bluuebunny/crossref_metadata_2025 huggingface dataset:
Atomic Emission of Chlorine: Spectra from 200 to 900 nm by Sealed Inductively Coupled Plasma-Atomic Emission Spectroscopy
Authors: Jacksier Tracey , Barnes Ramon M.
Published: October 2009

Eighty-seven atomic chlorine lines and chlorine molecular spectra emitted in the 200–900 nm wavelength range are identified in a pure chlorine discharge generated at atmospheric pressure in a sealed inductively coupled plasma. Only small quantities of chlorine are needed for spectral evaluation because the flow rate is typically less than 20 mL/min.
FT-IR Step-Scan Photoacoustic Phase Analysis and Depth Profiling of Calcified Tissue
Authors: Sowa Michael G. , Mantsch Henry H.
Published: October 2009

Rapid-scan- and step-scan-based Fourier transform infrared photoacoustic depth profiling results of an extracted but intact human tooth are compared. The effects of various data processing methods are examined. Analysis of the phase dispersion of the photothermal signal along with spectral linearization is used to access the extent of photoacoustic saturation in the photoacoustic spectra. Phase-modulated/phase-resolved depth profiling methods are less prone to photoacoustic saturation and provide superior localization of the surface and subsurface absorbers distributed in the tooth enamel. Mid-infrared depth profiling studies of calcified tissues can aid in the understanding of degenerative bone diseases, bone growth, and modeling, as well as tissue mineralization.
Temperature Dependence of the Vibrational Spectra of Thallium(I) Alkanoates
Authors: García M. V. , Redondo M. I. , de la Fuente F. L. López , Cheda J. A. R. , Westrum E. F. , Fernández-Martín F.
Published: October 2009

IR spectroscopy has been used to model the stepwise melting process of nine T1(I) n-alkanoate salts from the solid phase into the isotropic liquid. This study has provided an explanation of the thermal effect observed by differential scanning and adiabatic calorimetry as an enhancement in the normal sigmate shape heat-capacity morphology. Infrared spectra show that these salts exist at low temperature as crystals with a subcell different from orthorhombic or monoclinic formation (no factor group splitting observed). In the lowest solid-to-solid phase transitions, the alkyl chains remain, mainly, in a totally trans-planar conformation, but the concentration of nonplanar conformers increases continuously as the temperature rises, and at a particular value (different for each compound), the CH2 wagging progression bands disappear. The temperature range at which this chain “melting” takes place coincides with the final steps of the calorimetric enhancement of the heat capacity. Changes in wavenumbers of some characteristic bands are observed in the infrared spectra at several phase transitions found by calorimetry. Because of its enhanced sensitivity to conformational order, Raman spectroscopy also was used for several alkanoate salts.
Comparison of Methodologies for the Determination of Excitation Temperatures of Plasma Support Gases
Authors: Walker A. L. , Curry D. L. , Fannin H. B.
Published: October 2009

Methodologies for the determination of excitation temperatures for the argon support gas in six inductively coupled plasma systems are compared. These methods include a Boltzmann plot, partial Boltzmann plots, a polynomial fit, and a Fermi-Dirac model. The temperature(s) and fitting statistics are reported for each method. Additionally, the theoretical basis for each method is briefly reviewed. All these methods, with the exception of the first and last, yield multiple excitation temperatures; however, the Fermi-Dirac model more closely models the observed population distribution of excited electronic states in the argon atom.
Infrared Chemical Micro-Imaging Assisted by Interactive Self-Modeling Multivariate Analysis
Authors: Guilment Jean , Markel Sharon , Windig Willem
Published: October 2009

In the analytical environment, spectral data resulting from analysis of samples often represent mixtures of several components. Extraction of information about pure components from that kind of mixture is a major problem, especially when reference spectra are not available. Self-modeling multivariate mixture analysis has been developed for this type of problem. In this paper, two examples will be used to show the potential of the technique for vibrational spectroscopy. Infrared microspectroscopic chemical imaging has been employed to improve spatial resolution for distinguishing differences between adjacent, nonidentical materials. The resolution of a 2- to 3- μm-thick inner layer, from a four-layer polymer laminate, has been achieved. The same approach has been utilized to extract pure component spectra out of a KBr pellet of a mixture of three compounds.
Calibration Methods for NIRS Instruments: A Theoretical Evaluation and Comparisons by Data Splitting and Simulations
Authors: Almøy Trygve , Haugland Espen
Published: October 2009

The properties of the recently proposed calibration method called restricted principal component regression (RPCR) were evaluated and compared with partial least-squares regression (PLSR) and two types of principal component regression (PCR1, selected according to the size of the eigenvalues, and PCR2, selected according to the t-value). RPCR can be considered a compromise between PCR and PLSR, since the first component of RPCR is equivalent to the first component of PLSR, while the rest can be regarded as principal components on a space orthogonal to the first. The methods showed almost the same properties when the irrelevant components had small eigenvalues. The prediction error of RPCR selected according to the size of the eigenvalues was intermediate to those of PCR1 and PLSR when the number of components was low, while RPCR and PCR1 nearly coincided when the number of components exceeded the number of relevant ones. The prediction error minimum was about the same for RPCR, PCR1, and PLSR, but the minimum of PLSR was obtained when a lower number of components were included in the calibration model.
Investigation of Electrical and Optical Subtractions Using Two Input-Port and Two Output-Port FT-IR Spectrometers
Authors: Laroche Gaétan , Giroux Jean , Bordeleau Alain , Garneau Jean-Marc
Published: October 2009

Two FT-IR spectrometers, each using two input ports and two output ports, have been used to minimize the effect of background noise and source fluctuation noise in infrared emission spectra of various sources. Blackbody sources, propane/air flames, and infrared flares have been studied, and spectra were recorded in the spectral region ranging from 1.7 to 5 μm. With the use of the two input-port and one output-port configurations, it was found that real-time optical subtraction could generate 80% background-noise-free spectra. When the spectrometers were operated in the one input-port and two output-port configurations, spectra that were free of source fluctuation noise were obtained with the use of real-time electrical subtraction of signals measured at both detectors. New signal processing techniques have thus been developed. An increase in the signal-to-fluctuation-noise ratio by a factor of seven has been observed in the interferograms, which in turn leads to a 2 × increase of the signal-to-noise ratio in the corresponding spectra. During this signal processing sequence requiring the use of two analog-to-digital converters (ADC) (one for each detector channel), intensity information was then lost, so that no calibrated spectra could be measured. However, with the use of a single-channel ADC, it was shown that, by a process of simply subtracting signals recorded from both detectors operated under similar amplifier gain, fluctuation noise could be partly removed and intensity information could also be retained. In conjunction with the high scanning velocity of the interferometer (60 scans/s at a 16-cm−1 resolution), this technique has proven to be very useful in measuring emission spectra of highly fluctuating infrared sources, such as flares.
Infrared Intensities of Liquids XV: Infrared Refractive Indices from 8000 to 350 cm−1, Absolute Integrated Intensities, Transition Moments, and Dipole Moment Derivatives of Methanol-d, at 25°C
Authors: Bertie John E. , Zhang Shuliang L.
Published: October 2009

This paper reports infrared absorption intensities of liquid methanol- d, CH3OD, at 25°C, between 8000 and 350 cm−1 Measurements were made by multiple attenuated total reflection spectroscopy with the use of the CIRCLE cell, and by transmission spectroscopy with a variable-path-length cell with CaF2 windows. The results of these two methods agree excellently and were combined to yield an imaginary refractive index spectrum, k(ν˜) vs. ν˜, between 6187 and 350 cm−1. The imaginary refractive index spectrum was arbitrarily set to zero between 6187 and 8000 cm−1 where k is always less than 2 × 10−6, in order that the real refractive index can be calculated below 8000 cm−1 by Kramers-Krönig transformation. The results are reported as graphs and as tables of the real and imaginary refractive indices between 8000 and 350 cm−1, from which all other infrared properties of liquid methanol- d can be calculated. The accuracy is estimated to be ± 3% below 5900 cm−1 and ± 10% above 5900 cm−1 for the imaginary refractive index and better than ± 0.5% for the real refractive index. In order to obtain molecular information from the refractive indices, the spectrum of the imaginary polarizability multiplied by wavenumber, ν˜ vs. ν˜, was calculated under the assumption of the Lorentz local field. The area under this ν˜ spectrum was separated into the integrated intensities of different vibrations. Molecular properties were calculated from these integrated intensities—specifically, the transition moments and dipole moment derivatives of the molecules in the liquid, the latter under the harmonic approximation. The availability of the spectra of both CH3OH and CH3OD enables the integrated intensities and the molecular properties of the C-H, O-H, O-D, and C-O stretching and CH3 deformation vibrations to be determined with confidence to a few percent. Further work with isotopic molecules is needed to improve the reliability of the integrated intensities of the C-O-H(D) in-plane bending, H-C-O-H(D) torsion, and CH3 rocking vibrations.
Confocal Raman Microspectroscopy Using a Stigmatic Spectrograph and CCD Detector
Authors: Williams K. P. J. , Pitt G. D. , Batchelder D. N. , Kip B. J.
Published: October 2009

Confocal Raman microspectroscopy has previously used pinholes placed at the back focal plane of the microscope to provide depth resolution along the optical axis. The process of optimizing the pinhole alignment can often be difficult and time-consuming. We demonstrate a different approach to setting up a confocal Raman microscope using a stigmatic spectrograph and a CCD detector. This arrangement is easy to use and provides a depth resolution of ∼2 μm.
Evaluation of a Microcavity Hollow Cathode Discharge Emission Source
Authors: Morgan C. A. , Davis C. L. , Smith B. W. , Winefordner J. D.
Published: October 2009

A microcavity hollow cathode discharge emission source has been designed and evaluated for ultratrace analysis of sub-μL samples of solution residues. It was found that sample drying time and cathode precondition had a significant effect on the signal-to-background and signal-to-noise ratios. Detection limits for Cu and Pb were determined to be 10 pg and 210 fg, respectively.
Influence of the Nitrobenzene Extraction Technique on the Protein Molecule Conformation
Authors: Weizhong Ke , Jianzhong Wu
Published: October 2009

The Raman spectra of lysozyme, ribonuclease, and BSA (bovine serum albumin) in aqueous solution extracted by nitrobenzene and the ultraviolet visible absorption spectra of BSA in aqueous solution have been studied. It has been proven that the structure of all the characteristic Raman and UV bands of BAS protein in aqueous solution is due to α;-helical and random-coil conformations. The tyrosine residue is “exposed”, and the conformation of the carbon atoms in the disulfide bridge c-c-s-s-c-c is trans-gauche-gauche. The influence of adding nitrobenzene to lysozyme, ribonuclease, and BSA aqueous solution has been studied. The study indicated that nitrobenzene treatment of protein aqueous solution is an efficient means for obtaining better Raman spectra.
Application of an ATR Method in Raman Spectroscopy
Authors: Futamata M. , Borthen P. , Thomassen J. , Schumacher D. , Otto A.
Published: October 2009

The attenuated total reflection (ATR) method in a prism/gap/metal configuration was used in Raman spectroscopy of molecules adsorbed on silver to improve the detection limit. The thickness of the air gap was controlled between ΛL/2 and 2ΛL (ΛL: wavelength of the incident light) with a biaxial suspension. All the scattered light within the SPP cone was collected with a Weierstrass prism and a 1:1 objective. The enhancement factor of the Raman scattering intensity for the use of in- and out-coupling of the SPP was found to be 134 and 70 for carbon and copper-phthalocyanine (CuPc), respectively. The scattered light inside the SPP cone is additionally enhanced by the interference in the air gap. This interference is also useful to enhance the Raman signals of the adsorbates. Nearly the same enhancement factor was observed for the different symmetry species of vibrations in CuPc, because CuPc is randomly oriented with respect to the silver surface normal.
Cognitive Decline in Alzheimer's Disease Is Associated with Selective Changes in Calcineurin/NFAT Signaling
Authors: Abdul Hafiz Mohmmad , Sama Michelle A. , Furman Jennifer L. , Mathis Diana M. , Beckett Tina L. , Weidner Adam M. , Patel Ela S. , Baig Irfan , Murphy M. Paul , LeVine Harry , Kraner Susan D. , Norris Christopher M.
Published: October 2009

Upon activation by calcineurin, the nuclear factor of activated T-cells (NFAT) translocates to the nucleus and guides the transcription of numerous molecules involved in inflammation and Ca2+dysregulation, both of which are prominent features of Alzheimer's disease (AD). However, NFAT signaling in AD remains relatively uninvestigated. Using isolated cytosolic and nuclear fractions prepared from rapid-autopsy postmortem human brain tissue, we show that NFATs 1 and 3 shifted to nuclear compartments in the hippocampus at different stages of neuropathology and cognitive decline, whereas NFAT2 remained unchanged. NFAT1 exhibited greater association with isolated nuclear fractions in subjects with mild cognitive impairment (MCI), whereas NFAT3 showed a strong nuclear bias in subjects with severe dementia and AD. Similar to NFAT1, calcineurin-Aα also exhibited a nuclear bias in the early stages of cognitive decline. But, unlike NFAT1 and similar to NFAT3, the nuclear bias for calcineurin became more pronounced as cognition worsened. Changes in calcineurin/NFAT3 were directly correlated to soluble amyloid-β (Aβ(1-42)) levels in postmortem hippocampus, and oligomeric Aβ, in particular, robustly stimulated NFAT activation in primary rat astrocyte cultures. Oligomeric Aβ also caused a significant reduction in excitatory amino acid transporter 2 (EAAT2) protein levels in astrocyte cultures, which was blocked by NFAT inhibition. Moreover, inhibition of astrocytic NFAT activity in mixed cultures ameliorated Aβ-dependent elevations in glutamate and neuronal death. The results suggest that NFAT signaling is selectively altered in AD and may play an important role in driving Aβ-mediated neurodegeneration.
Processing of Auditory Location Changes after Horizontal Head Rotation
Authors: Altmann Christian F. , Wilczek Esther , Kaiser Jochen
Published: October 2009

Under natural conditions, our sound localization capabilities enable us to move constantly while keeping a stable representation of our auditory environment. However, since most auditory studies focus on head-restrained conditions, it is still unclear whether neurophysiological markers of auditory spatial processing reflect representation in a head-centered or an allocentric coordinate system. Therefore, we used human electroencephalography to test whether the spatial mismatch negativity (MMN) as a marker of spatial change processing is elicited by changes of sound source position in terms of a head-related or an allocentric coordinate system. Subjects listened to a series of virtually localized band-passed noise tones and were occasionally cued visually to conduct horizontal head movements. After these head movements, we presented deviants either in terms of a head-centered or an allocentric coordinate system. We observed significant MMN responses to the head-related deviants only but a change-related novelty P3-like component for both head-related and allocentric deviants. These results thus suggest that the spatial MMN is associated with a representation of auditory space in a head-related coordinate system and that the integration of motor output and auditory input possibly occurs at later stages of the auditory “where” processing stream.
Distinct Domains within PSD-95 Mediate Synaptic Incorporation, Stabilization, and Activity-Dependent Trafficking
Authors: Sturgill James F. , Steiner Pascal , Czervionke Brian L. , Sabatini Bernardo L.
Published: October 2009

The postsynaptic density (PSD) consists of a lattice-like array of interacting proteins that organizes and stabilizes receptors, ion channels, structural, and signaling proteins necessary for synaptic function. To study the stabilization of proteins within this structure and the contribution of these proteins to the integrity of the PSD, we tagged synaptic proteins with PAGFP (photoactivatable green fluorescent protein) and used combined two-photon laser-scanning microscopy and two-photon laser photoactivation to measure their rate of turnover in individual spines of rat CA1 pyramidal neurons. We find that PSD-95 is highly stable within the spine, more so than other PSD-associated proteins such as CaMKIIα, CaMKIIβ, GluR2, and Stargazin. Analysis of a series of PSD-95 mutants revealed that distinct domains stabilize PSD-95 within the PSD and contribute to PSD formation. Stabilization of PSD-95 within the PSD requires N-terminal palmitoylation and protein interactions mediated by the first and second PDZ domains, whereas formation of a stable lattice of PSD-95 molecules within the PSD additionally requires the C-terminal SH3 domain. Furthermore, in a PDZ domain 1 and 2 dependent manner, activation of NMDA receptors with a chemical long-term depression protocol rapidly destabilizes PSD-95 and causes a subset of the PSD-95 molecules previously anchored in the spine to be released. Thus, through the analysis of rates of exchange of synaptic PSD-95, we determine separate domains of PSD-95 that play specific roles in establishing a stable postsynaptic lattice, in allowing proteins to enter this lattice, and in reorganizing this structure in response to plasticity-inducing stimuli.
Direction-Specific Disruption of Subcortical Visual Behavior and Receptive Fields in Mice Lacking the β2 Subunit of Nicotinic Acetylcholine Receptor
Authors: Wang Lupeng , Rangarajan Krsna V. , Lawhn-Heath Courtney A. , Sarnaik Rashmi , Wang Bor-Shuen , Liu Xiaorong , Cang Jianhua
Published: October 2009

Retinotopic mapping is a basic feature of visual system organization, but its role in processing visual information is unknown. Mutant mice lacking the β2 subunit of nicotinic acetylcholine receptor have imprecise maps in both visual cortex (V1) and the superior colliculus (SC) due to the disruption of spontaneous retinal activity during development. Here, we use behavioral and physiological approaches to study their visual functions. We find that β2−/− mice fail to track visual stimuli moving along the nasotemporal axis in a subcortical optomotor behavior, but track normally along the dorsoventral axis. In contrast, these mice display normal acuity along both axes in the visual water task, a behavioral test of cortical functions. Consistent with the behavioral results, we find that V1 neurons in β2−/− mice have normal response properties, while SC neurons have disrupted receptive fields, including enlarged structure and decreased direction and orientation selectivity along the nasotemporal axis. The subcortical-specific deficits indicate that retinotopic map disruption has different impacts on the development of functional properties in V1 and the SC.
Cerebrovascular Cyclooxygenase-1 Expression, Regulation, and Role in Hypothalamic-Pituitary-Adrenal Axis Activation by Inflammatory Stimuli
Authors: García-Bueno Borja , Serrats Jordi , Sawchenko Paul E.
Published: October 2009

Systemic injection of lipopolysaccharide (LPS) is a widely used model of immune/inflammatory challenge, which can invoke a host of CNS responses, including activation of the hypothalamic-pituitary-adrenal (HPA) axis. Inducible vascular prostaglandin E2(PGE2) synthesis by endothelial (ECs) and/or perivascular cells (PVCs) (a macrophage-derived vascular cell type) is implicated in the engagement of HPA and other CNS responses, by virtue of their capacity to express cyclooxygenase-2 (COX-2) and microsomal PGE2synthase-1. Evidence from genetic and pharmacologic studies also supports a role for the constitutively expressed COX-1 in inflammation-induced activation of the HPA axis, although histochemical evidence to support relevant localization(s) and regulation of COX-1 expression is lacking. The present experiments fill this void in showing that COX-1 immunoreactivity (IR) and mRNA are detectable in identified PVCs and parenchymal microglia under basal conditions and is robustly expressed in these and ECs 1–3 h after intravenous injection of LPS (2 μg/kg). Confocal and electron microscopic analyses indicate distinct cellular/subcellular localizations of COX-1-IR in the three cell types. Interestingly, COX-1 expression is enhanced in ECs of brain PVC-depleted rats, supporting an anti-inflammatory role of the latter cell type. Functional involvement of COX-1 is indicated by the observation that central, but not systemic, pretreatment with the selective COX-1 inhibitor SC-560 attenuated the early phase of LPS-induced increases in adrenocorticotropin and corticosterone secretion. These findings support an involvement of COX-1 in bidirectional interplay between ECs and PVCs in initiating vascular PGE2and downstream HPA response to proinflammatory challenges.
Modulation of Perineuronal Nets and Parvalbumin with Developmental Song Learning
Authors: Balmer Timothy S. , Carels Vanessa M. , Frisch Jillian L. , Nick Teresa A.
Published: October 2009

Neural circuits and behavior are shaped during developmental phases of maximal plasticity known as sensitive or critical periods. Neural correlates of sensory critical periods have been identified, but their roles remain unclear. Factors that define critical periods in sensorimotor circuits and behavior are not known. Birdsong learning in the zebra finch occurs during a sensitive period similar to that for human speech. We now show that perineuronal nets, which correlate with sensory critical periods, surround parvalbumin-positive neurons in brain areas that are dedicated to singing. The percentage of both total and parvalbumin-positive neurons with perineuronal nets increased with development. In HVC (this acronym is the proper name), a song area important for sensorimotor integration, the percentage of parvalbumin neurons with perineuronal nets correlated with song maturity. Shifting the vocal critical period with tutor song deprivation decreased the percentage of neurons that were parvalbumin positive and the relative staining intensity of both parvalbumin and a component of perineuronal nets. Developmental song learning shares key characteristics with sensory critical periods, suggesting shared underlying mechanisms.
Functional Properties of Synaptic Transmission in Primary Sense Organs
Authors: Singer Joshua H. , Glowatzki Elisabeth , Moser Tobias , Strowbridge Ben W. , Bhandawat Vikas , Sampath Alapakkam P.
Published: October 2009

Sensory receptors transduce physical stimuli in the environment into neural signals that are interpreted by the brain. Although considerable attention has been given to how the sensitivity and dynamic range of sensory receptors is established, peripheral synaptic interactions improve the fidelity with which receptor output is transferred to the brain. For instance, synapses in the retina, cochlea, and primary olfactory system use mechanisms that fine-tune the responsiveness of postsynaptic neurons and the dynamics of exocytosis; these permit microcircuit interactions to encode efficiently the output of sensory receptors with the fidelity and dynamic range necessary to extract the salient features of the physical stimuli. The continuous matching of presynaptic and postsynaptic responsiveness highlight how the primary sensory organs have been optimized and can be modulated to resolve sparse sensory signals and to encode the entire range of receptor output.
RbpjCell Autonomous Regulation of Retinal Ganglion Cell and Cone Photoreceptor Fates in the Mouse Retina
Authors: Riesenberg Amy N. , Liu Zhenyi , Kopan Raphael , Brown Nadean L.
Published: October 2009

Vertebrate retinal progenitor cells (RPCs) are pluripotent, but pass through competence states that progressively restrict their developmental potential (Cepko et al., 1996; Livesey and Cepko, 2001; Cayouette et al., 2006). In the rodent eye, seven retinal cell classes differentiate in overlapping waves, with RGCs, cone photoreceptors, horizontals, and amacrines forming predominantly before birth, and rod photoreceptors, bipolars, and Müller glia differentiating postnatally. Both intrinsic and extrinsic factors regulate each retinal cell type (for review, see Livesey and Cepko, 2001). Here, we conditionally deleted the transcription factorRbpj, a critical integrator of multipleNotchsignals (Jarriault et al., 1995; Honjo, 1996; Kato et al., 1997; Han et al., 2002), during prenatal mouse retinal neurogenesis. Removal ofRbpjcaused reduced proliferation, premature neuronal differentiation, apoptosis, and profound mispatterning. To determine the cell autonomous requirements forRbpjduring RGC and cone formation, we marked Cre-generated retinal lineages with GFP expression, which showed thatRbpjautonomously promotes RPC mitotic activity, and suppresses RGC and cone fates. In addition, the progressive loss ofRbpj−/− RPCs resulted in a diminished progenitor pool available for rod photoreceptor formation. This circumstance, along with the overproduction ofRbpj−/− cones, revealed that photoreceptor development is under homeostatic regulation. Finally, to understand how theNotchpathway regulates the simultaneous formation of multiple cell types, we compared the RGC and cone phenotypes ofRbpjtoNotch1(Jadhav et al., 2006b; Yaron et al., 2006),Notch3, andHes1mutants. We found particular combinations ofNotchpathway genes regulate the development of each retinal cell type.
Convergence of Cranial Visceral Afferents within the Solitary Tract Nucleus
Authors: McDougall Stuart J. , Peters James H. , Andresen Michael C.
Published: October 2009

Primary afferent axons within the solitary tract (ST) relay homeostatic information via glutamatergic synapses directly to second-order neurons within the nucleus of the solitary tract (NTS). These primary afferents arise from multiple organ systems and relay multiple sensory modalities. How this compact network organizes the flow of primary afferent information will shape central homeostatic control. To assess afferent convergence and divergence, we recorded ST-evoked synaptic responses in pairs of medial NTS neurons in horizontal brainstem slices. ST shocks activated EPSCs along monosynaptic or polysynaptic pathways. Gradations in shock intensity discriminated multiple inputs and stimulus recruitment profiles indicated that each EPSC was unitary. In 24 pairs, 75% were second-order neurons with 64% receiving one direct ST input with the remainder receiving additional convergent ST afferent inputs (22% two; 14% three monosynaptic ST-EPSCs). Some (34%) second-order neurons received polysynaptic EPSCs. Neurons receiving only higher-order inputs were uncommon (13%). Most ST-EPSCs were completely independent, but 4 EPSCs of a total of 81 had equal thresholds, highly correlated latencies, and synchronized synaptic failures consistent with divergence from a single source ST axon or from a common interneuron producing a pair of polysynaptic EPSCs. We conclude that ST afferent inputs are remarkably independent with little evidence of substantial shared information. Individual cells receive highly focused information from the viscera. Thus, afferent excitation of second-order NTS neurons is generally dominated by single visceral afferents and therefore focused on a single afferent modality and/or organ region.
Positive and Negative Regulation of Odor Receptor Gene Choice in Drosophila by Acj6
Authors: Bai Lei , Goldman Aaron L. , Carlson John R.
Published: October 2009

Little is known about how individual olfactory receptor neurons (ORNs) select, from among many odor receptor genes, which genes to express. Abnormal chemosensory jump 6 (Acj6) is a POU domain transcription factor essential for the specification of ORN identity and odor receptor (Or) gene expression in theDrosophilamaxillary palp, one of the two adult olfactory organs. However, the mechanism by which Acj6 functions in this process has not been investigated. Here, we systematically examine the role of Acj6 in the maxillary palp and in a major subset of antennal ORNs. We define an Acj6 binding site by a reiterativein vitroselection process. The site is found upstream ofOrgenes regulated by Acj6, and Acj6 binds to the site inOrpromoters. Mutational analysis shows that the site is essential forOrregulationin vivo. Surprisingly, a novel ORN class inacj6adults is found to arise from ectopic expression of a larvalOrgene, which is repressed in wild type via an Acj6 binding site. Thus, Acj6 acts directly in the process of receptor gene choice; it plays a dual role, positive and negative, in the logic of the process, and acts in partitioning the larval and adult receptor repertoires.
New Insights in the Biology of BDNF Synthesis and Release: Implications in CNS Function
Authors: Greenberg Michael E. , Xu Baoji , Lu Bai , Hempstead Barbara L.
Published: October 2009

BDNF has pleiotropic effects on neuronal development and synaptic plasticity that underlie circuit formation and cognitive function. Recent breakthroughs reveal that neuronal activity regulates BDNF cell biology, includingBdnftranscription, dendritic targeting and trafficking of BDNF mRNA and protein, and secretion and extracellular conversion of proBDNF to mature BDNF. Defects in these mechanisms contribute differentially to cognitive dysfunction and anxiety-like behaviors. Here we review recent studies, presented at a symposium at Neuroscience 2009, that describe regulatory mechanisms that permit rapid and dynamic refinement of BDNF actions in neurons.
The β-Secretase Enzyme BACE in Health and Alzheimer's Disease: Regulation, Cell Biology, Function, and Therapeutic Potential
Authors: Vassar Robert , Kovacs Dora M. , Yan Riqiang , Wong Philip C.
Published: October 2009

The β-amyloid (Aβ) peptide is the major constituent of amyloid plaques in Alzheimer's disease (AD) brain and is likely to play a central role in the pathogenesis of this devastating neurodegenerative disorder. The β-secretase, β-site amyloid precursor protein cleaving enzyme (BACE1; also called Asp2, memapsin 2), is the enzyme responsible for initiating Aβ generation. Thus, BACE is a prime drug target for the therapeutic inhibition of Aβ production in AD. Since its discovery 10 years ago, much has been learned about BACE. This review summarizes BACE properties, describes BACE translation dysregulation in AD, and discusses BACE physiological functions in sodium current, synaptic transmission, myelination, and schizophrenia. The therapeutic potential of BACE will also be considered. This is a summary of topics covered at a symposium held at the 39th annual meeting of the Society for Neuroscience and is not meant to be a comprehensive review of BACE.
Neurotransmitters, Receptors, and Second Messengers Galore in 40 Years
Authors: Snyder Solomon H.
Published: October 2009

The past four decades have witnessed extraordinary advances in the molecular understanding of neurotransmitters, their receptors, and second messengers. This essay highlights a selected group of particular notable discoveries, emphasizing seminal findings that have transformed thinking in the field.
Role of Boron TED and Series Resistance in SiGe/Si Heterojunction pMOSFETs
Authors: Kim Yonghyun , Kang Chang Yong , Lee Se-Hoon , Majhi Prashant , Min Byoung-Gi , Lee Ki-Seung , Ahn Donghwan , Banerjee Sanjay K.
Published: October 2009

We investigate boron transient enhanced diffusion (TED) and series resistance in SiGe/Si heterojunction channel pMOSFET. The stress gradient at the SiGe/Si interface near the gate edge in high Ge concentrations are found to determine boron TED as well as extension junction shape, which has a significant impact on the parasitic LDD and source/drain (S/D) series resistance. In addition, high Ge concentrations in the epitaxial SiGe layer on top of Si substrate result in a high sheet resistance during a 1000°C/5s rapid thermal processing (RTP), which is mainly due to alloy scattering and interface roughness scattering.
First-Principles study of HfO2/:GaAs interface passivation by Si and Ge
Authors: Wang Weichao , Xiong Ka , Lee Geunsik , Huang Min , Wallace Robery M. , Cho Kyeongjae
Published: October 2009

We investigated the HfO2:GaAs interface electronic structure and interface passivation by first principles calculations. The HfO2:GaAs interface of HfO2 terminated with four O atoms and GaAs terminated two Ga atoms is found to be the most energetically favorable. It is found that the interface states mainly arise from the interfacial charge mismatch, more specifically from the electron loss of interfacial As. Si or Ge as an interfacial passivating layer helps to maintain the charge of interfacial As and hence reduce the interface states.
Hafnia surface and high-k gate stacks
Authors: Luo Xuhui , Demkov Alex , Sharia Onise , Bersuker Gennadi
Published: October 2009

Hafnium dioxide that belongs to a class of metal oxides with a high dielectric constant or high-k dielectrics has been recently introduced as a gate dielectric in field effect transistors. We report a theoretical study of structural and electronic properties of hafnia surface, and the electronic structure and band alignment at hafnia interfaces with metals, oxides and semiconductors that are crucial in gate stack engineering.
Structural, Optical and Electrical Characterization of Thermally Evaporated TlBr Thin Films
Authors: Destefano Natália , Mulato Marcelo
Published: October 2009

This paper presents the study related to the production of TlBr thin films. Films produced by thermal evaporation present better structural properties than those produced by spray pyrolysis. The main XRD peak of the evaporated films correspond to the (100) plane, whose structure is columnar as revealed by cross section SEM. The thickness decreases with increasing deposition height. Optical band gap of 3.0 eV and electrical resistivities about 109 Ωcm were obtained. EDS reveals a reduction in the amount of Br in the final films. One order of magnitude was obtained for the photo-to-dark current ratio when irradiation in the medical diagnosis X-ray mammography energy range was used.
Various methods used to etch titanium dioxide columnar thin films
Authors: Kupsta Martin Roman , Taschuk Mike , Brett Michael J. , Sit Jeremy C.
Published: October 2009

A dry etch recipe was developed for porous nanostructured TiO2 thin films fabricated using glancing angle deposition (GLAD). Unlike wet chemical etches, the technique reported here preserves the vertical post nanostructure, eliminating clumping. A highly controllable and easily tailored reactive ion etching process with CF4 alone, or combined with O2, was investigated. The anisotropic etch modifies the morphology and density of standard GLAD films, which is of interest for sensing applications.
Characterizing the Two-Dimensional Doping Concentration inside Silicon-Nanowires Using Scanning Spreading Resistance Microscopy
Authors: Hantschel Thomas , Schulz Volker , Schulze Andreas , Angeletti Esteban , Guder Firat , Schmidt Volker , Senz Stephan , Eyben Pierre , Vandervorst Wilfried
Published: October 2009

The characterization of doped regions inside silicon nanowire structures poses a challenge which must be overcome if these structures are to be incorporated into future electronic devices. Precise cross-sectioning of the nanowire along its longitudinal axis is required, followed by two-dimensional electrical measurements with nanometer spatial resolution. The authors have developed an approach to cross-section silicon nanowires and to characterize them by scanning spreading resistance microscopy (SSRM). This paper describes a cleaving- and polishing-based cross-sectioning method for silicon nanowires. High resolution SSRM measurements are demonstrated for epitaxially grown and etched silicon nanowires.
The Role of the Surface Coverage on the Structural and the Electronic Properties of TiO2 Nanocrystals
Authors: Iacomino Amilcare , Cantele Giovanni , Trani Fabio , Ninno Domenico , Marri Ivan , Ossicini Stefano
Published: October 2009

The titanium dioxide (TiO2) complexes are widely investigated for their striking and multipurpose capabilities. The TiO2 key feature lies in its photocatalytic activity for several reactions of social (bioengineering, environmental and artistic protection, pollution containment) and commercial (photovoltaic, alternative-energy, gas sensing) interests. The possibility to enhance specific reactions at the nanoscale by a fine tuning of the nano-sized single crystals properties boosted in the last decade the scientific research. Thus a theoretical understanding of the fundamental properties of TiO2 nanocrystals became necessary to predict and expedite the experimental effords.
We present here a characterization of TiO2 0D nanoclusters and 1D nanowires in the framework of ab initio DFT calculations. Based on both theoretical and experimental evidences we defined a stoichiometric TiO2 NC by modifying a perfect bipyramidal morphology and then used this NC as a chain repetition unit in the NW. We analyzed the effect of the surface coverage by functionalizing dangling bonds with simple adsorbates (dissociated water and hydrogens) modeling two acidic environments. These terminations are important to model the basical interactions of TiO2 nanosystems with the hydration sphere, which is always found to surround the nanosamples and toaffect their photocatalytic activity. We thus address the electronic reorganization and the surface weight in determining the global features of the nanostructures. The structural reconstruction is found to depend on the surface coverage and the experimental evidences on the structural variations can be explained by a topological analysis of the Ti-O bonds. Quantum confinement effects in the electronic properties are observed through the bandgap widening and the discretization of the energy distribution, but the surface competes to determine the energy dispersion of the electronic levels. The hydrogenated nanocrystals do show occupied levels at the bottom of the coduction bands, thus leading to metallic nanowires in one dimension. Whereas in the hydrogenated cluster such levels present a localized charge distribution with respect to the whole structure and they are also similar for the atomic orbital character and energy position to the defect states obtained by oxygens desorption. From the analysis of the electronic density of states we found that Ti-H bonds induce in-gap states above the valence bands, whereas hydration leads to occupied states that shift the valence bands to lower binding energies. Formation energy calculations reveal that surface hydration leads to the most stable nanocrystals, in agreement with the experimental findings that water coverage stabilizes the surface.
Thermomechanical Properties and Shape-Memory Capability of Drug Loaded Semi-Crystalline Polyestermethacrylate Networks
Authors: Neffe Axel Thomas , Hanh Bui Duc , Steuer Susi , Wischke Christian , Lendlein Andreas
Published: October 2009

Polymer networks synthesized by UV-curing of Oligo[(ε-caprolactone)-co-glycolide]dimethacrylates are hydolytically degradable. Their architecture with covalent netpoints and crystallizable domains is the molecular basis for the potential shape-memory capability. The molecular weight and glycolide content of the oligomeric precursors can be varied over a broad range of compositions to tailor the thermomechanical properties of the polymer network while having only a minor influence on the shape-memory effect. Recently, drug incorporation adding controlled drug release as further functionality to the polymer network was demonstrated [4]. Here, enoxacin and ethacridine lactate as test drugs were incorporated into the networks by soaking. Alternatively, defined amounts of ethacridine lactate were mixed with the precursors, which were subsequently crosslinked to the drug containing networks. The composition of the oligomeric precursors in molecular weight between 3800 and 12800 g�mol-1 and in glycolide content ϝG between 0 and 30 mol-% to explore the influence of the drug incorporation on networks with varying compositions while retaining properties and functionalities. Polymer networks prepared from precursors with ϝG ? 14 mol-% and Mn ? 6900 g�mol-1 have a Tsw of 35-52 �C and sufficient crystallinity to ensure a high shape fixity in the programming step. These limits have to be kept to ensure the desired multifunctionality, otherwise drug incorporation can have an undesired influence on thermal, mechanical, and shape-memory properties.
Mass Problems and Measure-Theoretic Regularity
Authors: Simpson Stephen G.
Published: October 2009

A well known fact is that every Lebesgue measurable set is regular, i.e., it includes an Fσ set of the same measure. We analyze this fact from a metamathematical or foundational standpoint. We study a family of Muchnik degrees corresponding to measuretheoretic regularity at all levels of the effective Borel hierarchy. We prove some new results concerning Nies's notion of LR-reducibility. We build some ω-models of RCA0 which are relevant for the reverse mathematics of measure-theoretic regularity.
Games for Truth
Authors: Welch P. D.
Published: October 2009

We represent truth sets for a variety of the well known semantic theories of truth as those sets consisting of all sentences for which a player has a winning strategy in an infinite two person game. The classifications of the games considered here are simple, those over the natural model of arithmetic being all within the arithmetical class of .
Are Images of Exercising Related to Feeling States?
Authors: Cumming Jennifer , Stanley Damian M.
Published: October 2009

This study examined the relationships between different types of exercise imagery and feeling states, and determined whether exercise behavior moderated these relationships. Following an exercise session, 162 participants (97 females, 65 male; Mage = 23.84, SD = 7.09) completed the Exercise Imagery Inventory (Giacobbi, Hausenblas, & Penfield, 2005), the Exercise-Induced Feeling Inventory (Gauvin & Rejeski, 1993), and the Leisure-Time Exercise Questionnaire (Godin & Shephard, 1985). Positive feeling states were predicted by increased use of exercise feelings imagery. However, appearance-health imagery acted as a suppressor variable to enhance the magnitude of relationship with revitalization and tranquility. Moreover, technique imagery partially mediated the relationship with positive engagement. Finally, moderated hierarchical multiple regressions followed by simple slope analysis indicated that the positive relationship between exercise feelings imagery and revitalization was only significant for participants who exercised less. This study provides empirical evidence that the relationship between imagery and feeling states is moderated by exercise behavior and suggests that imagery interventions for enhancing the positive exercise-induced feeling states might yield the most pronounced benefits for less active individuals.
The effects of nitrogen on protein, oil and trypsin inhibitor content of soybean
Authors: Peric Vesna , Srebric Mirjana , Jankuloski Ljupcho , Jankulovska Mirjana , Zilic Sladjana , Kandic Vesna , Mladenovic-Drinic Snezana
Published: October 2009

Nitrogen fertilization have influence on protein, oil and trypsin inhibitor content of different soybean genotypes. Seed protein content was increased over control by 60 kg ha-1 nitrogen while trypsin inhibitor was reduced by all treatmens (30, 60,90 N kg ha-1) as compared to controls. Significant genetic variation in TI was found both within the genotype class with the Kunitz inhibitor present as well as within the class lacking this inhibitor. Genotypes containing the Kunitz trypsin inhibitor protein (KTI) exhibit a higher TI than genotypes lacking this protein, however, in both groups of genotypes TI was similary affected by nitrogen application. Oil content was reduced following nitrogen fertilisation.
Phenotypic reaction of wheat grown on different soil types
Authors: Dimitrijevic Miodrag , Petrovic Sofija , Mladenov Novica , Belic Milivoj , Hristov Nikola , Banjac Borislav , Vukosavljev Mirjana
Published: October 2009

Phenotypic variation of nine wheat varieties under different growing conditions was followed. Trials were conducted on solonetz, humoglay and black soil. The yield, as well as, the plant height, spike length and harvest index were studied. The effect of different environments on varietals phenotypic variability, with the emphasis on genotype by environment interaction, was analyzed using AMMI model.
The effect of yield components on grain yield in different progeny types of an F3 maize population
Authors: Stojkovic Slavisa , Deletic Nebojsa , Biberdzic Milan , Aksic Miroljub , Bekovic Dragoljub
Published: October 2009

This paper deals with the investigation of S1 and HS progenies obtained from an F3 maize population. Those two progeny groups were created in 2004, and field trials were carried out in the period 2005-2006 at three locations near Aleksinac, Leskovac, and Krusevac, in RCB design. After genotypic correlation coefficients were calculated, they were used to calculate path coefficients and multiple determination coefficients. Analysis of path coefficients showed significant direct effects of the all studied traits in both S1 and HS progeny types. In S1 progenies indirect effects were significant for the all paths, except for percent of stalk and root lodged plants through 1000 grain mass, 1000 grain mass through percent of stalk and root lodged plants, and for 1000 grain mass through number of grain rows. The strongest direct effect on grain yield in HS progenies was shown by percent of stalk and root lodged plants (0.68**), while number of grains per row gave the strongest negative direct effect on grain yield (-0.97**). Multiple determination coefficients were significant for the most of independent variables' combinations in both progeny types. Numerous combinations composed of just few traits showed joint effects almost equal to the one showed by all seven independent variables.