cssi/SciSciGPT-SciSciNet huggingface dataset:
Antagonistic relationships between intron content and codon usage bias of genes in three mosquito species: functional and evolutionary implications

Genome biology of mosquitoes holds potential in developing knowledge-based control strategies against vectorborne diseases such as malaria, dengue, West Nile, and others. Although the genomes of three major vector mosquitoes have been sequenced, attempts to elucidate the relationship between intron and codon usage bias across species in phylogenetic contexts are limited. In this study, we investigated the relationship between intron content and codon bias of orthologous genes among three vector mosquito species. We found an antagonistic relationship between codon usage bias and the intron number of genes in each mosquito species. The pattern is further evident among the intronless and the intron-containing orthologous genes associated with either low or high codon bias among the three species. Furthermore, the covariance between codon bias and intron number has a directional component associated with the species phylogeny when compared with other nonmosquito insects. By applying a maximum likelihood–based continuous regression method, we show that codon bias and intron content of genes vary among the insects in a phylogeny-dependent manner, but with no evidence of adaptive radiation or species-specific adaptation. We discuss the functional and evolutionary significance of antagonistic relationships between intron content and codon bias.
Modeling of task-dependent characteristics of human operator dynamics pursuit manual tracking

To model human operator (HO) dynamics in manual tracking tasks, an ensemble of models, each for a certain class of inputs, seems to be needed. By placing in a linear framework the modeling studies so far conducted, it is evident that different hypotheses have been proposed to explain the observed input dependence of the estimated HO (linear) models. Here, the authors examine these hypotheses and propose that the systemic notion of task dependence must be used to model this system. They have explored ways of deriving quantitative measures of the system task-dependent characteristics, using autoregressive moving-average (ARMA) models of input-output data obtained from a series of pursuit manual tracking experiments. These experiments utilized sum-of-sinusoids and random ternary inputs of various bandwidths. The resulting model parameters indicate significant task dependence of the HO dynamic characteristics. The effect of amplitude nonlinearities was examined and found to be statistically insignificant. >
Policy Monitor—Bonding Requirements for U.S. Natural Gas Producers

AbstractNatural gas producers are constantly making tradeoffs between money, time, and environmental risk. The private costs and benefits of drilling are realized immediately, but the external cost...
PARTIAL LIFE-CYCLE ANALYSIS: A MODEL FOR BIRTH-PULSE POPULATIONS

Matrix population models have become standard tools for the demographic analysis of age- or stage-structured populations. Although age-classified (Leslie) matrix models make maximum use of age-specific demographic data, age at first reproduction, which has been suggested to be an important life-history variable, does not appear as an explicit parameter in these models. Consequently, the sensitivity of population growth rate to changes in age at first reproduction cannot be calculated using standard techniques. Age-specific demographic data to parameterize age-structured models are difficult to collect, and models that can be parameterized with partial demographic data (“partial life-cycle models”) have been developed. Partial life-cycle models are based on life-history stages, and these models can also be used to calculate sensitivity of population growth rate to changes in various life-history variables, including ages at first and last reproduction. Here, we present a partial life-cycle model appropriate for situations where demographic data are collected immediately after the birth pulse (post-breeding census). We present methods of parameterizing the partial life-cycle model, and derive formulas for calculating the sensitivity of the population growth rate to changes in model parameters, including ages at first and last reproduction. We analyzed life-table data for several species of mammals using the partial life-cycle model and found that results of our partial life-cycle model compare favorably with those obtained from the corresponding age-classified models.
International Perspective: Training Needs in Saudi Arabia—A Survey of Managers

Abstract This study examined to what extent the commerce/management education provided by Saudi universities is aligned with the needs of the Saudi private sector. Specifically, the study first identified the level of importance attached to a set of training/skill areas by the executives of Saudi private sector companies, and then sought their opinions concerning how well the present educational system satisfies those needs. Results highlight skill/training areas in which matches and mismatches exist. Implications of the results are discussed.
The effect of brain tumor angiogenesis on the in vivo relationship between the gradient-echo relaxation rate change (DeltaR2*) and contrast agent (MION) dose.

Purpose To determine in vivo if the susceptibility calibration factor for gradient-echo imaging (kG), which characterizes the relationship between the tissue T2* relaxation rate change (ΔR2*) and tissue contrast agent concentration, is independent of tissue type and condition; in addition, to assess the consequences of such an assumption on the use of relative cerebral blood volume (rCBV) measurements as a direct index of tumor angiogenesis. Materials and Methods The ΔR2* was measured as a function of monocrystalline iron oxide nanoparticles (MION) contrast agent dose in a rat brain tumor (9L gliosarcoma) model, the blood volume fraction independently measured, and kG calculated and compared for the normal gray matter, normal white matter, tumor, and contralateral brain. Results The kG was found to be the same for gray and white matter (P = 0.53), but statistically different for tumor compared to contralateral brain (P = 0.005) with k < k Conclusion The gradient-echo calibration factor, kG, is the same for brain gray and white matter, but not the same for brain and tumor tissue. This difference may be attributed to the grossly different vascular morphology of tumors, dueto tumor angiogenesis, compared to normal brain and/or possibly differing blood rheological factors such as hematocrit. Consequently, the sensitivity to blood volume differ-ences between tumor and normal brain tissue may be lessened when using gradient-echo susceptibility contrast agent methods. J. Magn. Reson. Imaging 2003;18:397–403. © 2003 Wiley-Liss, Inc.
Farm Structure and Chemical Use in the Corn Belt1

Why do certain full-time farming operations embrace low-chemical input production practices and not others? Historical records of production from 25 randomly-sampled participants reflecting the conventional approach to production were systematically compared with 14 purposively-chosen low-input farming operations in three Iowa counties. Empirical indicators revealed a consistent relationship between increasing scale and chemical use intensity. In addition, younger family farm operators were more likely to adopt low-input practices. The causal mechanisms that account for these differences in chemical use are presented and related to long-standing debates regarding farm structure and class differentiation in capitalist agriculture.
A Miniature Glow Discharge for Laser Excited Atomic Fluorescence Detection of Lead

Abstract A miniature glow discharge atom reservoir has been designed for laser excited atomic fluorescence spectrometric measurements of nanoliter-sized solution residues. A copper vapor laser pumped dye laser was used to measure the fluorescence of Ph atoms sputtered from the Ni cathode of the discharge. Excitation of Pb occurred at 283.3 nm, and fluorescence was monitored at 405.8 nm. The optimal discharge operating pressure and current were 5.5 Torr and 20 mA with continuous fill gas introduction. No improvement was found in S/N with stop flow versus flowing operation; however, considerable improvement in the S/N was achieved when gated peak integration, in contrast to peak detection, was employed. The temporal profiles indicated that the Pb atoms were rapidly sputtered from the surface of the cathode and that a high percentage of these atoms diffused back toward the cathode. The redeposition of the Pb atoms led to peak tailing with signals lasting more than 60 s. In effect, atoms were sputtered, atomized, and excited several times during a measurement. The limit of detection for Pb was 0.6 pg based on peak detection and 0.03 pg based on peak area measurements. These detection limits were several orders of magnitude higher than the theoretical, intrinsic detection Limit due to the interfering background emission of molecular impurities, such as N 2 and H 2 O, present in the discharge.
Functional Expression of the Colonic H+,K+-ATPase α-Subunit PHARMACOLOGIC PROPERTIES AND ASSEMBLY WITH X+,K+-ATPase β-SUBUNITS

The functional and pharmacological properties of the alpha-subunit of the colonic H+,K+-ATPase (alphaC) were studied in Xenopus laevis oocytes. alphaC was injected with different rat beta-subunits, the beta-subunit of the gastric H+,K+-ATPase (betaG, the only H+, K+-ATPase beta-subunit identified in rat), or the beta1-subunit of the Na+,K+-ATPase (beta1) (associated with the basolateral Na+, K+-ATPase, but also expressed in the epithelial apical membranes of rat distal colon) (Marxer, A., Stieger, B., Quarini, A., Kashgarian, M., and Hauri, H. P. (1989) J. Cell Biol. 109, 1057-1069). The effect of the different beta-subunits was studied by measuring 86Rb+ uptake (a K+ congener) in the presence or absence of Sch-28080 and ouabain. Significant Na+-independent 86Rb+ uptake was observed only when alphaC was coexpressed with one of the beta-subunits. The expressed alphaCbeta1 and alphaCbetaG complexes were not inhibited by Sch-28080, were only partially sensitive to ouabain (IC50 = 400-600 microM, in the presence of external 1 mM KCl), and exhibited comparable K+ activation kinetics. Coexpression of alphaC with epitope-tagged betaG or beta1, followed by immunopurification of the alphabeta complexes, confirmed stable assembly of alphaCbetaG and alphaCbeta1 complexes. Since the beta1-subunit, but not the alpha1-subunit, of Na+,K+-ATPase is expressed in the apical membrane of rat colonocytes, our data support the view that, in rat distal colon, the beta1-subunit may play a surrogate role as the beta-subunit for the colonic H+,K+-ATPase.
Lysozyme as an alternative to antibiotics improves growth performance and small intestinal morphology in nursery pigs

Lysozyme is a 1,4-β-N-acetylmuramidase that has antimicrobial properties. The objective of this experiment was to determine if lysozyme in nursery diets improved growth performance and gastrointestinal health of pigs weaned from the sow at 24 d of age. Two replicates of 96 pigs (192 total; 96 males, 96 females) were weaned from the sow at 24 d of age, blocked by BW and gender, and then assigned to 1 of 24 pens (4 pigs/pen). Each block was randomly assigned 1 of 3 dietary treatments for 28 d: control (two 14-d phases), control + antibiotics (carbadox/copper sulfate), or control + lysozyme (100 mg/kg diet). Pigs were weighed and blood sampled on d 0, 14, and 28 of treatment. Blood was analyzed for plasma urea nitrogen (PUN) and IgA. At 28 d, pigs were killed, and samples of jejunum and ileum were collected and fixed for intestinal morphology measurements. An additional jejunum sample was taken from the 12 pigs with the median BW per treatment to determine transepithelial electrical resistance (TER). Pigs consuming antibiotics or lysozyme grew at a faster rate than control pigs (0.433 ± 0.009 and 0.421 ± 0.008 vs. 0.398 ± 0.008 kg/d, respectively; P 0.48), but G:F was improved in pigs consuming antibiotics or lysozyme (0.756 ± 0.014, 0.750 ± 0.021, and 0.695 ± 0.019 kg/kg; P 0.48). Dietary treatment did not affect TER (P > 0.37), but gilts had lower TER compared with barrows (P 0.53). However, jejunum villi height was increased and crypt depth was decreased in pigs consuming antibiotics or lysozyme (P < 0.001), resulting in an increased villi height:crypt depth of 72% (P < 0.001). Thus, we concluded that lysozyme is a suitable alternative to carbadox/copper sulfate diets fed to pigs weaned from the sow at 24 d of age.
Eating Habits and Dietary Status in Young Children with Autism

While clinical lore appears to accept that young children with autism have limited or narrow diets and unusual food aversions in comparison to same age peers, the empirical basis for this is missing. The goals of this preliminary study were to examine the eating habits and nutritional intake of a young cohort of well characterized children with autism compared to young children with no evidence of autism or other autism spectrum disorders. Parents reported on 19 young children with autism and 15 similar aged children with typical development using a number of informant instruments. Results indicated that children with autism had more mealtime behavioral differences, but these did not translate to significant differences in nutritional status compared to typically developing children. However, there was much variability within both groups. Results are discussed in relationship to what has been previously found in older children with autism spectrum disorders.
On the Stability of Magnetic Baroclinic Flow of an Unbounded Fluid with a Linear Velocity Profile

Abstract The stability analysis of baroclinic magnetic flow for an unbounded fluid with a linear profile is presented. An analytic expression for the stability boundary is found, corroborating the results of Gilman obtained for a confined fluid that there is neither a long wave cutoff for instability nor a maximum value for the magnetic field at which instability may occur. In the limit of vanishing magnetic field the results coincide with those obtained by Burger.
Fundamental approximate identities and quasi-multipliers of simple AF C∗-algebras

Abstract We study C∗-algebras with fundamental approximate identities as a generalization of stable C∗-algebras, and show that the only separable, simple AF C∗-algebras for which the quasi-multipliers equal the left plus right multipliers are unital or elementary.
f-Element/crown ether complexes. 26. Crystallization of two hydrated forms of hydrogen bonded complexes of NdCl3·nH2O and 15-crown-5. Crystal structures of [Nd(OH2)9]Cl3·15-crown-5·H2O and [NdCl2(OH2)6]Cl·15-crown-5

Abstract When slowly evaporated, the reaction of NdCl3· nH2O with 15-crown-5 in a 3:1 mixture of acetonitrile:methanol produces two crystalline hydrates. The decahydrate, [Nd(OH2)9]Cl3·15-crown-5·H2O, is orthorhombic, P212121, with (at −150 °C) a = 10.571(4), b = 15.220(7), c = 15.686(7) A, and Dcalc = 1.71 g cm−3 for Z = 4. These crystals are stable to the moisture in air. Each Nd is nine-coordinate with tricapped trigonal prismatic geometry. The nine coordinated water molecules are hydrogen bonded to two symmetry related crown ethers, all three chloride ions, and the tenth water molecule. The crown has a total of six hydrogen bonds, four on one side (two to a single oxygen atom) and two on the other. This ether exhibits conformational disorder. The hexahydrate, [NdCl2(OH2)6]Cl·15-crown-5 is deliquescent, dissolving in air and recrystallizing as [NdCl2(OH2)6]Cl. Crystals of this complex are monoclinic, P21/n, with (at 20 °C) a = 9.821(3), b = 16.978(9), c = 12.849(8) A, β = 94.06(5)°, and Dcalc = 1.80 g cm−3 for Z = 4. The Nd atom exists in a distorted dodecahedral geometry with one chlorine in an A site and one in a B site. The coordinated chlorine atoms accept hydrogen bonds producing polymeric zigzag hydrogen bonded chains along c. The third noncoordinated chloride ion accepts four hydrogen bonds, three from one formula unit and one from a second formula unit related by a unit translation along a. The crown ethers accept five hydrogen bonds, two on one side, and three on the other, thus separating the zigzag chains along b.
Abstract A35: The role of Mdm2 cleavage in p53 function and chemotherapy response

Chemotherapy resistance is a major obstacle in cancer treatment, yet the mechanisms of resistance to specific therapies have been largely unexplored in vivo. Employing genetic, genomic, and imaging approaches, we have examined the dynamics of response to a mainstay chemotherapeutic, cisplatin, in multiple mouse models of human non-small cell lung cancer (NSCLC). We show that lung tumors initially respond to cisplatin and exhibit a significant reduction in tumor burden. Prolonged cisplatin treatment promotes the emergence of resistant tumors with enhanced repair capacity that are cross-resistant to platinum analogs, exhibit advanced histopathology, and possess an increased frequency of genomic alterations. Cisplatin-resistant tumors express elevated levels of multiple DNA damage repair and cell cycle arrest-related genes, including p53-inducible protein with a death domain (Pidd). We show that PIDD expression promotes growth arrest and chemotherapy resistance by a mechanism that depends on Caspase-2 and wild-type p53. PIDD-induced Caspase-2 directly cleaves the E3 ubiquitin ligase Mdm2 at Asp 367, leading to loss of the C-terminal RING domain responsible for p53 ubiquitination. As a consequence, N-terminally truncated Mdm2 binds p53 and promotes its stability. Upon DNA damage, p53 induction of the Caspase-2-PIDDosome creates a positive feedback loop that inhibits Mdm2 and reinforces p53 stability and activity, contributing to cell survival and drug resistance. These data establish Mdm2 as a novel cleavage target of Caspase-2 and provide insight into a mechanism of Mdm2 inhibition that impacts p53 dynamics upon genotoxic stress. Our current goals are to: 1) elucidate how cleaved Mdm2 dictates p53 function and 2) create mouse models to manipulate Mdm2 cleavage in vivo in order to interrogate the role of Mdm2 cleavage in lung tumorigenesis and drug response.
The nature of perceived authority in the milgram paradigm: Two replications

Thirty-eight college students watched a short, edited version of Milgram’s documentary film, Obedience. They were then randomly assigned to one of two responseconditions: A Choice condition, in which they chose one of six explanations for the compliance of a subject depicted in the film, or a Likelihood condition, where they used a Likert-type scale to indicate the likelihood that each explanation elicited the subject’s compliance. The six explanations were based on French and Raven’s (1959) constructs regarding the bases of social power. We found that expert and legitimate power were judged as the most likely explanations in both conditions, replicating the findings of an earlier study that had used a different response format, i.e. rankordering the explanations, and thereby verifying the generality and robustness of the phenomenon.
The in vitro transmission frequency of the t6 allele.

The T region, located on chromosome 17 in the mouse, is a complex genetic locus which includes a series of recessive mutations, tn (refs 1, 2). These mutations include several alleles (also referred to as t-haplotypes2) which are embryonic lethals (tL). An additional phenotypic expression of the recessive lethal mutations is a distorted transmission of the t allele by the heterozygous male parent. Most T/tL and +/tL males transmit the recessive mutation to over 50% of their offspring. Two conditions are known to modify significantly the transmission frequency of some tL alleles: the length of time between insemination and fertilisation3–5 and the genetic background of the female6. The present studies were undertaken to determine if the distorted transmission frequency of one of the lethal alleles, t6, could be reproduced in vitro. The data show that the in vitro transmission frequency of the t6 mutation is non-mendelian and is not significantly different from the frequency of transmission of this mutation following in vivo delayed matings. The in vitro frequency is, however, significantly lower than the normal mating frequency and does not vary as a function of incubation time. These data suggest that the observed delayed and normal mating frequency differences result from time-dependent interactions between the t6-bearing spermatozoon and the female reproductive tract.
Chromosomal abnormalities among welder trainees

Abstract Serial cytogenetic observations were made on a group of 273 military recruits who were being trained as welders at Aberdeen, MD. The trainees were being exposed to presumably increased levels of ozone in the course of their welding school experience, and it was the purpose of this study to determine whether or not ozone, at low-to-moderate doses, is capable of inducing chromosomal aberrations in peripheral blood lymphocytes. Previous exposures and the past medical experiences of the trainees were determined by questionnaire, enabling us to obtain a profile on the medical-social characteristics of the study sample. Each welder was to serve as his own control, having a blood sample drawn at the beginning of his twelve week training program, prior to ozone exposure, with two post-exposure bloods being obtained at 6 and 12 weeks after the start of the program. Ozone levels and the levels of the oxides of nitrogen were determined in the immediate area of the welding. The ozone levels were repeatedly found to be negligible, with the nitrogen oxides appearing to be the primary toxic agents involved. For those 165 subjects on whom two blood samples were obtained, and for those 86 on whom all three blood samples were obtained, no statistically significant increases in chromosomal aberrations were found.
Silicon Etching in Rapid Thermal Chemical Vapor Deposition of Tisi2

Downscaling of microelectronics devices into the deep submicron regime requires ultrashallow junctions with reliable, low-resistivity contacts. The conventional self-aligned TiSi2 technology exhibits a serious limitation in forming contacts to ultra-shallow junctions due to silicon substrate consumption. Selective chemical vapor deposition of TiSi2 is being investigated because of its potential for overcoming this difficulty. In this process Si and Ti are supplied from the gas phase. The standard source gas for Ti has been TiCl4 while several gases including SiH4, Si2H6 and SiH2Cl2 are available for Si. The reports on this process indicate that optimized process conditions can deliver TiSi2 films without substrate consumption. Although this promise is significant, the deposition has a complicated chemistry involving processes such as silicon etching, silicon consumption or silicon pedestal deposition taking place along with TiSi2 deposition. Although, suppression of Si-substrate etching by excess H2 has been reported previously, a broad quantitative analysis has been lacking up until this reporting. In this work, we have examined silicon etching trends as a function of temperature for different H2:TiCl4 flow ratios using thermodynamic equilibrium calculations. We have also performed experiments in a lamp heated rapid thermal chemical vapor deposition reactor to study substrate etching over the temperature range of 600°C to 800°C and for H2 flows from 0 to 1000 sccm. A silicon conversion efficiency is defined as a measure of the amount of Si converted to TiSi2 relative to total Si used from the substrate and it is evaluated via both thermodynamic calculations and experiments with good agreement between the two. Our calculations suggest that at high temperatures, etching occurs mainly via formation of SiCl2. Addition of H2 into the reaction chemistry encourages formation of HCl reducing the amount of Cl available for SiCl2 formation responsible for substrate etching. Our results show that by optimizing the H2 flow rate and the process temperature silicon substrate etching can be effectively suppressed.
The detection of organosphosphonates by polymer films on a surface acoustic wave device and a micromirror fiberoptic sensor

There is a need for sensitive detection of organophosphonates by inexpensive, portable instruments. Two kinds of chemical sensors, based on surface acoustic wave (SAW) devices and fiberoptic micromirrors, show promise for such sensing systems. Chemically sensitive coatings are required for detection, and data for thin films of the polymer polysiloxane are reported for both kinds of physical transducers. Both kinds of sensors are shown to be capable of detecting concentrations of diisopropylmethylphosphonate (DIMP) down to 1 ppm.
Correction of genetic disease by making sense from nonsense.

trophin-associated glycoprotein complex. Although gentamicin did not completely restore dystrophin levels, the level produced was sufficient to protect against contraction-induced injury. This presents a significant first step toward the use of these antibiotics in treating a broad class of genetic diseases resulting from nonsense mutations. Although gentamicin promotes translation read-through of the nonsense codon in dystrophin, it may also interfere with nonsense-mediated mRNA decay (6). All eukaryotic cells eliminate mRNAs that encode prematurely terminated products. This may protect cells from the production of nonfunctional or gain-offunction proteins. mRNAs that contain nonsense mutations more than 50 nucleotides upstream of the 3′-most exon-exon junction are selectively degraded by a process that requires protein synthesis. Stabilization of these mRNAs can occur if the ribosome translates through the termination codon (7, 8). The nonsense mutation in the mdx mouse reduces dystrophin mRNA levels to 10‐15% of normal (9). Therefore, the beneficial effects of gentamicin may result from dystrophin mRNA stabilization. It will be important to study dystrophin mRNA levels in the muscle tissues to determine if these drugs exert their action by stabilizing the nonsensecontaining mRNA. This appears likely, because gentamicin restored CFTR mRNA level in a cystic fibrosis (CF) bronchial epithelial cell line carrying a premature stop codon (3).
Relationship between Trauma and Risky Behavior in Substance-Abusing Parents Involved in a Family Dependency Treatment Court

This exploratory study examined participants in a Family Dependency Treatment Court (FDTC), designed for substance-abusing parents whose children were removed from the home. Twenty-five participants were interviewed one year after FDTC enrollment to assess retrospectively the relationship between trauma history and risky behaviors. Treatment compliance rates were found to be high, and most participants had negative urinalysis results. Qualitative analyses revealed that approximately half of the participants attributed decreases in risky behaviors to the FDTC program. This study increases understanding of the effect of substance abuse and trauma on high-risk behaviors and might help to improve services for substance-abusing parents involved in the child welfare system. Finally, the future success of reducing child abuse and neglect and parental substance use could hinge on the partnership between judicial and substance abuse treatment through FDTCs. Findings from this exploratory pilot study should be repl...
Testing the boundaries of the choice overload phenomenon: The effect of number of options and time pressure on decision difficulty and satisfaction

The number of alternatives available to people in many day-to-day decisions has greatly increased in Western societies. The present research sought to build upon recent research suggesting that having large numbers of alternatives can sometimes have negative consequences for individuals. In the present experiment, participants were presented with descriptions of either 3 or 10 prizes and asked to choose one, for which they were to be entered in a drawing. The number of alternatives was manipulated in conjunction with the amount of time people were allotted to make a decision (limited vs. extended decision time). Following their decisions, participants completed measures of decision-related difficulty, task enjoyment, satisfaction, and regret. Participants given a limited amount of time to choose with a larger set of alternatives found their decisions to be more difficult and frustrating than did participants in the other conditions. The larger set of alternatives led to less satisfaction, but not less regret, with people's decisions. Implications for research on the choice overload phenomenon are discussed. © 2009 Wiley Periodicals, Inc.
Cellular prion protein: A co-receptor mediating neuronal cofilin-actin rod formation induced by β-amyloid and proinflammatory cytokines

Increasing evidence suggests that proteins exhibiting "prion-like" behavior cause distinct neurodegenerative diseases, including inherited, sporadic and acquired types. The conversion of cellular prion protein (PrP(C)) to its infectious protease resistant counterpart (PrP(Res)) is the essential feature of prion diseases. However, PrP(C) also performs important functions in transmembrane signaling, especially in neurodegenerative processes. Beta-amyloid (Aβ) synaptotoxicity and cognitive dysfunction in mouse models of Alzheimer disease are mediated by a PrP(C)-dependent pathway. Here we review how this pathway converges with proinflammatory cytokine signaling to activate membrane NADPH oxidase (NOX) and generate reactive oxygen species (ROS) leading to dynamic remodeling of the actin cytoskeleton. The NOX signaling pathway may also be integrated with those of other transmembrane receptors clustered in PrP(C)-enriched membrane domains. Such a signal convergence along the PrP(C)-NOX axis could explain the relevance of PrP(C) in a broad spectrum of neurodegenerative disorders, including neuroinflammatory-mediated alterations in synaptic function following traumatic brain injury. PrP(C) overexpression alone activates NOX and generates a local increase in ROS that initiates cofilin activation and formation of cofilin-saturated actin bundles (rods). Rods sequester cofilin from synaptic regions where it is required for plasticity associated with learning and memory. Rods can also interrupt vesicular transport by occluding the neurite within which they form. Through either or both mechanisms, rods may directly mediate the synaptic dysfunction that accompanies various neurodegenerative disorders.
Software Infrastructure for an Autonomous Ground Vehicle

The DARPA Urban Challenge required robots to drive 60 miles on suburban roads while following the rules of the road in interactions with human drivers and other robots. Tartan Racing’s Boss won the competition, completing the course in just over 4 hours. This paper describes the software infrastructure developed by the team to support the perception, planning, behavior generation, and other artificial intelligence components of Boss. We discuss the organizing principles of the infrastructure, as well as details of the operator interface, interprocess communications, data logging, system configuration, process management, and task framework, with attention to the requirements that led to the design. We identify the requirements as valuable re-usable artifacts of the development process.
On the approximation of periodic solutions of equations with bounded nonlinearities

We present a method for obtaining a closed-form approximation to harmonic periodic solutions of a class of ordinary differential equations containing a bounded, Lipschitzian nonlinearity and a sinusoidal forcing term. Our technique replaces the continuous nonlinearity with a suitable step-function nonlinearity and uses the Phase-Shift-Averaging Method to write the solution of the piecewise-linear problem in closed form.
Impact of work teams: a comparison study of assembly cells and assembly line for a variety of operating environments

This research compares assembly lines with different cellular, team working environments. Organization of an assembly system using cells requires worker flexibility where each worker is allowed to help his or her co-workers in the same cell and often to undertake a number of different tasks within the cell. We compare two different cellular systems with an unpaced, serial assembly line. The manufacturing systems are initially compared through an exploratory Markovian approach. Subsequently, the relative performance levels of the systems are examined across a variety of operating environments using simulation models. Operating environments vary based on shop size, setup times and processing time variances. The results indicate the general superiority of the cellular systems over the assembly line. However, some interesting observations are drawn for cases where the assembly line outperforms the cells. One of the cases is where workers realize substantial benefits in terms of performing their tasks in less ...
Potentiation of antitumor CTL response by GM-CSF involves a B7-dependent mechanism.

Abstract We have previously demonstrated the importance of endogenous GM-CSF production for the B7-2-dependent potentiating effect of exogenous TNF for CTL generation by stimulation cultures of splenic cells from mice bearing a large MOPC-315 tumor. Here we show that addition of GM-CSF to stimulation cultures of such tumor-bearer splenic cells also leads to the generation of enhanced anti-MOPC-315 CTL activity via a B7-dependent mechanism. However, while the potentiating effect of TNF was previously shown to be IL-2-independent, the potentiating effect of GM-CSF is shown here to be completely IL-2-dependent. Still, the potentiating activity of exogenous GM-CSF for the in vitro generation of CTL activity is shown to depend completely on endogenous TNF production. Finally, TNF and GM-CSF may cooperate in enhancing the in vivo generation of CTL activity in MOPC-315 tumor bearers because low-dose melphalan ( l -phenylalanine mustard) therapy, which was previously shown to lead to the rapid up-regulation of TNF production at the tumor site and the subsequent TNF-dependent in vivo acquisition of potent CTL activity, is shown here to lead to the rapid up-regulation of GM-CSF production at the tumor site.
Applications with multiple parallel flows: Assessing their unfair advantage with proportional fair sharing TCP

We seek to understand proportional fairness in equi- librium in the presence of both applications with multiple flows (MFAs) and traditional applications with single flows (SFAs). Proportional fairness is shown to be applicable to TCP variants such as TCP Reno, TCP Vegas, and FAST TCP. We consider the competing scenario where an SFA with proportionally fair sharing TCP is competing with an MFA that invokes a number of parallel flows, also with proportional fair sharing TCP. We present analytical results for a linear network, and show the extent of the quantitative gain of an MFA can over an SFA regardless of whether it is connecting the far end of a linear network or just the adjacent nodes. I. INTRODUCTION
Self-reinforcement: An assessment of external influences

Two experiments were carried out in which low- and high-demand characteristics of self-reward were assessed in a multiple-baseline design across subjects. In the first experiment, arithmetic performance of four children was systematically assessed under no-reinforcement, self-reward/low-demand and self-reward/high-demand phases. In the second experiment, the performance of four children on a less meaningful task was assessed under the same conditions employed in Experiment 1. Results indicated that performance rates were relatively stable during the no-reinforcement phase but that these rates dropped markedly during the self-reward/low-demand phase for all eight subjects. Further, increased rates of performance were achieved under the self-reward/high-demand phase for all subjects. Results are discussed in terms of the assessment of the self-reinforcement procedure, current definitions of “self-reinforcement,” and the need to view self-reinforcement as existing on a continuum of external demand characteristics.
Generation of constitutively active p90 ribosomal S6 kinase in vivo. Implications for the mitogen-activated protein kinase-activated protein kinase family.

p90 ribosomal S6 kinases (RSKs), containing two distinct kinase catalytic domains, are phosphorylated and activated by extracellular signal-regulated kinase (ERK). The amino-terminal kinase domain (NTD) of RSK phosphorylates exogenous substrates, whereas the carboxyl-terminal kinase domain (CTD) autophosphorylates Ser-386. A conserved putative autoinhibitory alpha helix is present in the carboxyl-terminal tail of the RSK isozymes (697HLVKGAMAATYSALNR712 of RSK2). Here, we demonstrate that truncation (Δα) or mutation (Y707A) of this helix in RSK2 resulted in constitutive activation of the CTD. In vivo, both mutants enhanced basal Ser-386 autophosphorylation by the CTD above that of wild type (WT). The enhanced Ser-386 autophosphorylation was attributed to disinhibition of the CTD because a CTD dead mutation (K451A) eliminated Ser-386 autophosphorylation even in conjunction with Δα and Y707A. Constitutive activity of the CTD appears to enhance NTD activity even in the absence of ERK phosphorylation because basal phosphorylation of S6 peptide by Δα and Y707A was ∼4-fold above that of WT. A RSK phosphorylation motif antibody detected a 140-kDa protein (pp140) that was phosphorylated upon epidermal growth factor or insulin treatment. Ectopic expression of Δα or Y707A resulted in increased basal phosphorylation of pp140 compared with that of WT, presenting the possibility that pp140 is a novel RSK substrate. Thus, it is clear that the CTD regulates NTD activity in vivo as well as in vitro.
Cholesterol uptake by L5178Y tissue culture cells: studies with delipidized serum.

Abstract The uptake of free cholesterol by tissue culture cells (L5178Y) has been studied in a system using delipidized rabbit serum protein as the carrier of free cholesterol. The addition of phospholipids together with the free sterol reduces the adsorption of free cholesterol during a 5-h incubation period. Various purified phospholipids differed in effectiveness, sphingomyelin being the most effective in reducing free cholesterol uptake, followed by lecithin > phosphatidyl ethanolamine > phosphatidyl serine. Lysolecithin, at low concentrations, stimulated uptake slightly; at higher concentrations there was inhibition. In additional experiments, the addition of cholesterol plus various free fatty acids or glycerides to the delipidized protein affected free cholesterol adsorption by the cells. The influence of these compounds was not as pronounced as that of phospholipid. The uptake of cholesterol by L5178Y cells was influenced by the concentration of free cholesterol, phospholipids and protein in the culture medium.
Electron transfer in quinoproteins.

Soluble quinoprotein dehydrogenases oxidize a wide range of sugar, alcohol, amine, and aldehyde substrates. The physiological electron acceptors for these enzymes are not pyridine nucleotides but are other soluble redox proteins. This makes these enzymes and their electron acceptors excellent systems with which to study mechanisms of long-range interprotein electron transfer reactions. The tryptophan tryptophylquinone (TTQ)-dependent methylamine dehydrogenase (MADH) transfers electrons to a blue copper protein, amicyanin. It has been possible to alter the rate of electron transfer by using different redox forms of MADH, varying reaction conditions, and performing site-directed mutagenesis on these proteins. From kinetic and thermodynamic analyses of the reaction rates, it was possible to determine whether a change in rate is due a change in ΔG0, electronic coupling, reorganization energy or kinetic mechanism. Examples of each of these cases are discussed in the context of the known crystal structures of the electron transfer protein complexes. The pyrroloquinoline quinone (PQQ)-dependent methanol dehydrogenase transfers electrons to a c-type cytochrome. Kinetic and thermodynamic analyses of this reaction indicated that this electron transfer reaction was conformationally coupled. Quinohemoproteins possess a quinone cofactor as well as one or more c-type hemes within the same protein. The structures of a PQQ-dependent quinohemoprotein alcohol dehydrogenase and a TTQ-dependent quinohemoprotein amine dehydrogenase are described with respect to their roles in intramolecular and intermolecular protein electron transfer reactions.
End of life care: history and the role of the obstetrician and gynaecologist

In obstetrics and gynaecology we care for women who will die during pregnancy, for women who have fatal diseases such as autoimmune diseases or renal, liver, or cardiac failure where our care is tangential but critical to palliation, and for women dying with gynaecological malignancies. Understanding the history of the development of hospice and palliative care, as well as the ethical framework for these choices, may allow us to understand better the difficulties we face in our modern settings in making the choice to turn our goals from prolonging life to maximal comfort on the path to death. Obstetrician gynaecologists have a responsibility to be a voice of advocacy for maximal palliative care for not only the women they care for, but also for women worldwide because of their diminished social status and poverty.
The effect of in vitro and in vivo lead intoxication on monosaccharide transport in isolated rat brain microvessels

Abstract The effect of lead on facilitated transport of monosaccharides into isolated brain microvessels was investigated. Preparations from control rats and from rats exposed to lead acetate at various doses (0.025–1.0 mg lead/g body wt/day) from days 5–25 postnatally were studied. The time courses of uptake for various concentrations of 3-O-methylglucose (3OMG) were determined. Values of 0.6 min and 2.0 min for 5 and 50 mM 3OMG, respectively, were obtained in the case of preparations from control animals. In contrast, the half-time of uptake was about 1 min for both sugar concentrations for microvessels isolated from animals treated at 1.0 mg lead/g body wt/day. This indicates both a block in facilitated transport of the sugar, as well as damage to the endothelial cells resulting in increased passive permeability. There was a dose-response relationship for the effect of in vivo lead treatment on 3OMG transport in isolated microvessels. Microvessel preparations from younger animals (treated at 1.0 mg/g body wt for two days prior to sacrifice at 7 days postnatally) were more sensitive to lead treatment than preparations from adults; equivalent lead burden induced a greater increase in passive permeability to 3OMG in the younger animals. In other experiments microvessels isolated from untreated rats were preincubated with lead acetate. A concentration of 0.1 μM lead acetate in vitro abolished facilitated transport of 3OMG.
A TCP offload accelerator for 10 Gb/s Ethernet in 90-nm CMOS

This programmable engine is designed to offload TCP inbound processing at wire speed for 10-Gb/s Ethernet, supporting 64-byte minimum packet size. This prototype chip employs a high-speed core and a specialized instruction set. It includes hardware support for dynamically reordering out-of-order packets. In a 90-nm CMOS process, the 8-mm/sup 2/ experimental chip has 460 K transistors. First silicon has been validated to be fully functional and achieves 9.64-Gb/s packet processing performance at 1.72 V and consumes 6.39 W.
Evaluation of hematuria

A basic problem in evaluating hematuria is the large number of diagnostic possibilities. The causation may be suspected after the initial history and physical examination, and can be confirmed with appropriate studies. The addition of standard tests such as urine culture, intravenous pyelography, and cystoscopy will reveal the source of hematuria in many other cases and will bring the percentage of patients with a clear diagnosis up to 60 or 70 per cent. The physician must be careful in selecting further studies in the remaining patients, since the procedures necessary for diagnosis may be expensive, unpleasant, and potentially harmful, and the probability of finding a treatable condition is low. The diagnostic protocol described in this article is designed to reduce the studies performed to a minimum, while still identifying those individuals who can benefit from therapy.
Two-equation thermodynamical model for turbulent buoyant flows. Part I: theory

Abstract The derivation of a two-equation turbulence model consistent with the second law of thermodynamics that takes into account the effects of buoyancy to within the Boussinesq approximation is presented. The equations of conservation of mass, balance of momentum, conservation of energy, and entropy inequality are averaged, and the corresponding balance laws for the mean turbulent buoyant flow field are developed. The physical constraints imposed by the second law of thermodynamics are used to formulate the constitutive equations (or closure assumptions) for the turbulent stress tensor, the heat flux vector, and the energy flux vector. It is shown that the model has the capability of predicting nongradient heat diffusion. The new model contains empirical constants that are determined via comparison of analytical solutions of limiting turbulent flows with experimental data. Furthermore, with certain simplifications the model equations reduce to those of the common k-ϵ model for turbulence with added buoyancy terms.
Immune Hypersensitivity in Intensively Cultured Tilapia Species

Abstract Tilapia mossambica maintained at high densities in an intensive-culture tank system displayed hypersensitivity to a component present in mucus and culture water. The component induced cutaneous anaphylactic reactions in T. mossambica and three other Tilapia species, but did not affect Ictalurus punctatus. Gel filtration studies revealed the component to be high molecular weight (larger than 8 × 105 daltons) which electrophoretically migrated as a beta globulin. The component recovered from tank water of T. mossambica was not found in T. aurea tank water or in the incoming water. Tilapia mossambica experience higher mortality due to this autoimmune reaction, which limits the density at which this species can be stocked. Because the compound affects several species within the Tilapia genus, its effects should be considered when tilapias are stocked in fish culture operations.
Organometallic consequences of a redox reaction: Terminal trimethylsilylmethylidene titanium complexes prepared by a one-electron oxidation step

Abstract One-electron oxidation of the titanium(III) bis-trimethylsilylmethyl complex (nacnac)Ti(CH2SiMe3)2 (1) (nacnac− = [ArNC(Me)]2CH, Ar = 2,6-iPr2C6H3), readily prepared from (nacnac)TiCl2(THF) and 2 equiv. of LiCH2SiMe3 in Et2O, with AgOTf results in formation of the five-coordinate and terminal titanium alkylidene complex (nacnac)Ti CHSiMe3(OTf)(THF) (2)-THF concurrent with extrusion of tetramethylsilane and precipitation of silver metal. Complex 2-THF eliminates THF slowly under dynamic vacuum to generate the four-coordinate alkylidene 2 along with some decomposition products. Alternatively, the four-coordinate and non-solvento alkylidene complex, 2, can be prepared from 1 and AgOTf in pentane. Complex 2 undergoes cross-metathesis transformation to afford [ArNC(Me)CHC(Me) CHSiMe3]Ti NAr(OTf) (3) as the major product after 34 h at room temperature. Complexes 1, 2, 2-THF, and 3 have been fully characterized spectroscopically, and single crystal X-ray diffraction analysis for 1 and 2-THF are presented.