cssi/SciSciGPT-SciSciNet huggingface dataset:
Differential effects of zinc and magnesium ions on mineralization activity of phosphatidylserine calcium phosphate complexes

Mg(2+) and Zn(2+) are present in the mineral of matrix vesicles (MVs) and biological apatites, and are known to influence the onset and progression of mineral formation by amorphous calcium phosphate (ACP) and hydroxyapatite (HAP). However, neither has been studied systematically for its effect on mineral formation by phosphatidylserine-Ca(2+)-Pi complexes (PS-CPLX), an important constituent of the MV nucleation core. Presented here are studies on the effects of increasing levels of Mg(2+) and Zn(2+) on the process of mineral formation, either when present in synthetic cartilage lymph (SCL), or when incorporated during the formation of PS-CPLX. Pure HAP and PS-CPLX proved to be powerful nucleators, but ACP took much longer to induce mineral formation. In SCL, Mg(2+) and Zn(2+) had significantly different inhibitory effects on the onset and amount of mineral formation; HAP and PS-CPLX were less affected than ACP. Mg(2+) and Zn(2+) caused similar reductions in the rate and length of rapid mineral formation, but Zn(2+) was a more potent inhibitor on a molar basis. When incorporated into PS-CPLX, Mg(2+) and Zn(2+) caused significantly different effects than when present in SCL. Even low, subphysiological levels of Mg(2+) altered the inherent structure of PS-CPLX and markedly reduced its ability to induce and propagate mineral formation. Incorporated Zn(2+) caused significantly less effect, low (<20 microM) levels causing almost no inhibition. Levels of Zn(2+) present in MVs do not appear to inhibit their nucleational activity.
Bone marrow recurrence after initial intensive treatment for childhood acute lymphoblastic leukemia.

BACKGROUND The authors studied the clinical outcome of 106 children with acute lymphoblastic leukemia (ALL) who developed a bone marrow recurrence as the first adverse event after contemporary intensified therapy. METHODS Endpoints were the rates and lengths of second remission, the cumulative incidence of second hematologic recurrence, second event-free survival (EFS), and survival. RESULTS Bone marrow recurrences were isolated in 79 patients, and combined with an extramedullary site in 27 patients. The median time to recurrence was 2.6 years (range, 0.3–11.6 years). Seventy-six patients (71.7%) attained a second remission (median length, 0.7 year; range, 0.03–13.3 years). The 5-year survival probability among all patients was 24.2% ± 4.2% (standard error). On multivariate analysis, time to first disease recurrence and blast cell lineage were found to be independent predictors of a second EFS (P = 0.008 and P = 0.028, respectively). The 5-year EFS estimate in patients with an initial disease remission of ≥ 36 months was 42.6% ± 7.8% but was only 12.5% ± 3.9% among children with a short duration of disease remission (< 36 months). These estimates were 28.7% ± 4.9% and 5.0% ± 3.4%, respectively, for B blast and T blast cell lineages. CONCLUSIONS Despite acceptable long-term second EFS rates for certain subgroups, overall bone marrow recurrence after intensified first-line therapy for childhood ALL signals a poor outcome. Cancer 2005. © 2004 American Cancer Society.
Kinetics of Popping of Popcorn

ABSTRACT The rate of popping of popcorn was measured in oil and in air. Kinetic data for lifetimes of individual kernels from a large population were obtained in oil at six constant temperatures (180–250°C) and also in an air-popper at 202°C. The data are characterized by an induction period, which is, significantly, followed by a first-order decrease in the number of unpopped kernels versus time. The activation energy for the first order process is 166.7 kJ/mol between 180 and 210°C, and 53.8 kJ/mol between 210 and 250°C. These data are consistent with a model that assumes 1) that the rate of heat transfer into a kernel follows Newton's law of cooling; 2) that in a sample of kernels there exists a distribution of critical pressures; 3) that for an individual kernel, the probability of popping is directly proportional to the difference between the internal aqueous vapor pressure and the kernel's critical pressure; and 4) that the measured rate constant at any temperature is an average overall of the kerne...
Fibromatous epulis in dogs and peripheral odontogenic fibroma in human beings : two equivalent lesions

This article compares the clinical and histopathologic features of the peripheral odontogenic fibroma in human beings and the fibromatous epulis in dogs. They are apparently equivalent lesions. Both are odontogenic tumors of limited growth potential that do not recur if adequately excised; both occur in middle and late adulthood of the species concerned. The one difference is that the peripheral odontogenic fibroma is a rare condition, whereas the canine fibromatous epulis is common.
PLASTID INCLUSIONS IN EPIDERMAL CELLS OF BETA

Inclusions were found in epidermal plastids of Beta vulgaris L., by the use of the electron microscope. One type of inclusion resembles the membrane-bound plastid inclusions found by others in various meristematic plant cells; the other does not appear to have been described before. The second type of inclusion is not membrane-bound and appears elongated and fibrillar in longisection. The elongated plastid inclusion sometimes becomes quite large. It is postulated that Beta epidermal cells may store two different proteins under some conditions.
Stratification and paleocirculation of the Late Cretaceous Western Interior Seaway of North America

Paleotemperature and salinity profiles for the Western Interior Seaway are reconstructed by use of oxygen and carbon isotopic signatures of shell material. Data have been gathered on different groups of molluscs distributed in three distinct habitat types: infaunal benthonic, epifaunal benthonic, and nektonic. Isotopic variations and inferred environmental tolerances of the organisms were used to determine upper and lower temperature boundaries for each habitat group and therefore water-depth zones. Water density for each temperature-salinity combination within a habitat range was calculated and used to develop a physically stable stratification model. The results clearly show that the water column consisted of denser, more saline, warm bottom layers that were overlain by, and decoupled from, cooler, less saline intermediate layers. It is proposed that this profile originated due to a surface current transporting runoff water from the western highlands toward the eastern shallow border of the seaway where evaporation and heating of surface water in a warm, humid atmosphere caused increased density and sinking, followed by westward return flow of the warm saline bottom water. This model is compatible with known climatic and oceanographic information for the Cretaceous.
Degenerate cadmium oxide films for electronic devices

Highly conducting and transparent cadmium oxide films have been deposited on Corning 7059 glass substrates by ion-beam sputtering and by spray pyrolysis. The electrical and optical properties of CdO films prepared by the two techniques are similar. Typical films of 0.5 μm thickness have electrical resistivities of (2–5) × 10-3 ohm-cm, carrier concentrations of approximately 1020 cm-3, and an optical transmission of higher than 70% in the wavelength range of 600–900 nm. An optical bandgap of 2.4–2.42 eV was deduced from the optical transmission data.
Cultured neonatal rat oligodendrocytes are enriched in acid hydrolase activities.

We measured the activity of several acid hydrolases in oligodendrocyte and mixed glial (predominantly astrocytic) cell cultures prepared from neonatal rat cerebra. When compared with the mixed glial cultures, the cultured oligodendrocytes exhibited higher levels for all the hydrolases when activities were normalized to protein content. When enzymic activities were examined as a function of DNA content, oligodendrocytic α-l-fucosidase, β-d-glucuronidase, arylsulfatase, and N-acetyl-β-d-glucosaminidase were higher than in mixed glial cultures, whereas the activities of α-d-glucosidase, β-d-galactosidase and acid phosphatase were not elevated. These differences could not be accounted for by the fetal bovine serum present in the culture medium. The enrichment in acid hydrolase specific activities in the oligodendrocytes may be associated with a rapid turnover of at least some of the extensive myelin-like membranes formed by these cultured cells. Alternatively, the enrichment of acid hydrolase activity in the oligodendrocytes may be associated with intracellular vesicles of lysosomal origin which may play a role in myelin-like membrane assembly. Exactly which of the above two processes, or possible combinations thereof, is responsible for the present finding is not known.
Prenatal ethanol exposure alters sensitivity to the effects of apomorphine given alone and in combination with ethanol on locomotor activity in adult male mouse offspring

Previous studies have indicated that prenatal ethanol (EtOH) exposure alters developing catecholamine (CA) systems and acute sensitivity to the locomotor stimulant effects of EtOH. The purpose of this study was to examine whether prenatal EtOH exposure influences the effects of the direct dopamine (DA) agonist apomorphine given alone as well as in combination with a low-dose stimulant challenge of EtOH. Standard lab chow or liquid diets containing either 25% EtOH-derived calories (EDC), or 0% EDC were given to pregnant C3H/He mice on gestation days 6-18. At 90 days of age, male offspring from each prenatal treatment group were monitored for 10 min in an open field following IP injections of apomorphine (0, 0.15, 0.3, 0.6, or 1.2 mg/kg) and either EtOH (1.5 g/kg) or saline. EtOH alone increased activity by 120-143% in all three groups of offspring. In control offspring, apomorphine dose-dependently decreased activity up to 74%-78% and blocked the stimulant effect of EtOH at all doses tested. However, in prenatal EtOH-exposed offspring, higher doses of apomorphine were significantly less effective in reducing both baseline and EtOH-stimulated activity compared to control mice. This effect is most likely not due to differences in pharmacokinetics, because blood EtOH concentrations were similar across apomorphine doses and prenatal treatment conditions. As such, these results support the hypothesis that prenatal exposure to EtOH alters acute sensitivity to the locomotor stimulant effects of EtOH, particularly under conditions in which CA systems mediating those effects are additionally challenged. In addition, the results suggest that prenatal EtOH exposure results in a long-lasting perturbation of central DA receptor sensitivity.
Mechanisms underlying nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD), a spectrum of liver damage, encompasses steatosis, steatohepatitis, an intermediate stage of liver disease and cirrhosis. Although NAFLD is the leading cause of chronic liver disease, no effective therapies currently exist. Complex interactions between injury and repair mechanisms likely determine disease progression in NAFLD. The development of successful treatments for NAFLD can be facilitated by understanding disease mechanisms.
Spin dynamics of chromium. II. Incommensurate alloys

Since magnetic moments of transition-metal antiferromagnets are created by electron-hole pairs, the spin dynamics of Cr alloys are associated with quasiparticle transitions. This paper uses random-phase approximation to investigate spin dynamics about two different spin-density-wave (SDW) states of incommensurate ({ital I}) alloys with wave vectors {ital Q}{sub {+-}}{sup {prime}}=(2{pi}/{ital a})(0,0,1{+-} {partial_derivative} {prime}). Because of the more complex quasiparticle energies, {ital I} alloys have a richer spectrum of collective excitations than the commensurate ({ital C}) alloys studied previously. Associated with the free energy`s rotational invariance are transverse spin-wave (SW) modes which evolve from each satellite wave vector {ital Q}{sub {+-}}{sup {prime}} with the same temperature-independent mode velocity {ital c}={ital v}{sub {ital F}}/{radical}(3) as in the {ital C} regime. The translational invariance of the ISDW state is responsible for longitudinal phason modes which evolve from the satellite wave vectors and are damped for any nonzero frequency. As {ital T}{r_arrow}{ital T}{sub {ital N}}, the phason mode velocity approaches {ital c}. Together with a related longitudinal damped excitation, the phason modes tilt the SW cones towards {bold G}/2=(2{pi}/{ital a}) (0,0,1) and produce a peak in the {bold G}/2 cross section at 60 meV, as observed experimentally. High-frequency amplitude modes, both transverse and longitudinal, liemore » near the pair-breaking edge for each satellite, which is about 40{percent} lower than in the {ital C} case. Undamped collective modes called wavons are associated with fluctuations of the SDW wave vectors {ital Q}{sub {plus_minus}}{sup {prime}} about their equilibrium values. Wavon modes were recently observed as peaks in the satellite cross sections between 15 and 20 meV. Our model predicts the temperature and doping dependences of the phason and wavon peaks. {copyright} {ital 1996 The American Physical Society.}« less
A note on the absorption of 3-methoxy-N-methyl-morphinan hydrochloride from the rat stomach

(+)-3-Methoxy-N-methylmorphinan, a base with a pKa of 7·97 is absorbed from the rat stomach at pH 2·0, in a manner which suggests passive diffusion rather than a specialized transport process to be the mechanism.
Life satisfaction, fear of death, and ego identity in elderly adults

Erikson’s eighth developmental stage, ego integrity vs. despair, was examined using the Life Satisfaction Index-A (LSIA) as a measure of ego integrity, the Death Anxiety Scale (DAS) as a measure of despair, and the Ego Identity Scale (EIS) as a measure of the successful resolution of the first six stages of psychosocial development. Three hypotheses were tested: (1) A positive correlation would exist for performance on the LSIA and the EIS, (2) a negative correlation would exist for performance on the DAS and on the LSIA, and (3) a negative correlation would exist for performance on the DAS and on the EIS. The subjects were 100 men and women 61-89 years of age. The first hypothesis was supported, and the second and third were supported with men but not with women.
Sexual risk and HIV infection among drug users in New York City: a pilot study.

Measures of sexual health were assessed during 2008–2009 in a New York City sample of 102 injection and noninjection users of heroin, cocaine, or crack. There was considerable overlap and transitioning between crack smoking and injecting. Crack users were also significantly more likely to be gay, lesbian, or bisexual than other drug users. In multivariate analysis, HIV infection was independently associated with crack use and with being gay or bisexual. In New York City, HIV prevention for drug users has focused on syringe access, safe injection, and drug user treatment, but further progress in HIV control will require strategies to address sexual health among people who use drugs. The study's limitations are noted.
Cyclic ADP-ribose induced Ca2+ release in rabbit skeletal muscle sarcoplasmic reticulum.

Abstract The Ca2+-mobilizing metabolite cyclic ADP-ribose (cADPR) has been shown to release Ca2+ from ryanodine-sensitive stores in many cells. We show that this metabolite at a concentration of 17μM, but not its precursor β-NAD+ nor non-cyclic ADPR at the same concentration, is active in releasing Ca2+ from rabbit skeletal muscle sarcoplasmic reticulum. The release was not sensitive to Ruthenium red (1μM) nor to the ryanodine receptor-specific scorpion toxin Buthotus1-1 (10 μM). In planar bilayer single channel recordings, concentrations up to 50μM cADPR did not increase the open probability of Ruthenium red and toxin-sensitive Ca2+ release channels. Thus Ca2+ release induced by cADPR in skeletal muscle sarcoplasmic reticulum may not involve opening of ryanodine receptors.
Antifungal Activity of Artemisinin Derivatives

A series of 29 artemisinin derivatives (2-30), including four new compounds (16-18, 20), together with artemisinin (1), artemisinic acid (31), and arteannuin B (32), were tested for antifungal activity against two opportunistic pathogens, Candida albicans and Cryptoccocus neoformans. Of all the compounds tested, anhydrodihydro-artemisinin (3) demonstrated more potent antifungal activity against C. neoformans than amphotericin B. Also, beta-arteether (7) and alpha-arteether (8) showed marked activity against C. neoformans. Against C. albicans, the overall antifungal effect of these compounds was weak or negligible. Derivatives 2-30 were prepared according to literature procedures.
Multilevel fault tolerance in infrastructure-oriented wireless networks: framework and performance evaluation

Significant advances have been made in the design and implementation of dependable systems and networks over the last several years. However, many wireless networks have not been designed for highly dependable operation owing to network cost and complexity, and a lack of regulatory requirements on wireless service quality. One way to address this significant challenge is by introducing fault tolerance; however, very limited work has been done so far in the fault-tolerant design of wireless networks. In this paper, we address how to utilize fault tolerance in the design of infrastructure-oriented wireless networks. More specifically, an architectural design scheme is presented for multilevel fault tolerance using adaptable building blocks. The scheme utilizes 'selective' redundancy at component, link and block levels and a fault-tolerant architecture for interconnection of building blocks. The design scheme has been implemented in both analytical and simulation models. The detailed performance results show that fault tolerance at component, link, block, and interconnection levels can significantly improve the overall dependability performance. One interesting observation is that, to achieve highest dependability, fault tolerance at link, component or block level is not suffficient and must be combined with the interconnection level fault-tolerance.
From Metropolis to Never-neverland: Analyzing Fictional Characters in a Personality Theory Course

To enhance learning in a course on personality theories, students write four short papers, each interpreting the personality of a fictional character from a comic strip or children's story by using a specific theoretical orientation: psychoanalytic, dispositional, phenomenological, and behavioral. Advantages and other aspects of this technique are discussed, as are student evaluations.
Heat and oxygen flux as a function of environmental po2 in juvenile Australian crayfish, Cherax quadricarinatus

Oxygen and heat flux of the juvenile Australian red claw crayfish, Cherax quadricarinatus, were measured in parallel respirometry and calorimetry systems at 28°C at varying levels of environmental po2. Juvenile crayfish maintained an average oxygen flux of 5.0 ± 0.4 (SEM) pmol O2/(s*mg fresh weight) over the po2 range from 20.7 to 5 kPa. At approximately 4 kPa po2, oxygen flux decreased, conforming to decreasing oxygen tensions. Juvenile crayfish maintained an average heat flux of −2.2 ± 0.2 μW/mg fresh weight when exposed to 100 and 50% air saturated conditions (18.1 to 20.7 and 7.8 to 10.4kPa po2, respectively). The ratio of the amount of heat dissipated per oxygen consumed, called the calorimetric/respirometric (CR) ratio, at 100 and 50% air saturated conditions averaged −440 kJ/mol O2. When crayfish were exposed to 25% air saturated conditions (2.5 to 5.2 kPa po2), heat flux decreased initially to −1.1 ± 0.4 μW/mg fresh weight. Within 4 hr, however, heat flux returned to normoxic values. When crayfish were exposed to anoxic conditions, heat flux decreased to zero. Most juvenile crayfish did not survive short-term (1–2 hr) anoxic stress. These data suggest that juvenile C. quadricarinatus are excellent oxygen regulators over a wide range of environmental po2. These data indicate also that juvenile C. quadricarinatus can compensate metabolically, possibly via aerobic and/or anaerobic adjustments, in order to maintain metabolic rate at critically low po2. Last, this crayfish appears limited in its ability to utilize anaerobic pathways to maintain metabolic rate in anoxic environments. © Wiley-Liss, Inc.
Direct measurement of ground-state unimolecular decay rates in IR MPD of CF3I and C6F13I

Abstract Appearance rates of iodine atoms from infrared multiphoton dissociation of perfluoroalkyl iodides by clipped, SLM, CO2 laser pulses were measured as a function of intensity using multiphoton ionization detection. Intensity and fluence effects upon the internal energy of reacting molecules were assessed via RRKM theory and a simplified excitation model.
The Politics of Dissertation Advising: How Early Career Women Faculty Negotiate Access and Participation

Dissertation committees are complex social arenas that underscore expertise, image, and peer relationships—all of which affect professional identity and advancement. This study presents a sampling of how early career women faculty members learn about and negotiate their participation on dissertation committees. Research questions focused on participants’ concerns about the social and political aspects of participation viz a viz peer relationships and faculty rewards. We analyzed interview data using both holistic and constant comparative methods, resulting in a working model of active participation across three domains: knowledge, access, and membership. We also identified developmental trends of dissertation committee engagement across the early career.
Mad2 binding by phosphorylated kinetochores links error detection and checkpoint action in mitosis

Abstract The spindle checkpoint must detect the presence of unattached or improperly attached kinetochores and must then inhibit progression through the cell cycle until the offending condition is resolved. Detection probably involves attachment-sensitive kinetochore phosphorylation (reviewed in [1,2]). A key player in the checkpoint's response is the Mad2 protein, which prevents activation of the anaphase-promoting complex (APC) by the Cdc20 protein [3–8]. Microinjection of Mad2 antibodies results in premature anaphase onset [9,10], and excess Mad2 protein causes arrest in mitosis [5,11]. We have previously shown that Mad2 localizes to unattached kinetochores in vertebrate cells, and that this localization ceases as kinetochores accumulate microtubules [10,12,13]. But how is Mad2 binding limited to unattached kinetochores? Here, we used lysed PtK 1 cells to study kinetochore phosphorylation and Mad2 binding. We found that Mad2 binds to phosphorylated kinetochores, but not to unphosphorylated ones. Our data suggest that it is kinetochore protein phosphorylation that promotes Mad2 binding to unattached kinetochores. Thus, we have identified a probable molecular link between attachment-sensitive kinetochore phosphorylation and the inhibition of anaphase. The complete pathway for error control in mitosis can now be outlined.
Characterization of Vesicles by Classical Light Scattering

Abstract Classical, or static, light scattering techniques can be used to determine the geometric size, shape, apparent molecular weight, and radius of gyration of phosphatidylcholine vesicles in aqueous suspension. A Rayleigh-Gans-Debye (RGD) analysis of multiangle scattered light intensity data yields the size and degree of polydispersity of the vesicles in solution, while the Zimm plot technique provides the radius of gyration and apparent weight-average molecular weight. Together RGD theory and Zimm plots can be used to confirm the geometric shape of vesicles. Vesicles varying from 65 to 90 nm in diameter have been characterized effectively. The static light scattering measurements indicate that, as expected, phosphatidylcholine vesicles in this size range scatter light as isotropic hollow spheres. This dual treatment of the static light scattering data also provides an internal, self-consistent check of the vesicle size determination. The values for geometric radii determined by classical light scattering typically agree with those estimated by dynamic light scattering to within a few percent.
Quenching and disruption of lunar KREEP lava flows by impacts

The results of a reexamination of petrography of the Apollo 15 KREEP basalts are reported. Several of the basalts contain yellow residual glasses which cross-cut the crystallized phases; some show more extreme disruption. The features of the glasses appear to be compatible only with impact disruption, ejection, and quenching from actively crystallizing flows, indicating a high impact flux immediately after the impact that formed the Imbrium basin. No other example of impacts into active lava flows is known in the solar system.
Are anomalies in the kinetics of halogenation caused by hot atom effects ? An experimental investigation

Abstract It has been recently proposed that observed anomalies in the kinetic data base for the reaction of Cl with C2D6 may be explained by the formation of hot Cl atoms in the reactions C2H5 + Cl2 → C2H5Cl + Cl and C2D5 + Cl2 → C2D5Cl + Cl. We have performed a competitive kinetic study in which the loss of C2H6 and C2D6 were monitored following UV irradiation of C2H6C2D6Cl2N2 mixtures. A large excess of N2 diluent was used to ensure rapid thermalization of any hot Cl atoms formed in the system. Our measured value of κ(Cl + C2D6)/κ9Cl + C2H6) = 0.325 ± 0.020 is in agreement with results from previous relative rate studies in which no added N2 was used. This agreement shows that hot atom effects do not explain the anomalies in the literature values for the rate of the reaction Cl + C2D6.
Experimental and theoretical studies of electron binding energies for water adsorbed on α-alumina

Abstract Ultraviolet photoelectron spectra (HeI radiation) have been obtained for a partially hydroxylated surface of single crystal α-alumina (0001) and for water chemisorbed on this surface at 298 K. Model calculations using the SCF—Xα—SW method have also been performed and, with their aid, the features of the partially hydroxylated spectra have been assigned. Spectral features associated with additional hydration at 298 K are consistent with the adsorption of strongly bound molecular water.
Systematic effects in Kaon matrix elements calculations

Abstract During the last year, the RBC collaboration has generated an ensemble of lattices using the DBW2 gauge action, the domain wall fermion (DWF) action, 2 dynamical flavors of degenerate quarks, and three different dynamical quark masses with values of approximately 1 2 , 3 4 and 1 times the strange quark mass. With ∼ 4, 000 Hybrid Monte Carlo (HMC) trajectories for each dynamical mass on 163 × 32 lattices with LS = 12, we can begin to examine the matrix elements for the δS = 1 operators relevant to the δI = 1 2 rule and ϵ′/ϵ. Our statistics are too limited to quote physical values at this time; instead we compare the unrenormalized lattice matrix elements on these dynamical lattices with those from our earlier quenched lattices, which have a very similar lattice spacing, physical volume and range of quark masses.
Three Measurable and Modifiable Enteric Microbial Biotransformations Relevant to Cancer Prevention and Treatment

Interdisciplinary scientific evaluation of the human microbiota has identified three enteric microbial biotransformations of particular relevance for human health and well-being, especially cancer. Two biotransformations are counterproductive; one is productive. First, selective bacteria can reverse beneficial hepatic hydroxylation to produce toxic secondary bile acids, especially deoxycholic acid. Second, numerous bacterial species can reverse hepatic detoxification—in a sense, retoxify hormones and xeonobiotics—by deglucuronidation. Third, numerous enteric bacteria can effect a very positive biotransformation through the production of butyrate, a small chain fatty acid with anti-cancer activity. Each biotransformation is addressed in sequence for its relevance in representative gastrointestinal and extra-intestinal cancers. This is not a complete review of their connection with every type of cancer. The intent is to introduce the reader to clinically relevant microbial biochemistry plus the emerging evidence that links these to both carcinogenesis and treatment. Included is the evidence base to guide counseling for potentially helpful dietary adjustments.
Truncated RanGAP encoded by the Segregation Distorter locus of Drosophila.

Segregation Distorter (SD) inDrosophila melanogaster is a naturally occurring meiotic drive system in which the SD chromosome is transmitted fromSD/SD+ males in vast excess over its homolog owing to the induced dysfunction of SD+-bearing spermatids. The Sd locus is the key distorting gene responsible for this phenotype. A genomic fragment from theSd region conferred full distorting activity when introduced into the appropriate genetic background by germline transformation. The only functional product encoded by this fragment is a truncated version of the RanGAP nuclear transport protein. These results demonstrate that this mutant RanGAP is the functional Sd product.
Meiotic Protein in Spermatocytes of Mammals

THE DNA-binding protein in meiotic cells of Lilium1 has a very high binding affinity for single stranded DNA and also the unusual property of catalysing the renaturation of thermally denatured lily DNA at room temperature. Significantly, these and other in vitro properties are very similar to those of the “gene 32-protein” which is essential to genetic recombination in T4 bacteriophage2 and the possibility that this protein may have a function in meiotic recombination of Lilium led us to a more extensive study of its behaviour3.
Qatari Colloquial Arabic Quickly Changes Over Time

Languages are passed down through generations from parents to children by communication. Yet linguists find that languages (and varieties of languages) change over time - but at different rates. This study mainly aims at investigating semantic and word changes that took place in the Qatari colloquial Arabic over a period of thirty years. The research began by interviewing forty Qatari locals. The participants came from two age groups: (18-24 years) and (55-61 years) - this is to document change over time. The interview examined the presence of semantic changes in the Qatari colloquial Arabic. The linguistic variable in this study was a list of forty-five dialectical terms and expressions that were commonly used by adults 30 years ago. The second part of the research method included investigating the origin of each term from Kitab al-'Ayn (the first dictionary of the Arabic language) and Lisan Al Arab to confirm that they come from Arabic. The results of the research vary. The majority of the lexical items under investigation presented some form of change over the two generations; they showed phonetic, semantic as well as other types of change. There was also evidence of terms that were borrowed from languages such as Farsi, English and Urdo and incorporated into the Qatari local dialect, after undergoing phonetic change. Languages change for a variety of reasons. History reveals many examples of dialect change fuelled by migration/movement, colonization and economic growth. One finding of this research is that the vocabulary an individual uses nowadays is a social marker of age. An example of this includes the word ?????? )?ambalou?), meaning ambulance. This lexical item was borrowed from English before going through a phonological change, and users of this term tend to be from an older generation. The changes happening to the Qatari colloquial Arabic is an undocumented phenomenon. The study increases the awareness about the development of the language in the country and is a research platform for further investigation in the field.
Role of sulfhydryl oxidation in adipocyte plasma membrane surface in the response of adenylate cyclase to isoproterenol and glucagon.

Abstract When intact adipocytes of rat are briefly treated (5 min) with low concentrations (approx. K i of 5 · 10 −4 M) of sulfhydryl inhibitors, e.g., P -chlormercuribenzoate or HgCl 2 , or reduced with dithiothreitol (> monothiols), the response of adenylate cyclase to isoproterenol or glucagon either in whole cells or in subsequently isolated membranes is severely decreased (approx. 60–80%) while the basal activity is relatively less affected, showing a decrease of −25 to −30%. This inhibition is reversible by appropriate treatment of the cells with low concentration 0.1–1 mM) of H 2 O 2 which per se causes a partial increase (140–150%) in the basal adenylate cyclase activity and in the submaximal, but not maximal, hormone-response in isolated membrane when cells are treated with it for 3–5 min. The cellular content of cyclic AMP parallels, in general, with the adenylate cyclase response to hormones under the above treatments. The stimulation of adenylate cyclase by NaF added to cell-free membranes is not affected by pre-treatment of cells with either thiols, mercurials or H 2 O 2 . The evidence suggests that the hormonal stimulation of the adenylate cyclase-cyclic AMP system in these cells is impaired by either reduction or blockage of some labile sulfhydryl groups in a pre-catalytic site, while the available hormone-receptors or the catalytic site(s) remain unaltered. On the other hand, the hormonal elicitation of the adenylate cyclase-cyclic AMP system appears to involve an initial oxidation of these susceptible (external)-SH sites, which may be in the ‘coupling’ component. This type of regulation is distinct from the deactivation of the internal catalytic site by oxidants or electron acceptors, or its protection by thiols (Mukherjee, S.P. and Lynn, W.S. 1976 Fed. Proc. 35, 1702; Mukherjee, S.P. and Lynn, W.S. 1977 Arch. Biochem. Biophys, 184, 69; Mukherjee, S.P. and Lynn, W.S. 1979 Biochim. Biophys. Acta 568, 224).
116 DETECTION OF PRECLINICAL LEFT VENTRICULAR DYSFUNCTION USING METHOXAMINE AFTERLOAD CHALLENGE IN PATIENTS WITH THALASSEMIA MAJOR

116 DETECTION OF PRECLINICAL LEFT VENTRICULAR DYSFUNCTION USING METHOXAMINE AFTERLOAD CHALLENGE IN PATIENTS WITH THALASSEMIA MAJOR
A new look at POTATOES

During the last 30 years there have been many and dramatic changes to the pattern of potato production and distribution in the UK. Varieties and cultural techniques have changed and so, too, have post‐harvest handling, storage, marketing and distribution. Any or all of these might have had an effect on the nutritional value of the potato but whether this was so was not known until a two‐year nutritional evaluation of retail potatoes in the UK was recently completed. This work was financed by the Ministry of Agriculture, Fisheries and Food and carried out by Paul Finglas and Richard Faulks at the Food Research Institute, Norwich.
Changes in diaphragm polyinositol phosphates caused by a large body surface area burn

Abstract Respiratory problems are common among burn patients, and an understanding of the changes that occur in the phosphatidyl inositol signal transducing system (s.t.s.) in diaphragm muscle may identify pharmacological agents that would be useful in the treatment of these patients. This report examines changes that occur in polyinositol phosphates of diaphragm muscle due to the systemic effects of large (> 30 per cent) body surface area (per cent BSA) burns. Burn injury was applied to specific per cent BSA of the dorsal and ventral skin surfaces of mice. At postburn day 21, polyinositol phosphate levels were measured in the diaphragm by the incorporation of myo-[2 −3 h]inositol with separation of the phosphates by anion-exchange chromatography. All data were analysed using analysis of variance and curve fitting. In the diaphragm, levels of [ 3 H]inositol, inositol-1,4,5 trisphosphate (IP 3 ), inositol-1,4 bisphosphate (I1,4P 2 ) and inositol-1 phosphate (I1P) increased with increasing burn size. Furthermore, a variety of independent relationships existed between the various phosphates in each burn group (i.e. control, 20 per cent and 50 per cent BSA burn). These data indicate that the systemic effects of burn trauma result in changes in the polyinositol phosphate part of the phosphatidyl inositol signal transducing system of diaphragm muscle.
Vascular Compliance during Insulin Infusion and Oral Glucose Challenge

Abstract Background Vascular stiffness predicts cardiovascular disease (CVD). Pulse wave velocity (PWV), reflecting vascular stiffness, though determined largely by mean arterial pressure; is also sensitive to insulin and glucose. Capacitance in small (C2) and large vessels (C1), reflecting vascular responsiveness to hemodynamic challenges, may also be influenced by insulin and glucose. The purpose of this study was to test the effects of insulin and glucose on arterial function in healthy individuals. Methods Excluding people with BMI >27.5 kg/m 2 , diabetes, impaired glucose tolerance, hypotension or hypertension, 14 adults were enrolled. Subjects underwent randomly either a 2 h euglycemic clamping, or a 2-h OGTT first, with the other procedure performed up to one month later. Pulse wave velocity (PWV) and vascular compliance were measured by tonometry. Results The sample ( n = 14) included 10 Caucasians, 8 males, mean age = 28 ± 8 years, BMI = 24 ± 2 kg/m 2 , SBP = 113 ± 9 mmHg, DBP = 70 ± 6 mmHg, and glucose = 73 ± 11 mg/dl. There was a significant increase in mean PWV between 30 and 120 min ( p = 0.049), during the euglycemic clamp. PWV change during OGTT was not significant. Conclusion PWV increased during euglycemic clamp conditions without significant changes in C1 or C2. Oral glucose had less effect on PWV and changes in C1 and C2 were minimal. These data support mechanisms that link insulin and arterial stiffness in vascular physiology and suggest that part of the mechanism of CVD in insulin resistance may relate to insulin's effects on arterial stiffness.
Methylation of the O6 position of guanine in DNA is the most likely initiating event in carcinogenesis by methylating agents.

(1984). Methylation of the O6 Position of Guanine in DNA is the Most Likely Initiating Event in Carcinogenesis by Methylating Agents. Cancer Investigation: Vol. 2, No. 3, pp. 223-231.
Production of pyruvate and succinate by action of isocitrate lyase on α-methylisocitrate

Abstract The cleavage of α-methylisocitrate to equimolar pyruvate and succinate is catalyzed by homogeneous isocitrate lyase from Pseudomonas indigofera . Isocitrate lyase which has been inactivated to various extents with β-bromopyruvate, an active-site reagent, catalyzes a constant ratio of rates of cleavage for d s -isocitrate and α-methylisocitrate. This corroborates the function of one enzyme in cleaving both substrates. Reversal of cleavage of α-methylisocitrate is not detected. The equilibrium constant at 30 °, pH 7.7, in the direction of condensation is not greater than 0.3 m −1 compared with 430 m −1 (1) for formation of isocitrate. No evidence is found for Schiff-base formation between isocitrate lyase and pyruvate or glyoxylate during catalysis. K m values for α-methylisocitrate at 30 ° are 0.1 m m at pH 7.7, 0.3 m m at pH 6.8, and 0.6 m m at pH 7.0, for enzymes from P. indigofera , Neurospora crassa , and Saccharomyces cerevisiae , respectively. Maximal velocity ratios for d s -isocitrate/α-methylisocitrate cleavage at 30 ° are 20 and 6.7 at pH 7.7, 50 at pH 6.8, and 5 at pH 7.0 for enzymes from P. indigofera , Chlorella vulgaris , N. crassa , and S. cerevisiae , respectively.
Effect of sodium carboxymethyl celluloses on water-catalyzed self-degradation of 200 °C-heated alkali-activated cement

Abstract This paper investigates the usefulness of sodium carboxymethyl celluloses (CMC) in promoting self-degradation of 200 °C-heated sodium silicate-activated slag/Class C fly ash cementitious material after contact with water. CMC emitted two major volatile compounds, CO2 and acetic acid, creating a porous structure in cement. CMC also reacted with NaOH from sodium silicate to form three solid reaction products, disodium glycolate salt, sodium glucosidic salt, and sodium bicarbonate. Other solid reaction products, such as sodium polysilicate and sodium carbonate, were derived from hydrolysates of sodium silicate. Dissolution of these products upon contact with water generated heat that promoted cement’s self-degradation. Thus, CMC of high molecular weight rendered two important features to the water-catalyzed self-degradation of heated cement: one was the high heat generated in exothermic reactions in cement; the other was the introduction of extensive porosity into cement.
A BAYESIAN HIERARCHICAL FRAMEWORK FOR SPATIAL MODELING OF fMRI DATA

Abstract Applications of functional magnetic resonance imaging (fMRI) have provided novel insights into the neuropathophysiology of major psychiatric, neurological, and substance abuse disorders and their treatments. Modern activation studies often compare localized task-induced changes in brain activity between experimental groups. Complementary approaches consider the ensemble of voxels constituting an anatomically defined region of interest (ROI) or summary statistics, such as means or quantiles, of the ROI. In this work, we present a Bayesian extension of voxel-level analyses that offers several notable benefits. Among these, it combines whole-brain voxel-by-voxel modeling and ROI analyses within a unified framework. Secondly, an unstructured variance/covariance matrix for regional mean parameters allows for the study of inter-regional (long-range) correlations, and the model employs an exchangeable correlation structure to capture intra-regional (short-range) correlations. Estimation is performed using Markov Chain Monte Carlo (MCMC) techniques implemented via Gibbs sampling. We apply our Bayesian hierarchical model to two novel fMRI data sets: one considering inhibitory control in cocaine-dependent men and the second considering verbal memory in subjects at high risk for Alzheimer’s disease.
SLUG: A Connectionist Architecture for Inferring the Structure of Finite-State Environments

Consider a robot wandering around an unfamiliar environment, performing actions and sensing the resulting environmental states. The robot's task is to construct an internal model of its environment, a model that will allow it to predict the consequences of its actions and to determine what sequences of actions to take to reach particular goal states. Rivest and Schapire (1987a, 1987bs Schapire, 1988) have studied this problem and have designed a symbolic algorithm to strategically explore and infer the structure of “finite state” environments. The heart of this algorithm is a clever representation of the environment called an update graph. We have developed a connectionist implementation of the update graph using a highly-specialized network architecture. With back propagation learning and a trivial exploration strategy—choosing random actions—the network can outperform the Rivest and Schapire algorithm on simple problems. Perhaps the most interesting consequence of the connectionist approach is that, by relaxing the constraints imposed by a symbolic description, it suggests a more general representation of the update graph, thus allowing for greater flexibility in expressing potential solutions.
Better than better-than-average (or not): Elevated and depressed self-evaluations following unfavorable social comparisons

Two experiments were designed to investigate perceivers' self-evaluations when they received objectively positive above-average performance feedback but were told about another coactor who performed either moderately or much better than the participant. Results indicated that participants responded negatively to this comparison information even though they received better-than-average performance feedback. Participants were given the opportunity to evaluate themselves relative to another coactor who was described as performing at an average level. When the negative implications of the unfavorable social comparisons were relatively mild, both low and high self-esteem participants raised their self-evaluations vis-a-vis the inferior coactor who performed at an average level on the task. However, when the upward comparisons were especially unfavorable (i.e., when there was a large discrepancy between the performance level of the participant and the coactor—the comparison target), only high self-esteem partic...
Estimation Methods for an Autoregressive Familial Correlation Structure

In this article, we apply an autoregressive correlation structure to the analysis of balanced familial clustered data in the one-parent case with homogeneous intra-class variance. We use the quasi-least squares procedure to derive estimators of the correlation parameters and compare them with maximum likelihood and moment estimators. Asymptotically, the quasi-least squares estimators are nearly as efficient as the maximum likelihood estimators. The small-sample case is analyzed through simulation, and the quasi-least squares estimators are found to be more robust than the maximum likelihood estimators. To show the application of the estimation procedures, data provided in Katapa (1993) are re-analyzed. For non stationary unbalanced familial data, we outline general correlation models which are natural extensions of the structure studied in this article.
Estimating Selection on Synonymous Codon Usage from Noisy Experimental Data

A key goal in molecular evolution is to extract mechanistic insights from signatures of selection. A case study is codon usage, where despite many recent advances and hypotheses, two longstanding problems remain: the relative contribution of selection and mutation in determining codon frequencies and the relative contribution of translational speed and accuracy to selection. The relevant targets of selection—the rate of translation and of mistranslation of a codon per unit time in the cell—can only be related to mechanistic properties of the translational apparatus if the number of transcripts per cell is known, requiring use of gene expression measurements. Perhaps surprisingly, different gene-expression data sets yield markedly different estimates of selection. We show that this is largely due to measurement noise, notably due to differences between studies rather than instrument error or biological variability. We develop an analytical framework that explicitly models noise in expression in the context of the population-genetic model. Estimates of mutation and selection strength in budding yeast produced by this method are robust to the expression data set used and are substantially higher than estimates using a noise-blind approach. We introduce per-gene selection estimates that correlate well with previous scoring systems, such as the codon adaptation index, while now carrying an evolutionary interpretation. On average, selection for codon usage in budding yeast is weak, yet our estimates show that genes range from virtually unselected to average per-codon selection coefficients above the inverse population size. Our analytical framework may be generally useful for distinguishing biological signals from measurement noise in other applications that depend upon measurements of gene expression.
Essential Role of Flavohemoglobin in Long-Term Anaerobic Survival of Bacillus subtilis

A Bacillus subtilis culture incubated anaerobically in nitrate-containing medium lost viability during the first 3 days but recovered thereafter. A flavohemoglobin mutant showed very poor survival under these conditions unless the cells were prevented from carrying out nitrate respiration.
Maximum entropy relaxation for multiscale graphical model selection

We consider the problem of learning multiscale graphical models. Given a collection of variables along with covariance specifications for these variables, we introduce hidden variables and learn a sparse graphical model approximation on the entire set of variables (original and hidden). Our method for learning such models is based on maximizing entropy over an exponential family of graphical models, subject to divergence constraints on small subsets of variables. We demonstrate the advantages of our approach compared to methods that do not use hidden variables (which do not capture long-range behavior) and methods that use tree-structure approximations (which result in blocky artifacts).