bluuebunny/crossref_metadata_2025 huggingface dataset:
The Sushi Domains of GABABReceptors Function as Axonal Targeting Signals
Authors: Biermann Barbara , Ivankova-Susankova Klara , Bradaia Amyaouch , Abdel Aziz Said , Besseyrias Valerie , Kapfhammer Josef P. , Missler Markus , Gassmann Martin , Bettler Bernhard
Published: January 2010

GABABreceptors are the G-protein-coupled receptors for GABA, the main inhibitory neurotransmitter in the brain. Two receptor subtypes, GABAB(1a,2)and GABAB(1b,2), are formed by the assembly of GABAB1aand GABAB1bsubunits with GABAB2subunits. The GABAB1bsubunit is a shorter isoform of the GABAB1asubunit lacking two N-terminal protein interaction motifs, the sushi domains. Selectively GABAB1aprotein traffics into the axons of glutamatergic neurons, whereas both the GABAB1aand GABAB1bproteins traffic into the dendrites. The mechanism(s) and targeting signal(s) responsible for the selective trafficking of GABAB1aprotein into axons are unknown. Here, we provide evidence that the sushi domains are axonal targeting signals that redirect GABAB1aprotein from its default dendritic localization to axons. Specifically, we show that mutations in the sushi domains preventing protein interactions preclude axonal localization of GABAB1a. When fused to CD8α, the sushi domains polarize this uniformly distributed protein to axons. Likewise, when fused to mGluR1a the sushi domains redirect this somatodendritic protein to axons, showing that the sushi domains can override dendritic targeting information in a heterologous protein. Cell surface expression of the sushi domains is not required for axonal localization of GABAB1a. Altogether, our findings are consistent with the sushi domains functioning as axonal targeting signals by interacting with axonally bound proteins along intracellular sorting pathways. Our data provide a mechanistic explanation for the selective trafficking of GABAB(1a,2)receptors into axons while at the same time identifying a well defined axonal delivery module that can be used as an experimental tool.
Cell Type-Specific Long-Term Plasticity at Glutamatergic Synapses onto Hippocampal Interneurons Expressing either Parvalbumin or CB1Cannabinoid Receptor
Authors: Nissen Wiebke , Szabo Andras , Somogyi Jozsef , Somogyi Peter , Lamsa Karri P.
Published: January 2010

Different GABAergic interneuron types have specific roles in hippocampal function, and anatomical as well as physiological features vary greatly between interneuron classes. Long-term plasticity of interneurons has mostly been studied in unidentified GABAergic cells and is known to be very heterogeneous. Here we tested whether cell type-specific plasticity properties in distinct GABAergic interneuron types might underlie this heterogeneity. We show that long-term potentiation (LTP) and depression (LTD), two common forms of synaptic plasticity, are expressed in a highly cell type-specific manner at glutamatergic synapses onto hippocampal GABAergic neurons. Both LTP and LTD are generated in interneurons expressing parvalbumin (PV+), whereas interneurons with similar axon distributions but expressing cannabinoid receptor-1 show no lasting plasticity in response to the same protocol. In addition, LTP or LTD occurs in PV+ interneurons with different efferent target domains. Perisomatic-targeting PV+ basket and axo-axonic interneurons express LTP, whereas glutamatergic synapses onto PV+ bistratified cells display LTD. Both LTP and LTD are pathway specific, independent of NMDA receptors, and occur at synapses with calcium-permeable (CP) AMPA receptors. Plasticity in interneurons with CP-AMPA receptors strongly modulates disynaptic GABAergic transmission onto CA1 pyramidal cells. We propose that long-term plasticity adjusts the synaptic strength between pyramidal cells and interneurons in a cell type-specific manner and, in the defined CA1 interneurons, shifts the spatial pattern of inhibitory weight from pyramidal cell dendrites to the perisomatic region.
Background Light Produces a Recoverin-Dependent Modulation of Activated-Rhodopsin Lifetime in Mouse Rods
Authors: Chen Ching-Kang , Woodruff Michael L. , Chen Frank S. , Chen Desheng , Fain Gordon L.
Published: January 2010

The Ca2+-binding protein recoverin is thought to regulate rhodopsin kinase and to modulate the lifetime of the photoexcited state of rhodopsin (Rh*), the visual pigment of vertebrate rods. Recoverin has been postulated to inhibit the kinase in darkness, when Ca2+is high, and to be released from the disk membrane in light when Ca2+is low, accelerating rhodopsin phosphorylation and shortening the lifetime of Rh*. This proposal has remained controversial, in part because the normally rapid turnoff of Rh* has made Rh* modulation difficult to study in an intact rod. To circumvent this problem, we have made mice that underexpress rhodopsin kinase so that Rh* turnoff is rate limiting for the decay of the rod light response. We show that background light speeds the decay of Rh* turnoff, and that this no longer occurs in mice that have had recoverin knocked out. This is the first demonstration in an intact rod that light accelerates Rh* inactivation and that the Ca2+-binding protein recoverin may be required for the light-dependent modulation of Rh* lifetime.
Musical Training Induces Functional Plasticity in Human Hippocampus
Authors: Herdener Marcus , Esposito Fabrizio , di Salle Francesco , Boller Christian , Hilti Caroline C. , Habermeyer Benedikt , Scheffler Klaus , Wetzel Stephan , Seifritz Erich , Cattapan-Ludewig Katja
Published: January 2010

Training can change the functional and structural organization of the brain, and animal models demonstrate that the hippocampus formation is particularly susceptible to training-related neuroplasticity. In humans, however, direct evidence for functional plasticity of the adult hippocampus induced by training is still missing. Here, we used musicians' brains as a model to test for plastic capabilities of the adult human hippocampus. By using functional magnetic resonance imaging optimized for the investigation of auditory processing, we examined brain responses induced by temporal novelty in otherwise isochronous sound patterns in musicians and musical laypersons, since the hippocampus has been suggested previously to be crucially involved in various forms of novelty detection. In the first cross-sectional experiment, we identified enhanced neural responses to temporal novelty in the anterior left hippocampus of professional musicians, pointing to expertise-related differences in hippocampal processing. In the second experiment, we evaluated neural responses to acoustic temporal novelty in a longitudinal approach to disentangle training-related changes from predispositional factors. For this purpose, we examined an independent sample of music academy students before and after two semesters of intensive aural skills training. After this training period, hippocampal responses to temporal novelty in sounds were enhanced in musical students, and statistical interaction analysis of brain activity changes over time suggests training rather than predisposition effects. Thus, our results provide direct evidence for functional changes of the adult hippocampus in humans related to musical training.
Alleviating Transcriptional Inhibition of the NorepinephrineSlc6a2Transporter Gene in Depolarized Neurons
Authors: KN Harikrishnan , Bayles Richard , Ciccotosto Giuseppe D. , Maxwell Scott , Cappai Roberto , Pelka Gregory J. , Tam Patrick P. L. , Christodoulou John , El-Osta Assam
Published: January 2010

Recent studies have brought to light additional experimental information, namely, that the MeCP2 protein complex is not only capable of associating with members of the ATPase-dependent bromodomain family, but also found on nonmethylated genomic sequences. These unexpected results are indicative of a multifunctional role for MeCP2, more importantly; our view of the molecular mechanisms that regulate gene activity may not be necessarily distinguishable. Depolarized mouse neuronal cortical cells were examined for increasedSlc6a2mRNA synthesis, changes in CpG methylation status using bisulfite sequencing, and binding of MeCP2 and Smarca2 on theSlc6a2promoter sequence by chromatin immunopurification strategies. IncreasedSlc6a2gene expression in response to membrane depolarization was strongly correlated with the dissociation of MeCP2 and Smarca2 complex on the unmethylated gene. We identified that gene expression in neuronal cortical cells involves increased histone hyperacetylation on theSlc6a2promoter, which is commensurate with the recruitment of SP1 and RNA Polymerase II and is inversely correlated with H3K9 trimethylation. We hypothesize that the MeCP2 corepressor is capable of associating with multiple forms of SWI/SNF to remodel chromatin for important regulatory roles. The results of our experiments indicate that these proteins are asymmetrically bound to chromatin independent of DNA methylation and not inevitably diametrically opposed. These results now begin to offer a new perspective on the mechanism ofSlc6a2gene regulation.
Leptin Excites Proopiomelanocortin Neurons via Activation of TRPC Channels
Authors: Qiu Jian , Fang Yuan , Rønnekleiv Oline K. , Kelly Martin J.
Published: January 2010

Leptin can exert its potent appetite-suppressing effects via activation of hypothalamic proopiomelanocortin (POMC) neurons. It depolarizes POMC neurons via activation of a yet unidentified nonselective cation current. Therefore, we sought to identify the conductance activated by leptin using whole-cell recording in EGFP-POMC neurons from transgenic mice. The TRPC channel blockers SKF96365 (1-[β-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole hydrochloride), flufenamic acid, and 2-APB (2-aminoethyl diphenylborinate) potently inhibited the leptin-induced current. Also, lanthanum (La3+) and intracellular Ca2+potentiated the effects of leptin. Moreover, the diacylglycerol-permeable analog OAG (2-acetyl-1-oleoyl-sn-glycerol) failed to activate any TRPC current. Using a Cs+-gluconate-based internal solution, the leptin-activated current reversed near −20 mV. After replacement of external Na+and K+with Cs+, the reversal shifted to near 0 mV, and theI/Vcurve exhibited a negative slope conductance at voltages more negative than −40 mV. Based on scRT-PCR, TRPC1 and TRPC4–7 mRNA were expressed in POMC neurons, with TRPC5 being the most prevalent. The leptin-induced current was blocked by the Jak2 inhibitor AG490, the PI3 kinase inhibitor wortmannin, and the phospholipase C inhibitors, U73122 and ET-18-OCH3. Notably, we identified PLCγ1 transcripts in the majority of POMC neurons. Therefore, leptin through a Jak2–PI3 kinase–PLCγ pathway activates TRPC channels, and TRPC1, 4, and 5 appear to be the key channels mediating the depolarizing effects of leptin in POMC neurons.
A Network Centered on Ventral Premotor Cortex Exerts Both Facilitatory and Inhibitory Control over Primary Motor Cortex during Action Reprogramming
Authors: Buch Ethan R. , Mars Rogier B. , Boorman Erie D. , Rushworth Matthew F. S.
Published: January 2010

Ventral premotor cortex (PMv) is widely accepted to exert an important influence over primary motor cortex (M1) when hand movements are made. Although study of these interactions has typically focused on their excitatory nature, given its strong connections with both ventral and opercular frontal regions, one feature of the influence of PMv over M1 may be inhibitory. Paired-pulse transcranial magnetic stimulation (ppTMS) was used to examine functional interactions between human PMv and M1 during the selection and reprogramming of a naturalistic goal-directed action. One of two cylinders was illuminated on each trial. It was then grasped and picked up. On some trials, however, subjects had to reprogram the action as the illuminated cylinder was switched off and the other illuminated simultaneously with reach initiation. At a neurophysiological level, the PMv paired-pulse effect (PPE) on M1 corticospinal activity was facilitatory after the initial target presentation and during movement initiation. When reprogramming was required, however, the PPE became strongly inhibitory. This context-dependent change from facilitation to inhibition occurred within 75 ms of the change of target. Behaviorally, PMv-M1 ppTMS disrupted reprogramming. Diffusion-weighted magnetic resonance image scans were taken of each subject. Intersubject differences in the facilitation–inhibition contrast of PMv-M1 interactions were correlated with fractional anisotropy of white-matter in ventral prefrontal, premotor, and intraparietal brain areas. These results suggest that a network of brain areas centered on PMv inhibits M1 corticospinal activity associated with undesired movements when action plans change.
Contributions of Different Modes of TRPV1 Activation to TRPV1 Antagonist-Induced Hyperthermia
Authors: Garami Andras , Shimansky Yury P. , Pakai Eszter , Oliveira Daniela L. , Gavva Narender R. , Romanovsky Andrej A.
Published: January 2010

Transient receptor potential vanilloid-1 (TRPV1) antagonists are widely viewed as next-generation pain therapeutics. However, these compounds cause hyperthermia, a serious side effect. TRPV1 antagonists differentially block three modes of TRPV1 activation: by heat, protons, and chemical ligands (e.g., capsaicin). We asked what combination of potencies in these three modes of TRPV1 activation corresponds to the lowest potency of a TRPV1 antagonist to cause hyperthermia. We studied hyperthermic responses of rats, mice, and guinea pigs to eight TRPV1 antagonists with different pharmacological profiles and used mathematical modeling to find a relative contribution of the blockade of each activation mode to the development of hyperthermia. We found that the hyperthermic effect has the highest sensitivity to the extent of TRPV1 blockade in the proton mode (0.43 to 0.65) with no to moderate sensitivity in the capsaicin mode (−0.01 to 0.34) and no sensitivity in the heat mode (0.00 to 0.01). We conclude that hyperthermia-free TRPV1 antagonists do not block TRPV1 activation by protons, even if they are potent blockers of the heat mode, and that decreasing the potency to block the capsaicin mode may further decrease the potency to cause hyperthermia.
Shear band multiplication aided by free volume underthree-point bending
Authors: Zhang Lincai , Jiang Feng , Zhao Yanglei , Pan Shibin , He Lin , Sun Jun
Published: January 2010

Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass (BMG) alloy samples in both rod and plate geometry were prepared. Different free volume states were obtained through thermal treatment. The plastic deformation ability of the BMGs was investigated through both a three-point bending test and compression test. The three-point bending results reveal the important role of free volume content on the formation of multiple shear bands, as the shear band propagation can be efficiently stopped due to the existence of the stress gradient from the surface to the neutral plane. In compression, the sample size rather than free volume controls the shear banding behavior.
In situ observation of stress evolution in pure tin strip under electromigration using synchrotron radiation x-ray
Authors: Wu Albert T. , Siao Ciou-Nan , Ku Ching-Shun , Lee Hsin-Yi
Published: January 2010

This investigation elucidates stress evolution in situ in tin strips under electromigration using synchrotron radiation x-ray. Minute variations in stress are determined precisely using intense x-rays. Back stresses gradient with the values of 5.5 and 16.5 MPa/cm, which are induced by the current densities of 1 × 103and 5 × 103A/cm2, respectively, are measured directly. The effective diffusivities that include both grain and lattice diffusion at various current densities are determined. The Joule heating is observed, ranging from 5 to 15 °C, according to various current densities passed through the stripes. Results of this study suggest that the protective oxide layer on the surfaces significantly influences the kinetics of stress evolution.
Improving plasticity and toughness of Cu-Zr-Y-Al bulk metallic glasses via compositional tuning towards the CuZr
Authors: Shen Yong , Xu Jian
Published: January 2010

In this work, we propose a simple approach for designing plastic bulk metallic glasses (BMGs) by exploiting the ductility of intermetallic compounds involved in the BMG-forming system. Its validity was examined by investigating a series of quaternary Cu-Zr-Y-Al alloys along the composition tie-line between Cu42Zr44.4Y3.6Al10 (Y1) and the B2 CuZr phase, expressed as (Cu0.5Zr0.5)x(M)100-x (M = Zr0.15Y0.225Al0.625, 84≤x≤93). When tuning the composition towards the CuZr, the glass-forming ability of alloys is dramatically degraded, showing a reduction of critical diameter Dc for BMG formation from 16 mm at x = 84 (Y1) to 2 mm at x = 93. As the composition of BMGs shifts to the CuZr terminal, the shear modulus μ of the BMGs decreases, whereas the Poisson's ratio ν increases. With respect to the Y1 BMG, compressive plasticity and toughness of the Y2 BMG (x = 92, Dc = 4 mm) with a higher concentration of the CuZr are improved, which is consistent with its lower μ and higher ν values.
A study on materials interactions between Mo electrode and InGaZnO active layer in InGaZnO-based thin film transistors
Authors: Park Kyung , An Chee-Hong , Hwang Byung-Il , Lee Hoo-Jeong , Kim Hyoungsub , Son Kyungseok , Kwon Jang-Yeon , Lee Sangyun
Published: January 2010

This study examined the degradation of the device performance of InGaZnO4 (IGZO)-based thin-film transistors after annealing at high temperatures in air ambient. Using various characterization methods including scanning electron microscopy, x-ray diffraction, and transmission electron microscopy, we were able to disclose the details of a two-stage phase transformation that led to the device performance degradation. The Mo electrodes first succumbed to oxidation at moderate temperatures (400∼500 °C) and then the Mo oxide further reacted with IGZO to produce an In–Mo–O compound with some Ga at higher temperatures (600∼700 °C). We analyzed our results based on the thermodynamics and kinetics data available in the literature and confirmed that our findings are in agreement with the experimental results.
Sol-gel synthesis of cerium-doped yttrium silicates and their luminescent properties
Authors: Růžička Jakub , Nižňanský Daniel , Nikl Martin , Kucerková Romana , Cannas Carla
Published: January 2010

The Ce-doped yttrium ortho- and pyrosilicate powders were prepared in a powder form by the formamide-modified sol-gel method. Crystal structure was checked by x-ray diffraction and sample morphology by transmission electron microscopy measurements. Both ortho- and pyrosilicate pure phases were obtained by the previously mentioned preparation procedure and proper annealing temperature was determined to obtain the maximum scintillation efficiency. Luminescence spectra and decays were measured to better evaluate the source of efficiency losses in the scintillator mechanism of samples heat-treated at lower temperatures. The potential of this preparation method for manufacturing the nanocomposite scintillators was discussed.
Electrical characterization of epitaxial FeSi2 nanowire on Si (110) by conductive-atomic force microscopy
Authors: Liang Shengde , Ashcroft Brian A.
Published: January 2010

We used conductive-atomic force microscopy (c-AFM) for electrical characterization of self-assembled epitaxial iron silicide nanowires (NWs) on Si (110). The NWs, 6 nm high by 10 nm wide and several micrometers long, were partially covered by a macro-gold-pad as one electrode. Another electrode is the conductive AFM tip. The resistance of a single FeSi2 NW was measured to be 29.7 kΩ, corresponding to a resistivity of 150 ± 30 μΩ·cm. A Schottky barrier formed between NWs and silicon substrate was clearly demonstrated, which offers electrical isolation for NWs. An equivalent circuit model based on the Schottky barrier was proposed and was correlated with measurement results. This simple electrical characterization approach may find wide applications for various one-dimensional nanostructures.
Low temperature amorphization and superconductivity in FeSe single crystals at high pressures
Authors: Stemshorn Andrew K. , Tsoi Georgiy , Vohra Yogesh K. , Sinogeiken Stanislav , Wu Phillip M. , Huang Yilin , Rao Sistla M. , Wu Maw-Kuen , Yeh Kuo W. , Weir Samuel T.
Published: January 2010

In this study, we report low temperature x-ray diffraction studies combined with electrical resistance measurements on single crystals of iron-based layered superconductor FeSe to a temperature of 10 K and a pressure of 44 GPa. The low temperature high pressure x-ray diffraction studies were performed using a synchrotron source and superconductivity at high pressure was studied using designer diamond anvils. At ambient temperature, the FeSe sample shows a phase transformation from a PbO-type tetragonal phase to a NiAs-type hexagonal phase at 10 ± 2 GPa. On cooling, a structural distortion from a PbO-type tetragonal phase to an orthorhombic Cmma phase is observed below 100 K. At a low temperature of 10 K, compression of the orthorhombic Cmma phase results in a gradual transformation to an amorphous phase above 15 GPa. The transformation to the amorphous phase is completed by 40 GPa at 10 K. A loss of superconductivity is observed in the amorphous phase and a dramatic change in the temperature behavior of electrical resistance indicates formation of a semiconducting state at high pressures and low temperatures. The formation of the amorphous phase is attributed to a kinetic hindrance to the growth of a hexagonal NiAs phase under high pressures and low temperatures.
Investigation of grain boundaries for abnormal grain growth in polycrystalline SrTiO3
Authors: Shih Shao-Ju , Lozano-Perez Sergio , Cockayne David J.H.
Published: January 2010

Strontium titanate (SrTiO3) is widely used in electronic devices, and it is a model material for understanding the structural and dielectric properties of grain boundaries (GBs). In such materials, the GBs often play a dominant role in sintering and microstructural behavior. Abnormal grain growth (AGG) is a commonly observed phenomenon. Most studies explained that GBs contain continuous liquid films, and this liquid assists interface diffusion resulting in fast growth. However, few studies investigate the AGG behavior without any liquid. In this study, GB morphology and chemistry have been characterized by high-resolution transmission electron microscopy and x-ray energy-dispersive spectrometry, respectively. Different distributions of GB morphology have been observed in abnormal grains and matrix grains, and GB chemistry varies with different morphological type GBs. By correlating GB morphology and chemistry, a possible mechanism for AGG is proposed.
Transformation-induced plasticity in Fe–Cr–V–C
Authors: Kühn Uta , Romberg Jan , Mattern Norbert , Wendrock Horst , Eckert Jürgen
Published: January 2010

On the basis of the Fe84.3C4.6Cr4.3Mo4.6V2.2 high-speed tool steel, manufactured under relatively high cooling rates and highly pure conditions, a further improvement of the mechanical characteristics by slight modification of the alloy composition was attempted. For this, the alloy Fe88.9Cr4.3V2.2C4.6 was generated by elimination of Mo. By applying special preparation conditions, a microstructure composed of martensite, retained austenite, and a fine network of special carbides was obtained already in the as-cast state. This material exhibits extremely high compression strength of over 5000 MPa combined with large compression strain of more than 25% due to deformation-induced martensite formation. With this alloy a new composition of transformation-induced plasticity-assisted steels was found, which shows an extreme mechanical loading capacity.
Synthesis of single crystalline micron-sized rectangular silver bar
Authors: Mondal Biswajit , Majumdar Dipanwita , Saha Shyamal K.
Published: January 2010

The synthesis of single crystalline rectangular silver bar using polyacrylamide (PAM) and silver nitrate (AgNO3) by a hydrothermal process is reported. PAM has been used to create a reducing atmosphere as well as nucleation sites to produce silver seeds along the PAM chain. Several silver nanostructures viz. nanoparticles, growth of silver nanowires, and finally a single crystalline silver nanobar with a square cross section and of several microns in length, depending upon maturity and temperature of the hydrosol, are synthesized. At relatively lower temperatures (above 380 K) and higher pressure amide group of PAM is hydrolyzed with the liberation of ammonia (NH3), which produces a reducing atmosphere. As a result, the degraded PAM chain acts as nucleation sites to produce the assembly of silver nanocrystals along the chain. As the hydrosol becomes more and more mature, a directional growth of silver nanocrystals, called a mesocrystal, is formed. This mesocrystal is converted into single crystals due to fusion of higher energy surfaces (100) of nanocrystals to minimize the total surface energy. This growth process is completed with the formation of a single crystalline rectangular silver bar with a square cross section due to the growth of silver along the [110] direction.
A Practical Approach to Determine Permeability from Wireline Measurements
Authors: Al-Harbi Ahmed , Gringarten Alain , Akkurt Ridvan
Published: January 2010

Permeability is a crucial input to any simulation effort to forecast production. It is available from different sources: core, nuclear magnetic resonance (NMR), wireline formation tester (WFT) and drill stem test (DST). These sources are different in many aspects: the type of permeability they measure, e.g. absolute or effective, the scale of measurement in the vertical and the lateral directions and the degree of inconvenience caused by the data acquisition process in terms of operational constraints, costs, safety issues, etc.

Much effort has been invested by the industry to be able to use the most cost effective tools, NMR and WFT, for permeability measurement as substitute for the less convenient ones: core and DST. Results of these efforts are still mostly qualitative.

This work is a summary of the senior author's MSc thesis1 which reviewed the different sources of permeability and their limitations using field data from, an oil bearing, clastic reservoir that included core, NMR, WFT and DST. All these data were analyzed and interpreted for permeability evaluation. The objective of the study was to develop an approach for calibrating the static NMR permeability log with the WFT dynamic data and to compare the results with the traditional approach of calibrating with cores. Permeabilities from both approaches were upscaled for comparing with DST-derived permeabilities.

It was found that the upscaled WFT-calibrated NMR permeabilities match the DST permeabilities as satisfactorily as the upscaled core-calibrated NMR permeabilities.
Demography of Unexploited Beavers in Southern Illinois
Authors: BLOOMQUIST CRAIG K. , NIELSEN CLAYTON K.
Published: January 2010

ABSTRACT Beavers (Castor canadensis) are important in ecosystems and to humans. Although beavers are increasingly protected from harvest, relatively few studies of unexploited beaver populations have been reported. Furthermore, few radiotelemetry studies exist for beavers because no practical method of attaching a radiotransmitter to beavers was available until recently. We used radiotelemetry, remote videography, and trapping data to quantify survival, dispersal, and natality of unexploited beavers in southern Illinois, USA, during 2004 to 2006. Beaver colony density was one of the highest reported in the wildlife literature at 3.27 colonies/km2. We monitored 62 beavers for survival; all mortalities (n = 15) occurred during the fall and winter seasons. The pooled annual survival rate for adult and juvenile females was (x̄±SE) 0.76±0.05. Annual survival rates for adult and juvenile males were 0.87±0.04 and 0.55±0.07, respectively. Seasonal survival only differed among sex classes and age classes during the fall. Dispersal rates for juvenile beavers ranged from 0.38±0.13 to 0.59±0.13 and did not vary by sex or age. To quantify natality and recruitment, we captured and euthanized 79 beavers adjacent to our live‐capture area; we found a low pregnancy rate of adult females (36%), and no juveniles were bred. Natality of bred females was 3.6 offspring per adult female, and 0.36 kits were recruited per adult female. Apparent kit survival was 28%. Our research provides information to wildlife managers about beaver demographics for a high‐density population, based on relatively large sample sizes and novel research techniques for the species.
A Conservation Institution for the 21st Century: Implications for State Wildlife Agencies
Authors: JACOBSON CYNTHIA A. , ORGAN JOHN F. , DECKER DANIEL J. , BATCHELLER GORDON R. , CARPENTER LEN
Published: January 2010

ABSTRACT  The wildlife conservation institution (Institution) needs to reform to maintain legitimacy and relevancy in the 21st century. Institutional reform is inherently slow. Limitations resulting from historical and resource dependencies between state wildlife agencies and hunters have left the Institution poorly positioned to meet changing ecological and social complexities. In this paper, we suggest that an ideal Institution would have the following 4 components: broad‐based funding, trustee‐based governance, multidisciplinary science as the basis of recommendations from professional staff, and involvement of diverse stakeholders and partners. Our suggestions reflect the fundamental tenets of the Public Trust Doctrine, which we believe is the foundation of the Institution. In bringing forth these ideas, we hope to encourage discussion about how the Institution should reform to meet the changing needs of society.
Barred Owl Space Use and Habitat Selection in the Eastern Cascades, Washington
Authors: SINGLETON PETER H. , LEHMKUHL JOHN F. , GAINES WILLIAM L. , GRAHAM SCOTT A.
Published: January 2010

ABSTRACT  Competition with barred owls (Strix varia varia) is an important factor contributing to the continued decline of threatened northern spotted owl (Strix occidentalis caurina) populations in the Pacific Northwest, USA, but basic information on habitat selection and space use patterns of barred owls is lacking for much of the region. We investigated space use and habitat selection by tracking radiotagged barred owls in the Eastern Cascade Range of Washington, USA, from 2004 to 2006. We surveyed for barred owls across the 309‐km2 study area and confirmed presence of barred owl pairs at 21 sites. We collected movement data on 14 barred owls from 12 sites. Mean annual 95% fixed‐kernel home‐range size was 194 ha for females (n = 4, SD = 70) and 288 ha for males (n = 5, SD = 114). Home ranges were located more frequently than expected in areas with low topographic position, gentle slopes, large overstory tree‐crown diameter, high normalized difference vegetation index (NDVI), overstory tree canopy closure >72%, and a moderate amount of solar insolation. Within home ranges, areas that had large tree‐crown diameters, low topographic positions, and gentle slopes were used more frequently than expected. The resource selection function we developed for barred owls in our study area indicated that barred owls used areas with the combination of low values for topographic position and slope and higher values for NDVI, solar insolation, and an interaction term for canopy closure and tree‐crown diameter. In comparison to published information on northern spotted owls, barred owls used areas with similar canopy closure and tree size classes, but barred owl home ranges were much smaller and more concentrated on gentler slopes in valley bottoms. This information may contribute to the development of management practices that maintain forest characteristics appropriate for spotted owl habitat and prey in areas where spotted owls are least likely to be excluded by territorial barred owls in the Eastern Cascades of Washington.
From Wiens to Robel: A Review of Grassland‐Bird Habitat Selection
Authors: FISHER RYAN J. , DAVIS STEPHEN K.
Published: January 2010

ABSTRACT  Efforts to stabilize or increase grassland bird populations require identification of suitable habitat as a first step. Although the number of studies examining grassland‐bird habitat selection has increased substantially in recent years, much uncertainty exists regarding local‐scale habitat variables that researchers should consider. We reviewed 57 studies and identified important vegetation features correlated with grassland bird abundance, density, occurrence, and nest and territory selection. Our objectives were to 1) guide future studies of grassland‐bird habitat use by providing a reduced set of relevant vegetation characteristics, 2) challenge researchers to critically think about what variables to consider, and 3) highlight the need to include consistent definitions of terms used to describe grassland bird habitat. We identified 9 variables that were important predictors of habitat use by grassland birds: coverage of bare ground (important in 50% of the instances where it was included), grass (34% of instances), dead vegetation (33% of instances), forbs (31% of instances), and litter (29% of instances), along with an index of vegetation density (39% of instances) and volume (39% of instances), litter depth (36% of instances), and vegetation height (41% of instances). Only 25% of studies provided information on effects sizes and measures of variance. Furthermore, definitions of measured habitat variables were not consistent among studies. We provide definitions of the 9 important variables and implore authors to report effect size and measures of variance. Standardization of terms and reporting of meaningful results will facilitate replication of wildlife research and enhance our ability to recognize general patterns that emerge from observational studies of habitat use.
Winter Distribution, Movements, and Annual Survival of Radiomarked Vancouver Canada Geese in Southeast Alaska
Authors: HUPP JERRY W. , HODGES JOHN I. , CONANT BRUCE P. , MEIXELL BRANDT W. , GROVES DEBBIE J.
Published: January 2010

ABSTRACT  Management of Pacific Flyway Canada geese (Branta canadensis) requires information on winter distribution of different populations. Recoveries of tarsus bands from Vancouver Canada geese (B. canadensis fulva) marked in southeast Alaska, USA, ≥4 decades ago suggested that ≥83% of the population was non‐migratory and that annual adult survival was high (Ŝ = 0.836). However, recovery distribution of tarsus bands was potentially biased due to geographic differences in harvest intensity in the Pacific Flyway. Also, winter distribution of Vancouver Canada geese could have shifted since the 1960s, as has occurred for some other populations of Canada geese. Because winter distribution and annual survival of this population had not recently been evaluated, we surgically implanted very high frequency radiotransmitters in 166 adult female Canada geese in southeast Alaska. We captured Vancouver Canada geese during molt at 2 sites where adults with goslings were present (breeding areas) and 2 sites where we observed nonbreeding birds only. During winter radiotracking flights in southeast Alaska, we detected 98% of 85 females marked at breeding areas and 83% of 70 females marked at nonbreeding sites, excluding 11 females that died prior to the onset of winter radiotracking. We detected no radiomarked females in coastal British Columbia, or western Washington and Oregon, USA. Most (70%) females moved ≤30 km between November and March. Our model‐averaged estimate of annual survival (Ŝ = 0.844, SE = 0.050) was similar to the estimate of annual survival of geese marked from 1956 to 1960. Likely <2% of Vancouver Canada geese that nest in southeast Alaska migrate to winter areas in Oregon or Washington where they could intermix with Canada geese from other populations in the Pacific Flyway. Because annual survival of adult Vancouver Canada geese was high and showed evidence of long‐term consistency, managers should examine how reproductive success and recruitment may affect the population.
The Effects of Winter Burning and Grazing on Resources and Survival of Texas Horned Lizards in a Thornscrub Ecosystem
Authors: HELLGREN ERIC C. , BURROW ANNA L. , KAZMAIER RICHARD T. , RUTHVEN DONALD C.
Published: January 2010

ABSTRACT The ecological effects of land‐use practices on reptiles, especially endangered or threatened species, are of conservation and scientific interest. We describe the effects of rotational livestock grazing and prescribed winter burning on resources and survival of the Texas horned lizard (Phrynosoma cornutum) during the summers of 1998 to 2001 in southern Texas, USA. We evaluated survival rates of Texas horned lizards (n= 111) on 6 study sites encompassing 5 different burning and grazing treatments. We also measured indices of cover (i.e., vegetation) and food abundance (i.e., harvester ants [Pogonomyrmex rugosus]). We telemetered and relocated adult lizards daily. We divided the study into 2 seasons, spring (15 Apr–30 Jun) and summer (1 Jul–15 Aug), corresponding to the relative activity of horned lizards. Winter burning provided an increase in food resources and led to increased survival of Texas horned lizards in the second growing season after fire, but grazing‐induced changes in vegetation cover reduced survival, likely by increasing lizard vulnerability. Fire and grazing reduced litter and increased bare ground and forb cover but did not affect woody vegetation. Ant activity was greater in burned sites and varied with grazing level, season, and year. Summer survival functions of horned lizards varied by burning treatment, with higher survival observed on burned sites in the second year after burning. Survival rates were ordered from highest in ungrazed sites to lowest in heavily grazed sites. We recognize the limitations of our work resulting from a lack of spatial replication of treatments. However, our mensurative study provides fertile ground for future hypothesis testing regarding the effects of land management on shrubland and grassland reptiles. We propose that future studies focus on the population consequences of variation in burn frequency, burn timing, and grazing intensity.
Comparative Space Use and Habitat Selection of Moose Around Feeding Stations
Authors: VAN BEEST FLORIS M. , LOE LEIF EGIL , MYSTERUD ATLE , MILNER JOS M.
Published: January 2010

ABSTRACT The practice of feeding cervids in winter, either as a supplement to enhance nutritional status or to divert animals away from roads, railways, or vulnerable habitats, is rising noticeably. Moose (Alces alces) densities in Scandinavia are currently at historically high levels, resulting in amplified damage to economically important young Scots pine (Pinus sylvestris) forest stands. Nevertheless, there is limited information as to how diversionary feeding affects herbivore space use and habitat selection. We followed 32 female moose marked with Global Positioning System collars to evaluate 1) if feeding stations serve as attraction points to the extent that habitat‐selection patterns resemble those of central‐place foragers (i.e., high usage and more uniform selection close to the attraction point), and 2) if moose using feeding sites select young pine stands less than those not using feeding sites. Moose that used diversionary forage concentrated their space use around feeding stations and selected habitats as predicted for a central‐place forager with a decreasing probability of using areas away from feeding sites and a low degree of habitat selectivity close to feeding sites. However, moose that used feeding sites continued to select young pine stands to the same extent as moose that did not use feeding sites. Feeding sites were, therefore, not successful in diverting moose away from valuable natural browse, so we recommend wildlife managers establish feeding sites in sacrifice areas where moose browsing is permissible and, if possible, >1 km from young pine plantations.
Ground Roost Resource Selection for Merriam's Wild Turkeys
Authors: LEHMAN CHAD P. , THOMPSON DANIEL J. , RUMBLE MARK A.
Published: January 2010

ABSTRACT  Concealment cover is important for ground‐roosting wild turkey (Meleagris gallopavo) poults immediately following hatch during the vulnerable, preflight stage. We compared concealment cover resources selected at ground roosts to those of nest sites and available resources for Merriam's turkeys (Meleagris gallopavo merriami) in the Black Hills of South Dakota, USA. Females with preflight poults selected ground roosts that were similar in structure to nest sites. Ground roosts and nests were greater in visual obstruction (unit odds ratios ≥1.19) than random sites. However, ground roosts were closer to meadow‐forest edges than either nests or random sites (unit odds ratios ≤0.98). Structure at ground roosts may provide visual protection from predators, and management for shrub vegetation or woody debris along meadow‐pine forest ecotones will provide cover for Merriam's turkey broods.
Bioenergy II: Modeling and Multi-Objective Optimization of Different Biodiesel Production Processes
Authors: Di Nicola Giovanni , Moglie Matteo , Pacetti Marco , Santori Giulio
Published: January 2010

One of the most promising renewable fuels proposed as an alternative to fossil fuels is biodiesel. The competitive potential of biodiesel is limited by the price of vegetable oils, which strongly influences the final price of biofuels. An appropriate planning and design of the whole production process, from the seed to the biodiesel end product, is essential in order to contain the fallout of energy inefficiencies in the high price of the end product. This study focuses on the characteristics of the production process currently used to produce biodiesel.Refined vegetable oil can be converted into biodiesel by means of a great variety of techniques and technologies, many of which are still not suitable for application on an industrial scale. The solution of greatest interest is homogeneous alkaline transesterification with KOH and methanol. Even when dealing with this type of conversion, it is impossible to establish a universal pattern to describe the conversion or purification stages because there are various possible solutions that make each system different from another. When we look more closely at the state of the art in industrial biodiesel production plants, we also encounter the potential problems introduced by the type and characteristics of the raw materials.Comparing some of the reference solutions that have inspired numerous installations, an optimization analysis was conducted using ASPENPLUS 2006, for the modeling of the process, and modeFRONTIER 4.1 for the optimization procedure. The optimization analysis was carried out using a multi-objective genetic algorithm optimization in order to define the configuration of the main parameters that guarantee the best trade-off between the maximization of the purity of some important compounds and the minimization of energy requirements in the process. The results of this analysis were Pareto frontiers that identify a family of configurations which define the best trade-off between the objectives. Using the Pareto frontiers we then selected the configuration that requires the minimum energy consumption. Among these optimal configurations there is one which guarantees the lowest specific energy consumption while all the optimal configurations obtained respected the requirements of EN 14214, in terms of biodiesel quality.
Optimization studies on Biosorption of Copper (II) by Crab Shell Using Response Surface Methodology(RSM)
Authors: S Sudesh , M Meenakshi , R.Y Sheeja , Murugesan Thanapalan
Published: January 2010

In the present work, crab shell was used as the biosorbent to remove copper from aqueous solution. Batch experiments were performed at different initial copper concentration of copper solutions (1-40 g/l), initial pH (2-9), temperature (20-400°C), and biosorbent dosages (2-10 g/l). The maximum removal of copper using crab shell occurred at a pH of 3 and at a temperature of 400°C using an optimum biosorbent dosage of 5 g/l. A mathematical model was proposed to identify the effects of the individual interactions of these variables on the biosorption of copper. The results have been modeled using response surface methodology using a Box-Behnken design. The response surface method was developed using three levels (-1, 0, +1) with the above mentioned four factors. The second order quadratic regression model fitted the experimental data with Prob > F to be < 0.0001. The experimental values were found to be in good agreement with the predicted values, with a satisfactory correlation coefficient of R2 = 0.9999.
Variability of pathogenicity of Fusarium spp. originating from maize and wheat grains
Authors: Tancic Sonja , Stankovic Slavica , Levic Jelena
Published: January 2010

Differences in the pathogenicity of 93 isolates of seven species belonging to the genus Fusarium (F. graminearum, F. verticillioides, F. proliferatum, F. subglutinans, F. sporotrichioides, F. semitectum and F. equiseti), originating from maize kernels (61) and wheat grains (32), were examined based on the germination percentage of inoculated seeds. The studied species demonstrated inter- and intraspecies variability regarding the effects on maize seed germination. On the average, the greatest germination reduction was found in seeds inoculated with the spore suspensions of F. sporotrichioides and F. graminearum. A similar reduction was detected in seeds inoculated with F. proliferatum and F. subglutinans. The effect of F. subglutinans on seed germination reduction was higher compared to the two latter species, while the effects of F. semitectum and F. equiseti were smallest. The majority of isolates were of moderate pathogenicity, while the lowest number of isolates was either very pathogenic (7) or apathogenic (10). Pathogenicity of the isolates originating from wheat grains was generally lower than the pathogenicity of isolates originating from maize kernels, with the exception of F. sporotrichioides.
Biological variability of zucchini yellow mosaic virus in Serbia
Authors: Vucurovic Ana , Bulajic Aleksandra , Djekic Ivana , Ristic Danijela , Berenji Janos , Krstic Branka
Published: January 2010

Zucchini yellow mosaic virus (ZYMV) has become an important pathogen of cucurbits over the past 20 years. In our country, this virus also causes significant losses, especially in oil pumpkin production. Although ZYMV variability has been extensively studied worldwide by biological and molecular characterization, such information is still limited for the European region. Herein, we present the first analysis of phenotypic variations of ZYMV isolates sampled from oil pumpkin cv. Olinka from different locations in Serbia during 2008. Twelve isolates were obtained by mechanical inoculation on the C. pepo hybrid Ezra F1, and four of them were chosen for further detailed biological study. These investigated isolates exhibited different phenotypical features and thus represented different variants, concerning their host range, and type and severity of symptoms. A previously developed primer pair, ZYMV CPfwd/CPrev, was tested to determine its suitability for detection of Serbian ZYMV isolates. Amplification of Serbian ZYMV isolates of different origin, in single and mixed infection, resulted in one distinctive band. The used primer pair proved to be useful not only for routine molecular detection, but also for further molecular characterization of Serbian ZYMV isolates because it amplifies the hypervariable genomic region of ZYMV. The result obtained in this study is a contribution to investigation of genetic diversity of Serbian ZYMV isolates and their molecular relationship with ZYMV isolates from other parts of the world.