cssi/SciSciGPT-SciSciNet huggingface dataset:
Quantitative drop analysis. VI. Total nitrogen by diffusion

A diffusion method for analysis of nitrogen containing solutions on the drop scale is described. The amounts of nitrogen in the samples reported varied between 1.18γ and 9.46γ. A new type of diffusion cell making this determination possible is described. The mean error over the range reported was about 1 percent with the maximum error of the lowest amounts, about 5 percent.
Heat capacities of various solid linear macromolecules

Abstract Heat capacities at constant pressure and constant volume for the solid state are calculated from approximate vibrational spectra and compared with experimental data taken from a critical literature review. A total of 12 macromolecules are discussed: poly(isobutyl acrylate), poly(isobutyl methacrylate), poly(vinyl alcohol), poly(vinyl acetate), polyoxypropylene, poly[oxy-2,2-bis(chloromethyl)trimethylene], poly(vinyl benzoate), poly(vinyl p -ethylbenzoate), poly(vinyl p -isopropylbenzoate), poly(vinyl p -isopropylbenzoate), poly(vinyl p -t-butylbenzoate), polycyclopentene and cis -1,4-polyisoprene. The results are compared with prior approximations on about 70 other polymers. For poly(vinyl acetate) new ‘recommended data’ are presented. The influence of methyl groups on heat capacity is discussed.
An Application of Exposure Modeling in Exposure Assessments for a University Chemistry Teaching Laboratory

Abstract Chemical exposures in a university teaching lab were assessed using a tiered approach to modeling. Zero ventilation and well mixed room models estimated air concentrations of ethyl ether, n-hexane, and methylene chloride during distillation and extraction exercises. A simple, zero ventilation model determined that health risks from the ethyl ether exercise were minimum. N-hexane and methylene chloride exposures were evaluated with higher tiered, well mixed room models. An assumption that all of the solvent evaporated during the lab resulted in estimated n-hexane concentrations well below the occupational exposure limit. Methylene chloride concentration estimates using this approach were only one-half the occupational exposure limit, so the model was refined using information on the actual amount of solvent that evaporated. This resulted in a concentration estimate approximately one-fifth of the occupational exposure limit. Air sampling was done to evaluate model performance. Measured concentratio...
Henry Kunkel Festschrift

This Festschift by his former trainees is dedicated to the memory of Dr Henry G Kunkel. Dr Kunkel spent most of his academic life at The Rockefeller University. He has been called the father of Cli...
Math Portfolios in the Primary Grades

(1997). Math Portfolios in the Primary Grades. Childhood Education: Vol. 73, No. 4, pp. 194-199.
Decoupling policy from configuration in campus and enterprise networks

This paper surveys our ongoing work on the use of software-defined networking to simplify two acute policy problems in campus and enterprise network operations: access control and information flow control. We describe how the current coupling of high-level policy with low-level configuration makes these problems challenging today. We describe the specific policy problems faced by campus and enterprise network operators; illustrate our approach, which leverages recent trends in separating the network's “control plane” from the data plane; and show how this approach can be applied to simplify these two enterprise network management tasks. We also describe our ongoing deployment efforts to build a campus network testbed where trial designs can be deployed and evaluated. We close with a summary of current and future research challenges for solving challenges within enterprise networks within the context of this new paradigm.
The Role of Cadherin, β-Catenin, and AP-1 in Retinoid-regulated Carcinoma Cell Differentiation and Proliferation

Vitamin A derivatives (retinoids) are potent regulators of cell proliferation and differentiation. Retinoids inhibit the function of the oncogenic AP-1 and beta-catenin/TCF pathways and also stabilize components of the adherens junction, a tumor suppressor complex. When treated with retinoic acid (RA), the breast cancer cell line, SKBR3, undergoes differentiation and reduction in cell proliferation. The present work demonstrates that in SKBR3 cells, which exhibit high AP-1 activity, RA-regulation of cadherin expression and function, but not changes in AP-1 (or beta-catenin/TCF) signaling, is responsible for the epithelial differentiation. However, cadherin function and recruitment of beta-catenin to the membrane is not required for RA to regulate DNA synthesis in these cells. RA also reduces the activity of an AP-1 and TCF-sensitive cyclin D1 reporter in SKBR3 cells in a manner that is independent of the TCF site. In contrast, in SW480 cells, which have high levels of beta-catenin/TCF signaling, the activity and retinoid responsiveness of the cyclin D1 promoter was markedly inhibited by mutation of the TCF site. These data indicate that the remarkably broad effects of RA on the growth and differentiation of many different epithelial cancers may well be explained by the ability of RA to differentially regulate the activity of RAR/RXR, AP-1, and beta-catenin/TCF pathways.
Feeding, exploratory, anxiety- and depression-related behaviors are not altered in interleukin-6-deficient male mice.

Interleukin-6 (IL-6) has been implicated in behavioral responses associated with inflammation, sickness behavior and various nervous system disorders. We studied a range of different behaviors in IL-6-knockout (IL-6ko) and wild-type (WT) male mice. No significant differences were observed in ambulatory, exploratory, and stereotypic activities in home or novel cages, in an open field (OF), in the multicompartment chamber (MCC), or in the elevated plus-maze (EPM). IL-6ko mice shed fewer fecal boli than WT mice in the OF, in novel cages and in the MCC although this effect was not statistically significant in the OF. In novel cages, intraperitoneal (i.p.) injection of IL-6 (1 μg) depressed ambulatory activity slightly more in IL-6ko than in WT mice. Restraint and interleukin-1β (IL-1β, 100 ng i.p.) decreased exploration of mice in the MCC and EPM, but there was no indication of altered sensitivity in IL-6ko mice. No significant differences were detected in the tail suspension and the Porsolt forced swim tests. IL-1β and lipopolysaccharide (LPS 1 μg i.p.) injection depressed sweetened milk and solid food intake similarly in IL-6ko and WT mice, but IL-6 had no effect, suggesting that IL-6 is not involved in these effects of IL-1 or LPS. However, IL-1β and LPS depressed body weight more in WT than in IL-6ko mice. Plasma corticosterone and basal concentrations of catecholamines, indoleamines and their metabolites in several brain regions were similar. The responses in these measures to IL-1β and LPS were also similar, except that there were no significant changes in tryptophan and serotonin metabolism in IL-6ko mice. This may reflect a role for IL-6 in the tryptophan and serotonin responses to IL-1 and LPS. It is concluded that the lack of IL-6 is not associated with substantial alterations in several different mouse behaviors, and in the responses to restraint, IL-1β, IL-6 and LPS.
Analysis of ultrawideband pulses in a GTEM cell

A data compensation routine using deconvolution technique for an ultra-wide-band (UWB) exposure facility is described. The single shot measuremetn system mainly includes a Tektronix SCD 5000 sampling scope and an EG&G D-dot sensor. The transfer function of the measuremetn system was evaluated with a reference impulse generated by a picosecond pulse labs 4050B picosecond pulse generator. An iterative Hilbert transform was applied to ensure the causality of the results of deconvolution. With software compensation, the bandwidth of the measurement system has been expanded from less than 2 GHz to about 15 GHz. The analysis shows that this exposure system can deliver UWB pulses with a rise time less than 150 ps, a magnitude from 50 to 120 kV/m depending on the location along the center line, and a pulse width about 5 ns.
CHRONIC OBSTRUCTION OF PERIPHERAL AIRWAYS AND HYPOXEMIA IN ASTHMATIC CHILDREN

Both in vivo and in excised lungs, the nitrogen washout alveolar plateau (phase 3 slope) correlates with histopathologically detected obstruction of peripheral airways. We hypothesized that children with abnormally steep phase 3 slopes between episodes of asthma should exhibit both hypoxemia and relatively severe clinical courses because of chronic obstruction of peripheral airways. To test this, we measured phase 3 slope and supine arterial oxygen saturation (SaO2, by ear oximetry) and reviewed the clinical histories of 25 children in stable condition between episodes of wheezing. We found that the 7 children with abnormally steep phase 3 slopes also had the lowest values for SaO2 (mean 93.7±1.4 SD %). Phase 3 slope had a significant negative correlation with SaO2. There was no correlation between SaO2 and expiratory flow rate, density dependence of expiratory flow or the ratio of residual volume to total lung capacity. During the year preceding the study, outpatient visits resulting in injections of adrenaline were significantly more frequent in the 7 children with steep phase 3 slopes than in the 18 with normal phase 3 slopes (P< .05). We conclude 1) groups of asthmatic children with and without persistent obstruction of peripheral airways can be identified by the single breath nitrogen washout and 2) those children with persistent obstruction of peripheral airways tend to be hypoxemic and have a relatively high incidence of status asthmaticus.
Attributions of shy persons in romantic relationships

The present research examined attributions of shy persons in the interpersonal situation of romantic relationships. Two hundred fifteen undergraduate psychology students were administered the Beck Depression Inventory (BDI), the Social Avoidance and Distress Scale (SAD), and the Romantic Relations Attributions Questionnaire (RRAQ). Correlations are reported for both the SAD and the BDI with the RRAQ. Partial correlations of the SAD with the RRAQ with depression removed also are reported. Results suggest that shy people attribute causality in romantic relationships in ways typically associated with depressed people. Moreover, observed gender differences suggest that shy females may be more committed to making a relationship work, whereas shy males may be more willing to abandon a problematic relationship.
Primal graphs with small degrees

Abstract It has previously been shown that there is a unique set Π of primal graphs such that every graph has an edge-decomposition into non-isomorphic elements of Π and that the only decomposition of an element of Π into non-isomorphic elements of Π is the obvious one. Here it is shown that there are infinitely many elements of Π even among graphs having a relatively simple structure. On the other hand, within this same class of graphs, we show that ‘most’ of them are not primal.
INDUCED MATURATION AND SPAWNING OF MARINE FISH AT THE SOUTHWEST FISHERIES CENTER LA JOLLA, CALIFORNIA

Technical details are given for spawning the following fish under controlled laboratory conditions: the northern anchovy (Engraulis mordax), Pacific mackerel (Scomber japonicus), croaker (Bairdiella icistia), and striped bass (Morone saxatilis).
Sex Differences in Schizophrenia

Demographic and clinical characteristics of 275 schizophrenics consecutively admitted to seven hospitals were examined. Males were younger than females when first hospitalized, diagnosed and treated. Psychiatrists rated on two rating scales by using a structured interview to compare the symptomatology. Female schizophrenics were more agitated, inappropriate, silly, irrelevant, over-talkative, and exhibiting more flight of ideas, while male schizophrenics were more slowed, hypoactive, grandiose, withdrawn, and showing more blocking, auditory hallucinations and poor communications. Katz Adjustment Scales were rated by the patients and their relatives. Female schizophrenics were perceived by relatives to be more helpless and withdrawn-depressed than male schizophrenics.
Rapid 4-Stokes parameter determination using a motorized rotating retarder

A motorized rotating retarder, a linear polarizer, and a digital camcorder are used to obtain polarization profiles of natural daylight scenes. A correlation technique synchronizes real-time video frames with respect to the rotating retarder's fast axis. Polarization parameters are calculated for each red-green-blue (RGB) channel and scene pixel. Extending the quasimonochromatic approximation to larger bandwidths is solved by expressing the Stokes parameters explicitly as functions of wavelength. A detailed numerical analysis examines errors due to ill-conditioning effects that are associated with specific relative angular orientations of the optical components. A comparison of the theoretical results with empirical data from the digital camcorder provides a validation process for the results in this paper. A RGB pseudocolor encoding algorithm provides a means to visualize the polarization imagery. An ellipticity study was conducted during the early morning hours when scene lighting conditions change rapidly. A comparison of the results from a digital still camera, using a 30-s data acquisition time period, was made with respect to a 0.6-s time period for the rotating retarder configuration. The results clearly show that errors due to temporal registration effects are dramatically reduced as the time interval between images goes to zero.
Positioning sex educators: a critical ethnography of a professional development workshop

In this ethnographic research, I offer an analysis of a state-sponsored professional development workshop for sex educators. Positioning theory is used to understand how the lived space of the workshop – including texts, talk and silence – positions sex education teachers as professionals and practitioners with certain (limited) speaking rights and resources.
Influence of participation in a cup-stacking unit on timing tasks

Cup stacking is a relatively new activity which has been promoted at conferences for physical educators as having many direct and indirect benefits, such as improved quickness. This study examined the influence of a cup-stacking instructional unit on reaction and anticipation times of 69 children in Grades 2 and 4. Within each grade participants were assigned to an experimental or a control group. The former received a 3-wk. instructional unit following the lesson plans provided by the promoters of cup stacking. The control groups received a standard physical education curriculum. Analysis indicated no significant differences in reaction and anticipation times between the groups before and after practicing the instructional unit.
An Immunoblot Study of Neurofilament Degradation In Situ and During Calcium‐Activated Proteolysis

: The degradation of neurofilament (NF) proteins was examined by immunoblot methods to identify, characterize, and monitor the appearance of immunoreactive breakdown products during the loss of NF triplet proteins. Individual NF proteins and their breakdown products were identified using polyclonal and monoclonal antibodies to NF proteins. NF degradation was compared during calcium-activated proteolysis of isolated rat NF, during an experimental influx of calcium into excised rat spinal nerve roots, and during NF breakdown in transected rat peripheral nerve. These different experimental conditions produced similar patterns of NF fragmentation, including the transient appearance of NF immunobands between Mr 150,000–200,000 and 110,000–120,000 as well as the appearance and accumulation of NF immunobands between Mr 45,000 and 65,000. Most immunoreactive NF fragments remained Triton-insoluble. Low levels of the same immunoreactive fragments were present in control neural tissues, suggesting that calciumactivated proteolysis may be operative in the turnover and/or processing of NF proteins in vivo. Very similar patterns of NF degradation during experimental calcium influxes into different CNS and PNS tissues are indicative of the widespread distribution of calcium-activated NF protease in neural tissues.
Marjolin's ulcer : immunohistochemical study of 17 cases and comparison with common squamous cell carcinoma and basal cell carcinoma

Formalin-fixed, paraffin-embedded biopsy specimens of 17 cases of squamous cell carcinoma of Marjolin's ulcer (SCC-MU), 6 cases of common SCC (SCC), and 5 cases of basal cell carcinoma (BCC) were stained with three monoclonal antikeratin antibodies (CAM 5.2, MAK-6, and MA-903), a monoclonal antivimentin antibody (V9), and a polyclonal anticarcinoem-bryonic antigen antiserum (A115). Neoplastic cells of SCC-MU, SCC, and BCC showed consistently negative staining for CAM 5.2. A wide range of reactivity, from negative to diffuse strong positivity, among neoplastic cells of SCC-MU and SCC was noted with MAK-6. Alternatively, neoplastic cells of SCC-MU, SCC, and BCC consistently showed diffuse moderate to strong reactivity with MA-903. These findings imply that SCC-MU has largely high-molecular-weight keratins. They also showed a wide-range of reactivity with V9. However, neoplastic cells of five of the six SCC and five cases of BCC were negative for V9. These findings suggest that neoplastic cells of SCC-MU contain vimentin in higher frequency than in the more usual SCC.
Dose-Response Relationship Between Thyroid Hormone and Growth Velocity in Cynomolgus Monkeys

To investigate the dose-response relationship between thyroid hormone and linear growth, we studied 10 castrated prepubertal cynomolgus monkeys. Hypothyroidism was induced by administration of methimazole (0.0125% in drinking water) and was confirmed by high serum TSH levels (greater than 40 mU/L) in all animals. Subsequently, each animal received 1, 2, 4, or 8 micrograms/kg.day T4, im, for 9 weeks. The sequence of T4 doses was random, and 6 weeks elapsed between successive T4 doses. Serum T4, T3, TSH, and insulin-like growth factor I (IGF-I) levels and lower leg length were measured every 3 weeks. Methimazole administration decreased thyroid hormone and IGF-I levels and lower leg growth rate. With increasing doses of exogenous T4, serum T4, T3, and IGF-I as well as lower leg growth rate increased significantly. Animals not given T4 had a 65% decrease in lower leg growth rate (P less than 0.01). Animals given 4 and 8 micrograms/kg.day T4 had 56% and 73% increases, respectively, in lower leg growth rate compared to baseline (P less than 0.05 and P less than 0.01, respectively). Lower leg growth rate correlated better with serum T3 (r = 0.50; P less than 0.001) than with serum T4 (r = 0.29; P less than 0.05). Lower leg growth rate also correlated with serum IGF-I levels (r = 0.53; P less than 0.001). Serum IGF-I correlated with serum T3 (r = 0.47; P less than 0.001), but not with serum T4. We conclude that increased serum T4 and T3 levels cause progressive increases in growth velocity and IGF-I levels over a range from moderate hypothyroidism to moderate hyperthyroidism. Growth velocity and IGF-I levels correlated more strongly with the serum T3 than with the serum T4 level.
Knowledge-based clustering scheme for collection management and retrieval of library books

Abstract We propose a knowledge-based clustering scheme for grouping books in a library. Such a grouping is achieved with the help of domain knowledge in the form of the ACM CR (Computing Reviews) category hierarchy. A new knowledge-based similarity measure is defined and used in clustering books. The proposed scheme is useful in overcoming several problems associated with the existing book collection management and document retrieval systems. More specifically, it can be used in: (1) helping the user select an appropriate collection of books in a library which contains the topics of interest; (2) assigning a classification number to a new book; (3) designing a more appropriate and uniform classification scheme for books; and (4) comparison of libraries based on their collections. Initial experiments on a collection of hundred books using the proposed clustering scheme have given us encouraging results.
SVM-based classifier design with controlled confidence

A new classification methodology with controlled error rates and a reject option is proposed in this paper. The proposed methodology is implemented using support vector machine's (SVM's) posterior probability preserving property. A new nonparametric method is proposed to accurately estimate error rates from the output of a trained SVM. The experimental results clearly demonstrate the efficacy of the suggested classifier design methodology.
Turn-of-the-century ethical issues in child psychiatric research.

National concern in 2000 about increased psychoactive drug prescription for preschoolers accentuated the 1990s thrust for more pharmacologic research in children. Preschoolers are prescribed potent drugs without adequate evidence for efficacy or safety at this plastic age of the rapidly developing brain. Implementation of needed preschool research poses special ethical complications. Children with mental disorder qualify for special protection under both rubrics. Parental informed consent is crucial for preschoolers, who appear incapable of assent because of their preoperational, magical, animistic, egocentric thinking, with inability to comprehend relative risks and benefits. Whether they can dissent is an open question. Possibly for research with direct benefit outweighing the risk, parental permission/consent could override attempted preschooler dissent. Subject recompense should be adjusted for age differences in perception of amount, although parent reimbursement needs to be realistic. Insurance for research risk is desirable. Placebo controls appear justified for preschoolers because there is little evidence base to say that a proven effective treatment already exists. Disruptive behavior disorders, including attention-deficit/ hyperactivity, have enough evidence of preschool diagnostic validity to justify therapeutic trials. In preschool pharmacologic research, a brief trial of a nonpharmacologic treatment should precede the drug trial to ensure that placebo responders and responders to the alternative treatment are not exposed to drug risk.
Late Cretaceous Precessional Cycles in Double Time: A Warm-Earth Milankovitch Response

Late Cretaceous climatic cycles are reflected in lithological and magnetic variations in carbonate sediments from South Atlantic Deep-Sea Drilling Project site 516F at a paleolatitude of roughly 30 degrees S. Magnetic susceptibility cycles 20 to 60 centimeters in length appear to be controlled by the precession of the equinoxes. Cyclicity is particularly robust within a 24-meter interval in the lower Campanian, where overtone spectral peaks are observed as well as secondary susceptibility maxima within individual precession cycles. One model for this behavior is that sedimentation in the narrow Cretaceous South Atlantic was controlled by equatorial climate dynamics, with the precessional insolation signal rectified by the large land masses surrounding the ocean basin.
Projective drawings and children who stutter

Abstract Five young stutterers (aged 5–10 yr) and a matched group of five nonstuttering children completed five projective drawings and a scale for assessing communication attitudes of children at the beginning and at the end of a 3-mo treatment period. While the attitude scale failed to indicate differences between stuttering and nonstuttering children, performances on selected drawings did distinguish between experimental and control subjects. In addition, significant changes were observed in selected drawings over the treatment period for the young stutterers.
Comments on an approximation coefficient proposed in 'stochastic model simplification

It is pointed out that the approximation coefficient defined in the above paper does not always satisfy the claimed properties. An alternative definition is suggested.
Adiabatic Markov Decision Process with application to queuing systems

Markov Decision Process (MDP) is a well-known framework for devising the optimal decision making strategies under uncertainty. Typically, the decision maker assumes a stationary environment which is characterized by a time-invariant transition probability matrix. However, in many realworld scenarios, this assumption is not justified, thus the optimal strategy might not provide the expected performance. In this paper, we study the performance of the classic Value Iteration (VI) algorithm for solving an MDP problem under non-stationary environments. Specifically, the non-stationary environment is modeled as a sequence of time-variant transition probability matrices governed by an adiabatic evolution inspired from quantum mechanics. We characterize the performance of the VI algorithm subject to the rate of change of the underlying environment. The performance is measured in terms of the convergence rate to the optimal average reward. We show two examples of queuing systems that make use of our analysis framework.
Optics for element-resolved soft X-ray magneto-optical studies

The status of polarizing optical elements for the vacuum ultraviolet and soft X-ray range extending from roughly 50 to 2000 eV are reviewed, as are some of their emerging applications in magneto-optical studies utilizing synchrotron radiation. The optics include tunable linear polarizers and birefringent phase retarders based on multilayer interference structures, and circular polarizing filters based on magnetic circular dichroism. Magneto-optical capabilities enabled by these optical elements include measurement of Faraday and Kerr rotation spectra and hysteresis loops, and the conversion of linear to circular polarization and helicity switching. Circular polarizers combined with scanning zone plate microscopes yield magnetization contrast in transmission imaging. Examples using these capabilities to study polycrystalline Fe films and Fe/Cr multilayers are given. Resonant soft X-ray magneto-optical spectroscopies are especially relevant to obtaining an understanding of magnetism on a microscopic level in complex materials and nanostructures because their element-specific signals can be larger than in other spectral ranges. Combined with scattering and microscopy techniques these spectroscopies can provide depth sensitive and lateral spatial resolution on the nanometer scale.
Experimental and theoretical studies of the phenyl radical reaction with propene.

The kinetics for the reaction of C 6 H 5 with propene has been measured by cavity ring-down spectrometry (CRDS) at temperatures 296-496 K under an Ar pressure of 40 Torr. The total rate constant can be given by the following Arrhenius expression (in units of cm 3 mol -1 s -1 ): k(C 6 H 5 + C 3 H 6 ) = 10 11.93±0.06 exp[-(1512 ± 51)/T]. Density functional and higher level of theory calculations (up to the G2M level) have been carried out to provide additional insights about the mechanism of this reaction, and we also performed transition state theory (TST) calculation for the rate constant prediction. Our theoretical kinetic calculations predict that the C 6 H 5 addition to the terminal =CH 2 site in propene is dominant at the temperature range of our CRDS measurements. However, the H-abstraction channel forming benzene and the allyl radical becomes increasingly important at higher temperatures. The total high-pressure limiting rate constant calculated on the basis of the G2M reaction barriers is in reasonable agreement with the experimental values.
Use of Population-based Surveillance to Define the High Incidence of Shigellosis in an Urban Slum in Nairobi, Kenya

Background: Worldwide, Shigella causes an estimated 160 million infections and .1 million deaths annually. However, limited incidence data are available from African urban slums. We investigated the epidemiology of shigellosis and drug susceptibility patterns within a densely populated urban settlement in Nairobi, Kenya through population-based surveillance. Methods: Surveillance participants were interviewed in their homes every 2 weeks by community interviewers. Participants also had free access to a designated study clinic in the surveillance area where stool specimens were collected from patients with diarrhea ($3 loose stools within 24 hours) or dysentery ($1 stool with visible blood during previous 24 hours). We adjusted crude incidence rates for participants meeting stool collection criteria at household visits who reported visiting another clinic. Results: Shigella species were isolated from 224 (23%) of 976 stool specimens. The overall adjusted incidence rate was 408/ 100,000 person years of observation (PYO) with highest rates among adults 34–49 years old (1,575/100,000 PYO). Isolates were: Shigella flexneri (64%), S. dysenteriae (11%), S. sonnei (9%), and S. boydii (5%). Over 90% of all Shigella isolates were resistant to trimethoprim-sulfamethoxazole and sulfisoxazole. Additional resistance included nalidixic acid (3%), ciprofloxacin (1%) and ceftriaxone (1%). Conclusion: More than 1 of every 200 persons experience shigellosis each year in this Kenyan urban slum, yielding rates similar to those in some Asian countries. Provision of safe drinking water, improved sanitation, and hygiene in urban slums are needed to reduce disease burden, in addition to development of effective Shigella vaccines.
Dynamic Recrystallization (DRX) as the Mechanism for Sn Whisker Development. Part I: A Model

A model is proposed that attributes whisker growth in metals and alloys to dynamic recrystallization (DRX) and, in particular, DRX at the material surface. Each step in the DRX process was correlated to the development of whiskers. The DRX model depends upon the details of the deformation process(es) responsible for new grain initiation and growth. The dependencies exhibited by DRX as a function of deformation strain rate, temperature, and microstructure correlate with the behaviors of whisker development. Anomalous or ultrafast diffusion mechanisms, either by themselves or associated with the deformation structures, provide the means of mass transport necessary to grow whiskers. In Part II of this study, the strain and rate kinetics data are determined for Sn. Parts I and II, together, provide a critical step towards developing a capability to predict the conditions that are likely to cause whisker growth in engineering applications.
Sobre justiça: lições de Platão, Rawls e Ishiguro

Nesse ensaio, Fraser elabora uma reflexao sobre a justica a partir dos escritos de Platao, Rawls e Ishiguro. Por meio de uma analise critica de Nao me abandone jamais, Fraser procura extrair do romance de Ishiguro proposicoes praticas para nossa realidade cotidiana. Segundo a autora, uma sociedade justa deve desconstruir mecanismos sociais excludentes que, ao restringir o âmbito dos sujeitos de justica a apenas um grupo social, impedem o tratamento equânime de todas as pessoas.
Towards Large-Scale, Human-Based, Mesoscopic Neurotechnologies

Direct human brain recordings have transformed the scope of neuroscience in the past decade. Progress has relied upon currently available neurophysiological approaches in the context of patients undergoing neurosurgical procedures for medical treatment. While this setting has provided precious opportunities for scientific research, it also has presented significant constraints on the development of new neurotechnologies. A major challenge now is how to achieve high-resolution spatiotemporal neural recordings at a large scale. By narrowing the gap between current approaches, new directions tailored to the mesoscopic (intermediate) scale of resolution may overcome the barriers towards safe and reliable human-based neurotechnology development, with major implications for advancing both basic research and clinical translation.
Preburn Psychiatric History Affects Posttrauma Morbidity

A sample of inpatient, burn-injured adults (N = 95) were assessed upon discharge, and 4 and 12 months later with a structured interview and DSM-III-R criteria. The prevalence of disorder in this sample was contrasted with published data on a representative national community-dwelling comparison group in the National Comorbidity Study. The prevalence of lifetime affective, alcohol, and substance use disorders was significantly higher, and lifetime anxiety disorders significantly lower, in the burn-injured sample. The 12-month postburn prevalences of alcohol, and substance use disorders were significantly greater in the burn-injured sample. The risk of postburn disorder was significantly greater for the subjects who had a preburn history of affective, alcohol, or substance use disorder. The risk for developing posttraumatic stress disorder (PTSD) was elevated in the subjects with a preburn affective disorder but not preburn anxiety disorder. Finally, postburn PTSD was associated with a greater length of stay, and greater preburn comorbidity predicted preburn employment status and tended to lengthen hospitalization.
Determination of Low-Energy Cutoffs and Total Energy of Nonthermal Electrons in a Solar Flare on 2002 April 15

The determination of the low-energy cutoff to the spectrum of accelerated electrons is decisive for the estimation of the total nonthermal energy in solar flares. Because thermal bremsstrahlung dominates the low-energy part of flare X-ray spectra, this cutoff energy is difficult to determine with spectral fitting alone. We have used anew method that combines spatial, spectral, and temporal analysis to determine the cutoff energy for the M1.2 flare observed with RHESSI on 2002 April 15. A low-energy cutoff of 24 +/- 2 keV is required to ensure that the assumed thermal emissions always dominate over nonthermal emissions at low energies (<20 keV) and that the spectral fitting results are consistent with the RHESSI light curves and images. With this cutoff energy, we obtain a total nonthermal energy in electrons of (1.6 +/- 1) x 10(exp 30) ergs that is comparable to the peak energy in the thermal plasma, estimated from RHESSI observations to be (6 +/- 0.6) x 10(exp 29) ergs assuming a filling factor of 1.
What can dependence theories tell us about assessing the emergence of tobacco dependence

Little is known about the processes that underlie changes in smoking that occur between the first use of a cigarette, subsequent regular use and eventual addictive use. At present, assessments of those critical processes are poorly developed and not strongly informed by contemporary models of drug dependence. The preceding three papers in this special issue address explicitly how modern drug-dependence theories describe the emergence of drug dependence and the implications of those theories for assessment. The papers covered three domains of theories: negative reinforcement, positive reinforcement, and cognitive and social learning. In this paper, we summarize these reviews and extract general themes and issues that emerge across all the articles. These include: (1) the importance of learning processes; (2) limitations of self-report measures; (3) the view of dependence as a process and not a state; (4) the conception of dependence on a continuum in contrast to the conventional perspective of tobacco dependence as a natural category; (5) the ontological status of the dependence concept; (6) limitations of backward extrapolations from adult assessments; (7) the possibility of multiple dimensions or forms of dependence; and (8) the value of a transdisciplinary approach when studying the emergence of tobacco dependence.
Clarkforkian Land-Mammal Age: Revised Definition, Zonation, and Tentative Intercontinental Correlations

New faunal and stratigraphic evidence documents the validity of the North American Clarkforkian Land-Mammal Age. Its limits are defined by the initial appearances of immigrant taxa. In the type area (northwestern Wyoming), the Clarkforkian is subdivided into three zones. Clarkforkian faunas are approximately correlative with latest Paleocene-earliest Eocene faunas of the Paris Basin of Europe and in part with the Gashato-Naran Bulak faunas of Mongolia.
A methodology for designing proof rules for fair parallel programs

We propose a methodology for designing sound and complete proof systems for proving progress properties of parallel programs under various fairness assumptions. Our methodology begins with a branching time temporal logic formula (CTL*) formula that expresses progress under a fairness assumption. The next step obtains an equivalent fixpoint characterization of this CTL* formula in theμ-calculus. The final step uses the fixpoint characterizations to extract proof systems for proving progress under the fairness constraint. The methodology guarantees that the proof rules so obtained are sound and relatively complete in the sense of Cook.
Oxidative stress and apoptosis

Apoptosis or programmed cell death, is essential for the normal functioning and survival of most multi-cellular organisms. The morphological and biochemical characteristics of apoptosis, however, are highly conserved during the evolution. It is currently believed that apoptosis can be divided into at least three functionally distinct phases, i.e. induction, effector and execution phase. Recent studies have demonstrated that reactive oxygen species (ROS) and the resulting oxidative stress play a pivotal role in apoptosis. Antioxidants and thiol reductants, such as N-acetylcysteine, and overexpression of manganese superoxide (MnSOD) can block or delay apoptosis. Bcl-2, an endogenously produced protein, has been shown to prevent cells from dying of apoptosis apparently by an antioxidative mechanism. Taken together ROS, and the resulting cellular redox change, can be part of signal transduction pathway during apoptosis. It is now established that mitochondria play a prominent role in apoptosis. During mitochondrial dysfunction, several essential players of apoptosis, including pro-caspases, cytochrome C, apoptosis-inducing factor (AIF), and apoptotic protease-activating factor-1 (APAF-1) are released into the cytosol. The multimeric complex formation of cytochrome C, APAF-1 and caspase 9 activates downstream caspases leading to apoptotic cell death. All the three functional phases of apoptosis are under the influence of regulatory controls. Thus, increasing evidences provide support that oxidative stress and apoptosis are closely linked physiological phenomena and are implicated in pathophysiology of some of the chronic diseases including AIDS, autoimmunity, cancer, diabetes mellitus, Alzheimer's and Parkinson's and ischemia of heart and brain.
Human natural killer cell development in secondary lymphoid tissues

For nearly a decade it has been appreciated that critical steps in human natural killer (NK) cell development likely occur outside of the bone marrow and potentially necessitate distinct microenvironments within extramedullary tissues. The latter include the liver and gravid uterus as well as secondary lymphoid tissues such as tonsils and lymph nodes. For as yet unknown reasons these tissues are naturally enriched with NK cell developmental intermediates (NKDI) that span a maturation continuum starting from an oligopotent CD34+CD45RA+ hematopoietic precursor cell to a cytolytic mature NK cell. Indeed despite the detection of NKDI within the aforementioned tissues, relatively little is known about how, why, and when these tissues may be most suited to support NK cell maturation and how this process fits in with other components of the human immune system. With the discovery of other innate lymphoid subsets whose immunophenotypes overlap with those of NKDI, there is also need to revisit and potentially re-characterize the basic immunophenotypes of the stages of the human NK cell developmental pathway in vivo. In this review, we provide an overview of human NK cell development in secondary lymphoid tissues and discuss the many questions that remain to be answered in this exciting field.
Tidal Migrations of Nekton in Salt Marsh Intertidal Creeks

Salt marsh intertidal creeks are important habitats for dozens of species of nekton, but few studies have attempted to quantify patterns of tidal movement. We used the sweep flume, a new sampling device, to investigate relationships between depth and movements of nekton inside the mouths of intertidal creeks. Sweep flumes located in three creek beds were used to collect nekton at 10 cm increments (10-100 cm of water depth) during flood and ebb tides in the North Inlet, South Carolina, salt marsh. Of the 37 taxa collected, 13 comprised >99.5% of the total catch and were the focus of the analysis. A nonlinear mixed modeling procedure was used to determine the depth at which each major taxon reached peak abundance during flood tides. With high degrees of spatial and temporal consistency, resident taxa entered early on the rising tide and transient taxa entered during mid to late tide. Depths of peak migrations varied among taxa and were consistent between creeks, days (within months), and years. As summer progressed, depths of peak migration increased for young-of-the-year Leiostomus xanthurus, Lagodon rhomboides, Mugil curema, Eucinostomus argenteus, and Litopenaeus setiferus as their median sizes increased. Within tides, depths of migration increased as a function of size for L. xanthurus and M. curema. Comparisons between flood and ebb tides indicated that most taxa exited the creeks at approximately the same depths at which they entered. Relationships between major taxa pairs suggested that biotic interactions may have contributed to the structure of the migrations observed in this study. Our results are the first to demonstrate quantitatively that the migrations of nektonic taxa into intertidal creeks are structured and related to depth.
Abstract P4-06-10: Altered Activity of RhoA and RhoC GTPases Phosphorylate C-Jun N-Terminal Kinase and Induce Cellular Dormancy in Breast Cancer Cells

Tumor dormancy has been a very real problem in breast cancer survivors where recurrences are common and usually fatal. Molecular mechanisms involved in this process are often poorly understood and are a “hot-spot” in breast cancer research today. Ongoing efforts in our laboratory has shown that Rho GTPases, specifically RhoA and RhoC, play a significant role in dormancy of breast cancer. We have currently established two in vitro models of breast tumor dormancy — one involving growth of the breast cancer cell line MCF7 on fibronectin and subsequent treatment with basic fibroblast growth factor and the other involving treatment of MCF7 cells with the farnesyl transferase inhibitor FTI-L-744,832. In both these models, we find high levels of active RhoC and almost undetectable levels of active RhoA GTPases in quiescent breast tumor cells. Investigating further downstream we found c-jun N-terminal kinase (JNK) is phosphorylated in these dormant cells but not p38mitogen activated protein kinase(MAPK) or extracellular signalregulated kinase(ERK1/2). On inhibiting JNK with a pharmacological inhibitor specific for JNK, SP600125, we found dormancy could be interrupted and cell proliferation was induced. JNK has been implicated in inducing autophagy in cells by activating autophagy gene Atg5 and Beclin1 (BCN1) [Byun et al., Carcinogenesis, 2009]. Since autophagy can be a mode of survival for the dormant tumor cell [Matthew et al., Cancer Cell, 2006] we explored the possibility of autophagy being induced in these dormant tumor cells via JNK by employing the autophagy marker LC3-II. We found upregulation of the autophagy marker, thus revealing autophagy as a strategy for survival for these tumor cells in unfavorable tumor microenvironment. We are currently investigating the molecular mechanisms underlying the induction of dormancy in breast tumor cells by Rho GTPases through JNK and the dormant tumor survival strategy through autophagy. We believe that targeting these implicated molecules like RhoA and RhoC GTPases, JNK or some of the autophagy genes might yield therapeutic benefits for breast cancer patients in remission and wipe out fears of deadly metastatic recurrences thus prolonging survival. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-06-10.
Assessing mobility and redistribution patterns of sand and oil agglomerates in the surf zone.

Abstract Heavier-than-water sand and oil agglomerates that formed in the surf zone following the Deepwater Horizon oil spill continued to cause beach re-oiling 3 years after initial stranding. To understand this phenomena and inform operational response now and for future spills, a numerical method to assess the mobility and alongshore movement of these “surface residual balls” (SRBs) was developed and applied to the Alabama and western Florida coasts. Alongshore flow and SRB mobility and potential flux were used to identify likely patterns of transport and deposition. Results indicate that under typical calm conditions, cm-size SRBs are unlikely to move alongshore, whereas mobility and transport is likely during storms. The greater mobility of sand compared to SRBs makes burial and exhumation of SRBs likely, and inlets were identified as probable SRB traps. Analysis of field data supports these model results.
Atmospheric CO2 enrichment increases growth and photosynthesis of Pinus taeda: a 4 year experiment in the field

Forest trees are major components of the terrestrial biome and their response to rising atmospheric CO 2 plays a prominent role in the global carbon cycle. In this study, loblolly pine seedlings were planted in the field in recently disturbed soil of high fertility, and CO 2 partial pressures were maintained at ambient CO 2 (Amb) and elevated CO 2 (Amb + 30 Pa) for 4 years. The objective of the study was to measure seasonal and long-term responses in growth and photosynthesis of loblolly pine exposed to elevated CO 2 under ambient field conditions of precipitation, light, temperature and nutrient availability. Loblolly pine trees grown in elevated CO 2 produced 90% more biomass after four growing seasons than did trees grown in ambient CO 2 . This large increase in final biomass was primarily due to a 217% increase in leaf area in the first growing season which resulted in much higher relative growth rates for trees grown in elevated CO 2 . Although there was not a sustained effect of elevated CO 2 on relative growth rate after the first growing season, absolute production of biomass continued to increase each year in trees grown in elevated CO 2 as a consequence of the compound interest effect of increased leaf area on the production of more new leaf area and more biomass. Allometric analyses of biomass allocation patterns demonstrated size-dependent shifts in allocation, but no direct effects of elevated CO 2 on partitioning of biomass. Leaf photosynthetic rates were always higher in trees grown in elevated CO 2 , but these differences were greater in the summer (60-130% increase) than in the winter (14-44% increase), reflecting strong seasonal effects of temperature on photosynthesis. Our results suggest that seasonal variation in the relative photosynthetic response to elevated CO 2 will occur in natural ecosystems, but total non-structural carbohydrate (TNC) levels in leaves indicate that this variation may not always be related to sink activity. Despite indications of canopy-level adjustments in carbon assimilation, enhanced levels of leaf photosynthesis coupled with increased total leaf area indicate that net carbon assimilation for the whole tree was greater for trees grown under elevated CO 2 compared with ambient CO 2 . If the large growth enhancement observed in loblolly pine were maintained after canopy closure, then these trees could be a large sink for fossil carbon emitted to the atmosphere and produce a negative feedback on atmospheric CO 2 .