cssi/SciSciGPT-SciSciNet huggingface dataset:
Studies on the Role of Reactive Oxygen Species in Mediating Lipid Peroxide Formation in Epidermal Microsomes of Rat Skin

The role of superoxide, hydrogen peroxide, and singlet oxygen in mediating nonenzymic and NADPH-supported enzymic lipid peroxidation in skin microsomes was investigated. Incubation of skin microsomes with NADPH and/or Fe +3 -ADP or ascorbate resulted in the formation of lipid peroxides. The epidermis was the major target site for microsomal lipid peroxide formation in skin. Enzymic peroxidation of epidermal microsomes required NADPH and was oxygen-dependent. Addition of the nonenzymic catalysts, Fe +3 and ADP, to the enzymic peroxidation system had an additive effect on the generation of lipid peroxide in epidermal microsomes. Epidermal microsomal lipid peroxidation was inhibited by singlet oxygen quenchers such as dimethylfuran, histidine, and β-carotene. Hydroxyl ion scavengers such as mannitol, benzoate, or ethyl alcohol and the enzymic scavenger of superoxide, superoxide dismutase, were all ineffective in this respect. Addition of EDTA, Mn +2 , cytoehrome c +3 , and catalase to the NADPH-supported enzymic peroxidation system resulted in strong inhibition of lipid peroxide formation in skin. Glutathione or epidermal cytosol added alone or in combination to the NADPH-supported incubation system enhanced peroxidation of microsomal lipids. Vitamin E (α-tocopherol) inhibited lipid peroxidation. These results indicate that singlet oxygen may mediate lipid peroxide formation in epidermal microsomes.
The use of benzedrine and dexedrine sulfatein the treatment of epilepsy

Summary 1. Eighty-five epileptic patients, mostly children, were treated with benzedrine or dexedrine sulfate; the seizures were controlled in 38 per cent and markedly or moderately improved in 20 per cent. 2. These drugs were more effective in controlling petit mal than grand mal seizures. 3. There was no difference in the results in idiopathic and organic epilepsy.
Velocity Analysis by Perturbation

Abstract : Prestack depth migration provides a powerful tool for doing velocity analysis in complex media. Both prominent approaches to velocity analysis-- depth-focusing analysis and residual-curvature analysis, rely on approximate formulas in order to estimate velocity errors. Generally, these formulas are derived under the assumptions of horizontal reflector, lateral velocity homogeneity, or small offset. Therefore, the conventional methods for updating velocity lack sufficient computational efficiency when velocity has large, lateral variations. Here, using a perturbation method, we derive an analytic relationship between residual moveout and residual velocity. In our derivation, we impose no limitation on offset, dip, or velocity distribution. Based on this formula, we revise the residual-curvature-analysis method for velocity estimation that involves recursion and iteration. Furthermore, this formula provides the sensitivity and error estimation for migration-based velocity analysis, which is helpful in explaining the reliability of the estimated velocity.
σ70-dependent Transcription Pausing in Escherichia coli

After promoter escape in Escherichia coli, the initiating σ(70) factor is retained by core RNA polymerase (RNAP) for at least tens of nucleotides. While it is bound, σ(70) can engage a repeat of a promoter DNA element located downstream of the promoter and thereby induce a transcription pause. The σ(70)-dependent promoter-proximal pause that occurs at all lambdoid phage late gene promoters is essential to regulation of the late gene operons. Several, and possibly many, E. coli promoters have associated σ(70)-dependent pauses. Clearly characterized σ(70)-dependent pauses occur within 25 nucleotides of the start site, but σ(70)-dependent pausing might occur farther downstream as well. In this review, we summarize evidence for σ(70)-dependent promoter-proximal and promoter-distal pausing, and we discuss its potential regulatory function and mechanistic basis.
Neuropeptide Y receptor-expressing dorsal horn neurons: Role in nocifensive reflex responses to heat and formalin

Lumbar intrathecal injection of neuropeptide Y (NPY) is antinociceptive, particularly in models of nerve injury and inflammation. Intrathecal NPY does not alter nociception in mice null for the Y1 neuropeptide Y receptor (Y1R) and these mice show enhanced nocifensive reflex responses to aversive thermal, mechanical, visceral and chemical stimuli. Y1R and NPY receptor type 2 (Y2R) are present in the spinal dorsal horn presynaptically on primary afferent, and possibly interneuron terminals, but only Y1R is found postsynaptically on dorsal horn neurons. In the present study, we sought to assess the anatomic effects of lumbar intrathecal disulfide conjugate of neuropeptide Y and saporin (NPY-sap) and to determine the role of Y1R-expressing dorsal horn neurons in nocifensive responses to aversive thermal and chemical stimulation. Lumbar intrathecal injection of NPY-sap was used to selectively destroy Y1R-expressing lumbar dorsal horn neurons followed by testing nocifensive reflex responses on the hotplate and after hind-paw formalin injection. NPY-saporin decreased superficial dorsal horn staining for Y1R, but not neurokinin-1 receptor, mu opiate receptor or NPY peptide, and had no effect on Y1R cell counts in fourth lumbar spinal segment dorsal root ganglia. Loss of Y1R-expressing dorsal horn neurons was associated with increased first response latencies on the 44 degrees C hotplate and reduced total time rats spent licking and guarding hind paws during 600 s trials at 44 degrees C or 200 s trials at 47 degrees C. First hind-paw response latencies to high intensity phasic stimulation at 52 degrees C were unaffected. NPY-sap also reduced formalin-induced nocifensive behaviors during both interphase and phase II. These data demonstrate that selective destruction of Y1R-expressing superficial dorsal horn neurons, probably excitatory interneurons and/or projection neurons, reduces nocifensive reflex responses, particularly to activation of C nociceptors, and suggest a possible role for Y1R-expressing dorsal horn neurons in pain.
Integration of gene expression data with network-based analysis to identify signaling and metabolic pathways regulated during the development of osteoarthritis

Osteoarthritis (OA) is characterized by remodeling and degradation of joint tissues. Microarray studies have led to a better understanding of the molecular changes that occur in tissues affected by conditions such as OA; however, such analyses are limited to the identification of a list of genes with altered transcript expression, usually at a single time point during disease progression. While these lists have identified many novel genes that are altered during the disease process, they are unable to identify perturbed relationships between genes and gene products. In this work, we have integrated a time course gene expression dataset with network analysis to gain a better systems level understanding of the early events that occur during the development of OA in a mouse model. The subnetworks that were enriched at one or more of the time points examined (2, 4, 8, and 16 weeks after induction of OA) contained genes from several pathways proposed to be important to the OA process, including the extracellular matrix-receptor interaction and the focal adhesion pathways and the Wnt, Hedgehog and TGF-β signaling pathways. The genes within the subnetworks were most active at the 2 and 4 week time points and included genes not previously studied in the OA process. A unique pathway, riboflavin metabolism, was active at the 4 week time point. These results suggest that the incorporation of network-type analyses along with time series microarray data will lead to advancements in our understanding of complex diseases such as OA at a systems level, and may provide novel insights into the pathways and processes involved in disease pathogenesis.
Induction of an estrogen‐responsive reporter gene in rainbow trout hepatoma cells (RTH 149) at 11 or 18°C

The potential for temperature to influence estrogen-mediated responses in poikilothermicanimals suggested that temperature may be an important variable to consider when using an estrogen-responsive reporter gene in a rainbow trout cell line to test chemicals for estrogenic activity. Rainbow trout hepatoma cells (RTH 149) incubated at 11 or 18°C were cotransfected with an estrogen-responsive luciferase reporter plasmid and a plasmid containing a constitutively expressed rainbow trout estrogen receptor. The RTH-149 cells were then exposed to estradiol, with samples collected at 24-h intervals. The 72-h effective concentration for 50% maximal response (EC50) for estrogen-responsive luciferase activity at 11°C was 3.8 × 10−9 M and 7.4 × 10−10 M at 18°C. The efficacy of estradiol was lower at 11°C. The maximal response to estradiol in cells at 11°C was generally two- to threefold greater than controls (mean = 2.6-fold), whereas the maximal response at 18°C was three- to fourfold greater than controls (mean = 3.2-fold). Ethinylestradiol, a strong estrogen receptor agonist, was similar to estradiol in potency (relative potency = 0.8) and efficacy at the two temperatures. The EC50 of the weak estrogen receptor agonist 4-tert-pentylphenol was 7.6 × 10−7 M at 11°C and 6.9 × 10−7 M at 18°C; its potency relative to 17β-estradiol was not significantly different at the two temperatures, 0.00036 and 0.00054 at 11°C and 18°C, respectively. The estrogen-responsive reporter gene activity produced by 10−8 M estradiol was completely inhibited by the two estrogen hormone receptor antagonists, ZM 189,154 and ICI 182,780, at 10−6 M concentration of either antagonist. Although there may be slight differences in responses between the two temperatures tested here, this assay can be used to effectively determine the relative estrogenic activity of chemicals within the physiological temperature range of rainbow trout.
Simple model for the Bénard instability with horizontal flow near threshold.

We present a simple model for Rayleigh-B\'enard convection with an imposed horizontal flow of Reynolds number R in a container of finite width and near threshold. The model consists of two coupled envelope equations representing longitudinal and transverse traveling convection rolls. Each equation is for a wave traveling in the direction of the imposed flow. For small R, transverse rolls are stable at the convective onset. For Rg${\mathit{R}}^{\mathrm{*}}$, longitudinal rolls bifurcate from the conduction state. For a range of cross-coupling strengths and for Rg${\mathit{R}}^{\mathrm{*}}$, we obtain a transition from longitudinal to transverse rolls as the Rayleigh number is increased. This transition occurs via states for which part of the system is occupied by longitudinal, and another by transverse rolls. The behavior is strongly influenced by the presence of noise since the system first becomes convectively unstable, and therefore noise-sustained structures can play an important role. We also show that for a range of parameters in the model, a mixed state (for which both envelopes assume a nonzero value at the same location) is possible over part of the cell in a finite geometry.
Performance of constitutive models in predicting behavior of remolded clay

The performance of several soil constitutive models was evaluated by comparing experimental results and simulated behavior of a medium plasticity clay. Input parameters for the soil constitutive models were obtained from triaxial compression and extension tests on normally and overconsolidated medium plasticity clay. The soil models employed for this study were the Cam Clay, Modified Cam Clay, 3-SKH, and S-CLAY1 models. In order to investigate the influence of some of the input parameters on the performance of the models, sensitivity analyses were also performed. The comparisons demonstrate that the Cam Clay model was able to predict the normally consolidated compressive behavior of medium plasticity clay. Both 3-SKH and Cam Clay models were able to produce acceptable predictions for stress–strain and stress path behavior for overconsolidated compression of the soil. The 3-SKH model did not perform satisfactorily for predicting pore pressure variations, while the Cam Clay model demonstrated fairly acceptable predictions. For the normally consolidated reduced extension test, the Modified Cam Clay and S-CLAY1 models performed better than the Cam Clay and 3-SKH models in predicting the stress–strain curve, pore pressure variations, and stress path.
Study on the Virtual Instrument for Coaxiality Error

Used LabWindows/CVI as software platform, existing apparatus in laboratory and a data acquisition card as hardware platform, the virtual instrument for coaxiality error was developed. It combines the theory to measure form and position error with technology about virtual instrument. Coaxiality error by least square method and the minimum zone method is measured. The image of coaxiality error can be displayed on the screen to analyse the causes of error, so as to control the manufacturing error. The virtual instrument has the advantages of high precision, stablity, low manufacturing cost, especially the excellent function expandability. It can be used for experimental teaching and the actual production.
Athletic Trainers' Facilitators of Professional Commitment in the Collegiate Setting

Context: Professional responsibility, rewards and respect, and time for rejuvenation are factors supporting professional commitment for athletic trainers (ATs) in the high school setting. The inher...
Servant leaders inspire servant followers: Antecedents and outcomes for employees and the organization

Abstract Despite widespread adoption of servant leadership, we are only beginning to understand its true utility across multiple organizational levels. Our purpose was to test the relationship between personality, servant leadership, and critical follower and organizational outcomes. Using a social influence framework, we proposed that leader agreeableness and extraversion affect follower perceptions of servant leadership. In turn, servant leaders ignite a cycle of service by role-modeling servant behavior that is then mirrored through coworker helping behavior and high-quality customer service, as well as reciprocated through decreased withdrawal. Using a multilevel, multi-source model, we surveyed 224 stores of a U.S. retail organization, including 425 followers, 110 store managers, and 40 regional managers. Leader agreeableness was positively and extraversion was negatively related to servant leadership, which was associated with decreased follower turnover intentions and disengagement. At the group-level, service climate mediated the effects of servant leadership on follower turnover intentions, helping and sales behavior.
Synthesis and Reduction Kinetics of Sterically Shielded Pyrrolidine Nitroxides

A series of sterically shielded pyrrolidine nitroxides were synthesized, and their reduction by ascorbate (vitamin C) indicate that nitroxide 3, a tetraethyl derivative of 3-carboxy-PROXYL, is reduced at the slowest rate among known nitroxides, i.e., at a 60-fold slower rate than that for 3-carboxy-PROXYL.
Breast tumor detection using continuous wave light source

The detection of small amounts of indocyanine green (ICG) in small volumes would suggest its potential use in the detection of early breast tumors. While phased array has already shown its ability to sharply localize small amounts of ICG in the picomole region, the question has arisen, what would be the comparable sensitivity of continous light systems for the same purpose? If this were a comparable sensitivity, the advantages of the simplest of opto- electronic systems and the use of light intensity not limited to those available under FDA regulations for laser diodes could be realized. In this research work, we investigate two methods of enhancing the contrast agent between diseased and healthy tissue using low frequency amplitude modulated light sources. The first method exploits the symmetry between the left and right breast and the second exploits the cylindrical symmetry of the breast. Both effect are enhanced by the use of an injected contrast agent (ICG). Based on the theory and model study, several human subjects cases were studied in the Hospital of the University of Pennsylvania. The results show that the peak signal can get about 60 seconds after ICG injection through the vein and then will take few minutes to get back to the baseline. The half decay time and maximum (Delta) OD are dependent of the characteristics of the breast tissue.
The N-terminal extension of βB1-crystallin: identification of a critical region which modulates protein interactions with βA3- crystallin

The human lens proteins β-crystallins are subdivided into acidic (βA1-βA4) and basic (βB1-βB3) subunit groups. These structural proteins exist at extremely high concentrations and associate into oligomers under physiological conditions. Crystallin acidic-basic pairs tend to form strong heteromolecular associations. The long N-terminal extensions of β-crystallins may influence both homo- and heteromolecular interactions. However, identification of the critical regions of the extensions mediating protein associations have not been previously addressed. This was studied by comparing the self association and heteromolecular associations of wild-type recombinant βA3 and βB1 crystallins and their N-terminal truncated counterparts (βA3ΔN30 and βB1ΔN56) using several biophysical techniques including analytical ultracentrifugation and fluorescence spectroscopy. Removal of the N-terminal extension of βA3 had no effect on dimerization or heteromolecular tetramer formation with βB1. In contrast, the self association of βB1ΔN56 increased resulting in homotetramer formation and heteromolecular association with βA3 was blocked. Limited proteolysis of βB1 produced βB1ΔN47, which similar to intact protein formed dimers but in contrast showed enhanced heteromolecular tetramer formation with βA3. The tryptic digestion was of physiological significance, corresponding to protease processing sites observed in-vivo. Molecular modeling of the N-terminal βB1 extension indicates structural features which position a mobile loop in the vicinity of these processing sites. The loop is derived from residues 48-56 which appear critical for mediating protein interactions with βA3-crystallin.
Comparative performance analysis LTE and A-WCDMA

In order to keep an edge on enhanced competitiveness of 3G technology, the Third Generation Partnership Project (3GPP) set specific targets for the longterm evolution, including increased data rates, larger coverage footprint, and reduced latency. In combination these improvements reduce operator costs in typical traffic scenarios and also reduce overall infrastructure. This paper gives an overview of the basic radio interface evolution, with OFDM and multi-antenna solution, and presents results indicating to what extent these targeted improvements can be met. It is seen that the targets for aggregate throughput are comparable for Long-Term Evolution (LTE) and WCDMA combined with a multi-antenna system. Advanced WCDMA can achieve similar performance improvements with the use of MIMO antenna systems.
Sex roles, stress, and distress: A study of person by situation contingency

Literature on the relationship between sex roles and adjustment has suggested that masculine traits, rather than the androgynous interaction of masculine and feminine traits, are associated with positive adjustment. Studies with noncollege student populations, however, raise questions as to the generalizability of these findings. Suggestions that sex role traits are associated with particular defensive styles raise the possibility that the sex role-adjustment link is mediated by situational factors. The present study assessed sex role orientation, depression, hostility, and stress in 105 students of nursing. Femininity predicted positive vocational adjustment within the group, masculinity was associated with lower levels of depression, and femininity predicted lower hostility. Within the sex role orientations studied, androgynous nurses reported lower depression and vocational stress than their undifferentiated counterparts. It is suggested that feminine sex roles, promoting an internalization of threat, aid positive adjustment in settings marked by joint instrumental and interpersonal demands.
Dueling Kinases Regulate Cell Size at Division through the SAD Kinase Cdr2

Summary Cell size control requires mechanisms that integrate cell growth and division. Key to this integration in fission yeast is the SAD family kinase Cdr2, which organizes a set of cortical nodes in the cell middle to promote mitotic entry through Wee1 and Cdk1 [1–3]. Cdr2 is inhibited by a spatial gradient of the DYRK kinase Pom1 emanating from cell tips in a cell-size-dependent manner [2, 3], but how the Pom1 gradient inhibits Cdr2 activity during cell growth is unknown. Here, we show that Pom1 acts to prevent activation of Cdr2 kinase activity by the CaMKK Ssp1. We found that Ssp1 activates Cdr2 through phosphorylation of a conserved threonine residue (Thr166) in the activation loop of the Cdr2 N-terminal kinase domain both in vitro and in cells. The levels of this activating phosphorylation increased with cell-cycle progression, and genetic epistasis demonstrated that Ssp1 promotes mitotic entry through Cdr2. Intriguingly, Pom1 phosophorylated the C-terminal domain of Cdr2, and this modification reduced Cdr2-T166 phosphorylation by Ssp1. These findings show how activation of the conserved mitotic inducer Cdr2 is integrated with an inhibitory spatial gradient to ensure proper cell size control at mitosis.
Should surgical novices trade their retractors for joysticks? Videogame experience decreases the time needed to acquire surgical skills

Video game experience (VGE) has been identified as a possible predictive factor for surgical skill. We hypothesized that surgical novices with previous VGE would acquire new surgical skills faster than those without. Fourth-year medical students (M4) and first-year surgical residents (PG-1) completed a survey asking about standard demographic data and previous VGE. Gamers had high VGE, defined as more than 3 h per week of videogame playing. Nongamers had little or no VGE. Both groups trained to proficiency on two tasks (AcquirePlace and Traversal) of the MIST-VR simulator, with proficiency defined as meeting previously validated criteria on two consecutive trials. The number of trials required to achieve proficiency for each task was recorded. The 26 participants included 11 M4s and 15 PG-1s: 17 males (8 gamers/9 nongamers) and 9 females (3 gamers/6 nongamers), mean age 27.8 years. There were no differences in time to proficiency between the M4 and PG-1 residents, and there were no significant differences in the relative number of gamers per gender. All participants eventually met proficiency criteria. The 11 gamers reached proficiency more quickly than the 15 nongamers (median 0 trials versus 6 trials, p = 0.01). Gamers scored lower than nongamers on their initial attempts. Women overall took longer to reach proficiency than did men (median 10 trials versus 0 trials, p = 0.002). When stratified according to VGE, female nongamers took longer to reach proficiency than male nongamers (median 11 trials versus 1 trial, p = 0.006) but among gamers, there was no difference between females and males (median 0 trials versus 0.5 trials, NS). Previous VGE shortens time to achieve proficiency on two tasks on a validated surgical simulator. The possibility that VGE may ameliorate gender differences in length of time required to acquire surgical skills should be explored further.
‘Making names’: The cutting edge renewal of African art in New York City, 1985–1996

Abstract This paper reconstructs a turning point in the symbolic production of African art as a fine art genre, when a ‘new’ variant was filtered into the market. This process is seen as part of the overall struggle of ‘making names’ — enacted by critics, curators, and dealers — that structures recognition, results in artistic change, and reproduces central distinctions in the fine art world. Informed by Bourdieu's formulation of cultural fields, the study is grounded in numerous sources, including fieldwork observations, secondary data analyses, a review of more than three hundred exhibitions, and interviews with key art world agents. To begin, the social organization of the mid-1980s New York art market is outlined as a spatial economy of name recognition, broadly composed of three agonistic segments. Afterward, the incorporation of a new African art into organizational and discursive structures is examined as the outcome of ongoing struggles between competing ‘position-takings’. Symbolic and material exigencies within the art market motivating the selection of such works, as well as specific strategies used in framing them as creations of disinterested individuals, are also examined.
Report on the 2012 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting July 8¿14, 2012, Chicago, Il, USA

The 2012 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting was held from July 8 to July 14 in Chicago, IL, USA. On behalf of its Steering Committee, we are thankful to all of the attendees for their participation and scientific contributions, which resulted in the Symposium breaking numerous records. We received overwhelming positive feedback, and hope you benefited from many of the innovations of the 2012 Symposium, including the impressive plenary speakers at the Global Plenary Session and the Funding Opportunities Plenary Session. We strived to make the attendees and their families, rep resenting 54 countries, feel welcome. We provided numerous opportunities for interaction during the oral and poster sessions, the Opening Reception at the world-famous Art Institute of Chicago, the continental breakfasts before the plenary sessions, the soldout Awards Banquet, the Student/GOLD Reception luncheon, the Women-in-Engineering Reception at Navy Pier, and the various formal and informal meetings at the conference hotel. The conference hotel, the Sheraton Chicago Hotel & Towers, was selected because of its layout, which facilitated interaction among people by providing large common spaces and keeping all attendees sufficiently close to each other. The Hospitality Suite welcomed a record number of registered guests, and the first-ever program for children of those attending the Awards Banquet was a success.
Tough times at la brea: tooth breakage in large carnivores of the late pleistocene.

One million to two million years ago, most of today9s large, predatory mammals coexisted with larger extinct species, such as saber-toothed cats and giant running bears. Comparisons of tooth fracture frequencies from modern and Pleistocene carnivores imply that predator-prey dynamics and interspecific interactions must have been substantially different 36,000 to 10,000 years ago. Tooth fracture frequencies of four Rancho La Brea species—dire wolf, coyote, saber-toothed cat, and American lion—were about three times that of extant carnivores. Consequently, these findings suggest that these species utilized carcasses more fully and likely competed more intensely for food than presentday large carnivores.
OPERATING CONVENTIONAL INFANT VENTILATORS AT UNCONVENTIONAL RATES

We examined the effect of progressive increases in ventilator rate on delivered tidal (VT) and minute volumes (V), and the effect of changing peak inspiratory pressure (PIP), PEEP, and I:E at different ventilator rates. Five different pressure preset infant ventilators were studied using a pneumotachograph, airway pressure monitor, and lung simulator. As rates increased from 10 to 150 bpm, VT stayed constant until 25-30 bpm; then progressively decreased. In all, VT began to decrease when proximal airway pressure waves lost inspiratory pressure plateaus. As rates increased, V increased until 75 bpm; then leveled off; then decreased. Substituting Helium for Oxygen increased the ventilator rate at which this V plateau effect occurred. Increasing PIP consistently increased VT. Increasing PEEP decreased VT. At rates less than 75 bpm, I:E (inspiratory time) had little effect on VT or V. At rates above 75 bpm, inspiratory time became a prime determinant of delivered V.
Cyclical alternative exon splicing of transcription factor cyclic adenosine monophosphate response element-binding protein (CREB) messenger ribonucleic acid during rat spermatogenesis.

During spermatogenesis, the levels of cAMP in seminiferous tubules undergo stage-dependent cyclical fluctuations. We show that changes in cAMP levels are accompanied by alternative exon splicing of the RNA encoding the cAMP-responsive transcription factor CREB (cAMP response element-binding protein), expressed in both the Sertoli and germ cells. Exons Y and W are expressed exclusively in the testis, and they introduce stop codons into the normal protein coding frame of CREB. The splicing in of W was shown earlier to activate the internal translation of two alternative products of the CREB messenger RNA (mRNA) containing the DNA-binding domain (I-CREBs). The I-CREBs act as potent inhibitors of activator isoforms of CREB. The functions of the alternatively spliced exon Y are unknown. To investigate whether the splicing of exons W and Y is regulated during spermatogenesis, seminiferous tubules, isolated from adult rats, were dissected into segments representing different stages of the spermatogenic cycle and...
Binding of ARF and β-cop to Golgi membranes: Possible regulation by a trimeric G protein.

The binding of cytosolic coat proteins to organelles may regulate membrane structure and traffic. Evidence is presented that a small guanosine triphosphate (GTP)-binding protein, the adenosine diphosphate ribosylation factor (ARF), reversibly associates with the Golgi apparatus in an energy, GTP, and fungal metabolite brefeldin A (BFA)-sensitive manner similar to, but distinguishable from, the 110-kilodalton cytosolic coat protein beta-COP. Addition of beta gamma subunits of G proteins inhibited the association of both ARF and beta-COP with Golgi membranes that occurred upon incubation with guanosine 5'-O-(3-thiotriphosphate) (GTP-gamma-S). Thus, heterotrimeric G proteins may function to regulate the assembly of coat proteins onto the Golgi membrane.
Synthesis and solid-state NMR structural characterization of polysiloxane-immobilized phosphine-amine and phosphine-thiol ligand systems

Abstract Polysiloxane-immobilized phosphine ligand systems have been prepared by hydrolytic condensation of mixtures of Si(OEt)4 and (R′O)3Si(CH2)nPPh2 (n = 2, R′ = Me; n = 3, R′ = Et) Polysiloxane-immobilized phosphine-amine and phosphine-thiol ligand systems have been prepared by hydrolytic condensation of mixtures of Si(OEt)4, (R′O)3Si(CH2)nPPh2 (n = 2, R′ = Me; n = 3, R′ = Et) and (R′O)3Si(CH2)3X (X = NH2, R′= Et; X = NHCH2CH2NH2. R′ = Me) or (MeO)3Si(CH2)3SH. In the polysiloxane-immobilized phosphine-amine and phosphine-thiol systems two types of ligand groups are introduced into the polysiloxane matrix during the sol-gel process. Solid-state 13C, 31P and 29Si NMR spectroscopy was used to investigate the structures of the polysiloxane-immobilized ligand systems — e.g., to determine the presence of unhydrolyzed/uncondensed alkoxy groups, to determine the ratios of phosphine to phosphine oxide moieties, to determine details of the silicon-based backbone (relative populations of various types of RSi(-O-)3 and Si(-O-)4 moieties) and to establish domain homogeneity throughout a given material.
A phase field study of microstructural changes due to the kirkendall effect in two-phase diffusion couples

The phase field method was used to simulate the interdiffusion in ternary, two-phase diffusion couples. Model γ+γ′ alloys were designed so that changes in the microstructure could be attributed to either coarsening or the Kirkendall effect. For the model parameters adopted in the study, particle coarsening increased the average precipitate size, but it had little influence on the diffusion path. However, the Kirkendall effect, which was introduced by setting atomic mobilities to different values, changed the diffusion path slope and led to the formation of “horns” on the two-phase diffusion path. Although the results obtained were somewhat dependent on the model parameters, they demonstrate the value of the phase field method when studying complex interdiffusion problems.
Cyclic stress response characteristics of an aluminum–magnesium–silicon alloy

Abstract In this paper, the cyclic stress response characteristics of aluminum alloy 6061 is presented. Test specimens of the alloy were cyclically deformed using fully-reversed tension–compression loading under total strain amplitude control. The alloy showed evidence of initial hardening followed by progressive softening to failure. The stress response, deformation characteristics and fracture behavior of the alloy is interactively discussed in light of the competing influences of intrinsic microstructure contributions and deformation behavior arising from a combination of mechanical and microstructural contributions.
On the Heuristic Value of the Concept of Political Religion and Its Application

The usefulness of the concept of Political Religions (PR) in the modern world depends first of all on the definition of the term ‘religion’. Over a century ago Emile Durkheim established among sociologists and anthropologists the concept that religion consists essentially of the organisation of rites and rituals formed around a belief system aimed at buttressing social solidarity and morality. Thus, any strong ideology that was fully articulated and expressed socially might be considered a religion. This is the definition most commonly employed by those who use the concept of PR.
Hybrid reliability modeling of fault-tolerant computer systems

Abstract Current technology allows sufficient redundancy in fault-tolerant computer systems to insure that the failure probability due to exhaustion of spares is low. Consequently, the major cause of failure is the inability to correctly detect, isolate, and reconfigure when faults are present. Reliability estimation tools must be flexible enough to accurately model this critical fault-handling behavior and yet remain computationally tractable. This paper discusses reliability modeling techniques based on a behavioral decomposition that provides tractability by separating the reliability model along temporal lines into nearly disjoint fault-occurrence and fault-handling submodels. An Extended Stochastic Petri Net (ESPN) model provides the needed flexibility for representing the fault-handling behavior, while a nonhomogeneous Markov chain accounts for the possibly non-Poisson fault-occurrence behavior. Since the submodels are separate, the ESPN submodel, in which all time constants are of the same order of magnitude, can be simulated. The nonhomogeneous Markov chain is solved analytically, and the result is a hybrid model. The method of coverage factors, used to combine the submodels, is generalized to more accurately reflect the fault-handling effectiveness within the fault-occurrence model. However, due to approximations made in the aggregation of the two submodels and inaccurate estimation of component failure rates and other model parameters, errors can still arise in the subsequent reliability predictions. The accuracy of the model predictions is evaluated analytically, and error bounds on the system reliability are produced. These modeling techniques have been implemented in the HARP (Hybrid Automated Reliability Predictor) program.
Navigation Challenges of the Mars Phoenix Lander Mission

The Mars Phoenix Lander mission was launched on August 4th, 2007. To land safely at the desired landing location on the Mars surface, the spacecraft trajectory had to be controlled to a set of stringent atmospheric entry and landing conditions. The landing location needed to be controlled to an elliptical area with dimensions of 100km by 20km. The two corresponding critical components of the atmospheric entry conditions are the entry flight path angle (target: -13.0 deg +/-0.21 deg) and the entry time (within +/-30 seconds). The purpose of this paper is to describe the navigation strategies used to overcome the challenges posed during spacecraft operations, which included an attitude control thruster calibration campaign, a trajectory control strategy, and a trajectory reconstruction strategy. Overcoming the navigation challenges resulted in final Mars atmospheric entry conditions just 0.007 deg off in entry flight path angle and 14.9 sec early in entry time. These entry dispersions in addition to the entry, descent, and landing trajectory dispersion through the atmosphere, lead to a final landing location just 7 km away from the desired landing target.
Partial groups, doubly semi-direct products, and the decomposition of the spacetime diffeomorphism group

Abstract An initial value decomposition of the spacetime diffeomorphism group is performed using the notion of a doubly semi-direct product of groups and the notions of partial and local, groups and actions.
Self-Induced Multi-Resonances in Initially Opaque Plasma

An overdense plasma under the action of intense light can switch from full reflection to almost full transmission in a succession of nonlinearly self-induced resonances. This allowes for a deeper and more efficient plasma heating.
Developments and possibilities of optimization models

Abstract A review of the most common optimization procedure is performed, aiming at pointing out their main characteristics. Their application to the decision-making process where planning and operating complex water resource systems is described.
An Inverse Reliability-based Approach for Designing under Uncertainty with Application to Robust Piston Design

In this work, we propose an optimization framework for designing under uncertainty that considers both robustness and reliability issues. This approach is generic enough to be applicable to engineering design problems involving nonconvex objective and constraint functions defined in terms of random variables that follow any distribution. The problem formulation employs an Inverse Reliability Strategy that uses percentile performance to address both robustness objectives and reliability constraints. Robustness is achieved through a design objective that evaluates performance variation as a percentile difference between the right and left trails of the specified goals. Reliability requirements are formulated as Inverse Reliability constraints that are based on equivalent percentile performance levels. The general proposed approach first approximates the formulated problem via a Gaussian Kriging model. This is then used to evaluate the percentile performance characteristics of the different measures inherent in the problem formulation for various design variable settings via a Most Probable Point of Inverse Reliability search algorithm. By using these percentile evaluations in concert with the response surface methodology, a polynomial programming approximation is generated. The resulting problem formulation is finally solved to global optimality using the Reformulation---Linearization Technique (RLT) approach. We demonstrate this overall proposed approach by applying it to solve the problem of reducing piston slap, an undesirable engine noise due to the secondary motion of a piston within a cylinder.
Use of voltage sensitive dyes to investigate electrical defibrillation

An approach called voltage-sensitive-dye recording is introduced for the study of electrical defibrillation of the heart. Voltage-sensitive dyes (VSDs) are molecular probes which transduce cellular potential into an optical signal. Specifically, the optical signals produced by VSDs can be used to follow the time-course of cardiac action potentials. This style of recording is advantageous because the processes involved in the transduction of membrane potential are insensitive to the large extracellular electrical fields created by defibrillating shocks. Thus it is possible to observe both the changes in membrane voltage imposed by the passage of shock current and the subsequent electrophysiological responses of the myocardium. >
Methodology for Estimation of Days Dry Effects

The primary objective of this research was to determine if, with appropriate methodology, unbiased estimates of days dry (DD) effects on subsequent lactation milk yield can be obtained from field data, particularly when DD is correlated with cow effects. Another objective was to ascertain relevant sampling properties of designed trials for estimation of DD effects. Simulated records were used to assess methodology. Along with a model with no adjustments for cow effects, alternative models including 1) previous lactation milk yield, 2) a prior adjustment for cow effects estimated from an animal model, and 3) a combination of 1 and 2, were tested. Estimates from the unadjusted model were biased downward; however, the 3 alternative analyses provided estimates of DD effects that were essentially unbiased, with a prior adjustment for cow effects and previous milk yield in the model providing the best results in terms of elimination of bias. Therefore, DD effects can be estimated from field data without bias from cow effects.A designed trial with 2 groups and 10 or fewer cows/ group is noninformative and has an unacceptably high probability of leading to invalid conclusions. A minimum of 30 cows/group is considerably better and should be used whenever possible. Even with 30 cows/group, however, the power is low unless the difference between DD groups for yield is at least 1130 kg. Prior correction of 305-d, mature equivalent records for cow effects, using predicted producing abilities, could be done in designed trials to improve the statistical power of tests and accuracy of estimates.
Occurrence of pregnancy, abortion, and artificial menopause among women with coronary artery disease: a preliminary study.

Abstract 1. 1. An analysis of the age-sex-specific mortality rates from arteriosclerotic heart disease, including coronary disease, on a semilogarithmic scale, indicated that prior to 40 to 45 years of age the male slope was greater than that of the female. After this age, the ratio of these two slopes decreased. This was interpreted as being a result of endocrine changes that occur at this period of life. 2. 2. Fifty female patients with clinically confirmed myocardial infarction have been compared with 50 paired controls and 149 probability sample controls with respect to pregnancy, live birth, stillbirth, abortion, and artificial menopause experience. 3. 3. Patients had an excess of abortion, total pregnancies, and artificial menopause. The excess abortion and artificial menopause experience of patients was interpreted as being consistent with the hypothesis that endocrine factors play an etiologic role in coronary heart disease. In interpreting the results in this manner, emphasis was placed on the consistency of the pattern of the observations. The excess of total pregnancies among patients was interpreted as an effort to compensate for excess fetal loss due to abortions.
Ammonia, oxidation leaching of chalcopyrite —surface deposit effects

The reaction for the ammonia, oxidation leaching of chalcopyrite, CuFeS2 + 4NH3 + 17/4 O2 + 2 OH- = Cu(NH3)4 +2 + l/2Fe2O3 + 2 SO4 + H2O was studied using monosize particles in an intensely stirred reactor at moderate oxygen pressures. For dilute solids concentration, the rate is controlled by an electrochemical surface reaction. Under conditions of low stirring speeds and low oxygen pressure, the hematite reaction product passivates the surface and the reaction virtually stops. Even though stirring speed influences the rate of the electrochemical reaction, this effect is due to changes in the morphology of the hematite deposit which alters the surface reaction kinetics, rather than being indicative of mass transfer limitations.
DNA Binding and ToxR Responsiveness by the Wing Domain of TcpP, an Activator of Virulence Gene Expression in Vibrio cholerae

Virulence in Vibrio cholerae requires activation of toxT by two membrane-localized activators, TcpP and ToxR. We isolated 12 tcpP activation mutants that fell into two classes: class I mutants were inactive irrespective of the presence of ToxR, and class II mutants exhibited near wild-type activity when coexpressed with ToxR. Most class I mutants had lesions in the wing domain predicted by homology with the winged helix-turn-helix family of activators. Class I mutants bound promoter DNA poorly and were largely unable to interact with ToxR in a crosslinking assay, whereas class II mutants retained physical interaction with ToxR. One mutant constructed in vitro bound DNA poorly but nevertheless responded to ToxR by activating toxT and also maintained ToxR interaction. We propose that ToxR interaction, but not DNA binding, is essential for TcpP function and that the wing domain of TcpP enables contact with ToxR required for productive TcpP-RNA polymerase association.
Plant reestablishment 15 years after the debris avalanche at Mount St Helens, Washington

Vegetation has slowly reestablished on the debris avalanche deposit in the 15 years after the 1980 eruption of Mount St. Helens that created a 60-km(2) debris avalanche, the largest landslide in recorded history. There has been a gradual increase in species richness and cover, but only 61% of the species present on the mountain before the eruption have established on the debris avalanche deposit. Plant cover averages 38% and is extremely patchy. Life form composition changed over successional time, because part of the avalanche deposit was invaded by introduced plant species aerially seeded to reduce erosion, the site offers the opportunity to compare successional processes occurring with and without introduced species. Long-term recovery trends and effects of nonnative species on succession are important to understand since plant reestablishment practices often rely on nonnative species for enhancing vegetation recovery of denuded sites along road sides, strip mines, or other human-generated clearing. Fifteen years after the eruption and 10 years since the invasion by introduced species, plots invaded by nonnative species had greater vegetation cover and more native plant richness than plots that were not inundated. Significantly greater mortality of conifers occurred in the plots dominated by introduced species shortly after the invasion of those species, but no difference in conifer mortality occurred in the last 5 years. Even so, the plots dominated by introduced species still have fewer conifer trees. Thus, the short-term pulse of conifer mortality after the invasion of introduced species may have long-term effects on the recovery of the dominant vegetation. It will likely be decades before there is 100% plant cover on the debris avalanche deposit and a century or more before full recovery of the vegetation system.
Selective dissociation of histones from chromatin by sodium deoxycholate

Abstract Ionic agents such as NaCl or HCl which dissociate histones from DNA remove Iysine-rich histones I at lowest concentrations of the dissociating agent. We have found that the less polar agent, deoxycholate, dissociates histones II from DNA at lower concentrations of the dissociating agent than are required for dissociation of other histones. This finding has proved to be useful in establishing which histones confer which properties upon DNA-histone complexes such as chromatin.
Gamma-ray lines from SN1987A

Results of gamma-ray observations of SN1987A conducted over a period of 800 days using balloon-borne high-resolution germanium detectors are discussed. Most of the measurements show red-shifted line centroids (about 500 km/s) and broadened profiles, contradicting the standard homogeneous and spherically symmetric models, which predict blue-shifted lines and narrower line widths. To explain this apparent contradiction, it may be necessary to invoke fragmentation and nonspherical geometries.