cssi/SciSciGPT-SciSciNet huggingface dataset:
The metabolism of leucine by developing rat brain: effect of leucine and 2-oxo-4-methylvalerate on lipid synthesis from glucose and ketone bodies.

— The oxidation of l-[U-14C]leucine and l-[l-14C]leucine at varying concentrations from 0.1 to 5mM to CO2 and the incorporation into cerebral lipids and proteins by brain slices from 1-week old rats were markedly stimulated by glucose. Although the addition of S mM-dl-3-hydroxybutyrate had no effect on the metabolism of [U-14C]leucine by brain slices from suckling rats, the stimulatory effects of glucose on the metabolism of l-[U-14C]leucine were markedly reduced in the presence of dl-3-hydroxybutyrate. The stimulatory effect of glucose on leucine oxidation was, however, not observed in adult rat brain. Furthermore, the incorporation of leucine-carbon into cerebral lipids and proteins was also very low in the adult brain. The incorporation of l-[U-14C]leucine into cerebral lipids by cortex slices was higher during the first 2 postnatal weeks, which then declined to the adult level. During this time span, the oxidation of l-[U-14C]leucine to CO2 remained relatively unchanged. The incorporation in vivo of D-3-hydroxy[3-14C]butyrate into cerebral lipids was markedly decreased by acute hyperleucinemia induced by injecting leucine into 9-day old rats. In in vitro experiments, 5 mM-leucine had no effect on the oxidation of [U-14C]glucose to CO2 or its incorporation into lipids by brain slices from 1-week old rats. However, 5 mM-leucine inhibited the oxidation of d-3-hydroxy-[3-14C]butyrate, [3-14C]acetoacetate and [1-14C]acetate to CO2 by brain slices, but their incorporation into cerebral lipids was not affected by leucine. In contrast 2-oxo-4-methylvalerate, a deaminated metabolite of leucine, markedly inhibited both the oxidation to CO2 and the incorporation into lipids of labelled glucose, ketone bodies and acetate by cortex slices from 1-week old rats. These findings suggest that the reduction in the incorporation in vivo of d-3-hydroxy[3-14C]butyrate into cerebral lipids in rats injected with leucine is most likely caused by 2-oxo-4-methylvalerate formed from leucine. Since the concentrations of leucine and 2-oxo-4-methylvalerate in plasma of untreated patients with maple-syrup urine disease are markedly elevated, our findings are compatible with the possibility that an alteration in the metabolism of glucose and ketone bodies in the brain may contribute to the pathophysiology of this disease.
Proteolytic and lipolytic deficiency of the exocrine pancreas

A 4-year-old girl with a lifelong history of severe growth failure, psychomotor retardation, chronic anemia, and prolonged periods of hypoproteinemic edema is described. Recent studies have demonstrated a lack of pancreatic trypsin, chymotrypsin, carboxypeptidase, and lipase in the duodenal fluid. Normal amylase activity was found to be present in the duodenal aspirate. Balance studies have confirmed the proteolytic and lipolytic defect. The patient has responded well to a protein-hydrolysate diet with added pancreatin. The selective deficiency (proteolytic and lipolytic) observed in this patient appears to represent a previously unreported example of discordant pancreatic enzyme secretion. The relationship of this disorder to related disorders in discussed.
Linearity test for Brillouin scattering in reflection and transmission modes for intense acoustic flux

Abstract Brillouin scattering intensity provides a linear measure of acoustic intensity for thermal equilibrium phonon populations. We present here a linearity test for scattering from intense acoustic flux such as is generated in acoustoelectrically amplified domains in GaAs and CdS. The test depends on superposition of oppositely propagating domains and does not require independent calibration of acoustic intensity. Two separate light scattering mechanisms were tested, (a) the bulk phonon-induced surface ripple mechanism in reflection, and (b) the bulk elasto-optic mechanism in transmission.
Quantum error correction for various forms of noise

Quantum error correction will be an indispensable ingredient of large-scale quantum computations. Conventional quantum error correction codes (QECC) have been devised with an independent-error model in mind, but one may expect that the noise affecting a system of qubits will, in general, exhibit nonzero correlations in time, or space, or both. This talk will present a brief introduction to the principles of quantum error correction, followed by a discussion of the performance of conventional QECCs in the presence of correlated noise.
Aging Disaster: Mortality, Vulnerability, and Long-Term Recovery among Katrina Survivors

Data from this multiyear qualitative study of the effects of Hurricane Katrina and flooding in New Orleans suggest differences in how the elderly cope with disaster. At the time of the disaster, the elderly of New Orleans were at greater risk than other groups, and more elderly died than any other group during the storm and in the first year after. Those who did survive beyond the first year report coping with the long-term disaster aftermath better than the generation below them, experiencing heightened stresses, and feeling as if they are "aging" faster than they should. We offer insight on how we might define and characterize disasters, and illustrate that long-term catastrophes "age" in specific ways.
Nuclear saturation and the smoothness of nucleon-nucleon potentials

Abstract The two-nucleon and nuclear matter problems are solved by matrix inversion in momentum space. Direct matrix inversion of the Lippman-Schwinger and Brueckner equations is shown to be useful for general nuclear potentials including ones that are local, nonlocal, weak, strong, central, or noncentral. This flexibility is employed to study the relationship between nuclear saturation and the smoothness of the two-nucleon interaction. Five potentials are considered that give approximately equivalent phase shifts but differ in their smoothness. Two examples of smooth potentials with very weak nonlocal tensor terms are given. The potentials are classified according to their smoothness by calculating the wave function defect and the wound integral for each case. The binding energy of nuclear matter is calculated for each potential using the effective mass and angle-averaged Pauli operator approximations. A self-consistent hole spectrum and a free particle spectrum are used. A systematic dependence of saturation on the smoothness of the two-nucleon interaction is found. Only strong potentials with strong tensor terms yield correct saturation, whereas very smooth potentials produce overbinding and large equilibrium densities.
Effects of contaminants on the frequencies of allozymes in populations of the central stoneroller

Allele and genotype frequencies for allozymes of phosphoglucomutase (PGM) differed significantly between populations of the central stoneroller (Campostoma anomalum, Rafinesque) collected from sites above and below impact from industrial activities. The frequencies of the PGM‒A allele and PGM‒AA and PGM‒AB genotypes were significantly less in populations of stoneroller minnows collected from impacted sites than in populations upstream of impact. Stonerollers with these sensitive PGM genotypes and stonerollers with genotypes of malate dehydrogenase MDH‒BB were more sensitive to the toxic effects of copper sulfate than other genotypes under laboratory conditions. These results suggest that individuals with certain allozymes may be more sensitive to the toxic effects of environmental contaminants than those with other genotypes. Selection or elimination of individuals with sensitive genotypes by contaminants may result in a narrowing of genetic diversity in populations and thus increase the susceptibility of these populations to further stress. Electrophoretic determination of genetic structure in fishes appears to be sensitive to changes in water quality and may be a useful tool for monitoring the health of aquatic populations.
Richter's syndrome – update on biology and management

Introduction: Richter's syndrome (RS) refers to a histological transformation of chronic lymphocytic leukemia (CLL) into an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL) and rarely Hodgkin's lymphoma. Patients with RS can present with rapidly enlarging lymph nodes, worsening ‘B’ symptoms, progressive organomegaly and elevated serum lactate dehydrogenase, erythrocyte sedimentation rate and β2-microglobulin levels. Recently, it was demonstrated that RS has molecular and cytogenetic characteristics distinct from de novo DLBCL and untransformed CLL. Some of the predisposing factors for RS include use of prior multiple chemotherapies for CLL, the presence of CDKN2A, TP53 mutations, NOTCH1 mutations, c-MYC abnormalities, unmutated immunoglobulin heavy chain, non-del13q cytogenetics, CD38 gene polymorphisms, stereotypy of subset 8 of B-cell receptor (BCR) and VH 4 – 39 gene usage. Patients with RS have a poor prognosis (median survival 1 – 2 years). These patients achieve short lasting...
Biological availability of nickel arsenides: cellular response to soluble Ni5As2.

Particulate Ni5As2 has been shown to be highly cytotoxic and carcinogenic. By measuring the solubility of Ni5As2 particles in a variety of aqueous solutions, we have determined that particulate Ni5As2 that might be produced during oil-shale retorting could be mobilized to the environment and made available to the cells of living organisms, including humans. Ni5As2 was five times more soluble in ground water taken from aquifers surrounding a major oil-shale source in Colorado, U.S.A., than in distilled water. It was also two times more soluble in oil-shale product water from an above-ground retort than in distilled water. Thus, it is possible that Ni5As2 could be solubilized and mobilized to the environment by the flooding of abandoned in situ retorts with ground water or by the disposal of oil-shale product water by spraying it on spent shale beds. Particulate Ni5As2 was found to be 12 times more soluble in culture growth medium than in distilled water, and much more soluble in solutions of amino acids, inorganic salts, organic constituents of culture medium, and 15% calf serum. These observations suggest Ni5As2 particles in airborne dust would be dissolved when they came in contact with the biological fluids of the lung and gastrointestinal tract. The availability to cells of the soluble products of Ni5As2 was demonstrated by measuring its effects on cell proliferation. As little as 1 ppm soluble Ni5As2 retarded Chinese hamster (CHO) cell proliferation in culture, and 4 ppm resulted in cell death. Flow cytometry measurements indicated there was a preferential cytotoxic effect on S-phase cells. Despite this, many cells survived to form colonies, causing concern that Ni5As2 might cause genetic damage that could be passed on to future cell generations. This did not appear to be the case, however, for no mutations could be detected at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus in cells that survived the cytotoxic effects. This suggests that Ni5As2 carcinogenesis might be caused by epigenetic rather than mutagenic mechanisms.
Prospective study of grapefruit intake and risk of breast cancer in postmenopausal women: the Multiethnic Cohort Study

In vitro and in vivo studies have shown that cytochrome P450 3A4 (CYP3A4) is involved in the metabolism of oestrogens. There is evidence that grapefruit, an inhibitor of CYP3A4, increases plasma oestrogen concentrations. Since it is well established that oestrogen is associated with breast cancer risk, it is plausible that regular intake of grapefruit would increase a woman's risk of breast cancer. We investigated the association of grapefruit intake with breast cancer risk in the Hawaii–Los Angeles Multiethnic Cohort Study, a prospective cohort that includes over 50 000 postmenopausal women from five racial/ethnic groups. A total of 1657 incident breast cancer cases were available for analysis. Grapefruit intake was significantly associated with an increased risk of breast cancer (relative risk=1.30, 95% confidence interval 1.06–1.58) for subjects in the highest category of intake, that is, one-quarter grapefruit or more per day, compared to non-consumers (Ptrend=0.015). An increased risk of similar magnitude was seen in users of oestrogen therapy, users of oestrogen+progestin therapy, and among never users of hormone therapy. Grapefruit intake may increase the risk of breast cancer among postmenopausal women.
A novel inspection and annealing procedure to rejuvenate phase change memory from cycling-induced degradations for storage class memory applications

A novel Cycle Alarm Point (CAP) inspection is proposed to monitor PCM cycling degradation. The degradation appears in two stages - (1) right shift of R-I during moderate cycling degradation, and (2) left shift of R-I when cycling damage is severe. We further propose an In-Situ-Self-Anneal (ISSA) procedure, such that once a CAP signal is detected, the annealing procedure is issued to rejuvenate the cells. We demonstrate, for the first time, PCM cycling degradation can be recovered repeatedly. This opens a new window to extend PCM endurance and reliability for storage class memory (SCM) applications.
Simultaneous detection and functional response of testosterone and estradiol receptors in osteoblast plasma membranes.

Osteoblasts derived from the periosteal surfaces of two–three-week-old male broiler chicken tibias were cultured for eight days. The cells were then loaded with fura-2/AM ester to detect surges in intracellular Ca2+. Treatment with 10−7 M testosterone (T) or 17β-estradiol (E) elicited a rapid (within seconds) response that was substantially reduced by introducing the calcium chelating agent EGTA or the calcium-channel blocker verapamil. The hormones were equally effective when covalently linked to bovine serum albumin (BSA), a procedure that ensures the hormone does not enter the cells. The rapid response to surface-bound steroids indicates that the responses were invoked through plasma-membrane receptors. The source of Ca2+ was shown to be through entry from external sources, as well as from intracellular stores. Flow cytometry of fluorescein-tagged T-BSA and E-BSA revealed that osteoblasts derived from male chickens had similar and substantial levels of both receptors. J. Cell. Biochem. 79:620–627, 2000. © 2000 Wiley-Liss, Inc.
Real-time integrated model for visual perception and fuzzy control

Abstract Current state-of-the-art security systems incorporate ‘passive’ and/or ‘human’ elements, the effectiveness of which can only be measured by their ability to ‘deter’ intruders. However, rapidly changing economic and cultural conditions have weakened the strengths associated with such systems. In the not too distant future, the need for an ‘active’ security system will become necessary in order to reduce the onslaught of crime. This paper presents a conceptual basis for the incorporation of artificial intelligence concepts in the design and implementation of ‘active’ security systems. Specifically, the paper discusses issues pertaining to a real-time model for visual perception and tracking of possible intruders.
Wear of Fluorapatite Single Crystals: I. A Method for Quantitative Evaluation of Wear

A quantitative method for characterizing the surface failure of nonmetallic single crystals under sliding was evaluated. It was found that strain rate, load, and slider design influenced the wear of natural fluorapatite single crystals. High loads and slider designs with small radiuses and sharp angles resulted in the deepest penetration.
Performance evaluation of CDMA, WDMA, DWDMA networks

The demand for bandwidth for applications in high-speed networks requires improved network topologies, throughput, and parallelism. Many techniques such as optical code-division multiple access (CDMA), wavelength division multiple access (WDMA) and dense WDMA (DWDMA), have shown considerable potential for high-speed network applications. This paper evaluates the performance of these techniques with respect to bandwidth utilization and delay under various scenarios. Simulation results showed that optical CDMA system emerges as the most efficient system because CDMA utilization is the highest when compared to the WDMA and DWDMA systems, and that CDMA is better for high offered loads compared to WDMA and DWDMA.
PHOTONIC-BAND-STRUCTURE CALCULATION OF MATERIAL POSSESSING KERR NONLINEARITY

The Finite Difference Time Domain (FDTD) technique dates back to 1966 when it was first developed by Yee [1]. Since then it has been widely used to calculate the radar cross section of objects as well as normal modes of wave guides. Chan et al. [2] recently applied this technique to calculate the band structure of photonic crystal with excellent results. The motivation for their use of this technique is the fact this technique scales linearly with system size. Systems having random defects, which destroy any periodicity, are often studied using the “super cell” method where the system is assumed to be periodic with a very large period. In such a case, it is important the technique for band structure calculation scales favorably with system size. The plane wave expansion technique, for example, is impractical since it scales as N3 where N is the system size. In this paper I show how the FDTD technique can be extended to calculate the band structure of nonlinear photonic crystals, in particular, those which possess Kerr nonlinearity.
Retrograde Metamorphism of Amphibolite, Bighorn Mountains, Wyoming

Twenty well-defined zones of schistose rocks occur within a thick amphibolite body in the southern Bighorn Mountains, Wyoming. The zones are 2 to 12 m thick and as much as 300 m long. Many of the zones are parallel to the strike of the amphibolite body. However, a significant number are oriented across its trend and at an angle to the strike of its foliation. Locally, the strike of amphibolite foliation is deflected near the schist zones, and blocks of amphibolite occur isolated within one of the zones. Adjacent to the schist, the amphibolite is typically a massive or layered, granoblastic aggregate of hornblende, andesine, some quartz, and minor accessories. The schist bodies consist of tremolite or magnesian actinolite, chlorite, talc, and local soclic oligoclase. Chemical analyses of schist and adjacent amphibolite indicate that the schist contains smaller amounts of TiO 2 , A1 2 O 3 , CaO, Na 2 O, K 2 O, and greater amounts of MgO and H 2 O. Representing greenschist facies conditions, the schist formed by local retrograde metamorphism along shear zones superimposed on the amphibolite, which itself evolved during amphibolite-facies regional metamorphism. Retrograde metamorphism was facilitated by means of shearing stress and magnesium-rich aqueous fluids.
Parallel Pipelined Fractal Image Compression using Quadtree Recomposition

In this paper we present a model and experimental results for performing parallel fractal image compression using circulating pipeline computation and employing a new quadtree recomposition approach. A circular linear array of processors is employed and utilized in a pipelined fashion. In this approach, a modification of the scheme given by Jackson and Blom, quadtree sub-blocks of an image are iteratively recombined into larger blocks for fractal coding. For complex images, this approach exhibits superior parallel runtime performance when compared to a classical quadtree decomposition scheme for fractal image compression, while maintaining high fidelity for reconstructed images. Quantitative results include parallel runtime comparisons with the decomposition approach for several images of varying complexity, an evaluation of attained compression ratios and SNR for reconstructed images. Experimental results using an nCUBE-2 supercomputer are presented.
Classification of Material Surfaces Using the Polarization of Specular Highlights

Recently there has been interest, in computer vision research, in the segmentation of images based upon the actual material makeup of the objects or object parts that constitute image regions. The idea is to identify image characteristics which can be used to predict the material properties of objects that are being imaged. A majority of object surfaces can be simply classified according to their basic electrical properties; metal objects (e.g. Aluminum, Copper) conduct electricity rather well while dielectric objects (e.g. Rubber, Plastic, Ceramic) conduct electricity poorly. Distinguishing image regions according to whether they correspond to metal or dielectric material can provide important information for scene understanding especially in industrial machine vision. One such major application is circuit board inspection where the presence of dielectric or metal material in the wrong place can cause trouble. A previous approach to the problem of identifying metal or dielectric material in images is based upon careful spectral (i.e. color) analysis of reflected light from material objects. This paper presents a technique for identifying the material properties of objects in an image using a polarizing lens (i.e. Polaroid filter). Two images of the same scene are taken with a polarizing lens placed in front of a camera in two different respective orientations. Effectively these two images represent two linearly independent polarization components of the reflected light. It is shown that when the linearly independent components of polarization are taken parallel and perpendicular with respect to the plane in which specular rays travel that dielectric objects can be distinguished from metallic objects when specular highlights are present. In particular the two polarization components are very similar at specular highlights on metals while the two polarization components for specular highlights on dielectrics are very different, the perpendicular component having much larger magnitude than the parallel component. This is shown to hold regardless of whether the surface is polished or rough. Results for coated surfaces will be presented at a future date.
Influenza virus samples, international law, and global health diplomacy.

Indonesia’s decision to withhold samples of avian influenza virus A (H5N1) from the World Health Organization for much of 2007 caused a crisis in global health. The World Health Assembly produced a resolution to try to address the crisis at its May 2007 meeting. I examine how the parties to this controversy used international law in framing and negotiating the dispute. Specifically, I analyze Indonesia’s use of the international legal principle of sovereignty and its appeal to rules on the protection of biological and genetic resources found in the Convention on Biological Diversity. In addition, I consider how the International Health Regulations 2005 applied to the controversy. The incident involving Indonesia’s actions with virus samples illustrates both the importance and the limitations of international law in global health diplomacy.
Finely Tuned Regulation of the Aromatic Amine Degradation Pathway in Escherichia coli

FeaR is an AraC family regulator that activates transcription of the tynA and feaB genes in Escherichia coli. TynA is a periplasmic topaquinone- and copper-containing amine oxidase, and FeaB is a cytosolic NAD-linked aldehyde dehydrogenase. Phenylethylamine, tyramine, and dopamine are oxidized by TynA to the corresponding aldehydes, releasing one equivalent of H2O2 and NH3. The aldehydes can be oxidized to carboxylic acids by FeaB, and (in the case of phenylacetate) can be further degraded to enter central metabolism. Thus, phenylethylamine can be used as a carbon and nitrogen source, while tyramine and dopamine can be used only as sources of nitrogen. Using genetic, biochemical and computational approaches, we show that the FeaR binding site is a TGNCA-N8-AAA motif that occurs in 2 copies in the tynA and feaB promoters. We show that the coactivator for FeaR is the product rather than the substrate of the TynA reaction. The feaR gene is upregulated by carbon or nitrogen limitation, which we propose reflects regulation of feaR by the cyclic AMP receptor protein (CRP) and the nitrogen assimilation control protein (NAC), respectively. In carbon-limited cells grown in the presence of a TynA substrate, tynA and feaB are induced, whereas in nitrogen-limited cells, only the tynA promoter is induced. We propose that tynA and feaB expression is finely tuned to provide the FeaB activity that is required for carbon source utilization and the TynA activity required for nitrogen and carbon source utilization.
The tax base in transition: The case of Bulgaria

(1994). The tax base in transition: The case of Bulgaria. Communist Economies and Economic Transformation: Vol. 6, No. 4, pp. 537-552.
Influence of slitted polyethylene mulch, nitrogen rates, and trickle irrigation on potatoes

In 1974, potatoes(Solanum tuberosum L.) were grown on unmulched, clear, and black slitted polyethylene. Production and tuber specific gravity of the potatoes were determined at four nitrogen rates (0, 75, 150 and 225 lb/A) and with two varieties (Superior and Katahdin). In 1975, potatoes were grown on unmulched and clear slitted polyethylene with and without trickle irrigation. Nitrogen increased marketable yields up to 150 lb/A on the unmulched potatoes. Irrigation increased the marketable yields of potatoes on both unmulched and mulched plots. However, no advantage was found in marketable yields, specific gravities or tuber sizes of the potatoes grown on either clear or black slitted polyethylene mulch over conventional unmulched soil for the ‘Superior’ or ‘Katahdin’ varieties.
Hormone action at the membrane level. II. The binding of epinephrine and glucagon to the rat liver plasma membrane

Abstract The binding of epinephrine and glucagon to isolated rat liver membranes show s that both hormones have a much higher affinity for the plasma membrane than for the other cell membranes (nuclear, mitochondrial, endoplasmic reticulum). The binding of glucagon to the plasma membrane is more rapid than the binding of epinephrine. Propanolol, a β-andrenergic blocking agent, inhibits the binding of epinephrine to the plasma membrane. A study of several epinephrine analogs shows that the two ring hydroxyl groups are important in the binding of epinephrine to the membrane. p- Chloromercuribenzoate (PCMB) and 5',5-dithio-bis-2-nitrobenzoic acid (DTNB) both inhibit epinephrine binding and glucagon binding thus implicating SH groups on the receptor proteins. Heating membranes for 1 min at 100° does not appreciably affect the hormone binding but nearly completely inactivates the adenyl cyclase. Heating for 5 min at 100° abolishes the hormone binding. These results show that the hormone receptor proteins are separate from the adenyl cyclase. Extraction of membrane bound epinephrine with chloroform-methanol removes approx. 20–25% of the bound hormone, a finding which indicates at least two types of membrane bound epinephrine. The membrane bound glucagon and epinephrine were isolated by column chromagtography on Sephadex G-200. The receptor proteins were eluted just ahead of the void volume and were separated from the major adenyl cyclase activity. A second peak containing adenyl cyclase activity was eluted from the column with the void volume.
Induction of Enterococcal L-Forms by the Action of Lysozyme

Suspensions of enterococci were treated with lysozyme in the presence of osmotic stabilizers. The resulting osmotically fragile bodies prepared from Streptococcus faecium strain F24 and S. faecalis strain E1 gave rise to L-forms under optimal osmotic and nutritional conditions for treatment and subsequent growth. The most critical component of the growth medium, to obtain maximum yields, was the nature and concentration of the added salt. The two most effective salts were sodium chloride and ammonium chloride in the range of 2 to 3% (w/v) added to a suitable agar base. Ammonium chloride was more versatile, because it could be used with either sucrose or polyethylene glycol 4000 as the osmotic stabilizer for preparation and dilution of the osmotically fragile bodies. Sodium chloride would not consistently support growth of S. faecium F24 as L-forms when polyethylene glycol 4000 was used as the osmotic stabilizer during lysozyme treatment. Time-course studies of concurrent cell wall removal and L-form induction suggested that maximal induction required only cell wall damage rather than complete wall removal. This method for induction of L-forms from a suspension of enterococci is a significant improvement over other presently known methods.
BIRDSONG AND HUMAN SPEECH: Common Themes and Mechanisms

Human speech and birdsong have numerous parallels. Both humans and songbirds learn their complex vocalizations early in life, exhibiting a strong dependence on hearing the adults they will imitate, as well as themselves as they practice, and a waning of this dependence as they mature. Innate predispositions for perceiving and learning the correct sounds exist in both groups, although more evidence of innate descriptions of species-specific signals exists in songbirds, where numerous species of vocal learners have been compared. Humans also share with songbirds an early phase of learning that is primarily perceptual, which then serves to guide later vocal production. Both humans and songbirds have evolved a complex hierarchy of specialized forebrain areas in which motor and auditory centers interact closely, and which control the lower vocal motor areas also found in nonlearners. In both these vocal learners, however, how auditory feedback of self is processed in these brain areas is surprisingly unclear. Finally, humans and songbirds have similar critical periods for vocal learning, with a much greater ability to learn early in life. In both groups, the capacity for late vocal learning may be decreased by the act of learning itself, as well as by biological factors such as the hormones of puberty. Although some features of birdsong and speech are clearly not analogous, such as the capacity of language for meaning, abstraction, and flexible associations, there are striking similarities in how sensory experience is internalized and used to shape vocal outputs, and how learning is enhanced during a critical period of development. Similar neural mechanisms may therefore be involved.
A Probability Distribution and its Uses in Fitting Data

A four-parameter probability distribution, which includes a wide variety of curve shapes, is presented. Because of the flexibility, generality, and simplicity of the distribution, it is useful in the representation of data when the underlying model is unknown. A table based on the first four moments, which simplifies parameter estimation, is given. Further important applications of the distribution include the modeling and subsequent generation of random variates for simulation studies and Monte Carlo sampling studies of the robustness of statistical procedures.
Alkaline Hydrolysis of Titanium Dioxide Delustered Poly(ethylene Terephthalate) Yarns 1

Polyester yams containing four levels of TiO2 delusterant were hydrolyzed with NaOH and examined for physical and morphological changes. All four yarn types showed progressive weight loss with increasing time of hydrolysis. There was a loss in tenacity after six hours, but there were no changes in crystallinity. Surface morphology differed between the yams with and without delusterant after NaOH treatment. Hy drolyzed, delustered yams developed large, axially oriented pits along the fiber surfaces, while such pitting was absent on hydrolyzed yams containing no delusterant. The pitting originated where delusterant particles were embedded in the polymer matrix. Pits may develop in this location by preferential degradation of the less ordered polymer around the particles. With longer treatment time, the pits enlarged in size and, on fibers with high delusterant concentration, merged with adjacent pits, radically altering the surface topology of the fibers.
Differential ICP responses elicited by electrical stimulation of medial preoptic area.

Recent findings indicate a complex role for the medial preoptic area (MPOA) in modulating penile erection. To further investigate this important area we measured changes in intracavernous pressure ...
Structural insights and functional implications of choline acetyltransferase

The biosynthetic enzyme for the neurotransmitter acetylcholine, choline acetyltransferase (ChAT) (E.C. 2.3.1.6), is essential for the development and neuronal activities of cholinergic systems involved in many fundamental brain functions. ChAT catalyzes the transfer of an acetyl group from acetyl-coenzyme A to choline to form the neurotransmitter acetylcholine. Since its discovery more than 60 years ago much research has been devoted to the kinetic studies of this enzyme. For the first time we report the crystal structure of rat ChAT (rChAT) to 1.55 A resolution. The structure of rChAT is a monomer and consists of two domains with an interfacial active site tunnel. This structure, with the modeled substrate binding, provides critical insights into the molecular basis for the production of acetylcholine and may further our understanding of disease causing mutations.
1H Nuclear Magnetic Resonance (NMR) Metabolomic Study of Chronic Organophosphate Exposure in Rats

1H NMR spectroscopy and chemometric analysis were used to characterize rat urine obtained after chronic exposure to either tributyl phosphate (TBP) or triphenyl phosphate (TPP). In this study, the daily dose exposure was 1.5 mg/kg body weight for TBP, or 2.0 mg/kg body weight for TPP, administered over a 15-week period. Orthogonal signal correction (OSC) -filtered partial least square discriminant analysis (OSC-PLSDA) was used to predict and classify exposure to these organophosphates. During the development of the model, the classification error was evaluated as a function of the number of latent variables. NMR spectral regions and corresponding metabolites important for determination of exposure type were identified using variable importance in projection (VIP) coefficients obtained from the OSC-PLSDA analysis. As expected, the model for classification of chronic (1.5–2.0 mg/kg body weight daily) TBP or TPP exposure was not as strong as the previously reported model developed for identifying acute (15–20 mg/kg body weight) exposure. The set of majorly impacted metabolites identified for chronic TBP or TPP exposure was slightly different than those metabolites previously identified for acute exposure. These metabolites were then mapped to different metabolite pathways and ranked, allowing the metabolic response to chronic organophosphate exposure to be addressed.
Thermal Conductivity Measurements of Ultra-Thin Single Crystal Silicon Layers

Self-heating in deep submicron transistors (e.g., silicon-on-insulator and strained-Si) and thermal engineering of many nanoscale devices such as nanocalorimeters and high-density thermomechanical data storage are strongly influenced by thermal conduction in ultra-thin silicon layers. The lateral thermal conductivity of single-crystal silicon layers of thicknesses 20 and 100 nm at temperatures between 30 and 450 K are measured using joule heating and electrical-resistance thermometry in suspended microfabricated structures. In general, a large reduction in thermal conductivity resulting from phonon-boundary scattering is observed. Thermal conductivity of the 20 nm thick silicon layer at room temperature is nearly 22 W m -1 K -1 , compared to the bulk value, 148 W m -1 K -1 . The predictions of the classical thermal conductivity theory that accounts for the reduced phonon mean free paths based on a solution of the Boltzmann transport equation along a layer agrees well with the experimental results.
Sound source segregation in grey treefrogs: spatial release from masking by the sound of a chorus

Animals that communicate acoustically in noisy social environments face the problem of perceptually segregating behaviourally relevant signals from background noise. Studies of humans indicate improvements in speech perception tasks when target speech and a masking noise with the frequency spectrum of speech come from different locations. Thus for humans, spatial release from masking is an important mechanism of sound source segregation that functions in acoustic communication in noisy, real-world environments. Little previous work has investigated the mechanisms of sound source segregation in nonhuman animals that rely on acoustic signalling. I investigated spatial release from masking in the grey treefrog, Hyla chrysoscelis . Grey treefrogs form large breeding aggregations in which males produce loud advertisement calls that are necessary and sufficient for species recognition, source localization and selective mate choice by females. I tested the hypothesis that females would experience a release from masking when a synthetic advertisement call (target signal) and an artificial noise with the spectrum of a grey treefrog chorus (masker) were spatially separated. Using a phonotaxis paradigm, I assessed females' responses to the target signal at four signal-to-noise ratios (SNR) and two angular separations. Female responsiveness to the target signal increased as the SNR increased from −12 dB to +6 dB. More important, phonotaxis responses were faster at a 90° angle of signal–masker separation compared to one of just 7.5°. These results support the hypothesis that spatial release from masking is a potentially important mechanism for sound source segregation in animal acoustic communication.
New formulations for quantitative feedback theory

New formulations are presented for quantitative feedback theory that do not require the direct manipulation of templates in the classical sense. This enables the explicit incorporation of high-frequency unstructured uncertainty into the problem statement, and allows for constructive existence conditions for the solvability of the QFT problem. Necessary and sufficient conditions for robust stability and robust performance are presented for plants with both parametric and high-frequency unstructured uncertainty, that parallel their corresponding H∞ counterparts. This work extends the recent contribution of Jayasuriya and Zhao to plants with more general non-minimum phase characteristics such as RHP poles and zeros and time delays.
Differential Diagnosis of Kleine-Levin Syndrome

Investigators at Pitie-Salpetriere and Robert Debre Hospitals, and other centers in France, evaluated consecutive patients referred for suspected Kleine-Levin (KLS) syndrome, detailed differential diagnoses, and examined characteristics of patients with prolonged (>30 days) episodes.
Highly accelerated real-time cardiac cine MRI using k–t SPARSE-SENSE

For patients with impaired breath-hold capacity and/or arrhythmias, real-time cine MRI may be more clinically useful than breath-hold cine MRI. However, commercially available real-time cine MRI methods using parallel imaging typically yield relatively poor spatio-temporal resolution due to their low image acquisition speed. We sought to achieve relatively high spatial resolution (∼2.5 × 2.5 mm(2)) and temporal resolution (∼40 ms), to produce high-quality real-time cine MR images that could be applied clinically for wall motion assessment and measurement of left ventricular function. In this work, we present an eightfold accelerated real-time cardiac cine MRI pulse sequence using a combination of compressed sensing and parallel imaging (k-t SPARSE-SENSE). Compared with reference, breath-hold cine MRI, our eightfold accelerated real-time cine MRI produced significantly worse qualitative grades (1-5 scale), but its image quality and temporal fidelity scores were above 3.0 (adequate) and artifacts and noise scores were below 3.0 (moderate), suggesting that acceptable diagnostic image quality can be achieved. Additionally, both eightfold accelerated real-time cine and breath-hold cine MRI yielded comparable left ventricular function measurements, with coefficient of variation <10% for left ventricular volumes. Our proposed eightfold accelerated real-time cine MRI with k-t SPARSE-SENSE is a promising modality for rapid imaging of myocardial function.
A clinical, evidence-based approach to infectious causes of infertility in beef cattle

Infertility is the diminished or absent capacity to produce viable offspring. Infections that reduce ovulation rates, fertilization rates, embryonic survival rates, fetal survival rates or perinatal survival rates result in observed infertility in beef cows. Reproductive pathogens include Leptospira, Campylobacter, Hemophilus, Brucella, bovine herpesvirus-1, bovine viral diarrhea virus, Tritrichomonas foetus, and Neospora caninum. Infectious infertility can be prevented or controlled with appropriate surveillance, biosecurity, and/or vaccination. The objective of this review is to briefly summarize current scientific information to assist with adoption of surveillance methods, implementation of biosecurity and selection of appropriate commercially available vaccines.
Lost node recovery in a city-wide wireless sensor network using adaptive preselect filtering

In this paper, we describe our efforts to combat lost nodes in wireless sensor networks. Often times, the wireless sensor network is limited by interference. Specifically, in a practical setting it was found that lost nodes were caused by location of the sensor nodes in relative proximity to cellular broadcasting stations. This effect was modeled and combated using adaptable front end filtering to show the impact of an intelligent front end system as opposed to the more traditional static preselect filtering commonly applied. Using real system parameters, greater than 10% improvement in the packet reception rate compared to a static filter was achieved by adjusting the filtering to the surrounding environment. Only slight tuning was needed to be able to achieve the result and this indicates the traditional method of using a static preselect filter is suboptimal.
Layer-by-Layer Assembly of Thin Film Zener Diodes from Conducting Polymers and CdSe Nanoparticles

Ultrathin films have been prepared by self-assembling trioctylphosphine oxide, TOPO, capped n-type 20-40 A diameter CdSe nanoparticles and 1,6-hexadecanethiol, HDT, onto p-doped semiconducting polymers, chemically deposited poly(3-methylthiophene), PMeT (for DeWice A), and electrochemically deposited poly- (pyrrole), Ppy (for DeWice B). The semiconducting polymers have, in turn, been electrochemically layered (for DeWice A) or layer-by-layer chemically assembled (for DeWice B) onto derivatized conducting substrates. The ultrathin films have been characterized by absorption and emission spectroscopy, transmission electron microscopy, scanning force microscopy, X-ray photoelectron spectroscopy, and by electrochemical measure- ments. By controlling the level of doping into the p-type junction, it was possible to prepare dissymmetrical junctions and observe a rectifying behavior in the forward direction and a Zener breakdown in the reverse direction for Au/PMeT/(HDT/CdSe)3, DeWice A, and for Au/MEA/Ppy/(HDT/CdSe)3, DeWice B. Additionally, Au/MeA/PAH/CdSe (PAH ) poly(allylamine hydrochloride)), Au/MEA/Ppy/PSS/CdSe (PSS ) polystyrene sulfonate), and Au/MEA/Ppy/R-ZrP/CdSe (R-ZrP )R zirconium phosphate) films have been prepared and characterized.
Private Higher Education in Ethiopia: The Current Landscape

with doctoral programs in other countries to conduct research on some global issues and problems. 6. They encourage multiple flows in research collaboration between economically advanced and poorer countries with limited research resources or infrastructure. 7. They reintroduce foreign-language requirements, especially in English-speaking countries. The lack of foreign-language requirements for Ph.D. education has had negative consequences: much is lost by not being able to communicate directly with colleagues and collaborators, and communicating solely in English grants privileges to some students and puts others at a disadvantage. 8. Future-oriented programs initiate an approach that revives an awareness and commitment to civic engagement and world citizenship. World citizenship includes the notion of a citizen who crosses national boundaries without seeking to assimilate and to conform but instead accepts differences and embraces diversity. In preparing for a knowledge-based society, higher education systems will need to be modified. We recommend programs that focus on creating opportunities for doctoral students to become global citizens who not only can operate within a small sphere of elite intellectuals but also “move beyond critical public intellectuals to world citizens whose collective knowledge and actions presuppose visions of public life, community and moral accountability” (Henry Giroux). To put into operation and implement these changes will be our task for the future.
Learning to think by learning LOGO: Rule learning in third-grade computer programmers

Gains in logical thinking are assumed to result from learning computer programming. Although such assumptions are commonly held, there is little empirical work on cognitive changes resulting from computer programming. The present study reports results of 15 third-grade students at a private school in Dallas who learned LOGO during the school year. One-third of the students were given 1 h/week of individual computer time (separate from in-class instruction), and the remaining students received.5 h/week of individual computer time. At the end of the school year, the 1-h group did significantly better than the.5-h group on a conditional rule-learning task. Future research should compare gains from structured languages like LOGO with those of unstructured languages and should use additional assessment techniques.
A Generative Middleware Specialization Process for Distributed Real-Time and Embedded Systems

General-purpose middleware must often be specialized for resource-constrained, real-time and embedded systems to improve their response-times, reliability, memory footprint, and even power consumption. Software engineering techniques, such as aspect-oriented programming (AOP), feature-oriented programming (FOP), and reflection make the specialization task simpler, albeit still requiring the system developer to manually identify the system invariants, and sources of performance and memory footprint bottlenecks that determine the required specializations. Specialization reuse is also hampered due to a lack of common taxonomy to document the recurring specializations. This paper presents the GeMS (Generative Middleware Specialization) framework to address these challenges. We present results of applying GeMS to a Distributed Real-time and Embedded (DRE) system case study that depict a 21-35% reduction in footprint, and a 36% improvement in performance while simultaneously alleviating 97% of the developer efforts in specializing middleware.
Neutrality Agreements and Article III Standing: Why Unite Here Local 355 v. Mulhall is Nonjusticiable

Next month, the Supreme Court will consider whether union-employer "neutrality agreements" run afoul of Section 302 of the Labor Management Relations Act. One facet of this dispute, however, has been overlooked: Unite Here Local 355 v. Mulhall is not a "case or controversy" at all. Martin Mulhall, the Florida casino worker hoping to block the enforcement of a neutrality agreement between his employer and Local 355, lacks standing.
Estimación de densidad de dos primates endémicos bolivianos, Callicebus olallae y Callicebus modestus

Bolivia’s two endemic primate species, Callicebus modestus and Callicebus olallae, live in fragmented forests in the savannas of the Beni. We estimated the d...