cssi/SciSciGPT-SciSciNet huggingface dataset:
Imaging of the intracranial venous system with a contrast-enhanced volumetric interpolated examination.

A contrast-enhanced interpolated, three-dimensional (3D) gradient-echo MR sequence with asymmetric k-space sampling, which we refer to as volumetric interpolated brain examination (VIBE), was evaluated for its depiction of the normal intracranial venous system and compared with two-dimensional (2D) time-of-flight (TOF) MR venography (MRV). Fifteen subjects underwent contrast-enhanced VIBE imaging (TR/TE 8 ms/4.4 ms, flip angle 18°, acquisition time, 2 min 20 s, voxel size approximately 1.5 mm3) and standard 2D TOF MRV (TR/TE 27 ms/9 ms, flip angle 35°). The presence of 19 venous structures per subject was assessed on maximum intensity projections (MIP) of the whole data set (whole-brain MIP) and on MIP images reconstructed spontaneously from source images (interactive MIP/source images). Results from a consensus reading where all imaging techniques and display modalities were available were taken as the standard of reference for the presence of venous structures. In addition, 10 subjects underwent both unenhanced and enhanced VIBE imaging. The value of subtracted data sets (unenhanced VIBE subtracted from enhanced VIBE) was then evaluated. Overall, VIBE provided a superior visualization of the cerebral veins than 2D TOF MRV (VIBE, sensitivity (reader 1/reader 2): 98%/99%, negative predictive value 64%/71%; TOF sensitivity: 85%/84%, negative predictive value 15%/15%; Wilcoxon signed-rank test VIBE vs TOF, p<0.001 for both readers). The VIBE interactive MIP/source images were superior to whole-brain MIP reconstructions. Image subtraction was not necessary for delineation of venous structures but improved small vein conspicuity. Contrast-enhanced VIBE acquisitions are faster and enable a visualization of the normal intracranial venous system superior to that of 2D TOF MRV.
Piezoelectricity Principles and Materials

This article starts with the general presentation of piezoelectric principles and equations. Both tensor notations and Voigt matrix notations are discussed. Subsequently, several types of electroactive materials are presented: piezoelectric ceramics, electrostrictive ceramics, piezoelectric polymers, etc. Various formulations of these materials are currently commercially available. The names lead zirconate titanate (PZT) (a piezoelectric ceramic), lead manganate niobate (PMN) (an electrostrictive ceramic), and polyvinylidene fluoride (PVDF) (a piezoelectric polymer), which have become widely used in structural health monitoring (SHM) sensor applications, are presented. A general perspective on piezoelectricity and ferroelectric ceramics, explaining some of the physical behavior underpinning their salient features, especially in relation to perovskite crystalline structures, is given. Piezoelectric polymers such as PVDF, which are flexible, resilient, and durable but produce less force, are presented. Magnetoactive materials such as the magnetostrictive Terfenol-D are also presented because they are used in some SHM sensor applications. Summary and conclusions wrap up the article. Keywords: piezoelectricity; ferroelectricity; lead zirconate titanate (PZT); piezoceramic; lead manganate niobate (PMN); electrostrictive ceramic; polyvinylidene fluoride (PVDF); piezopolymer; Terfenol-D; magnetostrictive; piezomagnetic
Relation of microstructure to constitutive equations

This chapter is devoted to deriving and using microstructural information to find constitutive equations, giving relationships between certain average quantities and the average fields. The physical situation is one in which corpuscular models can be highly useful in motivating the forms of the constitutive equations. In effect, the study of the mechanics of multicomponent fluids necessitates the study of the form of the momentum exchange term and the stress in the momentum equation. The study of these terms is aided by a physically appropriate corpuscular model, consisting of solutions for flows in this model, which are sometimes exact but usually approximate. Once these solutions are found, they can be averaged to find the force of interaction in the continuum equations.
Performance of a proposed determinative method for p-TSA in rainbow trout fillet tissue and bridging the proposed method with a method for total chloramine-T residues in rainbow trout fillet tissue

Chloramine-T is an effective drug for controlling fish mortality caused by bacterial gill disease. As part of the data required for approval of chloramine-T use in aquaculture, depletion of the chloramine-T marker residue (para-toluenesulfonamide; p-TSA) from edible fillet tissue of fish must be characterized. Declaration of p-TSA as the marker residue for chloramine-T in rainbow trout was based on total residue depletion studies using a method that used time consuming and cumbersome techniques. A simple and robust method recently developed is being proposed as a determinative method for p-TSA in fish fillet tissue. The proposed determinative method was evaluated by comparing accuracy and precision data with U.S. Food and Drug Administration criteria and by bridging the method to the former method for chloramine-T residues. The method accuracy and precision fulfilled the criteria for determinative methods; accuracy was 92.6, 93.4, and 94.6% with samples fortified at 0.5X, 1X, and 2X the expected 1000 ng/g tolerance limit for p-TSA, respectively. Method precision with tissue containing incurred p-TSA at a nominal concentration of 1000 ng/g ranged from 0.80 to 8.4%. The proposed determinative method was successfully bridged with the former method. The concentrations of p-TSA developed with the proposed method were not statistically different at p < 0.05 from p-TSA concentrations developed with the former method.
Electronic structure and magnetism of R 2 Fe 14 B ( R =Y,Nd) compounds

The linear muffin-tin orbitals (LMTO) method is used to calculate the self-consistent spin-polarized electronic structures of ${\mathit{R}}_{2}$${\mathrm{Fe}}_{14}$B (R=Y,Nd) compounds. The present results are compared with those of an earlier non-self-consistent calculation. The calculated results are in good agreement with the experimental data from photoemission, heat-capacity, and magnetic measurements.
Transmembrane Voltage of Opossum Esophageal Smooth Muscle and Its Response to Electrical Stimulation of Intrinsic Nerves

Abstract This study was designed to examine the transmembrane potential of esophageal circular smooth muscle both before and in response to electrical stimulation of the intrinsic neural plexus, and to determine if regional differences are present in these potentials. Transverse strips of the opossum esophagus were prepared from sites located 1,3,5, and 7 cm above the gastroesophageal junction and subjected to 1-s trains of square-wave pulses. The effects of varying pulse frequency, voltage, and duration were assessed by conventional microelectrode techniques. The latency of the electrical off response ranged from a mean value of 1.08 s at 5 Hz to 1.0 s at 16 Hz when measured in cells from strips 5 cm above the gastroesophageal junction. Associated with this increase in latency is both an increase in the mean amplitude of hyperpolarization and a fall in the rate of the ensuing depolarization. In contrast, an increase in pulse voltage or duration had no effect on electrical off response latency. Resting potential analyzed on a regional basis ranged from a mean of −52.8 mV to −43.5 mV in strips 7 cm and 1 cm above the gastroesophageal junction respectively. Electrical off response latencies also demonstrated regional differences ranging from 1.06 to 1.50 s in strips taken 7 cm and 3 cm above the gastroesophageal junction respectively. Associated with the prolonged latencies noted in the more aboral strips was a decrease in the average rates of both membrane hyperpolarization and ensuing depolarization. It can be concluded from these studies that (a) within a given region an increase in stimulus frequency increases the mean amplitude of hyperpolarization, decreases the rate of the ensuing depolarization, and prolongs the electrical off response latency; (b) mean resting potential of esophageal circular smooth muscle cell becomes gradually less negative in an oral to aboral direction; and (c) cells of the more aboral smooth muscle segments studied demonstrated a decrease in the average rates of both membrane hyperpolarization and ensuing depolarization, and a prolonged electrical off response latency.
Gonadotropin dose is negatively correlated with live birth rate: analysis of more than 650,000 assisted reproductive technology cycles

Objective To evaluate the correlation between total gonadotropin dose and live birth rate. Design Retrospective analysis. Setting Not applicable. Patient(s) A total of 658,519 fresh autologous cycles of in vitro fertilization (IVF) reported to the Society for Assisted Reproductive Technology from 2004 to 2012. Intervention(s) None. Main Outcome Measure(s) Logistic regression models were fitted to live birth rates with the use of categorized values for total FSH dose and number of oocytes retrieved as the primary predictor variables. To reduce the effect of the most significant confounders that may lead physicians to prescribe higher doses of FSH, additional analyses were performed limited to good-prognosis patients ( 2 , and no diagnosis of diminished ovarian reserve, endometriosis, or ovulatory disorder) and including duration of gonadotropin treatment. Result(s) Live birth rate significantly decreased with increasing FSH dose, regardless of the number of oocytes retrieved. The statistically significant decrease in live birth rate with increasing FSH dose remained in patients with good prognosis, and regardless of female age, except for women aged ≥35 years with 1–5 oocytes retrieved. Conclusion(s) This analysis suggests that physicians may wish to avoid prescribing a high dose of FSH. However, the results of this study do not justify the use of minimal-stimulation or natural-cycle IVF.
Integral equations as evolution equations

Abstract We study a class of time-dependent linear integrodifferential equations (VE) with the evolution equation approach. We determine the generators of a time-dependent evolution equation (DE) which is equivalent to the given integrodifferential equation. Under very general assumptions we prove the well-posedness and continuity of (VE) from the stability of (DE). The related question of convergence of a family of approximate solutions is examined. As an application, we include an example of hyperbolic integro-partial-differential equation to illustrate the theory.
The Caenorhabditis elegans ect-2 RhoGEF gene regulates cytokinesis and migration of epidermal P cells

A reduction-of-function mutation in ect-2 was isolated as a suppressor of the Multivulva phenotype of a lin-31 mutation. Analysis using markers indicates that this mutation causes defects in both the cytokinesis and migration of epidermal P cells, phenotypes similar to those caused by expressing a rho-1 dominant-negative construct. ect-2 encodes the Caenorhabditis elegans orthologue of the mouse Ect2 and Drosophila Pebble that function as guanine nucleotide exchange factors (GEFs) for Rho GTPases. The ect-2∷GFP reporter is expressed in embryonic cells and P cells. RNA interference of ect-2 causes sterility and embryonic lethality, in addition to the P-cell defects. We have determined the lesions of two ect-2 alleles, and described their differences in phenotypes in specific tissues. We propose a model in which ECT-2GEF not only activates RHO-1 for P-cell cytokinesis, but also collaborates with UNC-73GEF and at least two Rac proteins to regulate P-cell migration.
Effects of duration of ischemia and donor pretreatment with methylprednisolone or its macromolecular prodrug on the disposition of indocyanine green in cold-preserved rat livers

Purpose. Cold preservation of the liver before transplantation may change uptake and excretory functions of hepatocytes. We hypothesized that an increase in the duration of preservation would result in a progressive decrease in the hepatic uptake and/or biliary excretion of indocyanine green (ICG), which would be attenuated by pharmacologic interventions.
Transcriptome analysis of HTLV-1-infected cells in comparison to the normal and Tax-expressing T cells

The transactivator protein of HTLV, Tax, is required for the activity of viral promoter LTR (long terminal repeat) and is capable of regulating both virus and host transcription. Tax is known to interact with several cellular factors including CREB/ATF, NF-κB and those involved in chromatin remodeling, cell cycle and DNA damage/repair. However, the process of Tax-mediated transactivation of chromosomally integrated LTR is not fully understood. Therefore, we have performed an extensive Protein/DNA transcription factor array (PD array I, Panomics) analysis on the HTLV-1 infected cells (MT-2) in comparison to the Tax-expressing cells (C8166) and normal T cells (Jurkat). Besides known factors, significant changes were observed in several new nuclear and cytoplasmic factors such as RxR, AP-1, AP-2, in both MT-2 and C8166 cells as compared to Jurkat indicating an overlap with viral replication and Tax-activity. Interestingly, MT-2 cells demonstrated the down-regulation of majority of the factors analyzed while several nuclear (NF-E1, NF-E2, TFIID) and cytoplasmic (MEF-1, RAR) factors were upregulated in C8166 suggesting Tax activity independent of viral replication. Overall, this data suggest that more scrutiny on nuclear and cytoplasmic factors associated with Tax transactivation process is needed to clearly elucidate the mechanism underlying adult-T-cell leukemia and tropical spastic paraparesis associated with HTLV-1 infection.
A proposal on the function of unsaturated fatty acids and ionic lipids: the role of potential compaction in biological membranes

Abstract Unsaturated fatty acids are constituents of nearly all biological membranes. They are always present in membranes which possess transmembrane potentials. Two completely different biosynthetic routes have evolved (aerobic and anaerobic) for placing cis double bonds in the 9 position on the fatty acids of membrane lipids. Bacterial membranes contain primarily monounsaturated fatty acids, whereas eukaryote membranes contain a significant fraction of polyunsaturated fatty acids. The polyunsaturated fatty acids are concentrated in organelles, such as chloroplasts and mitochondria that are known to manipulate transmembrane potentials. I propose that the function of the unsaturated fatty acids is to facilitate the transmission of a local compaction of the membrane (in response to a transmembrane potential) laterally through the membrane. The role of the cis double bond at position 9 is twofold: first to create a kink in the chains of a large fraction of membrane fatty acids enhancing the separation of two regions in the membrane and second to enhance the rigidity of the membrane in the region between the head group and the 9 double bond. This ordered region contains those carbons proximal to the 9 carbon and which are in a regular array of trans conformations. The presence of a reasonable proportion of cis double bonds at position 9 will tend to maintain these trans conformations utilizing pi-pi (van der Waals) interactions between adjacent hydrocarbon chains at position 9. The disordered region contains the carbons distal to the 9 carbon. These have greater degrees of freedom and considerable gauche conformations. The role of the double bonds in the polyunsaturated fatty acids distal to carbon 9 is to facilitate trans bilayer pi-pi (van der Waals) interactions enhancing compaction of the bilayer during the electrostriction. I further propose that it is the function of the ionic headgroups to form an interlocking polyionic network which constitutes an elastic sheet. These ionic interactions would serve as the restoring force converting the compaction into a wave. The facilitation of the compaction of the bilayer together with the polyionic restoring force permits the membrane to transmit conformational changes from one transmembrane protein to another. Since transmembrane potentials are created and responded to by proteins each in a single location, it is thus proposed that a potential compaction wave emanates from the first protein in all directions in the plane of the membrane. The proposed wave would have both physical and electrical components. The electrohydrodynamic wave would require that the compaction oscillations be coupled to an oscillating electrical field. These proposals are applied to mitochondrial oxidative phosphorylation, and to transport across biological membranes.
Increase of yield of serum from samples of blood.

THE usual procedure for obtaining serum from clotted blood is to detach (rim) the clot from the collecting vessel, allow the clot to retract for several hours, and centrifuge at 500–1,000g. The procedure is not only time-consuming, but often results in much haemolysis ; in addition the yields of serum vary greatly from sample to sample. By using stronger centrifugal force and thromboplastin, I have been able to obtain serum in high yields, within 1 h after bleeding, and with a minimum of haemolysis.
What's the use of calling Du Bois a pragmatist?

: Was W. E. B. Du Bois a pragmatist? Does it matter? This essay argues that reading Du Bois as a pragmatist highlights aspects of his work and life that might otherwise go unnoticed, while also highlighting aspects of pragmatism that often go unappreciated. In addition, this double revelation may help restore to us some important resources for dealing with current social problems.
Pharmacotherapy in spinal cord injury: a critical review of recent developments.

Traumatic and ischemic injuries to the CNS, including spinal cord, cause tissue damage through both direct (primary) and indirect (secondary) mechanisms (1,2). Experimental evidence over the past 2 decades has demonstrated that delayed, secondary injury may play a major contributing role in the deve
Optical logic operations using photoinduced anisotropy in bacteriorhodopsin films

We constructed an optical system for performing 2D logic operations. We demonstrated the logic operations of OR, NOR, XOR, AND. The photoinduced dichroism of Bacteriorhodopsin (bR) is the physical mechanism exploited in the optical system. In its normal state with no light illumination a bR doped polymer film is isotropic with random distribution of bR molecules. When excited by linearly polarized light, only those bR molecules whose transition dipole moments for absorption lie in or near the direction of the electric field ar bleached at the actinic light wavelength due to the B to M transition. If a probe beam is incident in the regions illuminated by the actinic light it will no longer be interacting with an isotropic film. The film is now anisotropic and dichroic. Due to dichroism the actinic light illumination produces an angular rotation of the plane of polarization of the probe beam. In the experiments the bR film is kept between two crossed polarizers to get zero output from the probe beam at a screen when no actinic light is incident on the bR film. The two polarizers and the screen are kept in the path of the probe beam. There are two actinic light beams that induce dichroism and they are made orthogonally polarized with respect to each other by the use of a polarization rotator. The polarization rotator can be arranged so that their polarizations are made parallel for some of the logic operations. The plane of polarization of these two actinic beams are at 45 degrees to the pane of polarization of the probe beam. The combination of rotation of the analyzer and the polarization rotation of one of the actinic beams allows for many logic operations to be performed. No interference recordings are involved in the experiments and hence vibration isolation systems are not required. A coherent source is not a requirement either since a white light source with an appropriate wavelength filter can induce photoanisotropy in the bR film.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Deformation of PbSn eutectic alloys at relatively high strain rates

Abstract The steady-state stresses of lead-tin eutectic alloy (Pb-62Sn) samples of mean phase diameter from 5.5 to 9.9 μm were measured over a range of temperatures from 0° to 160°C and strain rates from 2.66 × 10−5 to 1.33 × 10−2 s−1. The alloy exhibited both conventional and superplastic deformation over this range of experimental variables. The data were consistent with the assumption that the two deformation behaviors occur simultaneously via independent mechanisms. The data may be represented by the dimensionless constitutive relation γ ∗ = 900(τ ∗ ) 1.96 (d ∗ −1.8 exp (−11,500/RT) + (1.3 × 10 15 )(τ ∗ ) 7.1 exp (−19,400/RT) , where the first term on the right gives the rate of superplastic deformation and the second term gives the rate of conventional deformation.
ErbB-2 Activates Stat3α in a Src- and JAK2-dependent Manner

Stats (signal transducer and activator of transcription) are latent transcription factors that translocate from the cytoplasm to the nucleus. Constitutive activation of Stat3 alpha by upstream oncoproteins and receptor tyrosine kinases has been found in many human tumors and tumor-derived cell lines. Constitutively activated Stat3 alpha is often correlated with the activation of ErbB-2, a member of the EGFR family. To explore the involvement of ErbB-2 in the activation of Stat3 and the mechanism underlying this event, an ErbB-2 point mutant was used as a model of constitutively activated receptor. Phenylalanine mutations (Y-->F) were made in the autophosphorylation sites of the receptor, and their ability to activate Stat3 alpha was evaluated. Our results suggest that Stat3 alpha and JAK2 associates with ErbB-2 prior to phosphorylation of the receptor and that full activation of Stat3 alpha by ErbB-2 requires the participation of other non-receptor tyrosine kinases. Both Src and Jak2 kinases contribute to the activation of Stat3 alpha but Src binds to ErbB-2 only when the receptor is phosphorylated. Our results also suggest that tyrosine 1139 may be important for Src homology 2 domain association because a mutant lacking this tyrosine reduces the ability of the Src homology 2 domain to bind to ErbB-2 and significantly decreases its ability to activate Stat3 alpha.
Effects of Pyridinolcarbamate on the Cardiovascular System of the Anesthetized Dog after Bilateral Cervical Vagotomy

Pyridinolcarbamate (PDC) was injected at a dose of 10 mg/Kg of body weight into the femoral vein of anesthetized dogs with a bilateral cervical vagosympathotomy. At this dose, it produced a transitory decrease in systolic, diastolic, and mean arterial pressure and an increase in heart rate. In addition, it produced a more prolonged increase in stroke volume, peak aortic flow, cardiac output, and left ventricular minute work. It also lowered peripheral resistance and apparently decreased the vaso-constrictor action of injected norepinephrine (1 mug of active base/Kg of body weight). These data are consistent with the view that PDC has a direct action on the heart that is similar to that of norepinephrine and that PDC blocks the alpha adrenergic receptors of the systemic resistance vessels.
Economic Deprivation and Early Childhood Development

We consider 3 questions regarding the effects of economic deprivation on child development. First, how are developmental outcomes in childhood affected by poverty and such poverty correlates as single parenthood, ethnicity, and maternal education? Second, what are the developmental consequences of the duration and timing of family economic deprivation? And, third, what is the comparative influence of economic deprivation at the family and neighborhood level? We investigate these issues with longitudinal data from the Infant Health and Development Program. We find that family income and poverty status are powerful correlates of the cognitive development and behavior of children, even after accounting for other differences--in particular family structure and maternal schooling--between low- and high-income families. While the duration of poverty matters, its timing in early childhood does not. Age-5 IQs are found to be higher in neighborhoods with greater concentrations of affluent neighbors, while the prevalence of low-income neighbors appears to increase the incidence of externalizing behavior problems.
PhiSiGns: an online tool to identify signature genes in phages and design PCR primers for examining phage diversity

Phages (viruses that infect bacteria) have gained significant attention because of their abundance, diversity and important ecological roles. However, the lack of a universal gene shared by all phages presents a challenge for phage identification and characterization, especially in environmental samples where it is difficult to culture phage-host systems. Homologous conserved genes (or "signature genes") present in groups of closely-related phages can be used to explore phage diversity and define evolutionary relationships amongst these phages. Bioinformatic approaches are needed to identify candidate signature genes and design PCR primers to amplify those genes from environmental samples; however, there is currently no existing computational tool that biologists can use for this purpose. Here we present PhiSiGns, a web-based and standalone application that performs a pairwise comparison of each gene present in user-selected phage genomes, identifies signature genes, generates alignments of these genes, and designs potential PCR primer pairs. PhiSiGns is available at ( http://www.phantome.org/phisigns/ ; http://phisigns.sourceforge.net/ ) with a link to the source code. Here we describe the specifications of PhiSiGns and demonstrate its application with a case study. PhiSiGns provides phage biologists with a user-friendly tool to identify signature genes and design PCR primers to amplify related genes from uncultured phages in environmental samples. This bioinformatics tool will facilitate the development of novel signature genes for use as molecular markers in studies of phage diversity, phylogeny, and evolution.
Involvement in Voluntary Organizations: How Older Adults Access Volunteer Roles?

This study examines how older adults access organizational volunteer roles and what socio-structural factors are associated with the access. Using the data from the Current Population Survey (U.S. Department of Commerce, Bureau of the Census, 2002), bivariate analyses show that there are variations in access to volunteer roles across types of organizations. Results from multinomial logistic regressions indicate that education, income, age, and race are associated with the ways that older adults access volunteer roles. Voluntary organizations are advised to approach older adults directly, use current volunteers to recruit potential ones, publicize their organizational goals, and disseminate relevant information in efforts to improve access of older adults to volunteer roles.
Study of ultra-thin Ge/Si strained layer superlattice

Abstract Ultra-thin Ge/Si strained layer superlattices (SLSs) with periodicities of a few monolayers (MLs) have been successfully grown and characterized by Raman scattering spectroscopy. Structures with alternating Ge and Si layers were grown on Si substrates of different orientations. A thick 200 nm Ge 0.4 Si 0.6 buffer layer was grown prior to the growth of the superlattice to make the strain distribution of the superlattice symmetrical and thus to maintain the pseudomorphic growth of the superlattices. Folded acoustic phonon peaks observed from these Ge/Si SLS samples can be used to determine the superlattice periodicity. The observed optical phonon frequencies were found to depend strongly superlattice periodicity. A quantitative interpretation of this phenomena was presented. Subsequent annealing of these samples reveals that the transition from pure Ge and /or Si layers to Ge x Si 1− x alloy becomes more pronounced as the annealing time and temperature increase.
The composition of beef heart cardiolipins isolated by solvent and chromatographic fractionation

A method is described for the isolation of cardiolipin from beef heart lipids by a single pass through a silica gel column. The isolated cardiolipin was free of neutral lipids and phospholipids and accounted for 10% of total phospholipid phosphorus. It was compared to commercial cardiolipins prepared by the Pang-born method of selective precipitation. Analysis for fatty acids, glycerol and phosphorus revealed a molar ratio of 2∶1.5∶1 for both preparations, provided the fatty acid esters were assayed colorimetrically. If the fatty acids were determined by titration, the commercial cardiolipin had a molar ratio of fatty acid to phosphorus of 1.6, while ours remained at 2.0. Upon hydrolysis with acetic acid, the former yielded 76% water-soluble phosphorus, the latter only 2%. Both cardiolipins contained over 90% C-18 fatty acids, with our preparation containing 76% linoleate, the commercial preparation, 90%. After alkaline hydrolyses a component was isolated from the commercial cardiolipin which represented 15.5% of the total weight. It developed an interfering pigment in the fatty acid ester determination but has not been identified. After its removal analysis demonstrated three fatty acids per molecule of the commercial cardiolipin.
Inducible Peroxidases Mediate Nitration of Anopheles Midgut Cells Undergoing Apoptosis in Response to Plasmodium Invasion

Abstract Plasmodium berghei invasion of Anopheles stephensi midgut cells causes severe damage, induces expression of nitric-oxide synthase, and leads to apoptosis. The present study indicates that invasion results in tyrosine nitration, catalyzed as a two-step reaction in which nitric-oxide synthase induction is followed by increased peroxidase activity. Ookinete invasion induced localized expression of peroxidase enzymes, which catalyzed protein nitration in vitro in the presence of nitrite and H2O2. Histochemical stainings revealed that when a parasite migrates laterally and invades more than one cell, the pattern of induced peroxidase activity is similar to that observed for tyrosine nitration. In Anopheles gambiae, ookinete invasion elicited similar responses; it induced expression of 5 of the 16 peroxidase genes predicted by the genome sequence and decreased mRNA levels of one of them. One of these inducible peroxidases has a C-terminal oxidase domain homologous to the catalytic moiety of phagocyte NADPH oxidase and could provide high local levels of superoxide anion (), that when dismutated would generate the local increase in H2O2 required for nitration. Chemically induced apoptosis of midgut cells also activated expression of four ookinete-induced peroxidase genes, suggesting their involvement in general apoptotic responses. The two-step nitration reaction provides a mechanism to precisely localize and circumscribe the toxic products generated by defense reactions involving nitration. The present study furthers our understanding of the biochemistry of midgut defense reactions to parasite invasion and how these may influence the efficiency of malaria transmission by anopheline mosquitoes.
Differential oxidant potential of carcinogenic and weakly carcinogenic estrogens: Involvement of metabolic activation and cytochrome P450

Different estrogens vary in their carcinogenic potential despite having similar hormonal potencies; however, mechanisms of estrogen-induced carcinogenesis remain to be fully elucidated. It has been hypothesized that generation of reactive estrogen-quinones and oxidative stress, both of which result from metabolic activation of estrogens, play an essential role in estrogen-induced carcinogenesis. This hypothesis was tested using the estrogen-receptor (ER)-α-positive hamster kidney tumor (H301) and the human breast cancer (MCF-7) cell lines. Estrogens with differing carcinogenic potentials were compared in terms of their capacities to induce 8-iso-prostaglandin F2α (8− iso-PGF2α), a marker of oxidative stress. Tumor cells were treated with either 17β-estradiol (E2), a carcinogenic estrogen or 17-α-ethinylestradiol (EE), a weakly-carcinogenic estrogen. Tumor cells were also treated with α-naphthoflavone, a cytochrome P450 inhibitor, or a combination of α-naphthoflavone and E2 to study the effect of metabolic activation of E2 on E2-induced oxidative stress. H301 cells treated with E2 displayed time- and dose-dependent increases in 8-iso-PGF2α, compared to controls; treatment with 10 nM E2 resulted in a maximal 4-fold induction following 48 h of treatment. In contrast, H301 cells treated with EE did not display an increase in 8-iso-PGF2α compared with controls. In H301 cells cotreated with α-naphthoflavone and E2, α-naphthoflavone inhibited the E2-induced increase in 8-iso-PGF2α. These data indicate that a carcinogenic estrogen shows strong oxidant potential, whereas a weakly-carcinogenic estrogen shows poor oxidant potential. Furthermore, inhibiting metabolic activation of a carcinogenic estrogen blocks its oxidant potential. Our data support the hypothesis that metabolic activation and subsequent generation of oxidative stress may play critical roles in estrogen-induced carcinogenesis. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:37–42, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20005
Changing Attitudes toward Marriage and Children in Six Countries

This article examines changes in attitudes toward marriage and children in Austria, (West) Germany, Great Britain, Ireland, the Netherlands, and the U.S. using the data from the 1988, 1994, and 2002 waves of the International Social Survey Programe (ISSP). Consistent with the ideas of the second demographic transition and the rise of post-materialism, public opinion in these countries is shifting away from traditional norms of universal marriage and childbearing. Female, never married, better educated, employed, and relatively secularized individuals hold less traditional views about marriage and children in all countries. Furthermore, attitudes of married and never married in Austria and Germany, males and females in the U.S. became more polarized, which might be attributed to public policies to increase fertility and promote traditional marriage in these countries. Large unexplained cross-national differences also point at the importance of contextual factors for understanding recent changes in support ...
Inelastic Scattering of Protons by Ca 40

The inelastic scattering of protons by ${\mathrm{Ca}}^{40}$ was investigated with the MIT-ONR electrostatic generator and a 180-degree magnetic spectrograph. Bombarding energies from 6.54 to 8.15 Mev were used, targets were made of calcium, and the reaction angle was 90 degrees. Excited states of ${\mathrm{Ca}}^{40}$ were found at 3.348\ifmmode\pm\else\textpm\fi{}0.004, 3.730\ifmmode\pm\else\textpm\fi{}0.004, 3.900\ifmmode\pm\else\textpm\fi{}0.004, 4.483\ifmmode\pm\else\textpm\fi{}0.005, 5.202\ifmmode\pm\else\textpm\fi{}0.008, 5.241\ifmmode\pm\else\textpm\fi{}0.006, 5.272\ifmmode\pm\else\textpm\fi{}0.006, 5.606\ifmmode\pm\else\textpm\fi{}0.009, 5.621\ifmmode\pm\else\textpm\fi{}0.008, 5.901\ifmmode\pm\else\textpm\fi{}0.008, and 6.029\ifmmode\pm\else\textpm\fi{}0.008 Mev.
Optimum sensors integration for multi-sensor multi-target environment for ballistic missile defense applications

Multi-sensor networks may face resource limitations in a dynamically evolving multiple target tracking scenario. It is necessary to task the sensors efficiently so that the overall system performance is maximized within the system constraints. The central sensor resource manager may control the sensors to meet objective functions that are formulated to meet system goals such as minimization of track loss, maximization of probability of target detection, and minimization of track error. This paper discusses the variety of techniques that may be utilized to optimize sensor performance for either near term gain or future reward over a longer time horizon.
Female Exclusion from Religious Roles: A Cross-Cultural Test of Competing Explanations

Data from a cross-cultural sample of 93 societies were used to test three theories that could account for the exclusion of women from community religious roles: gynephobia, resource theory, and differentiated social spheres. Results from a multiple regression analysis suggest that only resource theory has any ability to predict societal patterns excluding females from religious roles. In particular, it is most effective in predicting the likelihood women will be allowed to assume the role of shaman. Women are most likely to be shamans in societies in which they are highly influential in kin networks and yet retain little control of property. These factors are discussed as they relate to opportunities for social sponsorship and to a functional aspect of social marginality that favors selection for shamanship. Despite widespread interest in the ways in which sexist constraints are imposed on women, little is known about the operation of such mechanisms in specific institutional contexts. For example, the exclusion of women from full participation in the life of the religious institution has been recently remarked (see, for example, Driver; Ermath; Harkness; Neal, a, b; Swidler; Wallace), but few explanations have been offered to account for the phenomenon and fewer empirical tests of theoretical insights have been applied. Lehman (a, b), in the most sociologically insightful studies to date, has examined the effects of demographic, social psychological, and organizational setting variables on congregants' attitudes toward women ministers. But his work fixes principally on the characteristics of congregants and congregational dynamics, rather than on characteristics of the aggregate of prospective female clergy, (such as the degree of power they *I thank Lynda Lane Martin for her invaluable assistance in the coding and analyses of data presented in this paper. It is a revised version of a paper read at the 1979 meetings of the Society for the Scientific Study of Religion. I am grateful also to Martin King Whyte for providing previously unpublished data that I have used and to Gerhard Lenski and anonymous referees for their helpful comments on a previous draft. ? 1982 The University of North Carolina Press. 0037-77321821010079-98$02.00
Identification of a functional binding site for activin on the type I receptor ALK4.

Activins, like other members of the transforming growth factor-β (TGF-β) superfamily, initiate signaling by assembling a complex of two types of transmembrane serine/threonine receptor kinases classified as type II (ActRII or ActRIIB) and type I (ALK4). A kinase-deleted version of ALK4 can form an inactive complex with activin and ActRII/IIB and thereby acts in a dominant negative manner to block activin signaling. Using the complex structure of bone morphogenetic protein-2 bound to its type I receptor (ALK3) as a guide, we introduced extracellular domain mutations in the context of the truncated ALK4 (ALK4-trunc) construct and assessed the ability of the mutants to inhibit activin function. We have identified five hydrophobic amino acid residues on the ALK4 extracellular domain (Leu40, Ile70, Val73, Leu75, and Pro77) that, when mutated to alanine, have substantial effects on ALK4-trunc dominant negative activity. In addition, eleven mutants partially affected activin binding to ALK4. Together, these residues likely constitute the binding surface for activin on ALK4. Cross-linking studies measuring binding of 125I-activin-A to the ALK4-trunc mutants in the presence of ActRII implicated the same residues. Our results indicate that there is only a partial overlap of the binding sites on ALK4 and ALK3 for activin-A and bone morphogenetic protein-2, respectively. In addition three of the residues required for activin binding to ALK4 are conserved on the type I TGF-β receptor ALK5, suggesting the corresponding region on ALK5 may be important for TGF-β binding.
On coupling many small systems for transaction processing

The prospect of coupling a large number of small inexpensive microprocessor based systems to deliver the performance of a large transaction processing system at lower cost has not been realized, to date. Inter-system interference, multi-system coupling protocol overhead and the increased processing time for smaller systems can cause considerable degradation. A methodology is developed to determine the number of processors needed to satisfy transaction throughput and response time requirements for processors of different MIPS (sizes). The minimum MIPS per processor required to satisfy response time, throughput and utilization constraints in a transaction processing complex of N coupled systems is also determined, by using an approximate analytical model driven by measured workload parameters. Despite large assumed cost advantages on a per MIPS basis we find that small systems do not match up to the cost/performance of some larger systems. Besides multi-system's coupling degradation, there is a small system effect. Because of the increased transaction execution time in smaller systems, transaction hold on to resources longer, thereby causing increased inter-system interference. Our cost criterion indicates that there is an optimum processor size below which total system costs would increase appreciably. Ways to reduce the inter-system interference and coupling protocol overheads are investigated and shown to shift this optimum.
Inhibition of Desipramine Hydroxylation (Cytochrome P450-2D6) in Vitro by Quinidine and by Viral Protease Inhibitors: Relation to Drug Interactions in Vivo

Pharmacokinetic drug interactions with viral protease inhibitors are of potential clinical importance. An in vitro model was applied to the quantitative identification of possible interactions of protease inhibitors with substrates of cytochrome P450-2D6. Biotrans-formation of desipramine (DMI) to hydroxydesipramine (OH-DMI), an index reaction used to profile activity of human cytochrome P450-2D6, was studied in vitro using human liver microsomes. Quinidine and four viral protease inhibitors currently used to treat human immunodeficiency virus infection were tested as chemical inhibitors in this system. Formation of OH-DMI from DMI was consistent with Michaelis–Menten kinetics, having a mean Km value of 11.7 µM (range: 9.9–15.3 µM). Quinidine, a highly potent and relatively selective inhibitor of P450-2D6, strongly inhibited OH-DMI formation with an apparent competitive mechanism, having a mean inhibition constant of 0.16 µM (range: 0.13–0.18 µM). All four protease inhibitors impaired OH-DMI formation; the pattern was consistent with a mixed competitive-noncompetitive mechanism. Mean inhibition constants (small numbers indicating greater inhibiting potency) were as follows: ritonavir, 4.8 µM; indinavir, 15.6 µM; saquinavir, 24.0 µM; nelfinavir, 51.9 µM. In a clinical pharmacokinetic study, coadminis-tration of ritonavir with DMI inhibited DMI clearance by an average of 59%. The in vitro findings, together with observed plasma ritonavir concentrations, provided a reasonable quantitative forecast of this interaction, whereas estimated unbound plasma or intrahepatic ritonavir concentrations yielded poor quantitative forecasts. Thus the in vitro model correctly identifies ritonavir as a potent and clinically important inhibitor of human P450-2D6. Other protease inhibitors may also inhibit 2D6 activity in humans, but with lower potency than ritonavir.
Beyond milk and the good breast reconfiguring the maternal function in psychoanalytic dyads

This paper addresses the gender of the analyst as an important factor in the shaping of the analytic experience. Specifically, it focuses on the notion that female analysts bring something different from what male analysts bring to the analytic dyad and that this influences and shapes the analysts’ translation of the patients’ experience—determining treatment course and therapeutic enactments. It begins with the idea that, for some men, working with a female analyst may ease the processing and metabolization of their aggression—allowing for a (re) integration of it with their sexuality and desire. The clinical material of a male analysand who sought treatment from a woman analyst is used to explore this idea within a post‐Lacanian framework incorporating Kristeva's work on the maternal chora, the imaginary father or third, and the journey that the infant must make from the real to the symbolic, from biology to desire.
Materials science: Breakthrough for protons

The atomically thin material called graphene is impermeable to atoms as small as helium. The finding that protons can pass through it might enable new kinds of membrane to be developed and aid research into fuel cells. See Letter p.227 A perfect graphene sheet is impermeable to all atoms and molecules: even hydrogen, the smallest of atoms, is not expected to penetrate through graphene's dense electronic cloud within billions of years. This characteristic is thought to extend to other two-dimensional crystals such as hexagonal boron nitride and molybdenum disulphide. Sheng Hu and colleagues now show that, surprisingly, monolayers of graphene and hexagonal boron nitride (but not molybdenum disulphide) are highly permeable to protons. In combination with their stability, this establishes these monolayers as promising candidates for use in many hydrogen-based technologies.
Learning better transliterations

We introduce a new probabilistic model for transliteration that performs significantly better than previous approaches, is language-agnostic, requiring no knowledge of the source or target languages, and is capable of both generation (creating the most likely transliteration of a source word) and discovery (selecting the most likely transliteration from a list of candidate words). Our experimental results demonstrate improved accuracy over the existing state-of-the-art by more than 10% in Chinese, Hebrew and Russian. While past work has commonly made use of fixed-size n-gram features along with more traditional models such as HMM or Perceptron, we utilize an intuitive notion of "productions", where each source word can be segmented into a series of contiguous, non-overlapping substrings of any size, each of which independently transliterates to a substring in the target language with a given probability. To learn these parameters, we employ Expectation-Maximization (EM), with the alignment between substrings in the source and target word training pairs as our latent data. Despite the size of the parameter space and the 2(|w|-1) possible segmentations to consider for each word, by using dynamic programming each iteration of EM takes O(m^6 * n) time, where m is the length of the longest word in the data and n is the number of word pairs, and is very fast in practice. Furthermore, discovering transliterations takes only O(m^4 * w) time, where w is the number of candidate words to choose from, and generating a transliteration takes O(m2 * k2) time, where k is a pruning constant (we used a value of 100). Additionally, we are able to obtain training examples in an unsupervised fashion from Wikipedia by using a relatively simple algorithm to filter potential word pairs.