cssi/SciSciGPT-SciSciNet huggingface dataset:
Covariance matrix estimators and tests of market efficiency

Abstract This paper carries out multi-currency, multi-horizon and combined tests of simple market efficiency using alternative covariance matrix estimators whose finite sample performances have been examined elsewhere in the literature. The data utilized are properly aligned weekly exchange rates from June 1973 to December 1994 on bid spot, 1-month, 3-month and 6-month ask forward rates for several currencies. The results demonstrate that tests of market efficiency are sensitive to the information set specified, the prediction horizon considered and the covariance matrix estimator employed. In most but not all cases, rejections of market efficiency are overturned using a prewhitened heteroskedasticity and autocorrelation consistent covariance matrix estimator with optimal asymptotic properties and better finite sample performance.
Fourteen Things to Look for When Hiring New Staff in Interlibrary Loan/Document Delivery

As library employees retire or move on to other positions, library managers can take advantage of these opportunities to assess how well the vacant job's duties mesh with current organizational goals and needs. Positions in interlibrary loan and document delivery services (ILL/DDS) are no different. They should be evaluated and reviewed each time a vacancy needs to be filled to ensure that the expectations of the position are in line with the goals of the ILL/DDS department and the library.
Strategic Research Partnerships for Exploration

NASA s Space Product Development Program has completed a significant transformation from an industry driven program focused on the commercial use of space, to a NASA space exploration driven program focused on providing research and technologies for space exploration through leveraged research partnerships. Initiated in 1985 under the NASA Office of Commercial Programs, the Space Product Development Program and associated Research Partnership Centers have worked with private industry to fulfill the NASA objective of ". . .enabling io the maximum extent possible the fullest commercial use of space." In 2001, the program began to place greater emphasis on dual use activities. In particular, those activities that enable commercial use of space, while at the Same time fulfill a NASA mission need. With the President s exploration, announcement in January 2004, the transformation of the Space Product Development program further focused on NASA exploration requirements. The Program s experience in successfully assisting industry with technology maturation is now being utilized by the Agency to affordably develop the technologies needed for sustainable human and robotic space exploration.
A longitudinal study of stress-buffering effects for urban African-American male adolescent problem behaviors and mental health

The stress-buffering hypothesis was explored longitudinally in a sample of 173 urban, male, African-American adolescents. Data on parental and friend support, stressful life events, alcohol and substance use, delinquency, and psychological symptoms were collected twice, six months apart. No support for the stress-buffering hypothesis was found for any of the dependent variables. Friend support also was unrelated to the dependent variables longitudinally. Parental support predicted less anxiety and depression longitudinally, but psychological symptoms did not predict increased parental support over time. The findings suggest that parental support may help insulate these African-American youths from anxiety and depression, but that the youths' symptoms do not necessarily activate increased levels of parental support. The results of this study add to the growing body of research that indicates the positive role parental support plays in the healthy development of African-American adolescents. © 2000 John Wiley & Sons, Inc.
Pharmacologic control of pemoline induced self-injurious behavior in rats.

Abstract Administration of oral pemoline produces long lasting amphetamine-type stereotyped behavior and persistent self-biting behavior in rats. The effects of haloperidol, pimozide, diazepam, and serotonin depletion by pretreatment with p-chlorophenylalanine (PCPA) or chronic pretreatment with p-chloroamphetamine (PCA) on abnormal behavior produced by pemoline were studied. Diazepam consistently increased the duration of stereotyped behavior. It also reduced licking/biting amd self-biting but the latter effects were not consistent. Pretreatment with PCA had negligible effects on stereotyped behavior. Pretreatment with PCPA dramatically increased locomotion and rearing without affecting the other components of stereotypy—stereotyped head movements, licking/biting, and self-biting. Haloperidol (0.2 and 0.3 mg/kg) produced a dose related normalization of pemoline induced behaviors, including elimination of self-biting. Pimozide (0.5, 0.8 and 1.3 mg/kg) had little or no effect on behaviors such as locomotions, rears, licking/biting, or stereotyped head movements but eliminated self-biting at 1.3 mg/kg. These data suggest that pemoline, like amphetamine, produces stereotyped behavior through central dopaminergic mechanisms. Dopaminergic mechanisms also appear to be involved in pemoline induced self-biting. Pemoline is apparently pharmacologically and behaviorally very similar to amphetamine. Pemoline may provide a useful animal model for syndroms characterized by self-injurious behavior and other repetitive behaviors.
Transcriptional regulation of the cystathionine-β-synthase gene in Down syndrome and non–Down syndrome megakaryocytic leukemia cell lines

Children with Down syndrome (DS) with acute myeloid leukemia (AML) have significantly higher event-free survival rates compared to those with non-DS AML, linked to greater cytosine arabinoside (ara-C) sensitivity and higher transcript levels of the chromosome 21-localized gene, cystathionine-beta-synthase (CBS), in DS myeloblasts. In this study, we examined the transcriptional regulation of the CBS gene in the DS megakaryocytic leukemia (AMkL) cell line, CMK, characterized by significantly higher CBS transcripts compared with the non-DS AMkL cell line, CMS. Rapid amplification of 5'-cDNA ends (5'-RACE) analysis demonstrated exclusive use of the CBS -1b promoter in the cell lines, and transient transfections with the full-length CBS -1b luciferase reporter gene construct showed 40-fold greater promoter activity in the CMK than CMS cells. Electrophoretic mobility shift assays showed enhanced binding of the transcription factors Sp1/Sp3 to 2 GC/GT-box elements (GC-f and GT-d) in the upstream regions of the CBS -1b promoter in CMK nuclear extracts and undetectable binding in CMS cells. Mutation of the GC-f- or GT-d-binding site resulted in an approximately 90% decrease of the CBS -1b promoter activity in transient transfections of CMK cells. Chromatin immunoprecipitation assays confirmed in vivo binding of Sp3, USF-1, and nuclear factor YA (NF-YA) to the CBS -1b promoter region in chromatin extracts of CMK and CMS cells. Decreased binding of Sp1/Sp3 in CMK nuclear extracts following treatment with calf alkaline phosphatase suggested a role for phosphorylation of Sp1/Sp3 in regulating CBS promoter activity and in the differential CBS expression between CMK and CMS cells. The results of this study with clinically relevant cell line models suggest potential mechanisms for disparate patterns of CBS gene expression in DS and non-DS myeloblasts and may, in part, explain the greater sensitivity to chemotherapy shown by patients with DS AML.
Kinetics and components of the flash photocurrent of isolated retinal rods of the larval salamander, Ambystoma tigrinum.

1. Membrane currents initiated by intense, 20 microseconds flashes (photocurrents) were recorded from isolated salamander rods by combined extracellular suction electrodes and intracellular tight-seal electrodes either in current or voltage clamp mode. The magnitudes (mean +/- 2 S.E.M.) of the maximal photoresponses recorded by the suction and by the intracellular electrode respectively were 40 +/- 5 pA (n = 18) and 35 +/- 7 mV (n = 8) for current clamp at zero current; 43 +/- 9 pA and 66 +/- 13 (n = 11) pA for voltage clamp at the zero-current holding potential, -24 +/- 3 mV. 2. Photocurrents initiated by flashes isomerizing 0.1% or more of the outer segment's rhodopsin achieved a saturated velocity and were 95% complete in less than 50 ms. The effect of incrementing flash intensity above 0.1% isomerization can be described as a translation of the photocurrent along the time axis towards the origin. Within the interval 0-50 ms the latter two-thirds of the velocity-saturated photocurrent is well described as a single-exponential decay. The decay was much faster in voltage clamp (2.8 +/- 1.2 ms, n = 11) than in current clamp mode (17 +/- 5 ms, n = 17). 3. The initial third of the velocity-saturated photocurrent, occurring over the interval from the flash to the onset of exponential decay, followed about the same time course in current and voltage clamp. The time interval occupied by this initial 'latent' phase decreased with increasing flash intensity and attained an apparent minimum of about 7 ms in response to flashes isomerizing 10% or more of the rhodopsin at ca. 22 degrees C. 4. The hypothesis that the decay of outer segment light-sensitive membrane current is the same in current and voltage clamp was supported by an analysis of the difference between outer segment currents measured successively in the two recording modes. First, the tail of the difference current decayed exponentially with a time constant approximately equal to R x C, where R and C are independently estimated slope resistance and capacitance of the rod. Secondly, the integral of the difference current, when divided by outer segment capacitance, closely approximated the hyperpolarizing light response measured under current clamp. Thus, displacement current accounted for the difference between photocurrents measured in current and voltage clamp.(ABSTRACT TRUNCATED AT 400 WORDS)
Volume of RBCs, 24‐ and 48‐hour posttransfusion survivals, and the lifespan of 51Cr and biotin‐X‐N‐hydroxysuccinimide (NHS)‐labeled autologous baboon RBCs: effect of the anticoagulant and blood pH on 51Cr and biotin‐X‐NHS elution in vivo

BACKGROUND: The RBC injury that occurs during collection of the first few milliliters of blood into the pH 5.0 ACD (NIH, Formula A) is referred to as the lesion of collection. The RBC injury was evaluated by labeling the ACD RBCs with 51Cr and measuring the 24-hour posttransfusion survival. The effect of the acidification of ACD blood on the in vivo elution of 51Cr from the RBC has not been reported. STUDY DESIGN AND METHODS: Baboon blood was collected in heparin and in ACD and CP2D at different ratios of blood to anticoagulant. ACD blood with a pH of 5.7 to 6.9 was labeled with 51Cr. Heparinized blood with a pH of 7.4 was labeled with biotin-X-N-hydroxysuccinimide (NHS). ACD blood with a pH of 5.9 was labeled with both 51Cr and biotin-X-NHS. The RBC volumes, 24- and 48-hour posttransfusion survivals, and lifespans (T50) were measured. RESULTS: The RBC volume of ACD blood with a pH ranging from 5.7 to 6.9 was not affected by 51Cr labeling. 51Cr-labeled ACD blood with a pH of 6.9 had an RBC volume that was significantly greater than that seen in heparinized blood with a pH of 7.4 labeled with biotin-X-NHS. In vivo elution of 51Cr from the RBCs prepared from the ACD blood with a pH of 5.7 to 6.9 and in vivo elution of biotin-X-NHS from RBCs prepared from ACD blood with a pH of 5.9 were associated with reductions in 24- and 48-hour posttransfusion survivals and T50. CONCLUSIONS:The anticoagulant and the pH of the medium in which the RBCs were labeled with 51Cr or biotin-X-NHS affected in vivo elution of the label from the RBCs and may reduce posttransfusion survival values.
Lyα-driven outflows around star-forming galaxies

We present accurate Monte Carlo calculations of Lyα radiation pressure in a range of models which represent galaxies during various epochs of our Universe. We show that the radiation force that Lya photons exert on hydrogen gas in the neutral intergalactic medium (IGM), that surrounds minihaloes that host the first stars, may exceed gravity by orders of magnitude and drive supersonic winds. Lya radiation pressure may also dominate over gravity in the neutral IGM that surrounds the H II regions produced by the first galaxies. However, the radiation force is likely too weak to result in supersonic outflows in this case. Furthermore, we show that Lya radiation pressure may drive outflows in the interstellar medium of star-forming galaxies that reach hundreds of kilometres per second. This mechanism could also operate at lower redshifts z ≤ 6, and may have already been indirectly detected in the spectral line shape of observed Lya emission lines.
Evaluation of the potential role of color-coded tissue Doppler echocardiography in the detection of allograft rejection in heart transplant recipients

Abstract Background Color-coded tissue Doppler (TD) echocardiography can noninvasively quantify alterations in left ventricular (LV) systolic and diastolic function. The objective of this study was to test the hypothesis that TD may play a role in the detection of LV dysfunction associated with allograft rejection in heart transplant recipients. Methods and Results Seventy-eight consecutive transplant recipients underwent 89 TD studies of posterior wall myocardial velocity gradient and mitral annular velocity within 1 hour of endomyocardial biopsy. Color TD echocardiographic images were digitized for semiautomated computer analysis. Histologic analysis revealed no significant rejection in 75 biopsies and significant rejection in 14. TD posterior wall peak systolic and diastolic velocity gradients were reduced significantly with rejection: 3.9 ± 2.0 s –1 versus 2.6 ± 0.9 s –1 and 5.4 ± 2.4 s –1 versus 3.5 ± 1.6 s –1 , respectively ( P P 135 mm/s had 93% sensitivity, 71% specificity, and 98% negative predictive value for detecting rejection. Although TD was unable to discriminate between rejection and other causes of low velocity values, high TD velocity values were supportive of excluding rejection. Conclusions These data suggest that color-coded TD may play a potential role as a screening test to exclude rejection in heart transplant recipients. Although this method has the potential to decrease the number of biopsies, further testing in a larger series of transplant recipients with rejection is warranted. (Am Heart J 1999;138:721-30.)
Localization of targets by strabismic subjects: contrasting patterns in constant and alternating suppressors

Strabismic subjects in whom vision in one eye is constantly suppressed localized targets at different points in space when using each eye. Whether they were esotropes or exotropes determined the relation between the two locations and the angle of their vergence error correlated with the magnitude of the interocular discrepancy. These relationships suggest that constant suppressors utilize information about posture of the dominant eye in reaching toward targets presented to the normally suppressed eye. Neither orthotropes nor strabismics in whom vision in each eye is alternately suppressed showed this anomaly. These results were attributed to differences in the way in which visual space is represented, an outcome of the pattern of use of the eyes during early development.
GaN/InGaN Heterojunction Bipolar Transistors With $f_{T} > \hbox{5}\ \hbox{GHz}$

We report GaN/InGaN n-p-n double-heterojunction bipolar transistors with the collector current density (JC) >; 16 kA/cm2 and the current gain (β) >; 24 grown on a sapphire substrate. The cutoff frequency (fT) of greater than 5 GHz and the maximum oscillation frequency (fmax) of 1.3 GHz are also measured for a GaN/InGaN heterojunction bipolar transistor at JC = 4.7 kA/cm2.
Optimal recovery of 3D X-ray tomographic data via shearlet decomposition

This paper introduces a new decomposition of the 3D X-ray transform based on the shearlet representation, a multiscale directional representation which is optimally efficient in handling 3D data containing edge singularities. Using this decomposition, we derive a highly effective reconstruction algorithm yielding a near-optimal rate of convergence in estimating piecewise smooth objects from 3D X-ray tomographic data which are corrupted by white Gaussian noise. This algorithm is achieved by applying a thresholding scheme on the 3D shearlet transform coefficients of the noisy data which, for a given noise level e, can be tuned so that the estimator attains the essentially optimal mean square error rate O(log(e − 1)e2/3), as e→0. This is the first published result to achieve this type of error estimate, outperforming methods based on Wavelet-Vaguelettes decomposition and on SVD, which can only achieve MSE rates of O(e1/2) and O(e1/3), respectively.
Peroxides and the survivability of microorganisms on the surface of Mars.

This paper discusses the possibility that any terrestrial microorganisms brought to Mars might survive the unhospitable environment of that planet, with special attention given to the effects of highly oxidizing material that is now known to cover the Martian surface. Data obtained by the gas exchange experiment on Viking indicate that, if all of the released oxygen is assumed to come from H2O2, the concentrations of H2O2 on Mars range from 25 to 250 ppm. Laboratory data indicate that certain soil bacteria are able to survive and grow to stationary phase at H2O2 concentrations as high as 30,000, indicating that, if there is H2O2 at the level of 250 ppm or even an order of magnitude greater on the Martian surface, this fact alone would not make the surface of Mars self-sterilizing.
La resistencia andina: Cayambe, 1500‐1800

La resistencia andina: Cayambe, 1500-1800. Galo Ramon. Quito: Centro Andino de Accion Popular/FLACSO, 1987. 284 pp. n.p.
Componential Skills in Early Spelling Development in Korean

The present study investigated multiple componential skills for conventional spelling using data from 5-year-old Korean children (N = 77). Error analysis showed that 5-year-old Korean children primarily employed a phonological transcription strategy in spelling despite the absence of systematic and explicit instruction on phonological strategies (i.e., phonological awareness and alphabetic knowledge). Results from regression analysis revealed that alphabetic knowledge, orthographic awareness, and morphological awareness were positively related to spelling after controlling for vocabulary and phonological awareness. These results converge with previous studies with English-speaking children showing the importance of multiple skills such as alphabetic skills (phoneme awareness and letter knowledge), orthographic awareness, and morphological awareness for early spelling development.
Relativistic Theory of Fermions and Classical Fields on a Collocation Lattice

Abstract We present a novel numerical method for solving dynamical strong field problems in quantum mechanics and classical field theory based on expansion of functions in terms of splines. The method differs from traditional approaches by the introduction of a mapping onto a collocation lattice, which is generally nonuniform and time dependent depending on the particular physical application. This approach results in a set of finite matrix transformations of a type which can be evaluated rapidly on supercomputers possessing either vector or matrix coprocessors. As an example of the method, we present a study of the relativistic quantum-mechanical many-electron problem interacting via very strong time-dependent classical fields.
An Oyster Spat (1921) with Mature Male Sexual Products.

IN the course of experiments carried out this year (1921) on the rate of growth of the slipper-limpet in the River Blackwater, Essex, I obtained a number of oyster spat on shells put in a floating raft and on clean scallop shells which were put in the water on June 9. These clean scallop shells were strung out on tarred rope at low water and kept suspended above the ground by tying the rope to stout branches of trees driven vertically into the ground. On November 16 the shells were taken out of the raft and from the shore and the new summer growth, including young oysters, examined and measured. Many of the young oyster spat measured about an inch in diameter (length anatomically) and an inch in depth (height anatomically). Some of these living spat were examined microscopically on the beds, and a few were taken back to the Plymouth Laboratory for careful examination in the living state.
Spectral Decomposition of 3-D Ground Penetrating Radar Data From the Norman Landfill

The application of spectral decomposition analysis to seismic data is quickly gaining momentum in the oil industry. Encouraged by this momentum, and taking advantage of the fact that seismic algorithms are widely used for ground-penetrating radar (GPR), we applied spectral decomposition to our GPR data. The object of this research was to integrate the spectral decomposition results with complex attributes, sediment core data, and conductivity logs in order to make a more robust interpretation. The proposition tested was that spectral decomposition would help to identify the anomalously high attenuation associated with clay layers, and highlight other effects, such as preferential illumination of specific features due to tuning effects and amplitude changes due to differences in electric impedance. The goal was to integrate the spectral decomposition results with the other data available (cores with grain size analysis and conductivity data), and draw some observations from the application of this analysis tool to GPR data.
Channels formed by colicin E1 in planar lipid bilayers are large and exhibit pH-dependent ion selectivity.

The E1 subgroup (E1, A, Ib, etc.) of antibacterial toxins called colicins are known to form voltage-dependent channels in planar lipid bilayers. The genes for colicins E1, A and Ib have been cloned and sequenced, making these channels interesting models for the widespread phenomenon of voltage dependence in cellular channels. In this paper we investigate ion selectivity and channel size—properties relevant to model building. Our major finding is that the colicin E1 channel is large, having a diameter ofat least 8 A at its narrowest point. We established this from measurements of reversal potentials for gradients formed by salts of large cations or large anions. In so doing, we exploited the fact that the colicin channel is permeable to both cations and anions, and its relative selectivity to them is a functions and anions, and its relative selectivity to them is a function of pH. The channel is anion selective (Cl− over K+) in neutral membranes, and the degree of selectivity is highly dependent on pH. In negatively charged membranes, it becomes cation selective at pH's higher than about 5. Experiments with pH gradients cross the membrane suggest that titratable groups both within the channel lumen and near the channel ends affect the selectivity. Individual E1 channels have more than one open conductance state, all displaying comparable ion selectivity. Colicins A and Ib also exhibit pH-dependent ion selectivity, and appear to have even larger lumens than E1.
Pressure dependent yield criteria for polymers

Summary Y M Different criteria have been proposed to include the influence of pressure (or mean normal stress) on the yield behavior of polymers. It is difficult to distinguish among them using the type of experiments that produce data used in two-dimensional plots of yield loci. This is due to the fact that the maximum range of values of mean normal stress is relatively small in such experiments. Marked differences between these criteria do occur however as the hydrostatic pressure or mean stress is altered substantially. Experiments that show the effect of applied pressure on tensile and/or compressive yield strength provide one means for describing such differences. This paper considers two forms of a pressure modified yon Mises criterion and shows a comparison with available experimental information.
Stimulation-enhanced 3-O-methylglucose efflux from the frog sartorius: kinetics and properties of the system.

Abstract The characteristics of the process by which contraction enhances glucose transport in the frog sartorius were studied. Electrical stimulation increased the permeability of muscle to 3-O-methylglucose (3-O-MeGlc), a nonmetabolizable glucose analogue, increasing efflux as well as uptake. Enhanced efflux was due to an increase in Vmax of the efflux process. A lactacidosis had no effect on basal 3-O-MeGlc efflux, and replacement of media Na+ with Li+ did not affect stimulation-induced uptake. Also, basal and stimulated uptake was not affected by 1 μM 12-O-tetradecanoylphorbol-13-acetate (TPA), a protein kinase C activator. Lastly, N- carbobenzoxy-glycl- l -phenylalaninamide , which inhibits insulin-enhanced, but not basal, glucose uptake in adipocytes, inhibited both basal and stimulated 3-O-MeGlc fluxes in the frog sartorius. From these findings, we conclude: (1) contraction and exercise enhance glucose transport in muscle by increasing the number of transporters in the plasma membrane, or their turnover, by an unknown process: and (2) basal glucose transport of muscle, unlike that of adipocytes, can not be distinguished from stimulated transport on the basis of its insensitivity to N- carbobenzoxylglycyl- l -phenylalaninamide .
Epigenetics of Progression of Chronic Kidney Disease: Fact or Fantasy?

Epigenetic modifications are important in the normal functioning of the cell, from regulating dynamic expression of essential genes and associated proteins to repressing those that are unneeded. Epigenetic changes are essential for development and functioning of the kidney, and aberrant methylation, histone modifications, and expression of microRNA could lead to chronic kidney disease (CKD). Here, epigenetic modifications modulate transforming growth factor β signaling, inflammation, profibrotic genes, and the epithelial-to-mesenchymal transition, promoting renal fibrosis and progression of CKD. Identification of these epigenetic changes is important because they are potentially reversible and may serve as therapeutic targets in the future to prevent subsequent renal fibrosis and CKD. In this review we discuss the different types of epigenetic control, methods to study epigenetic modifications, and how epigenetics promotes progression of CKD.
The effect of biocidal treatments on respiration and enzymatic activities of douglas-fir needle litter

Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) needle-litter was given treatments of varying biocidal severity including air-drying, oven-drying, fumigation with methyl bromide plus chloropicrin. autoclaving, and a control. The litter was inoculated with a small amount of fresh litter homogenate and monitored for CO2 evolution rate and extractable enzymatic activity during a 77-day incubation. Enzymatic activities assayed included cellulase. xylanase, mannase, amylase. invertase, β-glucosidase, protease, polyphenoloxidase and peroxidase. The concentrations of extractable ninhydrin-reactive compounds, glucose, and reducing substances were also determined. Air-drying produced a small, initial stimulation in respiration but had no effect on any enzymatic activity throughout the 77-day incubation except for an initial decrease in polyphenoloxidase and peroxidase activities. Oven-drying produced a substantial loss of all enzymatic activities initially but all carbohydrase and protease activities recovered to greater than control levels by 7 days; after a 1-day lag, oven-drying produced a pronounced stimulation in the rate of CO2 evolution. Autoclaving produced a 2-day lag in a less pronounced (compared to oven-drying) respiratory stimulation: initially all enzymatic activities were destroyed and only protease and β-glucosidase activities recovered to control levels. Fumigation produced a respiratory stimulation after a 9-day lag (probably due to residual chloropicrin) which coincided with a pronounced increase in cellulase. xylanase, mannase and amylase activities: initially, no activities except polyphenoloxidase and peroxidase were adversely affected by fumigation. During the entire incubation, the activities of cellulase. xylanase. mannase. amylase and invertase were highly correlated with each other regardless of treatment. After 77 days, the rates of CO2 evolution of all samples were correlated with the level of amylase and cellulase activity (r = 0.86 and 0.83, respectively). This observation points to the value of enzymatic assays for following the processes which release substrate for microbial assimilation from plant litter. The close association of polysaccharidase and protease activities with the flush of CO2 evolution following biocidal treatment, particularly oven-drying, indicates that the decomposition of carbohydrates and proteins released from microbial biomass or plant litter is a mechanism for this often-observed respiratory stimulation.
Disorder and Interactions in the Hubbard Model

We investigate the single-band repulsive Hubbard model with random site energies as a model for the disordered electron system in the strong-interaction limit. Previous scaling treatments of this problem, pioneered by Finkel’shtein, are based on a perturbative treatment of the interactions and the scaling eventually fails as the couplings become large. We treat the disordered Hubbard model at large repulsion U by a mean-field slave-boson technique coupled with the matrix nonlinear sigma model method to average over the disorder. In first approximation, we find an effective hamiltonian with an attractive coupling inversely proportional to U. A new feature is an enhancement of band narrowing due to the interplay of correlation and disorder. The scaling drives 1/U to weak coupling consistent with the apparent scaling of U to strong coupling in the conventional approach, to which our method is complementary. We find that the conductivity decreases monotonically as the temperature decreases, a new result.
Absence of photodichroism in the retinal receptors.

Abstract We looked for photodichroism in the frog ( Rana pipiens ) retina frozen at −10°C or fixed in gluteraldehyde using the early receptor potential as a probe. No trace of photodichroism was found. It, therefore, appears very unlikely that the lack of photodichroism is due to rotational Brownian motions of the pigment molecules.
Link optimization for energy-constrained wireless networks with packet retransmissions

With the objective to minimize the energy consumption for packet based communications in energy-constrained wireless networks, this paper establishes a theoretical model for the joint optimization of the parameters at the physical layer and data link layer. Multilevel quadrature amplitude modulation (MQAM) and automatic repeat request (ARQ) techniques are considered in the system model. The optimization problem is formulated into a three dimensional nonlinear integer programming (NIP) problem with the modulation order, packet size, and retransmission limit as variables. For the retransmission limit, a simple search method is applied to degenerate the three dimensional problem into a two dimensional NIP problem, for which two optimization algorithms are proposed. One is the successive quadratic programming (SQP) algorithm, combining with the continuous relaxation based branch-and-bound method, which can obtain the global optimal solution since the continuous relaxation problem is proved to be hidden convex. The other is a low-complexity sub-optimal iterative algorithm, combining with the nearest-neighboring method, which can be implemented with a polynomial complexity. Numerical examples are given to illustrate the optimization solution, which suggests that the joint optimization of the physical/data link layer parameters contributes noticeably to the energy saving in energy-constrained wireless networks. Copyright © 2010 John Wiley & Sons, Ltd.
Hyperkalemia and liver transplantation

Background Hyperkalemia poses serious hazards to patients undergoing orthotopic liver transplantation (OLT), and its predictors have not been thoroughly examined. Methods We retrospectively studied 1124 consecutive adult patients who underwent OLT. Hyperkalemia was defined as serum K+ > or =5.5 mmol/L. A total of 47 recipient, donor, intraoperative, and laboratory variables were initially analyzed in univariate analyses. Independent predictors of hyperkalemia in three periods of OLT (prereperfusion, early postreperfusion, and late postreperfusion) were determined in multivariate logistic regression analyses. Results Of 1124 patients, 10.2%, 19.1%, and 7.9% had hyperkalemia in the prereperfusion, early postreperfusion, and late postreperfusion periods, respectively. Higher baseline K+ and red blood cell transfusion were independent predictors of prereperfusion hyperkalemia. Higher baseline K+ (or prereperfusion K+) and donation after cardiac death donor were independent predictors of early postreperfusion hyperkalemia. Higher baseline K+, longer warm ischemia time, longer donor hospital stay, lower intraoperative urine output, and the use of venovenous bypass were independent predictors of late postreperfusion hyperkalemia. Conclusions Several laboratory, intraoperative, and donor variables were identified as independent predictors of hyperkalemia in the different periods. Such information may be used for more targeted preemptive interventions in patients who are at risk of developing hyperkalemia during adult OLT.
Stimulus value role: A theory of marital choice.

A three-stage theory of marital choice is presented called Stimulus-Value-Role. The first (stimulus) stage consists of value satisfaction obtained by visual, auditory, and non-interactional means. The second (value) stage consists of values appreciated through verbal interaction, and the third (role) stage involves the ability of the couple to function in mutually assigned roles. Among the topics considered are whether similars or opposites marry, sex-drive, self-acceptance, neuroticism, physical attraction, greater importance of men in determining courtship progress, and imagined role-compatibility as opposed to actual role-compatibility. A series of 19 hypotheses and supporting data are presented.
Selective Hepatic Vascular Exclusion versus Pringle Maneuver in Major Liver Resections: Prospective Study

Selective hepatic vascular exclusion (SHVE) and the Pringle maneuver are two methods used to control bleeding during hepatectomy. They are compared in a prospective randomized study, where 110 patients undergoing major liver resection were randomly allocated to the SHVE group or the Pringle group. Data regarding the intraoperative and postoperative courses of the patients are analyzed. Intraoperative blood loss and transfusion requirements were significantly decreased in the SHVE group, and postoperative liver function was better in that group. Although there was no difference between the two groups regarding the postoperative complications rate, patients offered the Pringle maneuver had a significantly longer hospital stay. The application of SHVE did not prolong the warm ischemia time or the total operating time. It is evident from the present study that SHVE performed by experienced surgeons is as safe as the Pringle maneuver and is well tolerated by the patients. It is much more effective than the Pringle maneuver for controlling intraoperative bleeding, and it is associated with better postoperative liver function and shorter hospital stay.
Maternal response to resource limitations in eastern woodrats

Prevailing theories concerning maternal investment strategies to maximize fitness under adverse environmental conditions predict sex-biased investment in offspring under certain circumstances. These predictions have received empirical support in some species but not in others. The present study was designed to assess patterns of maternal investment in postnatally food-restricted eastern woodrats, Neotoma floridana, in an attempt to replicate previous work and to examine patterns of resource allocation in greater detail. Experimental dams received a food ration that supplied approximately 80% of non-lactating nutritional requirements, whereas control dams had unrestricted access to food. To limit the level of stress experienced by lactating mothers, individual females were allowed unlimited access to food for the duration of the lactation period if their mass fell below 75% of their pre-experimental mass. Food restricted dams attempted to rear all offspring despite experiencing considerable weight loss themselves. Growth rates of young from experimental litters were significantly lower than those of young from control litters. In contrast to previously reported data, no evidence of sex-biased maternal investment was found in this species.
Polarization properties of the freely propagating electromagnetic field of arbitrary spatial and temporal form

The angular spectrum of plane waves representation of the freely propagating electromagnetic field in the half-space z ≥ z0 of a homogeneous, isotropic, locally linear, temporally dispersive medium is employed to describe the polarization properties of the field throughout the half-space z > z0 in terms of the polarization behavior of either field vector on the plane at z = z0. Both the spatial and the temporal dependence of the initial field vectors on this plane are assumed to be known but are otherwise arbitrary functions of the transverse position vector rT and time t on that plane. The general relationship between the electric and the magnetic polarization ellipses is obtained, along with the general orthogonality relations between the field vectors. Finally, the conditions under which either or both field vectors may be uniformly polarized are described.
Daily Emotional Dynamics in Depressed Youth: A Cell Phone Ecological Momentary Assessment Study.

This study utilized a new cellular phone ecological momentary assessment approach to investigate daily emotional dynamics in 47 youth with Major Depressive Disorder (MDD) and 32 no psychopathology controls (CON), ages 7 – 17. Information about emotional experience in the natural environment was obtained using answer-only cellular phones while MDD youth received an 8 week course of cognitive behavioral therapy and/or psychopharmacological treatment. Compared to CON youth, MDD youth reported more intense and labile global negative affect, greater sadness, anger, and nervousness, and a lower ratio of positive to negative affect. These differences increased with pubertal maturation. MDD youth spent more time alone and less time with their families than CON youth. Although differences in emotional experiences were found across social contexts, MDD youth were more negative than CON youth in all contexts examined. As the MDD participants progressed through treatment, diagnostic group differences in the intensity and lability of negative affect decreased, but there were no changes in the ratio of positive to negative affect or measures of social context. We discuss methodological innovations and advantages of this approach, including improved ecological validity and access to information about variability in emotions, change in emotions over time, the balance of positive and negative emotions, and the social context of emotional experience.
Evidence of cell loss from the rat retina during senescence.

In order to determine whether neuronal cell death in the retina accompanies senescence, retinas from pigmented ACI rats of various ages were analysed for changes in dimensions, cell densities, DNA content, and rhodopsin levels. Between the ages of 4 and 30 months, there were significant declines in the densities of nuclei in all three nuclear layers of the retina. Over this age span, nuclear density in the outer nuclear layer (ONL) declined by 32–41 %, depending on the region of the retina examined, while inner nuclear layer (INL) nuclear density decreased by 25–34 %. Over the same age range, the nuclear density in the ganglion cell layer (GCL) declined by 25–28 %. The eye increased in size over the 4–30 month age span, particularly between 4 and 12 months. The retinal stretching that resulted from this growth could only partially account for the age-related decline in retinal cell densities. Depending on the region of the retina examined, decreases in nuclear density of 17–26 % for the ONL, 9–17 % for the INL, and 16–20 % for the GCL were apparently due to cell death. Measurements of retinal DNA content support the conclusion that significant cell loss from the retina occurs during senescence; between 4 and 30 months of age retinal DNA content decreased by about 13 %. Age-related changes in retinal rhodopsin content did not parallel apparent changes in photoreceptor number. Between 4 and 11 months of age, rhodopsin levels rose by about 10 %, and then remained constant up to 26 months. Over this same age span, there was an apparent decrease in photoreceptor number of about 15 %. These findings suggest that the amount of rhodopsin per photoreceptor cell increased by up to 25 % between 4 and 26 months of age. Beyond 26 months, rhodopsin levels fell in parallel with photoreceptor cell numbers.
Reversal of coupling in intermetallic compounds containing two rare earth elements

Abstract The reversal in coupling (from antiferromagnetic to ferromagnetic order with increasing x ) in Eu x La 1− x Al 2 ternaries is successfully analyzed in terms of the RKKY formalism. The Fermi wavevector k required to account for the behavior of these ternaries is k = 0.94 k 0 , which is in close agreement with the k -value previously obtained for GdAl 2 and GdAl 2 -based ternaries from NMR work. The similarity of behavior of Gd 0.1 La 0.9 Al 2 and Eu 0.1 La 0.9 Al 2 and their observed Curie temperatures can also be understood using the same theoretical framework and approximately the same k -values.
Locality analysis: a nonillion time window problem

The rise of social media and cloud computing, paired with ever-growing storage capacity are bringing big data into the limelight, and rightly so. Data, it seems, can be found everywhere; It is harvested from our cars, our pockets, and soon even from our eyeglasses. While researchers in machine learning are developing new techniques to analyze vast quantities of sometimes unstructured data, there is another, not-so-new, form of big data analysis that has been quietly laying the architectural foundations of efficient data usage for decades.Every time a piece of data goes through a processor, it must get there through the memory hierarchy. Since retrieving the data from the main memory takes hundreds of times longer than accessing it from the cache, a robust theory of data usage can lay the groundwork for all efficient caching. Since everything touched by the CPU is first touched by the cache, the cache traces produced by the analysis of big data will invariably be bigger than big.In this paper we first summarize the locality problem and its history, and then we give a view of the present state of the field as it adapts to the industry standards of multicore CPUs and multithreaded programs before exploring ideas for expanding the theory to other big data domains.
Investigating electric accidents — The art of forensic investigation (Examining foresight in hindsight)

If one works in the world of electrical safety long enough, taking part in forensic investigations is almost inevitable. Whether one is investigating an electrical incident in-house, or investigating as an expert witness, the nature of forensic investigation is largely the same. Whether analyzing a product failure or advising an attorney, forensic investigations are driven by similar principles and process. The goal is to find the truth, document the facts, find who or what is at fault, advise and educate others, and act to drive a remedy for bad situations. Forensic meaning ‘applying scientific knowledge to legal issues’, implies interaction with that annoying sub-species known as the lawyer. Although often quite knowledgeable regarding the subject matter, few forensic investigators are schooled in the cross-over between the engineering and legal worlds. At the end of the day, the forensic expert is tasked with educating a population unfamiliar with the environment in which the incident occurred and the technology involved in the incident. Forensic investigation starts with fact finding. For the in-house investigator, this may be relatively easy. For the consultant attached to litigation, fact finding is conducted through a formal process called “discovery.” Contrary to what many believe, preserving evidence and avoiding spoliation is the responsibility of everyone involved in the investigation. Once the facts are known, forensic investigators are tasked with developing working theories, answering the unanswered questions, and assigning probabilities to alternative explanations. In complex scenarios, knowing what occurred to the legal standard of “more likely than not” may become more difficult than not. No matter what lawyers and employers tell their forensic team, forensic investigators must remain independent and at times be painfully honest. The worst mistake made during an investigation is trying to develop answers that serve one's client that are contrary to the facts and probabilities. Forensic experts should leave the “circle the wagons” mentality to the attorneys. Many an expert (including this author) has learned the costly lesson that being a “team player” often does not survive the harsh and adversarial environment of the courtroom. Letting the legal team assess litigation risk based on the real truth and non-sugar-coated facts serves the best interests of one's client. Forensic investigators should not play lawyer, should not play adversary, and should not over-invest in the outcome of the investigation. They should do what engineers are trained to do, the way that engineers are trained to do it. In the words of the great Jack Webb, forensic investigation is about “just the facts.”
Comparative studies on liver and kidney xanthine dehydrogenase in two breeds of domestic chicks (Gallus domesticus) during prolonged starvation.

Abstract 1. 1. Breed differences were observed in the response of chick liver xanthine dehydrogenase (XDH) to progressive starvation. 2. 2. Total liver XDH activity was not changed significantly during an 8-day fast in White Leghorn cockerels. 3. 3. This is in contrast to the significant reduction in liver enzyme activity observed after 3 days of fasting in Indian River cockerels. 4. 4. Kidney XDH activity during fasting was not changed appreciably in either breed of chick. 5. 5. Hemoconcentration was largely responsible for the relatively small increase in plasma uric acid levels in broiler-type chicks during starvation but could not explain completely the threefold increase after 8 days of fasting in layer-type chicks.
Effect of advancing velocity and fluid viscosity on the dynamic contact angle of petroleum hydrocarbons

The goal of this research was to study the effect of advancing velocity and liquid viscosity on the dynamic contact angle between a solid surface and various hydrocarbons. The Wilhelmy plate technique was used to measure the dynamic contact angle at advancing velocities between 20 and 264 μm/s. In addition to hydrocarbons, two silicon oils were also tested for comparison purposes. The results indicate that advancing velocity and oil viscosity have a significant effect on the dynamic contact angle for both hydrocarbon and silicon oils. For example, the advancing contact angle for viscous (1540 mPa s at 15 °C) oils was up to 2 times higher at 200 μm/s than at 20 μm/s. As a result, it is recommended that when values for dynamic contact angles are reported, the advancing velocity at which they were measured be indicated. This will ensure correct data interpretation, meaningful comparison between various studies, and better prediction of multiphase flow or adhesion processes that depend on the dynamic contact angle.
Probability Density of the Maximum Likelihood Elevation Estimate of Radar Targets

The probability density of the maximum likelihood estimate of elevation angle of a radar target in the presence of multipath is calculated. For detectable signals that have low signal-to-noise ratios, the density is a mixture of a Gaussian density and a delta function at the horizon.