cssi/SciSciGPT-SciSciNet huggingface dataset:
High-performance liquid chromatographic determinations of disaccharides resulting from enzymatic degradation of isomeric chondroitin sulfates.

Abstract The use of Whatman Partisil-10 PAC and Altex LiChrosorb NH 2 bonded phase columns for the high-performance liquid chromatographic separation of the disaccharides obtained from digestion of isomeric chondroitin sulfates with chondroitinases has been investigated. The substituted unsaturated disaccharides in the enzymatic degradation mixtures undergo rapid isocratic separations on both bonded stationary phases. A complete separation can be established within 10 min. The development of these procedures has expedited enzymatic studies of isomeric chondroitin sulfates. The rate of depolymerization of chondroitin sulfates by the action of chondroitinases based on quantitative high-performance liquid chromatographic separations and detection of the disaccharide products was studied.
PHYSIOLOGICAL AND HERITABLE CHANGES IN CYCLIC AMP LEVELS ASSOCIATED WITH CHANGES IN FLAGELLAR FORMATION IN CHLAMYDOMONAS REINHARDTII (CHLOROPHYTA)1

Synchronously dividing cells of Chlamydomonas reinhardtii Dang. (Chlorophyta) produce a single peak of cyclic adenosine monophosphate (cAMP), about sevenfold above the basal level, at the time of onset of the flagellar shortening that precedes mitosis. Cultures of a spontaneous palmelloid variant (which forms flagella-less cell clusters) of C. reinhardtii produce up to 15 times more cAMP per gram fresh weight of cells than do cultures of normal C. reinhardtii. Revertants from the palmelloid phenotype to the normal phenotype exhibit the low levels of cAMP characteristic of normal C. reinhardtii. Thus, elevation of cAMP level and decreased ability to form or maintain flagella are closely related phenomena. We propose that flagellar assembly/disassembly is regulated by endogenous cAMP in C. reinhardtii.
Seeing trends from deployable Shack-Hartmann wavefront sensors, MMT Observatory, Arizona, USA

Deployable Shack-Hartmann wavefront sensors (WFS) for the f/5 and f/9 secondary configurations have been used at the 6.5-meter MMT Observatory (MMTO) since 2003. Probe mirrors for these WFS's are moved into the optical path of the telescope between scientific observations multiple times each night. Results from the wavefront measurements are then used to bend the primary mirror (M1) and to reposition the secondary mirror (M2) to correct for wavefront errors. In addition to measuring the optical wavefront error, the Shack-Hartmann data are used to determine the delivered seeing using the measured spot sizes. This study attempts to analyze the more than 75,000 WFS measurements and associated seeing values obtained at the MMTO since 2003. The overall WFS data reduction and analysis procedure is discussed. This data analysis includes: 1) finding the spots in each image, 2) centroiding the spots, 3) measuring a point-spread function, 4) determining an average spot width and a derived seeing value, and 5) computing the best-fit Zernike polynomial coefficients. Wavefront slopes are calculated from spot displacements and wavefront aberrations are fit with a 19-term Zernike polynomial. As part of this study, the WFS-derived seeing values are correlated with other observing parameters, such as mirror-air temperature contrasts. Finally, seasonal climate and local weather (e.g., prevailing wind direction) effects on astronomical seeing are evaluated.
An adjustment for a test concerning a principal component subspace

Abstract A Bartlett adjustment factor is obtained for a statistic used to test the hypothesis that a specified set of m orthonormal vectors spans the same subspace as does the set of the first m principal component vectors. The adjusted and unadjusted statistics are compared via a simulation study.
Antinociceptive effects of the selective delta opioid agonist SNC80 alone and in combination with mu opioids in the squirrel monkey titration procedure.

Abstract Rationale. The nonpeptidic compound SNC80 [(+)-4[(αR)-α-((2S, 5R)-4-allyl-2, 5,-dimethyl-l-piperazinyl)-3-methoxybenzyl]-N,N-diethylbenzamide], has a high degree of selectivity for delta opioid receptors. Moreover, compounds with delta opioid activity have been shown to enhance the effects of mu agonists under certain conditions. Objectives. The present study examined the effects of SNC80 alone and in combination with the mu opioid agonists, morphine, butorphanol, and buprenorphine to determine whether SNC80 would enhance their antinociceptive effects. Methods. In the squirrel monkey shock titration procedure increasing levels of shock are delivered to the monkey's tail in incremental steps and responses on a lever decrease shock intensity. The level at which monkeys maintain the shock (median shock level, MSL) and rate of responding (RR) are examined. Results. SNC80 alone did not consistently alter responding under the titration procedure; however, morphine, butorphanol, and buprenorphine increased MSL without decreasing RR markedly. SNC80 (0.1–3.0 mg/kg) enhanced the effects of single doses of morphine, butorphanol, and buprenorphine that either did not increase or produced very small increases in MSL when administered alone. Interestingly, SNC80 enhanced the effects of morphine, butorphanol, and buprenorphine on MSL without decreasing RR. Conclusions. SNC80 does not produce antinociceptive effects in the squirrel monkey titration procedure but can enhance the effects of selected doses of morphine, butorphanol, and buprenorphine on MSL without decreasing RR. These data suggest that SNC80-induced enhancement of the antinociceptive effects of mu opioids is dependent on dose, time, and method of administration and is not the result of sedation or motor dysfunction.
Multiprocessors and computer networks

In this brief note, I would like to review the histories of computer networking and multiprocessor architecture and suggest ways in which these two streams of research are flowing back together and enriching each other. One can view both fields of research as departures from an original von Neumann computer organization consisting of a central processing unit (CPU) acting on data in a main memory and interacting with the outside world through peripheral devices.
Redefining automatic target recognition (ATR) performance standards

Present descriptors for Automatic Target Recognition (ATR) performance are inadequate for use in comparing algorithms that are purported to be a solution to the problem. The use of receiver operator characteristic curves (ROCs) is a defacto standard, but they do not communicate several key performance measures, including (i) intrinsic separation between classes in the input space, (ii) the efficacy of the mapping induced by the algorithm, (iii) the complexity of the algorithmic mapping, and (iv) a measure of the generalization of the proposed solution. Previous work by Sims et. al. 2,5 has addressed the distortion of the evaluation sets to indicate an algorithm's capability (or lack thereof) for generalization and handling of unspecified cases. This paper addresses the rethinking of the summary statistics used for understanding the performance of a solution. We propose new approaches for solution characterization, allowing algorithm performance comparison in an equitable and insightful manner. This paper proffers some examples and suggests directions for new work from the community in this field.
Near-infrared fluorescent probes

The application of near-infrared molecules as potential probes for fiber optic applications is discussed. A bis-carboxylic acid derivative of a carbocyanine dye was utilized to determine solution pH changes, and a 2,3-dicyanonaphthalene derivative was used as a probe for the metal concentration studies. The absorbance and fluorescence wavelength of the NIR dyes used in the optical probe are above the 700 nm to minimize interference. The probe dye was entrapped in a polymer matrix attached at the distal end of two optical fibers. The output of a 780 nm semiconductor laser diode beam was focused on one fiber and used for excitation of the probe dye. The second fiber was used to collect the fluorescence from the probe. The fluorescence intensity was monitored as the probe was placed in vials containing the analyte. The optical probe response was found to be about 20 sec during the metal ion measurements; however, the probe response was shorter for pH measurements. The long term stability of the probe was investigated by a week-long period of observation and resulted in a change of about 2% in intensity signal, indicating suitable long term stability.
Opioid Use After Fracture Surgery Correlates With Pain Intensity and Satisfaction With Pain Relief

Background In 2012, Medicare began to tie reimbursements to inpatient complications, unplanned readmissions, and patient satisfaction, including satisfaction with pain management.
Film condensation along an inclined surface in a porous medium

Abstract The problems of steady film condensation outside a wedge or a cone embedded in a porous medium filled with a dry saturated vapor are investigated. As in classical film condensation problems, it is assumed that (a) the condensate and the vapor are separated by a distinct boundary with no two-phase zone in between, and (b) the condensate has constant properties. Within the boundary layer approximations, similarity solutions have been obtained for the temperature and flow fields in the condensate. Moreover, a closed form solution has been obtained for the Nusselt number which depends on the square root of the Rayleigh number and the dimensionless film thickness. The latter is found to be a function of a dimensionless parameter related to the degree of wall subcooling. Asymptotic cases for small and large wall subcoolings are also considered. As in the classical film condensation problems, it is found that the ‘Nusselt’-type approximation (for small wall subcooling) overestimates the film thickness while underestimates the Nusselt number. An approximate expression for Nusselt number in terms of the degree of wall subcooling explicitly is also obtained.
On the conditioning of random subdictionaries

Abstract An important problem in the theory of sparse approximation is to identify well-conditioned subsets of vectors from a general dictionary. In most cases, current results do not apply unless the number of vectors is smaller than the square root of the ambient dimension, so these bounds are too weak for many applications. This paper shatters the square-root bottleneck by focusing on random subdictionaries instead of arbitrary subdictionaries. It provides explicit bounds on the extreme singular values of random subdictionaries that hold with overwhelming probability. The results are phrased in terms of the coherence and spectral norm of the dictionary, which capture information about its global geometry. The proofs rely on standard tools from the area of Banach space probability. As an application, the paper shows that the conditioning of a subdictionary is the major obstacle to the uniqueness of sparse representations and the success of l 1 minimization techniques for signal recovery. Indeed, if a fixed subdictionary is well conditioned and its cardinality is slightly smaller than the ambient dimension, then a random signal formed from this subdictionary almost surely has no other representation that is equally sparse. Moreover, with overwhelming probability, the maximally sparse representation can be identified via l 1 minimization. Note that the results in this paper are not directly comparable with recent work on subdictionaries of random dictionaries.
On the estimation of climatological Z-R relationships

A statistical framework for climatological Z-R parameter estimation is developed and simulation experiments are conducted to examine sampling properties of the estimators. Both parametric and nonparametric models are considered. For parametric models, it is shown that Z-R parameters can be estimated by maximum likelihood, a procedure with optimal large sample properties. A general nonparametric framework for climatological Z-R estimation is also developed. Nonparametric procedures are attractive because of their flexibility in dealing with certain types of measurement errors common to radar data. Simulation experiments show that even under favorable assumptions on error characteristics of radar and raingages, large datasets are required to obtain accurate Z-R parameter estimates. Another important conclusion is that estimation results are generally quite sensitive to radar and raingage measurement thresholds. For fixed sample size, the simulation results can be used to provide quantitative assessments of the accuracy of Z-R model parameter estimates. These results are particularly useful for error analysis of precipitation products that are derived using climatological Z-R relations. One example is the large-area rainfall estimates derived using the height-area rainfall threshold (HART) technique.
Coherent knowledge structure and theory‐based approach to categorization

How we understand our surroundings is an age old question. The general understanding is that it is through concepts, categories, and relations that we make sense of our world. This study presents a result of a dissertation that attempted to investigate the nexus between human cognition of concepts/categories and the knowledge structure in the unified medical language system (UMLS). In contrast to the classical account that views category as structures organized in terms of similarity, this study takes a new approach that explains categories as structures organized around theories. The findings reveal that humans largely use simplified rules, definition type descriptions, and naive explanations as bases for categorization judgment (coherence criteria). These explanations research participants used to characterize their category formation, after a careful text analysis, created meaningful and coherent interrelationships when plotted in a visual link chart. The performance of the cognitive task also showed a remarkable difference between those with subject background and those without. Using the least restrictive notion of ‘distance’ as a function of relatedness, this study also showed a significant correspondence between human conceptual map (based on the cognitive performance) and the knowledge structure in the UMLS, as shown by the goodness-of-fit coefficient.
Outcomes of Donor Hearts Offered for Transplantation, Declined by a Single Center and Transplanted at a Secondary Institution

Background: Many predictors to assess risk of heart failure (HF) readmissions have been suggested, yet a broad-based approach to using models is lacking. The purpose of this analysis was to use clinical predictors for readmissions found in a univariate analysis in an urban, tertiary care center to create and propose a clinically useful model for HF readmissions derived from a multivariate analysis. Methods: The enterprise data warehouse and the database registry of the Intermountain Heart Collaborative Study were queried for patients discharged from Intermountain Medical Center with a primary diagnosis of HF between January 1, 2012 and December 31, 2012. Assessment of 30-day all-cause (AC) readmissions extended through January 31, 2013. Patients were grouped into those who were, or were not, readmitted within 30 days of discharge. In a previous parallel study, we considered 71 variables in a univariate analysis, 25 of which reached statistical significance for readmissions. Themes from these variables included demographic and clinical data, clinical treatments, comorbidities, and measures of acuity. These variables were then used to perform a multivariate logistic regression analysis to create a risk prediction model for 30-day AC readmissions. Results: Of 586 eligible HF patients identified, 103(17.6%) were readmitted within 30-days; mean time to readmission 13.5 days ( 8.7). The multivariate analysis resulted in 5 variables that remained significant and were predictive of 30-day AC readmissions: longer length of stay, other admissions within the prior year, lower systolic blood pressure on admission, use of pressors or inotropes, and ever having a diagnosis of pneumonia. The final model showed good discrimination for 30-day all-cause readmission with an area under the curve c-statistic of 0.75, see Figure. Conclusions: Given national pressures to improve HF care and reduce readmissions, assessing variables associated with an increased risk in a meaningful manner is not only timely, but of clinical importance. Defining areas of higher acuityseen in longer lengths of stay and previous hospital encounters -should trigger heightened awareness of risk. Creating useful predictive models that may be tested and validated in larger populations will be the next step in making a difference in HF care.
Impact of Valvular Regurgitation and Ventricular Dysfunction on Long-Term Survival in Patients With Chest Pain

Abstract Doppler echocardiography is often used in evaluating patients with chest pain, but information on prognostic value of this testing and data to help guide selective use are limited. We prospectively studied 448 patients admitted from the emergency department for acute chest pain to assess the utility of qualitative echocardiographic data in predicting long-term survival and the incremental value of this information over routine clinical and electrocardiographic data. Doppler echocardiograms, recorded an average of 21 hours after presentation, were analyzed independently by 2 echocardiographers for global left and right ventricular function and valvular disease. Regional function was assessed by wall motion index. Data on long-term survival were collected with an average follow-up of 35.0 ± 12.1 months. In univariate Cox regression analysis, left ventricular function and size, wall motion index, right ventricular function, and aortic, mitral, and tricuspid insufficiency were significant predictors of total and cardiovascular mortality. In multivariate analysis, moderate or severe left ventricular dysfunction (mortality rate ratio 3.2, 95% confidence intervals 1.8 to 5.8] and more than mild valvular regurgitation (mortality rate ratio 2.0, 95% confidence interval 1.1 to 3.6) were independent predictors of mortality in a model adjusted for clinical and electrocardiographic data. These factors were more common in patients aged >60 years, in those with prior acute myocardial infarction or angina, and in those with rales on physical examination. In the absence of these clinical characteristics, only 8 of 124 patients (7%) had moderate or severe left ventricular dysfunction or valvular regurgitation. In patients with moderate or severe regurgitation, a murmur was noted on the admission physical examination in 41 of 69 cases (59%). We conclude that echocardiographic evidence of moderate or severe left ventricular dysfunction or valvular regurgitation identifies a high-risk group for overall and cardiovascular mortality in patients with chest pain, and this evidence may not be detected clinically.
Functional and cytoarchitectural spinal cord protection by ATL-146e after ischemia/reperfusion is mediated by adenosine receptor agonism

Background ATL-146e protects the spinal cord from ischemia/reperfusion injury, presumably via adenosine A 2A receptor activation, but this relationship remains unproven. We hypothesized that spinal cord functional and cytoarchitectural preservation from ATL-146e would be lost with simultaneous administration of the specific adenosine A 2A antagonist ZM241385 (ZM), thus proving that adenosine A 2A receptor activation is responsible for the protective effects of this compound. Methods New Zealand White rabbits underwent 45 minutes of infrarenal aortic cross-clamping. Groups (n = 10) included sham, ischemia, ischemia plus ATL-146e (ATL-146E), ischemia plus ZM, or ischemia with both compounds (agonist-antagonist). Tarlov scores were recorded every 12 hours. After 48 hours, the spinal cord was fixed for histology and microtubule-associated protein 2 immunohistochemistry. Results Tarlov scores at 48 hours were significantly better in the sham and ATL-146E groups (5.0 and 3.9, respectively) compared with the other three groups (all ≤1.3; P P Conclusions ATL-146e preserves the spinal cord in terms of both cytoarchitecture and function after reperfusion of the ischemic spinal cord, but this preservation is not completely blocked by competitive adenosine A 2A receptor antagonism. Although ATL-146e does seem to partially function through activation of the adenosine A 2A receptor, the neuroprotective mechanism may not be limited to this particular receptor.
Sports, joint injury, and posttraumatic osteoarthritis.

Participation in sports increases the risk of joint injuries that can lead to posttraumatic osteoarthritis, a clinical syndrome caused by trauma-initiated joint degeneration that results in permanent and often progressive joint pain and dysfunction. Minimizing the risk of joint injuries and helping people with osteoarthritis participate in regular physical activity, including some sports, requires understanding of the relationships between joint use, joint injury, and joint degeneration. Lifelong participation in sports that cause minimal joint impact and torsional loading by individuals with normal joints and neuromuscular function does not increase the risk of posttraumatic osteoarthritis. In contrast, participation in sports that subject joints to high levels of impact and torsional loading increases the risk of joint injury and subsequent joint degeneration. Immediate diagnosis and appropriate treatment and rehabilitation following joint injuries decrease the risk of subsequent injuries and posttrauma...
Defining the critical-sized defect in a rat segmental mandibulectomy model.

Importance Advances in tissue engineering offer potential alternatives to current mandibular reconstructive techniques; however, before clinical translation of this technology, a relevant animal model must be used to validate possible interventions. Objective To establish the critical-sized segmental mandibular defect that does not heal spontaneously in the rat mandible. Design and Setting Prospective study of mandibular defect healing in 29 Sprague-Dawley rats in an animal laboratory. Interventions The rats underwent creation of 1 of 4 segmental mandibular defects measuring 0, 1, 3, and 5 mm. All mandibular wounds were internally fixated with 1-mm microplates and screws and allowed to heal for 12 weeks, after which the animals were killed humanely. Main Outcomes and Measures Analysis with micro–computed tomography of bony union and formation graded on semiquantitative scales. Results Seven animals were included in each experimental group. No 5-mm segmental defects successfully developed bony union, whereas all 0- and 1-mm defects had continuous bony growth across the original defect on micro–computed tomography. Three of the 3-mm defects had bony continuity, and 3 had no healing of the bony wound. Bone union scores were significantly lower for the 5-mm defects compared with the 0-, 1-, and 3-mm defects ( P Conclusions and Relevance The rat segmental mandible model cannot heal a 5-mm segmental mandibular defect. Successful healing of 0-, 1-, and 3-mm defects confirms adequate stabilization of bony wounds with internal fixation with 1-mm microplates. The rat segmental mandibular critical-sized defect provides a clinically relevant testing ground for translatable mandibular tissue engineering efforts.
Generic bifurcation with application to the von Kármán equations

Abstract We examine the possible types of generic bifurcation than can occur for a three-parameter family of mappings from a Banach space into itself. Specifically, the general form of the bifurcation equations arising from the von Karman equations for the buckling of a rectangular plate is investigated. Chow, Hale, and Mallet-Paret (Applications of generic bifurcation. II, Arch. Rational Mech. Anal. 67 (1976)) studied the bifurcation of solutions to these equations in a two-parameter setting. These parameters were related to the normal loading and to the compressive thrust applied at the ends of the plate. We introduce a third bifurcation parameter by considering the length of the plate as variable. The generic hypotheses of Chow et al. no longer apply in this three-parameter setting, but modifications and extensions of these hypotheses permit a characterization of the three-parameter bifurcation diagram. The bifurcation sheets of this diagram appear as a natural generalization of the finite collection of arcs comprising the two-parameter diagram. As an example of this theory, an actual three-parameter bifurcation diagram is constructed for a specific form of the von Karman equations.
Technique of stereotactic biopsy in a 5-month-old child

We describe a technique of stereotactic frame-based biopsy in young children who have open fontanels and a deformable skull. A 5-month-old girl with a growing lesion in the right thalamus and basal ganglia underwent stereotactic biopsy, which disclosed an anaplastic astrocytoma. To avoid insertion of the four stereotactic frame fixation pins through the infant's skin and into bone, the pins were advanced into the hollowed end of rubber tops obtained from Vacutainer blood sampling tubes. The pressure applied to the skin was diffused through the rubber onto a wide skin surface, obviating skin puncture or bone deformation. This technique provided firm head fixation, and target accuracy was confirmed on post-operative imaging. This technique is safe and should permit use of conventional stereotactic techniques in young infants.
Parallel feedback pathways in visual cortex of cats revealed through a modified rabies virus.

The visual cortex of cats is highly evolved. Analogously to the brains of primates, large numbers of visual areas are arranged hierarchically and can be parsed into separate dorsal and ventral streams for object recognition and visuospatial representation. Within early primate visual areas, V1 and V2, and to a lesser extent V3, the two streams are relatively segregated and relayed in parallel to higher order cortex, although there is some evidence suggesting an alignment of V2 and V3 to one stream over the other. For cats, there is no evidence of anatomical segregation in areas 18 and 19, the analogs to V2 and V3. However, previous work was only qualitative in nature. Here we re-examined the feedback connectivity patterns of areas 18/19 in quantitative detail. To accomplish this, we used a genetically modified rabies virus that acts as a retrograde tracer and fills neurons with fluorescent protein. After injections into area 19, many more neurons were labeled in putative ventral stream area 21a than in putative dorsal stream region posterolateral suprasylvian complex of areas (PLS), and the dendrites of neurons in 21a were significantly more complex. Conversely, area 18 injections labeled more neurons in PLS, and these were more complex than neurons in 21a. We infer from our results that area 19 in cat is more aligned to the ventral stream and area 18 to the dorsal stream. Based on the success of our approach, we suggest that this method could be applied to resolve similar issues related to primate V3. J. Comp. Neurol. 520:988–1004, 2012. © 2011 Wiley Periodicals, Inc.
Plant-derived vaccines against diarrheal diseases

Transgenic plants present a novel system for both production and oral delivery of vaccine antigens. Production of protein antigen in food plants is substantially cheaper than production in bacterial, fungal, insect cell, or mammalian cell culture. Edible plants themselves can also serve as the oral vaccine delivery system. Phase-1 studies of raw transgenic potatoes expressing the B subunit of Escherichia coli heat labile enterotoxin (LT-B), potatoes expressing Norwalk virus capsid protein, and defatted corn germ meal expressing LT-B have been conducted. New oral vaccines based on other transgenic plants will soon be evaluated in humans.
2,3,7,8-tetrachlorodibenzo-p-dioxin increases the potency of androgens and estrogens as feedback inhibitors of luteinizing hormone secretion in male rats.

Abstract 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) decreases plasma androgen concentrations in male rats, without increasing plasma luteinizing hormone (LH) concentrations. If plasma LH concentrations had increased appropriately, plasma androgen concentrations in these animals would have returned to normal. The mechanism by which TCDD prevents the compensatory increase in plasma LH concentrations was therefore investigated. TCDD was found to have no effect on the plasma disappearance of iv administered LH. Therefore, the failure of plasma LH concentrations to rise was not due to increased clearance of LH from the circulation, but rather to an effect of TCDD on LH synthesis and/or secretion by the pituitary. In the absence of gonadal steroids (i.e., in castrated rats) TCDD did not prevent the compensatory increase in plasma LH concentrations from occurring. This was shown by 20-fold increases in plasma LH concentrations in both control and TCDD-treated rats 1 week after castration. Thus, (1) the presence of gonadal steroids is required for TCDD to prevent the compensatory increase in plasma LH concentrations, and (2) TCDD does not impair LH secretion by acting, itself, as an androgen or estrogen. TCDD treatment also did not affect pituitary LH content in castrated, testosterone-implanted rats. The above findings demonstrate that TCDD does not decrease the maximum rate at which the pituitary can synthesize and secrete LH. Rather, TCDD alters the feedback regulation of LH secretion when gonadal steroids are present. To determine if TCDD affects the potency of testosterone and its metabolites 5α-dihydrotestosterone and 17β-estradiol as feedback inhibitors of LH secretion, rats were dosed with TCDD, castrated, and implanted with sustained-release capsules containing graded amounts of each steroid. Seven days later, the potencies of all three hormones as feedback inhibitors of LH secretion were increased by TCDD, with little effect on their plasma concentrations. The TCDD dose dependence for the increased effectiveness of testosterone as a feedback inhibitor of LH secretion (ED50 10 μg/kg) was similar to that reported for the imbalance between plasma LH and androgen concentrations (ED50 15 μg/kg). Also, time courses for both responses were similar; each was detected within 1 day of TCDD dosing and each was fully developed after 7 days. We conclude that the mechanism by which TCDD prevents the compensatory increase in plasma LH concentrations in male rats is by increasing the potencies of androgens (and estrogens) as feedback inhibitors of LH secretion.
Using disposable polydimethylsiloxane fibers to assess the bioavailability of permethrin in sediment

Pyrethroid insecticides are widely used in both agricultural and urban environments. Pyrethroids have been frequently detected in California, USA, stream bed sediments. Pyrethroids are strongly hydrophobic so their bioavailability is determined by their sorption to sediment. In the present study, we used disposable polydimethylsiloxane (PDMS) fibers to sample from the freely dissolved (effective) permethrin concentration that governs bioaccumulation and toxicity, and tested the correlation of those measurements with uptake by Chironomus tentans. In sediments that were incrementally diluted with silica sand, both PDMS fiber and organic carbon (OC) normalized sediment concentrations were highly correlated with C. tentans permethrin uptake. However, for multiple sediments with OC ranging from 1.4 to 27%, C. tentans permethrin uptake showed a better correlation with PDMS fiber concentrations than sediment OC-normalized concentrations. We conclude that the qualitative properties of sediment OC influence permethrin phase distribution and therefore the bioavailability of permethrin in sediment-water systems. Consequently selective methods such as PDMS fibers yield improved estimates of bioaccumulation and toxicity as such methods detect freely dissolved permethrin concentrations in the sediment.
Snail2/Slug cooperates with Polycomb repressive complex 2 (PRC2) to regulate neural crest development

Neural crest cells arise from the border of the neural plate and epidermal ectoderm, migrate extensively and differentiate into diverse cell types during vertebrate embryogenesis. Although much has been learnt about growth factor signals and gene regulatory networks that regulate neural crest development, limited information is available on how epigenetic mechanisms control this process. In this study, we show that Polycomb repressive complex 2 (PRC2) cooperates with the transcription factor Snail2/Slug to modulate neural crest development in Xenopus. The PRC2 core components Eed, Ezh2 and Suz12 are expressed in the neural crest cells and are required for neural crest marker expression. Knockdown of Ezh2, the catalytic subunit of PRC2 for histone H3K27 methylation, results in defects in neural crest specification, migration and craniofacial cartilage formation. EZH2 interacts directly with Snail2, and Snail2 fails to expand the neural crest domains in the absence of Ezh2. Chromatin immunoprecipitation analysis shows that Snail2 regulates EZH2 occupancy and histone H3K27 trimethylation levels at the promoter region of the Snail2 target E-cadherin. Our results indicate that Snail2 cooperates with EZH2 and PRC2 to control expression of the genes important for neural crest specification and migration during neural crest development.
What Exactly Is a Youth Development Program? Answers From Research and Practice

The philosophy guiding youth development programs-that resilience and competency building are central to helping youth navigate adolescence in healthy ways-provides the groundwork for an exciting and promising array of programs for adolescents. Despite the number of programs or the importance of their objectives, whether they promote healthy adolescent development remains unclear because the definition of youth development programs is elusive and evolving. Drawing on both the literature and the results from a survey of highly regarded youth development programs, this article examines 3 defining characteristics of the youth development program-program goals, atmosphere, and activities. The results suggest a provisional definition of youth development programs based on the prevalent aspects of the goals, atmosphere, and activities reported by respondents. Youth development programs seek not only to prevent adolescents from engaging in health-compromising behaviors but to build their abilities and competenci...
Least absolute value and chebychev estimation utilizing least squares results

In exploratory data analysis and curve fitting in particular, it is often desirable to observe residual values obtained with different estimation criteria. The goal with most linear model curve-fitting procedures is to minimize, in some sense, the vector of residuals. Perhaps three of the most common estimation criteria require minimizing: the sum of the absolute residuals (least absolute value or L1 norm); the sum of the squared residuals (least squares or L2 norm); and the maximum residual (Chebychev or L∞ norm). This paper demonstrates that utilizing the least squares residuals to provide an advanced start for the least absolute value and Chebychev procedures results in a significant reduction in computational effort. Computational results are provided.
Actin in the parasite Toxoplasma gondii is encoded by a single copy gene, ACT1 and exists primarily in a globular form.

Actin is a highly conserved microfilament protein that plays an important role in the invasion of host cells by the protozoan parasite Toxoplasma gondii. We have characterized the ACT1 gene and localized the conventional isoform of actin that it encodes within T. gondii. The predicted amino acid sequence of ACT1 was most similar to two other parasite actins, Plasmodium falciparum Pfact-1 (93.1% identical) and Cryptosporidium parvum actin (88.1%): among vertebrate actins, ACT1 was most closely related to the mammalian β and γ (83%) actin isoforms. Actin-specific antibodies and fluorescently labeled DNAse I were used to localize actin in T. gondii tachyzoites by immunofluorescence and immunoelectron microscopy. Actin was detected beneath the parasite cell membrane and in clusters scattered within the cytosol of T. gondii tachyzoites. Actin filaments were not detected in detergent-solubilized parasites separated by high speed centrifugation, indicating that actin exists primarily in a globular form in T. gondii. Cell Motil. Cytoskeleton 37:253–262, 1997. © 1997 Wiley-Liss Inc.
Field Theory of Matter. II

A qualitative dynamical interpretation is given for observed regularities of nonleptonic phenomena in strong, electromagnetic, and weak interactions.
Distributed processing of biomass to bio-oil for subsequent production of Fischer-Tropsch liquids

This study compares centralized processing to distributed processing of biomass for subsequent produc- tion of Fischer-Tropsch liquids (FTLs) at a centralized catalytic synthesis facility. Distributed processing in this study is based on fast pyrolysis to bio-oils, which are more economically transported to a centralized F-T plant where bio-oil is gasifi ed and the syngas catalytically converted to FTLs. The study indicates that a centralized gasifi cation plant can produce FTLs from biomass for $1.56 per gallon of gasoline equivalent (gge) in an optimally sized plant of 550 million gge per year. Three distributed processing systems were investigated based on the scale of biomass processing capacity: 'on-farm' pyrolyzers of 5.4 ton per day (tpd) capacity; 'small cooperative' pyrolyzers of 55 tpd capacity, and 'large cooperative' pyrolyzers of 550 tpd capacity. Distributed processing is combined with very large centralized bio-oil processing plants that accept bio-oil for catalytic upgrading to transportation fuels, achieving costs as low as $1.43 for total fuel production capacities in excess of 2500 million gge. Total capital investment (distributed pyrolyzers and centralized bio-oil processing plant) for this optimally sized distributed processing system is projected to be $4 billion compared to $1.6 billion for the centralized biomass processing facility. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd
Comments on “Japan's Direct Manufacturing Investment”

(1990). Comments on “Japan's Direct Manufacturing Investment”. The Professional Geographer: Vol. 42, No. 2, pp. 223-226.
Effects of pipette modulation and imaging distances on ion currents measured with Scanning Ion Conductance Microscopy (SICM)

Local conductance variations can be estimated by measuring ion current magnitudes with scanning ion conductance microscopy (SICM). Factors which influence image quality and quantitation of ion currents measured with SICM have been evaluated. Specifically, effects of probe-sample separation and pipette modulation have been systematically studied for the case of imaging conductance variations at pores in a polymer membrane under transmembrane concentration gradients. The influence of probe-sample separation on ion current images was evaluated using distance-modulated (ac) feedback. Approach curves obtained using non-modulated (dc) feedback were also recorded to determine the relative influence of pipette-generated convection by comparison of ion currents measured with both ac and dc feedback modes. To better interpret results obtained, comparison to a model based on a disk-shaped geometry for nanopores in the membrane, as well as relevant position-dependent parameters of the experiment is described. These results advance our current understanding of conductance measurements with SICM.
Asthma morbidity and treatment in the Chicago metropolitan area: one decade after national guidelines

Background A number of studies have demonstrated disproportionate hospitalization and mortality rates in US urban areas. Yet, no published population-based studies have examined the burden of asthma on the residents of a particular urban area known to be at high risk for poor asthma outcomes. Objectives To examine asthma morbidity and medical care in a population-based sample of adults and children with asthma residing in the greater Chicago, IL, metropolitan area and to explore social and demographic influences on morbidity and treatment. Methods A telephone survey of adults living in the Chicago metropolitan area was conducted from November 1999 through December 2000. Results The final sample included 152 adults and children with active asthma. Emergency department visits and hospitalizations for asthma in the previous year were reported by 25.7% and 6.6% of respondents, respectively. Of current medication users, 32.2% reported current regular use of controller medications. After adjusting for age, sex, income, education, and reported current pharmacotherapy, compared with white individuals, African American individuals remained 6.3 times more likely to have experienced an emergency department visit and 12.3 times more likely to have been hospitalized. Conclusions These findings suggest that poorly controlled asthma remains a prevalent problem for persons with asthma in this metropolitan area and that a large gap remains between the goals of asthma therapy and appropriate treatment as defined by the National Asthma Education and Prevention Program. The reasons for disparate treatment and health outcomes by race/ethnicity and income need further study and intervention.
Who gets it? Engaging in action research in Zimbabwe

A tension exists between institutional requirements of reflective thinking among teachers and the realities of the classroom. The former is often ambiguous, complex, and difficult. Without laying much groundwork, there is little incentive for student teachers to take on such a challenge. This article offers four vignettes of student teachers' attempts at conducting action research in a Zimbabwean context. With minimal familiarity, preparation, and support, each student's success varied: one student completed the task without a deeper understanding; a second did not conduct much of the research; another was able to integrate the research process with his teaching practice; and the last student already possessed the skills and disposition needed to be successful. This article helps name some of the common enablers and obstacles to promoting reflexive thinking among student teachers. It starts first and foremost by establishing issues that need to be part of any dialogue on the meanings and ideals of action research in support of teaching in a development context.
The Role of Culture as Driver of Quality Management and Performance: Infrastructure Versus Core Quality Practices*

Increasingly, scholars and practitioners recognize the importance of understanding organizational culture when implementing operations management practices. This study investigates the relationships among organizational culture, infrastructure and core quality management practices, and manufacturing performance using two alternative models. Understanding these relationships is important because culture can provide insight into the context dependence of quality management practices and shed light on the mixed results of past studies concerning the link between quality management and performance. Analysis of manufacturing plants from six countries indicates that organizational culture has a stronger influence on infrastructure quality management practices than on core quality management practices, regardless of whether the plants are located in Eastern or Western countries. In addition, infrastructure quality management practices have a significant effect on manufacturing performance. These results contribute to the quality management literature by emphasizing the importance of accounting for culture when making decisions to implement quality management practices to achieve a performance advantage. Finally, we also contribute to the literature on the culture–performance linkage by finding support for a direct link between culture and manufacturing performance.
Computational analysis of gene-gene interactions using multifactor dimensionality reduction.

Understanding the relationship between DNA sequence variations and biologic traits is expected to improve the diagnosis, prevention and treatment of common human diseases. Success in characterizing genetic architecture will depend on our ability to address nonlinearities in the genotype-to-phenotype mapping relationship as a result of gene–gene interactions, or epistasis. This review addresses the challenges associated with the detection and characterization of epistasis. A novel strategy known as multifactor dimensionality reduction that was specifically designed for the identification of multilocus genetic effects is presented. Several case studies that demonstrate the detection of gene–gene interactions in common diseases such as atrial fibrillation, Type II diabetes and essential hypertension are also discussed.
The role of caspase-2 in stress-induced apoptosis

Caspase-2 is the most evolutionarily conserved of all the caspases, yet it has a poorly defined role in apoptotic pathways. This is mainly due to a dearth of techniques to determine the activation status of caspase-2 and the lack of an abnormal phenotype in caspase-2 deficient mice. Nevertheless, emerging evidence suggests that caspase-2 may have important functions in a number of stress-induced cell death pathways, in cell cycle maintenance and regulation of tumour progression. This review discusses recent advances that have been made to help elucidate the true role of this elusive caspase and the potential contribution of caspase-2 to the pathology of human diseases including cancer.
Systematic review of the predictive effect of MSI status in colorectal cancer patients undergoing 5FU-based chemotherapy

We systematically reviewed the evidence for the interaction of microsatellite instability status (MSI) and treatment with 5FU in colorectal cancer to determine how well MSI status predicts health outcomes in patients undergoing 5FU-based chemotherapy. We conducted a search of four electronic databases through June 2013. We considered studies that included both colorectal cancer patients treated with 5FU-based chemotherapy and untreated patients with survival outcomes presented by MSI status. We identified 16 studies for qualitative analysis (9,212 patients) with 14 studies eligible for meta-analysis. The microsatellite stable (MSS) group showed an effect of 5FU treatment on disease-free survival (HR of 0.62 [95% CI: 0.54, 0.71]) and overall survival (HR of 0.65 [95% CI: 0.54, 0.79]), indicating that MSS patients who received 5FU treatment had longer survival than MSS patients who were untreated. The effect of 5FU treatment was not statistically significant for microsatellite high (MSI-H) patients for disease-free survival (HR of 0.84 [95% CI: 0.53, 1.32]) or overall survival (HR 0.66 [95% CI: 0.43, 1.03]). However, the summarized point estimates of the effects of 5FU treatment for the MSS and MSI-H groups were not different at a statistically significant level. Our analyses indicate that treatment with 5FU-based chemotherapy improves disease-free and overall survival in CRC patients, but that there is no difference in the effect of treatment based on MSI status. Therefore, the use of MSI status to guide treatment decisions about the use of 5FU treatment for CRC has no significant benefits for patients.