cssi/SciSciGPT-SciSciNet huggingface dataset:
Entrainment of neocortical neurons and gamma oscillations by the hippocampal theta rhythm

Although it has been tacitly assumed that the hippocampus exerts an influence on neocortical networks, the mechanisms of this process are not well understood. We examined whether and how hippocampal theta oscillations affect neocortical assembly patterns by recording populations of single cells and transient gamma oscillations in multiple cortical regions, including the somatosensory area and prefrontal cortex in behaving rats and mice. Laminar analysis of neocortical gamma bursts revealed multiple gamma oscillators of varying frequency and location, which were spatially confined and synchronized local groups of neurons. A significant fraction of putative pyramidal cells and interneurons as well as localized gamma oscillations in all recorded neocortical areas were phase biased by the hippocampal theta rhythm. We hypothesize that temporal coordination of neocortical gamma oscillators by hippocampal theta is a mechanism by which information contained in spatially widespread neocortical assemblies can be synchronously transferred to the associative networks of the hippocampus.
Evidence that NPY Y1 receptors are involved in stimulation of feeding by orexins (hypocretins) in sated rats.

Abstract Neuropeptide Y (NPY) produced in the arcuate nucleus (ARC) of the hypothalamus stimulates feeding both directly by activating NPY receptors and indirectly through release of the orexigenic peptides, galanin and β-endorphin (β-END), in the paraventricular nucleus (PVN) and surrounding neural sites. Orexin A and orexin B, produced outside the ARC in the lateral hypothalamic area (LH), have recently been shown to stimulate feeding. In the present studies we tested the hypothesis that NPYergic signaling may mediate feeding stimulated by orexins. In adult male rats injected intracerebroventricularly (icv) with orexin A (3, 10, 15 nmol) or orexin B (3, 10, 30 nmol) feeding was stimulated in a dose-dependent manner; maximal feeding was seen after 15 nmol orexin A and 30 nmol orexin B. To determine whether NPY may mediate this orexin stimulated feeding, we used 1229U91, a selective NPY Y1 receptor antagonist (NPY-A). Whereas NPY-A on its own was ineffective, it suppressed NPY-induced feeding. Furthermore, NPY-A completely blocked the feeding evoked by either orexin A (15 nmol) or orexin B (30 nmol). These results show that orexin A and B stimulate feeding and further suggest that these excitatory effects may be mediated by NPYergic signaling through Y1 receptors. These findings are in accord with the view that the orexin–NPY pathway may comprise a functional link upstream from NPY within the hypothalamic appetite regulating network.
1,4-dibenzylpiperazines possess anticocaine activity.

N,N-Dibenzylpiperazines have high affinity for sigma receptors, and we aimed to increase their anticocaine activity by introducing substituents known to enhance such activity in other sigma ligands. Ligands with high affinity for sigma-1 receptors resulted, but their activity in attenuating cocaine-induced convulsions did not correlate with sigma-1 binding affinity, and may be more closely related to their sigma-2 binding affinities.
Strain-controlled torsional test method for screening the performance of composite materials at cryogenic temperatures

A system has been developed for rapid measurement of the torsional properties of organic-matrix composite materials at temperatures from 4 to 295 K. It offers ease of construction, simplicity of specimen design, small specimen size, rapid specimen turnaround, and low consumption of cryogens. In addition to providing quantitative data on the modulus of rupture and of rigidity, the strain-control feature facilitates analysis of the stress-displacement curve in the region where damage is occurring, providing useful information on the influence of various parameters on the failure mode. The system was optimized for rapid screening of the influence of component variables on the performance of electrical insulators required to function in the cryogenic irradiation environment of superconducting magnets in magnetic fusion energy systems. However, it is also useful in studying the influence of cryogenic environment on unreinforced polymers and on metals and alloys.
On some aspects of the wheel/rail interaction

Abstract Problems in tribology and contact mechanics are becoming increasingly amenable to solution through models and simulation. But in application to the wheel/rail contact, there remain a number of very important features for which either gross simplifications or a lack of understanding or ability severely limits the success of those efforts. Examples include models of friction and material response (including damage functions). This paper examines a rather eclectic mix of wheel/rail factors with the goal of encouraging researchers to begin tackling and eradicating some of the bigger problem areas that remain in wheel–rail interaction modeling and to consider more rigorous implementation of real world conditions in simulations.
China's Development Could Lead to Bottom Water Formation in the Japan/East Sea

Abstract Using hydrographic data and box models, it is shown that the presently discussed diversion of rivers such as the Yellow or the Yangtze for agricultural use is likely to cause the renewal of Bottom Water formation in the Japan/East Sea. Such formation was common (near the Siberian coast) in the 1930s, 1940s, and 1950s, but subsided since that time due to a warming trend (accompanied by a decreased salinity due to the melting of ice). Since a diversion of freshwater is analogous to evaporation, a (diversion induced) increase of salinity is expected and the increase is large enough to allow Bottom Water formation even at the present–day cooling rates. Even a modest diversion of "merely" 3000 m3 s–1 (which is 10% of the total freshwater flux) will probably cause Bottom Water formation at a rate of roughly 750 000 m3 s–1. This is the first study that predicts anthropogenic reversal of an existing vertical structure in a semienclosed sea.
Interspecies allometric analysis of the comparative pharmacokinetics of 44 drugs across veterinary and laboratory animal species

Allometric scaling is widely used for the determination of first dosage regimen and the interpolation or extrapolation of pharmacokinetic parameters across many animal species during drug development. In this article, 85 drugs used in veterinary medicine obtained from the Food Animal Residue Avoidance Databank database were selected for allometric scaling analysis. Outlier species were identified by statistical methods. The results showed that 77% and 88% of drugs displayed significant correlations between total systemic clearance (CL) and volume of distribution at steady status (Vss) vs. body weight (P < 0.05) on a log-log scale, respectively. The distribution of the allometric exponent b for CL and Vss displays approximate normal distribution, with means (0.87 and 0.99) and standard deviations (0.143 and 0.157) for CL and Vss, respectively. Twelve drugs were identified to have at least one outlier species for CL and ten drugs for Vss. The human CL and Vss were predicted for selected drugs by the obtained allometric equations. The predicted CL and Vss were within a threefold error compared to observed values, except the predicted CL values for antipyrine, warfarin and diazepam. The results can be used to estimate cross-species pharmacokinetic profiles for predicting drug dosages in veterinary species, and to identify those species for which interpolation or extrapolation of pharmacokinetics properties may be problematic.
Oxene transfer, electron abstraction, and cooxidation in the epoxidation of stilbene and 7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene by hemoglobin.

Hemoglobin plus H2O2 oxidizes trans-stilbene to trans-stilbene oxide, cis-stilbene to cis- and trans-stilbene oxide, and trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene to anti-trans-7,8,9,10-tetrahydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene. Oxidation of cis- and trans-stilbene to the corresponding cis- and trans-epoxides proceeds exclusively with incorporation of oxygen from the peroxide. Oxidation of cis-stilbene to the trans-epoxide, however, proceeds without detectable incorporation of oxygen from the peroxide and partial incorporation of oxygen from O2. The epoxidations in which stereochemistry is conserved thus appear to involve ferryl oxygen transfer, whereas the epoxidations in which stereochemistry is inverted are proposed to involve protein-mediated cooxidation [Ortiz de Montellano, P.R., & Catalano, C.E. (1985) J. Biol. Chem. 260, 9265-9271] and possibly electron abstraction-water addition. The epoxidation of trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene incorporates oxygen from H2O2 and H2O but not O2. The oxidation of this substrate is thus consistent with ferryl oxygen transfer and electron abstraction but not protein-mediated cooxidation.
Simple model and wave function for atoms in intense magnetic fields

The structure of heavy atoms in strong magnetic fields of the order of ${10}^{12}$ G, such as are generally presumed to be present on pulsars, has been previously described in terms of a magnetic Thomas-Fermi (TF) model, suitably adapted from the normal TF model. We present here a model which is analogous to the well-known screening-theory approach for ordinary, "laboratory" atoms---the electrons occupy various orbits with a transverse dimension characterized by the radius of magnetic cyclotron orbits and an over-all dimension characterized by Bohr orbits. Not only does this model give results similar to, though quantitatively more reliable than, the magnetic TF model, but it provides more insight into the structure of atoms in strong magnetic fields. For instance, the number of electrons in the $n\mathrm{th}$ shell is seen to be proportional to ${n}^{4}$ instead of the usual $2{n}^{2}$ in the laboratory situation. This accounts for the tighter binding of such atoms, a result already derived in the magnetic TF model, but also goes further in suggesting a new kind of shell structure and a new Periodic Table for atoms in strong magnetic fields. Quantum mechanically, our model is based on energy minimization with a simple analytical wave function and this represents the first time a simple wave function has been suggested for heavy atoms in strong magnetic fields. The wave function consists of an antisymmetrized product of single-particle orbitals, each of which is a product of an ordinary hydrogenic radial function and a magnetic Landau orbital so that both the spherical Coulombic and cylindrical magnetic symmetry of the problem are taken into account. However, in analogy with Bohr theory, we motivate and discuss many of the results without explicit use of this wave function. An approximate electron density function is trivially established which is itself physically more reasonable than the corresponding magnetic TF function. Further, our model is valid over a broader range of magnetic-field values and its variational-bound character allows for both successive improvements in its predictions and for a knowledge of the sign of the error in the energy estimate. Useful scaling laws are presented so that, starting from the knowledge of the ground-state energy for some $Z$ and $B$, the energy for other combinations of $Z$ and $B$ can be estimated. A second major result of this paper is that the single-particle wave function that arises during the course of the development of the many-electron wave function is of interest in itself, combining as it does aspects of both spherical and cylindrical symmetry. This simple wave function seems to describe well the ground state of the hydrogen atom at all values of the magnetic field.
On the writing of ‘the world city hypothesis’

(1996). On the writing of ‘the world city hypothesis’. Scottish Geographical Magazine: Vol. 112, No. 2, pp. 127-128.
Predictors of Paternal Involvement in Childcare in Dual-Earner Families with Young Children

Dual-earner parents (N = 119) of preschool children enrolled in licensed childcare centers completed anonymous questionnaires that examined work and family variables as related to paternal involvement in three areas: engagement (i.e., one-on-one interaction with the child), responsibility (i.e., taking care of the child’s needs), and accessibility (i.e., being available to the child without directly interacting). Paternal responsibility was predicted by beliefs about fathering and structural variables (e.g., hours fathers and mothers worked). The percentage of time fathers spent as their child’s primary caregiver was predicted by structural variables (e.g., mothers’ work hours) and belief variables (e.g., men’s beliefs about fathering and fathers’ parenting self-efficacy). Paternal engagement and accessibility were not significantly predicted by any of the constructs examined.
Optimal compliance criterion for axisymmetric solid plates

Abstract The problem of minimum compliance of solid plates is formulated in statical terms. It is shown that a previously derived optimality condition is merely a stationary condition. Additional necessary conditions for optimality that distinguish local minima from local maxima are derived from the second variation on the compliance. Although designs which are local minima may exist, it is shown that an absolute minimum does not. An example is presented for which both a local minimum and a local maximum are obtained.
Adolescent and Young Adult Mothers' Relationship Quality During the Transition to Parenthood: Associations with Father Involvement in Fragile Families

Data from the Fragile Families and Child-Well-being Study were used to examine predictors of involvement among fathers of young children (N=2,215) born to adolescent and young adult mothers (ages 14–25; N=2,850). Participants were interviewed immediately following their baby's birth and at 3-years postpartum regarding co-parental relationship quality, fathers’ caretaking behavior (“father involvement”), and fathers’ provision of material support for the child (“in-kind” support). Early postnatal and 3-year postpartum parental relationship quality and father-child cohabitation predicted 3-year father involvement while early father involvement did not. The race of fathers, specifically African American, was associated with lower levels of father involvement. For in-kind support, 3-year father-child cohabitation and 3-year relationship quality were both positively associated with provision of in-kind support. Father's income was not a significant predictor but mother's involvement with a new partner at the 3-year follow-up was marginally significant. Lastly, the race of fathers, specifically African American and Latino, was associated with provision of less in-kind support.
OA06.04. Dose-response of spinal manipulation for chronic low back pain: pain and disability outcomes from a randomized controlled trial

Methods We randomized 400 patients with cLBP to receive one of four dose levels of care: 0, 6, 12, or 18 sessions of lumbar spinal manipulation from a chiropractor. All participants were scheduled for three visits per week for six weeks at one of eight clinics. Care was rendered at each visit, either the index intervention or light massage control. The primary outcomes were low back pain intensity and functional disability at 12 and 24 weeks (100-point scales). Secondary outcomes included days with pain and functional disability, pain unpleasantness, global perceived improvement, and general health status. Outcomes were assessed at baseline and at 6, 12, 18, 24, 39, and 52 weeks. Linear dose effects and group comparisons (efficacy) were evaluated using covariateadjusted simultaneous regression for continuous data (primary analysis). Binomial regression was performed in a responder analysis of 50% improvement (secondary analysis).
Reverse dosimetry: interpreting trihalomethanes biomonitoring data using physiologically based pharmacokinetic modeling

Biomonitoring data provide evidence of exposure of environmental chemicals but are not, by themselves, direct measures of exposure. To use biomonitoring data in understanding exposure, physiologically based pharmacokinetic (PBPK) modeling can be used in a reverse dosimetry approach to assess a distribution of exposures possibly associated with specific blood or urine levels of compounds. Reverse dosimetry integrates PBPK modeling with exposure pattern characterization, Monte Carlo analysis, and statistical tools to estimate a distribution of exposures that are consistent with biomonitoring data in a population. The present study used an existing PBPK model for chloroform as a generic framework to develop PBPK models for other trihalomethanes (THMs). Using Monte Carlo sampling techniques, probabilistic information about pharmacokinetics and exposure patterns was included to estimate distributions of THMs concentrations in blood in relation to various exposure patterns in a diverse population. In addition, the possibility of inhibition of hepatic metabolism among THMs was evaluated under the scenarios of household exposure. These studies demonstrated how PBPK modeling can be used as a tool to estimate a population distribution of exposures that could have resulted in particular biomonitoring results. When toxicity level is known, this tool can also be used to estimate proportion of population above levels associated with health risk.
A response to Johnson and Hogan

I will try to keep my response to Johnson and Hogan (1980) as brief as possible: The role-playing issue. Although test-taking (and personality in general) undoubtedly involves a certain amount of role-playing or selfpresentation, such role-playing can take two fundamentally different forms. On the one hand, an individual may attempt to present an image that is consistent over a variety of different situations or occasions. In this case the individual’s role or “face” (Goffman, 1967), including its particular enactment on a given personality test, carries many of the same implications that we associate with the concept of personality (e.g., consistency, individual differences). On the other hand, role playing may also refer to an individual’s attempt to alter his or her performance to fit the particular situation or audience at hand. In this second case, which is clearly the form of self-presentation or impression management that we were concerned with in Experiment 1 of the Meehan, Woll, and Abbott (1979) study, the individual’s role would appear to be inconsistent with any meaningful conception of personality and with any attempt to assess personality. Thus, our conclusion from Experiment 1 still stands: if subjects can manage their impressions on the SEA as readily and with as high a degree of consensus as our results indicate, it seems rather misleading to construe that scale as a measure of attitudes (or a disposition to adopt a set of attitudes-f. Hogan, 1973) or of personality. The social desirability issue. Johnson and Hogan argue that scores on the SEA cannot be accounted for by the social desirability of the test items because “these ratings” (presumably referring to the SDSV ratings) are context(or audience-) dependent, and because there are individual differences in such ratings. The point at issue, however, is not whether each subject’s score can be completely accounted for by his or her social
Nodeless d-wave pairing in a two-layer Hubbard model.

Pairing correlations in a two-layer Hubbard model are studied using (1) an Eliashberg-like approximation for the exchange of spin fluctuations and (2) quantum Monte Carlo simulations. A possible pair structure in which the gap has one sign on the bonding and the opposite sign on the antibonding Fermi surface is found. Some implications of this for the transport properties of the cuprate superconductors are discussed.
Evaluation of the fit and strength of an all-ceramic fixed partial denture.

Summary A laboratory investigation of the fit and strength of three-unit all-ceramic FPDs was performed with a metal-ceramic FPD control. The conclusions were: 1. No difference was found between the marginal seal of the metal-ceramic and all-ceramic FPDs. 2. The all-ceramic FPDs had a more uniform cement space and their occlusal seat was significantly (99.9%) better than the metal-ceramic restorations. 3. The metal-ceramic FPDs were significantly stronger than the all-ceramic FPDs. 4. Load calculations suggest that short-span allceramic FPDs may be strong enough to resist normal masticatory forces for selected patients. However, generalized usage will probably result in an unacceptable failure rate.
Structural evaluations and dynamic testing of solar electric propulsion components.

Results of an experimental and analytical study of selected Solar Electric Propulsion (SEP) thrust subsystem components are presented. A mass and center-of-mass mockup of an experimental power conditioning (PC) panel was used for the PC structure evaluation. Test environment was based on that specified for prooftesting the Viking spacecraft electronics. Modal frequencies were surveyed over the range of 0-2000 Hz using both conventional test equipment and the holographic interferometry technique. Results of the forced vibration tests point to the need for some additional stiffening to make the structure qualifiable.
Correlations among human blood levels of specific PCB congeners and implications for epidemiologic studies

Specific congeners of PCBs may differ with respect to their human health risks. For epidemiologic studies, however, measuring levels of specific congeners—as compared with estimating the concentration of total PCBs present, may be of limited value if levels of specific congeners are highly correlated. We examined the correlations among levels of specific congeners in three groups: controls from a case-control study of breast cancer in North Carolina and two groups from Wisconsin with exposure to fish from contaminated waters. Levels of specific congeners were, in general, highly correlated (Pearson r > 0.80). However, the level of congener 180, a heptachlorobiphenyl, tended to be less correlated with levels of lower-chlorinated biphenyls. Among the implications of these findings are that measurement of a select group of congeners may yield essentially the same information as measurement of a large panel, and may be more cost efficient. Am. J. Ind. Med. 32:606–613, 1997. © 1997 Wiley-Liss, Inc.
Soil health as a predictor of lettuce productivity and quality: A case study of urban vacant lots

Urban agriculture offers a framework for local self-reliance and resilience in cities. However, there is a concern over the capacity of urban soil to provide sustainable and safe food production. We tested the effectiveness of several soil health indicators to predict food crop productivity and quality in vacant lots in a disadvantaged neighborhood in the city of Cleveland, Ohio. We defined soil health as a state of composite well being in terms of biological, chemical, and physical properties of the soil as they relate to crop productivity. Twelve city-owned vacant lots, three close to each of the four city schools, were selected for soil properties and plant growth analyses. Soil samples were analyzed for pH, moisture content (θv), soil texture, soil organic matter (SOM), active carbon (AC), ammonium (NH4-N), nitrate (NO3-N), microbial biomass N (MBN), and nematode community parameters including total (TNN), bacteria-feeding (BFN), fungal-feeding (FFN), and plant-parasitic (PPN) nematodes, number of nematode genera (NNG), and nematode food web enrichment index (EI) and structure index (SI). Lettuce was planted in the selected vacant lots and its growth was documented through measures of dry biomass, numbers of leaves/plant, and complementary subjective appearance scores related to physiological status. All measured parameters varied considerably among vacant lots except soil pH. Principal components analysis revealed that among the primary soil physical, chemical, and biological parameters, soil clay, NO3-N, MBN, SOM, AC, TNN, BFN, FFN, and PPN contributed most to the variance of the entire dataset. There were also several positive correlations among these key soil health predictor variables: AC was positively correlated with clay, SOM, MBN, TNN, BFN, FFN and PPN, and TNN was positively correlated with AC, SOM, MBN, BFN, FFN and PPN. Of the identified primary soil health indicators, only clay, SOM, and MBN positively correlated with lettuce dry biomass, which was also positively correlated with a secondary soil health indicator, the nematode food web EI. Lettuce leaf necrosis was negatively correlated with clay, AC, SOM, MBN, TNN, FFN, and PPN, and the proportion of withered leaves was negatively correlated only with SOM. It is concluded that AC, PPN, TNN, SOM, MBN, clay, and nematode food web EI can serve as important soil health indicators that have potential for predicting crop productivity and quality in urban soils. It is also concluded that lettuce can serve as an important indicator of soil health with respect to crop productivity and quality in vacant lots.
Fenton Chemistry of FeIII-Exchanged Zeolitic Minerals Treated with Antioxidants

Respirable mineral fibers, such as asbestos, are known to cause pleural mesothelioma, pulmonary fibrosis, and bronchial carcinoma, often years after exposure. Erionite and mordenite, two mineral aluminosilicates (zeolites) with different toxicities, can be used as models to help understand asbestos toxicity. Erionite is carcinogenic, while mordenite is relatively benign. No iron is typically present in erionite or mordenite, but because of their ion-exchange properties they can acquire iron after inhalation. The iron is typically in the Fe(III) form and will need to be reduced prior to any Fenton activity. Lung lining fluid contains antioxidants, such as glutathione (GSH) and ascorbic acid (AA), which can reduce Fe(III) to Fe(II). In this study, we have compared the Fenton reactivity of Fe(III)-exchanged erionite and mordenite after treatment with antioxidants. The Fenton assay involved the reaction of hydroxyl radicals with dimethyl sulfoxide. Fenton reactivity was most marked with AA followed by GSH, and hydrogen peroxide also exhibited minor reactivity. Erionite generated an order of magnitude greater hydroxyl radicals than mordenite, normalized to the surface iron content, providing support for the hypothesis that the iron coordination at the mineral surface plays a significant role in bioactivity.
Correlation and multiplet hole theory of core‐electron energy splittings in transition‐metal ions

A theory of multiplet hole splittings of core-electron binding energies in transition-metal ions is developed including correlation effects. Correlation effects are found to be important for understanding the magnitude and intensity ratios of the observed splittings. New multiplet structure is predicted for the 3s multiplets, a structure which does not exist in any rigorous one-electron theory and which has now been observed by Kowalczyk et al.
Monte Carlo Simulations of Guanidinium Acetate and Methylammonium Acetate Ion Pairs in Water

Abstract Free energy profiles of guanidinium acetate and methylammonium acetate ion pairs in water were calculated using Monte Carlo simulations. Both systems display a single shallow free energy minimum at a distance corresponding to a contact ion pair. Hydrogen bonding between the ions is an important feature in the association. The weakness of association is attributed to weaker solute–solvent interaction as the ions approach one another, as reflected in the loss of some of the water molecules hydrating the ions.
Social Security and the Public Sector: The Windfall Elimination Provision and the Government Pension Offset

The application of social security to most of the public sector has generated measures to address the resulting inequities and a campaign to repeal or modify those measures.
Benthic sediment influence on dissolved phosphorus concentrations in a headwater stream

Phosphate interacts with inorganic sediment particles through sorption reactions in streams. Collectively, this phosphorus (P) buffering mechanism can be an important determinant of soluble reactive P (SRP) concentrations. If sorption reactions control SRP concentrations in a stream, then differences in sediment characteristics may cause spatial differences in SRP concentrations. This prediction was tested by examining sediment-buffering characteristics and spatial variation in SRP among reaches with distinct sediment composition (i.e., fine versus coarse particles) in two tributaries of Boulder Creek, a headwater stream in central Wisconsin. SRP concentrations were significantly lower and algal available P and P sorption capacity were significantly higher in the reach dominated by fine sediments. Although fine particles such as sand had the greatest P sorption capacity, no retention could be attributed to biotic processes, whereas over 50% of P retention in coarse particles such as gravel could be linked to biotic uptake. Equilibrium P concentration (EPC0) assays from different sediment fractions also indicate that biotic uptake is relatively unimportant in sand particles (EPClive 10 μg/L: EPCkilled 10 μg/L) but very important in gravel or larger particles (EPClive 10 μg/L: EPCkilled 80 μg/L). Thus, sediment influence on stream water P concentrations can shift predictably from abiotic sorption in reaches with fine particles to biotic retention in areas dominated by coarse sediments. Consequently, changes in sediment composition due to natural or anthropogenic disturbance have the potential to alter the type and strength of sediment-associated processes determining ambient stream P concentrations.
Isothermal Titration Calorimetry of Membrane Proteins – Progress and Challenges

Integral membrane proteins, including G protein-coupled receptors (GPCR) and ion channels, mediate diverse biological functions that are crucial to all aspects of life. The knowledge of the molecular mechanisms, and in particular, the thermodynamic basis of the binding interactions of the extracellular ligands and intracellular effector proteins is essential to understand the workings of these remarkable nanomachines. In this review, we describe how isothermal titration calorimetry (ITC) can be effectively used to gain valuable insights into the thermodynamic signatures (enthalpy, entropy, affinity, and stoichiometry), which would be most useful for drug discovery studies, considering that more than 30% of the current drugs target membrane proteins. This article is part of a Special Issue entitled: Structural and biophysical characterisation of membrane protein-ligand binding.
Optimization of active regions in midinfrared lasers

The ideal performance of bulk, quantum well, and superlattice active regions for III–V interband midinfrared lasers are compared according to the maximum net gain per unit current density. Based on this figure of merit, which is appropriate for high-power as well as near-threshold operation, InAsSb quantum well active regions should have an order of magnitude lower threshold current than bulk InAs at room temperature. Optimized four-layer superlattices based on the InAs/GaInSb material system, however, should have two to ten times lower threshold currents than the quantum well active regions. Optimal thicknesses for these active regions were evaluated assuming a separate confinement region design. For the four-layer superlattices the optimal thickness is substantially thinner than has been commonly grown: 3 periods rather than 40 periods.
Cpc2, a Fission Yeast Homologue of Mammalian RACK1 Protein, Interacts with Ran1 (Pat1) Kinase To Regulate Cell Cycle Progression and Meiotic Development

The Schizosaccharomyces pombe ran1/pat1 gene regulates the transition between mitosis and meiosis. Inactivation of Ran1 (Pat1) kinase is necessary and sufficient for cells to exit the cell cycle and undergo meiosis. The yeast two-hybrid interaction trap was used to identify protein partners for Ran1/Pat1. Here we report the identification of one of these, Cpc2. Cpc2 encodes a homologue of RACK1, a WD protein with homology to the β subunit of heterotrimeric G proteins. RACK1 is a highly conserved protein, although its function remains undefined. In mammalian cells, RACK1 physically associates with some signal transduction proteins, including Src and protein kinase C. Fission yeast cells containing a cpc2 null allele are viable but cell cycle delayed. cpc2Δ cells fail to accumulate in G1 when starved of nitrogen. This leads to defects in conjugation and meiosis. Copurification studies show that although Cpc2 and Ran1 (Pat1) physically associate, Cpc2 does not alter Ran1 (Pat1) kinase activity in vitro. Using a Ran1 (Pat1) fusion to green fluorescent protein, we show that localization of the kinase is impaired in cpc2Δ cells. Thus, in parallel with the proposed role of RACK1 in mammalian cells, fission yeast cpc2 may function as an anchoring protein for Ran1 (Pat1) kinase. All defects associated with loss of cpc2 are reversed in cells expressing mammalian RACK1, demonstrating that the fission yeast and mammalian gene products are indeed functional homologues.
A typology of strategic alliances in the airline industry: propositions for stability and duration

Abstract While strategic alliances have become commonplace in the airline industry, the stability and performance of these alliances remains questionable. In this article, the authors review the structure of recent alliances in the airline industry and propose a typology of alliances based on two key dimensions: commitment of resources and complexity of arrangement. Using this typology, the authors derive a series of propositions on the stability and duration of various types of alliances.
Errors in climate datasets and their effects on statistical crop models

Abstract Although weather data are widely acknowledged to contain measurement errors, the implications of these errors for models that relate weather to yields have not been adequately examined. From statistical theory and applications in many other fields, it is clear that measurement error in a single predictor variable can lead to bias in estimating the effects of that variable, as well as any other correlated predictors. Of particular concern for statistical crop models is that errors in measuring precipitation can lead to bias in inferences about yield responses to both temperature and precipitation. In this study, simulation extrapolation (SIMEX) is used to gauge the importance of measurement error for two recent studies that employed statistical crop models. In both cases, estimates of yield responses to temperature were only slightly changed when considering measurement errors. However, yield responses to precipitation were significantly larger when assuming that precipitation is measured with 30% error, compared to the common assumption of error-free measurements. Thus, results indicate that studies that ignore measurement errors are unlikely to be biased for estimating T sensitivity of yields, but can easily underestimate P sensitivity by a factor of two or more. More work is needed to test effects of measurement errors in other cases, as well as to better quantify the magnitudes of errors in weather measurements for cropped regions. As a rough substitute for detailed measurement error analysis, sensitivity tests that double the yield response to precipitation are advised when applying statistical crop models to projections from climate ensembles. Depending on the magnitude of precipitation projections, which in turn depend on the spatial and temporal scale of analysis, the conclusions of a study may or may not be altered by considering the effects of measurement errors.
Evaluating Interactions between Groundwater and Vadose Zone Using the HYDRUS-Based Flow Package for MODFLOW

In the past, vadose zone processes in groundwater flow models were dramatically simplified (or even neglected) due to constraints on computational resources. The one-dimensional unsaturated flow package HYDRUS, recently developed for the groundwater model MODFLOW, was evaluated and compared with other contemporary modeling approaches used to characterize vadose zone effects in groundwater models. Being fully incorporated into the MODFLOW program, the HYDRUS package provides MODFLOW with recharge fluxes at the water table, while MODFLOW provides HYDRUS with the position of the groundwater table that is used as the bottom boundary condition in the package. The performance of the HYDRUS package was analyzed for three case studies of increasing complexity: (i) a one-dimensional infiltration experiment; (ii) a two-dimensional water table recharge experiment; and (iii) a hypothetical regional-scale groundwater flow problem. The computational need and modeling efficiency of the HYDRUS package was compared with other relevant MODFLOW packages (VSF, UZF1, and REC-ET). For smaller scale problems (up to two dimensions), the VSF process and the HYDRUS and UZF1 packages performed comparably well in terms of modeling efficiency and simulation times. Because of the high computational demand, it was not feasible to use the VSF process on a typical personal computer for the hypothetical large-scale groundwater problem. The HYDRUS package provided a much more efficient alternative to VSF for this large-scale groundwater problem and could better account for vadose zone processes than the UZF1 and REC-ET packages. For large-scale groundwater problems, the HYDRUS package provides an optimal tradeoff between computational effort and accuracy of model simulations for coupled vadose zone–groundwater problems.
Editorial Notes: Exhibition Complex: Displaying People, Identity, and Culture

Editorial Notes on section relating to submissions from the symposium Exhibition Complex: Displaying People, Identity, and Culture held October 18-20, 2012 at the Carnegie Museum of Art, Pittsburgh, Pennsylvania.
Interview by Jorge Pontual —Sensual Mathematics

[A “Milenio” (Millennium) program interview (interviews with thinkers who are shaping the third millennium) broadcast by Globo News TV in Brazil in June 2001. This is my third and latest TV interview, and it was filmed at my home, mostly in the back garden, and begins and ends with a close-up of the cover of my book The Unknowable. The Globo News TV channel is broadcast in Brazil and simultaneously webcast to the rest of the world, so I was able to see this program on my PC in NY at the same time that it was on TV in Brazil!]
An Integrative Economic Optimization Approach to Systems Development Risk Management

Despite significant research progress on the problem of managing systems development risk, we are yet to see this problem addressed from an economic optimization perspective. Doing so entails answering the question: What mitigations should be planned and deployed throughout the life of a systems development project in order to control risk and maximize project value? We introduce an integrative economic optimization approach to solving this problem. The approach is integrative since it bridges two complementary research streams: one takes a traditional microlevel technical view on the software development endeavor alone, another takes a macrolevel business view on the entire life cycle of a systems project. Bridging these views requires recognizing explicitly that value-based risk management decisions pertaining to one level impact and can be impacted by decisions pertaining to the other level. The economic optimization orientation follows from reliance on real options theory in modeling risk management decisions within a dynamic stochastic optimization setting. Real options theory is well suited to formalizing the impacts of risk as well as the asymmetric and contingent economic benefits of mitigations, in a way that enables their optimal balancing. We also illustrate how the approach is applied in practice to a small realistic example.
Robotic deposition of model hydroxyapatite scaffolds with multiple architectures and multiscale porosity for bone tissue engineering

Model hydroxyapatite (HA) scaffolds with porosities spanning multiple length scales were fabricated by robocasting, a solid freeform fabrication technique based on the robotic deposition of colloidal pastes. Scaffolds of various architectures including periodic, radial, and superlattice structures were constructed. Macropores (100-600 microm) were designed by controlling the arrangement and spacing between rods of HA. Micropores (1-30 microm) and submicron pores (less than 1 microm) were produced within the rods by including polymer microsphere porogens in the HA pastes and by controlling the sintering of the scaffolds. These model scaffolds may be used to systematically study the effects of scaffold porosity on bone ingrowth processes both in vitro and in vivo.
Is metastasectomy for urothelial carcinoma worthwhile

Three decades ago, I saw a man with a large groin mass that proved on biopsy to be urothelial carcinoma. Six years earlier, I had done a radical cystectomy and pelvic lymph node dissection for organ-confined bladder cancer. As this was the only site of disease, I performed a radical groin dissection, encouraged by the fact that surgeons at my institution operated regularly to remove metastatic cancers of the colon, breast, lung, kidney, and bone as well as sarcomas. Why not metastatic bladder cancer? In 1983, when methotrexate, vinblastine, doxorubicin (Adriamycin), and cisplatin (M-VAC) was established as effective chemotherapy against urothelial cancer, we began, where possible, to surgically resect all metastatic sites of disease [1]. In our original M-VAC series of 25 patients, 13 had complete resection of viable tumor (4 survived 5 yr), and postchemotherapy surgery evolved to become routine for unresectable or metastatic bladder cancer. Of 276 patients who received cisplatin-based chemotherapy, 89 (32%) underwent postchemotherapy surgery (8 patients were unresectable). Most patients had resection of metastatic pelvic and retroperitoneal lymph nodes or soft tissue masses, but some had resection of visceral metastases involving liver, lung, or bone. Thirty patients (34%) survived 3–5 yr after postchemotherapy surgery. In 27 patients (33%), no viable tumor was found, pathologically confirming a complete response to chemotherapy. In 54 patients (67%), residual, viable cancer was completely resected; 18 patients (33%)
The Future of Teaching Surgical Endoscopy

Gastrointestinal surgery, with its emphasis on endoscopy, has renewed interest in teaching surgical endoscopy. The field is rapidly evolving, with innovative techniques emanating from the laboratory to the operating room and endoscopy suite. To ensure that surgeons spearhead the field of endoscopic surgery, a new strategy for teaching surgical endoscopy to residents and practicing surgeons must be developed.
Combustion aerosols: factors governing their size and composition and implications to human health.

ABSTRACT Particulate matter (PM) emissions from stationary combustion sources burning coal, fuel oil, biomass, and waste, and PM from internal combustion (IC) engines burning gasoline and diesel, are a significant source of primary particles smaller than 2.5 μm (PM2.5) in urban areas. Combustion-generated particles are generally smaller than geologically produced dust and have unique chemical composition and morphology. The fundamental processes affecting formation of combustion PM and the emission characteristics of important applications are reviewed. Particles containing transition metals, ultrafine particles, and soot are emphasized because these types of particles have been studied extensively, and their emissions are controlled by the fuel composition and the oxidant-tem-perature-mixing history from the flame to the stack. There is a need for better integration of the combustion, air pollution control, atmospheric chemistry, and inhalation health research communities. Epidemiology has demonstrated t...
Optimized shapes of oscillating resonators for generating high-amplitude pressure waves

Several studies have proved that the geometry of an oscillating acoustic resonator strongly influences its resonance frequencies and the nonlinear standing pressure waveform generated within the cavity. The research presented herein uses a quasi-one-dimensional numerical model to solve the acoustic field and is validated by comparing with experimental results. A quasi-Newton type numerical scheme is used to optimize the axisymmetric cavity contour by maximizing the pressure compression ratio, defined as the ratio of maximum to minimum gas pressure at one end of the oscillating resonator. Cone, horn-cone, and cosine resonator contours are each optimized for a fixed amplitude of the periodic external force oscillating the cavity. Different optimized shapes are found when starting with different initial guesses, indicating multiple local extrema. The maximum pressure compression ratio value of 48 is found in an optimized horn-cone shape. This represents a 241% increase in the compression ratio over any previously published results.
Prevalence and Seasonal Distribution of Norovirus Detection in Stools Submitted From Pediatric Patients for Enteric Pathogen Testing

The prevalence and seasonal distribution of norovirus infection in children is not well defined. In this study, stool specimens from children suspected of having gastroenteritis were evaluated for the presence of norovirus. When tested retrospectively, 17.4% of samples were positive, primarily with Genogroup GII, peaking in fall and winter.
Laser Induced Fluorescence Spectroscopy of the Hydroxyl Radical

Abstract The hydroxyl radical has been generated by the excimer laser photolysis of nitrous acid at 248 nm. Rotationally-resolved excitation spectra in the wavenumber range 32170–32745 cm−1 of the hydroxyl (OH) radical obtained by the Laser Induced Fluorescence (LIF) technique have been assigned. The excitation spectra have been recorded both for a static precursor and a supersonic jet expansion. Jet-cooled spectra of the OH radical exhibit rotational cooling and allow comparison with the static cell spectra in terms of population distributions of low-lying rotational levels.
Complexity of Decision-Making in a Nursing Home

Abstract Since the Patient Self-Determination Act became law in 1991, nursing homes routinely address advance directives with all residents. This study investigated the implementation of end-of-life care wishes of residents in one nursing home in Florida. Data were collected from the medical records of residents who died in the facility (n = 75) in one year. Two-thirds of the residents had either completed a living will, or designated a health care decision-maker, and 90.7% of the residents had do-not-resuscitate orders. Findings suggest that in 94% of the cases advance directives were followed, and that professional social work activities contributed to the high rate of compliance.