cssi/SciSciGPT-SciSciNet huggingface dataset:
Mechanism of canavanine death in Escherichia coli. I. Effect of canvainine on macromolecular synthesis.

Abstract Canavanine-dead Escherichia coli are unable to support the growth of T-even bacteriophage. Loss of the ability to make virus is directly related to the kinetics of canavanine death and is due to the synthesis of host protein containing canavanine. T4-infected canavanine-dead cells did not form phage-induced messenger RNA and consequently no phage-induced protein and DNA synthesis were observed. Amino acid incorporation into protein by cell-free extracts indicated a defect in the protein synthesizing system of canavanine-dead cells. It is shown that the washed ribosomes from dead cells are only slightly active while the soluble fraction is normal. Activity is restored when synthetic mRNA is supplied to ribosomes from cells rendered non-viable by canavanine. Thus, the protein synthesizing machinery in canavanine-dead E. coli appears intact and the low level of mRNA in cell extracts indicates that very little transcription takes place in the dead cells. Crude extracts from dead cells show high levels of RNA polymerase activity. However, plasmolyzed canavanine-dead cells show lowered levels of RNA synthesis in the presence of exogenous ribonucleoside triphosphates. DNA synthesis is not initiated in dead cells by supplying excess arginine followed by plasmolysis and the addition of deoxynucleoside triphosphates. Canavanine-dead cells retain the ability to oxidize glucose and generate ATP. These results are consistent with the hypothesis that, during canavanine death, proteins containing this amino acid analog are synthesized, which eventually block transcription of all DNA in the intact cell.
Halstead‐Reitan Neuropsychological Test Battery

The Halstead-Reitan Neuropsychological Test Battery consists of a series of individual neuropsychological measures that, in combination, permit a skilled examiner to make detailed inferences about the integrity of the cerebral hemispheres. Because the brain is the organ of adaptive behavior, brain dysfunction is typically observable in some behavioral aberrations. The tests included in the Halstead-Reitan Battery are designed to sample behavior across every possible sphere and assess all major cognitive, sensory, expressive, and motor functions. Keywords: halstead-reitan neuropsychological test battery; brain damage; neuropsychological impairment; brain-behavior relationships
Use of Recurrent Neural Networks for Bioprocess Identification in On-line Optimization by Micro-Genetic Algorithms

The use of recurrent neural networks in bioprocess identification and optimization is investigated. A recurrent neural network is trained on a set of fermentation data, and there-after used as a nonlinear process model to estimate nonmeasurable process states at different conditions. With the bioprocess state variable information available, an optimization technique can be used to generate optimum controls settings to improve the process performance. This paper explores the use of Micro-Genetic Algorithms as a technique for bioreactor optimization. Simulation results will be discussed based in the fermentative ethanol production by the anaerobic bacteria Zymomonas mobilis.
Unusual bleeds, unusual clots

Nine unusual bleeding and clotting disorders (or mimickers of such) are described in the format of case presentations, with focus on clinical history, images and diagnostic tests, followed by a discussion of the disease itself and a summarizing clinical teaching point. The disease entities discussed are acquired factor VIII inhibitor, acquired von Willebrand factor inhibitor, haemophilic pseudotumour, Gardner-Diamond syndrome, coumarin-induced skin necrosis, purple toe syndrome, brachiocephalic vein thrombosis with breast enlargement, and leg swelling due to nephrogenic fibrosing dermopathy and lymphoedema. The publication is meant to demonstrate the fascination of clinical coagulation.
Do Competitive Activities Influence Middle School Physical Education Students' Attitudes and Perceptions?

What Was the Question? Bernstein, Phillips, and Silverman (2011) examined the attitudes and perceptions of middle school students toward competitive activities in physical education. Specifically, ...
Quantitative 15N NMR spectroscopy

Line intensities in 15N NMR spectra are strongly influenced by spin-lattice and spin–spin relaxation times, relaxation mechanisms and experimental conditions. Special care has to be taken in using 15N spectra for quantitative purposes. Quantitative aspects are discussed for the 15N NMR of molecules with different nitrogen functional groups and also mixtures of nitrogen-containing compounds. It is shown that, in general, quantitative data are obtainable from integration of 15N lines in proton decoupled 15N NMR spectra using NOE suppression. Addition of paramagnetic relaxation reagents (PARR) under controlled conditions is frequently needed to accomplish the experiment within reasonable time limits.
Gastroparesis as a cause of nausea and vomiting after high-dose chemotherapy and haemopoietic stem-cell transplantation.

Nausea and vomiting in patients undergoing high-dose chemotherapy and stem-cell transplantation (SCT) is a formidable clinical challenge despite the use of potent antiemetics. Gastroparesis is recognised as a cause of unexplained vomiting, but has not been investigated in relation to high-dose chemotherapy and SCT. As there are effective prokinetic agents, such as erythromycin, finding gastroparesis in this population could have therapeutic implications. We reviewed our experience of gastroparesis among patients with nausea and vomiting after high-dose chemotherapy and SCT, over 3 years. 13 of 24 gastric emptying studies (GES) done in 22 patients showed delayed emptying. One patient with delayed emptying, who was found to have adrenal insufficiency, was excluded (table). No cases of gastricoutlet obstruction or viral infection were identified in 19 patients who underwent upper endoscopy. Of the 15 treated with intravenous erythromycin, the majority responded. No statistically significant association between either GES result or response to erythromycin and any clinical feature was found. Our review suggests that gastroparesis may be responsible for many instances of delayed-onset nausea and vomiting after high-dose chemotherapy and SCT, whether allogeneic or autologous. Interpretation of our study is limited by its retrospective design, small study population, and lack of controls. Intravenous erythromycin seemed to help these patients. As erythromycin was used only after failure of all other available antiemetic agents, we believe that the responses observed were related to its promotility effect. Our inability to show an association between an abnormal gastric emptying study and response to treatment with erythromycin was probably attributable to an insufficiently large sample size. Furthermore, correlation between symptom response and gastric emptying status is known to be highly variable. Gastroparesis may also be responsible for similar prolonged symptoms after conventional chemotherapy regimens. A prospective study is in progress to confirm this association and better characterise response to erythromycin.
Comparison of secretion of catecholamines from the rat adrenal medulla during continuous exposure to nicotine, muscarine or excess K.

Abstract The effects of continuous exposure of chromaffin cells to nicotine, muscarine and excess potassium on the secretion of catecholamines and uptake of radiolabeled calcium were investigated in the isolated perfused adrenal gland of the rat. Perfusion with 20μM nicotine-Krebs solution increased catecholamine secretion from a basal value of 5 ng to 273 ng in the first 5 min. The secretion declined to about 20 ng after 30 min of continuous exposure to nicotine (slow desensitization). 200 μM muscarine increased the secretion to about 150 ng within the first 5–10 min, and remained at the level of 110 ng even after continuous perfusion with muscarine for up to 40 min (no desensitization). About 700 ng of catecholamines were secreted within the first 5 min of exposure to 55 mM K, the secretion declined to about 350 ng in the next 5 min, and remained almost at this level for 120 min during continuous perfusion with excess K (partial desensitization). When the secretion of catecholamines was depressed by continuous exposure to nicotine for 30 min, introduction of 55 mM K or 200 μM muscarine (along with nicotine) still led to a large increase in the secretion of catecholamines. Omission of calcium ions from the perfusion medium containing either nicotine or 55 mM K caused a rapid decline in the secretion of catecholamines, suggesting influx of external calcium, but muscarine-induced secretion was only modestly reduced by calcium removal, suggesting mobilization of internal calcium. Addition of EGTA to calcium-free medium completely abolished the secretion evoked by all agents. Nicotine-evoked secretion was associated with an increase in the uptake of 45 Ca as expressed in terms of pg/mg wet weight (92 pg/mg at rest, and 234 pg/mg after stimulation with nicotine). However, after continuous exposure to nicotine the uptake of 45 Ca did not increase significantly when tested at a 30-min period. K-evoked secretion was associated with an increase in the uptake of 45 Ca, and this increase was detected even after 60 min of continuous exposure to high-K solution (267 pg/mg). After continuous treatment with nicotine for 30 min, if the adrenal gland was perfused with 55 mM K-Krebs solution the uptake of 45 Ca was still increased (253 pg/mg). It appears that the voltage-sensitive calcium channels opened by excess K do not undergo rapid inactivation and remain open to allow influx of extracelllar calcium and secretion of catecholamine for hours. Our study shows that secretion is well maintained during prolonged stimulation of the rat adrenal medulla with excess K or muscarine. The results are of potential importance to investigate the processes of synthesis, storage and secretion when the adrenal medulla is stimulated over extended periods of time.
A solo luxI-type gene directs acylhomoserine lactone synthesis and contributes to motility control in the marine sponge symbiont Ruegeria sp. KLH11.

Marine sponges harbour abundant and diverse bacterial communities, providing an ideal environment for bacterial cell-density-dependent cell–cell signalling, termed quorum sensing. The marine sponge symbiont Ruegeria sp. KLH11 produces mainly long chain acylhomoserine lactones (AHLs) and has been developed as a quorum sensing model for roseobacterial sponge symbionts. Two pairs of luxR/I homologues were identified by genetic screening and were designated ssaRI and ssbRI (sponge-associated symbiont locus A or B, luxR/luxI homologue). In this study, we identified a third luxI-type gene, named sscI. The sscI gene does not have a cognate luxR homologue present at an adjacent locus and thus sscI is an AHL synthase solo. The sscI gene is required for production of long-chain hydroxylated AHLs, contributes to AHL pools and modestly influences flagellar motility in KLH11. A triple mutant for all luxI-type genes cannot produce AHLs, but still synthesizes para-coumaroyl-homoserine lactone.
Thermophysical properties of uranium dioxide

Abstract The thermophysical properties of uranium dioxide from room temperature to 6000 K are reviewed. Properties discussed include: enthalpy, heat capacity, vapor pressure, density, thermal expansion, compressibility, thermal conductivity, viscosity, and emissivity. Estimates of the reliability of the recommended values are given; needs for further experiments are pointed out.
Properties of lithium hydride—III. Paramagnetic resonance of color centers

Concentrations of F-centers in excess of 1017cm3 have been produced in single crystals of LiH by neutron irradiation at 78°K. The ESR absorption of the F-centers has been observed at g = 2.004 ± 0.001. The saturation parameter of the ESR absorption (T1T2)12 is dose to that for F-centers in KC1. From r.m.s. line width measurements on LiH crystals of various isotopic compositions (Li7H, Li7D, Li6H and Li6D), spin densities of the F-center electron at the Li+ and H− sites have been estimated.
Desert Island Books

Eugene Spafford discusses the books that have been most influential in shaping his attitudes about security and privacy.
Soy isoflavones have an antiestrogenic effect and alter mammary promoter hypermethylation in healthy premenopausal women.

We determined if soy isoflavones have dose-related estrogenic and methylation effects. Thirty-four healthy premenopausal women were randomized to 40 mg or 140 mg isoflavones daily through one menstrual cycle. Breast specific and systemic estrogenic effects were assessed measuring the estrogenic marker complement (C)3 and changes in cytology, whereas methylation assessment of 5 cancer related genes (p16, RASSF1A, RAR β 2, ER, and CCND2) was performed on intraductal specimens. Serum genistein significantly increased after consuming both isoflavone doses. Cytology did not significantly change at either isoflavone dose. Serum C3 levels posttreatment were inversely related to change in serum genistein ( r =–0.76, P = 0.0045) in women consuming low but not high dose isoflavones. The RAR β 2 hypermethylation increase posttreatment correlated with the posttreatment genistein level considering the entire group ( r = 0.67, P = 0.0017) and those receiving high-dose isoflavones ( r = 0.68, P = 0.021). At the low but ...
Borderline resectable pancreatic cancer: what have we learned and where do we go from here?

The success of any future trial relies on the adoption of a single objective definition of borderline resectable PDAC. At present, two definitions have been proposed. We developed the MDACC definition, used by Stokes et al., in an attempt to identify patients with primary tumor anatomy, cancer biology, or patient physiology which places them at the limits of compatibility with favorable results after neoadjuvant therapy and surgical resection.3 This definition was introduced within the context of a strong institutional preference for the administration of neoadjuvant therapy to all patients with localized PDAC and an opinion that tumor involvement of the superior mesenteric vein and/or portal vein (SMV-PV) (in the absence of arterial involvement) is consistent with potentially resectable anatomy. The criteria for borderline resectable disease were therefore meant neither to justify the role of neoadjuvant therapy among a subset of patients with localized cancers, nor to estimate their potential need for venous resection and reconstruction.8 The MDACC anatomic definition differs from that recently proposed by the American Hepato-Pancreato-Biliary Association (AHPBA), Society of Surgical Oncology (SSO), and Society for Surgery of the Alimentary Tract (SSAT), particularly with regards to the classification of tumors with minimal vein involvement. Indeed, the AHPBA/SSO/SSAT definition classifies primary cancers with any degree of vein involvement—from slight abutment to outright venous occlusion—as borderline resectable.9 Moreover, in contrast to our group, the AHPBA/SSO/SSAT uses the borderline resectable definition as the basis for recommendations regarding treatment sequencing: surgery is recommended as the standard initial approach for resectable patients, and neoadjuvant therapy (and a heightened awareness of the potential need for SMV-PV resection) is recommended for borderline resectable patients.10 We believe that the definition of borderline resectable PDAC proposed by the AHPBA/SSO/SSAT may be somewhat broad. Nonetheless, given national practice patterns that, at present, continue to strongly favor the use of initial surgery among patients with PDAC that does not involve the mesenteric vasculature, and given the survival benefit associated with the use of neoadjuvant therapy for tumors that at least compress the SMV unilaterally, a definition close to that proposed by the AHPBA/SSO/SSAT should be able to guide management and serve as an inclusion or exclusion criterion for future national trials of treatment for patients with borderline resectable PDAC.4,11 Whatever definition is ultimately adopted, it must be objective, clear, and—most importantly—consistently applied.
Review of the treatment of trigeminal neuralgia with gamma knife radiosurgery.

Background: Trigeminal neuralgia is a debilitating condition caused by compression of the trigeminal nerve, ganglions, or divisions. Gamma knife radiosurgery has been increasingly used in the treatment of trigeminal neuralgia as a non-invasive alternative to microvascular decompression and rhizotomies. Methods: We reviewed the medical literature regarding outcomes, time course, and prognostic factors for successful pain control in gamma knife radiosurgery. The dosimetry, target, complications of treatment, as well as perceived quality of life in treatment were also reviewed. Results and Conclusion: The growing body of literature suggests that the low rates of complications of gamma knife radiosurgery, coupled with the high success rates and patient satisfaction, allow it to be increasingly used as primary intervention for trigeminal neuralgia for appropriate patients.
Trans-endplate nucleotomy increases deformation and creep response in axial loading.

Knowledge of the functional role of the nucleus pulposus is critical for the development and evaluation of disc treatment strategies to restore mechanical function. While previous motion segment studies have shown that nucleotomy alters disc mechanics, disruption of the annulus fibrosus may have influenced these experiments. The objective of this study was to determine the mechanical role of the nucleus pulposus in support of axial loads via a trans-endplate nucleotomy procedure. Sheep motion segments were randomly assigned to three groups: control, limited nucleotomy, and radical nucleotomy. Mechanical testing consisted of 20 cycles of compression–tension, a 1-h creep, and a slow constant-rate compressive ramp test. Nucleotomy led to increased axial deformations, in particular an elongated neutral zone, a greater range of motion, and altered creep behavior. In general, the elastic properties exhibited a graded response with respect to the amount of nucleus material removed. This graded effect can be attributed to swelling of the nucleus pulposus in the limited nucleotomy group, whereas little swelling was observed in the radical group. The findings of the present study indicate that functional evaluation of nucleus pulposus replacements and disc implants should include range of motion measures (including neutral zone) and viscoelastic creep experiments in addition to considering compressive stiffness.
Validation of the integrated upward–horizontal–downward wicking test for providing intensive properties of textile fabrics

Traditional wicking tests provide information that is specific to the test fluid, apparatus, and conditions. As a result, this information cannot be used to make predictions about wicking rates beyond the respective test parameters. In contrast, a new upward–horizontal–downward (UHD) wicking test has been presented that provides intensive properties of fabrics in the form of permeability (k) and effective capillary radius (R c) as functions of saturation (S). The UHD test was developed using water as the test fluid. If the k–S–R c relationships are truly intrinsic to a given fabric, then they should not depend on the test fluid. Here, we conducted the UHD test on a knit fabric using three different test fluids characterized by different surface tensions, densities, and viscosities: dodecane, tetradecane, and hexadecane. All fluids fall on the same k vs. S and k vs. R c curves, proving that these curves are intrinsic characteristics of the fabric. We then used the k–S–R c properties to successfully predict...
Chromosomal location of antibiotic resistance markers in Bacillus subtilis.

Abstract Resistance loci for a number of antibiotics known to inhibit protein synthesis have been mapped on the Bacillus subtilis W168 genome by transformation, PBS1 transduction and density transfer analysis. Most of the markers are clustered near the replication origin and presumably adjacent to genes for RNA species. The map order found is ade16, nov, pac, cysA14, rfm, bry, str, neo, kan, ery-ole, spc, lin. Recombination among neomycin-resistant mutants has also been demonstrated. Novobiocin inhibits both DNA and RNA synthesis in vivo but neither DNA polymerase nor RNA polymerase in vitro. Its mode of action is unknown. The resistance of mutants to rifampicin is correlated with in vitro insensitivity of RNA polymerase to the drug. A number of resistance loci map outside the early region, including 11 spectinomycin-resistant mutants located at 0.72 on the synchro-transfer map and two neomycin-resistant mutants. The function of these loci is not known.
Mercury residues in duck breast tissue after moist and dry heat cooking.

Fifty McGraw Mallard ducks were given methyl-mercury chloride (MeHg) at dosage levels of 0.0, 2.0, 6.0, 10.0 and 19.0 mg/kg body weight. Breasts were either roasted or braised and mercury concentration in cooked tissue and in drip was compared with that in the raw breast. The amount of mercury recovered after cooking averaged 87.6% after braising and 96.6% after roasting. Mercury losses were not significantly reduced by either cooking method.
United colors and untied meanings: Benetton and the commodification of social issues

The Benetton United Colors campaign illustrates how modern advertising has been radicalized into an explicitly political forum. Although lifestyle companies often attempt to associate their products with progressive social movements, Benetton was the first company to eliminate pictures of its products from its advertisements. In 1989, ads depicting Benetton's sportswear were replaced with powerful and problematic visual images of AIDS, environmental disasters, terrorism, and racism. Social issues became the embodiment of Benetton's product and, through the transformation into commodities, lost their significance as problematic human conditions. The campaign illustrates how the decontextualization of placing issues within the framework of product promotion, creates a tone of discordant meaning not adequately explained by mass culture critiques of consumerism. This case study recommends that advertising should be studied as a complex and contested social discourse within 1990s consumer culture.
A Voortrekker Memorial in Revolutionary Maputo

On a side street of downtown Maputo, two blocks from a statue of Samora Machel, is a half-acre memorial to the ill-fated Trichardt party, which in the 1830s arrived at the Bay of Lourenco Marques after a years-long trek, only to be decimated by malaria. The memorial was inaugurated in 1968, one of countless memorials to Voortrekkers to be constructed since the 1930s, in parallel with the rise of Afrikaner nationalism, and the only one to be built outside the borders of South Africa. That the memorial kept its gates open after Mozambique's independence, and continued to be maintained at a time when apartheid South Africa sponsored Renamo and on several occasions attacked Mozambique directly – a time when Maputo was a city virtually under siege and falling into physical ruin – makes the memorial something more than a mere curiosity. This article tells the history of the memorial from its beginnings until today, with a focus on Mozambique's revolutionary era, and is based primarily on the archives of the Pre...
Public Understanding to Political Voice: Action Research and Generative Curricular Practices in Issues and Reform

The author and preservice teachers in a postbaccalaureate Issues and Reform in Secondary Education course engaged Ernest Stringer's (2004) model of action research to develop generative curricula. They adhered to Walter C. Parker's (1991, 2006) vision of public formation and essential social studies teaching and used student-centered teaching based on students' knowledge needs, which were determined through observation, formative assessments, and two questionnaires. As suggested in Parker's work supporting participatory democracy, the public, including public school teachers, must engage in public discussion and become active in the government's activities of solving public problems. In this article, the author focuses on procedures teachers can follow to implement action research to motivate public understanding and participation in the social studies classroom. Through generative curricula, the students exercised participatory citizenship for democratic ideals promoting cultural diversity and fairer eco...
Effect of Some Manufacturing Variables on the Leakage Defect of Blue Cheese

Abstract Effect of certain manufacturing variables on the leakage (water-exuding defect of 60-day-old Blue cheese was examined by a split-plot experimental design. The variables on a pilot-plant scale were starter culture, the treatment of cream or milk for whitening, amounts and types of nonfat dry milk fortification of vat milk, amount of salt added to the curd at hooping, temperature during overnight drainage in hoops, and type of coating used over the cheese during curing. Chemical analyses of cheeses for pH, salt, milk fat, and proteolysis index were made after 24 hr and (or) 60 days after manufacture. Flavor evaluations were made after 60 days. Statistical analyses of the data showed that the starter culture, rate of salt addition, temperature of overnight drainage, and the whitening treatment for the cream were highly significant in influencing the leakage tendency of 60-day-old Blue cheese. No statistical correlation, however, was obtained between any of the manufacturing variables and the flavor scores of cheeses.
Adrenal morphometry in unilateral and sham adrenalectomized Syracuse high and low avoidance rats.

Abstract Syracuse high (SHA) and low (SLA) Long-Evans rats, bred for differences in avoidance performance, exhibit dramatic differences in adrenal gland weight. Here we examined adrenal weight and composition (i.e., the size of the medulla, zonae fasciculata/reticularis and glomerulosa) following unilateral adrenalectomy and sham surgery in these strains. Adrenals of SLA animals, regardless of treatment, were heavier and contained larger medullas and cortices than did adrenals of SHA animals. When individual regions were expressed as a percent of total adrenal area, SHA glands (age 31–45 days), although smaller in weight, contained a larger percentage of glomerulosa than did adrenals of SLA animals. Unilateral adrenalectomy produced significant compensatory growth in SHA and SLA animals as indexed by increases in adrenal weight as soon as 7 days after surgery. The adrenal enlargement was the net result of an increase in absolute size of the fasciculata/reticularis (significant 14 days following surgery) and a decrease in the absolute size of glomerulosa (significant 7 days following surgery). These results suggest that SHA and SLA adrenal differences may be the result of genetically determined differential pituitary-adrenal activity.
Abdominal aortic aneurysm wiring: an alternative method.

Abstract Intraluminal wire reinforcement of symptomatic aortic aneurysms in extremely poor risk patients was performed. Hospital mortality was 12.5 per cent with actuarial survival of 74 and 33 per cent at one and five years, respectively. There was improved survival and decreased incidence of rupture compared with untreated patients. Thus, aneurysm wiring is a feasible alternative in treating poor risk patients with extensive aortic disease.
African dry air outbreaks

[1] Dry air outbreaks from Africa into the tropical Atlantic region are documented using daily layered precipitable water (LPW) data of satellite remote sensing for 1993–1997. A dry air outbreak is defined as an abrupt decrease in middle-troposphere (700–500 hPa) LPW that is greater than 1 mm d−1 and remains below normal for at least two consecutive days in a reference box off the west coast of Africa. Pathways of individual dry air outbreaks thus identified are tracked both forward and backward in time. Dry air outbreaks intruding into the tropical Atlantic may originate from different source regions: the northern Atlantic Ocean, northern Africa, Sahel, and equatorial Africa. Some of these outbreaks can keep their identities up to 2 weeks, propagate across the Atlantic Ocean, and reach South America and the Caribbean Sea. Boreal summer is the overall peak season, with the majority of the outbreaks occurring north of the Intertropical Convergence Zone (ITCZ). In spring more outbreaks occur south of the ITCZ. Precipitation in the ITCZ tends to decrease during periods of the outbreaks in both spring and summer. Observed large-scale patterns of African dry air outbreaks are compared to known characteristics of African dust outbreaks. The results from this study suggest that African dry air outbreaks should and can be treated as prominent phenomena independent of African dust outbreaks. This study calls for systematic investigations on the similarities and differences between African dust and dry air outbreaks for a better understanding of their effects on weather and climate in the tropical Atlantic region.
Cytosolic pH regulation in osteoblasts. Regulation of anion exchange by intracellular pH and Ca2+ ions

Measurements of cytosolic pH (pHi) 36Cl fluxes and free cytosolic Ca2+ concentration ([Ca2+]i) were performed in the clonal osteosarcoma cell line UMR-106 to characterize the kinetic properties of Cl-/HCO3- (OH-) exchange and its regulation by pHi and [Ca2+]i. Suspending cells in Cl(-)-free medium resulted in rapid cytosolic alkalinization from pHi 7.05 to approximately 7.42. Subsequently, the cytosol acidified to pHi 7.31. Extracellular HCO3- increased the rate and extent of cytosolic alkalinization and prevented the secondary acidification. Suspending alkalinized and Cl(-)-depleted cells in Cl(-)-containing solutions resulted in cytosolic acidification. All these pHi changes were inhibited by 4',4',-diisothiocyano-2,2'-stilbene disulfonic acid (DIDS) and H2DIDS, and were not affected by manipulation of the membrane potential. The pattern of extracellular Cl- dependency of the exchange process suggests that Cl- ions interact with a single saturable external site and HCO3- (OH-) complete with Cl- for binding to this site. The dependencies of both net anion exchange and Cl- self-exchange fluxes on pHi did not follow simple saturation kinetics. These findings suggest that the anion exchanger is regulated by intracellular HCO3- (OH-). A rise in [Ca2+]i, whether induced by stimulation of protein kinase C-activated Ca2+ channels, Ca2+ ionophore, or depolarization of the plasma membrane, resulted in cytosolic acidification with subsequent recovery from acidification. The Ca2+-activated acidification required the presence of Cl- in the medium, could be blocked by DIDS, and H2DIDS and was independent of the membrane potential. The subsequent recovery from acidification was absolutely dependent on the initial acidification, required the presence of Na+ in the medium, and was blocked by amiloride. Activation of protein kinase C without a change in [Ca2+]i did not alter pHi. Likewise, in H2DIDS-treated cells and in the absence of Cl-, an increase in [Ca2+]i did not activate the Na+/H+ exchanger in UMR-106 cells. These findings indicate that an increase in [Ca2+]i was sufficient to activate the Cl-/HCO3- exchanger, which results in the acidification of the cytosol. The accumulated H+ in the cytosol activated the Na+/H+ exchanger. Kinetic analysis of the anion exchange showed that at saturating intracellular OH-, a [Ca2+]i increase did not modify the properties of the extracellular site. A rise in [Ca2+]i increased the apparent affinity for intracellular OH- (or HCO3-) of both net anion and Cl- self exchange. These results indicate that [Ca2+]i modifies the interaction of intracellular OH- (or HCO3-) with the proposed regulatory site of the anion exchanger in UMR-106 cells.
Spur and Groove Patterns on the Reefs of the Northern Gulfs of the Red Sea

ABSTRACT Spurs and grooves on the reefs in the northern gulfs of the Red Sea are generally oriented with their long axes normal to the refracted waves. Therefore, they do not lie normal to the reef front but rather intersect it at an angle. There is no correlation between trend of streams on land and the orientation of the spurs and grooves; karstic activity on exposed reef flat surfaces most probably did not play a role in their formation either. Of the eight studied areas, two show clear abrasion patterns; in all others, the seaward growth of corals, as well as abrasion, controls the development of the spur and groove patterns.
Integrated concentration of plasma cortisol in normal subjects.

The integrated concentration (I.C.) of plasma cortisol was determined every 20 min during a 24-hr period, using a blood collection system composed of a non-thrombogenic catheter and a small, portable withdrawal pump. Thirteen experiments were undertaken in 11 adult subjects under daily routine life while a trained observer recorded physical activity as well as psychological reactions. The 24-hr studies were divided in six periods: (I) first 4 hr of sleep; (II) remainder of sleep; (III) from arousal to noon; (IV) from noon to 4 PM; (V) from 4 to 8 PM; (VI) from 8 PM to beginning of sleep. The following was demonstrated: a) The 24-hr profile of plasma cortisol is characterized by consistently high values during periods II and III. The mean I.C. of periods I and VI were similar and significantly lower than those of the other four periods, b) The introduction of the indwelling catheter had no significant influence on the I.C. of cortisol, nor did the food intake, c) It appeared that some episodes of increased...
Transcriptional and epigenetic regulation of Hebbian and non-Hebbian plasticity

The epigenome is uniquely positioned as a point of convergence, integrating multiple intracellular signaling cascades into a cohesive gene expression profile necessary for long-term behavioral change. The last decade of neuroepigenetic research has primarily focused on learning-induced changes in DNA methylation and chromatin modifications. Numerous studies have independently demonstrated the importance of epigenetic modifications in memory formation and retention as well as Hebbian plasticity. However, how these mechanisms operate in the context of other forms of plasticity is largely unknown. In this review, we examine evidence for epigenetic regulation of Hebbian plasticity. We then discuss how non-Hebbian forms of plasticity, such as intrinsic plasticity and synaptic scaling, may also be involved in producing the cellular adaptations necessary for learning-related behavioral change. Furthermore, we consider the likely roles for transcriptional and epigenetic mechanisms in the regulation of these plasticities. In doing so, we aim to expand upon the idea that epigenetic mechanisms are critical regulators of both Hebbian and non-Hebbian forms of plasticity that ultimately drive learning and memory.
Racialization and the State: The Housing Act of 1934 and the Creation of the Federal Housing Administration:

Research examining the impact of corporate interests, state structures, and class contradictions on the state policy formation process has been dominated by three major theoretical perspectives: business dominance theory, state-centered theory, and Marxian structuralism. I argue that these existing perspectives pay insufficient attention to race and racial discrimination as a central component in the formulation and implementation of state policy. This article uses the concept of racialization to reframe existing theories of the state to explain the origin of the Federal Housing Administration (FHA) through the Housing Act of 1934. As an integral component of New Deal legislation, the FHA was created for the purpose of salvaging the home building and finance industries that had collapsed during the Great Depression. I draw on government housing reports and analyses, real estate industry documents, and congressional testimony to examine the racial dynamic of the FHA's housing policies and subsidies. The an...
System theoretic implications of numerical methods applied to the solution of ordinary differential equations

This paper presents a system-theoretic analysis of numerical methods used in approximating solutions of ordinary differential equations. By representing ordinary differential equations with system block diagrams (i.e., interconnections of static elements and integrators), a numerical method can be viewed as a process in which the integrators of a continuous system are replaced by discrete approximations to the integrators (i.e., by discrete subsystems made up of interconnections of static elements and delays). The main result of the paper establishes that if the system block diagram corresponding to the original differential equation has no static loops and if the discrete subsystems used to replace the integrators have no static loops and no static through paths, then the resulting discrete system can be characterized by explicit difference equations. A system-theoretic study is conducted of several of the more commonly used numerical methods (the Euler, trapezoidal, Runge-Kutta, and predictor-corrector methods) and the limitations of using these numerical methods in the real-time analysis of input-output systems are examined.
Many-body effects in gain and refractive-index spectra of bulk and quantum-well semiconductor lasers

Gain and refractive-index spectra for bulk and quantum-well semiconductor lasers are computed using quantum-mechanical many-body theory. The results clearly show the influence of band-gap renormalization, broadening, and Coulomb enhancement on the gain, the absorption, and the refractive-index spectra.
The origins of international physicians for the prevention of nuclear war: The Dr James E. Muller Diaries*

Based on the diaries of Dr James E. Muller, this article reports his role in the events leading to the founding of International Physicians for the Prevention of Nuclear War, and in the early work of the organization. His early interest in US‐Soviet relationships and his visits to the former Soviet Union are described. His key role in the successful cardiopulmonary resuscitation of the Russian correspondent Lev Novikov, at the press conference in Oslo marking the award of the 1985 Nobel Peace Prize to IPPNW, is stressed.
The comparative binding characteristics of nicotinic ligands and their pharmacology.

Abstract Five drugs [(−)- and (+)-nicotine, (−)-lobeline, (−)-anabasine and (−)-cytisine] were infused IV into the urethane-pentobarbital anesthetized rat. Changes in heart rate, blood pressure, respiratory rate, minute and tidal volume, which appeared to be largely centrally mediated, were studied. Each of these compounds produced different pharmacologic profiles. The nature of these dissimilarities is not readily explained on the basis of pharmacokinetic considerations suggesting that the drugs have different mechanisms of action. Binding data obtained with these compounds using the rat brain P2 preparation also show differences. (−)-Lobeline and (−)-anabasine, like the nicotinic antagonists mecamylamine and hexamethonium, bind predominantly to low affinity sites with KDs in the micromolar range whereas (−)-cytisine binds only to a single high affinity site with a KD in the nanomolar range. Further, the binding patterns of these drugs are different from (−)- and (+)-nicotine which bind to both high and low affinity sites but differ from each other in binding characteristics. Thus the binding data are consistent with the pharmacologic data in suggesting that the drugs have different modes of action and support the concept that the low affinity site has an important role in the central nervous system action of these compounds.
Genetic and comparative mapping of genes dysregulated in mouse hearts lacking the Hand2 transcription factor gene.

Abstract The helix-loop-helix transcription factor HAND2 plays a vital role in the development of the heart, limb, facies, and other neural crest-derived structures. We used differential display analysis to identify 33 putative HAND2-regulated ESTs that are differentially expressed in Hand2 −/− vs wild-type mice. We determined the positions on mouse and human genetic maps of 29 of these by using the T31 mouse Radiation Hybrid panel, comparison to human genomic sequence, and comparative mapping. We examined the conserved chromosomal locations for phenotypes that involve development of heart, face, and limb structures that are affected by HAND2. One EST mapped to a region of conserved synteny between mouse chromosome 2 and human chromosome 10p. RACE analysis extended the sequence and identified this cDNA as the mouse ortholog of human nebulette, an actin-binding protein expressed in fetal heart. Nebulette was shown to be deleted in DiGeorge Syndrome 2 patients with the proximal deletion of human 10p13–p14 that is associated with cardiac and craniofacial abnormalities.
Tricritical points of thin superconducting films

A similarity between the phase diagrams of systems which are believed to exhibit tricritical points and the phase diagram of the transition to the superconducting state of a thin film in a uniform magnetic field suggests the existence of a tricritical point in the latter system. The superconducting case is of interest because the field thermodynamically conjugate to the order parameter can be realized physically. The conjugate field plays an important role in models of the tricritical point but has been believed to be unphysical in systems studied thus far.
The social psychological consequences of emigration from Ireland for those who stay

Much of the research into emigration has investigated the causes of emigration and the acculturation experiences of emigrants as they adapt to their new homes. This qualitative study examined the social psychological consequences of emigration from Ireland for those who remain. Twenty individuals participated in in-depth interviews during which they responded to questions dealing with their response to the emigration of a close friend or relative. A content analysis of interview results indicated that respondents identified several reactions to the emigration, including sadness and grief. The results also revealed that the stayers compared themselves with their departed friend or relative. These comparisons and their consequences are interpreted in terms of equity theory.
Doubly stochastic matrices which have certain diagonals with constant sums

Abstract Let A be an n × n doubly stochastic matrix and suppose that 1⩽ m ⩽ n −1. Let τ 1 ,…,τ m be m mutually disjoint zero diagonals in A , and suppose that every diagonal of A disjoint from τ 1 ,…,τ m has a constant sum. Then aall entries of A off the m zero diagonals have the value ( n − m ) −1 . This verifies a conjecture of E.T. Wang.
Use of trout liver slices to enhance mechanistic interpretation of estrogen receptor binding for cost-effective prioritization of chemicals within large inventories.

The cost of testing chemicals as reproductive toxicants precludes the possibility of evaluating large chemical inventories without a robust strategy for prioritizing chemicals to test. The use of quantitative structure−activity relationships in early hazard identification is a cost-effective prioritization tool, but in the absence of systematic collection of interpretable test data upon which models are formulated, these techniques fall short of their intended use. An approach is presented for narrowing the focus of candidate ED chemicals using two in vitro assays: one optimized to measure the potential of chemicals to bind rainbow trout estrogen receptors (rtER), and a second to enhance interpretation of receptor binding data in a relevant biological system (i.e., fish liver tissue). Results of rtER competitive binding assays for 16 chemicals yielded calculable relative binding affinities (RBA) from 179 to 0.0006% for 13 chemicals and partial or no binding for an additional 3 chemicals. Eleven lower to ...
Automated verification of access control policies using a SAT solver

Managing access control policies in modern computer systems can be challenging and error-prone. Combining multiple disparate access policies can introduce unintended consequences. In this paper, we present a formal model for specifying access to resources, a model that encompasses the semantics of the xacml access control language. From this model we define several ordering relations on access control policies that can be used to automatically verify properties of the policies. We present a tool for automatically verifying these properties by translating these ordering relations to Boolean satisfiability problems and then applying a sat solver. Our experimental results demonstrate that automated verification of xacml policies is feasible using this approach.
A model for the pseudorotation of cycloheptane

Abstract A very simple model for a seven-membered ring having fixed bond lengths and fixed ring bond angles is presented. The model pseudorotates in both the twist-chair/chair and the twist-boat/boat conformations and gives reasonably accurate detailed geometries.
The interpretation of traces

This paper argues that parts of the lexical content of an A-bar moved phrase must be interpreted in the base position of movement. The argument is based on a study of deletion of a phrase that contains the base position of movement. I show that deletion licensing is sensitive to the content of the moved phrase. In this way, I corroborate and extend conclusions based on Condition C reconstruction by N. Chomsky and D. Fox. My result provides semantic evidence for the existence of traces and gives semantic content to the A/A-bar distinction.
Nonlinear spectroscopy in astronomy: assignement of diffuse interstellar absorption bands to L(α) -induced, two-photon absorption by H2 molecules

Abstract All (twelve) optical diffuse interstellar absorption bands appearing in the interval 768.0–788.0 nm are assigned on the basis of a nonlinear effect: Lyman-alpha-driven, resonantly enhanced two-photon absorption by hydrogen molecules located near H II regions of young, hot stars.
A Review of “Chica da Silva: A Brazilian Slave of the Eighteenth Century”

The story of Chica da Silva is by now well known to historians of colonial Brazil. The daughter of an enslaved African woman from the Coast of Mina and a Portuguese man who was a captain of militia...
Plasma measures of B-endorphin-like immunoreactivity in depressives and other psychiatric subjects

Abstract We report the utilization of a very sensitive radioimmunoassay for plasma B-END, which has enabled us to examine the suppressibility of B-END-like material, under dexamethasone challenge, on a population of depressed patients. We have found that B-END-like material in plasma is suppressed by dexamethasone in a psychiatric control population, whereas suppression is less likely in endogenously depressed patients. There also appears to be a dissociation between cortisol and B-END measures (tested at 4:00 PM) in the endogenously depressed group.
Computer Program for Printing Undeformed Fourier Maps

The program calculates the values of the function at those points where the computer can print them.