cssi/SciSciGPT-SciSciNet huggingface dataset:
Topographic Analysis of Auditory Event-Related Potentials

Publisher Summary This chapter discusses the topographic analysis of auditory event-related potentials (ERPs). The analysis of neural mechanisms underlying human auditory processes depends principally upon the study of scalp recorded potentials. These auditory event-related potentials (ERPs) reflect neural activity at all stages of auditory processing. As yet, however, the intracranial sources of the various auditory ERP components have not been conclusively identified. Knowledge of the anatomical locus of these generators is essential for interpretation of ERPs in terms of the neural processes that generate them, as well as providing a basis for linking psychological theories of auditory processing with neurophysiological mechanisms. Topographic studies of some of the more prominent auditory ERP components have been carried out. These data support the conclusion that the obligatory AEP components up to 200msec in latency are modality specific in topography and are consistent with sources principally within the superior temporal plane. Task-related components, a negativity at about 200 msec in peak latency (N2) and the later positive complex (LPC) exhibit different scalp distributions, with that of the former being modality specific and the latter being coextensive with LPC associated with visual stimuli.
Gender, Farming, and Long-Term Change: Maya Historical and Archaeological Perspectives

A reassessment of ethnographic, ethnohistoric, and archaeological evidence documents variation in Maya agricultural technologies across time and space and change in the social relations of farming alongside other social, political, and economic changes over 1,000 years of Maya history. This contradicts a timeless narrative of manthefarmer that can be derived from contemporary Yucatec Maya sources. An examination of engendered experiences in the Late Classic farming settlement of Chan Nohol in Belize demonstrates that the use of multiple lines of evidence to embody the archaeological record can help archaeologists to move beyond the tyrannical imposition of contemporary voices on a voiceless past.
Metabolism of Phosphatidylglycerol, Phosphatidylethanolamine, and Cardiolipin of Bacillus stearothermophilus

Abstract The total phospholipid content of Bacillus stearothermophilus was constant during exponential growth, increased during the transition from the exponential to stationary phase of growth, and then slowly increased during the stationary phase. The first increase was a result of an increase in phosphatidylethanolamine; the second was a result of an increase in cardiolipin. Cessation of aeration of an exponentially growing culture or suspension in a nongrowth medium resulted in an immediate reduction in the rate of total phospholipid and phosphatidylethanolamine synthesis and a quantitative conversion of phosphatidylglycerol to cardiolipin. Cardiolipin appeared to be synthesized by the direct conversion of two molecules of phosphatidylglycerol to cardiolipin. After a 20-min pulse of 32P, phosphatidylglycerol showed the most rapid loss of 32P followed by cardiolipin, whereas phosphatidylethanolamine did not lose 32P. The loss of 32P from the total lipid pool, phosphatidylglycerol, and cardiolipin was biphasic, with rapid loss during the first two bacterial doublings followed by a greatly reduced rate of loss. The major loss of 32P from the total phospholipid pool appeared to be by breakdown of cardiolipin. The loss of 32P from the lipid pool was energy dependent (i.e., did not occur under anaerobic conditions or in the absence of an energy source) and was dependent on some factor other than the concentration of cardiolipin in the cells. The apparent conversion of phosphatidylglycerol to cardiolipin was independent of energy metabolism. Chloramphenicol reduced the rate of turnover of both phosphatidylglycerol and cardiolipin. The rate of lipid synthesis (all phospholipid components) was constant for about 10 min after the addition of chloramphenicol but diminished markedly after 20 min. Turnover of 32P incorporated into phospholipid during a 30-min period prior to the addition of chloramphenicol was more rapid after the removal of chloramphenicol than that of 32P incorporated during a 30-min period in the presence of chloramphenicol.
Presentations and Bearers of Semantics on the Web

We use an example from information retrieval to explore Web-based semantics, which can be presented in different ways and carried by different bearers of the information retrieval process. We describe four presentations of semantics: natural language with minimal markup, simple metadata, basic data models, and logical semantics. Each presentation of semantics can be borne by human users, search interfaces, documents, or search systems. We show that different presentations of semantics vary across a spectrum of expressiveness and arbitrariness of meanings that are shared and processed during information retrieval.
Teachers' perceptions about children's movement and learning in early childhood education programmes

Background Efforts to improve the academic skills of preschool-aged children have resulted in approaches that tend to limit children's movement. However, movement experiences have long been considered important to children's learning and have received increased attention because of the obesity epidemic. Early childhood educators are important sources of information about if and how to promote learning and school readiness through movement, but little effort has been made to understand teachers' views on this topic. Methods We conducted six focus groups with 37 teachers from a Head Start programme with centres in three cities in eastern Pennsylvania. We inquired about: (1) how movement influences children's learning; (2) what types of movement experiences are most beneficial for children; (3) what settings best support children's movement; and (4) challenges related to children's movement. To identify key themes from the focus groups, transcripts were analysed using an inductive method of coding. Results Teachers' views were expressed in four major themes. First, young children have an innate need to move, and teachers respond to this need by using movement experiences to prepare children to learn and to teach academic concepts and spatial awareness. However, teachers wanted more training in these areas. Second, movement prepares children for school and for life by building children's confidence and social skills. Third, teachers and children benefit from moving together because it motivates children and promotes teacher–child relationships. Finally, moving outdoors promotes learning by engaging children's senses and promoting community interaction. Conclusions More training may be required to help early childhood educators use movement experiences to teach academic concepts and improve children's spatial awareness. Future interventions could examine the impacts on children's movement and learning of having teachers move with children during outdoor free play and including more natural features in the design of outdoor play areas.
Servicing seismic and oil reservoir simulation data through grid data services

This paper presents the implementation of a two layer infrastructure for servicing queries against large datasets generated in oil reservoir simulation studies in the Grid. The first layer implements object-relational virtualization of file-based dataset stored on a storage cluster. The second layer provides an implementation of Grid Data Services via Open Grid Services Architecture Data Access and Integration (OGSA-DAI) middleware.
SOLAR 2000: Office of Solar Energy Conversion strategy

Through SOLAR 2000, the US Department of Energy's (DOEs) Office of Solar Energy Conversion (OSEC) proposes a strategy to accelerate power sector adoption of biomass electric, photovoltaic, and solar thermal electric technologies. This strategy is based on a partnership with key groups in the field, including the US solar electric industry, regulators, and federal and state agencies. SOLAR 2000 will facilitate the development of the US industrial and technological base to provide proven world-class products for a range of electric sector needs, while concurrently conditioning users to enhance their ability to identify, evaluate, and adopt these technologies as they become viable for particular applications. >
Bounds on restoration quality using a priori information

A theoretical bound on the improvement possible due to knowledge of signal points, for the case of a Gaussian signal in Gaussian noise, has been calculated. Wiener and projections-onto-convex-sets restorations have been computed both with and without knowledge of the known points. The estimation errors are compared for different noise levels and blurs, and different numbers of known points. >
Effect of Serum Hyperosmolality on Opening of Blood-Brain Barrier for Bilirubin in Rat Brain

The effect of hyperosomolality on the blood-brain barrier for bilirubin was studied in rats. Hyperbilirubinemia was induced in the chronically catheterized rat by infusion of bilirubin at a rate of 30 mg/kg/h for three hours. After two hours of bilirubin infusion, three levels of hyperosmolality were induced by bolus of urea at three different doses: 50, 75, and 100 mmol/kg, respectively. The serum osmolality rose from 297 mosm/L in the control group to 345, 383, and 400 mosml/L in the three respective groups. No significant differences were found between the groups in levels of total or free serum bilirubin, serum albumin, blood pH, and blood gases. A significant dose relationship was found in both brain bilirubin and brain albumin content with reference to the serum hyperosmolality. The results indicate that hyperosmolality causes opening of the blood-brain barrier for bilirubin in the rat. It may be speculated that this adverse phenomenon (hyperosmolality) may play a role in the pathogenesis of kernicterus in infants whose serum bilirubin levels are below the range of saturated bilirubin binding capacity.
Microdetermination of Inorganic Phosphate, Phospholipids, and Total Phosphate in Biologic Materials

A rapid, reproducible, and sensitive procedure for the determination of phosphate in several biologic materials is described Organic phosphate is rapidly converted to orthophosphate by digestion with a nitric acid-calcium ion mixture. The acid destroys the organic material while the calcium ion prevents loss of phosphate or its conversion to an unmeasurable form. Inorganic phosphate can be determined in the presence of labile organic phosphates since phosphate liberated after the color reaction has been initiated cannot interfere by forming further color. Even if phosphate were deliberately added after the color reaction had started, it could not react in the described system. The method may be applied to the determination of phosphate present in ultramicro quantities. It is unnecessary to extract the heteropoly acid complex either to increase sensitivity or to protect the color complex formed from interference of phosphate hydrolyzed during the process of color formation.
Applications of coilgun electromagnetic propulsion technology

Exciting and important applications of pulsed power and high voltage technology are found in the growing area of electromagnetic launch and propulsion. These applications include small-scale, precision staging devices (magnetically driven), low-speed, large mass catapult launchers, low-speed and high-speed trains, high-speed, long-range fire support naval guns, and the futuristic application of high-speed, direct satellite launch to space. The force requirements range from a few Newtons to millions of Newtons, and the pulsed electrical power requirements range from kilowatts to gigawatts. For repetitive operation, the average prime power requirements range from a few watts to megawatts. The principal technical challenges for such propulsive devices and motors are achieving high thrust and high coil strength, producing and controlling high power levels, and maintaining good weight, volume, and efficiency characteristics. These challenges will be discussed, using coilgun mass launcher and pulsed linear induction motor technology examples. Basic parameters for a long-range fire support coilgun are a muzzle velocity of 2.0 to 2.5 km/s, with a projectile mass of 20 to 60 kg. The kinetic energy is thus around 100 to 200 MJ. To achieve the pulsed power needed for launch from a barrel of less than 20 m, peak coil voltages and currents on the order of 40 kV and 500 kA to 1 MA are needed. Train propulsion is somewhat lower in power demand. The kinetic power for a typical low-speed urban Maglev system would be in the range of 500 kW average power, driven by a power source of some 25 kV peak and 50 A peak. The added requirement of low weight and small volume power conditioning make this application challenging as well. The challenges and solutions for high-voltage power conditioning system designs are reviewed from these examples.
Anti-Tumor Effects of Endogenous Prostate Cancer Specific CD8 T Cells in a Murine TCR Transgenic Model

BACKGROUND The CD8 T-cell response to prostate and other cancers is often functionally diminished or absent. This may occur via deletion of tumor-specific T cells, through acquisition of an anergic phenotype, or via active suppression mediated by another population of cells. METHODS We used a double transgenic model in which mice express CD8 T cells specific for a prostate/prostate cancer antigen to study the response of CD8 T cells to evolving autochronous prostate tumors in TRAMP mice. CD8 T cells were analyzed for functionality by measuring IFN-γ production via flow cytometry and via an in vivo CTL killing assay. In addition, pathological scoring of the prostates of the double transgenic mice was compared to scoring of tumor burden prostates of ProTRAMP mice. RESULTS Tumor-specific CD8 T cells were not grossly deleted in these animals, but evidenced a clearly non-functional phenotype. Interestingly, full lytic function was rapidly recovered upon removal from tumor-bearing mice. CONCLUSIONS These data indicate a role for continuous antigen exposure in the maintenance of tumor-specific CD8 T-cell tolerance to prostate cancer. Prostate 72:514–522, 2012. © 2011 Wiley Periodicals, Inc.
Preference of the confused flour beetle for certain Penicillium isolates.

Whole wheat flour, autoclaved wheat flour and fungal cultured ( Penicillium spp) wheat flour were offered to Tribolium confusum adults in a choice chamber. Whole wheat flour was the preferred medium. No preference was shown for autoclaved wheat flour even over no flour at all. Behavioral responses of T. confusum to various isolates of Penicillium were compared to life history data for T. confusum from previously published feeding trials. In general, T. confusum was attracted to those fungal isolates with nutritional benefit and repelled by those containing growth inhibitors. One mycotoxin, citrinin, was repellent to T. confusum when offered in whole wheat flour.
Effectiveness of Vaginal Implant Transmitters for Locating Neonatal Mule Deer Fawns

Abstract We evaluated vaginal implant transmitters (VITs) as a technique for locating neonatal mule deer (Odocoileus hemionus) fawns. We implanted VITs in 29 pregnant, wild female mule deer in March 2003 and in 20 pregnant, captive mule deer in March 2004. We found no wild fawns at the birth site using VITs. Only 12 of 19 VITs were dropped in beds, and none could be confirmed as birth sites. In contrast, captive does shed 17 of 19 VITs at the birth site during parturition. Two were shed prematurely, and signals of 2 VITs failed. Antenna length, depth of insertion, and length of vaginal canal had no effect on the likelihood of premature shedding. Using aerial telemetry, we detected implanted VITs from distances of up to 1.2 km and expelled VITs from up to 2 km away, whereas from the ground, signal range was <0.6 km. Labor during fawning lasted an average of 121 min, and the average fawn began standing 35 min and nursing 43 min after birth. Six of 17 of captive females left the birth site within 6 hr of par...
Low-Dose Aspirin and Medical Record–Confirmed Age-related Macular Degeneration in a Randomized Trial of Women

Objective To test whether alternate-day low-dose aspirin affects incidence of age-related macular degeneration (AMD) in a large-scale randomized trial of women. Design Randomized, double-masked, placebo-controlled trial. Participants Thirty-nine thousand eight hundred seventy-six healthy female health professionals aged 45 years or older. Intervention Participants were assigned randomly to receive either 100 mg aspirin on alternate days or placebo and were followed up for the presence of AMD for an average of 10 years. Main Outcome Measures Incident AMD responsible for a reduction in best-corrected visual acuity to 20/30 or worse based on self-report confirmed by medical record review. Results After 10 years of treatment and follow-up, there were 111 cases of AMD in the aspirin group and 134 cases in the placebo group (hazard ratio, 0.82; 95% confidence interval, 0.64–1.06). Conclusions In a large-scale randomized trial of female health professionals with 10 years of treatment and follow-up, low-dose aspirin had no large beneficial or harmful effect on risk of AMD. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Evidence bearing on the construct validity of "ideal family size"

George Gallup polled "ideal family size" in 1936 and introduced a concept which subsequently appeared in many polls and fertility surveys. Previous research shows that ideal is a poor measure of respondent's personal fertility plans or behavior and that among researchers there is little agreement about what ideal family size does measure, if anything. Construct validity analysis based on historical, trend, and cross-sectional data suggests that the late 1960s saw ideal politicized as preoccupation with the "population problem" grew. Ideal family size is now appropriately regarded as a measure of a societal pronatalist norm and not merely a projected fertility preference.
Participation of the intracellular enzymes in the control of mutational processes : Part 4: the role of UV-specific endonuclease and medium composition in the induction of genic mutations in Escherichia coli.

The influence of UV-specific endonuclease and medium composition on the frequency and spectrum of genic mutations in Escherichia coli KI2 uvr + (with normal repair enzymes) and urv A6 (defective in UV-specific endonuclease) was studied. Mutations at the locus glu (gene controlling assimilation of glucose) were induced by ultra-violet irradiation and hydroxylamine treatment. To identify mutant colonies, triphenyl tetrazolium chloride (TTC) was added to the medium since it coloured the mutant colonies bright crimson and readily permitted distinction between pure mutant clones (complete mutations) and mixed clones (mosaic or sector mutations). A maximum mutation frequency after UV-irradiation was observed in E. coli uvr + cells but not in the E. coli uvr A6 strain. The curve of mutagenesis with a maximum was found in both studied strains after treatment by hydroxylamine which did not cause DNA damage recognized by UV-specific endonuclease. The highest frequency of mutations (at the point of maximum) in the series of experiments with enriched growth medium was almost 10 times higher than in the series of the experiments with poor medium. It was established that in bacteria with normal repair enzymes the frequency of complete mutations was higher than the frequency of mosaic mutations. It was also observed that the rate of UV-mutagenesis was higher in the case of E. coli uvr +. The study of the distribution of mosaic mutant sectors in experiments with bacteria suspended in either a nutrient broth or a buffer during UV-irradiation revealed that the size of mutant sectors was rather variable and that the differences in the number of nucleoids per cell did not always determine the distribution of mutant sector sizes.
Unraveling the Mystery of Erythropoietin-Stimulating Agents in Cancer Promotion.

Erythropoietin-stimulating agents (ESA) are approved for use in treating chemotherapy-induced anemia in patients with nonmyeloid malignancies. However, recent clinical trials have shown evidence of inferior overall survival and/or locoregional control of tumors in patients receiving ESAs. Given these concerning data, current studies are focused on elucidating the biological mechanisms by which ESAs may contribute to cancer promotion. Evidence suggests that ESAs activate several signaling pathways that are important in altering tumor behavior and response to treatment. Although further research is needed to more precisely elucidate these mechanisms, caution should be exercised in the use of ESAs beyond their approved indication in cancer patients. [Cancer Res 2008;68(11):4013–7]
State Estimation of a Simulated Turbine Generator

A model of a single steam turbine generator is developed which includes the effects of random load fluctuations observed in interconnected power systems. This model is used in the design of an on-line state estimator for an individual generator. A digital simulation of the generator model and state estimator indicates the state estimation procedure is feasible and can be implemented on a small control computer.
High-Resolution Differential Ion Mobility Separations Using Planar Analyzers at Elevated Dispersion Fields

The ion mobility spectrometry (IMS) methods are grouped into conventional IMS, based on the absolute ion mobility, and differential or field asymmetric waveform IMS (FAIMS), based on mobility differences between strong and weak electric fields. A key attraction of FAIMS is substantial orthogonality to mass spectrometry (MS). Although several FAIMS/MS platforms were commercialized, their utility was limited by FAIMS resolving power, typically ∼10−20. Recently, gas mixtures comprising up to 75% He have enabled resolving power >100 that permits separation of numerous heretofore “coeluting” isomers. This performance opens major new proteomic and other biological applications. Here, we show that raising the separation field by ∼35% over the previous 21 kV/cm provides similar or better resolution (with resolving powers of >200 for multiply charged peptides) using only 50% He, which avoids problems due to elevated pressure and He content in the mass spectrometer. The heating of ions by the separation field in th...
Observer study for evaluating potential utility of a super-high-resolution LCD in the detection of clustered microcalcifications on digital mammograms.

We evaluated the potential utility of a newly developed liquid-crystal display (LCD), which used an independent sub-pixel drive (ISD) technique for increasing the spatial resolution of a standard LCD three times in one direction, by use of receiver operating characteristic (ROC) analysis and a two-alternative-forced-choice (2AFC) method to determine improvement in radiologists’ accuracy in the detection of clustered microcalcifications (MCLs) on digital mammograms. We used a standard LCD without and with the ISD technique, which can increase the spatial resolution of the LCD three times in one direction from three mega- to nine megapixels without changes in the size of the display. We used 60 single views of digital mammograms (30 with and 30 without clustered MCLs) for ROC studies and 60 regions of interest (ROIs) with clustered MCLs for 2AFC studies. In the ROC study, seven radiologists attempted to detect clustered MCLs without and with the ISD on the same LCD. In the 2AFC study, the same observer group compared the visibility of MCLs by use of the LCD without and with the ISD. Our institutional review board approved the use of this database and the participation of radiologists in this study. The accuracy in detecting clustered MCLs in the ROC study was improved by use of the LCD with the ISD, but the improvement was not statistically significant (p = 0.08). However, the superiority of the LCD with the ISD was demonstrated as significant (p < 0.001) in the 2AFC study. An LCD with ISD can improve the visibility of clustered MCLs when high-resolution digital mammograms are available.
Influence of pyrrhotite on the corrosive wear of grinding balls in magnetite ore grinding

Abstract The influence of pyrrhotite on the corrosive wear of grinding balls in magnetite ore grinding was studied using three types of balls, namely, mild steel, high carbon low alloy (HCLA) steel and austenitic stainless steel under different aeration conditions. The results obtained through marked ball grinding tests were correlated with electrochemical measurements using magnetite, pyrrhotite and the respective ball material electrodes. In the absence of sulfide-bearing minerals such as pyrrhotite, corrosive wear of the grinding balls in the wet grinding of magnetite ore was relatively small, even in the presence of oxygen. The presence of pyrrhotite significantly increased the corrosive wear of mild steel and HCLA steel balls, especially in the presence of oxygen. No such increase in ball wear with pyrrhotite addition was observed with austenitic stainless steel balls. Electrochemical studies indicate that the corrosion of both mild steel and HCLA steel in mill water is accelerated in the presence of pyrrhotite.
IMMUNE STATUS AND IMMUNE RECOVERY IN CHILDREN WITH LYMPHOMA AT THE END OF THERAPY (CHEMOTHERAPY AND/OR RADIOTHERAPY) AND IN FOLLOW-UP EVALUATIONS

OBJECTIVE: We aimed to evaluate the immune status and immune recovery after completion of chemotherapy and/or radiotherapy in children with lymphoma. METHODS: We prospectively evaluated humoral and cellular immunity in 22 children with lymphoma (11 with Hodgkin9s disease [HD] and 11 with non-Hodgkin9s lymphoma [NHL]) at the completion of therapy and every 6 months thereafter. RESULTS: Immunoglobulin (Ig) levels were normal before the onset of therapy in all but 1 child. At the end of therapy, Ig levels decreased: IgM in 18, IgG in 12, and IgA in 7 children. In addition, 17 of 22 had decreased CD19 levels. In HD after radiotherapy, IgG and CD19 levels increased significantly (P = .013 and .004, respectively). IgM levels remained abnormally low in 16 of 22 children up to 18 months after therapy completion. At the end of therapy, helper T lymphocyte (CD4) levels were low in 20 of 22 children, and suppressor (CD8) levels were elevated in 13 of 22 children. (For those with HD before radiotherapy, the CD8 level was high in 10 of 11 children, and the CD4 level was low in 6 of 11 children.) The suppressor CD8 level remained elevated in 12 of 20 children, and helper CD4 level remained abnormally low in 18 of 20 children for a period of 6 to 18 months after therapy. Some immunized children became nonimmune to polio (15 of 22), mumps (6 of 22), rubella (5 of 22), and measles (1 of 22). CONCLUSIONS: In children with lymphoma, IgM levels remained low for long periods. Helper T lymphocyte levels were low and suppressor levels were high at the end of therapy. Suppressor cells normalized faster, whereas helper cell levels remained abnormally low for a long period. Most children became nonimmune to polio, whereas the majority had antibodies to measles, mumps, and rubella. Despite depressed immunity, serious infections were not documented.
Evolution of Languages, Consciousness and Cultures

The knowledge instinct is a fundamental mechanism of the mind that drives evolution of higher cognitive functions. Neural modeling fields and dynamic logic describe it mathematically and relate to language, concepts, emotions, and behavior. Perception and cognition, consciousness and unconsciousness, are described, while overcoming past mathematical difficulties of modeling intelligence. The two main aspects of the knowledge instinct determining evolution are differentiation and synthesis. Differentiation proceeds from and unconscious states to more crisp and conscious, from less knowledge to more knowledge; it separates concepts from emotions, Its main mechanism is language. Synthesis strives to achieve unity and meaning of knowledge; it is necessary for resolving contradictions, concentrating will and for purposeful actions. Synthesis connects language and cognition. Its main mechanisms are emotionality of languages and the hierarchy of the mind. Differentiation and synthesis are in complex relationship of symbiosis and opposition. This Leads to complex dynamics of evolution of consciousness and languages. Its mathematical modeling predicts evolution of cultures. We discuss existing evidence and future research directions.
Ca2+ transport systems mediating the high K+/low Na+-induced uptake of Ca2+ into rat atrium.

The effect of high K + /low Na + -Tyrode's solution on Ca 2+ uptake into neonatal rat atrium was studied using 45 Ca 2+ . Substitution of 60–129 m m Na + in Tyrode's solution by equimolar concentrations of K + or choline, significantly (with the exception of 60 m m choline substitution) increased Ca 2+ uptake above control. Furthermore, the Ca 2+ uptake stimulated by K + substitution was significantly greater than that stimulated by choline substitution at the corresponding concentration. The choline/low Na + -induced Ca 2+ uptake (i.e. that above the Ca 2+ uptake measured in normal Tyrode's solution) was increased by pre-exposure to either ice-cold Tyrode's solution for 1 h (∼36% increase) or to K + -free Tyrode's solution for 3 h (∼100% increase). The choline/low Na + -induced Ca 2+ uptake was abolished by the hypertonic addition of NaCl (returning the bathing Na + concentration to normal), increased (∼140%) by the addition of 1.8 m m PO 4 3− to HCO 3 − /PO 4 3− -free Hepes buffered choline/low Na + media, but unaffected by 0.2 m m cadmium. The high K + /low Na + -induced Ca 2+ uptake (i.e. that above the Ca 2+ uptake measured in normal Tyrode's solution) was relatively insensitive to pre-exposure to cold (0% change) or K + -free media (11% increase) and only 50% inhibited by the hypertonic addition of NaCl (returning the bathing Na + concentration to normal). However, the high K + /low Na + -induced Ca 2+ uptake was 57% inhibited by 0.2 m m cadmium and approximately 30% inhibited by the addition, of 1.8 m m PO 4 3− to HCO 3 − /PO 4 3− -free Hepes buffered high K + /low Na + media. Moreover, the high K + /low Na + -induced Ca 2+ uptake was significantly greater than resting Ca 2+ uptake even after prolonged (10 min) exposure to high K + /low Na + solution. In addition, the high K + /low Na + flux was neither inhibited by 5×10 −6 m diltiazem nor augmented by 10 −6 m isoproterenol. It is concluded that the Ca 2+ uptake measured in high K + /low Na + solution is mediated by a minimum of two mechanisms.
Molecular adaptations to the diving habit: on the possible role of glycerol in the ischemic seal kidney

Abstract 1. 1. Isolated perfused kidneys of the spotted seal (Phoca vitulina richardsi) are able to withstand long periods of ischemia and resultant anoxia. In this state the major source of energy of the kidney cortex appears to be glycogen, wich is converted stoichiometrically to lactate. 2. 2. After about 45 min of ischemia glycogen stores in kidney cortex are effectively depleted: yet lactate concentrations continue to rise, albeit at a lower rate. 3. 3. On the basis of an observed rapid increase in concentrations of the free fatty acids in the tissue, the source of this additional lactate is glycerol from triglycerides within the tissue. 4. 4. When seal kidney, which is ischemic during the dive, is compared to seal heart, which is perfused during the dive, the activities of the enzymes glycerokinase, α-glycerophosphate dehydrogenase and triosephosphate isomerase are substantially higher in seal kidney cortex than in seal heart, or kidney of the domestic dog. 5. 5. This suggests the existence of a short metabolic sequence that can augment the finite stores of carbohydrate in this usually active tissue during a long and arduous dive. 6. 6. This sequence does not become active until glycogen stores are virtually depleted and the kidney cortex cell's energy charge is much reduced (from 0.84 to 0.71). 7. 7. These results suggest the existence of a late metabolic “reserve” for an ischemic tissue of the diver during a particularly strenuous or long dive.
Economic Theory and the Political Scientist

ANY valid piece of economic analysis is, of course, potentially interesting to the political scientist, just as his results are of interest to the economist. However, especially since the time when "economics" superseded "political economy" as standard nomenclature, most of the economist's work has been kept "pure" of direct political application. Many of his theorems are essentially designed to be descriptive and their implications either for policy or for political theory are seldom stressedindeed, they are sometimes not even discernible. Nevertheless, some lines of economic thought have produced, or sought to produce, results which are of direct interest to the political scientist. Some of this work seems to have landed in the border territories which separate the two disciplines. Noteworthy in this respect is the field of welfare economics. In it are examined the effects of economic actions and decisions on the welfare of the individuals who compose the economy or, more generally, on the welfare of any group to which the analyst chooses to direct his attention. In short, it might be described as the theory of economic policy. In practice, work in welfare economics has been considerably narrower than this suggests, but at least some of it has been produced in this spirit, being concerned primarily with the composition of output-the amounts produced of each of the different commodities. The effects on output composition of the price mechanism, of the presence of monopolistic elements, and of different policies for the operation of nationalized industries have been examined and evaluated in terms of the preferences of the public. In other words, these economic forms have been considered as control
Measurements on the Diffusion Coefficient of Colloidal Particles by Taylor–Aris Dispersion

Abstract Taylor–Aris dispersion in narrow-bore capillaries is used to measure the diffusion coefficient of colloidal particles in aqueous suspension. The method is shown to yield accurate results for particles up to about 0.3 μm in diameter; the measurement time for larger particles is prohibitively long and impractical. For hydrophobic particles, interactions with the capillary walls can introduce error into the interpretation of the data. The measurements also suggest that buoyancy-driven particle motion can introduce error. Consequently, a method similar to capillary hydrodynamic fractionation was developed to establish when these factors were of negligible effect. The results constitute an order-and-a-half improvement in the sensitivity of the technique, which has been recently shown to work for nanometer-sized proteins. The data suggest that, when matched with the appropriate theory, dispersion in capillaries may be a useful probe of colloidal and gravitational interaction potentials.
A National Study of Violent Behavior in Persons With Schizophrenia

Context Violent behavior is uncommon, yet problematic, among schizophrenia patients. The complex effects of clinical, interpersonal, and social-environmental risk factors for violence in this population are poorly understood. Objective To examine the prevalence and correlates of violence among schizophrenia patients living in the community by developing multivariable statistical models to assess the net effects of psychotic symptoms and other risk factors for minor and serious violence. Design A total of 1410 schizophrenia patients were clinically assessed and interviewed about violent behavior in the past 6 months. Data comprise baseline assessments of patients enrolled in the National Institute of Mental Health Clinical Antipsychotic Trials of Intervention Effectiveness. Setting and Patients Adult patients diagnosed as having schizophrenia were enrolled from 56 sites in the United States, including academic medical centers and community providers. Main Outcome Measures Violence was classified at 2 severity levels: minor violence, corresponding to simple assault without injury or weapon use; and serious violence, corresponding to assault resulting in injury or involving use of a lethal weapon, threat with a lethal weapon in hand, or sexual assault. A composite measure of any violence was also analyzed. Results The 6-month prevalence of any violence was 19.1%, with 3.6% of participants reporting serious violent behavior. Distinct, but overlapping, sets of risk factors were associated with minor and serious violence. “Positive” psychotic symptoms, such as persecutory ideation, increased the risk of minor and serious violence, while “negative” psychotic symptoms, such as social withdrawal, lowered the risk of serious violence. Minor violence was associated with co-occurring substance abuse and interpersonal and social factors. Serious violence was associated with psychotic and depressive symptoms, childhood conduct problems, and victimization. Conclusions Particular clusters of symptoms may increase or decrease violence risk in schizophrenia patients. Violence risk assessment and management in community-based treatment should focus on combinations of clinical and nonclinical risk factors.
Sonographically guided thoracentesis and rate of pneumothorax

Purpose To assess whether thoracenteses performed with sonographic guidance are associated with a lower rater of pneumothorax and tube thoracostomy than those performed without sonographic guidance. Methods We reviewed the medical records of 523 subjects undergoing their initial diagnostic thoracentesis at our institution from July 1, 2001, to June 30, 2002. We excluded 73 subjects in whom no chest imaging had been performed within 5 days of thoracentesis or who had pre-existing chronic hydropneumothorax. Results Of the 450 thoracenteses performed, 305 (67.8%) were performed with sonographic guidance and 145 (32.2%) were performed without. On postthoracentesis imaging in all subjects, 30 pneumothoraces (6.7%) were found (23 inpatients, 7 out-patients). Eight patients required a tube thoracostomy for their pneumothorax. Pneumothorax occurred in 15 of 305 procedures (4.9%) performed with sonographic guidance and 15 of 145 procedures (10.3%) performed without (p < 0.05). Tube thoracostomy was performed in 0.7% of patients whose thoracentesis was performed with sonographic guidance and in 4.1% in those that were not (p < 0.05). We found no correlation between pneumothorax after thoracentesis and age, inpatient status, loculation of effusion, or volume of pleural fluid removed. Conclusions The routine use of sonography during diagnostic thoracentesis is associated with a reduced rate of pneumothorax and tube thoracostomy. © 2005 Wiley Periodicals, Inc. J Clin Ultrasound33:442–446, 2005
Exact and approximate eigenvalues and intrinsic functions for the Gaussian chain theory

Abstract Eigenvalues for the Gaussian chain theory for dilute solutions of linear polymers have been determined in an exact manner for chain segments up to 100 and for a wide range of hydrodynamic interaction. It is found that these exact results may be closely approximated by a simple equation. The intrinsic functions of the eigenvalues which describe the molecular weight dependence of the intrinsic viscosity and terminal relaxation time of the chain are presented using both the exact and the approximate eigenvalues. It is shown that by using the simple approximate calculation good results are easily determined. The approximate equation is available for manipulation and analysis of complex eigenvalue functions.
High dose rate versus low dose rate brachytherapy for gynecological cancer

High dose rate (HDR) remote afterloading for the treatment of gynecologic cancers began about 30 years ago. The promising clinical results obtained have led to the establishment of hundreds of HDR facilities worldwide with tens of thousands of patients treated. Unfortunately, there has never been a randomized prospective clinical trial with sufficient patients to adequately compare results obtained with HDR and conventional low dose rate (LDR). However, there have been several dozen nonrandomized studies. For cervical cancer, with over 10,000 patients treated with each modality, these studies show that mean 5-year survival rates obtained with HDR are slightly better (61.1%) than with LDR (56.4%), and that these HDR results compare favorably with the best 5-year survival rates reported for LDR (61.6%). P values for these comparisons are not appropriate because of the nonrandomized nature of these studies. As far as severe complications are concerned, HDR appears to be significantly better than LDR (2.6% v 6.2%). Nonrandomized studies to compare HDR with LDR for endometrial cancer have been fewer; with over 1,000 patients treated by each technique, 5-year survival rates for HDR are better than for LDR (81% v 73%), and severe complication rates are slightly lower (1.0% v 1.4%). Because radiobiological principles would seem to favor LDR over HDR, unless a large number of HDR fractions are used, it is postulated that it is the "physics" of HDR that makes it work, not the "biology".
Aldolase-Catalyzed Synthesis of β-d-Galp-(1→9)-d-KDN: A Novel Acceptor for Sialyltransferases

[reaction: see text] beta-D-Galp-(1-->9)-D-KDN, a disaccharide component of the cell wall of Streptomyces sp. MB-8, was synthesized from beta-D-Galp-(1-->6)-D-Manp and pyruvate using a sialic acid aldolase. The obtained KDN-containing compound was a novel acceptor for bacterial sialyltransferases. Unusual alpha2,3- and alpha2,6-linked sialyltrisaccharides and a tetrasaccharide were synthesized using a one-pot two-enzyme system containing a Neisseria meningitidis CMP-sialic acid synthetase and a Pasteurella multocida sialyltransferase or a Photobacterium damsela alpha2,6-sialyltransferase.
NESTEDNESS OF REMNANT SONORAN DESERT PLANT COMMUNITIES IN METROPOLITAN PHOENIX, ARIZONA

Urbanization can have profound effects on the plant communities persisting in remnant habitats. That process can be explored by examining patterns of nestedness. Species composition for a set of communities exhibits a nested pattern if species present in progressively richer assemblages form a series of subsets. Nestedness can form as a result of the dynamic processes of extinction or colonization. It can also reflect a nested distribution of habitats among the sites or the differential abundance properties of species through passive sampling. This study investigated whether Sonoran Desert woody vegetation in remnant islands within metropolitan Phoenix is nested and explored which mechanisms are responsible for the pattern. It also examined whether vegetation is nested in similar habitat types across islands, and how species abundance relates to the nested pattern and hypothesized mechanisms. All data sets were significantly nested, indicating a nested pattern at the island and habitat levels. Community-level analyses did not indicate a primary mechanism leading to the nested pattern. Among species with abundances correlated with the nested rank-order of sites, abundance properties were significantly related to different variables. This suggests that individual taxa respond to divergent ecological mechanisms, leading to nestedness. Thus, nestedness in plant communities can result from a complex set of contributors and may not be attributable to a single factor.
Neuronal activity evoked in cat precruciate cerebral cortex by cutaneous stimulation

Abstract Extracellular recordings were made of the evoked activity of neurons in the precruciate forepaw cortex of the domestic cat after cutaneous stimulation of each limb. Neurons were classified according to the size of their excitatory receptive fields and whether or not their axons traversed the medullary pyramids. Neurons having bilateral receptive fields confined to the forelimbs and thoracic trunk region comprised 25% of the sample of 690 neurons; by contrast, only 6% of 1020 neurons from postcruciate arm cortex (gathered in a previous study) showed such fields. These neurons discharged with a short latency after stimulation of precruciate arm cortex of the opposite hemisphere; most other wide-field neurons but few small-field neurons responded to such interhemispheric activation. Many of the wide-field neurons responded to light or sound stimulation, or both, whereas few of the small-field neurons, including those with bilateral fields confined to the forelimb region, responded to such stimulation. Many wide-field neurons responded both to light touch and to hair-bending. Most pyramidal tract neurons had wide receptive fields. We concluded that the corticofugal elements in precruciate tissue receive information from cutaneous receptors of various types, distributed widely over the body surface, and that many of these elements are influenced by several modalities of sensory input. The “interneurons” of precruciate cortex, on the other hand, have sharply restricted input channels, and provide the most immediate and powerful modulation of corticofugal elements.
Early‐phase ERK activation as a biomarker for metabolic status in fragile X syndrome

Lack of production of the Fragile X Mental Retardation Protein (FMRP) leads to changes in dendritic morphology and resultant cognitive and behavioral manifestations characteristic of individuals with Fragile X syndrome (FXS). FMRP is an RNA-binding protein that is believed to regulate the translation of a large number (probably over 100) of other proteins, leading to a complex and variable set of symptoms in FXS. In a mouse model of FXS, we previously observed delayed initiation of synaptically localized protein synthesis in response to neurotransmitter stimulation, as compared to wild-type mice. We now likewise have observed delayed early-phase phosphorylation of extracellular-signal regulated kinase (ERK), a nodal point for cell signaling cascades, in both neurons and thymocytes of fmr-1 KO mice. We further report that early-phase kinetics of ERK activation in lymphocytes from human peripheral blood is delayed in a cohort of individuals with FXS, relative to normlal controls, suggesting a potential biomarker to measure metabolic status of disease for individuals with FXS.
Hypermutation in human cancer genomes: footprints and mechanisms

Recent analyses of cancer genomes have revealed the occurrence of mutation patterns, which indicate their source. This Review discusses what we have learned, and what is yet to learn, from these data and how our current understanding of cancer mutations fits into our understanding of tumorigenesis and tumour progression.