cssi/SciSciGPT-SciSciNet huggingface dataset:
Biomaterials for spinal cord repair

Spinal cord injury (SCI) results in permanent loss of function leading to often devastating personal, economic and social problems. A contributing factor to the permanence of SCI is that damaged axons do not regenerate, which prevents the re-establishment of axonal circuits involved in function. Many groups are working to develop treatments that address the lack of axon regeneration after SCI. The emergence of biomaterials for regeneration and increased collaboration between engineers, basic and translational scientists, and clinicians hold promise for the development of effective therapies for SCI. A plethora of biomaterials is available and has been tested in various models of SCI. Considering the clinical relevance of contusion injuries, we primarily focus on polymers that meet the specific criteria for addressing this type of injury. Biomaterials may provide structural support and/or serve as a delivery vehicle for factors to arrest growth inhibition and promote axonal growth. Designing materials to address the specific needs of the damaged central nervous system is crucial and possible with current technology. Here, we review the most prominent materials, their optimal characteristics, and their potential roles in repairing and regenerating damaged axons following SCi.
Species richness and selenium accumulation of plants in soils with elevated concentration of selenium and salinity

Field studies were conducted in soils with elevated concentrations of Se and salinity at Kesterson, California. Biomass distribution, species richness, and selenium accumulation of plants were examined for two sites where 15 cm of surface soil was removed and replaced with fill dirt in the fall of 1989, and two sites were native soil cover. The Se concentrations in the top 15 cm of fill dirt ranged from undetectable to 36 ng g-1. For the native soil sites, Se levels ranged from 75 to 550 ng g-1. Soil Se concentrations below 15 cm ranged from 300 to 700 ng g-1 and were comparable between the fill dirt and the native soil sites. At least 20 different plant species were brought into the two fill dirt sites with the top soil. Avena fatua L., Bassia hyssopifolia Kuntze Rev. Gen. Pl., Centaurea solstitialis L., Erysimum officianale L., Franseria acanthicarpa Cav. Icon., and Melilotus indica (L.) All. contributed over 60% of the total biomass. Only 5 species were found in the native soil sites, and salt grass (Distichlis spicata L.) was the predominant species and accounted for over 80% of the total biomass. Between 1989 and 1990, two years after the surface soil replacement, the two fill dirt sites had a 70% reduction in species richness. Plant tissue selenium concentrations were found to be quite variable between plant species and between sites of sampling. At the fill dirt sites, the plant species with deep root systems accumulated greater amounts of selenium than the shallow-rooted species. The soil selenium concentration of the field soil had no negative effect on pollen fertility, seed set, and seed germination for the plant species examined. However, seedling growth was impaired by the soil selenium concentrations. This suggests that a selection pressure of soil Se concentration may have been imposed on plant species such as M. indica in an early stage of its life cycle.
Managing the Interpersonal Aspect of Performance Management

It is safe to assume that an accurate performance appraisal (PA) is an important prerequisite to an effective performance management (PM) system, because with accurate PA information, management, teams, and employees can engage in the process of identifying and developing a wide range of job-relevant knowledge or skills to improve job performance. However, researchers and practitioners alike must continue to push for PA to be something other an administrative ritual; the ideal goal for PA is for it to contribute to a reliable process that can offer practical help to organizational operations, including PM. As Pulakos, Mueller Hanson, Arad, and Moye (2015) have pointed out, supervisors are concerned about demotivating or disengaging employees by providing PA ratings that are too much lower than the highest rating or ranking that is available, so having ratings that are clustered at the high end of the rating scale is quite common across organizations (Bretz, Milkovich, & Read, 1992).
Cochlear implantation for children with GJB2-related deafness.

Objectives/Hypothesis: Mutations in GJB2 are a common cause of congenital sensorineural hearing loss. Many children with these mutations receive cochlear implants for auditory habilitation. The purpose of the study was to compare the speech perception performance of cochlear implant patients with GJB2-related deafness to patients without GJB2-related deafness. Study Design: Retrospective case review. Methods: Pediatric cochlear implant recipients who have been tested for GJB2 mutation underwent chart review. All patients received cochlear implantation at a tertiary referral center, followed by outpatient auditory habilitation. Charts were reviewed for cause and duration of deafness, age at time of cochlear implantation, intraoperative and postoperative complications, duration of use, and current age. Results of standard tests of speech perception administered as a part of the patients’ auditory habilitation were reviewed. Results: Twenty patients with GJB2 mutations were compared with 27 patients without GJB2 mutations. There was no statistical difference between patients with and without GJB2-related congenital sensorineural hearing loss with regard to openset and closed-set speech recognition performance at 12, 24, and 36 months after cochlear implantation. Surgical complications were uncommon. Conclusion: Pediatric patients with congenital sensorineural hearing loss without other comorbid conditions (eg, developmental delay, inner ear malformations) perform well when they receive cochlear implantation and auditory habilitation. The presence or absence of GJB2 mutation does not appear to impact speech recognition performance at 12, 24, and 36 months after implantation. Key Words: Connexin 26, GJB2, hearing loss, cochlear implant. Laryngoscope, 114:1415–1419, 2004
Analysis of the SH3-Binding Region of HIV-1 Nef: Partial Functional Defects Introduced by Mutations in the Polyproline Helix and the Hydrophobic Pocket

An SH3-binding domain within the Nef protein of primate lentiviruses has been reported to be important to viral replication and infectivity and dispensable for CD4 downregulation, but its precise role remains unclear. This study investigates the effects of mutations in both the polyproline helix and in the hydrophobic pocket that constitute the SH3-binding domain of Nef. The data demonstrate that the well-studied mutation of the central prolines is only partially disruptive to viral infectivity and replication. The central prolines also make a subtle contribution to the efficiency of CD4 downregulation, detectable only using low levels of Nef expression. Mutation of a conserved arginine in the polyproline helix abrogated more completely Nef-mediated enhancement of viral infectivity; this mutation also adversely affected CD4 downregulation at low levels of Nef expression. Only the R77A mutation substantially impaired downregulation of class I MHC. However, mutation of the central prolines and of R77 yielded proteins that were expressed less efficiently than wild-type Nef. The R77A mutant was expressed most poorly, compatible with its defective phenotypes in all assays. Mutations of the hydrophobic pocket were minimally detrimental to both the virologic and the receptor modulatory functions of Nef. Taken together, this analysis suggests that mutations in the SH3-binding domain do not abrogate fully any Nef-associated phenotype in the absence of detrimental effects on protein expression. We suggest that mutations in this domain can introduce incomplete effects caused by subtle impairments to protein expression; these effects may appear selective under certain experimental conditions due to different sensitivities of the assays to the level of Nef expression.
Breast cancer tumor size: correlation between magnetic resonance imaging and pathology measurements

Abstract Background As physicians increasingly use magnetic resonance imaging (MRI) for the evaluation of newly diagnosed breast cancers, a review of the correlation between MRI and pathology tumor size is imperative. Methods A retrospective review of 91 breast tumors comparing preoperative MRI tumor size to final pathology tumor size was performed. Results MRI and pathology tumor size were positively correlated (R = .650), but with an average overestimation by MRI of .63 cm (P 2.0 cm), a significant difference was found only in tumors greater than 2.0 cm (average overestimation = 1.06 cm; P Conclusions MRI tumor size correlates with pathology size; however, a significant overestimation exists, particularly for tumors >2.0 cm. Clinicians should therefore use caution in relying on MRI tumor size in determining candidacy for breast conservation therapy (BCT).
Reliability of special tests in measuring personality.

This study investigated the reliabilities, cross validations, and patterning of the external validities of five inventories using opposite-form approach. 181 college Ss were tested four times, and their course grades calculated. Various correlations were compared. Results showed that these opposite-form inventories were comparable in internal-consistency reliabilities, in the cross validation of test-retest reliabilities and opposite-form reliabilities, and in the correlation with course grades.
Three-dimensional structure of human cytomegalovirus protease.

HERPESVIRUSES encode a serine protease1,2that specifically cleaves assembly protein3. This protease is critical for replication4, and represents a new target for antiviral drug design5. Here we report the three-dimensional structure of the protease from human cytomegalovirus (hCMV) at 2.27 A resolution. The structure reveals a unique fold and new catalytic strategy for cleavage. The monomer fold of the enzyme, a seven-stranded β-barrel encircled by a chain of helices that form the carboxy terminus of the molecule, is unrelated to those observed in classic serine proteases such as chymotrypsin and subtilisin. The serine nucleo-phile at position 132 is activated by two juxtaposed histidine residues at positions 63 and 157. Dimerization, which seems to be necessary for activity6,7, is observed in the crystals. Correlations of the structure with the sequences of herpesvirus proteases1,5,8 suggest that dimerization may confer specificity and recognition in substrate binding.
Equilibrium Binding in Immunosensors

An in vitro solid-phase immunoassay system was studied in order to characterize immunosensor binding reactions. Several variables were explored, including the spacing of immobilized antibodies and the size and valence of analyte analogs. Under appropriate conditions, binding enhancement was observed, suggesting that the chemistry of the system can be experimentally controlled in order to meet specified criteria for sensitivity and other characteristics of the biosensor.
Web-based telemicroscopy.

By taking advantage of network-based computing and the recent developments in Web interfaces, centralized research facilities housing specialized and unique imaging instruments along with associated high-performance computing can be made available to researchers for use from their own laboratories. In addition to increasing access and utilization of these facilities, operation over the Internet is expected to enhance research by facilitating collaboration between researchers. We describe the implementation of a platform-independent Web-based system written in Java that supplements automated functions with video-guided interactive, collaborative remote control and data acquisition from an intermediate-high-voltage electron microscope.
EFFECTS OF AGE, SEX, AND STATUS ON PERCEPTION OF THE UTILITY OF EDUCATIONAL PARTICIPATION

This study investigated the influence of age, sex, and socioeconomic status on the perception of participants in adult education that their participation is useful. Two forms of utility were postulated: instrumental and expressive. An instrument containing scales of perceived utility, needs, goals, time orientation, and enjoyment was administered to selected classes at various educational institutions in the Chicago metropolitan area and, for comparison, a class in Florida. The results permitted inferences that needs, goals, and time orientation partially determine perception that participation is instrumentally useful and that age, status, and femaleness tend to favor perception of expressive utility. The findings supported previous research indicating that adult educational participation is complex behavior involving more than subject matter interests and motivational orientations and opened a new line of attack on the problem.
Cattle Waste Treatment and Class A Biosolid Production Using Temperature-phased Anaerobic Digester

Abstract The performance of the temperature-phased anaerobic digestion (TPAD) process in the digestion of livestock wastes has never been evaluated, though the process has proven advantages over other high-rate anaerobic digestion processes in the treatment of municipal wastewater sludge. This study investigated the applicability of the TPAD process in the stabilization of dairy cattle manure. For the organic loadings investigated from 1.87 to 5.82 g VS/l/day, volatile solids (VS) reduction in the range 36–41% was achieved with biological conversion efficiency of 0.52–0.62 l methane/g of VS destroyed. Fecal Coliform and Salmonella counts in the residual solids were less than the limits specified by U.S.E.P.A. to meet Class A Standards. The high volatile fatty acid concentrations in the thermophilic effluent were reduced significantly by the mesophilic stage and ammonia nitrogen concentrations in the reactors were below inhibitory levels. The process was stable at all the organic loading rates studied.
The Differential Range Spectrum of Cosmic-Ray Mesons at Sea Level

The low energy region of the differential range spectrum of cosmic-ray mesons at sea level has been investigated by means of a counter controlled cloud chamber. The results obtained in the region from 18 g/${\mathrm{cm}}^{2}$ to 76 g/${\mathrm{cm}}^{2}$ of air equivalent absorber have proved to be about 20 percent higher than predictions based upon similar measurements at greater absorber thicknesses. A possible explanation of this discrepancy lies in the consideration of the effect of multiple scattering of mesons in previous experiments. The present experiment employs a geometrical arrangement of the apparatus which minimizes the corrections to be applied to the data to allow for loss of mesons from the apparatus due to scattering. The earlier work in the field has not been corrected for scattering effects and can, as a result, be expected to give too low a value of the spectrum. The average differential intensity of mesons measured in the range interval mentioned above is 6.86\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}6}$ (particles/sec/sterad/g). The differential range spectrum of protons was also measured and is in good agreement with other work which measured the spectral values at somewhat higher energies than those encountered here. The proton intensity is 2.12\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}6}$ (particles/sec/sterad/g) in the region 16.5 to 42.3 g/${\mathrm{cm}}^{2}$ of air equivalent and 0.67\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}6}$ (particles/sec/sterad/g) in the region 42.5 to 63.3 g/${\mathrm{cm}}^{2}$ of air equivalent.
Isolation and identification of α-(4-pyridyl-1-oxide)-N-tert-butylnitrone radical adducts formed by the decomposition of the hydroperoxides of linoleic acid, linolenic acid, and arachidonic acid by soybean lipoxygenase

Abstract α-(4-Pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN) radical adducts, which are formed in the reactions of soybean lipoxygenase with linoleic acid, arachidonic acid, and linolenic acid, were isolated using HPLC-ESR spectroscopy. Both linoleic acid and arachidonic acid gave one radical adduct, whereas in the case of linolenic acid, two radical adducts were isolated. These radical adducts all showed virtually identical uv spectra with λmax at 292 and 220 nm in hexane. The absence of absorbance with λmax at 234 nm indicates that a conjugated diene structure is not contained in these radical adducts. The mass spectra of the radical adducts formed from linoleic and arachidonic acids were identical and contained a molecular ion of m z 264, consistent with the trapping of the pentyl radical by 4-POBN. Indeed, authentic 4POBN pentyl radical adduct obtained from the reaction between pentylhydrazine and 4-POBN gave the same mass spectrum as the product obtained from the reaction of linoleic acid and arachidonic acid with 4-POBN. The two 4-POBN radical adducts formed in the linolenic acid reaction were shown by mass spectrometry to be isomers of pentenyl radicals. The 4-POBN-pentyl radical adduct was also detected in the reaction mixture of 13-hydroperoxy-linoleic acid, soybean lipoxygenase, and 4-POBN, indicating that the pentyl radical and pentenyl radical are formed by the decomposition of the hydroperoxides.
Photoendocrine transduction in cultured chick pineal cells. III. Ouabain (or dark) pulses can block, overcome, or alter the phase response of the melatonin rhythm to light pulses

A photoentrainment pathway, circadian pacemakers, and the apparatus for regulated melatonin production all reside within chick pineal cells. Pulses of white light (L), or darkness (D), or ouabain (Ob), in otherwise constant red light, induce phase-dependent phase shifts in the rhythm of melatonin output displayed by these cells in static culture. The phase response curves (PRCs) (which describe the relationship between the phase at which a pulse is given and the resulting phase shift) for Ob and for D are quite similar, and differ from the PRC for L pulses. Here, we describe the effects of pulses of Ob, L, and D, in combination, on subsequent phase of the melatonin rhythm. Ob pulses can block, overcome, or alter the phase response to light pulses, depending on the phases and concentrations used. Under appropriate conditions, D pulses can, like Ob, convert the phase response to a light pulse from phase delays to phase advances. Such alterations in the response to a second pulse (L) caused by a first pulse (Ob or D) implies a rapid resetting of the phase of the underlying pacemaker. The interactions of Ob, L, and D are consistent with, but do not require, the convergence of their entrainment pathways on the same oscillating component of the pacemaker.
Neoliberal Europe: Enabling Ethno-Cultural Neutrality or Fueling Neo-Nationalist Sentiment?

Ideologically committed to the neoclassical notion of "market discipline," the neoliberal regime is argued to promote principles of ethno-cultural neutrality and to create a level-playing field for all individuals regardless of race, class, gender, or other marker of minority status. However, in practice, neoliberal policies have increased the incidence of economic marginalization among lower and middle socio-economic classes in Europe, and have contributed to growing tensions between cultural majorities and ethnic minority groups. While similar sentiments associated with the rise of nationalism in nineteenth century Europe clearly predate the neoliberal era, in this paper I argue that neoliberal policies, backed by European Union institutions, have created material conditions which have exposed and widened structural incompatibilities between the notions of state and nation. Since the 1990s, these incompatibilities have legitimized the resurgence of radical nationalist sentiment within European nation-st...
Applying the science to the prevention of catheter-related infections.

Abstract Background: Catheter-related bloodstream infection (CR-BSI) remains a leading cause of nososcomial infection, despite the fact that many CR-BSIs are preventable. Simple principles of infection control and the use of novel devices to reduce these infections are not uniformly implemented. Objective: To review and summarize the evidence that promotes strategies to prevent CR-BSIs. Data sources: The Medline database and bibliographies of review articles and book chapters were searched for relevant articles. Studies included: In vitro and in vivo laboratory-based studies, controlled clinical trials, prospective interventional trials, and epidemiologic investigations. Outcome measures: Reduction in CR-BSI, catheter colonization, tunnel infection, or local site infection. Synthesis: The recommended prevention strategies with strong supportive evidence include educating and training of health care providers who insert and maintain catheters; using full barrier precautions during central venous catheter insertion; using a 2% chlorhexidine preparation for skin antisepsis; eliminating the practice of scheduled replacement of central venous catheters for prevention of infection; and using antiseptic/antibiotic impregnated short-term central venous catheters. Conclusion: Simple interventions can reduce the risk for serious catheter-related infection. Health care provider awareness and adherence to these prevention strategies is critical to reducing the risk for CR-BSI, improving patient safety, and promoting quality health care. Copyright 2002, Elsevier Science (USA). All rights reserved.
Ophthalmological sequelae following post-haemorrhagic hydrocephalus

In the IVH group, ophthalmic problems were seen in 21 children (80.8%). Strabismus was seen in 17 children (65.4%), optic atrophy in ten children (38.5%), refractive errors in ten children (38.5%), severe visual impairment in seven children (26.9%), retinopathy of prematurity (ROP) in nine eyes of five children (19.2%), optic nerve hypoplasia (ONH) in four children (15.4%) and nystagmus in four children (15.4%).In the non-IVH group ophthalmic problems were encountered in 19 patients (86.4%). Strabismus was seen in 15 children (68.2%), optic atrophy in only one child (4.5%), refractive errors in 12 children (54.5%), severe visual impairment in five children (22.7%), nystagmus in two children (9.1%) and ONH in four children (18.2%).This study demonstrates that in spite of similar overall prevalence of ophthalmological complications in the two groups (p = 0.71, Fisher exact, 2-tailed value), there is a significantly higher incidence of optic atrophy in the IVH group (p = 0.01, Yates corrected Chi-square test...
Atrioventricular valve regurgitation in patients with single ventricle: impact of the bidirectional cavopulmonary anastomosis

Abstract Background. It is not known whether atrioventricular valve regurgitation (AVVR) can improve in some patients after the bidirectional cavopulmonary anastomosis (BCPA) without undertaking concomitant valvuloplasty. Methods . We retrospectively reviewed our experience with patients who underwent the BCPA between June 1989 and June 2000 with specific attention to those patients with moderate or severe AVVR. The degree of AVVR was determined by color Doppler echocardiography. During the study period there were 576 patients who underwent BCPA at a median age of 6.8 months (range, 1.3 months to 4.8 years). The majority of subjects (66%) had a tricuspid valve as the systemic atrioventricular valve. Significant (moderate or severe) AVVR before BCPA was noted in 36 of 576 patients (6%) and was significantly more prevalent (8 of 52 patients, 15%; p = 0.01) in patients with a common atrioventricular canal. Results . Of the 36 subjects with moderate or severe AVVR, 8 had interventions (6 valvuloplasty, 2 aortic arch dilation) at BCPA. There was 1 hospital death (2.8%). Of the remaining 27 survivors who did not undergo additional interventions at BCPA, improvement in AVVR (mild or none) was noted in 6 (22%) at intermediate follow-up (median, 2 years; range, 0.5 to 3.1 years). The presence of significant AVVR before BCPA was not significantly associated with hospital survival or intermediate-term freedom from death or transplantation. Conclusions . We conclude that AVVR improves in some patients after BCPA and that valvuloplasty is not justified in all patients with moderate preoperative AVVR.
Flash photolysis of flavins. V. Oxidation and disproportionation of flavin radicals.

Flash photolysis techniques have been utilized to investigate the reactivity patterns of flavin radical species. Rate constants for disproportionation were found to be la the following order: lumiflavin>FMN>FAD and neutral radicals>anionic radicals. Neutral flavin radicals react with oxygen at a rate which is at least 104 times slower than the anionic species. No evidence for an intermediate complex or adduct is obtained in this reaction. The pK values for the ionization of the neutral flavin radicals are in the order FAD>FMN>riboflavin=limiflavin. The rates of reaction of ferricyanide with flavin radicals are essentially independent of pH, whereas benzoquinone reacts slightly more slowly (≅5 times) with the neutral flavin radical than with the anionic form. Cytochromec reacts at least ten times more slowly with flavin radicals than does ferricyanide.
PARTICLE PRODUCTION, CHEMICAL EQUILIBRIUM, AND THE QUASIERGODIC HYPOTHESIS IN HIGH-ENERGY COLLISIONS

Starting from kinetic theory, it is shown that particles heavier than the pion are not produced in chemical equilibrium. A new theory based on the degree of the reaction is then formulated. Pion induced reactions, following pion production from individual nucleon-nucleon collisions give the main mechanism for the production of strange particles, such as K/sup +/'s. ''Subthreshold'' production is a natural consequence of the theory.
Acid rain and drinking water degradation

Acid deposition-induced drinking water degradation is discussed with respect to the geographical extent of and the potential for dealing with possibly adverse human health impacts. Qualitative evidence from the northeastern United States and Sweden strongly suggests the existence of a linkage between these two environmental concerns. It is argued that water treatment and reduction of acid rain as solutions to the problem of water toxicity need closer evaluation. More research into the causal link is warranted since the addition of human health impacts to acid rain's environmental insults could have a significant bearing on discussions relating to acid rain controls.
Primary Care Providers' Judgments of Opioid Analgesic Misuse in a Community-Based Cohort of HIV-Infected Indigent Adults

BACKGROUND Primary care providers (PCPs) must balance treatment of chronic non-cancer pain with opioid analgesics with concerns about opioid misuse.
Phase Separated Microstructure and its Stability in InGaAs Epitaxial Layers Grown by LPE

In 0.53 Ga 0.47 As layers were grown by LPE on (001) InP substrates in the temperature range of 480~780°C. The fine speckle contrast, which is attributed to two-dimensional phase separation, was observed in layers grown at temperatures as high as 780°C. Since the critical temperature for bulk miscibility gap is predicted to be around 450°C, this suggests that in the presence of the surface the critical temperature for the two-dimensional surface decomposition is higher than that for the bulk. The wavelength of the fine modulations does not change with the growth temperature. This could be due to the fast diffusion kinetics in the solid-liquid interface and the balance between the driving force and the gradient energy. To examine the stability of the above microstructures, zinc diffusion experiments were carried out in the temperature range of 390 to 540°C using the ampoule technique. The diffused layers exhibit homogenous microstructures. This demonstrates that critical temperature for phase separation in bulk is below 390°C and is comparable to that predicted by theory.
Quantitative Response to Daylength during Diapause in Insects

WITH few exceptions investigations into photoperiodically controlled seasonal activity in insects have used stationary light-dark cycles; no experiments known to us have defined the role of increasing or decreasing daylengths in nature. We therefore investigated the influence of natural daylengths on diapause duration and termination, using the green lacewing, Chrysopa carnea Stephens (Neuroptera). This species undergoes a reproductive diapause when subjected to short day-lengths below a critical photoperiod1. A large decrease in stationary daylength above the critical photoperiod can also induce diapause; an increase in stationary daylength below the critical photoperiod can either avert or terminate diapause2. It was not clear from these laboratory experiments, however, if C. carnea can perceive natural changes in daylength, so we tested (a) whether the naturally decreasing daylengths in autumn have a role in maintaining diapause and (b) whether increasing daylengths after the winter solstice hasten the end of diapause.
NEURAL MECHANISMS OF AUDITORY DISCRIMINATION OF LONG-DURATION TONAL PATTERNS: A NEURAL MODELING AND FMRI STUDY

Language perception comprises mechanisms of perception and discrimination of auditory stimuli. An important component of auditory perception and discrimination concerns auditory objects. Many interesting auditory objects in our environment are of relatively long duration; however, the temporal window of integration of auditory cortex neurons processing these objects is very limited. Thus, it is necessary to make active use of short-term memory in order to construct and temporarily store long-duration objects. We sought to understand the mechanisms by which the brain manipulates long-duration tonal patterns, temporarily stores the segments of those patterns, and integrates them into an auditory object. We extended a previously constructed model of auditory recognition of short-duration tonal patterns by expanding the prefrontal cortically-based short-term memory module of the previous model into a memory buffer with multiple short-term memory submodules and by adding a gating module. The gating module distributes the segments of the input pattern to separate locations of the extended prefrontal cortex in an orderly fashion, allowing a subsequent comparison of the stored segments against the segments of a second pattern. In addition to simulating behavioral data and electrical activity of neurons, our model also produces simulations of the blood oxygen level dependent (BOLD) signal as obtained in fMRI studies. The results of these simulations provided us with predictions that we tested in an fMRI experiment with normal volunteers. This fMRI experiment used the same task and similar stimuli to that of the model. We compared simulated data with experimental values. We found that two brain areas, the right precentral gyrus and the left medial frontal gyrus, correlated well with our simulations of the memory gating module. Other fMRI studies of auditory perception and discrimination have also found correlation of fMRI activation of those areas with similar tasks and thus provide further support to our findings.
Defective thymocyte proliferation and IL-2 production in transgenic mice expressing a dominant-negative form of CREB

The basic/leucine zipper (bZip) transcription factor, CREB, binds to the CRE element (TGANNTCA). The transcriptional activity of CREB requires phosphorylation of the protein on a serine residue at position 119 (ref. 6). CREs are present in a number of T-cell genes but the precise role of CREB in T-cell differentiation and function was unknown. Here we show that resting thymocytes contain predominantly unphosphorylated (inactive) CREB, which is rapidly activated by phosphorylation on Ser 119 following thymocyte activation. T-cell development is normal in transgenic mice that express a dominant-negative form of CREB (CREBA119, with alanine at position 119) under the control of the T-cell-specific CD2 promoter/enhancer. In contrast, thymocytes and T cells from these animals display a profound proliferative defect characterized by markedly decreased interleukin-2 production, G1 cell-cycle arrest and subsequent apoptotic death in response to a number of different activation signals. This proliferative defect is associated with the markedly reduced induction of c-jun, c-fos, Fra-2 and FosB following activation of the CREBA119 transgenic thymocytes. We propose that T-cell activation leads to the phosphorylation and activation of CREB, which in turn is required for normal induction of the transcription factor AP1 and subsequent interleukin-2 production and cell-cycle progression.
Quality evaluation and concentrate supplementation of rotational pasture grazed by lactating cows.

Abstract The effects of pasture quality and the amount and nutrient composition of a concentrate supplement on performance of lactating cows were investigated under a controlled rotational grazing system. Pasture samples were collected for two consecutive summers, and the relationship was positive between wet chemistry and near infrared reflectance spectroscopy for CP, ADF, and NDF. During yr 2, 54 Holstein cows averaging 82 d postpartum were used in a randomized block design to evaluate three methods of supplementing grain for a 24-wk trial. A 16.2-ha area of primarily orchardgrass pasture was divided into paddocks of approximately .40 ha each. The three supplemental grain rations were 1) 1 kg of grain/3 kg of milk; 2) 1 kg of grain/4 to 5 kg of milk adjusted weekly, depending upon the quantity of pasture available; and 3) 1 kg of grain/4 to 5 kg of milk. The amount fed in ration 3 was adjusted weekly, depending upon the quantity of pasture available, and reformulated biweekly based on analysis of pasture. No differences existed among treatments for milk production (24.7, 23.2, and 24.1 kg/d) or 3.5% FCM (25.3, 24.8, and 24.9 kg/d) over the 24-wk trial. Cows fed more grain (ration 1) gained more BW. Adjusting nutrient density of the grain to changes in pasture quality resulted in similar milk production and a lower ration cost.
Convergence of O ( h 4 ) cubic spline collocation methods for elliptic partial differential equations

This paper presents a new class of collocation methods using cubic splines for solving elliptic partial differential equations (PDEs). The error bounds obtained for these methods are optimal. The methods are formulated and a convergence analysis is carried out for a broad class of elliptic PDEs. Experimental results confirm the optimal convergence and indicate that these methods are computationally more efficient than methods based on either collocation with Hermite cubics or on the Galerkin method with cubic splines. Various direct and iterative methods have been applied for the solution of cubic spline collocation methods.
An Efficient Medium for High Protein Production in the Insect Cell/Baculovirus Expression System

Previously, we have described a serum-free insect cell culture medium, referred to as Efficient Medium for Insect Cell Growth (EMICG) (Ferrance et al., 1993) . The medium supports cell growth to a high density and minimizes the formation of metabolic byproducts (e.g., ammonia and alanine) due to a tight coupling of energetic and biosynthetic demands. In this paper, we examine the ability of EMICG to support infection and recombinant protein production. Cells were infected with and without medium replacement at various densities with MOI values in the range 0.008–8. The experimental results revealed that the production of β-galactosidase (model recombinant protein) was substantially higher (1.5–2.6-fold) in the EMICG cultures than the commercial SF-900 II medium. Moreover, β-galactosidase levels achieved in EMICG are higher than those reported in the literature using other commercial media. Results of experiments in which medium was replaced at the time of infection indicate that the enhanced productivity may be due to lower production of toxic by-products in EMICG.
Technical note: Dosimetry in the moving gap region in craniospinal irradiation

To minimize the risk of overlap of adjoining orthogonal fields in craniospinal irradiation, a skin gap is usually maintained between the caudal margin of the brain fields and the cephalic margin of the spine field. The moving gap technique (feathering) is commonly used to improve the dose in the gap region. Using Kodak XV ready-pack films and a polystyrene phantom, the dosimetry in the moving gap region at the depth of spinal cord for different gap sizes and feathering step sizes was studied. The dose profiles in the moving gap region with half-beam block set-up were also measured. Our results show that the combination of a small skin gap and a larger feathering step size results in a higher dose in the moving gap compared with that with identical gap and feathering step sizes. For example, with a 0.5 cm gap and 1 cm feathering step size, the dose in the moving gap region at depth of 5 cm ranges from 82 to 88% of the dose to the brain field. The corresponding dose range with 1 cm gap and 1 cm feathering step size is about 68-73%. With no gap and 1 cm feathering step, a dose range of 92-98% is achieved in the moving gap. The slightly steeper penumbra of a half-beam block used in the brain fields does not result in any dosimetric advantage in the moving gap compared with the conventional set-up when feathering is employed. The use of abutting orthogonal fields in craniospinal irradiation creates a dosimetric problem in the junction between the brain and the spine fields, namely overdosage to the spinal cord due to junction overlap. To minimize the risk of overlap due to beam divergence, set-up error or patient movement, a skin gap is usually maintained between the caudal margin of the brain field and the cephalic margin of the spine field. The lower dose received in the gap region is accepted as a compromise to ensure that the tolerance of the spinal cord is not exceeded. Several methods have been used to improve the dosimetry in the gap region [1-4]. The most commonly used method is perhaps the moving gap technique or feathering in which the gap between the brain fields and the spine field is shifted in each treatment by a known distance along the spinal column to reduce the risk of overdosage of the spinal cord and to improve the dose in the junction. The shift of the skin gap is accomplished by changing (increasing, decreasing) the length of the brain fields and that of the spine field by the same amount to effectively move the gap in the caudal (cephalic) direction. In addition, the collimator and couch angles are adjusted according to the beam diver
Intravenous isoproterenol: Rationale for bronchial asthma

Abstract Intravenous isoproterenol was infused into 7 adult asthmatic patients with refractory bronchial obstruction. Over a dose range of 0.0375 to 0.225 μg per kilogram per minute, maximal bronchodilator effect (or reversal of effect) occurred within 2 to 5 minutes of starting (or stopping) the infusion. Obstruction to airflow improved with each increment of dose. Average heart rate reached a maximum at 0.075 μg per kilogram per minute. Over the lower dose range alveolar to arterial oxygen gradients widened and heart rate increased; over the higher dose range, as heart rate plateaued, bronchodilator effect continued and oxygen gradient narrowed. When combined with adequate oxygenation and continual monitoring of cardiac rhythm and blood pressure, intravenous isoproterenol appears safe for asthmatic patients. Major advantages are (1) administration of bronchodilator to airways not reached by inhalation, (2) prompt onset and offset of effects, and (3) reversal of undesirable side effects. The use of intravenous isoproterenol may obviate the need for intubation and ventilatory assist.
The effect of powder particle fusion on the mechanical properties of ultra-high molecular weight polyethylene

Rheo-optical and mechanical property studies with compression molded ultra-high molecular weight polyethylene specimens at different temperatures indicate that their mechanical performance is dependent on the degree of fusion of the powder particles during compression and can be enhanced by heating the polymer powder at temperatures above 220°C. Although the mechanical performance of the compression molded specimens can be improved further by solid-state drawing at a draw ratio 5, the anisotropic morphologies from molded specimen above 220°C have higher initial slope of stress to elongation, strength to break, and an outstanding elastic recovery in compreision to the compression molded specimens at 180°C.
Copolymerization of some epoxides by coordination‐type catalysts

Copolymerizations of tritiated phenyl glycidyl ether with p- and m-methoxy, p-methyl, and p-chloro analogs, as well as with propylene oxide and epichlorohydrin are reported. The relative reactivities indicate greater Lewis acid character for triethylaluminum–water than for diethyl-zinc–water or ferric chloride–propylene oxide catalyst systems. The copolymerization of the PGE analogs is promoted by electron-donor groups and retarded by electron-withdrawing groups.
Spin limits of Solar System bodies: From the small fast-rotators to 2003 EL61

Abstract Holsapple [Holsapple, K.A., 2001. Icarus 154, 432–448; Holsapple, K.A., 2004. Icarus 172, 272–303] determined the spin limits of bodies using a model for solid bodies without tensile or cohesive strength, but with the pressure-induced shear strengths characteristic of dry sands and gravels. That theory included the classical analyses for fluid bodies given by Maclaurin, Jacobi and others as a special case. For the general solid bodies, it was shown that there exists a very wide range of permissible shapes and spin limits; and explicit algebraic results for those limits were given. This paper gives an extension of those analyses to include geological-like materials that also have tensile and cohesive strength. Those strengths are necessary to explain the smaller, fast-rotating asteroids discovered in the last few years. I find that the spin limits for these more general solids have two limiting regimes: a strength regime for bodies with a diameter 10 km (which is the case covered by the earlier papers). I derive explicit algebraic forms for the dependence of the spin limits on shape, mass density and material strength properties. The comparison of the theory to the database for the spins of asteroids and trans-neptunian objects (TNO's) objects shows excellent agreement. For large bodies (diameter D > 10 km ), the presence of cohesive and/or tensile strength does not permit higher spin rates than would be allowed for rubble pile bodies. Thus, the fact that the spin rates of all large bodies is limited to periods greater than about 2 h does not imply that they are rubble piles. In contrast, for small bodies ( D 10 km ) the presence of even a very small amount of strength allows much more rapid spins. Small bodies might then be rubble piles but require a small amount of bonding. Finally, I make some remarks about the application of the theory to the TNO's and large asteroids, and question whether a common assumption by researchers that those bodies must take on relaxed fluid shapes is warranted. If not, then the densities and shapes required by that assumption are not valid. I use 2003 EL61 as a prime example.
Dynamic global games of regime change: Learning, multiplicity, and the timing of attacks

Global games of regime change-coordination games of incomplete information in which a status quo is abandoned once a sufficiently large fraction of agents attack it-have been used to study crises phenomena such as currency attacks, bank runs, debt crises, and political change. We extend the static benchmark examined in the literature by allowing agents to take actions in many periods and to learn about the underlying fundamentals over time. We first provide a simple recursive algorithm for the characterization of monotone equilibria. We then show how the interaction of the knowledge that the regime survived past attacks with the arrival of information over time, or with changes in fundamentals, leads to interesting equilibrium properties. First, multiplicity may obtain under the same conditions on exogenous information that guarantee uniqueness in the static benchmark. Second, fundamentals may predict the eventual fate of the regime but not the timing or the number of attacks. Finally, equilibrium dynamics can alternate between phases of tranquility-where no attack is possible-and phases of distress-where a large attack can occur-even without changes in fundamentals.
Acetonitrile—diatomaceous earth column for separation of steroids and other compounds

The retention characteristics of 53 compounds on an acetonitrile-diatomaceous earth column are given for elution with n-heptane followed by stripping with chloroform. Nineteen of the compounds were eluted completely, seven were eluted partially, and 27 (including the 12 corticosteroids tested) were not eluted at all by 150 ml. of n-heptane. Partially eluted compounds could be completely eluted by larger volumes of n-heptane. Elution characteristics in a group of similar compounds are affected greatly by relatively minor changes in structure. The recommended procedure furnishes a simple and rapid method for the separation of mixtures and for the detection of impurities or decomposition in standards. Several pharmaceutical preparations and known mixtures were analyzed as examples of the application of the column procedure to various products.
Numerical Investigation of Microscale Slot Jet Impingement Using DSMC-IP and CFD

The standard Direct Simulation Monte Carlo (DSMC) simulation is not capable of producing statistically meaningful results for low Re flows which are often encountered in microflows. Therefore, the non-isothermal Information Preservation (IP) algorithm is utilized in this study to predict the flow structure and the heat transfer characteristics of a microscale, slot, and confined jet impinging on a flat surface with uniform temperature boundary condition. The flow Knudsen number based on the slot width is in the slip flow and the lower transition regime. The jet is impinging at jet-to-target surface gaps normalized by slot width (H/W) of 0.25, 1 and 2 at a pressure ratio of 2.0. The effects of impingement gap (H/W) on flow structure and heat transfer are investigated. The velocity, pressure and Nusselt number distributions on the impingement target surface are presented. The results are compared to corresponding conventional large-scale values.Copyright © 2007 by ASME
Improving bandwidth for line-of-sight optical wireless in turbulent air by using phase conjugation

An optical link over several kilometers between buildings or remote sites will have significantly reduced bandwidth in the presence of turbulent air, such as may be caused by convection from a heated earth surface. Bandwidth is decreased by amplitude and phase fluctuations due to the turbulence. This paper investigates the performance improvement in bandwidth by using a phase conjugate reflected beam for signal transmission. Weak fluctuations, consistent with the Rytov transformation, are assumed. A computer simulation is developed that uses a statistical model of the turbulent channel to assess the effectiveness of this approach.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.