cssi/SciSciGPT-SciSciNet huggingface dataset:
Loss of gelation ability of Pluronic® F127 in the presence of some salts

Abstract In this investigation, we show that certain salts with multivalent anions, at characteristic concentrations, prevent Pluronic® F127 solutions from forming gels. This was done by measuring the gel formation (T1), gel melting (T2) and cloud point (Tcp) transitions of 20% Pluronic® F127 gels in the presence of various such salts. All the salts studied lower all three transition temperatures. The degree of lowering is proportional to salt concentration and can be ascribed to salting-out effects. Both the cation and anion appear to influence T1, while T2 and Tcp are predominantly influenced by the salt anion. T1 is lowered because salts decrease the critical micelle concentration (cmc) of F127. The effect on T2 and Tcp parallels the precipitation of poly(ethylene oxide) from aqueous solution in the presence of salts and follows the Hofmeister series. Multivalent anions reduce T2 to a much greater extent than T1, and this results in a loss of gel formation above a certain ‘no-gel’ salt concentration.
Repeated Perfusion of Droplet-Interface Bilayers

The droplet-interface bilayer (DIB) is a recently-developed model cell membrane that is created at the contact between two sub-microliter lipid-encased aqueous droplets. The DIB is a promising approach in mechanistic studies of membrane transport, allowing the translocation of material to be monitored and quantified1. However, it is limited by the inability to introduce new reagents once the droplets are formed. Recently, Thompson and coworkers added reagents to a droplet through injection, after the bilayer formed between this droplet and a monolayer on a hydrogel2. Nevertheless, reagents could not be imported and removed repeatedly. Herein, we designed a fluid exchange device that replaces one of the droplets with a flowing system that allows reagents to be introduced and perfused continuously without rupturing the DIB. As a proof of concept, α-hemolysin (αHL), which assembles to form heptameric pores on cell membranes, and γ-cyclodextrin (γCD) that binds non-covalently to the lumen of αHL were used in the device. Specifically, αHL was placed in the droplet and γCD was added to and removed from a microliter, perfused volume to act as a representative membrane phenomenon to test the device. The observation of successive γCD blocking event upon introduction and the cessation of blocking events when the volume was perfused with buffer demonstrated that the fluid exchange on DIB could be completed repeatedly. We anticipate that this approach will be widely applicable and will broaden the utility of studies that require reconstituted membranes.(1) Huang, J.; Lein, M.; Gunderson, C.; Holden, M. A. Journal of the American Chemical Society 2011, 133, 15818-15821.(2) James R. Thompson; Brid Cronin; Hagan Bayley; Wallace∗, a. M. I. Biophysical Journal 2011, 101, 2679–2683.
Interleukin-6 in human milk

Interleukin-6 (IL-6) in human milk collected during the first 2 days of lactation was investigated by a competitive radioimmunoassay (RIA) and column chromatography. The concentrations of IL-6 in the aqueous phase of fresh human milk were 151 +/- 89 pg/ml. The concentrations of IL-6 in milk increased after storage at 4 degrees C and decreased after storage at -20 degrees C (P or = 100 kDa and the second between 25 and 30 kDa. The 25-30-kDa peak corresponded to known isoforms of human IL-6 and to the elution pattern for 125I-labeled recombinant human IL-6, whereas the higher molecular weight peak may be in keeping with a bound or compartmentalized form of that cytokine. The precise molecular forms of this protein, the compartmentalization of or binding proteins for this cytokine and the in vivo effects of IL-6 in human milk upon the mammary gland or the recipient infant remain to be explored.
A Study of the Association among Verbal Attitudes, Commitment and Overt Behavior in Different Experimental Situations

This study examined the paired associations among verbal attitudes, commitment and overt behavior. Overt behavior was measured by the degree to which students voluntarily became socially involved in a campus chapter of a civil rights organization. Verbal attitudes were found to be either consistent or inconsistent with overt behavior depending upon how the investigator structured the experimental situation in which verbal attitudes were measured. Stu dies examining racial attitudes and overt behavior have often reported inconsistency between the measure of verbal attitudes and overt behavior.' One explanation for the discrepancy is that characteristics of the overt sitiutinn. rather than attitudes. determine the action toward the attitude object.2 Another way of interpreting the findings involves the recognition that situational factors influence behavior in both measurement situations. When measuring verbal attitudes, the situational characteristics can be markedly different than characteristics in the overt situation. The disparity between the situational characteristics which influence respondents' role-playing in each setting may contribute to the inconsis-
Molecular assemblies for siRNA delivery

The chance to selectively intervene and stop the development of any gene-dependent disease in different organs and pathologies makes siRNA a potential therapeutic agent. However, serious issues remain to be addressed before the real therapeutic use of siRNA. The poor pharmacokinetic properties of siRNA, its short half-life, its low in vivo stability, its fast elimination by renal excretion and its low transfection efficiency complicate the use of siRNA as a therapeutic molecule. In this review, we will describe the latest and most advanced approaches and strategies undertaken to address these limitations and improve siRNA delivery and its gene-silencing efficacy as well as the prospects for its therapeutic application.
Using Past Performance, Proxy Efficacy, and Academic Self-Efficacy to Predict College Performance

This study examined the ability of prior academic performance, proxy efficacy, and academic self-efficacy to predict college academic performance. Participants (N = 202) completed a modified version of the Teacher Collective Efficacy scale (Goddard, 2001), the Academic Self-Efficacy scale (Elias & Loomis, 2000), and a demographic questionnaire. Prior performance was predictive of both academic self-efficacy beliefs and college performance. Hierarchical regression analysis indicates that academic self-efficacy beliefs explain a significant amount of unique variance beyond past performance in predicting college performance. Proxy efficacy did serve as a predictor of student academic self-efficacy, but did not serve as a predictor of college performance. Implications for instructors, as well as for future research, are discussed.
Feasibility of measuring phase relaxation time with subpicosecond pulses

Techniques to determine the phase relaxation time of absorbing dye solutions are evaluated. It is shown that, contrary to a recent paper by Cho et al., transmission of low intensity pulses cannot yield information on the relaxation of broad-band absorbing transitions.
Insulin and Obesity in the Zucker Genetically Obese Rat “Fatty”

Insulin status and functional activity have been studied during the life of the Zucker “fatty” rat (an obese mutant). Serum immunoreactive insulin (IRI) is normal at 2 weeks when fattening is beginning, rises to a peak of 400 μ-U/ml at 15 weeks while fattening proceeds rapidly, then drops to near 200 μU/ml in older rats. This was observed with two normal diets and a high protein diet. When fattening is reversed by fasting adult “fatties,” IRI remains abnormally high until body lipid has returned to normal (79 days). Blood sugar, basally and after a glucose load, is normal in young and old “fatties,” and is barely above normal at peak IRI. Sugar falls to below 50 mg/100 ml with prolonged fasting. Amino nitrogen tends to be slightly low, free fatty acids (FFA) are very high, in “fatties.” There is a developing resistance of diaphragm to glucose uptake in vivo, both basally and after injected insulin. The role of elevated FFA in this resistance to glucose uptake by muscle is not known. Basal glucose uptake i...
Electrochemical Activation Parameters of Coupled Electron-Transfer and Spin-Exchange Reactions. Experimental Studies of [M(Tacn)2]3+/2+ and [Fe(Pzb)2]+/0 Redox Systems

Expressions are derived for rate constants and activation parameters of electrochemical reactions that are accompanied by a change in spin-state. Predictions based on an electrochemical scheme of squares are compared with experimental results for [M(tacn)2]3+/2+ (M = Fe, Co, Ni, Ru; tacn = 1,4,7-triazacyclononane) and [Fe(pzb)2]+/0 (pzb- = hydrotris(pyrazol-1-yl)borate [HB(pz)3-], tetrakis(pyrazol-1-yl)borate [B(pz)4-] or hydrotris(3,5-dimethylpyrazol-1-yl)borate [HB(Me2pz)3-]) redox couples. The electrochemical rate constants, (ks,h)obs, of [Co(tacn)2]3+/2+ and [Fe{HB(Me2pz)3}2]+/0 are decreased by the presence of spin-exchange. Electrochemical enthalpies (ΔH‡obs) and entropies (ΔS‡obs) of activation, determined from the temperature dependence of (ks,h)obs under nonisothermal cell conditions, provide evidence regarding the mechanism of these reactions. [Co(tacn)2]3+/2+, [Fe(tacn)2]3+/2+, and [Fe{HB(Me2pz)3}2]+/0 exhibit values of ΔH‡obs and ΔS‡obs that are larger than anticipated for simple electron-tran...
Variables Affecting Choice of Language Learning Strategies by University Students.

Learning strategies are operations used by learners to aid the acquisition, storage, and retrieval of information (52). Outside of the language learning field, research comparing experts to novices indicates that experts use more systematic and useful problem-solving and native-language reading comprehension strategies.2 A similar finding occurs with more successful language learners as compared to less successful ones.3 Better language learners generally use strategies appropriate to their own stage of learning, personality, age, purpose for learning the language, and type of language.4 Good language learners use a variety of learning strategies, including cognitive strategies for associating new information with existing information in long-term memory and for forming and revising internal mental models; metacognitive strategies for exercising "executive control" through planning, arranging, focusing, and evaluating their own learning process; social strategies for interacting with others and managing discourse; affective strategies for directing feelings, motivations, and attitudes related to learning; and compensation strategies (such as guessing unknown meanings while listening and reading, or using circumlocution in speaking and writing) for overcoming deficiencies in knowledge of the language." Appropriate learning strategies help explain the performance of good language learners; similarly, inappropriate learning strategies aid in understanding the frequent failures of poor language learners and even the occasional weaknesses of
Quintasymptotic primes and four results of Schenzel

Abstract Let I be an ideal in a Noetherian ring R, let (I)a be the integral closure of I, and let S be a multiplicatively closed subset of R. Let T1, T2, and T3 be the topologies given by the filtrations {In RS ∩ R | n ≥ 1}, {In | n ≥ 1}, and {(In)a | n ≥ 1}. We g results due to Schenzel, characterizing when T1 is either equivalent or linearly equivalent to either of T2 or T3. The characterizations involve the sets of essential primes of I, quintessential primes of I, asymptotic primes of I, and quintasymptotic primes of I.
Mortality Related to Neoadjuvant Therapy and Surgery for Stage III Non–Small-Cell Lung Cancer

Abstract Background Neoadjuvant chemotherapy alone or with concurrent radiation is often used for stage IIIA non–smallcell lung cancer but is often tried in patients with stage IIIB and at times in patients with stage I or II disease. Newer neoadjuvant regimens would need to be compared with currently used programs to see if they increased toxicity. For such a comparison, a baseline estimate is needed of the mortality of currently used regimens. Patients and Methods In this review, we searched PubMed and associated references, and data on mortality were identified in 34 publications. Results The mortality of neoadjuvant chemotherapy or chemotherapy plus radiation has been estimated in 2015 patients was 0.7%, and the postsurgical mortality in 2195 patients was 4.3%. Conclusion These estimates might provide a benchmark for comparison for innovative trials.
Nonlinear excitation of long-trapped waves by a group of short swells

A nonlinear theory is presented for the resonance of long gravity waves trapped on an uneven bottom when a long packet of short swells is incident. By allowing the trapped wave to be comparable in amplitude to the incident swells, the transient evolution of trapped waves is studied from initial growth through maturity to final decay, for swell packets of finite duration. For a totally submerged ridge, it is found that, while the trapped waves are resonated by second-order periodic modulations of the swell envelope, energy transfer to short swells and nonlinear emission of long waves act as damping mechanisms to limit the amplification. Bottom friction is not qualitatively crucial and affects the results only quantitatively. For a closed beach, breaking of short swells is dealt with empirically but resonant modulation is still the primary factor in exciting surf beats.
Emerging roles for the BAI1 protein family in the regulation of phagocytosis, synaptogenesis, neurovasculature, and tumor development

While G-protein-coupled receptors (GPCRs) have received considerable attention for their biological activity in a diversity of physiological functions and have become targets for therapeutic intervention in many diseases, the function of the cell adhesion subfamily of GPCRs remains poorly understood. Within this group, the family of brain angiogenesis inhibitor molecules (BAI1-3) has become increasingly appreciated for their diverse roles in biology and disease. In particular, recent findings suggest emerging roles for BAI1 in the regulation of phenomena including phagocytosis, synaptogenesis, and the inhibition of tumor growth and angiogenesis via the processing of its extracellular domain into secreted vasculostatins. Here we summarize the known biological features of the BAI proteins, including their structure, proteolysis events, and interacting partners, and their recently identified ability to regulate certain signaling pathways. Finally, we discuss the potential of the BAIs as therapeutics or targets for diseases as varied as cancer, stroke, and schizophrenia.
Nuclear states of 143Pr

Abstract The energies and relative intensities of 21 gamma rays, emitted in decay of 143 Ce have been measured in detectors of Ge(Li). Gamma-gamma coincidence experiments have been performed, and beta-gamma coincidence studies have been carried out. Calculation of values of log ft of eight beta spectra has shown them to lie in the region of first forbiddenness. Eight excited nuclear energy states have been established in 143 Pr at 57, 351, 491, 722, 937, 1061, 1158 and 1382 keV. Possible spin values have been assigned to all these states. These excited states all have even parity.
Structural Insight into HIV-1 Restriction by MxB

The myxovirus resistance (Mx) proteins are interferon-induced dynamin GTPases that can inhibit a variety of viruses. Recently, MxB, but not MxA, was shown to restrict HIV-1 by an unknown mechanism that likely occurs in close proximity to the host cell nucleus and involves the viral capsid. Here, we present the crystal structure of MxB and reveal determinants involved in HIV-1 restriction. MxB adopts an extended antiparallel dimer and dimerization, but not higher-ordered oligomerization, is critical for restriction. Although MxB is structurally similar to MxA, the orientation of individual domains differs between MxA and MxB, and their antiviral functions rely on separate determinants, indicating distinct mechanisms for virus inhibition. Additionally, MxB directly binds the HIV-1 capsid, and this interaction depends on dimerization and the N terminus of MxB as well as the assembled capsid lattice. These insights establish a framework for understanding the mechanism by which MxB restricts HIV-1.
Dynamic run-time architecture techniques for enabling continuous optimization

Future computer systems will integrate tens of multithreaded processor cores on a single chip die, resulting in hundreds of concurrent program threads sharing system resources. These designs will be the cornerstone of improving throughput in high-performance computing and server environments. However, to date, appropriate systems software (operating system, run-time system, and compiler) technologies for these emerging machines have not been adequately explored. Future processors will require sophisticated hardware monitoring units to continuously feed back resource utilization information to allow the operating system to make optimal thread co-scheduling decisions and also to software that continuously optimizes the program itselfNevertheless, in order to continually and automatically adapt systems resources to program behaviors and application needs, specific run-time information must be collected to adequately enable dynamic code optimization and operating system scheduling. Generally, run-time optimization is limited by the time required to collect profiles, the time required to perform optimization, and the inherent benefits of any optimization or decisions. Initial techniques for effectively utilizing run-time information for dynamic optimization and informed thread scheduling in future multithreaded architectures are presented
Religiosity and Political Tolerance in Poland

L'A. se propose de clarifier l'influence de la religion sur le processus democratique en Pologne post-communiste. Apres avoir passe en revue les postulats de precedentes etudes, il se fonde sur les resultats d'une enquete nationale datant de 1993 pour reviser l'idee communement admise selon laquelle l'affiliation, l'engagement et la pratique religieuses auraient une influence directe, forte et negative sur la tolerance et le liberalisme politiques. L'etude correle les variables religieuses et politiques avec des variables de controle (âge, statut socio-economique et attitude sociale liberale). Les resultats mettent en evidence que c'est davantage une attitude theocratique - i.e. pronant un engagement fort de l'Eglise dans la vie politique - plutot que l'affiliation ou la pratique religieuses en tant que telles, qui est predictive de l'intolerance politique. Neanmoins, compte-tenu que la majorite des Catholiques Polonais ne partagent pas de telles visees theocratiques, l'A. conclut que la religiosite populaire polonaise ne constitue pas un obstacle a la consolidation democratique.
Radio-frequency infrared double resonance of a PH3v2-transition

Abstract Radio-frequency transitions between Stark levels in the P(3,2) line of the PH 3 v 2 -band were measured by rf — infrared double resonance in
Decimation of triangle meshes

The polygon remains a popular graphics primitive for computer graphics application. Besides having a simple representation, computer rendering of polygons is widely supported by commercial graphics hardware and software. However, because the polygon is linear, often thousands or millions of primitives are required to capture the details of complex geometry. Models of this size are generally not practical since rendering speeds and memory requirements are proportional to the number of polygons. Consequently applications that generate large polygonal meshes often use domain-specific knowledge to reduce model size. There remain algorithms, however, where domainspecific reduction techniques are not generally available or appropriate. One algorithm that generates many polygons is marching cubes. Marching cubes is a brute force surface construction algorithm that extracts isodensity surfaces from volume data, producing from one to five triangles within voxels that contain the surface. Although originally developed for medical applications, marching cubes has found more frequent use in scientific visualization where the size of the volume data sets are much smaller than those found in medical applications. A large computational fluid dynamics volume could have a finite difference grid size of order 100 by 100 by 100, while a typical medical computed tomography or magnetic resonance scanner produces over 100 slices at a resolution of 256 by 256 or 512 by 512 pixels each. Industrial computed tomography, used for inspection and analysis, has even greater resolution, varying from 512 by 512 to 1024 by 1024 pixels. For these sampled data sets, isosurface extraction using marching cubes can produce from 500k to 2,000k triangles. Even today’s graphics workstations have trouble storing and rendering models of this size. Other sampling devices can produce large polygonal models: range cameras, digital elevation data, and satellite data. The sampling resolution of these devices is also improving, resulting in model sizes that rival those obtained from medical scanners. This paper describes an application independent algorithm that uses local operations on geometry and topology to reduce the number of triangles in a triangle mesh. Although our implementation is for the triangle mesh, it can be directly applied to the more general polygon mesh. After describing other work related to model creation from sampled data, we describe the triangle decimation process and its implementation. Results from two different geometric modeling applications illustrate the strengths of the algorithm.
An application of passive samplers to understand atmospheric mercury concentration and dry deposition spatial distributions

Two modified passive samplers were evaluated at multiple field locations. The sampling rate (SR) of the modified polyurethane foam (PUF)-disk passive sampler for total gaseous mercury (TGM) using gold-coated quartz fiber filters (GcQFF) and gaseous oxidized mercury (GOM) using ion-exchange membranes (IEM) were 6.4 ± 1.4 and 15.3 ± 0.3 m3 day−1, respectively. The relative percent difference between TGM and GOM concentrations measured by a Tekran system and the passive samplers averaged 19 ± 14 and 13 ± 12% and ranged between 4–44 and 1.5–41%, respectively. The GcQFF and IEM substrates were also evaluated as collection media for surrogate surface dry deposition measurements. Mercury (Hg) concentration and dry deposition gradients were observed using these samplers at an urban/industrial site and compared to a rural/remote site. The Hg dry deposition rates measured by the surrogate surfaces were always higher than those calculated by a widely used inferential modeling method (1.3–50 fold). The Hg dry deposition measured at urban and suburban sites were comparable to those calculated from model. However, they were very different at a rural site, probably due to the low concentrations. Both methods are relatively low cost and will aid in understanding spatial distributions of Hg ambient air concentrations and dry deposition.
Phenobarbital and organic solvent toxicity.

The effect of phenobairbital pretreatment on the toxicity of a variety of halogenated hydrocarbon solvents has been investigated in the rat. The present data demonstrate the marked potentiation of toxicity of carbon tetrachloride and chloroform by phenobarbital pretreatment. However, a potentiating effect of phenobarbital on the toxicity of other halogenated solvents, including methylene chloride, methyl chloroform, trfchloroeithylene, and perchloroethylene could not be demonstrated by utilizing single high-dose levels of these solvents. Since barbiturates may have considerable usage among industrial workers, it is important to be aware of the potential for synergistic action that may be associated with the inhalation of several of the halogenated solvents as well as the apparent lack of potentiation associated with others.
Validation of an acculturation measure for Hispanic adolescents.

Based on the continuing growth and youthfulness of the Hispanic population in the United States, valid cultural measures are needed for Hispanic adolescents. Hispanics living in this country experience acculturation or cultural change during their exposure to American culture. A matched sample of 994 Hispanic students and their parents completed acculturation measures. Scores on a 10-item acculturation scale completed by the adolescents' parents correlated significantly .49 with a single-item rating, a measure of acculturation by adolescents. This finding supports construct validity for a measure of language use as an index of linguistic acculturation for Hispanic adolescents.
Open-ocean transport of particulate trace metals by bubbles

Abstract An adsorptive bubble separation technique was used to show that a substantial fraction of particulate trace metals in open ocean surface water samples could be adsorbed transported by bubbles to the sea-air interface. Rates of transport by bubbles were estimated for Sargasso Sea surface waters and were of the same order of magnitude as atmospheric fluxes to the sea surface. Large particles formed readily in the froth. The bubble transport flux was in remarkable agreement with an independently estimated flux of particulate trace metals to deep waters associated with sinking organic matter. Bubble-induced aggregation may accelerate the removal of particulate trace metals from the mixed layer.
Methodological issues in studies of imitation: Comments on McKenzie & Over and Koepke et al.*

This paper examines two studies that fail to find evidence for neonatal imitation. The studies are flawed in ways that would serve to obscure genuine imitation effects. These flaws include: (a) inappropriate stimuli, (b) inadequate videotaping techniques, and (c) insensitive scoring and analysis procedures. We suggest ways the authors could have increased the sensitivity of their studies, and highlight interesting trends in the authors' own data that they prematurely discount.
Searcher response in a hypertext-based bibliographic information retrieval system

This article examines searcher behavior and affective response to a hypertext-based bibliographic information retrieval system called HyperLynx for searchers with different search skills and backgrounds. Search times and number of nodes visited were recorded for five specified search queries, and views of the system were recorded for each searcher. No significant differences were found in search times our user satisfaction with the system, indicating that a hypertext-based approach to bibliographic retrieval could be approapriate for a variety of searcher experience levels. © 1995 John Wiley & Sons, Inc.
Effect of intestinal motility on the absorption of sodium in man.

HE PURI'OS~ of the /)resent report is to review the results of experiments performed to determine the normal quantitative characteristics of sodium transport from the intestinal tract of man, and to assess the significance of intraluminal pressure fluctuations as they relate to absorption. Sodium was chosen as a test material for this combined absorption and motility study because: (1) its exact rate of absorption can be quantified, and (2) it is absorbed rapidly from the small intestine and, therefore, permits accurate correlation with recordings of intraluminal pressure during a short-term experiment.
A New Model for Free-Stream Turbulence Effects on Boundary Layers

A model has been developed to incorporate more of the physics offree-stream turbulence effects into boundary layer calculations. The transport in the boundary layer is modeled using three terms: (1) the molecular viscosity, ν (2) the turbulent eddy viscosity, ∈ T , as used in existing turbulence models; and (3) a new free-stream-induced eddy viscosity, ∈ f . The three terms are added to give an effective total viscosity. The free-stream-induced viscosity is modeled algebraically with guidance from experimental data. It scales on the rms fluctuating velocity in the free stream, the distance from the wall, and the boundary layer thickness. The model assumes a direct tie between boundary layer and free-stream fluctuations, and a distinctly different mechanism than the diffusion of turbulence from the free-stream to the boundary layer assumed in existing higher order turbulence models. The new model can be used in combination with any existing turbulence model. It is tested here in conjunction with a simple mixing length model and a parabolic boundary layer solver. Comparisons to experimental data are presented for flows with free-stream turbulence intensities ranging from I to 8 percent and for both zero and nonzero streamwise pressure gradient cases. Comparisons are good. Enhanced heat transfer in higher turbulence cases is correctly predicted. The effect of the free-stream turbulence on mean velocity and temperature profiles is also well predicted. In turbulent flow, the log region in the inner part of the boundary layer is preserved, while the wake is suppressed. The new model provides a simple and effective improvement for boundary layer prediction.
C6 pyridinium ceramide influences alternative pre-mRNA splicing by inhibiting protein phosphatase-1

Alternative pre-mRNA processing is a central element of eukaryotic gene regulation. The cell frequently alters the use of alternative exons in response to physiological stimuli. Ceramides are lipid-signaling molecules composed of sphingosine and a fatty acid. Previously, water-insoluble ceramides were shown to change alternative splicing and decrease SR-protein phosphorylation by activating protein phosphatase-1 (PP1). To gain further mechanistical insight into ceramide-mediated alternative splicing, we analyzed the effect of C6 pyridinium ceramide (PyrCer) on alternative splice site selection. PyrCer is a water-soluble ceramide analog that is under investigation as a cancer drug. We found that PyrCer binds to the PP1 catalytic subunit and inhibits the dephosphorylation of several splicing regulatory proteins containing the evolutionarily conserved RVxF PP1-binding motif (including PSF/SFPQ, Tra2-beta1 and SF2/ASF). In contrast to natural ceramides, PyrCer promotes phosphorylation of splicing factors. Exons that are regulated by PyrCer have in common suboptimal splice sites, are unusually short and share two 4-nt motifs, GAAR and CAAG. They are dependent on PSF/SFPQ, whose phosphorylation is regulated by PyrCer. Our results indicate that lipids can influence pre-mRNA processing by regulating the phosphorylation status of specific regulatory factors, which is mediated by protein phosphatase activity.
The cognitive viewpoint in information science

The meaning of the cognitive view of information science is briefly summarized, and representative works which propose or use this viewpoint are reviewed. It is shown, by example, that considering problems of information science from this point of view has led to significant advances in a variety of areas of information science, including bibliometrics, user studies, the reference interview and information retrieval. This variety of applications suggests that the cognitive viewpoint may be a powerful framework for the general theoretical and practical development of information science.
Hopping conductivity in one dimension with asymmetric transfer rates.

The frequency-dependent conductivity is calculated for a one-dimensional disordered system in the presence of an external biased electric field. Four classes of transfer-rate distributions are discussed. The singular distribution for which the inverse first moment does not exist gives the most interesting nonanalytic behavior. For the class-(a) distribution such that all inverse moments exist, numerical results are in complete agreement with the analytic expansions for weak disorder, as discussed in our previous work. For the class-(c) distribution such that no inverse moments exist, one finds nonuniversal crossover behavior as well as nonanalytic frequency dependence of the ac conductivity. We find a crossover region ${\ensuremath{\omega}}_{1}$\ensuremath{\le}\ensuremath{\omega}\ensuremath{\le}${\ensuremath{\omega}}_{2}$ such that for \ensuremath{\omega}${\ensuremath{\omega}}_{1}$, the conductivity \ensuremath{\sigma}\ensuremath{\sim}${\ensuremath{\omega}}^{\ensuremath{\alpha}}$ (0\ensuremath{\alpha}1), and for \ensuremath{\omega}g${\ensuremath{\omega}}_{2}$, \ensuremath{\sigma}\ensuremath{\sim}${\ensuremath{\omega}}^{\ensuremath{\alpha}/(2\mathrm{\ensuremath{-}}\ensuremath{\alpha})}$ with behavior the same as for the unbiased case. For the class-(b') distribution such that only one inverse moment exists, nonanalytic leading corrections in the conductivity are also obtained. Finally, for the bond-percolation model, we find no crossover behavior in the frequency-dependent conductivity even in the strong biased case.
Travel vaccination for rabies.

Rabies is a widely distributed zoonotic disease of major public-health importance. While canine rabies has been controlled throughout most of the developed world, it remains a significant burden in developing countries, particularly in Africa and Asia. Owing to the effectiveness of local rabies control in industrialized countries, the lack of familiarity with rabies may place certain travelers to countries with a higher prevalence of rabies at higher risk for potential contact with rabid animals, requiring rabies postexposure prophylaxis. Where necessary, some travelers may need to consider rabies pre-exposure vaccination, depending on planned activities and duration of travel within a given country. Education regarding behavior around unfamiliar animals and general familiarity with local rabies epidemiology is often sufficient to reduce a person’s risk of exposure. Travelers to countries where rabies is prevalent should balance the cost and inconvenience of immunization to the benefits of rabies pre-expo...
Promotion of Malignant Astrocytoma Cell Migration by Osteopontin Expressed in the Normal Brain Differences in Integrin Signaling during Cell Adhesion to Osteopontin Versus Vitronectin

The extracellular matrix of the normal adult brain lacks expression of most of the adhesive glycoproteins that are known to promote cell attachment, and it has been thought that the malignant invasion of astrocytoma tumor is mediated primarily by remodeling of the matrix by the tumor cells. It has been reported, however, that normal brain neuropil does contain a protein(s) that promotes cell attachment. Therefore, we explored the possibility that the cell attachment protein, osteopontin, is expressed in the normal human brain. Here, we report that osteopontin is expressed in the cortical gray and white matter of normal adult brain, with the levels of osteopontin expression being equivalent to those in malignant astrocytic tumor biopsies as assessed by Western blot analysis. Immunoblotting identified osteopontin polypeptides with relative molecular weights of 60- and 65-kDa in normal brain white matter and in astrocytic tumors, with an additional 70-kDa polypeptide being identified in normal cortical gray matter and in some astrocytic tumors. Recombinant osteopontin was found to promote attachment of U-251MG human malignant astrocytoma cells in a process that was inhibited by anti-integrin monoclonal antibodies anti-αvβ3 (75%), anti-αvβ5 (80%), and anti-α5 (40%). On attachment, integrins αvβ5 and αvβ3 localized to focal adhesions, and there was an alteration in cell morphology with the formation of lamellae-like processes. The attachment was associated with activation of Rac in a slow and prolonged fashion and rapid activation of Rho. Similarly, integrins αvβ5 and αvβ3 localized to focal adhesions on attachment of the U-251MG cells to vitronectin, but on this substrate, the cells assumed a spread and flat morphology, and there was rapid activation of both Rac and Rho. Extracts of normal brain white matter were capable of promoting haptotactic migration, and this response was inhibitable by monoclonal antibodies anti-αvβ3 and anti-α5. Depletion of the osteopontin in these extracts abrogated the haptotactic response significantly (50%). These data indicate that the cell attachment protein, osteopontin, is expressed in the normal adult brain and that it has the potential to promote malignant astrocytoma cell invasion.
Remote sensing of biotic effects: Zebra mussels (Dreissena polymorpha) influence on water clarity in Saginaw Bay, Lake Huron

In this study, Advanced Very High Resolution Radiometer (AVHRR) remote sensing reflectance ( Rrs), imagery from 1987‐1993 is used to study changes in water clarity before and after zebra mussels (Dreissena polymorpha) were discovered in Saginaw Bay, Lake Huron. Spatial and temporal trends in the data indicate distinct and persistent increases in water clarity in the inner bay after the first large recruitment of zebra mussels in the fall of 1991. The pre-Dreissena imagery show that turbidity in the inner bay was influenced by the Saginaw River discharge in spring, biological production (plankton) in summer, and wind-driven resuspension in fall, with highest turbidity in spring and fall. Spatial patterns in the post- Dreissena images were more similar regardless of season, with low reflectances in the shallow regions of the inner bay where zebra mussel densities were highest. A regression model based on point data from 24 sampling stations over the 7-yr period indicates that reflectances varied significantly by site and zebra mussel densities, as well as seasonally. Trends in observed and predicted values of reflectances followed similar patterns at each station—highest values were found during 1991 and lowest during 1992 at all stations, with slightly higher Rrs in 1993 compared to 1992. Whereas AVHRR Rrs highlight the value of historical imagery for reconstructing seasonal and interannual turbidity patterns in near-shore waters, a new generation of operational ocean color satellites, such as SeaWiFS (Sea-viewing Wide Field-of-view Sensor) and the newly launched MODIS (moderate resolution imaging spectroradiometer), now provide for routine monitoring of important biological and physical processes from space.
Sensitivity and perturbation analysis of artificial feedback neural networks

Summary form only given. The authors apply the result established by A.N. Michel et al. (1992) to systems of differential inequalities. By using the differential inequalities to dominate a class of nonlinear systems, they obtain some new results on robust stability of the nonlinear systems. They show that, when applied to linear systems, these results yield robustness criteria which are considerably simpler than corresponding existing robust stability tests. However, the principal objective of the present work is to apply the above results in the study of uncertainty issues of artificial feedback neural networks, such as Hopfield neural networks. The authors attempt to provide sufficient conditions to ensure robust stability properties of equilibria of neural networks. >
An Interferon-α-Induced Tethering Mechanism Inhibits HIV-1 and Ebola Virus Particle Release but Is Counteracted by the HIV-1 Vpu Protein

Type 1 interferon (IFN) inhibits the release of HIV-1 virus particles via poorly defined mechanisms. Here, we show that IFNα induces retention of viral particles on the surface of fibroblasts, T cells, or primary lymphocytes infected with HIV-1 lacking the Vpu protein. Retained particles are tethered to cell surfaces, can be endocytosed, appear fully assembled, exhibit mature morphology, and can be detached by protease. Strikingly, expression of the HIV-1 Vpu protein attenuates the ability of human cells to adhere to, and thereby retain, nascent HIV-1 particles upon IFNα treatment. Vpu also counteracts the IFNα-induced retention of virus-like particles assembled from the Ebola virus matrix protein. Furthermore, levels of IFNα that suppress replication of Vpu-defective HIV-1 have little effect on wild-type HIV-1. Thus, we propose that HIV-1 expresses Vpu to counteract an IFNα-induced, general host defense that inhibits dissemination of enveloped virions from the surface of infected cells.
Long-term fatty acid stability in human serum cholesteryl ester, triglyceride, and phospholipid fractions.

Fatty acid profiles of biological specimens from epidemiological/clinical studies can serve as biomarkers to assess potential relationships between diet and chronic disease risk. However, data are limited regarding fatty acid stability in archived specimens following long-term storage, a variable that could affect result validity. Our objective was to determine the effect of prolonged storage at −80°C on the fatty acid profiles of serum cholesteryl ester (CE), triglyceride (TG), and phospholipid (PL) fractions. This was accomplished by determining the fatty acid profile of frozen, archived, previously unthawed serum samples from 22 subjects who participated in a controlled feeding trial. Initial analysis was performed after trial completion and the repeat analysis after 8–10 years of storage using GC. No significant differences were observed among the majority of fatty acids regardless of lipid fraction. Reliability coefficients were high for the fatty acid classes (saturated fatty acid : 0.70, MUFA : 0.90, PUFA : 0.80). When differences were identified, they were limited to low abundance fatty acids (≤1.5 mol%). These differences were quantitatively small and likely attributable to technical improvements in GC methodology rather than sample degradation. Thus, our data demonstrate that storage at −80°C up to 10 years does not significantly influence serum CE, TG, or PL fatty acid profiles.
A human epidermal differentiation-specific keratin gene is regulated by calcium but not negative modulators of differentiation in transgenic mouse keratinocytes.

Keratins Ki and K10 represent the major differentiation products of the maturing epidermal keratinocytes. Primary epidermal cell cultures from newborn Ki transgenic mice containing a 12-kilobase human Ki genomic fragment were established in order to examine the expression of both human and mouse Ki in the presence of known modulators of epidermal differentiation. Elevated levels of Ca2� in the culture medium induced both mouse Ki and human Ki. Supplementing the medium with retinoic acid or 12-0tetradecanoylphorbol- 13-acetate or introducing a Harvey viral ras oncogene (v-ras�) into the cells completely suppressed mouse Ki but not human Ki. Our results suggest that (a) the human 12-kilobase insert contains all the necessary cis-ading elements to respond to the Ca2� signal, and (b) other cis-ading elements, not present within this insert, may function independently to regulate the response of Ki to retinoids, 12-0-tetradecanoylphorbol-13-acetate, and � � --.�
Cephalic phase of acid secretion involves activation of medullary TRH receptor subtype 1 in rats

Mechanisms involved in the cephalic phase of gastric acid secretion were studied in awake fasted rats with chronic gastric fistula and exposed to the sight and smell of chow for 30 min. Acid secret...
Modeling of handoffs and performance analysis of wireless data networks

In this paper, we introduce a handoff scheme for data mobile cellular radio systems. A steady-stale traffic model is established and an analytical model of the system performance is presented. Average queue length and transmission delay are evaluated. Although mobile users holding channels move from one cell to another, there is almost no packet loss except for the negligibly small blocking probability because a channel request can be transferred from the queue of one base station to another.
Effective conversion efficiency enhancement of amorphous silicon modules by operation temperature elevation

Abstract To eliminate photo degradation, we have proposed the elevation of the operating temperature of amorphous silicon modules by thermal insulators (polystylene foam) attached to them. A solar cell which degraded 19% with ordinary accelerated test condition (AM 1.5, 1 kW/m 2 , 48°C, 550 h) degraded only 13% at 90°C. The temperature coefficient of amorphous silicon solar cell is about 2 3 of that of crystalline silicon solar cells. A simple calculation predicts about 80% of the initial efficiency in actual operation. Modules whose initial efficiency is about 9.2% were field on 1 April 1996. These modules showed more than 8% effective efficiencies on 21 August 1996. The cell temperature elevation by thermal insulation depends not on the ambient temperature but on insolation and wind speed, and is about 8°C on average and 40°C at peak. Effective conversion enhancement by temperature elevation is about 1% of the conventional one, which can be larger in later observation.
Burning of secondary forest in Amazonia: Biomass, burning efficiency and charcoal formation during land preparation for agriculture in Apiaú, Roraima, Brazil

Abstract In a burn of 5-year-old secondary forest cleared for agriculture in Roraima, Brazil, carbon partitioning was measured for above-ground portions of both secondary forest (regrowth) and the remains of original forest, felled and burned six years previously. Above-ground dry weight biomass averaged 43.0 ± 6.5 Mg (megagrams = metric tons) per hectare (Mg ha−1) for secondary forest and 105.8 ± 23.7 Mg ha−1 for original forest remains. Pre- and post-burn above-ground biomass loadings were estimated by cutting and weighing six 60-m2 plots and by line-intersect sampling (LIS) done along the axis of each post-burn plot (three transects), plus two supplementary LIS transects. High variability of initial biomass made LIS more reliable for assessing change in material >10 cm in diameter; quantities for diameter classes
Lower bounds for recognizing small cliques on CRCW PRAM'S

Abstract We show that any CRCW PRAM which recognizes k -cliques in n -node graphs in time T requires at least n Ω( K T 2 ) processors independent of its memory size. As a corollary we obtain essentially the same trade-off for unbounded fan-in circuits. We also demonstrate a similar but weaker trade-off for the memory size of CRCW PRAM's solving this problem independent of the number of processors. These bounds also answer an open question posed in [13], i.e., they show that constant-depth circuits for recognizing k -cliques in n -node graphs require size n ⊖(k) .