cssi/SciSciGPT-SciSciNet huggingface dataset:
Closures and Dichotomies for Quantified Constraints

Quantified constraint satisfaction is the generalization of con- straint satisfaction that allows for both universal and existential quantifiers over constrained variables, instead of just existential quantifiers. We study quantified constraint satisfaction problems CSP(Q,S), where Q denotes a pattern of quantifier alternation ending in exists or the set of all possible alternations of quantifiers, and S is a set of relations constraining the com- binations of values that the variables may take. These problems belong to the corresponding level of the polynomial hierarchy or in PSPACE, depend- ing on whether Q is a fixed pattern of quantifier alternation or the set of all possible alternations of quantifiers. We also introduce and study the quan- tified constraint satisfaction problems CSP 0 (Q,S) in which the universally quantified variables are restricted to range over given subsets of the domain. We first show that CSP(Q,S) and CSP 0 (Q,S) are polynomial-time equiv- alent to the problem of evaluating certain syntactically restricted monadic second-order formulas on finite structures. After this, we establish three broad sufficient conditions for polynomial-time solvability of CSP 0 (Q,S) that are based on closure functions; these results generalize and extend earlier results by other researchers about polynomial-time solvability of CSP(Q,S). Our study culminates with a dichotomy theorem for the com- plexity of list CSP 0 (Q,S), that is, CSP 0 (Q,S) where the relations of S include every subset of the domain of S. Specifically, list CSP 0 (Q,S) is ei- ther solvable in polynomial-time or complete for the corresponding level of the polynomial hierarchy, if Q is a fixed pattern of quantifier alternation (or PSPACE-complete if Q is the set of all possible alternations of quantifiers). The proofs are based on a more general unique sink property formulation.
Thermal Performance of Stirling-Cycle Cryocoolers: A Comparison of JPL-Tested Coolers

Spacecraft cryocoolers continue to attract interest in the space science community. To date, many Stirling cycle cryocoolers have been characterized by JPL in a number of performance areas including thermal performance. A number of factors are used to evaluate the efficiency and cooling power of cryocoolers at cryogenic coldtip temperatures. A comparison of the measured thermal performance of several cryocoolers is presented.
The High Prevalence of Undiagnosed Prostate Cancer at Autopsy: Implications for Epidemiology and Treatment of Prostate Cancer in the Prostate-Specific Antigen-Era

Widespread prostate-specific antigen (PSA) screening detects many cancers that would have otherwise gone undiagnosed. To estimate the prevalence of unsuspected prostate cancer, we reviewed 19 studies of prostate cancer discovered at autopsy among 6,024 men. Among men aged 70-79, tumor was found in 36% of Caucasians and 51% of African-Americans. This enormous prevalence, coupled with the high sensitivity of PSA screening, has led to the marked increase in the apparent incidence of prostate cancer. The impact of PSA screening on clinical practice is well-recognized, but its effect on epidemiologic research is less appreciated. Before screening, a larger proportion of incident prostate cancers had lethal potential and were diagnosed at advanced stage. However, in the PSA era, overall incident prostate cancer mainly is indolent disease, and often reflects the propensity to be screened and biopsied. Studies must therefore focus on cancers with lethal potential, and include long follow-up to accommodate the lead time induced by screening. Moreover, risk factor patterns differ markedly for potentially lethal and indolent disease, suggesting separate etiologies and distinct disease entities. Studies of total incident or indolent prostate cancer are of limited clinical utility, and the main focus of research should be on prostate cancers of lethal potential.
Comparison study of DC- DC-AC combined converters for integrated starter generator applications

This paper presents comparative studies among three DC-DC-AC combined converters for integrated starter generator (ISG) applications. The necessity of using DC-DC-AC combined converter to achieve optimal performance of an ISG system is explained. Analysis and computer simulation of the three DC-DC-AC candidates is conducted to illustrate their respective advantages and disadvantages.
An instrumented system for measuring seated stability in children

An instrumented chair sized for the pediatric population has been constructed and calibrated. Its purpose is to provide reliable data describing changes in the seated stability of children with lower limb spasticity. >
Hysteresis of contact angle of water on paraffin. Effect of surface roughness and of purity of paraffin

Abstract The experimental results show that when very thin films of purified paraffin were formed in vacuum by volatilization on smooth glass surfaces and water drops were placed upon them, the advancing and the receding contact angles were sensibly the same, 112°; that is, hysteresis effects did not exist on these very thin and very smooth surfaces. Measurable hysteresis effects from 5° to 35° were found for less smooth films, and coatings of appreciable thickness formed in vacuum, in nitrogen, or in air, whether from a melt or by volatilization. The magnitude of the hysteresis effects appeared to be closely associated with the microscopic roughness of the surfaces, the roughness adding to the magnitude of the advancing angle but subtracting from the receding angle to the same degree, so that the average angle remained the same for paraffin films of different roughnesses but of the same degree of purification. The average contact angle for purified paraffin was slightly larger than the average angle for unpurified paraffin.
Letter: Effects of tobacco excise taxes on the use of smokeless tobacco products in the USA

Data from the September 1985 Current Population Survey are used to estimate the effects of tobacco excise taxes and state laws restricting smoking in public places on the likelihood of current use of cigarettes or smokeless tobacco (ST) products (moist snuff or chewing tobacco) among males in the USA. The results indicate that higher ST excise tax rates are associated with a reduced probability of ST use, whereas higher cigarette excise tax rates are associated with an increased probability of ST use, holding other factors constant. State laws restricting smoking have no apparent effect on ST use. © 1997 John Wiley & Sons, Ltd.
Effects of homogenization pressure and stabilizers on some physical characteristics of a beverage prepared from partially defatted, roasted peanuts

A low-fat beverage with roasted peanut flavor was developed from peanuts. The potential milk substitute contained 11.8% total solids, 2.0% fat and 3.7% protein, and was whitish orange-yellow in color. The effects of stabilizing additives and homogenization pressure (13.8×106 Pa or 41.4×106 Pa) on selected physical characteristics were determined. Suspension stability was improved by addition of carrageenan [Benlacta CM61-B (CM), 0.02–0.04%] or a hydrogenated mono- and diglyceride [Emuldan HV52K (HV, 0.2–0.4%)]. Homogenizing at 41.4×106 Pa increased viscosity of all samples except that of the controls but did not improve the suspension stability (top:bottom solids) of the beverage. The most viscous formulations (17.5±0.95 cps) were those containing 0.04% CM. Treatments yielding the best combination, compared to cow's milk values, of high suspension stability (0.5±0.03, where 1.0=maximum stability) and low viscosity (3.7±0.89 cps) were those containing 0.2% HV which were homogenized at 13.8×106 Pa.
Nifedipine versus fosinopril in uninephrectomized diabetic rats.

Nifedipine versus fosinopril in uninephrectomized diabetic rats. Antihypertensive agents have been shown to exert inequivalent effects on glomerular injury in experimental renal disease models. To compare the consequences of dissimilar antihypertensive regimens on the development of diabetic glomerulopathy, studies were performed in three groups of uninephrectomized moderately hyperglycemic diabetic rats. One group (DM) received no therapy except insulin. The remaining groups received insulin and either the angiotensin I converting enzyme inhibitor, fosinopril (FOS), or the calcium channel blocker, nifedipine (NIF). Both drugs lowered blood pressure comparably. At four to eight weeks, DM rats exhibited elevation of the single nephron glomerular filtration rate (SNGFR), due to elevations of the glomerular capillary plasma flow rate (Q A ) and the glomerular capillary hydraulic pressure (P GC ). Neither NIF nor FOS affected values for SNGFR or Q A . However, while FOS lowered P GC and increased K f , NIF did not affect these parameters. In longer term (8 month) studies, DM rats exhibited progressive albuminuria and glomerular sclerosis. FOS markedly limited development of albuminuria and glomerular injury, but NIF was ineffective in limiting either parameter of glomerular injury. Thus, in contrast to the beneficial effects of converting enzyme inhibitors, chronic calcium channel blockade with nifedipine fails to limit P GC glomerular injury in diabetic rats. These findings lend further support to the concept that different classes of antihypertensive agents are not equally effective in protecting against diabetic glomerulopathy.
GROWTH HORMONE GENE MUTATIONS IN PATIENTS WITH SHORT STATURE. 505

Short stature is associated with abnormalities of the growth hormone (GH) axis. We hypothesized that an aberrant, less functional, GH molecule due to a growth hormone gene (GH-I) mutation may lead to short stature due to abnormal secretory dynamics or abnormal interaction with the GH receptor. Genomic DNAs from patients (n = 130) with short stature (height < 2 S.D. below mean for age) and normal statured subjects (n = 108) were screened for abnormalities in the coding region of GH-I. The coding region was amplified from genomic DNA by polymerase chain reaction, and assayed by solution hybridization/nuclease protection. Five patients with short stature were identified with point mutations of GH-I in exon 2 compared to none in the normal statured group (p = 0.048). On Southern blotting, the mutation in all five patients created a new HincII restriction site, as evidenced by disappearance of the expected 6.6 Kb band in 3 of 5 patients and appearance of a new 4.5 Kb band in all 5 patients. The exact nature of these mutations will be characterized and studied for their biological activity. The assay described here identifies GH-I mutations in children with short stature which may impact GH function.
Patterns of Invertebrate Distribution and Abundance in the Intertidal Salt Marsh: Causes and Questions

The intertidal marsh community comprises both benthic and natant faunal components. The benthic components are primarily small invertebrates residing within or on the soft sediments of the vegetated marsh surface. The natant components include larger, fully aquatic organisms (e.g., fish and shrimp) that inhabit the shallow waters adjacent to the marsh at low tide but interact with the benthic components of the community when the marsh is tidally inundated. In this structurally complex and often expansive intertidal environment, patterns of invertebrate distribution and abundance are not apparent to the casual observer. Benthic core samples taken along an intertidal marsh transect on Sapelo Island, Georgia, USA show that many of the inconspicuous infaunal organisms, which numerically dominate the macrofaunal elements of this soft-substrate community, exhibit zonal distribution patterns along a tidal gradient. Patterns of invertebrate distribution in the intertidal salt marsh are often attributed to the activities of aquatic predators. The results of most predator exclusion experiments have left little doubt that predation/disturbance can be an important determinant of invertebrate abundance in soft-substrate communities; but a growing number of experiments, in both freshwater and marine environments, have produced results that apparently conflict with this, general tenet. Dismissed by some as “failed” experiments, these investigations have exposed our lack of knowledge about the effects of specific predators and the importance of complex interactions which involve more than two trophic levels. Although the importance of predation has been stressed in many recent experimental investigations, there are many other factors that, alone or in combination, may also influence the structure of salt marsh invertebrate assemblages. Included among these are: (1) various density-dependent processes (e.g., adult-larval interactions, agonistic behavior, interspecific competition), (2) selective larval settlement or mortality, (3) the influence of physical factors expressed through habitat preferences, and (4) unpredictable or cyclic physical disturbances. Many questions concerning the spatial and temporal patterns of invertebrate distribution and abundance in the salt marsh are unresolved and remain as challenges to our understanding of soft-substrate community dynamics.
Multi-label Collective Classification Using Adaptive Neighborhoods

Multi-label learning in graph-based relational data has gained popularity in recent years due to the increasingly complex structures of real world applications. Collective Classification deals with the simultaneous classification of neighboring instances in relational data, until a convergence criterion is reached. The rationale behind collective classification stems from the fact that an entity in a network (or relational data) is most likely influenced by the neighboring entities, and can be classified accordingly, based on the class assignment of the neighbors. Although extensive work has been done on collective classification of single labeled data, the domain of multi-labeled relational data has not been sufficiently explored. In this paper, we propose a neighborhood ranking method for multi-label classification, which can be further used in the Multi-label Collective Classification framework. We test our methods on real world datasets and also discuss the relevance of our approach for other multi-labeled relational data. Our experimental results show that the use of ranking in neighborhood selection for collective classification improves the performance of the classifier.
X-ray third-harmonic generation in plasmas of alkalilike ions

We demonstrate theoretically the feasibility of x-ray near-resonant third-harmonic generation in a number of plasmas of Li- and Na-like ions as well as third-harmonic generation enhanced by phase matching using buffer plasmas.
Robustness of controlled quantum dynamics

The control of multilevel quantum systems is sensitive to implementation errors in the control field and uncertainties associated with system Hamiltonian parameters. A small variation in the control field spectrum or the system Hamiltonian can cause an otherwise optimal field to deviate from controlling desired quantum state transitions and reaching a particular objective. An accurate analysis of robustness is thus essential in understanding and achieving model-based quantum control, such as in the control of chemical reactions based on ab initio or experimental estimates of the molecular Hamiltonian. In this paper, theoretical foundations for quantum control robustness analysis are presented from both a distributional perspective---in terms of moments of the transition amplitude, interferences, and transition probability---and a worst-case perspective. Based on this theory, analytical expressions and a computationally efficient method for determining the robustness of coherently controlled quantum dynamics are derived. The robustness analysis reveals that there generally exists a set of control pathways that are more resistant to destructive interferences in the presence of control field and system parameter uncertainty. These robust pathways interfere and combine to yield a relatively accurate transition amplitude and high transition probability when uncertainty is present.
Electronics: Power surfing on waves

Wavy strips of piezoelectric materials on stretchable substrates can both withstand larger applied mechanical strain without cracking and harvest energy more efficiently than their flat counterparts.
Informal institutions, shareholder coalitions, and principal–principal conflicts

How do informal institutions affect conflicts between controlling and minority shareholders, also known as principal–principal (PP) conflicts? The dominant formal institution-based view of corporate governance suggests that legal rules and regulations are crucial for the protection of shareholder rights. While this perspective has significantly advances our understanding of international corporate governance, we suggest that more attention to informal institutions may complement the formal approach. First, we utilize social identity theory to shed light on the formation of shareholder coalitions. Second, we draw on research involving informal institutions such as culture and trust to better understand PP conflicts. Overall, we extend the growing literature on PP conflicts by an explicit focus on informal institutions.
Grades, Course Evaluations, and Academic Incentives

We develop a model that identifies a range of new and somewhat counterintuitive results about how the incentives created by academic institutions affect student and faculty behavior. The model provides a theoretical basis for grade inflation and the behavioral response of students. Comparative statics are used to analyze the effects of institutional expectations placed on faculty. The results show that placing more emphasis on course evaluations exacerbates the problems of grade inflation and can even decrease a professor's teaching effort. Increased emphasis on research productivity also decreases teaching effort and provides a further incentive to inflate grades. We use the model to analyze how grade targets can control grade inflation and align professorial incentives with institutional objectives. We also discuss the implications of the model for hiring, promotion, and tenure.
Temperature dependence of the Schottky-barrier height of tungsten on n-type and p-type silicon

Abstract The Schottky-barrier heights of W and its silicide WSi2 on both n-type and p-type Si(100) have been measured in the temperature range 77–295 K with the use of current-voltage and capacitance-voltage techniques. Auger-electron and X-ray photoemission spectroscopies were used to characterize the Si(100) surfaces prior to metal deposition, and to monitor the reaction between W and Si. Silicide formation has very little or no effect on both the barrier height and its temperature dependence. The n-type barrier height for both the metal and the reacted silicide phase decreases with increasing temperature with a coefficient almost equal to the temperature coefficient of the indirect band gap in Si. The p-type barrier height does not exhibit a temperature dependence. These results suggest that the Fermi level at the interface is pinned relative to the valence-band edge. These results deviate from the predictions of models of Schottky-barrier formation based on the suggestion of Fermi-level pinning in the center of the semiconductor indirect band gap. Along with results previously reported for metal(silicide)-Si systems with a wide range in metal electronegativity, the present results show that both the silicon barrier height and its temperature dependence are affected by the metal.
19-Nor-1α,25-dihydroxyvitamin D2 (paricalcitol) exerts anticancer activity against HL-60 cells in vitro at clinically achievable concentrations ☆

Abstract 19-Nor-1α,25-dihydroxyvitamin D 2 (paricalcitol) is an analogue of 1,25(OH) 2 D 3 with reduced calcemic effects that is approved in the United States for the suppression of parathyroid hormone in chronic renal failure. Paricalcitol has anticancer activity in prostate cancer cells. We tested the effects of paricalcitol on the HL-60 leukemia cells, studying cellular differentiation, cell cycle changes, apoptosis and cellular proliferation. Paricalcitol at 10 −8 M concentration induced the maturation of HL-60 cells in a time-dependent manner, as shown by increased expression of CD11b differentiation surface antigen. The ability of HL-60 cells to reduce nitroblue tetrazolium (NBT) was markedly increased after exposure to paricalcitol at 10 −8 M for 72 h. Paricalcitol inhibited colony formation of HL-60 cells in a soft agar semisolid media after 10-day incubation (estimated IC 50 of 5×10 −9 M. Exposure to 10 −8 M paricalcitol for 72 h increased the number of cells in G 0 /G 1 phase, and decreased the number of cells in S phase, and significantly increased the number of HL-60 cells undergoing apoptosis. The concentration required to achieve inhibition of growth of HL-60 cells is comparable to clinically achievable levels. These findings support the clinical evaluation of paricalcitol as an antileukemia agent.
Automatic Creation of Object Hierarchies for Ray Tracing

Intersection calculations dominate the run time of canonical ray tracers. A common algorithm to reduce the number of intersection tests required is the intersection of rays with a tree of extents, rather than the whole database of objects. A shortcoming of this method is that these trees are difficult to generate. Additionally, manually generated trees can be poor, greatly reducing the run-time improvement available. We present methods for evaluation of these trees in approximate number of intersection calculations required and for automatic generation of good trees. These methods run in O(nlogn) expected time where n is the number of objects in the scene. We report some examples of speedups.
U.S. EPA Brewer spectrophotometer network and the USDA UVB monitoring and research program: data comparison from co-located instruments

Several ground based ultraviolet (UV) monitoring networks exist in the United States, each of which is unique in the instrumentation employed for measurements. Two of these UV networks are the US EPA’s Brewer Spectrophotometer network and the USDA’s UVB Monitoring network, with a combined instrument total of 52 sites throughout the mainland USA, US territories and some overseas locations. The Brewer records full sky spectra from 287-363nm with 0.5nm resolution whereas the USDA instrument is a broadband device that measures broadband erythemally weighted UV data over a number of bands in the UV. To date, limited comparisons of data collected from these networks have been analyzed for comparative and quality assurance (QA) purposes. The data used in this paper is taken from sites where instruments from each program are co-located, namely, BigBend National Park, Texas and Everglades National Park, Florida. In order to reduce the contribution of errors in the Brewer-based instruments, the raw data has been corrected for stray light rejection, the angular response of the full sky diffuser, the temperature dependence of the instruments and the temporal variation. This reduces the estimated errors of the absolute irradiance values of each Brewer spectral measurement to approximately ±5%. The estimated uncertainty of the USDA instruments is also ±5%. Uncertainty is comprised of (1) standard lamp measurement errors, (2) spectral response determination and (3) the angular response of the diffuser. In this paper, we perform spectrally resolved comparisons between the Brewer UV irradiance measurements and the data collected by the broadband erythemal UV meters at co-located sites between 1997 through to 2002.
Consumer Acceptance of Pawpaw (Asimina Triloba) Fruit Puree as a Fat‐Reducing Agent in Muffins, Compared to Muffins Made with Applesauce and Fat

This study determined the consumer acceptance of pawpaw pulp as a fat-reducing agent in muffins as compared to muffins made with fat (regular) and muffins made with applesauce. No significant differences were noted between the applesauce and pawpaw muffins. Overall, the analysis of variance indicated the muffins made with pawpaw puree were equally acceptable to the other muffins for all characteristics, with the exception of appearance (color), in which regular muffins were preferred over the pawpaw variation. The muffins made with applesauce were equally acceptable to the other muffins, with the exception of texture and overall acceptability, in which the regular muffins were preferred. Given efforts to domesticate the pawpaw, family and consumer sciences professionals should be aware of this fruit and its potential use as a fatreducing agent.
Grand opportunities in physiology to address the grand challenges facing the planet.

For people, plants can seem like aliens. Movements are typically slow, and many consider plants “slow and low life [sLow life]” (Hangarter, 2009). Their appearance and behavior are so different from ourselves that we are in awe when we learn that many of the central functions of plants and humans are encoded by highly conserved genes. For example at the core of metabolism, hexokinase, the enzyme that phosphorylates incoming glucose, and many of the proteins that transport glucose look strikingly similar. This similarity goes yet deeper, as hexokinase has two distinct functions both as an enzyme and as a sensor (“sensyme”), a duality that appears to be conserved from plants to fungi to animals (Frommer et al., 2003). In a second example, the identification of the first higher plant ammonium transporter allowed a function to be assigned for the first time to an important human locus – the Rhesus factor (Ninnemann et al., 1994; Marini et al., 1997). One of the most recent and striking examples of functional similarities was the finding that both plants and animals use carbonic anhydrase to sense carbon dioxide – in humans permitting champagne bubbles to be tasted, and in plants crucial for control over the gas exchange with the atmosphere (Frommer, 2010). McGary et al. (2010) found that plants and people share at least 48 functional modules; sets of genes that act in common to produce a phenotype. Many of these are disease-related. “There was a lot of screaming in the halls for that one [sic what was conceived as unexpected similarity]” as Edward Marcotte, a cancer researcher at the University of Texas, stated in the New York Times (Zimmer, 2010). This “deep homology” in functional networks, identified through the use of large datasets from the TAIR Arabidopsis database (www.arabidopsis.org/) argues strongly that research in plants can not only unravel the secrets of plants, but can guide research in metazoan organisms. It is apparently a consequence of evolution, where much remains to be learned about the first ancestors of multicellular green organisms and the mechanisms that had to evolve to allow for efficient photosynthesis, gas exchange, efficient mining of mineral nutrients and multicellularity.
In situ, real-time diagnostics of OMVPE using IR-diode laser spectroscopy☆

Absorption IR-diode laser spectroscopy was used to monitor the vibrational frequencies of gaseous species within an OMVPE reactor. The IR-diode laser system, when tuned to a metalalkyl line, served as an on-line monitor of flow dynamics in the OMVPE reactor. The effects of gas velocity, diffusion into or out of dead spaces, pressure variations, etc. were readily identified and measured. Absorption lines associated with the metastable methyl radical were observed during the decomposition of trimethylindium and trimethylgallium. Results indicate that the decomposition of the metal alkyls proceeds via the removal of methyl radicals, and that there is a maximum methyl production at a temperature which increases with group III metal-carbon bond strength, i.e. In-C, Ga-C, Al-C. It is also observed that the CH3 radicals play a significant role in the decomposition of arsine and the formation of GaAs in OMVPE.
On computing the spectral radius of the Hankel plus Toeplitz operator

The square root of the spectral radius of the Hankel plus Toeplitz operator has been shown to be the achievable performance of the mixed-sensitivity H/sup infinity / design. The computation of the spectral radius is the bottleneck in the synthesis of the H/sup infinity / controller. In this paper, the spectral properties of the Hankel plus Toeplitz operator are investigated. A finite procedure for computing the spectral radius of the Hankel plus Toeplitz operator is proposed. >
Clearing the Way for Unpaused Polymerases

Heat shock loci in the polytene chromosomes of the fruit fly Drosophila undergo a characteristic change in appearance that coincides with the onset of gene expression. Petesch and Lis (2008) now show that nucleosomes are lost across the entire Hsp70 locus in an initial wave that precedes transcription by RNA polymerase II.
33 EXCHANGE TRANSFUSION AND ROSETTE-FORMING CELLS

Cellular immunity was studied by the spontaneous rosette forming lymphocyte technique in the peripheral blood of fourteen jaundiced newborns, who were exchange transfused. Following exchange transfusion a gradual increase of both per cent and absolute values of rosette-forming cells was observed. On the 7th post exchange transfusion day per cent rosettes had almost doubled (t=11.2 , P< 0.001) whereas absolute numbers had increased by more than two fold (t=6.37 , P<0.001). These results suggest that the therapeutic benefit of exchange transfusion in severely ill newborns may be due appart from other factors to its stimulating effect on cellular immunity.
Choline administration to the rat increases urinary catecholamines

Previous studies have shown that choline administration accelerates the synthesis of acetylcholine (ACh) in rats and raises ACh levels in brain, adrenal medulla, and other tissues receiving a cholinergic innervation. After 24 hours, this precursor-induced elevation in ACh levels causes tyrosine hydroxylase activity to increase, unless the adrenals have been previously denervated. We now report that oral choline administration also increases urinary epinephrine levels, probably by enhancing the release of the catecholamine from the adrenal gland. For four consecutive 4-day periods, male Sprague-Dawley rats received (1) no treatment, (2) water, (3) choline (20 mmoles/kg), and (4) water, and excreted 157, 200, 646, and 267 ng of epinephrine per 24-hour period, respectively. Urinary norepinephrine levels also increased on days that the animals received choline. Choline failed to increase urinary epinephrine levels among rats previously subjected to bilateral adrenal denervation; in contrast, nicotine, a direct-acting cholinergic agonist, continued to elicit this increase. Thus, choline administration apparently potentiates the increase in urinary epinephrine produced by treatments that accelerate the flow of impulses along the splanchnic nerves. These data provide additional support for the hypothesis that choline administration, by increasing presynaptic ACh levels, enhances cholinergic transmission at preganglionic synapses of the sympathetic nervous system.
Oil production from catfish viscera

Oil was extracted from catfish viscera and purified (degummed, neutralized, bleached, and deodorized). The yield of catfish oil after purification was 65.7%. The major yield loss took place during the degumming process. The FA found in crude catfish visceral oil were 14∶0, 16∶0, 16∶1, 18∶0, 18∶1, 18∶2, 18∶3, 20∶0, 20∶1, 20∶2, 20∶3, 20∶4, and 22∶6, the predominant FA being 18∶1, 16∶0, 18∶2, and 18∶0. The total unsaturated FA in the purified catfish oil amounted to 67.7%. The combined n−3 FA content of the purified catfish oil was 4.6 mg/g of oil. The purified catfish oil contained 1.21 mg/g DHA. FFA, water activity, and some mineral contents decreased during purification. Bleaching removed pigments, thus resulting in oil with greater lightness and less yellowness.
A Higher Order Paraxial Ray Theory

Abstract A method based on the paraxial ray equation is described for obtaining solutions to the equations of space-charge limited (low for electrostatic systems. According to usual practice any two parameters—voltage, curvature, and infinitesimal beam thickness—are prescribed along a central trajectory, and then the remaining parameters are found from the paraxial ray equation. The flow about the central trajectory is then found by solving for a curvilinear coordinate system satisfying the boundary conditions and with coordinate axes coinciding with the emitter and central trajectory. This is done by solving a set of ordinary differential equations derived from the paraxial ray equation. These are then combined according to a power series expansion to yield the complete flow solution anywhere along the central trajectory. The focusing electrodes are found by the method of analytic continuation. An ion propulsion gun designed by this method is described.
Brief Report: Do Delinquency and Community Violence Exposure Explain Internalizing Problems in Early Adolescent Gang Members?

Adolescent gang members are at higher risk for internalizing problems as well as exposure to community violence and delinquency. This study examined whether gang membership in early adolescence is associated with internalizing problems (depression, anxiety, and suicidal behavior) and whether these associations are mediated by delinquency and witnessing community violence. In a sample of 589 ethnically diverse early adolescents, gang membership was related to suicidal behavior but not depression or anxiety. Both delinquency and witnessing community violence mediated this association. Professionals working with gang members should assess these youth for suicidal behavior and provide interventions as needed.
Bidirectional Calibration Results for 11 Spectralon and 16 BaSO4 Reference Reflectance Panels

Abstract Eleven Spectralon 1 (a sintered polytetrafluoroethylene-based material) and 16 BaSO4 reference reflectance panels were calibrated using a field calibration technique. The Spectralon panels differed both in their directional/hemispherical and directional/directional reflectance. However, the differences were sufficiently small that “general” calibration equations were developed. For panels constructed of the same material and with the same methods as those used in these experiments, the directional/directional reflectance may be within ± 0.020 at 10°, ± 0.015 at 45°, and ± 0.041 at 80° of that predicted by the “general” equations. For field measurements, these values are considerably better than those that would be obtained using a value of the directional/hemispherical reflectance. The directional/directional reflectance of the 16 BaSO4 panels varied considerably among panels, so much so that it was not feasible to develop “general” calibration equations. Apparently, the nonlambertian properties of BaSO4 panels are dependent upon the method of applying the barium sulfate coating.
Postulates for an Abstract Arithmetic

I here give a precise definition of an abstract arithmetic, that is, one whose elements are marks in the technical sense, and state a few of its simpler properties. The principal advance over the work summarized in "General Arithmetic" lies in the fact that I no longer assume that "multiplication" is commutative.
Evaluation of liposome-encapsulated clindamycin inStaphylococcus aureaus endophthalmitis

We investigated the effects of liposime-encapsulated clindamycin inStaphylococcus aureaus endophthalmitis induced in rabbits. Clindamycin was encapsulated into liposomes, and suspended in two concentrations: 1 mg/0.1 ml and 2 mg/0.1 ml of clindamycin phosphate. Seven eyes received an intravitreal injectin (0.1 ml volume) containing 1 mg of liposome-encapsulated clindamycin and seven eyes received 2 mg. Three control rabbits (six eyes) received drug-free liposomes (three eyes) and no treatment (three eyes). All but one eye treated with clindamycin recovered. All control eyes, inclduing those treated with empty lipsomes, were lost to infection.
Paleoprimatological research over the last 50 years: Foci and trends

Since 1930 the approach to fossil primates has undergone a twofold revolution, in more advanced taxonomic thinking, and in the growth of studies relating living primates to the interpretation of past forms. Great strides have also been made in discovering primate fossils–in 1930 there were some 58 genera of extinct primates known, and since then more than 65 new genera have been named. A major aspect of paleoprimatological research today is multidisciplinary field projects, which have accounted for a fuller understanding of dating and context. The application of functional morphology to aspects of primate evolution has allowed better understanding of primate locomotion, diet, and behavior.
The relation of phosphate metabolism to oxidative assimilation of acetate by Euglena gracilis var. bacillaris. ffects of 2,4-dinitrophenol.

SYNOPSIS. Oxidative assimilation of acetate by Euglena gracilis var. bacillaris occurs without appreciable net transfer of inorganic phosphate between cells and medium. Low concentrations of the “uncoupling agent” 2,4-dinitrophenol (2–5 μM, pH 5) stimulate acetate oxidation and inhibit acetate assimilation. These dinitrophenol concentrations have no measurable effect on edogenous respiration. Higher concentrations inhibit respiration on acetate, and still higher concentrations inhibit endogenous respiration. Dinitrophenol concentrations which stimulate acetate oxidation produce no measurable change in the total ATP content of the euglena cells. Higher concentrations (50–100 μM) cause progressive decrease in the ATP content. A hypothetical mechanism is proposed which accounts for the normal, constant oxidation-assimilation ratio for acetate as the result of coupling of oxidative ATP synthesis with assimilatory ATP consumption. The data are consistent with this mechanism if it is additionally assumed that oxidation and assimilation of acetate occur in an intracellular “compartment” separated from other sources and sinks of ATP.
The Efficacy of Incentives to Motivate Continued Fitness-Center Attendance in College First-Year Students: A Randomized Controlled Trial

Abstract Objective: To determine whether fitness-center attendance established with the provision of weekly monetary incentives persisted after the discontinuation, or decreased frequency, of incentives. Participants: One hundred seventeen first-year college students participated during the 2011–2012 academic year. Methods: A randomized controlled trial with control, discontinued-incentive, and continued-incentive conditions was conducted. During fall semester, students in incentive conditions received weekly monetary payments for meeting fitness-center attendance goals. During spring semester, discontinued-incentive condition participants no longer received incentives, whereas continued-incentive condition participants received payments on a variable-interval schedule. ID-card attendance records tracked fitness-center attendance. Results: Goal completion decreased from 63% in the incentive groups during the fall semester to 3% in the discontinued-incentive condition, and 39% in the continued-incentive co...
Energy harvesting from flutter instabilities of heavy flags in water through ionic polymer metal composites

In this paper, we analyze underwater energy harvesting from the flutter instability of a heavy flag hosting an ionic polymer metal composite (IPMC). The heavy flag comprises a highly compliant membrane with periodic metal reinforcements to maximize the weight and minimize the bending stiffness, thus promoting flutter at moderately low flow speed. An IPMC strip is mechanically attached to the host flag and connected to an external load. The entire structure is immersed in a background flow whose intensity is parametrically varied to explore the onset of flutter instability along with the relation between the vibration frequency and the mean flow speed. Manageable theoretical models for fluid-structure interaction and IPMC response are presented to inform the harvester design and interpret experimental data. Further, optimal parameters for energy scavenging maximization, including resistive load and flow conditions, are identified.
Abnormal Hemodynamic Function After Disc Mitral Valve Replacement

Although disc valves have been used extensively for mitral valve replacement, few long-term hemodynamic studies are available. Twenty-five patients received a Kay-Shiley valve, and hemodynamic studies were obtained in 17 patients at an average interval of 15 months after operation. Left ventricular cineangiograms revealed mitral insufficiency in 8 of 15 patients. In three patients a poorly contracting myocardium was associated with elevated left ventricular end-diastolic pressures, suggesting the possibility of acquired endocardial fibroelastosis. The embolic rate was 38%. Two valves became severely stenosed, and two had severe paravalvular leaks which required replacement. Although most patients were improved symptomatically and hemodynamic studies revealed improvement, all had abnormal valve function, particularly during exercise.
Neocortical somatostatin neurons reversibly silence excitatory transmission via GABAb receptors.

Summary Background Understanding the dynamic range for excitatory transmission is a critical component of building a functional circuit diagram for the mammalian brain. Excitatory synaptic transmission is typically studied under optimized conditions, when background activity in the network is low. The range of synaptic function in the presence of inhibitory and excitatory activity within the neocortical circuit is unknown. Results Paired-cell recordings from pyramidal neurons in acute brain slices of mouse somatosensory cortex show that excitatory synaptic transmission is markedly suppressed during spontaneous network activity: EPSP amplitudes are 2-fold smaller and failure rates are greater than 50%. This suppression is mediated by tonic activation of presynaptic GABAb receptors gated by the spontaneous activity of somatostatin-expressing (Sst) interneurons. Optogenetic suppression of Sst neuron firing was sufficient to enhance EPSP amplitude and reduce failure rates, effects that were fully reversible and occluded by GABAb antagonists. Conclusions These data indicate that Sst interneurons can rapidly and reversibly silence excitatory synaptic connections through the regulation of presynaptic release. This is an unanticipated role for Sst interneurons, which have been assigned a role only in fast GABAa-mediated inhibition. Because Sst interneuron activity has been shown to be regulated by sensory and motor input, these results suggest a mechanism by which functional connectivity and synaptic plasticity could be gated in a state-dependent manner.
Decomposition of turtlegrass (Thalassia testudinum Konig) in flowing sea-water tanks and litterbags: Compositional changes and comparison with natural particulate matter

Thalassia testudinum Konig litter was incubated up to 3 yr in flowing sea-water tanks and litterbags in the field. Weight loss of litter was evident within 1 wk and 50% loss of ash free dry weight took < 35 days. Carbon and nitrogen were lost from litter, but the C: N ratio (by weight) changed only slightly over the first 180 days of incubation. Protein, carbohydrate, and lipid content of litter decreased with time. Number of bacteria on litter increased from ˜ 9 to 37-60 × 109 cells • g dry wt-1. Lipid synthesis activity suggested a succession in the litter microbial community. Thalassia detritus from long-term tank incubations (2 to 3 yr) exhibited similarities in biochemical composition with particulate matter in natural water.
Precambrian Geomagnetic Reversal Stratigraphy

REVERSALS of polarity are encountered in Precambrian rocks. It is therefore important to consider whether geomagnetic field reversals can be a viable stratigraphic tool in the Precambrian.
Allelopathic effects of giant foxtail on germination and radicle elongation of loblolly pine seed

Water extracts of giant foxtail grass inhibited germination and radicle elongation of loblolly pine seed in a laboratory test. Most of the toxic effects came from extracts of dried foxtail tops, with lesser amounts from fresh tops and roots. Soil texture affected the phytotoxicity of the extracts. Eight chemical compounds known to be phytotoxins inSetaria were identified in extracts of foxtail leaves but could not be found in soil samples under the leaves.
A Constitutively Active Gα Subunit Provides Insights into the Mechanism of G Protein Activation

The activation of Gα subunits of heterotrimeric G proteins by G protein-coupled receptors (GPCRs) is a critical event underlying a variety of biological responses. Understanding how G proteins are activated will require structural and biochemical analyses of GPCRs complexed to their G protein partners, together with structure-function studies of Gα mutants that shed light on the different steps in the activation pathway. Previously, we reported that the substitution of a glycine for a proline at position 56 within the linker region connecting the helical and GTP-binding domains of a Gα chimera, designated αT*, yields a more readily exchangeable state for guanine nucleotides. Here we show that GDP-GTP exchange on αT*(G56P), in the presence of the light-activated GPCR, rhodopsin (R*), is less sensitive to the β1γ1 subunit complex than to wild-type αT*. We determined the X-ray crystal structure for the αT*(G56P) mutant and found that the G56P substitution leads to concerted changes that are transmitted to the conformationally sensitive switch regions, the α4-β6 loop, and the β6 strand. The α4-β6 loop has been proposed to be a GPCR contact site that signals to the TCAT motif and weakens the binding of the guanine ring of GDP, whereas the switch regions are the contact sites for the β1γ1 complex. Collectively, these biochemical and structural data lead us to suggest that αT*(G56P) may be adopting a conformation that is normally induced within Gα subunits by the combined actions of a GPCR and a Gβγ subunit complex during the G protein activation event.
Regularities in the bond dissociation enthalpies of molecules of types AB and BAB: Energetics of 10‐ and 16‐valence electron ions of groups 13, 15, and 16

For the quantitative and qualitative understanding of molecular energetics, contemporary calorimetric and mass spectrometric measurement techniques and correspondingly high-level quantum chemical calculational methodologies increasingly work in concert. For example, letting A and B be group 14 and 16 elements, respectively, for their 10-valence electron AB and 16-valence electron AB2 gas-phase diatomic and triatomic species, the bond enthalpy ratio 〈D(AB2)〉/D(AB) has been shown to remarkably constant, namely, 0.77 ± 0.02. In the current study we discuss the corresponding bond enthalpy ratio for the valence isoelectronic cations and anions, e.g., for the carcinogen [NO]+, explosive precursor [NO2]+, and discrete (monomeric, i.e., nonsalt containing) anions [BO2]− and [AlO2]−. From a combination of results taken from archival literature measurements and new quantum chemical calculations reported in this article, again roughly constant ratios are found. Numerically, these ratios are 0.66 ± 0.03 and 0.86 ± 0.02 for cations and anions, respectively. That the ratios increase in the order cation < neutral < anion is also explained in our study. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Solution to sign problems in half-filled spin-polarized electronic systems

We solve the sign problem in a particle-hole symmetric spin-polarized fermion model on bipartite lattices using the idea of fermion bags. The solution can be extended to a class of models at half filling but without particle-hole symmetry. Attractive Hubbard models with an odd number of fermion species can also be solved. Our solutions should allow us to study quantum phase transitions that have remained unexplored so far due to sign problems.