cssi/SciSciGPT-SciSciNet huggingface dataset:
CO2CH4 transport in polyperfluorosulfonate ionomers: Effects of polar solvents on permeation and solubility

Abstract We measured CO2 and CH4 gas permeation through polyperfluorosulfonate ionomer (PFSI) that was solvated with water, methanol, ethanol, or 1-propanol. These measurements were compared with predictions based on a two-phase, effective-media, membrane model that considered a number of possible geometries for the distributed phase (the ionic clusters). The transport parameters (solubility and diffusivity) for each of the phases and the volume fraction of dispersed phase were either measured independently or estimated from prior literature data. We were unable to match all the experimental observations with this two-phase model. We conclude that different polar solvents can incorporate themselves into the flourocarbon ‘continuous phase’ in ways that will alter the effective diffusion coefficient of that phase to gas permeation.
Factors which affect oil exchange between oil-in-water emulsion droplets stabilized by whey protein isolate: Protein concentration, droplet size and ethanol

Abstract The ability of whey protein isolate (WPI) to enhance the exchange of oil molecules between droplets in an oil-in-water emulsion was investigated. Emulsions stabilized by WPI were prepared which initially contained a mixture of 10 wt.% n-hexadecane droplets and 10 wt.% octadecane droplets. The composition of the droplets changed with time because of interdroplet oil exchange. The extent of exchange was monitored by measuring the change in the crystallization behavior of the droplets, which is related to their composition, using differential scanning calorimetry. The rate of oil exchange increased when additional protein was added to the aqueous phase of the emulsions (0–4.4 wt.%) and was proportional to the specific surface area of the droplets (0.3–2.3 m2 g−1 of emulsion). Emulsions containing no additional WPI in the aqueous phase exhibited an appreciable rate of oil exchange. We propose that oil exchange occurs because of a dynamic equilibrium between oil in the emulsion droplets and that solubilized in the aqueous phase. The non-zero rate of oil exchange in the emulsions containing low WPI concentrations may occur because of the finite solubility of hydrocarbons in water, whereas the increase in interdroplet oil exchange with increasing protein concentration is probably because the proteins bind and transfer oil molecules. The addition of ethanol (0–30 wt.%) to the aqueous phase of the emulsions dramatically increased the rate of oil exchange, most likely due to the ability of ethanol to enhance the solubility of the hydrocarbons in water.
Coherent photoproduction of vector mesons on deuterium at 5. 5 GeV

Coherent photoproduction of vector mesons ${\ensuremath{\rho}}^{0}$, $\ensuremath{\omega}$, $\ensuremath{\varphi}$, and ${\ensuremath{\rho}}^{\ensuremath{'}}$ on deuterium was studied using the SLAC 82-in. bubble chamber exposed to linearly polarized photons at 5.5 GeV. The reaction channel $\ensuremath{\gamma}d\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}d$ was studied in detail. Nine independent density-matrix parameters have been determined from the ${\ensuremath{\rho}}^{0}$ decay distribution. $\ensuremath{\rho}$ production in this channel was found to proceed almost completely through natural-parity exchange for $|t|\ensuremath{\le}0.25$ Ge${\mathrm{V}}^{2}$ and conserve $s$-channel c.m. helicity for $|t|\ensuremath{\le}0.15$ Ge${\mathrm{V}}^{2}$. A measurement of differential cross section for this channel has been made.
Secretion modification region-derived peptide disrupts HIV-1 Nef's interaction with mortalin and blocks virus and Nef exosome release

Nef is secreted from infected cells in exosomes and is found in abundance in the sera of HIV-infected individuals. Secreted exosomal Nef (exNef) induces apoptosis in uninfected CD4⁺ T cells and may be a key component of HIV pathogenesis. The exosomal pathway has been implicated in HIV-1 virus release, suggesting a possible link between these two viral processes. However, the underlying mechanisms and cellular components of exNef secretion have not been elucidated. We have previously described a Nef motif, the secretion modification region (SMR; amino acids 66 to 70), that is required for exNef secretion. In silico modeling data suggest that this motif can form a putative binding pocket. We hypothesized that the Nef SMR binds a cellular protein involved in protein trafficking and that inhibition of this interaction would abrogate exNef secretion. By using tandem mass spectrometry and coimmunoprecipitation with a novel SMR-based peptide (SMRwt) that blocks exNef secretion and HIV-1 virus release, we identified mortalin as an SMR-specific cellular protein. A second set of coimmunoprecipitation experiments with full-length Nef confirmed that mortalin interacts with Nef via Nef's SMR motif and that this interaction is disrupted by the SMRwt peptide. Overexpression and microRNA knockdown of mortalin revealed a positive correlation between exNef secretion levels and mortalin protein expression. Using antibody inhibition we demonstrated that the Nef/mortalin interaction is necessary for exNef secretion. Taken together, this work constitutes a significant step in understanding the underlying mechanism of exNef secretion, identifies a novel host-pathogen interaction, and introduces an HIV-derived peptide with antiviral properties.
The Memoirs of Ambassador Henry F. Grady: From the Great War to the Cold War

The Memoirs of Ambassador Henry F. Grady: From the Great War to the Cold War, edited by John T. McNay, Columbia: University of Missouri Press, 2009, ISBN 978-8262-1832-2, vii + 209pp. One might hav...
Coloniality and Education: Negotiating Discourses of Immigration in Schools and Communities through Border Thinking.

In this article, we examine the discursive construction of knowledge about immigration in two geographic spaces whose “border” many students navigate: a school context meant to support English Language Learners and an out-of-school faith based organization serving immigrant communities. We draw on the concept of “border thinking” (Mignolo, 2000, p. 18) to understand how colonial histories continue to influence contemporary educational contexts. Through examples from students’, community members’, and educators’ interactions with available discourses of immigration, we elaborate on the implications of community knowledge for revising school practices to represent a fuller complexity of immigration experiences.
Cytonuclear disequilibria in a spatially structured hybrid zone

A hybrid zone model was developed that uses a stepping-stone model of population structure along with both nuclear and cytoplasmic genotypes to evaluate the effect that migration has on random mating organisms when no selection is present. Numerical simulations indicate that a number of different allele frequency and cytonuclear disequilibrium patterns can be found across the hybrid zone when it has reached equilibrium, and these results are discussed in the context of relative migration rates of the two sexes and the two source populations. The importance of numbers of subpopulations sampled, census time, and the persistence of pure species individuals into the hybrid zone are also discussed. Although this model does not consider selection or assortative mating in the hybrid zone, it should provide a useful baseline for evaluating joint cytonuclear genetic data from a structurally complex hybrid zone.
Expression of type II procollagens during development of the human intervertebral disc

Mice lacking type II collagen fail to develop intervertebral discs. The present study describes
Population analyses of valence-bond wavefunctions and BeH2

Abstract A method for calculating occupation numbers and making a population analysis is proposed. The method is designed particularly for use with wavefunctions written in terms of non-orthogonal bases. An application to the valence-bond wavefunction of BeH2 is given and the results are compared with other population analysis schemes which have been proposed.
Quantification of free dihydrotestosterone in blood plasma and tissue

Abstract A gas chromatographic method has been discussed which will quantificate dihydrotestosterone by electron capture detection of the chloroacetate derivative of the steroid. The method is sensitive and specific and well suited for the determination of specific radioactivity measurement of dihydrotestosterone when biosynthesized from radioactive precursors.
Attachment of Salmonella on modified poultry skin surface.

Poultry skin was treated with formalin, trisodium phosphate, lipase, and papain before attachment. No treatment affected ultimate attachment level. Attachment using different cell suspension concentrations showed that there was a limitation in attachment level for each cell suspension concentration. Total numbers of Salmonella cells on poultry skin including cells in the surface water film were compared with numbers of irreversibly attached cells that remained after washing. At 10 7 CFU/mL inoculation, irreversibly attached cells accounted for 93% of the total surface cell population after 60 min exposure and at 10 8 level, it was 38%.
Comparison of codon usage in mycobacteriophages with and without tRNAs in their genomes

Materials and methods In this study we compared the codon frequencies between the phages that carry tRNA in their genome (Clusters A2, A3, A5, A6, A9, C1, C2, E, J, K1, L1, L2, M) to those phages without tRNA in their genome (Clusters A1, A4, B1, B2, D, F1, G) in order to determine whether the tRNAs being carried by the mycobacteriophages were needed to survive in M. smegmatis. The phages with embedded tRNAs were drawn from http:// phagesdb.org/data/. The coding sequences for the mycobacteriophages were obtained from NCBI GenBank [2]. Codon frequencies were derived for each mycobacteriophage and a BoxWhiskerChart (Figure 1) was made using a program written in Mathematica. To determine which codons may require expression of phage tRNAs, Figure 1 plot regions for phages containing tRNA (red) that show frequencies in excess of those not containing tRNA (blue) have been circled in magenta. Only a few codons meet this criteria: ACT, ATG, CAG***, CGT, GAC**, GAG*, TAC, TAT, TGG. A significant number of mycobacteriophages lay outside the non-tRNA phage boundaries for codons CAG, GAC
Measurement of the detection efficiency for 130 MeV neutrons of a cylindrical NE213 cell by the associated particle method

Abstract We have measured the detection efficiency of a 12.7 cm O × 12.7 cm cell of NE213 liquid scintillator by detecting 130 MeV neutrons in coincidence with 7 Be ions produced by the 7 Li(p, n) 7 Be reaction. Experimental considerations are described, and the data are compared to Monte Carlo calculations of the efficiency. The dependence of the detection efficiency on the light output threshold is only qualitatively reproduced, but within the nominal 10% error of such calculations.
On Nonlinear Cascades of Enstrophy over the Tropics at 200 mb during Two Northern Hemisphere Summers

Diagnostic computations of nonlinear cascades of enstrophy have been performed in the wavenumber domain for two northern summers. Attention is focused on the interactions among the waves, the interaction between the zonal flow and a given wave and the exchanges due to the beta effect. It is found that two wave ranges (low and intermediate wavenumbers) cascade enstrophy to two ranges of wavenumbers. Calculations are also performed to evaluate the contribution from the standing (92-day mean) and transient modes to the nonlinear enstrophy cascade.
Autoimmune responses against acetylcholine receptor in myasthenia gravis and their manipulation by synthetic peptides

Studies from this laboratory have mapped and synthesized the functional (i.e. acetylcholine and α-neurotoxin binding) sites as well as the sites of immune and autoimmune T- and B-cell recognition of Torpedo californica (t) and human acetylcholine receptor (AChR). Antibodies against tAChR and mouse (m) AChR α-chain peptides have been used to map the surface accessibility of the α-chain extracellular domain in soluble (i.e. free) and in membrane-bound tAChR as well as in mAChR on a live muscle cell line in culture. Myasthenia gravis is a disease caused by autoantibodies against AChR. Yet, we have found on the molecule a pathogenic T-cell epitope which does not bind anti-AChR antibodies. It has been shown, for the first time, that T cells which recognize this region of the receptor to which no autoantibodies are detectable are pathogenic because they provide help to, and activate, B cells that make antibodies against a region of the molecule known to be involved in the binding of the effector moleucule. We have also performed studies, which have been quite successful, on the manipulation of the autoimmune antibody and T cell responses by synthetic peptides. These studies should open up important avenues for the use of synthetic peptides in the manipulation and control of unwanted immune responses.
RhoA localization with caveolin-1 regulates vascular contractions to serotonin

Vascular smooth muscle contraction occurs following an initial response to an increase in intracellular calcium concentration and a sustained response following increases in the sensitivity of contractile proteins to calcium (calcium sensitization). This latter process is regulated by the rhoA/rho kinase pathway and activated by serotonin. In multiple cell types, signaling molecules compartmentalize within caveolae to regulate their activation. We hypothesized that serotonin differentially compartmentalizes rhoA within caveolar versus noncaveolar lipid rafts to regulate sustained vascular contractions. To test this hypothesis, we measured aortic contractions in response to serotonin in wild-type (WT) and cav-1-deficient mice (cav-1 KO). RhoA-dependent contractions in response to serotonin were markedly augmented in arteries from cav-1 KO mice despite a modest reduction in rhoA expression compared with WT. We found that under basal conditions, rhoA in WT arteries was primarily localized within high-density sucrose gradient fractions but temporally shifted to low-density fractions in response to serotonin. In contrast, rhoA in cav-1 KO arteries was primarily in low-density fractions and shifted to high-density fractions in a similar timeframe as that seen in WT mice. We conclude that localization of rhoA to caveolar versus noncaveolar lipid rafts differentially regulates its activation and contractions to rhoA-dependent agonists with greater activation associated with its localization to noncaveolar rafts. Disruption of rhoA localization within caveolae may contribute to increased activation and enhanced vascular contractions in cardiovascular disease.
Localized hyperthermia and X-irradiation of murine jejunum in situ: a new method.

In C3H mice, preparative surgery apposed a 15 mm length of jejunum to the peritoneal surface of the ventral abdominal wall. After the mice healed, manipulation of the abdominal wall made possible selective hyperthermic treatment and X-irradiation of the immobilized jejunal segment (US) while it remained within the peritoneal cavity and in continuity with the rest of the intestines. For hyperthermia, the ventral abdominal wall and attached US was flattened between two aluminium plates immersed in a standard water bath. The temperature at the mesenteric attachment of the US was within 0 5°C of a 44°C bath 100 s after immersion and within 0–3°C at steady-state. Xenon-133 washout studies showed that the treatment technique did not compromise blood flow to the IJS. The preparative surgery left the IJS normally responsive to X-irradiation as determined by crypt microcolony assay. Hyperthermia treatment by itself at 44°C for up to 20 min caused no loss of crypts or villi; however, adjuvant 5–15 min 44°C hyperthe...
Removal of oxygen impurity during the growth of CaF2 single crystals

Abstract Oxygen impurity from CaF2 starting material was removed, during the growth of single crystals, using CoF2 as scavenger. The efficiency of CoF2 was found to be greater, under the specified growth conditions, than that of PbF2. No significant selective absorption of the CoF2 scavenged CaF2 crystals was observed after irradiation.
Stressors, resources, and well-being among Latino and White warehouse workers in the United States.

Background Social forces and cultural factors may contribute to Latino and White workers experiencing similar jobs differently. This study examines the psychosocial stressors and resources experienced by Latino and White workers in manual material handling jobs in the US and the effects of these stressors and resources on worker well-being. Methods Fifty-nine Latino warehouse workers were matched with White workers by job title, job tenure, and warehouse facility. Matched sample t tests and linear regression analyses models were conducted. Results Results reveal similar psychosocial stressors and resources for both groups. However, Latino workers reported better well-being. For Latino workers, social resources at work such as management fairness and supervisor support have a stronger relationship with well-being. For White workers wage fairness is the most significant predictor for well-being. Conclusions These differential results challenge us to consider how cultural factors, expectations and the prior work history of Latino workers may influence their experience of work and the effect of work on health. Am. J. Ind. Med. 53:252–263, 2010. © 2009 Wiley-Liss, Inc.
U.S. Spanish-Language Television Management during the Industry’s First 50 Years

Many people were stunned to learn the Spanish-language television network Univision was the highest rated in prime time among all U.S. networks in July 2013, a feat it repeated a year later. Steady growth of its demographic and advertising bases, combined with astute management, has brought success to this dynamic industry sector. However, the boom years were preceded by several decades of formidable challenges and lean periods. This article exa mines the principal technological, programming, financial and competitive obstacles network management faced from the 1970s to the 2000s, illustrating the variety of fronts on which ethnic-oriented media leaders maneuvered during a period of rapid population growth and industry transformation.
Biopsychological markers of distress in informal caregivers.

Background.Thirty caregiving wives participated in a study of caregiving distress and negative mood (depressive symptoms) by making diary entries on stressful caregiving situations and collecting s...
Solid-state fluorescence lifetime measurements

The intrinsic fluorescence properties of molecules in condensed phases are complicated by intermolecular interactions. In crystalline solids the fluorescence depends on the photophysics of individual molecules as well as the interactions between molecules in the solid state Even a chemically pure crystal has some lattice disorder, which alters the local environment and changes the intermolecular interactions. Sample preparation and experimental technique may influence the fluorescence results.
Human Cytomegalovirus-Mediated Enhancement of Human Immunodeficiency Virus Type-1 Production in Monocyte-Derived Macrophages

Monocyte-derived macrophages were co-infected with human immunodeficiency virus (HIV), strain HIVBa-L, and human cytomegalovirus (HCMV) strain AD 169. HCMV enhanced the production of p24 antigen and infectious HIV, but HIV had no effect on HCMV production. In dually infected cultures HIV p24 antigen levels were increased 5- to 15-fold during the first 3 weeks of culture. This enhancement was observed both for cell-associated and extracellular p24 antigen from co-infected cells. The replication of macrophage-tropic clinical isolates of HIV were also enhanced by HCMV, but HCMV did not enable T cell-tropic viruses to replicate in macrophages. Conversely, HCMV clinical isolates from blood or urine were able to upregulate HIV production. Similar enhancement of HIV p24 antigen levels was observed with noninfectious, heat-inactivated HCMV, indicating that replication of HCMV in the macrophages was not necessary. Although replication was not required, the enhancing ability of HCMV was associated with the virus. Enhancement of HIV segregated with the HCMV pelleted virus particles and not the supernatant in stock virus. The fact that HCMV and HIV are detected in macrophages in persons with HIV infection highlights the importance of this system for studying interactions between HIV and HCMV in persons with HIV infection.
Flavor stability and quality of high-oleate and regular soybean oil blends during frying

The percentages of oleate (18∶1), linoleate (18∶2), and linolenate (18∶3) in blended soybean oils (SBO) were evaluated for their impact on flavor stability and quality in fried foods. Six SBO treatments, including a control (conventional SBO, 21.5% 18∶1) and a high-18∶1 SBO (HO, 79% 18∶1), were tested. In addition, these two oils were mixed in different ratios to make three blended oils containing 36.9, 50.7, and 64.7% 18∶1, abbreviated as 37%OA, 51%OA, and 65%OA, respectively. Also, a low-18∶3 (LL) SBO containing 1.4% 18∶3 and 25.3% 18∶1 was tested. Bread cubes (8.19 cm3) were fried in each of 18 oils (6 treatments ×3 replicates). The fresh and stored bread cubes fried in 79%OA were second to the cubes fried in LL in overall flavor quality, were the weakest in intensity of stale, grassy, fishy, cardboard, and burnt flavors by sensory evaluation, and contained the least amounts of hexanal, hexanal, t-2-heptenal, t,t-2,4-nonadienal, and t,t-2,4-decadienal in volatile analysis. Other treatments were intermediate in these sensory and instrumental evaluations, as related to their 18∶1, 18∶2, and 18∶3 concentrations. In general, the results suggested that the overall flavor stability and eating quality of foods fried in the six oil treatments from the best to the poorest would be: LL≥79%OA, 65%OA, 51%OA, 37%OA, and control.
Three-dimensional structure of the transmembrane domain of Vpu from HIV-1 in aligned phospholipid bicelles

The three-dimensional backbone structure of the transmembrane domain of Vpu from HIV-1 was determined by solid-state NMR spectroscopy in two magnetically-aligned phospholipid bilayer environments (bicelles) that differed in their hydrophobic thickness. Isotopically labeled samples of Vpu(2-30+), a 36-residue polypeptide containing residues 2-30 from the N-terminus of Vpu, were incorporated into large (q = 3.2 or 3.0) phospholipid bicelles composed of long-chain ether-linked lipids (14-O-PC or 16-O-PC) and short-chain lipids (6-O-PC). The protein-containing bicelles are aligned in the static magnetic field of the NMR spectrometer. Wheel-like patterns of resonances characteristic of tilted transmembrane helices were observed in two-dimensional (1)H/(15)N PISEMA spectra of uniformly (15)N-labeled Vpu(2-30+) obtained on bicelle samples with their bilayer normals aligned perpendicular or parallel to the direction of the magnetic field. The NMR experiments were performed at a (1)H resonance frequency of 900 MHz, and this resulted in improved data compared to lower-resonance frequencies. Analysis of the polarity-index slant-angle wheels and dipolar waves demonstrates the presence of a transmembrane alpha-helix spanning residues 8-25 in both 14-O-PC and 16-O-PC bicelles, which is consistent with results obtained previously in micelles by solution NMR and mechanically aligned lipid bilayers by solid-state NMR. The three-dimensional backbone structures were obtained by structural fitting to the orientation-dependent (15)N chemical shift and (1)H-(15)N dipolar coupling frequencies. Tilt angles of 30 degrees and 21 degrees are observed in 14-O-PC and 16-O-PC bicelles, respectively, which are consistent with the values previously determined for the same polypeptide in mechanically-aligned DMPC and DOPC bilayers. The difference in tilt angle in C14 and C16 bilayer environments is also consistent with previous results indicating that the transmembrane helix of Vpu responds to hydrophobic mismatch by changing its tilt angle. The kink found in the middle of the helix in the longer-chain C18 bilayers aligned on glass plates was not found in either of these shorter-chain (C14 or C16) bilayers.
Lipid Based Nanotubes as Functional Architectures with Embedded Fluorescence and Recognition Capabilities

A limited combinatorial strategy was used to synthesize a small library of soft lipid-based materials ranging from structurally unordered fibers to highly uniform nanotubes. The latter nanotubes are comprised of a bilayer structure with interdigitated alkyl chains associated through hydrophobic interactions. These tubes contain accessible 2,6-diaminopyridine linkers that can interact with thymidine and related nucleosides through multipoint hydrogen bonding, thereby quenching the intrinsic fluorescence of the aromatic linker. These results are the first example of a systematic strategy to design functional lipid nanotubes with precise structural and functional features.
"Bristly" Cristae in Algal Mitochondria

In forming zoospores of Oedogonium, mitochondria were found to contain numerous, evenly-spaced bristle-like structures projecting from the surface of cristae.
Central auditory neurophysiology of a sound-producing fish: the mesencephalon of Pollimyrus isidori (Mormyridae)

This paper describes the auditory neurophysiology of the mesencephalon of P. isidori, a soundproducing mormyrid fish. Mormyrids have a specialized pressure-sensitive auditory periphery, and anatomical studies indicate that acoustic information is relayed to the mesencephalic nucleus MD. Fish were stimulated with tone bursts and clicks, and responses of MD neurons were recorded extracellularly. Auditory neurons had best frequencies (BF) and best sensitivities (BS) that fell within the range of frequencies and levels of the natural communication sounds of these fish. BSs were in the range of 0 to — 35 dB (re. 1.0 dyne/cm2). Many of the neurons were tuned (Q10 dB: 2–6), and had BFs in the range of 100–300 Hz where the animal's sounds have their peak energy. A range of different physiological cell types were encountered, including phasic, sustained, and complex neurons. Some of the sustained neurons showed strong phase-locking to tones. Many neurons exhibited non-monotonic rate-level functions. Frequencies flanking the BF often caused a reduction in spontaneous activity suggesting inhibition. Many neurons showed excellent representation of click-trains, and some showed a temporal representation of inter-click-intervals with errors less than 1 ms.
Asymmetrical distribution of microvilli in cytochalasin B-induced pseudocleavage of mouse oocytes

CYTOCHALASIN B, a fungal alkaloid first described by Carter1, has diverse effects on cultured cells, including inhibition of morphogenetic and movement processes, and interference with hormone mediated cellular response2. It also induces various cultured mammalian cells to segregate the nucleus into an evagination of the plasma membrane which occasionally breaks away from the cell body3. Although some of the biological effects of cytochalasin B have been attributed to the disruption of microfilamentous structures found in cells, the mechanism of action of the drug remains unclear4. We have found that mouse oocytes cultured in the presence of cytochalasin B divide into two compartments; a process we called ‘pseudocleavage’5. We now report, using scanning electron microscopy, that although one of the oocyte compartments is covered with microvilli, the other is smooth. This suggests that cytochalasin B triggers a redistribution of cell surface elements in the mouse oocyte.
Hydrogen and fresh water production from sea water

Abstract A review of hydrogen production as a source of energy was made. Electrolysis was found to be the major technique of hydrogen production from sea water. A potential difficulty with this process is the chlorine and oxygen that are evolved at the anode. A new concept for hydrogen production from sea water by an electrochemical method was investigated. In this concept fresh water and hydrogen are produced simultaneously. The electric cell consists of a set of electrodes with each electrode suspended between two plastic membranes (cations and anions). Hydrogen is evolved from the cation compartment and chlorine gas from the anion compartment. Cost estimation and evaluation of the process were made.
K − p Interactions at 1.15 BeV/ c

This paper contains the conclusion of the systematic study of ${K}^{\ensuremath{-}}p$ interactions in the Lawrence Radiation Laboratory's 15-in. hydrogen bubble chamber at 1.15 BeV/c. In particular, we report on the elastic and charge-exchange scattering, ${K}^{*}N$ production, and $\ensuremath{\Sigma}\ensuremath{\pi}$ reactions. The procedure used in scanning, measuring, and computer analysis is described in detail. The similarity of total as well as differential cross sections for the three $\ensuremath{\Sigma}\ensuremath{\pi}$ charge states suggests predominant production from the $T=0$ state for this channel. The angular distributions for the $\ensuremath{\Sigma}\ensuremath{\pi}$ reactions, as well as the elastic and charge-exchange scattering, indicate that partial waves as high as ${F}_{\frac{5}{2}}$ must be involved. The analysis of the ${K}^{\ensuremath{-}}p{\ensuremath{\pi}}^{0}$ reactions substantiates the earlier preliminary result of isotopic spin \textonehalf{} for the ${K}^{*}$ resonance. The angular distributions and correlations in the ${K}^{\ensuremath{-}}p{\ensuremath{\pi}}^{0}$ and ${K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}n$ reactions support the conclusion, derived from the previous study of our ${\overline{K}}^{0}p{\ensuremath{\pi}}^{\ensuremath{-}}$ events, that the ${K}^{*}$ spin is 0 or 1. A summary of cross sections for all the reactions studied in the experiment is given.
Role of GSK3 Signaling in Neuronal Morphogenesis

Glycogen synthase kinase 3 (GSK3) is emerging as a key regulator of several aspects of neuronal morphogenesis including neuronal polarization, axon growth and axon branching. Multiple signaling pathways have been identified that control neuronal polarization, including PI3K, Rho-GTPases, Par3/6, TSC-mTOR, and PKA-LKB1. However, how these pathways are coordinated is not clear. As GSK3 signaling exhibits crosstalk with each of these pathways it has the potential to integrate these polarity signals in the control neuronal polarization. After neurons establish polarity, GSK3 acts as an important signaling mediator in the regulation of axon extension and axon branching by transducing upstream signaling to reorganizion of the axonal cytoskeleton, especially microtubules. Here we review the roles of GSK3 signaling in neuronal morphogenesis and discuss the underlying molecular mechanisms.
Antigenic variation in trypanosomes: secrets surface slowly.

Among pathogenic micro-organisms that evade the mammalian immune responses, Trypanosoma brucei has developed the most elaborate capacity for antigenic variation. Trypanosomes branched early during eukaryotic evolution. They are characterized by many aberrations, ranging from the unusual compartmentation of metabolic pathways to the heresy of RNA editing. The ubiquitous phenomenon of glycosylphosphatidylinositol-anchoring of eukaryotic plasma membrane proteins and RNA trans-splicing (trypanosome genes contain no introns), which adds an identical leader sequence to all trypanosome mRNAs, were first defined during studies of antigenic variation. Genetic transformation of trypanosomes and the high efficiency of gene targeting provide new opportunities to investigate the regulation of antigenic variation. There is every reason to expect trypanosomes to provide further surprises and insights into the evolution of genetic regulatory mechanisms.
Greenhouse effect, sea level rise, and coastal zone management

Abstract Increasing concentrations of carbon dioxide and other gases are expected to warm the earth several degrees in the next century by a mechanism known as the greenhouse effect. Such a warming could cause sea level to rise two to five feet by expanding ocean water, melting mountain glaciers, and perhaps eventually causing polar glaciers to melt and slide into the oceans. A rise in sea level of even three feet could cause substantial erosion of beaches and coastal wetlands, increased flooding, and intrusion of saltwater into rivers, bays, and aquifers. Fortunately, many of the adverse consequences can be avoided by taking timely measures in anticipation of sea level rise. Nevertheless, many coastal zone managers are reluctant to take these measures until the prospect of sea level rise becomes more certain. This article examines the implications of future sea level rise and identifies anticipatory measures that may be appropriate today in spite of current uncertainties.
Implications of mortality and morbidity for health care delivery in Ghana

The lack of adequate statistics makes it almost impossible to get an accurate picture of the health situation in developing countries. Based on the fragmentary data available this paper examines the determinants and consequences of "unnecessary" deaths and ill health in Ghana. Even though the main causes of death among the majority of the people are preventable the health care delivery system emphasizes curative rather than preventive medicine and urban-based instead of rural-based practices. Despite the very heavy investment in health there has been little or no impact on the health status of the population particularly of the 70% of the people who live in rural areas. In addition to these 2 basic structural problems rural Ghanian society adopts a traditional family-oriented approach to illness which often does not include the utilization of modern health services. Economic factors--such as income health insurance coverage the cost of health services and the availability of free medical care--strongly influence utilization. Persistent high levels of morbidity and mortality especially in rural areas suggest the need for an emphasis on preventive rather than curative measures and for community-based rather hospital-based health care. The 2 Ghanaian rural health projects that have experimentally involved village health workers--the Danfa and the Brong Ahafo projects--have had some success in involving communities in health care and training village health workers. Primary health care is a real challenge to the current government.
Preparation, crystallization and preliminary X-ray analysis of a complex between the Plasmodium vivax sexual stage 25 kDa protein Pvs25 and a malaria transmission-blocking antibody Fab fragment.

The Plasmodium vivax sexual stage 25 kDa protein Pvs25, located on the surface of the ookinete form of the parasite, is a vaccine candidate designed to elicit immunity that blocks the transmission of malaria by mosquitoes. The 2A8 murine monoclonal antibody directed against recombinant Pvs25 prevents the formation of P. vivax oocysts in mosquitoes fed in the laboratory. The complex between recombinant Pvs25 and the Fab fragment of 2A8 forms crystals that diffract X-rays to 3.5 A. Two native data sets, A and B, have been collected from crystals of the Pvs25–Fab complex. Both crystals belong to space group P21, with unit-cell parameters of a = 86.3, b = 61.7, c = 142.7 A, β = 101.7° for data set A and a = 86.8, b = 61.0, c = 149.3 A, β = 104.3° for data set B, and contain two complex molecules per asymmetric unit. Efforts are under way to reveal the structure of the Pvs25–Fab complex by molecular replacement. The three-dimensional structure of the Pvs25–Fab complex will provide an understanding of the interaction between Pvs25 and the 2A8 antibody that inhibits ookinete development in the mosquito and should aid in the development of transmission-blocking vaccines against P. vivax malaria.
Relaxation of photoexcited electron-hole plasma in quantum wells

Cette etude est limitee aux concentrations importantes en porteurs de charge et aux excitations laser inferieures a la picoseconde. Le modele inclut les phonons chauds et les echanges d'energie entre electrons et trous, par une interaction coulombienne. Le refroidissement des porteurs de charge est assez insensible aux variations d'epaisseur du puits si la densite de la feuille est maintenue constante
Geometry enrichment for mathematically gifted students

A special summer course for mathematically gifted eighth graders is described. Results of a pretest indicated that students had mastered basic geometric terms but not axiomatic approaches. A problem‐centered approach was used to develop abilities to hypothesize and carry out informai deductive proofs. Students responded well to challenging problems and worked best independently rather than in groups. Students tended to be impulsive thinkers but were able to reflect and develop more genera) results when required to do so. Geometry provides an excellent context for developing intuition, reflective thinking, and deductive reasoning abilities.
3,4-Dehydroproline, a proline antagonist

dl-3,4-Dehydroproline inhibits the growth of Lactobacillus arabinosus, Streptococcus lactis, Pediococcus cerevisiae, Leuconostoc dextranicum, and Escherichia coli, and the toxicities are competitively reversed by l-proline with inhibition indices of 3, 3, 3, 10, and 10, respectively. A noncompetitive reversal of dehydroproline toxicity by a peptide, glycylproline, is observed with E. coli, but for S. lactis, P. cerevisiae, and L. arabinosus a competitive reversal of the inhibitory effect of the analog is observed with glycylproline. Proline peptides are either more or less active than the free amino acid depending upon the assay organism. A synergistic rather than an additive effect of glycylproline in combination with proline in reversing the toxicity of dehydroproline for L. arabinosus is observed.
Gender Inequality in the Home: The Role of Relative Income, Support for Traditional Gender Roles, and Perceived Entitlement

Drawing on relative resources and gender construction theories, we examined economic and psychological factors that affect married parents’ domestic labor. Married parents from the United States (N = 801) reported whether they earned less, equal, or more income than their spouses, as well as the proportion of housework and childcare they performed. In line with a relative resources perspective, participants reported doing less domestic labor as their relative income increased. Yet, in line with gender construction theories, women reported doing more domestic labor than their spouses, regardless of their relative income. Moreover, support for traditional gender roles mediated the effect of income on domestic labor for women, but not men. In contrast, perceived domestic entitlement (feeling justified doing less domestic labor than one’s spouse) mediated the effect of income on domestic labor for men, but not women. The implications for the future of gender equality are discussed.
Vitamin D Receptor (VDR) and Group-Specific Component (GC, Vitamin D–Binding Protein) Polymorphisms in Myopia

Purpose. Epidemiologic evidence indicates that time outdoors reduces the risk of myopia, suggesting a possible role for vitamin D. This case–control study was conducted to determine whether single-nucleotide polymorphisms (SNPs) within VDR at 12q13.11 and GC at 4q12-13 are associated with myopia.
Carbon fiber reinforced cement composites improved by using chemical agents

Abstract By using short pitch-based carbon fibers (0.5% by weight of cement, 0.28 vol.% of cement mortar, or 4.5 Kg fibers/m 3 cement mortar), together with a water reducing agent and an accelerating admixture, the compressive, tensile and flexural strengths of the carbon fiber reinforced cement mortar were found to increase by about 18–31%, 113–164% and 89–112%, respectively, compared to the corresponding plain cement values. The ductility was also much improved. In addition, the electrical resistivity decreased to 0.1% of the plain cement value. The optimum fiber length was 3.0 – 5.1 mm. By arranging unidirectional continuous carbon fibers (0.25% by weight of cement or 0.13 vol.% of cement mortar) near one side of a cement specimen, together with the use of a water reducing agent and an accelerating admixture, the flexural strength of the specimen increased by 170% compared to the plain cement value.
Dressing procedure for some homoclinic connections of the Manakov system

The dressing procedure is used to obtain explicit expressions for homoclinic connections of unstable plane waves of the Manakov system of coupled nonlinear Schrodinger equations.
Behavioral and Emotional Problems in Young People with Pervasive Developmental Disorders: Relative Prevalence, Effects of Subject Characteristics, and Empirical Classification

Parents or teachers rated 487 non-clinically referred young people with Pervasive Developmental Disorders on the Nisonger Child Behavior Rating Form. The objectives of the study were to examine the relative prevalence of specific behavior problems, assess the impact of subject characteristics, and derive an empirical classification of behavioral and emotional problems for this population. Results indicated that the youngsters experienced high rates of behavior and emotional problems. Cluster analysis suggested that six- and eight-cluster solutions best fit the ratings provided by parents and teachers, respectively. Both parent and teacher cluster solutions contained groups of children characterized as problem free, well adapted, hyperactive, anxious, and with undifferentiated behavior disturbances. The empirically derived clusters were supported by data external to the analyses.
Hyperactive and aggressive behaviors in childhood: intertwined dimensions.

The relationship between aggression and hyperactivity is unclear in childhood hyperkinesis. To examine the relationship between the two dimensions, a sample of 109 first-, second-, and third grade children who were rated as hyperactive were evaluated daily by their teachers for 12 consecutive school days on the Daily Behavior Checklist. Daily recordings were made on a total of 22 specific behaviors, 11 physically or verbally aggressive acts, and 11 acts of a restless or hyperactive nature. The Conners hyperactivity score correlated. 47 with daily aggression and .49 with daily hyperactivity. A subgroup of hyperactive children who exhibited both hyperactive and aggressive behaviors at rates greater than 98% of their classmates was selected. These children were rated significantly higher on the Conners scale than an alternate subgroup of hyperactive children who showed high rates of hyperactive but not aggressive behaviors. In view of heavy reliance on teacher ratings with the Conners scale in studies of hyperactivity, careful consideration of the potential confounding of hyperactivity and aggression is recommended. Implications for classification, longitudinal investigation, and evaluation of treatment of hyperactive children were discussed.
On the inequality of Qo and ToSo with respect to solid state organic substances of biological importance

Abstract The conventional method of determining the quantity of thermal energy that must be absorbed by a substance for it to exist at the standard temperature, To (=298.15 K), is to multiply the standard entropy, So of that substance, by To. The standard entropy is determined by calculating the area under a curve comprising incremental Cp values plotted against ln T, where the lower limit is T≈10 K and the upper limit of T=To. Extrapolation of the curve to 0 K usually is achieved using the Debye T3 equation. The total quantity of heat, Qo, that must be introduced into a sample in a low temperature calorimeter to raise it from 0 K to To can be determined by calculating the area under a curve comprising the same incremental Cp values plotted against T. Conventionally, ToSo=Qo. However, in this paper it is demonstrated that for solid state organic substances ToSo≈2Qo.
Marrow adipose tissue: Response to erythropoiesis

A group of rabbits was treated chronically with phenylhydrazine to induce hemolysis and stimulate erythropoiesis. The mean volume of the marrow fat cell of a control group of hematologically normal rabbits was 54.8 pl; the mean volume of the perinephric fat cell was 549.5 pl, a volume ratio, perinephric/marrow of 10: 1. In the experimental animals the mean volume of the marrow fat cell fell to 25.9 pl; the volume of the perinephric fat cell was unchanged and the volume ratio, perinephric/marrow was 18: 1. Fat cell volume studies performed on rabbits subjected to chronic bleeding yielded comparable data. The l-C14 palmitate uptake (esterification capacity) calculated on a cell basis was the same for both marrow and perinephric fat cells and was unaffected by phenylhydrazine treatment. The fatty acid composition shows higher content of unsaturated fatty acids in the marrow fat than in the perinephric fat of the control animal. In the experimental animal there appears to be a preferential release of the unsaturated fatty acid. The findings of the study suggest that increased hematopoiesis stimulates lipolysis of marrow fat cells, probably through the local release of a chemical substance. Marrow fat appears to be functionally related to hematopoiesis rather than to systemic fat storage. Marrow fat may be involved in the metabolic support of hematopoiesis.
CaV1 and CaV2 Channels Engage Distinct Modes of Ca2+ Signaling to Control CREB-dependent Gene Expression

Summary Activity-dependent gene expression triggered by Ca 2+ entry into neurons is critical for learning and memory, but whether specific sources of Ca 2+ act distinctly or merely supply Ca 2+ to a common pool remains uncertain. Here, we report that both signaling modes coexist and pertain to Ca V 1 and Ca V 2 channels, respectively, coupling membrane depolarization to CREB phosphorylation and gene expression. Ca V 1 channels are advantaged in their voltage-dependent gating and use nanodomain Ca 2+ to drive local CaMKII aggregation and trigger communication with the nucleus. In contrast, Ca V 2 channels must elevate [Ca 2+ ] i microns away and promote CaMKII aggregation at Ca V 1 channels. Consequently, Ca V 2 channels are ∼10-fold less effective in signaling to the nucleus than are Ca V 1 channels for the same bulk [Ca 2+ ] i increase. Furthermore, Ca V 2-mediated Ca 2+ rises are preferentially curbed by uptake into the endoplasmic reticulum and mitochondria. This source-biased buffering limits the spatial spread of Ca 2+ , further attenuating Ca V 2-mediated gene expression.
Three-dimensional Reflection And Transmission Of Elastic Waves By An Array Of Cylinders

Abstract Three-dimensional scattering of elastic waves by an array of parallel and periodically spaced cylinders has been studied. The incident angles have been assumed arbitrary, so in the most general cases the scattered waves consist of not only the longitudinal and vertically polarized shear waves, but also the horizontally polarized shear wave. The scattered displacement field in the matrix medium has been formulated in terms of Fourier series. The reflection and transmission coefficients as well as the reflected and transmitted energies have been obtained using the boundary integral equation method. It has been shown that Wood's anomaly for electromagnetic waves also exists for elastodynamic waves. Finally, the reflection coefficient has been used to determine the scatterer density.