cssi/SciSciGPT-SciSciNet huggingface dataset:
An Analytical Evaluation of the Log-periodogram Estimate in the Presence of Level Shifts and its Implications for Stock Returns Volatility ∗

Recently, there has been an upsurge of interest on the possibility of confusing long memory and structural changes in level. Many studies have shown that when a stationary short memory process is contaminated by level shifts the estimate of the fractional differencing parameter is biased away from zero and the autocovariance function exhibits a slow rate of decay, akin to a long memory process. We analyze the properties of the autocorrelation function, the periodogram and the log periodogram estimate of the memory parameter when the jump component is specified by a simple mixture model. Our theoretical results explain many findings reported and uncover new features. Simulations are presented to highlight the properties of the distributions and to assess the adequacy of our approximations. Also, we explain how the limit distribution changes as the number of frequencies used varies, unlike the case with a pure fractionally integrated model. We confront this practical implication to daily SP500 absolute returns and their square roots over the period 1928-2002. Our findings are remarkable, the autocorrelations and the path of the log periodogram estimates clearly follows patterns that would obtain if the true underlying process was one of shortmemory contaminated by level shifts instead of a pure fractionally integrated process. A simple testing procedure is also proposed, which reinforces this conclusion.
A hybrid index structure for set-valued attributes using itemset tree and inverted list

The use of set-valued objects is becoming increasingly commonplace in modern application domains, multimedia, genetics, the stock market, etc. Recent research on set indexing has focused mainly on containment joins and data mining without considering basic set operations on set-valued attributes. In this paper, we propose a novel indexing scheme for processing superset, subset and equality queries on set-valued attributes. The proposed index structure is a hybrid of itemset-transaction set tree of "frequent items" and an inverted list of "infrequent items" that take advantage of the developments in itemset research in data mining. In this hybrid scheme, the expectation is that basic set operations with frequent low cardinality sets will yield superior retrieval performance and avoid the high costs of construction and maintenance of item-set tree for infrequent large item-sets. We demonstrate, through extensive experiments, that the proposed method performs as expected, and yields superior overall performance compared to the state of the art indexing scheme for set-valued attributes, i.e., inverted lists.
Alcohol Dependence Genetics: Lessons Learned From Genome-Wide Association Studies (GWAS) and Post-GWAS Analyses.

Background Alcohol dependence (AD) is a complex psychiatric disorder and a significant public health problem. Twin and family-based studies have consistently estimated its heritability to be approximately 50%, and many studies have sought to identify specific genetic variants associated with susceptibility to AD. These studies have been primarily linkage or candidate gene-based, and have been mostly unsuccessful in identifying replicable risk loci. Genome-wide association studies (GWAS) have improved the detection of specific loci associated with complex traits, including AD. However, findings from GWAS explain only a small proportion of phenotypic variance and alternative methods have been proposed to investigate the associations that do not meet strict genome-wide significance criteria.
Multiple mechanisms of age-dependent accumulation of amyloid beta protein in rat brain: Prevention by dietary supplementation with N-acetylcysteine, α-lipoic acid and α-tocopherol

The aged brain may be used as a tool to investigate altered metabolism of amyloid beta protein (Aβ42) that may have implications in the pathogenesis of Alzheimer's disease (AD). In the present study, we have observed a striking increase in the amyloid precursor protein (APP) level in the brain cortex of aged rats (22-24 months) along with a mild but statistically significant increase in the level of APP mRNA. Moreover, the activity of β secretase is elevated (nearly 55%) and that of neprilysin diminished (48%) in brain cortex of aged rats compared to that in young rats (4-6 months). All these changes lead to a markedly increased accumulation of Aβ42 in brain cortical tissue of aged rats. Long-term dietary supplementation of rats with a combination of N-acetylcysteine, α-lipoic and α-tocopherol from 18 months onwards daily till the sacrifice of the animals by 22-24 months, attenuates the age-related alterations in amyloid beta metabolism. In separate experiments, a significant impairment of spatial learning and memory has been observed in aged rats, and the phenomenon is remarkably prevented by the dietary supplementation of the aged animals by the same combination of N-acetylcysteine, α-lipoic acid and α-tocopherol. The results call for further explorations of this combination in suitable animal models in ameliorating AD related brain deficits.
Effect of Host Tree Species on Cellulase Activity and Bacterial Community Composition in the Gut of Larval Asian Longhorned Beetle

Anoplophora glabripennis, the Asian longhorned beetle, is a wood-boring insect that can develop in a wide range of healthy deciduous hosts and requires gut microbes to aid in wood degradation and digestion. Here we show that larval A. glabripennis harbor a diverse gut bacterial community, and this community can be extremely variable when reared in different host trees. A. glabripennis reared in a preferred host (Acer saccharum) had the highest gut bacterial diversity compared with larvae reared either in a secondary host (Quercus palustris), a resistant host (Pyrus calleryana), or on artificial diet. The gut microbial community of larval A. glabripennis collected from field populations on Brooklyn, NY, showed the highest degree of complexity among all samples in this study. Overall, when larvae fed on a preferred host, they harbored a broad diversity of gut bacteria spanning the α-, β-, γ-Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Cellulase activities (β-1,4-endoglucanase, β-1,4-exoglucanase, and β-1,4-glucosidase) in the guts of larvae fed in a preferred host (A. saccharum) or a secondary host (Q. palustris) were significantly higher than that of artificial diet fed larvae. Larvae that fed on wood from a resistant host (P. calleryana) showed suppressed total gut cellulase activity. Results show that the host tree can impact both gut microbial community complexity and cellulase activity in A. glabripennis.
Remote Sensing Phenology

A number of approaches using a variety of satellite remote sensing products have been used to derive metrics related to the timing of biological events (or land surface phenology, LSP). The advantages of utilizing remote sensing for phenology applications are the ability to capture the continuous expression of phenology patterns across the landscape and the ability to retrospectively observe phenology from archived satellite data sets (e.g. Landsat and Advanced Very High Resolution Radiometer). However, LSP databases have not yet been satisfactorily validated due to the difficulty in obtaining sufficiently extensive ground observations throughout the growing season. A multi-level validation approach that uses ground observations, dedicated web cameras, and high, medium, and coarse spatial resolution satellite data is needed to give scientists an improved level of confidence in utilizing the data. Many of these shortcomings are being addressed by phenology networks across the globe such as the U.S. National Phenology Network. Even without extensive validation, a number of applications areas have employed LSP data successfully, including studies on ecosystems analysis, disasters, land use, and climate change. Land surface phenology promises to continue contributing to these types of applications, and will also likely serve as an important early indicator of environmental effects of climate change
The Use of Peer-Pairing in Child Psychotherapy

child chosen for individual treatment may be denied the benefits of interven tions designed to teach social skills and foster peer relationships. With this child, a pairing arrangement with an other child can be extremely effective. Peer-pairing treatment differs from individual and group therapy both in dynamics and theory: It is a unique model offering children with severe social deficiencies an opportunity to develop the skills necessary to make friends. This article presents the con cept of peer-pairing treatment as an alternative and a supplement to indi vidual or group therapy; the rationale for selecting this form of treatment is discussed as well as the types of problems for which it is indicated. Different adaptations of the pairing model and specific therapeutic tech niques, along with a case that illus trates the application of the model, are presented.
Estimation of dynamic relative permeability and capillary pressure from countercurrent imbibition experiments

Direct laboratory measurements of in situ water-phase saturation history are used to estimate relative permeability and capillary pressure functions. The magnitude of so-called nonequilibrium effects during spontaneous imbibition is quantified and, if significant, these effects are incorporated within the estimation technique. The primary constraint employed is that curves must increase or decrease monotonically; otherwise, no predetermined functionality is assumed. The technique is demonstrated using water saturation profile histories obtained for diatomite (a low-permeability and high-porosity rock). Results indicate that nonequilibrium effects detected at laboratory scale in low-permeability rocks influence the estimation of unsteady-state relative permeability and capillary pressure.
Feingold syndrome: microcephaly, esophageal atresia, type III laryngeal cleft, malrotation, limb anomalies.

Feingold Syndrome: Microcephaly, Esophageal Atresia, Type III Laryngeal Cleft, Malrotation, Limb Anomalies
Prediction of escape from a potential well under harmonic excitation

Abstract Non-linear dynamical systems are considered which are conservative except for the presence of viscous damping. The systems are initially at rest in a potential well. Harmonic excitation is applied, and approximate conditions for escape from the potential well are sought. A method is described which uses the harmonic-balance technique to obtain an approximate motion, and then compares the maximum energy during that motion with the potential barrier. Numerical results are presented for three one-degree-of-freedom systems and a system with two-degrees-of-freedom. The approximate critical forcing amplitudes are plotted as a function of the forcing frequency, and the results are compared to those obtained by numerical integration of the equations of motion.
Probabilities of Escape, Re-Entry, and Orbit Decay Due to Misdirected Injection Maneuvers

Whenever a space vehicle is injected from low Earth orbit to high orbit or to escape, there is a small probability of misdirection. Once misdirection is assumed, then up to three major families of trajectories may result: escape, re-entry, or orbit decay. Analytic models of these trajectories provide contours on the injection sphere. Analytic integration of the areas between the contours gives the relative probability of each family occurring. The approximate analytic models are much faster in providing solutions than the numerical methods currently in use and have comparable accuracy. The new method provides a useful tool in the safety analysis of both single and multistage injection maneuvers. Recent applications have included analysis of the Galileo and the Ulysses injections into interplanetary trajectories.
Neuron-schwann cell interaction in basal lamina formation

Abstract The availability of tissue culture systems that allow the growth of nerve cells, Schwann cells, and fibroblasts separately or in various combinations now makes possible investigation of the role of cell interactions in the development of the peripheral nervous system. Using these systems it was earlier found that basal lamina is formed on the Schwann cell surface in cultures of sensory ganglion cells and Schwann cells without fibroblasts. It is here reported that the presence of nerve cells is required for the generation of basal lamina on the Schwann cell plasmalemma. Utilizing nerve cell-Schwann cell preparations devoid of fibroblasts, this was found in the following ways. (1) When nerve cells are removed from 3- to 5-week-old cultures, the basal lamina disappears from Schwann cells. (2) If nerve cells are added back to such Schwann cell populations, Schwann cell basal lamina reappears. (3) Removal of nerve cells from older (3–4 months) cultures does not lead to basal lamina loss; areas presumed not to have been coated with lamina before neurite degeneration remain so, suggesting that the lamina persists but is not reformed. (4) If basal lamina is removed with trypsin, it is reformed in neuron plus Schwann cell cultures but not in Schwann cell populations alone. Thus, the formation but not the persistence of Schwann cell basal lamina requires the presence of nerve cells.
Comments on “neutron spectral unfolding using the Monte Carlo method”

Abstract In this note a number of flaws in the article Neutron Spectral Unfolding Using the Monte Carlo Method are identified and discussed. The questions raised by the development of the proposed methodology are shown to be too fundamental to allow serious use of the technique presented.
Nosocomial infections on a primary nursing unit

Primary nursing care is a philosophy of patient care in which a primary nurse is responsible for all of the patients’ nursing needs. With this type of care, a single registered nurse coordinates all of the patient’s activities throughout the entire period of hospitalization. When the primary nurse is not on duty, the patient is cared for by “associate nurses.” It is generally thought that primary nursing care offers a “hands on” approach to nursing care. Some authorities believe that primary nursing increases the quality and consistency of care for the patient.‘, 2 On the other hand, the team-leading philosophy of nursing care is based on management principles wherein registered nurses oversee the care of patients in their unit and direct the activities of other registered nurses, licensed practical nurses, and aides. The team leader is the supervisor of ward activities and may also be responsible for dispensing medications. With this philosophy of nursing care, several different nurses and aides are responsible for the total care of an individual patient. Care is
Experimental determination of the cost of lesion healing on Porites compressa growth

The spotted puffer (Arothron meleagris) commonly feeds on finger coral (Porites compressa) on Hawaiian shallow reefs. The predation involves removal of branch tips, resulting in open lesions that, in the field, heal in little over a month. This study determined the cost of tissue regeneration across simulated bite scars on the growth of experimentally scarred P. compressa nubbins, of three different size classes (4, 2, 1 cm tall), in a controlled laboratory environment. The results indicate that inflicted P. compressa lesions heal completely within approximately 36 days, on even the smallest nubbins. While growth was slowed before lesions closed, the healing process did not appear to affect the longer-term growth of fragments. Successful regeneration of tissue may be explained by small lesion size, the high surface area to perimeter ratio of the lesions, and the location of lesions on the growing tips. The lack of impact on overall growth rate of experimental fragments indicates that under favorable conditions, P. compressa is resilient to predation.
India at the Crossroads: Battling the HIV/AIDS Pandemic

India already has the second‐largest number of people living with HIV/AIDS, a number that could reach a staggering 20–25 million by decade's end unless the country can harness its immense pool of scientists and scientific institutions, the pharmaceutical industry, and private businesses to tackle the pandemic.
Elizabeth Grosz. Becoming Undone: Darwinian Reflections on Life, Politics, and Art. Durham: Duke UP, 2011. viii + 264 pp.

Review of Elizabeth Grosz. Becoming Undone: Darwinian Reflections on Life, Politics, and Art. Durham: Duke UP, 2011. viii + 264 pp.
The Vocational Rehabilitation Counselor on Mental Patient Treatment Teams.

This study asked the question: What are the role expectancies of treatment personnel in the treatment community and are they consistent across patients' emotional condition? An 83-item inventory was developed and administered under three different sets of instructions, each characterizing a different patient condition. Treatment staff and administrators were asked to rate items on the basis of the level of expectancy they held for their team vocational rehabilitation counselor. The analyses suggest that treatment staff and counselors do not agree on role expectations and that patient condition is a significant mediating variable.
The modality and non-extensionality of the quantifiers

We shall try to defend two non-standard views that run counter to two well-entrenched familiar views. The standard views are (1) the universal and existential quantifiers of first-order logic are not modal operators, and (2) the quantifiers are extensional. If that is correct then the counterclaims create genuine problems for some traditional philosophical doctrines.
Lipid hydroperoxides evoke antigonadotropic and antisteroidogenic activity in rat luteal cells.

At functional luteolysis, the rat corpus luteum generates hydrogen peroxide (H2O2), which is known to rapidly inhibit gonadotropin-sensitive cAMP and progesterone production in isolated luteal cells. Lipid peroxides also increase markedly in the rat corpus luteum with the onset of functional luteolysis, and H2O2 is a potent inducer of lipid peroxidation. However, the actions of lipid peroxides on cell function are unknown. The objective of this study was to investigate the impact of typical lipid peroxides, cumene hydroperoxide (CuOOH) and 15(S)-hydroperoxyeicosatetraenoic acid, on rat luteal cells. CuOOH inhibited both LH-sensitive cAMP accumulation (ED50, 25 microM) and progesterone production (ED50, 20 microM). 15(S)-hydroperoxyeicosatetraenoic acid also dose dependently inhibited steroidogenesis. A significant reduction of LH-stimulated progesterone production was evident within 5 min of treatment with CuOOH, whereas inhibition of cAMP accumulation was not evident until 60 min. 8-Bromo-cAMP and 22-hyd...
Reduced chromium retention in patients with hemochromatosis, a possible basis of hemochromatotic diabetes.

Chromium (III) has recently been shown to be an essential trace mineral in rats, being required for normal function of insulin in controlling glucose metabolism. Chromium is transported in the body bound to transferrin, where it binds competitively with iron. Hemochromatosis is an iron storage disease in humans characterized by highly saturated transferrin levels and sometimes by diabetes. We postulated that the diabetes may be due to exclusion of chromium by iron at metabolic binding sites. 51Cr(III) was administered i.v. to 5 normal males, 6 patients with hemochromatosis prior to therapeutic removal of iron, and 5 patients with varying levels of iron loading. The retention of 51Cr was measured with a whole-body counter for 8 mo and blood levels were measured for 40--80 days. Analysis of the whole-body retention curves revealed 3 exponential components with T1/2s of .56 days, 12.7 days, and 192 days; the blood curves had 4 components with T1/2s of 13 min; 6.3 hr, 1.9 days, and 8.3 days. The T1/2s were not significantly different between the normals and patients. The coefficients of these components however, were significantly lower for the long T1/2 components in the iron-loaded patients, demonstrating reduced retention of 51Cr as postulated. Whether this reduced retention of chromium is causally related to diabetes in hemochromatosis and whether abnormal chromium metabolism is involved in endogenous diabetes, thus, becomes an important question for future study.
Black five-branes and fluxbranes on gravitational instantons

We apply a U-duality based solution-generating technique to construct supergravity solutions which describe nonextremal D5-branes and fluxbranes on various gravitational instantons. This includes an F7-brane wrapped on a sphere, which remains weakly coupled in the asymptotic region. We construct various superpositions of nonextremal D5-branes and fluxbranes that have angular momentum fixed by the parameters associated with their mass and two magnetic charges.
Humoral regulation of early hemopoiesis studied in culture

Hemopoietic proliferation appears to be controlled by a cascade of growth factors, each directed at a specific stage of development. In this model, proliferation of multipotential progenitors is regulated by such factors as interleukin (IL) 3, IL-4 and granulocyte-macrophage colony-stimulating factor (GM-CSF). Studies in our laboratory, however, indicated that IL-3 does not trigger cell cycling of dormant stem cells but rather supports proliferation of multipotential progenitors only after they exit from the dormant state. Subsequently, we identified several growth factors that appear to shorten the period of dormancy (G0) of early hemopoietic progenitors. These include IL-6, granulocyte (G) CSF, IL-11 and the ligand for c-kit. IL-11 was originally cloned from a primate stromal cell line, PU-34, and possesses multiple biological functions that are similar to IL-6. It works synergistically with IL-3 or IL-4 in support of proliferation of multipotential blast cell colonies. Stem cell factor (SCF) that was identified and cloned from buffalo rat liver cell line proved to be the ligand for c-kit. SCF enhances IL-3-dependent but not IL-4-dependent proliferation of early progenitors. SCF was also found to collaborate with IL-6 or G-CSF in support of proliferation of multipotential progenitors. These observations indicate the importance of stromal cells in regulating the very early process of stem cell proliferation.
Mean field theory of liquid crystalline phases of disc-shaped molecules

Abstract McMillan's model of smectic ordering is applied to systems of disc-like molecules. Self-consistent equations for the parameters characterizing orientational and two-dimensional hexagonal translational order are derived from an anisotropic model interaction; numerical solution yields the order parameters and entropy as functions of temperature and interaction range.
A review of the global relationship among freshwater fish, autotrophic activity, and regional climate

The relationship between autotrophic activity and freshwater fish populations is an important consideration for ecologists describing trophic structure in aquatic communities, fisheries managers tasked with increasing sustainable fisheries development, and fish farmers seeking to maximize production. Previous studies of the empirical relationships of autotrophic activity and freshwater fish yield have found positive relationships but were limited by small sample sizes, small geographic scopes, and the inability to compare patterns among many types of measurement techniques. Individual studies and reviews have also lacked consistent consideration of regional climate factors which may inform relationships between fisheries and autotrophic activity. We compiled data from over 700 freshwater systems worldwide and used meta-analysis and linear models to develop a comprehensive global synthesis between multiple metrics of autotrophic activity, fisheries, and climate indicators. Our results demonstrate that multiple metrics of fish (i.e., catch per unit effort, yield, and production) increase with autotrophic activity across a variety of fisheries. At the global scale additional variation in this positive relationship can be ascribed to regional climate differences (i.e., temperature and precipitation) across systems. Our results provide a method and proof-of-concept for assessing inland fisheries production at the global scale, where current estimates are highly uncertain, and may therefore inform the continued sustainable use of global inland fishery resources.
New methods in oblique slice generation

In this paper, we present a new approach to the generation and manipulation of oblique slices of MR/CT or any voxel space images. We consider the result of the voxel space as if it would be cut by a scalpel, simulating the action of a surgeon. With the intervention of a new definition of discrete 3D voxel plane, we show that this can be done in a highly efficient way and that there are very few computations to do. It is shown that the supercover of the continuous oblique plane is a 6-connected discrete plane that has many very interesting properties that can be usefully exploited. For instance, geometrical considerations avoid much of the intersection computations and once one oblique slice is generated, all the other parallel oblique slices can be generated with few further computations. These results are applied to improve the existing algorithms and provide some ideas for new ones. It should also improve the handling possibilities of oblique slices, indeed, almost all that can be done on a sagittal or axial slice can then also be done on oblique slices. An extension to 4D oblique slices is possible.
Measuring what medical students think about complementary and alternative medicine (CAM): a pilot study of the complementary and alternative medicine survey.

With increasing national and international support for the development of Complementary and Alternative Medicine (CAM) curricula in American medical schools, it is essential to measure what learners know and believe about CAM in order to assess outcomes of new teaching efforts. This paper describes the development and initial results of a survey designed for those purposes. The survey is constructed so that earlier single-institution studies of students’ attitudes toward CAM topics, preferred ways of learning about CAM, and students’ use of CAM therapies for self-care might be replicated and extended. A pilot test of the Complementary and Alternative Medicine ( CAM) Survey was conducted with third-year medical students at the University of Texas Medical Branch. Validity and reliability studies of the survey were conducted. Findings were compared to those of previously published studies. Interpretable subscales were constructed from survey questions. Students’ attitudes toward CAM-related topics were generally favorable. More students were familiar with biological-based therapies than with other CAM therapies. The majority of respondents listed lectures as their preferred way to learn about CAM. Respondents’ own CAM use varied; minority and economically-disadvantaged students were more likely to use CAM therapies than other students. The survey is a promising assessment of student attitudes toward and knowledge of CAM therapies.
Investigation of Laser Induced Structure formation and resultant fluorescence

Abstract The formation mechanism of 3D micron-sized fluorescent structures generated in silver nanoparticle containing sodium citrate dihydrate films, during exposure to focused laser radiation, was investigated. Microscopic and thermochemical data indicate that heat accumulates at the nanoparticle surface. The heat causes local melting and an increase in temperature beyond the decomposition point of the immediate surrounding layer. In turn this leads to the rapid release of volatile gases (H 2 O and CO 2 ). These expanding gases push the melted liquid pool outward, from the center of the focal volume, leaving behind a trough-like structure with elevated edges. It was observed that the edges of the structures were fluorescent. The fluorescence mechanism was investigated using atomic force, scanning electron and Confocal Fluorescence Microscopy. The observed fluorescence was attributed to the decomposition of sodium citrate dihydrate to sodium citrate. The presence of water acts to quench fluorescence in the bulk film, but near regions that experienced heat, the water is driven off.
Pancreatic carcinoma cells express neuropilins and vascular endothelial growth factor, but not vascular endothelial growth factor receptors

BACKGROUND Neuropilins (NRPs) are characterized as coreceptors of vascular endothelial growth factor (VEGF). In the current study, the authors assessed the expression of NRPs, VEGF, and vascular endothelial growth factor receptors (VEGFRs), as well as VEGF-induced cell proliferation, in pancreatic carcinoma cell lines and tissue specimens. METHODS Human pancreatic carcinoma cell lines (Panc-1 and MIA PaCa-2), normal human pancreatic ductal epithelial cells (HPDE), and human umbilical vein endothelial cells (HUVECs) were cultured. Human pancreatic adenocarcinoma tissue specimens were also studied. Expression levels of NRPs, VEGFRs, and VEGF were determined by real-time polymerase chain reaction analysis and immunostaining. Cell proliferation was examined using a [3H]thymidine incorporation assay. RESULTS Both NRP-1 and NRP-2 were expressed in Panc-1 cells, HPDE cells, and HUVECs but were expressed minimally in MIA PaCa-2 cells. Panc-1 expressed 30 times more NRP-1 mRNA than NRP-2 mRNA. NRP-1 levels in Panc-1 cells were 5.3 times higher than in HPDE cells but were similar to NRP-1 levels in HUVECs. NRP-2 levels in Panc-1 cells were similar to NRP-2 levels in HPDE cells but lower than NRP-2 levels in HUVECs. Expression of all three VEGFRs was observed only in HUVECs. However, VEGF mRNA was detected in all cell types except for HUVECs. NRP-1 immunoreactivity levels were much higher than NRP-2 immunoreactivity levels in Panc-1 and human pancreatic adenocarcinoma tissue specimens, whereas VEGFRs were not detected in either of these two settings. In response to VEGF165, [3H]thymidine incorporation in Panc-1 cells increased significantly (by 61%; P < 0.01). A monoclonal antibody against human NRP-1 significantly blocked VEGF-induced cell proliferation in Panc-1 cells. CONCLUSIONS The pancreatic carcinoma cell line Panc-1 and adenocarcinoma tissue specimens expressed high levels of NRP-1 and VEGF, but not VEGFRs, and exogenous VEGF significantly increased NRP-1-mediated, but not VEGFR-mediated, Panc-1 cell proliferation. These data suggested that NRP-1 may be involved in the pathogenesis of pancreatic carcinoma. Cancer 2004. © 2004 American Cancer Society.
Temperature, injection level, and frequency dependences of some extrinsic luminescence bands in ZnTe

Using cathodoluminescence measurements between 80 and 300 K, we have investigated the temperature, injection level, and frequency dependences of three extrinsic luminescence bands in nominally undoped ZnTe. At 80 K, our material shows strong edge emission and broad extrinsic bands near 1.59 eV and 2.08 eV. The peak position and band shape are independent of injection level for both these extrinsic bands. 80 K measurements of frequency response from 50 Hz to 50 MHz show that the 2.08 eV band has an exponential time decay with a time constant of 0.045 μsec. The 1.59 eV band shows a more complex frequency dependence which indicates that one component of the response has a time constant of 1.85 μsec. At temperatures above 80 K the 2.08 eV band quenches with an activation energy of 0.22 eV which indicates that the transition originates near a band edge. In contrast, the 1.59 eV band does not quench with a well-defined activation energy. The peak of the 2.08 eV band follows the temperature dependence of the edge emission energy, whereas the peak of the 1.59 eV band shows the opposite behavior. From the 80 K measurements, we conclude that the 2.08 eV band results from a conduction-band-to-acceptor transition, and that the 1.59 eV band results from an intracenter transition between localized levels of a compact complex. Above 160 K, a third extrinsic band begins to appear near 1.80 eV. This band becanes increasingly prominent with increasing temperature. The frequency dependence of the 1.80 eV band at 166 K indicates an exponential time decay with a time constant of 0.37 μsec. However, the frequency dependence changes with temperature and a faster component appears in the response at 300 K. We conclude that 1.80 eV band near 160 K results primarily from an intracenter transition in a compact complex, and that there is a contribution from free-to-bound transitions at 300 K.
Two-Way Laser Link over Interplanetary Distance

Here we report timed observations with subnanosecond precision of short laser pulses at a distance of nearly 24 million kilometers between the Mercury Laser Altimeter (MLA) aboard the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft and the NASA Goddard Geophysical and Astronomical Observatory (GGAO). Forty MLA downlink observations and 90 uplink observations were obtained during observing sessions on 27 and 31 May 2005. Precise standard ground timing allowed a solution for spacecraft range, range rate, and acceleration, as well as clock bias. This experiment established a new distance record for laser detection and accomplished a two-way laser link at an interplanetary distance.
Local stability properties of the modified Hamiltonian dynamic system

Abstract The local stability properties of stationary points of the modified Hamiltonian dynamic system are investigated. The modified Hamiltonian dynamic system characterizes the optimal state-costate trajectories of optimal control problems with discounting defined on an infinite horizon. It is shown that a Curvature Assumption, introduced by Rockafellar, is sufficient for an optimal steady-state to possess the saddlepoint property. The result is derived by matrix methods.
Resource discovery in ant communities: do food type and quantity matter?

1. Omnivorous woodland ant species trade off between the ability to find and behaviourally control food resources. Dominant species can limit the ability of subordinates to harvest certain food items. However, subordinate species, by being faster discoverers, could gain access to such food items by arriving at them first. 2. In this study, we tested the hypothesis that resource-directed discovery occurs in ant communities and that good discoverers preferentially discover high value resources. We did this by measuring time to discovery and the number of discoveries of high and low levels of two resource types, crickets and honey, for species occurring in Texas and Arizona woodland ant communities. 3. Ants discovered resources roughly 10 times faster in Texas than in Arizona. They discovered crickets more rapidly than honey in both communities, but there was no difference in the discovery of different resource levels. We also found that species were not biased in their discovery of different resource types or levels. 4. These results provide indirect evidence that discovery is directed by resource stimuli but that such directedness does not impact interspecific exploitative competition.
Toxoplasmosis in bone marrow transplant recipients

BONE MARROW TRANSPLANT RECIPIENTS are a t high risk for opportunistic infections. Toxoplasma gondii infection is a recognized complication in patients with a variety of immunodeficiency states, but has only been reported twice in bone marrow transplant recipients. In one of these, Toxoplasma serology was consistently negative and the diagnosis was made postmortem. 1 In the other, the diagnosis was based on a twofold increase in toxoplasma titers; however, the diagnosis was not substant ia ted on tissue biopsy. 2 We report toxoplasmosis in two bone marrow t ransp lan t recipients.
Crystal Structure of a Ternary Complex of Tritrichomonas foetus Inosine 5‘-Monophosphate Dehydrogenase: NAD+ Orients the Active Site Loop for Catalysis†,‡

Inosine 5‘-monophosphate dehydrogenase (IMPDH) catalyzes the conversion of IMP to XMP with the reduction of NAD+, which is the rate-limiting step in the biosynthesis of guanine nucleotides. IMPDH is a promising target for chemotherapy. Microbial IMPDHs differ from mammalian enzymes in their lower affinity for inhibitors such as mycophenolic acid (MPA) and thiazole-4-carboxamide adenine dinucleotide (TAD). Part of this resistance is determined by the coupling between nicotinamide and adenosine subsites in the NAD+ binding site that is postulated to involve an active site flap. To understand the structural basis of the drug selectivity, we solved the X-ray crystal structure of the catalytic core domain of Tritrichomonas foetus IMPDH in complex with IMP and β-methylene-TAD at 2.2 A resolution. Unlike previous structures of this enzyme, the active site loop is ordered in this complex, and the catalytic Cys319 is 3.6 A from IMP, in the same plane as the hypoxanthine ring. The active site loop forms hydrogen bo...
A Counterexample to a Conjecture of Scott and Suppes

In [1], it is conjectured that if S is a sentence in the first-order functional calculus with identity, and every subsystem of every finite relational system which satisfies S also satisfies S , then S is finitely equivalent to a universal sentence. (Two sentences are finitely equivalent if and only if they are satisfied by the same finite relational systems.) The following sentence S refutes that conjecture, and moreover S is satisfied by all finite subsystems of all (finite or infinite) relational systems which satisfy it. 1 S contains as predicate letters only the two-place predicate letters ≦, R (and the identity symbol =).
Mechanism for the Anti-Thyroid Action of Minocycline

Administration of minocycline (MN), a tetracycline antibiotic, produces a black pigment in the thyroids of humans and several species of experimental animals and antithyroid effects in rodents. We have previously shown that these effects appear to be related to interactions of MN with thyroid peroxidase (TPO), the key enzyme in thyroid hormone synthesis. In the present study, the mechanisms for inhibition of TPO-catalyzed iodination and coupling reactions by MN were investigated. MN was stable in the presence of TPO and H2O2, but adding iodide or a phenolic cosubstrate caused rapid conversion to several products. TPO-dependent product formation, characterized by on-line LC-APCI/MS and 1H-NMR, involved oxidative elimination to form the corresponding benzoquinone with subsequent dehydrogenation at the aliphatic 4-(dimethylamino) group. Addition of thiol-containing polymers (bovine serum albumin or thiol-agarose chromatographic beads) had a minimal effect on MN oxidation by TPO, but substantially reduced product formation and produced concomitant losses in free thiols. Covalent bonding through a thioether linkage of a reactive intermediate, the benzoquinone iminium ion, was inferred from these findings. Iodide- and phenolic cosubstrate-dependent oxidation of tetracycline to demethylated and dehydrogenated products was also observed, although at a slower rate than MN. The products and kinetics observed with MN were consistent with oxidation of MN by either the enzymatic iodinating species formed by reaction of TPO compound I with iodide or phenoxyl radicals/cations generated by TPO-mediated oxidation of a phenolic cosubstrate. The proposed reaction mechanism is consistent with alternate substrate inhibition of TPO-catalyzed iodination of tyrosyl residues in thyroglobulin (Tg) by MN, as previously reported. Furthermore, the observed phenoxyl radical-mediated oxidation of MN is consistent with its previously reported potent inhibition of the coupling of hormonogenic iodotyrosine residues in Tg in the reaction that forms thyroid hormones. The proposed reaction mechanism also implicates a reactive benzoquinone iminium ion intermediate that could be important in toxicity of MN.
A decomposition of multidimensional point sets with applications to k-nearest-neighbors and n-body potential fields

We define the notion of a well-separated pair decomposition of points in d-dimensional space. We then develop efficient sequential and parallel algorithms for computing such a decomposition. We apply the resulting decomposition to the efficient computation of k-nearest neighbors and n-body potential fields.
How versatile are inositol phosphate kinases

This review assesses the extent and the significance of catalytic versatility shown by several inositol phosphate kinases: the inositol phosphate multikinase, the reversible Ins(1,3,4) P (3)/Ins(3,4,5,6) P (4) kinase, and the kinases that synthesize diphosphoinositol polyphosphates. Particular emphasis is placed upon data that are relevant to the situation in vivo. It will be shown that catalytic promiscuity towards different inositol phosphates is not typically an evolutionary compromise, but instead is sometimes exploited to facilitate tight regulation of physiological processes. This multifunctionality can add to the complexity with which inositol signalling pathways interact. This review also assesses some proposed additional functions for the catalytic domains, including transcriptional regulation, protein kinase activity and control by molecular 'switching', all in the context of growing interest in 'moonlighting' (gene-sharing) proteins.
Steady State Crustal Spreading

Evidence which bears on the processes of continental drift, ocean floor spreading and the appearance of mid-oceanic rises is rapidly accumulating. The assumption that the mid-oceanic rises represent a steady state1,2 leads to estimates of the rate of ocean floor spreading and of subsidence which in turn suggest geophysical tests of the theory.
Comparing Language Use in the Writing of Developmental Generation 1.5, L1, and L2 Tertiary Students.

Developmental composition courses serve a sizable and growing number of Generation 1.5 students, or long-term U.S. resident language learners, and it is believed that language challenges may be part of Generation 1.5 writers’ difficulty in controlling the academic register. The current study investigates possible similarities and differences between Generation 1.5 students (n = 149) and two other student groups: mainstream first language (L1) writers (n = 203) and more traditional second language (L2) writers (n = 55), thus determining the extent to which language-use variables distinguish Generation 1.5 texts from those of their classmates. Results indicate significant differences between Generation 1.5 and L2 students on holistic writing quality, word errors, word class errors, verb errors, total identified errors, and spoken features of language. Generation 1.5 and L1 texts significantly differed on academic features of language. Implications are presented, suggesting that developmental Generation 1.5 ...
Avalanche-multiplication-region operation of n--p--n - --n + power transistors

Internal behaviour of an n-p-n−-n+ high-voltage power transistor for the avalanche-multiplication-region operating conditions is presented as obtained by a mathematical model. This model incorporates the avalanche generation of carriers due to electric field and current density and the resulting semiconductor transport equations are solved in two dimensions by numerical methods.
Towards the development of a bioartificial pancreas: Immunoisolation and NMR monitoring of mouse insulinomas

A promising method for diabetes treatment is the implantation of immunoisolated cells secreting insulin in response to glucose. Cell availability limits the application of this approach at a medically-relevant scale. We explore the use of transformed cells that can be grown to large homogeneous populations in developing artificial pancreatic tissues. We also investigate the use of NMR in evaluating, non-invasively, cellular bioenergetics in the tissue environment. The system employed in this study consisted of mouse insulinoma βTC3 cells entrapped in calcium alginate/poly-L-lysine (PPL)/alginate beads. The PPL layer imposed a molecular weight cutoff of approximately 60 kDa, allowing nutrients and insulin to diffuse through but excluding high molecular weight antibodies and cytotoxic cells of the host. We fabricated a radiofrequency coil that can be double-tuned to 1H and 31P, and an NMR-compatible perfusion bioreactor and support circuit that can maintain cells viable during prolonged studies. The bioreactor operated differentially, was macroscopically homogeneous and allowed the acquisition of 1H images and 31P NMR spectra in reasonable time intervals. Results indicated that entrapment had little effect on cell viability; that insulin secretion from beads was responsive to glucose; and that the bioenergetics of perfused, entrapped cells were not grossly different from those of cells never subjected to the immobilization procedure. These findings offer promise for developing an artificial pancreatic tissue for diabetes treatment based on continuous cell lines.
Pharmacodynamics of Plasma Nitrate/Nitrite as an Indication of Nitric Oxide Formation in Conscious Dogs

Background The present investigation was undertaken to better understand the production of nitric oxide (NO) in vivo as measured by alterations in plasma nitrite or nitrate in blood samples from studies in experimental animals or clinical studies in humans. Methods and Results Plasma samples were taken from the aorta, the coronary sinus, a peripheral vein in the leg (skeletal muscle), or the right ventricle (mixed venous) in chronically instrumented conscious dogs. Plasma nitrite was converted to NO gas in an argon environment by use of hydrochloric acid, and plasma nitrate was converted first to nitrite with nitrate reductase and then to NO gas with acid. Standard curves were constructed, and the amount of nitrite and nitrate in plasma was determined. The primary metabolite was nitrate, whereas nitrite was approximately 10% of the total and remained constant. In the resting dog, the only vascular bed with a positive arterial-venous nitrate difference, evidence for production of NO, was the heart. Nitrate...