actinomycetemcomitans, Eikenella corrodens, Fusobacterium spp., Capnocytophaga spp. and other periodontal bacteria. Presumptive tests for identification of periodontal isolates that are rapid and easy have also been described. Available microbiological methods permit even small microbiology laboratories to screen periodontal samples for suspected pathogens.
Transcapillary exchange in relation to capillary circulation.

Transcapillary exchange of diffusible solutes depends on capillary blood flow, Q; capillary permeability, P; and capillary surface area, S. In a single capillary, the extent of equilibration of a given solute depends on the ratio of Q, to the product of P and S. In a microvascular bed consisting of many capillaries, equilibration depends on the fraction of them which are open to blood flow at any time and on the distribution of Q/PS ratios in the open capillaries. Both these characteristics are subject to control by vascular smooth muscle, particularly by the precapillary sphincters. Vasomotor mechanisms have been shown experimentally to exert a wide range of effective control over blood-tissue transport. In skeletal muscle, effective PS measured with 42K or 86Rb may be increased 8-fold from maximum nervous vasoconstriction to optimum metabolic vasodilatation. Most probably, these changes are due to differences in functional capillary surface area and of blood flow distribution relative to permeability and surface area. The extent to which variations in permeability itself can contribute to control of transcapillary exchange is not known.
A new method of treating vector analysis

A novel method of treating vector analysis is suggested. By means of this method the three basic functions in vector analysis, namely, the gradient, the divergence and the curl and the integral theorems involving these functions can be derived by a relatively simple and orderly approach. All vector identities can be obtained by an algebraic manipulation without performing the differentiation. The key feature of this work is to introduce an operational expression with a symbolic operator which is more general than the conventional del operator. The rest of the analysis is straightforward. >
Sensorimotor gating, orienting and social perception in schizophrenia

Basic neurocognition and social cognition appear to influence the social impairments of persons with schizophrenia. This study examined relationships between two very basic automatic processes (i.e., sensorimotor gating and orienting) and social perception in schizophrenic patients. Thirty outpatients with schizophrenia completed psychophysiological measures of sensorimotor gating (prepulse inhibition, PPI), orienting (prepulse facilitation, PPF), and social perception (the Half Profile of Nonverbal Sensitivity, Half PONS). A median split was used to divide patients into poor and good gaters and poor and good orienters. Analyses revealed that patients with good PPI scored significantly higher on the Half PONS than patients with poor PPI. PPI showed a significant correlation (r=-0.54) with Half PONS performance, indicating that schizophrenia patients who were better able to gate out competing stimuli (i.e., less startle) were also better at detecting relevant social cues. Orienting (PPF) and social perception were not related. This study is the first to our knowledge to demonstrate an association between sensorimotor gating and social perception. The findings are consistent with other studies that have demonstrated relationships between basic neurocognition and social cognition. By showing a link between sensorimotor gating and social perception, this study supports social cognition's potential role as a mediator of the relationship between neurocognition and social functioning in schizophrenia.
Mapping vegetation types using SIR-C data

Supervised classification using multi-frequency, polarimetric-radar data from the NASA/JPL AIRSAR system has been most successful, with a demonstrated capability to separate many different classes of vegetation. Models of radar interaction with vegetation suggest strongly that this capability is due to radar's sensitivity to the vegetation structure in the canopy and in the trunks or stems and understory. Recently, an approach has been adopted in the radar remote sensing community to first perform an unsupervised classification on the data into simple classes, such as forest, grassland, bare soil, water, urban areas, etc. This initial classification can then be used as a starting point for a supervised classification into further subclasses. The success of classification using AIRSAR suggests that similar results can be achieved with the Spaceborne Imaging Radar SIR-C. Results obtained from the two SIR-C missions so far indicate that this is the case. A major difference between the airborne and spaceborne radar data are that the spaceborne data covers a much smaller range of incidence angles. This means that the backscatter does not vary dramatically across the swath as in the airborne case. Thus in using SIR-C data one can train on one area in an image and expect the results to be applicable all the way across the image. In this paper, results on vegetation classification using SIR-C data are presented for two sites: an agricultural site (Flevoland) in the Netherlands and a tropical rain forest area near Manaus in Brazil. Results will be compared with AIRSAR results for the Flevoland site.
Nitrogen fixation in Clear Lake, California. 4. Diel studies on Aphanizomenon and Anabaena blooms1

Day and night measurements of Nz fixation (as acetylene reduction) were made during spring blooms of Aphanixomenonjlos-aquae and two autumn blooms of Anabaena spp. From 9 to 23% of the 24-h fixation occurred between 1100 and 1300 hours. Nitrogen fixation in spring showed complex, physically shallow but optically deep and mobile subsurface peaks of nitrogenase activity, which were totally unrelated to Aphanixomenon biomass but may have been due to diel changes in light penetrating the relatively clear water. Nocturnal fixation was uniformly distributed with depth and accounted for t/J to $5 of daylight fixation. In more turbid autumn waters, the pattern of N2 fixation for Anabaena blooms was simpler, with a surface (or near-surface) peak decreasing with depth. Nocturnal fixation was more uniformly distributed with depth. The difference in fixation patterns between the two species is attributable to the interactions of oxygen with the nitrogenase enzyme system. The diel changes in nitrogenase activity suggest a need to establish whether the precursors of nitrogenase accumulate in an oxygen-stable form.
Rate-distortion optimized streaming for 3-D wavelet video

We propose a rate-distortion optimized framework to stream scalable bitstreams of 3-D wavelet video stored at the sender to a remote receiver. Based on the source rate-distortion profiles, the desired playout deadline, transmission rate, and the network characteristics, the receiver issues customized requests throughout the video playout session in order to retrieve the data that minimize the distortion in the reconstructed frames. Rate-distortion optimized data request is formulated as a convex optimization problem. Experimental results show that the proposed scheme improves the video quality by up to 3.1 dB over the heuristic scheme at the same rate, or correspondingly reduces the required the transmission rate by up to 60% for the same quality.
A model for duration coding in the inferior colliculus

We have implemented a biophysically-plausible model of duration-sensitive cells in the inferior colliculus which process the output of an auditory nerve model using temporal interactions between excitation and inhibition. Duration tuning results from temporal coincidences between an offset response and a delayed onset response. Model cells tuned to a range of best durations were tested with signals having durations between 2 ms and 40 ms. The model accurately simulated the duration tuning seen in the physiological data of Casseday et al. (1994) and also successfully simulated the effects of inhibitory blockers.
Effects of Contract Provisions on the Success of a Futures Contract

This article investigates the effect of contract provisions in attracting hedgers to a futures market. The new pork bellies futures contract initiated in 1961 resulted in very light trading during the first 18 months. Six provisions of the contract which caused dissatisfaction among traders were those dealing with shrinkage allowance, limitations on storage time, grades and standards, transportation allowance, methods of storage protection, and delivery time. After these provisions were revised in 1962 and 1963 in such a way as to bring them into closer correspondence with trade practices, hedger utilization increased rapidly and steadily.
Imperio del Derecho versus imperio de los Jueces: Un alegato por el pluralismo jurídico

This paper states that the absolute concentration of legal interpretation power in a supreme court is an error; moreover in times when judges themselves around the world are less convinced that the law is more a science than it is politics. It is argued that the alternative to monism is not necessarily disorder. Instead, it could be Legal Pluralism. The official interpretation of the law can be divided or balanced rather than completely merged or eliminated. It is likely that with a correct balance between the powers' separation and the stoppage and counterbalance system there won't be a principie solution to the tension underlying in the ideal of the Rule of Law, yet practical alternatives are offered to the choice among tyranny and disorder.
Medical management of ulcerative colitis

Initial treatment of mild to moderately active UC may be sulfasalazine, oral or rectal mesalamine, balsalazide, corticosteroid enemas, or oral corticosteroids. Patients with persistent mild to moderate symptoms of active UC in spite of these therapies (treatment-refractory) may require AZA/6-MP, and in some cases intravenous corticosteroid or transder-mal nicotine. Patients with severely active UC should be treated with intravenous conventional corticosteroids, and intravenous cyclosporine may be considered in those who do not respond. Remission should be maintained with sulfasalazine, oral or rectal mesalamine, olsalazine, or balsalazide, and in some cases with AZA/6-MP.
Colorectal cancer: Overcoming resistance to anti-EGFR therapy — where do we stand?

In the past few years, the mechanisms leading to an acquired resistance to anti-EGFR monoclonal antibodies became an important topic in metastatic colorectal cancer research. In this commentary, we briefly summarize the latest update to this field by Arena and colleagues, and discuss promising new drugs and treatment strategies that might lead to overcoming secondary resistance.