cssi/SciSciGPT-SciSciNet huggingface dataset:
Rapid Kinetics of Regulator of G-protein Signaling (RGS)-mediated Gαi and Gαo Deactivation Gα SPECIFICITY OF RGS4 AND RGS7

Abstract Regulator of G-protein signaling (RGS) proteins accelerate GTP hydrolysis by Gα subunits speeding deactivation. Gα deactivation kinetics mediated by RGS are too fast to be directly studied using conventional radiochemical methods. We describe a stopped-flow spectroscopic approach to visualize these rapid kinetics by measuring the intrinsic tryptophan fluorescence decrease of Gα accompanying GTP hydrolysis and Gα deactivation on the millisecond time scale. Basal k cat values for Gαo, Gαi1, and Gαi2 at 20 °C were similar (0.025–0.033 s−1). GlutathioneS-transferase fusion proteins containing RGS4 and an RGS7 box domain (amino acids 305–453) enhanced the rate of Gα deactivation in a manner linear with RGS concentration. RGS4-stimulated rates could be measured up to 5 s−1 at 3 μm, giving a catalytic efficiency of 1.7–2.8 × 106 m −1 s−1 for all three Gα subunits. In contrast, RGS7 showed catalytic efficiencies of 0.44, 0.10, and 0.02 × 106 m −1s−1 toward Gαo, Gαi2, and Gαi1, respectively. Thus RGS7 is a weaker GTPase activating protein than RGS4 toward all Gα subunits tested, but it is specific for Gαo over Gαi1 or Gαi2. Furthermore, the specificity of RGS7 for Gαo does not depend on N- or C-terminal extensions or a Gβ5 subunit but resides in the RGS domain itself.
‘Vavilov II’, a New Siberian Wheatgrass Cultivar with Improved Persistence and Establishment on Rangelands

Vavilov II' Siberian wheatgrass (Agropyron fragile (Roth) Candargy) (Reg. No. CV-30, PI 653686) was released by the USDA- ARS, the U.S. Army-Engineer Research and Development Center, Utah Agricultural Experiment Station, and the USDA- NRCS. Vavilov II was developed for reseeding sandy soils on disturbed rangelands dominated by annual weeds as a result of severe disturbance, frequent fi res, and soil erosion. Selection emphasis in Vavilov II was on seedling establishment and stand persistence. During the establishment year, Vavilov II had increased numbers of seedlings per unit area (m 2
Retrogressive regime drift within a theory of emergent order

This paper explores the robustness of systems of political economy from within an emergent perspective. Robustness is a quality of the nexus of relationships that emerge within a political economy, and particular attention is given to processes of regime drift that might generate retrogression within a political economy. The central claim advanced here is that robustness is facilitated through polycentric organizational arrangements that entail high degeneracy, while fragility and the emergence of decadence is facilitated in relatively hierarchical arrangements that possess low degeneracy.
Renal dysfunction but not cystic change is ameliorated by neonatal epidermal growth factor in bpk mice

BALB/c mice homozygous for the bpk gene exhibit a form of autosomal recessive (AR) polycystic kidney disease (PKD) with massive collecting duct cysts, common bile duct dilation and chaotic intrahepatic bile ducts/portal triads. The combined renal and biliary pathology mimics much of the pathology seen in human ARPKD. Murine models of ARPKD generally have a reduced renal expression of epidermal growth factor (EGF) and an increased expression of EGF receptors (EGF-R). However, the role that EGF and EGF-R play in the progression of PKD has been unclear. Evidence from various model systems/ages of treatment produces conflicting results. Treating neonatal C57BL/6J-cpk mice with EGF ameliorates the renal pathology and dysfunction while treating 2- and 3-week-old bpk mice with an EGF-receptor tyrosine kinase inhibitor also ameliorates ARPKD. Therefore, to determine whether neonatal EGF treatment would accelerate or inhibit the progression of the PKD in bpk mice, we administered exogenous EGF (1 µg/g body weight subcutaneously) daily from postnatal days 3–9 (a critical period for tubule maturation). Neonatal EGF treatment but not sham treatment retarded the development of azotemia and common bile duct dilation and the chaotic hepatic triad changes in cystic mice. However, EGF treatment neither reduced the severity of the renal cystic pathology nor reduced the degree of cystic enlargement of the kidneys. Cystic mice treated past 9 days of age died prior to their scheduled termination at 21 days of age. The role of EGF in the progression of polycystic kidney disease in bpk mice is relatively complicated, with neonatal treatment being associated with some amelioration of the renal dysfunction and extrarenal pathology without an effect on the renal pathology. Continuation of treatment beyond 9 days increased morbidity. Therefore, in discussing the role of EGF or EGF receptor in mediating the pathophysiology of PKD, the stage of development may be an important consideration.
Urogenital tract carcinoma metastatic to the head and neck

A 9-year review of our experience with head and neck metastases from 845 urogenital tract tumors of the kidney, prostate, bladder, testicle, spermatic cord, penis, urethra, and ureter was performed. Thirty-one (3.7%) of these tumors developed metastases to the cervical and supraclavicular lymph nodes, scalp, thyroid gland, thyroid cartilage, parotid gland, retroorbit, mandible, nasal cavity, and paranasal sinuses. Unusual cases and a review of the literature are presented. The frequency of such metastases to the head and neck from various primaries, diagnostic application of current immunohistochemical methodology, and therapeutic alternatives are emphasized.
Differential Regulation of Membrane-Associated Mucins in the Human Ocular Surface Epithelium

Purpose Membrane-associated mucins present in the apical cells of the ocular surface epithelium (MUC1, -4, and -16) are believed to contribute to the maintenance of a hydrated and wet-surfaced epithelial phenotype. Serum and retinoic acid (RA) have been used to treat drying ocular surface diseases. The goal of this study was to determine whether serum or RA regulates the production of membrane-associated mucins in human conjunctival epithelial cells. Methods A telomerase-immortalized human conjunctival epithelial cell line (HCjE) was used. Cells were cultured in serum-free medium to confluence and then cultured with either 10% calf serum or with 100 nM RA for 0 to 72 hours. Conventional RT-PCR was used to determine the expression of retinoic acid receptors (RARs) and quantitative real-time PCR was used to investigate the mRNA expression of MUC1, -4, and -16. Protein levels were assayed by immunoblot analysis, using the antibodies HMFG-2, 1G8, or OC125, which are specific to MUC1, -4 and -16, respectively. To determine whether RA-associated MUC4 mRNA induction is a direct or indirect effect, HCjE cells were treated with RA and the protein synthesis inhibitor cycloheximide (1.0 microg/mL) for 12 hours. Results MUC1 and -16, but not -4, mRNAs were detectable in HCjE cells grown in serum-free medium. Real-time PCR revealed that MUC4 mRNA was significantly induced by serum 3 hours after its addition, and that MUC1 and MUC16 mRNA levels were significantly upregulated at 72 hours. Western blot analysis demonstrated that the MUC1, -4, and -16 proteins increased over time after addition of serum. Conventional RT-PCR analysis demonstrated that RAR-alpha and -gamma mRNA were expressed in native human conjunctival tissue as well as in the HCjE cells. Treatment with RA upregulated the expression of both MUC4 and -16 mRNA and protein, but MUC1 was unaffected. Because the protein synthesis inhibitor cycloheximide did not prevent the RA-associated induction of MUC4 mRNA, the action of RA on the MUC4 promoter may be direct. Conclusions The membrane-associated mucins of the ocular surface epithelia, MUC1, -4, and -16, are differentially regulated by serum and RA in the telomerase-immortalized human conjunctival epithelial cell line. Serum derived from vessels in the conjunctiva may play an important role in mucin regulation in the ocular surface epithelia. These data also support the clinical efficacy of autologous serum and RA application in patients with ocular surface diseases. Furthermore, the data suggest that MUC4 and -16 are particularly important hydrophilic molecules involved in maintenance of a healthy ocular surface.
Sense of Place in the Workplace: The Relationship Between Personal Objects and Job Satisfaction and Motivation

This study explored the nature of sense of place and how it might function for the workplace, developed and tested a survey instrument to measure sense of place in the workplace, and determined what relationship existed between that sense of place and the level of job satisfaction and motivation. Desk-bound employees completed a questionnaire recording opinions, attitudes, and physical characteristics of their workplaces and themselves. Descriptive features of the work places were recorded as frequencies. Sense of place was operationalized to include comfort, control, noise, privacy, and personalization in the workplace. Social interaction, time spent at work, sense of place, and motivation were identified as intervening variables. Job satisfaction was the dependent variable. The data was collapsed by factor analysis, indexes were formed, and correlations calculated within and between indexes. Employees who displayed work-related objects were positively correlated to motivation. Positive correlations between job satisfaction and motivation were demonstrated by display of personal objects and the ability to choose and arrange work area furnishings. Sense of place is an amorphous concept that can be adapted to interior settings. It can be measured by combining a variety of factors in the workplace. Because sense of place in the workplace is significantly related to job satisfaction and motivation, designers and their clients must evaluate the impact of allowing the employee to establish sense of place in the workplace.
A theory of the K-M mixing angles, and weak and strong CP

Abstract We present a model in which the quark mass matrices are of the symmetric Fritzsch form with the two physically relevant phases σ=τ= ±π 2 . The model explains all of the known aspects of the weak phenomenology of the K-M matrix including the strength of the weak CP violation. The model solves the strong CP problem by the Peccei-Quinn mechanism while the phases σ=τ= ±π 2 are generated by spontaneous symmetry breaking. The invisibility of the axion is more natural than in previous models. A possible direction for a more refined model is suggested.
An investigation into low dose blend uniformity and segregation determination using NIR spectroscopy

The objective of this research is to develop and implement a technique to monitor content uniformity of low dose, dry powder blends on-line with process analytical technology (PAT), and to provide an insight into the fundamental mechanisms of dry powder blending and segregation. In this study, systems were identified to ensure the detection and differentiation of various phenomena: segregation and homogeneity potential. Thus, four binary blend mixtures of various concentrations were prepared by varying particle: size, texture, density and friction. Conditions for segregation have been determined in the drum blender. Rotational speed of the blender was found to greatly affect the blending, having a significant effect on segregation. Some speeds promote segregation while others promote mixing or change the mode of segregation. Axial segregation was promoted for some speeds but disappeared for others. This mode of segregation is related to the difference between the angles of repose of the two powders at the speeds which favor segregation. The most obvious physical difference between the segregating powders was the median particle size.
Mast cells and their role in urticaria.

Mast cells are the primary effector cell type in urticaria and angioedema. Recognition of different types of mast cells has increased the understanding of their cell biology and may help refine the therapy of human allergic diseases. Mast cells containing chymase and tryptase (MC TC ) and tryptase alone (MC T ) are two distinct types distinguished on the basis of the neutral protease composition of their granules. MC T cells are distributed primarily in the lung and gastrointestinal mucosa, whereas MC TC cells lie primarily in skin and gastrointestinal submucosa. The appearance of MC T cells in intestinal tissue is T-lymphocyte dependent, whereas MC TC cells is not. The granules in unstimulated mature MC T cells typically contain complete scrolls, whereas those of MC TC cells often contain grating or lattice substructures. Major categories for the mediators of mast cells include preformed mediators present in the secretory granule, newly generated lipid-derived mediators, and cytokines.
Scavenging of Reactive Oxygen Species by a Glycolipid Fraction of Mycobacterium avium Serovar 2

Previous experiments indicated that MIF-A3, a peptidoglycolipid extracted from Mycobacterium avium serovar 2 (Mycobacterium paratuberculosis 18), inhibits the killing of Candida albicans by activated bovine peripheral blood-derived macrophages and murine thioglycollate-elicited peritoneal macrophages in vitro. Subsequent in vitro data from our laboratory indicated that this reduction in killing may be related to the ability of MIF-A3 to scavenge reactive oxygen species (ROS). In this study we examined this hypothesis directly by determining if MIF-A3 reduced exogenous H2O2-induced candidacidal activity. When Candida albicans was incubated with H2O2 (4 mM) alone, colony-forming units/ml x 10(4) (CFU/ml) were 0.4 +/- 0.1 (mean +/- SE, n = 4) as compared to 11.3 +/- 2.0 CFU/ml in control (untreated) cultures (p or = 6.8 U/ml, completely blocked the fungicidal effect of H2O2. However, reducing the amount of catalase from 6.8 U/ml to 3.4 U/ml resulted in a loss of scavenging activity, which was associated with a 50% increase in H2O2-mediated killing. Substituting MIF-A3 (400 micrograms/ml) for catalase, also reduced H2O2-induced fungicidal activity. In the absence of MIF-A3, H2O2 reduced Candida albicans to less than 10(3) CFU/ml. However, in the presence of MIF-A3 the CFU/ml of Candida albicans increased 7.5-fold. Based on concentration-response curves of H2O2 inhibition vs. increasing amounts of catalase we determined that the relative inhibitory capacity of the MIF-A3 (400 micrograms/ml) was approximately 1.0 U/ml "catalase equivalents." These findings provide direct evidence that MIF-A3 can scavenge H2O2, and reduce H2O2-induced killing of Candida albicans.
Politics and the rescue of insolvent savings and loans before 1989

The results presented in this paper are consistent with those predicted by public choice economists who believe that regulatory agencies represent the interests of their controlling congressional committees. Membership on committees is not random; congressmen seek committee assignments where they can represent the interests of their constituency. Congressmen from states where financial institutions are significant will seek membership on their respective banking committees. Once on those committees, congressmen will seek to protect and promote their own constituency. In the case of the savings and loan industry, insolvent savings and loans received benefits from staying in operation. These savings and loans gained another chance to gamble for resurrection. Being shut-down or placed in a management consignment program did not give this option. The results presented in our paper indicate that participation in one of the rescue programs is not random. Savings and loans in states with political power (representation on the Senate banking committee) are less likely to be resolved.
Preference-neutral attribute weights in the journal-ranking problem

A linear programming model is proposed for assigning linear attribute weights in the journal-ranking problem. The constraints in the model are derived solely from any quasi-dominance relations that can be established between the journals. The objective function of the model minimizes the maximum difference between the implied valuations for the pair of journals that define a constraint. In the sense that personal inputs are not introduced, the derived weights are preference neutral. The feasibility of the procedure is demonstrated for two sets of data. By considering various random samples of journals from the larger data set, it is shown that large differences can emerge in the attribute weights and in the journal rankings from different samples of journals, even when the sample sizes are large relative to the population size.
Perceptions of Men With Moderate to Severe Hemophilia Regarding the Management of Their Chronic Disorder and Utilization of Community-Based Support.

Hemophilia is a genetic bleeding disorder that almost exclusively affects men. There is a nationwide network of nonprofit organizations providing support to men with hemophilia, which are affiliate...
Effects of noise on optimal deconvolution accuracy in microwave observations

Due to large footprints of remotely sensed microwave brightness temperatures, accuracy of microwave observations in areas of large surface heterogeneity has always been a technological challenge. Microwave observations in areas dominated by waterbodies typically exhibit observed brightness temperature several tens of kelvins lower than areas having no surface water. The non-linearity between brightness temperature and other geophysical quantities such as soil moisture makes the accuracy of microwave observations a critical element for accurate estimation of these quantities. In retrieving soil moisture estimates, an error of 1 K in remotely sensed microwave brightness temperatures results in about 0.5–1% error in volumetric soil moisture. Large uncertainties in the observed brightness temperatures make such observations unusable in areas of large brightness temperature contrast. In this article, we discuss a deconvolution method to improve accuracy using the overlap in the adjacent microwave observations. We have shown that the method results in improved accuracy of 40% in brightness temperature estimation in regions of high brightness temperature contrast.
INCREASED INCIDENCE OF TESTICULAR CANCER IN MEN PRESENTING WITH INFERTILITY AND ABNORMAL SEMEN ANALYSIS

ABSTRACTPurpose:: We determined the standardized incidence ratio of testicular cancer in infertile men presenting with an abnormal semen analysis compared to the general population.Materials and Methods:: The charts from more than 3,800 men presenting with infertility and abnormal semen analysis during a 10-year period were retrospectively reviewed. The incidence of testicular tumors diagnosed in this group was compared to that of race and age matched controls during the same period from the general population (as reported by the Surveillance, Epidemiology and End Results [SEER] database).Results:: Of 3,847 men 10 (0.3%) with infertility and abnormal semen analysis were diagnosed with testicular tumors. Mean patient age was 32.6 years (range 25 to 52) and all 10 men were diagnosed with a seminomatous germ cell tumor. Two men had a history of cryptorchidism while the remaining 8 had no identifiable risk factors for testicular cancer. The SEER database reported an incidence of 10.6 cases of testicular cance...
Sister chromatid exchange analysis in cultured primary lung, liver, and kidney cells of mice following in vivo exposure to vinyl carbamate

Methods are described for the short-term culture (48 to 56 h) of lung, liver, and kidney cells from C57B1/6 mice. With these techniques, mice can be exposed in vivo to test compounds and the cells grown on cover glasses in the presence of 5-bromo-2′-deoxyuridine (BrdUrd) (5 μM) for analysis of sister chromatid exchange (SCE) and cell cycle kinetics. Mice exposed to vinyl carbamate (VC) ((10 to 60 mg/kg) by i.p. injection were used in the initial examination of this system. Cultured lung and kidney cells from epxosed animals (60 mg/kg) exhibited significant increases in SCE frequencies (approximately 3 to 5 times baseline); however, liver cells were much less responsive and showed less than a twofold increase over baseline SCE levels. Lung cultures initiated as long as 320 h after VC exposure (60 mg/kg) revealed a persistance of lesions leading to the formation of SCEs in vitro. This methodology permits analysis of cytogenetic damage in organs with very low mitotic activity after in vivo exposure to known or suspected genotoxicants.
Metabolism and function of platelet-activating factor in fetal rabbit lung development.

Abstract Previously, platelet-activating factor (PAF, PAF-acether, 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine) had been identified in association with a lamellar-body-enriched fraction of human amniotic fluid obtained from women in labor. In consideration of the fact that fetal lung is the source of lamellar bodies, we have investigated the capacity of the developing lung to synthesize PAF. The specific activity of the PAF biosynthetic enzyme, 1-alkyl-2-lyso-sn-glycero-3-phosphocholine:acetyl-CoA acetyltransferase, increased from 116 pmol/min per mg protein in day 21 fetal rabbit lung to 332 pmol/min per mg protein by day 31. Although this enzymatic activity in fetal kidney also increased, it never reached the level found in lung. In contrast, the acetyltransferase activity decreased by 80% in fetal liver between days 21 and 31. The acetyltransferase activity in lung was primarily localized in the microsomal fraction (105 000 × g pellet); however a significant proportion of the activity was found in the 18 000 × g pellet. The specific activity of acetyltransferase in adult alveolar type II rat pneumonocytes was significantly higher than that of adult rat lung or rat alveolar macrophages, suggesting that type II cells make a significant contribution to the acetyltransferase activity of lung tissue. PAF acetylhydrolase remained relatively constant throughout the gestation in all tissues. The concentration of PAF in the fetal lung increased by 3-fold from 12 to 35 fmol/mg protein, between day 21 and day 31 of development. The concentrations of the PAF precursors, 2-lyso-PAF (1-alkyl-2-lyso-sn-glycero-3-phosphocholine) and the 2-acyl derivative, were several orders of magnitude higher than the PAF concentration. The pulmonary glycogen content decreased from 163 at day 21 to 35 μg/mg protein at day 31 of gestation. We suggest that the increase in PAF concentration may participate in the regulation of glycogen breakdown in fetal lung as it does in perfused rat liver (Shukla, S.D., Buxton, D.B., Olson, M.S. and Hanahan, D.J. (1983) J. Biol. Chem. 258, 10212–10214). The formation of PAF in the developing lung and its secretion, in association with lamellar bodies, into amniotic fluid is discussed in relation to parturition.
Isolating the benefits of fluid restriction in patients with heart failure: A pilot study.

Background:Fluid restriction (FR) in persons with heart failure (HF) is often prescribed, yet self-regulation and the troublesome symptom of thirst are difficult for patients to manage.Aims:The purpose of this pilot study was to test an educational and behavioral intervention (EBI) on adherence with prescribed FR and outcome measures of fluid congestion, symptom distress, and health related quality of life (HRQL). Secondary aims were to describe the relationships between self-reported and objectively measured determinants of fluid status and symptoms, and assess the psychometric properties of piloted instruments, and intervention effect sizes.Methods:NYHA Class II-IV (n=25, 44-83 years, 56% male, 20% minority, mean EF 23.0+11.7%) participants were randomized to the EBI or attention control (AC) and evaluated at baseline, 3 and 6 months.Results:EBI patients trended toward decreasing fluid ingestion (p=0.08), experienced less HF symptom frequency (p=0.13) and severity (p=0.06), and increased symptoms of thi...
Geometry of interpolation sets in derivative free optimization

We consider derivative free methods based on sampling approaches for nonlinear optimization problems where derivatives of the objective function are not available and cannot be directly approximated. We show how the bounds on the error between an interpolating polynomial and the true function can be used in the convergence theory of derivative free sampling methods. These bounds involve a constant that reflects the quality of the interpolation set. The main task of such a derivative free algorithm is to maintain an interpolation sampling set so that this constant remains small, and at least uniformly bounded. This constant is often described through the basis of Lagrange polynomials associated with the interpolation set. We provide an alternative, more intuitive, definition for this concept and show how this constant is related to the condition number of a certain matrix. This relation enables us to provide a range of algorithms whilst maintaining the interpolation set so that this condition number or the geometry constant remain uniformly bounded. We also derive bounds on the error between the model and the function and between their derivatives, directly in terms of this condition number and of this geometry constant.
The development of the premandibular head cavities and the relations of the anterior end of the notochord in the chick and robin

The prochordal plate in the chick is a thickening of the entoderm in the anterior part of the area pellucida. It consists at first of several layers of yolk-charged cells, which finally lose their yolk and form a thin layer of entoderm. The prechordal plate (an area of mesodermal proliferation immediately anterior to the notochord) arises immediately anterior to the primitive streak (and head process when the latter appears) in a part of the region once occupied by the prochordal plate. Later the prechordal plate comes to lie upon the dorsal wall of the foregut. The premandibular cavities arise in condensations of the prechordal mesoderm. The cavities seem to appear during the rapid expansion of the prechordal mesoderm which occurs in response to a release from constraint imposed by surrounding structures. They are connected with one another across the midline by a usually solid bridge of mesoderm. Later, the cavities are replaced by a mesodermal condensation which serves as a mold, on the surface of which the oculomotor muscles appear, arising before the disappearance of the premandibular head cavities. Differences in the relations of notochord and hypophysis in the chick and robin may be explained by an analysis of the growth of the two forms. The analysis furnishes a basis for understanding the relations of the anterior end of the notochord in the mammal.
Fundamental design tradeoffs in cognitive radio systems

Under the current system of spectrum allocation, rigid partitioning has resulted in vastly underutilized spectrum bands, even in urban locales. Cognitive radios have been proposed as a way to reuse this underutilized spectrum in an opportunistic manner. To achieve this reuse while guaranteeing non-interference with the primary user, cognitive radios must detect very weak primary signals. However, uncertainties in the noise+interference impose a limit on how low of a primary signal can be robustly detected.In this paper, we show that the presence/absence of possible interference from other opportunistic spectrum users represents a major component of the uncertainty limiting the ability of a cognitive radio network to reclaim a band for its use. Coordination among nearby cognitive radios is required to control this uncertainty. While this coordination can take a form similar to a traditional MAC protocol for data communication, its role is different in that it aims to reduce the uncertainty about interference rather than just reducing the interference itself.We show how the degree of coordination required can vary based on the coherence times and bandwidths involved, as well as the complexity of the detectors themselves. The simplest sensing strategies end up needing the most coordination, while more complex strategies involving adaptive coherent processing and interference prediction can be individually more robust and thereby reduce the need for coordination across different networks. We also show the existence of a coordination radius wall which limits secondary user densities that can be supported irrespective of coordination involved. Furthermore, local cooperation among cognitive radios for collective decision making can reduce the fading margins we need to budget for. This cooperation benefits from increased secondary user densities and hence induces a minima in the power-coordination tradeoff.
Comparing the Context of Immigrant Homicides in Miami: Haitians, Jamaicans and Mariels

We contribute to the field of immigration and crime research by conducting one of the first contemporary examinations of Afro-Caribbean homicides. Despite the growth of immigration across urban Ame...
ATP citrate lyase is an important component of cell growth and transformation

Cell proliferation requires a constant supply of lipids and lipid precursors to fuel membrane biogenesis and protein modification. Cytokine stimulation of hematopoietic cells directly stimulates glucose utilization in excess of bioenergetic demand, resulting in a shift from oxidative to glycolytic metabolism. A potential benefit of this form of metabolism is the channeling of glucose into biosynthetic pathways. Here we report that glucose supports de novo lipid synthesis in growing hematopoietic cells in a manner regulated by cytokine availability and the PI 3 K/Akt signaling pathway. The net conversion of glucose to lipid is dependent on the ability of cells to produce cytosolic acetyl CoA from mitochondria-derived citrate through the action of ATP citrate lyase (ACL). Stable knockdown of ACL leads to a significant impairment of glucose-dependent lipid synthesis and an elevation of mitochondrial membrane potential. Cells with ACL knockdown display decreased cytokine-stimulated cell proliferation. In contrast, these cells resist cell death induced by either cytokine or glucose withdrawal. However, ACL knockdown significantly impairs Akt-mediated tumorigenesis in vivo. These data suggest that enzymes involved in the conversion of glucose to lipid may be targets for the treatment of pathologic cell growth.
Properties of sustained release hot-melt extruded tablets containing chitosan and xanthan gum.

Abstract The aim of this study was to investigate the influence of pH, buffer species and ionic strength on the release mechanism of chlorpheniramine maleate (CPM) from matrix tablets containing chitosan and xanthan gum prepared by a hot-melt extrusion process. Drug release from hot-melt extruded (HME) tablets containing either chitosan or xanthan gum was pH and buffer species dependent and the release mechanisms were controlled by the solubility and ionic properties of the polymers. All directly compressed (DC) tablets prepared in this study also exhibited pH and buffer species dependent release. In contrast, the HME tablets containing both chitosan and xanthan gum exhibited pH and buffer species independent sustained release. When placed in 0.1N HCl, the HME tablets formed a hydrogel that functioned to retard drug release in subsequent pH 6.8 and 7.4 phosphate buffers even when media contained high ionic strength, whereas tablets without chitosan did not form a hydrogel to retard drug release in 0.1N HCl. The HME tablets containing both chitosan and xanthan gum showed no significant change in drug release rate when stored at 40 °C for 1 month, 40 °C and 75% relative humidity (40 °C/75% RH) for 1 month, and 60 °C for 15 days.
Reverse Water Flow in Sorghum Roots

Efflux of water from plant roots has implications for nutrient uptake in dry soil, the effectiveness of collection of water from deep in the soil, water parasitism among plants, and the ability of roots to resume water uptake after exposure to dry soil. We measured the minimum soil water potential required for reverse flow in sorghum [Sorghum bicolor (L.) Moench], the diurnal time-course of the efflux, and differences between sorghum genotypes in reverse flow. A splitroot system was used in which near-surface roots were subjected to drying and deeper roots were in free water. Efflux of water to the dry soil could first be detected at a soil water potential of about -0.55 MPa, or across a soil water potential gradient of 0.55 MPa, a smaller value than previously reported to induce reverse flow [...]
Alcohol-assisted growth of copper CVD films

Abstract We report the effect of various alcohols on the transport mechanism and reaction kinetics of Cu(hfac) 2 reduction for copper CVD. A variety of transport experiments are performed, all of which indicate that the presence of alcohol does nothing to increase the vapor phase transport rate of Cu(hfac) 2 . In contrast, steady-state kinetic measurements reveal a significant increase in CVD growth rates upon addition of an alcohol co-reactant, which we therefore attribute to an alcohol-assisted enhancement of the intrinsic kinetics of Cu(hfac) 2 reduction. For the series of alcohols studied, the enhancement factor increases in the order: MeOH i -PrOH; this correlates with the p K a values of the alcohols. The dependence of the growth rate on alcohol partial pressure is first-order, which can be described using a simple modification of our earlier Langmuir–Hinshelwood rate expression for H 2 reduction of Cu(hfac) 2 . The revised expression is consistent with a mechanism in which the rate limiting step involves H + transfer between an adsorbed alcohol molecule and the first dissociated (hfac) ligand from an adsorbed Cu(hfac) 2 molecule.
Nanoencapsulation Method for High Selectivity Sensing of Hydrogen Peroxide inside Live Cells

Reactive oxygen species (ROS) are ubiquitous in life and death processes of cells (Finkel, T.; Holbrook, N. J. Nature 2000, 408 (6809), 239−247), with a major role played by the most stable ROS, hydrogen peroxide (H2O2). However, the study of H2O2 in live cells has been hampered by the absence of selective probes. Described here is a novel nanoprobe (“nanoPEBBLE”) with dramatically improved H2O2 selectivity. The traditional molecular probe, 2′,7′-dichlorofluorescin (DCFH), which is also sensitive to most other ROS, was empowered with high selectivity by a nanomatrix that blocks the interference from all other ROS (hydroxyl radical, superoxide, nitric oxide, peroxynitrite, hypochlorous acid, and alkylperoxyl radical), as well as from enzymes such as peroxidases. The blocking is based on the combination of multiple exclusion principles: time barrier, hydrophobic energy barrier, and size barrier. However, H2O2 sensitivity is maintained down to low nanomolar concentrations. The surface of the nanoprobe was en...
A Diagnostic Classification Model for Document Processing Skills.

Abstract : This paper introduces a modification to the Rule Space diagnostic classification procedure which allows for processing of response vectors containing missing data. Rule Space is an approach to diagnostic classification which involves characterizing examinees' performances in terms of an underlying cognitive model of generalized problem-solving skills. It has two components: (1) a procedure for determining a comprehensive set of knowledge states, where each state is characterized in terms of a unique subset of mastered skills; and (2) a procedure for classifying examinees into one or another of the specified states. The procedure for determining a comprehensive set of knowledge states is based on the Boolean descriptive function given in Tatsuoka (1991). The procedure for classifying examinees involves comparing examinees' scored response vectors to the patterns expected within each of the specified knowledge states. Missing data is expected to be a common problem for this approach because, although the procedure for determining the comprehensive set of knowledge states requires a large pool of items, the procedure for examinee classification can be performed with smaller (less expensive) item subsets. This approach to diagnostic classification is illustrated with data collected in the Survey of Young Adult Literacy, a nationwide survey of literacy skills conducted by the National Assessment of Educational Progress (NAEP) in 1985.
REBIVE: a reliable private data aggregation scheme for wireless sensor networks

An important topic addressed by the wireless sensor networks community over the last several years is the in-net work data aggregation. It is significant as well as a challenging issue to provide reliable data aggregation scheme while preserving data privacy. However, in WSNs, achieving ideal data accuracy is complicated due to collision, heavy network traffic, processing delays and/or several attacks. The problem of gathering accurate integrated data will be further intensified if the environment is adverse. Hence how to attain data privacy and perfect data accuracy are two major challenges for data aggregation in wireless sensor networks. To address this problem, we propose in this paper a new privacy preserving data aggregation scheme. We present REBIVE (REliaBle prIVate data aggregation scheme). In REBIVE the data accuracy maintenance and data privacy protection mechanisms work cooperatively. Different from past research, our proposed solution have the following features: providing privacy preservation technique for individual sensor data and aggregated sensor data; maintaining perfect data accuracy for realistic environments; being highly efficient; and being robust to popular attacks launched in WSNs.
Contrast gain control in psychophysical contrast discrimination

Contrast masking may in part reflect the operation of contrast gain control mechanisms in the visual system. Four experiments were conducted in order to examine contrast discrimination under conditions in which the base contrast was interrupted with various maskers. Interrupting the base contrast grating at 8 Hz—with a uniform field, with a randomly phase-shifted version of the same grating, or with a higher contrast version of the same grating—interfered with contrast discrimination. These effects occurred only when the background contrast was above its own threshold. These results may be explained by assuming that the networks responsible for contrast gain control operate by temporally averaging contrast over a period greater than 62.5 msec. When this time-averaged contrast is different from the base contrast, contrast discrimination suffers.
Three-dimensional optical tomographic brain imaging in small animals, part 2: Unilateral carotid occlusion

This is the second part of a two-part study that explores the feasibility of 3-D, volumetric brain imaging in small animals by opti- cal tomographic techniques. In part 1, we demonstrated the ability to visualize global hemodynamic changes in the rat head in response to elevated levels of CO2 using a continuous-wave instrument and model-based iterative image reconstruction (MOBIIR) algorithm. Now we focus on lateralized, monohemispherically localized hemody- namic effects generated by unilateral common carotid artery (CCA) occlusion. This illustrates the capability of our optical tomographic system to localize and distinguish hemodynamic responses in differ- ent parts of the brain. Unilateral carotid occlusions are performed in ten rodents under two experimental conditions. In the first set of ex- periments the normal systemic blood pressure is lowered to 50 mmHg, and on unilateral carotid occlusion, we observe an ipsilateral monohemispheric global decrease in blood volume and oxygenation. This finding is consistent with the known physiologic response to ce- rebral ischemia. In a second set of experiments designed to observe the spatial-temporal dynamics of CCA occlusion at normotensive blood pressure, more complex phenomena are observed. We find three different types of responses, which can be categorized as com- pensation, overcompensation, and noncompensation. © 2004 Society of
Progression analysis and stage discovery in continuous physiological processes using image computing

We propose an image computing-based method for quantitative analysis of continuous physiological processes that can be sensed by medical imaging and demonstrate its application to the analysis of morphological alterations of the bone structure, which correlate with the progression of osteoarthritis (OA). The purpose of the analysis is to quantitatively estimate OA progression in a fashion that can assist in understanding the pathophysiology of the disease. Ultimately, the texture analysis will be able to provide an alternative OA scoring method, which can potentially reflect the progression of the disease in a more direct fashion compared to the existing clinically utilized classification schemes based on radiology. This method can be useful not just for studying the nature of OA, but also for developing and testing the effect of drugs and treatments. While in this paper we demonstrate the application of the method to osteoarthritis, its generality makes it suitable for the analysis of other progressive clinical conditions that can be diagnosed and prognosed by using medical imaging.
Sustained poststimulus elevation in cerebral oxygen utilization after vascular recovery

The brain's response to functional activation is characterized by focal increases in cerebral blood flow. It is generally assumed that this hyperemia is a direct response to the energy demands of activation, the so-called flow-metabolism coupling. Here we report experimental evidence that increases in oxygen metabolism can occur after activation without increases in flow. When using multimodality functional MRI (fMRI) to study visual activation in human brain, we observed a postactivation period of about 30 seconds during which oxygen consumption remained elevated, while blood flow and volume had already returned to baseline levels. The finding of such a prolonged and complete dissociation of vascular response and energy metabolism during the poststimulus period indicates that increased metabolic demand needs not per se cause a concomitant increase in blood flow. The results also show that the postactivation undershoot after the positive blood-oxygen-level-dependent hemodynamic response in fMRI should be reinterpreted as a continued elevation of oxygen metabolism, rather than a delayed blood volume compliance.
Sexuar las diferencias

Este ensayo interpreta y elabora la metafora de la danza, utilizada por Derrida en sus respuestas a los cuestionamientos acerca de los feminismos que le hace McDonald en “Coreografias”, el famoso dialogo entre ambos. La imagen de la danza es el medio para construir la propuesta derridiana de la diferencia sexual.
Generalized theory of neutron scattering from hydrogen in metals

A recent analysis by the author of inelastic scattering of neutrons from dilute hydrogen in metals in terms of coherent itinerant-proton energy bands is generalized to include incoherent processes such as the spontaneous decay of the proton from excited-oscillator states to the ground state, as well as incoherent hopping among excited local-oscillator states centered at neighboring interstitial occupancy sites. Similarly, the analysis of Chudley and Elliott of quasielastic neutron scattering and its extension by Rowe, Sk\"old, Flowtow, and Rush are generalized to include coherent hopping (band transport) in the self-correlation function describing motion of the proton among neighboring oscillator ground states (and, when applicable, among excited states). The general formalism developed here encompasses quasielastic and inelastic scattering and allows for the coexistence of coherent and incoherent processes. At each level of complexity, the expressions obtained for the cross sections are shown to reduce to earlier results in the limits when either the coherent or the incoherent contributions to the neutron bandwidths can be ignored.
Bridging the Trade-Environment Divide

Protection. For free traders, this word represents the consummate evil. For environmentalists, it is the ultimate good. Of course, for the trade community, “protection” conjures up dark images of Smoot and Hawley, while the environmental camp sees clear mountain streams, lush green forests, and piercing blue skies. One cannot blame all of the tensions at the trade-environment interface on linguistic differences, but these competing perspectives are emblematic of a deep clash of cultures, theories, and assumptions. Trade officials often seek to limit efforts to link trade and environmental policy-making, and sometimes to prohibit such efforts altogether. In this regard, the narrow focus and modest efforts of the World Trade Organization’s Committee on Trade and Environment are illustrative. 1 The launch of negotiations for a Free Trade Area of the Americas with an express decision to exclude environmental issues from the agenda provides an even starker example of the trade community’s hostility toward serious environmental engagement. Economists have been prominent among those arguing that pollution control and natural resource management issues are best kept out of the trade policy-making process (Cooper, 1994; Bhagwati, 1999). Other economists, however, have tried to set trade policy-making in a broader context and to build environmental sensitivity into the international trading system (Runge, 1994; Rodrik, 1997; Summers, 2000).
The single umbilical artery in a high-risk patient population: what should be offered?

Objective. To determine whether fetal echocardiography is warranted in cases of single umbilical artery in a population at risk for aneuploidy. Methods. All cases of fetal single umbilical artery identified over a 2-year period were reviewed for other sonographically detected abnormalities, fetal echocardiographic results, and karyotype. Results. Sixty-five cases of single umbilical artery were diagnosed on the basis of initial sonograms. Five were subsequently shown to have 3-vessel cords (8% false-positive diagnosis; incidence, 1.2 %). Excluding 3 from twin gestations, 57 cases formed the study population. Thirty-one fetuses (54%) were initially thought to have isolated single umbilical arteries, and 26 (46%) had nonisolated single umbilical arteries. Fetal echocardiography was performed in 29 cases (51%), 24 (83%) with normal findings and 5 (17%) with abnormal findings. Four (50%) of 8 nonisolated single umbilical arteries had abnormal echocardiographic findings versus 1 (5%) of 21 apparently isolated single umbilical arteries (P <.05; odds ratio, 20). Karyotypes in 36 cases (63%) showed 25 (69%) euploid and 11 (31%) aneuploid fetuses. An apparently isolated single umbilical artery was never associated with an abnormal karyotype. Eleven (50%) of 22 fetuses with nonisolated single umbilical arteries had aneuploidy (P <.005). The side of the missing umbilical artery did not correlate with other sonographically detected abnormalities, abnormal fetal echocardiographic findings, or aneuploidy. Condusions. The rate of cardiac malformations seen with apparently isolated single umbilical arteries is significant, and fetal echocardiography should be performed.