bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of Expected Value on Saccadic Preparation
Authors: Milstein David M. , Dorris Michael C.
Published: May 2007

Basing higher-order decisions on expected value (reward probability × reward magnitude) maximizes an agent's accruement of reward over time. The goal of this study was to determine whether the advanced preparation of simple actions reflected the expected value of the potential outcomes. Human subjects were required to direct a saccadic eye movement to a visual target that was presented either to the left or right of a central fixation point on each trial. Expected value was manipulated by adjusting the probability of presenting each target and their associated magnitude of monetary reward across 15 blocks of trials. We found that saccadic reaction times (SRTs) were negatively correlated to the relative expected value of the targets. Occasionally, an irrelevant visual distractor was presented before the target to probe the spatial allocation of saccadic preparation. Distractor-directed errors (oculomotor captures) varied as a function of the relative expected value of, and the distance of distractors from, the potential valued targets. SRTs and oculomotor captures were better correlated to the relative expected value of actions than to reward probability, reward magnitude, or overall motivation. Together, our results suggest that the level and spatial distribution of competitive dynamic neural fields representing saccadic preparation reflect the relative expected value of the potential actions.
Sensorimotor Gating in Larval Zebrafish
Authors: Burgess Harold A. , Granato Michael
Published: May 2007

Control of behavior in the natural environment where sensory stimuli are abundant requires superfluous information to be ignored. In part, this is achieved through selective transmission, or gating of signals to motor systems. A quantitative and clinically important measure of sensorimotor gating is prepulse inhibition (PPI) of the startle response, impairments in which have been demonstrated in several neuropsychiatric disorders, including schizophrenia. Here, we show for the first time that the acoustic startle response in zebrafish larvae is modulated by weak prepulses in a manner similar to mammalian PPI. We demonstrate that, like in mammals, antipsychotic drugs can suppress disruptions in zebrafish PPI induced by dopamine agonists. Because genetic factors underlying PPI are not well understood, we performed a screen and isolated mutant lines with reduced PPI. Analysis ofOpheliamutants demonstrates that they have normal sensory acuity and startle performance, but reduced PPI, suggesting thatOpheliais critical for central processing of sensory information. Thus, our results provide the first evidence for sensorimotor gating in larval zebrafish and report on the first unbiased screen to identify genes regulating this process.
Lbx1 Acts as a Selector Gene in the Fate Determination of Somatosensory and Viscerosensory Relay Neurons in the Hindbrain
Authors: Sieber Martin A. , Storm Robert , Martinez-de-la-Torre Margaret , Müller Thomas , Wende Hagen , Reuter Katja , Vasyutina Elena , Birchmeier Carmen
Published: May 2007

Distinct types of relay neurons in the hindbrain process somatosensory or viscerosensory information. How neurons choose between these two fates is unclear. We show here that the homeobox geneLbx1is essential for imposing a somatosensory fate on relay neurons in the hindbrain. InLbx1mutant mice, viscerosensory relay neurons are specified at the expense of somatosensory relay neurons. Thus Lbx1 expression distinguishes between the somatosensory or viscerosensory fate of relay neurons.
Cannabinoids Excite Hypothalamic Melanin-Concentrating Hormone But Inhibit Hypocretin/Orexin Neurons: Implications for Cannabinoid Actions on Food Intake and Cognitive Arousal
Authors: Huang Hao , Acuna-Goycolea Claudio , Li Ying , Cheng H. M. , Obrietan Karl , van den Pol Anthony N.
Published: May 2007

Cannabinoids modulate energy homeostasis and decrease cognitive arousal, possibly by acting on hypothalamic neurons including those that synthesize melanin-concentrating hormone (MCH) or hypocretin/orexin. Using patch-clamp recordings, we compared the actions of cannabinoid agonists and antagonists on identified MCH or hypocretin neurons in green fluorescent protein-expressing transgenic mice. The cannabinoid type-1 receptor (CB1R) agonistR-(+)-[2,3-dihydro-5-methyl-3-(4-morpho linylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-naphthalenylmethanone mesylate (WIN55,212,2) depolarized MCH cells and increased spike frequency; in contrast, WIN55,212,2 hyperpolarized and reduced spontaneous firing of the neighboring hypocretin cells, both results consistent with reduced activity seen with intracerebral cannabinoid infusions. These effects were prevented by AM251 [N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide], a CB1R antagonist, and by tetrodotoxin, suggesting no postsynaptic effect on either neuron type. In MCH cells, depolarizing WIN55,212,2 actions were abolished by the GABAAreceptor antagonist bicuculline, suggesting that the CB1R-mediated depolarization was attributable to reduced synaptic GABA release. WIN55,212,2 decreased spontaneous IPSCs, reduced the frequency but not amplitude of miniature IPSCs, and reduced electrically evoked synaptic currents in MCH cells. Glutamate microdrop experiments suggest that WIN55,212,2 acted on axons arising from lateral hypothalamus local inhibitory cells that innervate MCH neurons. In hypocretin neurons, the reduced spike frequency induced by WIN55,212,2 was attributable to presynaptic attenuation of glutamate release; CB1R agonists depressed spontaneous and evoked glutamatergic currents and reduced the frequency of miniature EPSCs. Cannabinoid actions on hypocretin neurons were abolished by ionotropic glutamate receptor antagonists. Together, these results show that cannabinoids have opposite effects on MCH and hypocretin neurons. These opposing actions could help explain the increase in feeding and reduction in arousal induced by cannabinoids.
The Effect of Angioscotomas on Map Structure in Primary Visual Cortex
Authors: Giacomantonio Clare E. , Goodhill Geoffrey J.
Published: May 2007

When blood vessels occlude the photoreceptor layer in the retina, they cast shadows onto the photoreceptors, creating angioscotomas (regions of the visual field to which that eye is blind). Remarkably, Adams and Horton (2002) have recently shown that it is sometimes possible to observe representations of these angioscotomas anatomically in the primary visual cortices of squirrel monkeys. However, there is substantial variability in the degree and form of these representations. The source of this variability is difficult to determine experimentally, because experimental studies are unavoidably limited by small sample size. In addition, experimental studies cannot compare the map structure that would develop with and without an angioscotoma. Here, we investigate these phenomena computationally using feature-mapping models of visual cortical development, which are not subject to the same limitations. These models suggest that the primary source of variability in angioscotoma representation is the precise timing of the onset of visual experience relative to the time course of ocular dominance column segregation. Furthermore, the models predict that angioscotomas could compete for control of local column layout with other influences such as cortical shape but that they have a small effect on the structure of orientation preference maps.
Spectrotemporal Receptive Fields in the Inferior Colliculus Revealing Selectivity for Spectral Motion in Conspecific Vocalizations
Authors: Andoni Sari , Li Na , Pollak George D.
Published: May 2007

Frequency modulations are a prominent feature of animal vocalizations and human speech. Here we investigated how neurons in the inferior colliculus (IC) of Mexican free-tailed bats respond to the frequency-modulated (FM) direction and velocity of complex signals by extracting their spectrotemporal receptive fields (STRFs) using a family of upward- and downward-moving ripple stimuli. STRFs were obtained in more than half of the cells that were sampled. To verify the validity of each STRF, we compared their features both with tone-evoked responses and by convolving the STRF with several conspecific calls. We show that responses to tones are in close agreement with the STRF and that the responses predicted by convolutions compare favorably with responses evoked by those calls. The high predictability showed that the STRF captured most of the excitatory and inhibitory properties of IC cells. Most neurons were selective for the direction and velocity of spectral motion with a majority favoring the downward FM direction, and most had spectrum–time inseparability that correlated with their direction selectivity. Furthermore, blocking inhibition significantly reduced the directional selectivity of these neurons, suggesting that inhibition shapes FM direction selectivity in the IC. Finally, we decomposed the natural calls into their ripple components and show that most species-specific calls have downward-sweeping FM components with sweep velocities that correspond with the preferred sweep velocities of IC neurons. This close quantitative correspondence among features of signals and responses suggests that IC cells are tuned by inhibition to respond optimally to spectral motion cues present in their conspecific vocalizations.
The Tyrosine Kinase Fyn Determines the Localization of TrkB Receptors in Lipid Rafts
Authors: Pereira Daniela B. , Chao Moses V.
Published: May 2007

Localization of Trk neurotrophin receptors is an important factor in directing cellular communication in developing and mature neurons. One potential site of action is in lipid raft membrane microdomains. Although Trk receptors have been localized to lipid rafts, little is known about how these neurotrophin receptors are directed there or how localization to these membrane microdomains regulates Trk signaling. Here, we report that the TrkB brain-derived neurotrophic factor (BDNF) receptor specifically localized to intracellular lipid rafts in cortical and hippocampal membranes in response to BDNF and that this process was critically dependent on the tyrosine kinase Fyn. BDNF-induced TrkB accumulation at lipid rafts was prevented by blocking the internalization of TrkB. BDNF stimulation also resulted in the association between endogenous TrkB and Fyn. Moreover, in neurons derived from Fyn knock-out mice, the translocation of TrkB to lipid rafts in response to BDNF was compromised, whereas the corticohippocampal region of Fyn mutants displayed lower amounts of TrkB in lipid raftsin vivo. In support of a role for lipid rafts in neurotrophin signaling, inhibiting TrkB translocation to lipid rafts, either by using Fyn knock-out neurons or lipid raft-disturbing agents, prevented the full activation of TrkB and of downstream phospholipase C-γ. These results indicate that the lipid raft localization of TrkB receptors is regulated by Fyn and represents an important factor in determining the outcome of BDNF signaling in neurons.
Book Reviews
Authors: Grant Anthony P.
Published: May 2007

Contact Englishes of the Eastern Caribbean. Michael Aceto and Jeffrey P. Williams, eds. Amsterdam: John Benjamins. (Varieties of English around the World, G30), 2003. xx. 320 pp.
Language and Social Identity
Authors: Pomerantz Anne
Published: May 2007

Language and Social Identity. Richard K. Blot, ed. Westport, CT: Praeger Publishers, 2003. 295 pp.

Identity in Narrative:. Study of Immigrant Discourse. Anna De Fina. Amsterdam: John Benjamins, 2003. 251 pp.

Negotiation of Identities in Multilingual Contexts. Aneta Pavlenko and Adrian Blackledge, eds.Clevedon, UK: Multilingual Matters, 2004. 349 pp.
Gender and Politeness
Authors: Quinn E. Moore
Published: May 2007

Gender and Politeness. Sara Mills. Cambridge: Cambridge University Press, 2003. viii. 270 pp.
From Ritual to Art: The Aesthetics and Cultural Relevance of Igbo Satire
Authors: Simpson Paul
Published: May 2007

From Ritual to Art: The Aesthetics and Cultural Relevance of Igbo Satire. Christine Nwakego. Ohale. Lanham, MD: University Press of America, 2003. x. 180 pp.
Respecting the Language of Elders: Ideological Shift and Linguistic Discontinuity in a Northern Athapascan Community
Authors: Meek Barbra A.
Published: May 2007

This article examines an ideological shift related to and affecting language shift, focusing especially on children's experiences. I show that while elders retained their status as intellectual authorities responsible for passing their knowledge on to younger community members, their knowledge became limited to practices conceptualized as "traditionally Kaska," of which language was an integral part. As a result, the acquisition of Kaska became subject to the same social practices that organized other forms of "traditional indigenous" or specialized knowledge such that speaking Kaska became the domain of elders. Children's and youth's commentary and practices articulated and solidified this ideological transformation.
Arapaho Imperatives: Indirectness, Politeness and Communal "Face"
Authors: Cowell Andrew
Published: May 2007

This article first provides a description of the imperative verb order in Arapaho, which has never been fully described. It then examines the use of indirect imperatives in particular, which grammaticalize the roles of third parties, as well as speakers and addressees. Close attention is paid to the interplay between prototypical reference‐world situations, questions of socially‐determined authority and relationships, and the issue of deference and politeness more generally. This discussion is placed in the context of Arapaho society, where traditional ceremonial roles, stereotyped kinship relationships, and an age‐graded hierarchy remain important among older Arapaho speakers. The article concludes with a consideration of the concept of communal "face" as a revision to excessively individualistic analyses of politeness.
Desire, Youth, and Realism in Tamil Cinema
Authors: Nakassis Constantine V. , Dean Melanie A.
Published: May 2007

This article first examines representations of women's desire in Tamil cinema, from highly implicit and non‐transgressive representations of desire in an older movie to linguistically explicit and transgressive representations of desire in a recent hit movie. We then examine how such contemporary filmic representations are related to what we call a mode of realist spectatorship, and how this mode of spectatorship is linked to a particular social group (male youth) and to film form. We argue that the emergence of this mode of spectatorship, the films associated with it, and their connection to male youth are due to changes in the film market and to differential socialization by generation. Finally, we argue for realism in film as holding when film form and spectatorship are highly calibrated in the following way: some set of filmic representations are evaluated by viewers and filmmakers through culturally mediated classifications of "real" and "unreal" which are operationalized truth‐functionally in events of evaluation; such representations presuppose these classifications, and by virtue of regular presupposition can entail an experience of "reality" for viewers.
Simultaneous detection of three porcine viruses by multiplex PCR
Authors: Sámi L. , Ursu Krisztina , McKillen J. , Kecskeméti S. , Belák S. , Kiss I.
Published: May 2007

Specific oligonucleotide primers were selected and combined in a multiplex arrangement, in order to detect simultaneously three economically important porcine viruses by polymerase chain reaction (PCR). The pathogen panel was comprised of viruses that cause reproductive failure in infected herds: Aujeszky’s disease virus (ADV), porcine parvovirus (PPV) and porcine respiratory and reproductive syndrome virus (PRRSV). In order to reduce the time required for the detection of the pathogens, the assay was optimised to a RapidCycler PCR instrument. The multiplex PCR assay was shown to be specific, sensitive and rapid, because the results were read in less than 60 min after sample preparation. Due to its speed, efficiency and sensitivity, the described rapid multiplex PCR assay serves as a useful novel tool in the veterinary diagnostic laboratories for the quick and complex detection of these important porcine pathogens.
Isolation and development of haematopoietic progenitor cells from peripheral blood of adult and newborn pigs
Authors: Gómez-Ochoa P. , Miana-Mena F. , Muñoz M. , Gascón M. , Castillo J. , Cativiela E. , Gómez F.
Published: May 2007

Pluripotent stem cells (PSCs), already described in human beings, are fibroblast-like cells that exhibit a CD34 marker specific for haematopoietic stem cells. In this work we have demonstrated the presence of PSCs in the peripheral blood of pigs, a species frequently used in transplantation studies as an animal model for human diseases. Differentiation into haematopoietic colonies (granulomacrophagic colonies, erythroid colonies and mixed colonies) has been carried out with the peripheral blood of adult and newborn pigs, using solely human commercial media. Peripheral blood mononuclear cells (PBMNCs) were cultured in semisolid methylcellulose based media enriched with recombinant human cytokines, achieving granulomacrophagic-colony forming unit (GM-CFU) and mixed-colony forming unit (Mix-CFU) growth with erythroblastic lineage proliferation in the presence of erythropoietin (Epo). In all the samples CFU growth was associated with the presence of recombinant human cytokine. No evidence of proliferation in control plates without cytokines was found. From liquid medium culture, a population of macrophages and CD34+ fibroblast like cells were retrieved 21 days after sowing. These findings allow us to think about the direct application of this simple and standardised method in several work fields such as the study of pharmacological effects of many drugs over the haematopoietic line and in the study of new strategies in cellular therapy for some human diseases.
Effects of fasting and refeeding on the antioxidant system in cockerels and pullets
Authors: Milinković-Tur Suzana , Stojević Z. , Piršljin Jasna , Zdelar-Tuk Maja , Poljičak-Milas Nina , Ljubić Blanka , Gradinski-Vrbanac Bojana
Published: May 2007

The effect of fasting and refeeding on total antioxidant status (TAS), glutathione peroxidase (GSH-Px) activity and concentration of some non-enzymatic antioxidant compounds was studied in cockerels and pullets. Blood was collected before and after 48-h fasting and 24 h after refeeding. In cockerels, fasting resulted in a significant decrease of TAS and uric acid concentration. After refeeding, the concentration of TAS remained significantly lower as compared to the control level. At the same time, blood plasma level of total lipids increased in comparison to the control and post-fasting values. In pullets, fasting resulted in a significant decrease of whole blood haemolysate GSH-Px activity and blood plasma concentrations of albumin and uric acid. Simultaneously, a significant increase in total lipids and cholesterol was obtained. In pullets, refeeding resulted in a further decrease of TAS to undetectable values, a significant decrease of blood plasma cholesterol, and a significant increase of GSH-Px in the whole blood haemolysate and in blood plasma uric acid content. The results indicate that fasting has a negative impact on the antioxidant defence system of the blood, which leads to a reduced resistance to oxidative stress in both cockerels and pullets. However, pullets seem to be more susceptible to fasting-provoked oxidative stress than cockerels.
Mechanical devices to help in PennHIP examination
Authors: Ginja M. , Llorens-Pena Maria , Gonzalo-Orden J. , Ferreira A.
Published: May 2007

A modified PennHIP procedure (MPP), using specific mechanical holding devices, was used on 70 dogs and compared to the standard PennHIP method (SPM) used on 39 dogs, in terms of technical effectiveness and the mean number of essential individuals within the X-ray room (EIXRR). The data using the Chisquared test were consistent with the null hypothesis that the technical effectiveness was equal in the groups under investigation (P > 0.05). On the contrary, using the two-sample unpairedt-test the null hypothesis, that the mean EIXRR was equal, was rejected (P < 0.001). The estimated EIXRR was 3.4 ± 0.7 and 5.7 ± 1.2 (mean ± SD) for MPP and SPM, respectively. In conclusion, the MPP needs fewer EIXXR than the SPM and complies with the new recommendations in X-ray protection, which introduce the ALARA (as-low-as-reasonably-achievable) idea.
Prevalence of selected enteropathogenic bacteria in Hungarian finishing pigs
Authors: Biksi I. , Lőrincz Márta , Molnár Beáta , Kecskés T. , Takács N. , Mirt Darja , Cizek A. , Pejsak Z. , Martineau G. , Sevin J. , Szenci O.
Published: May 2007

The aim of this study was to obtain prevalence estimates about the most important enteropathogenic bacteria:Lawsonia intracellularis, Brachyspira hyodysenteriae, Brachyspira pilosicoli, Salmonella entericaandClostridium perfringensA and C in Hungarian farrow-to-finish pig herds. A total of 31 herds were selected, from where six pooled faecal samples, each containing three individual rectal faecal samples were collected from fattening pigs of 5–6 months of age. All 186 samples were examined by polymerase chain reaction (PCR) for the presence of the pathogens mentioned above.Lawsonia intracellulariswas found in 29 herds (93.55%) and in 108 samples (58.06%);B. hyodysenteriaein 14 herds (45.16%) and in 23 samples (12.37%);B. pilosicoliin 19 herds (61.29%) and in 53 samples (28.49%);S. entericain 17 herds (54.83%) and in 40 samples (21.50%). We detected the presence ofC. perfringensA in 19 herds (61.29%) and in 46 samples (24.73%), whileC. perfringensC was found in 8 herds (25.81%) and in 11 samples (5.91%). All examined herds were infected with one or more of these agents. Herds with diarrhoea in the mid-to late finishing phase had almost 10 times higher prevalence ofB. hyodysenteriaethan herds without such a history.
Relevance of serologic studies in inflammatory bowel diseases
Authors: Papp Mária , Altorjay István , Lakatos Péter
Published: May 2007

A gyulladásos bélbetegségekkel (IBD) kapcsolatos szerológiai markerek panelje rohamosan bővül. Leggyakrabban a
Saccharomyces cerevisiae
elleni antitesteket (ASCA) és az atípusos perinukleáris antineutrophil citoplazmatikus antitestet (atípusos P-ANCA) vizsgálták, de egyre több adat áll rendelkezésre az újabban felfedezett, különféle mikrobiális antigének ellen termelődő antitestekről is. Ilyenek például a külső membrán porin C-ellenes antitest (anti OmpC),
Pseudomonas fluorescens
ellenes antitest (anti-I2), valamint a glikánellenes antitestek (anti-laminaribioside carbohydrate antitest [ALCA]), anti-chitobioside carbohydrate antitest [ACCA]), anti-mannobioside carbohydrate antitest [AMCA]). Az anti-CBir1 (flagellin elleni antitest) az első olyan bakteriális antigén, mely állatmodellben colitist indukál, és IBD-betegekben is kóros immunválasz mutatható ki vele szemben. Az IBD jelenlegi diagnosztikus algoritmusában a különféle antitestek meghatározása mérsékelt szenzitivitásuk miatt kevés jelentőséggel bír. Újabban a szerológiai markereknek a betegség fenotípusával és lefolyásával való kapcsolata került az érdeklődés középpontjába. Egyre több adat támasztja alá, hogy Crohn-betegségben az egyes mikrobiális antigénekkel szemben termelődő antitestek számának, illetőleg azok titerének növekedése egyértelműen összefügg a szövődményes, agresszívebb betegséglefolyással. Felmerül annak a lehetősége is, hogy amennyiben a szerológiai válasz alapján sikerül homogén alcsoportok létrehozása, a terápia is tervezhetőbb lesz, illetőleg az IBD patomechanizmusának megértéséhez is közelebb kerülünk. További prospektív klinikai tanulmányok szükségesek azonban a szerológiai vizsgálatok valódi klinikai jelentőségének meghatározásához.
The state of the organised mammography screening in Hungary in 2006
Authors: Kovács Attila , Döbrőssy Lajos , Budai András , Boncz Imre , Cornides Ágnes
Published: May 2007

Magyarországon az emlőrák jelentős népegészségügyi probléma. A halálozás mérséklésére a tünetmentes asszonyok szervezett, azaz személyes behíváson, visszahíváson és utánkövetésen alapuló szűrővizsgálata a legígéretesebb módszer. A tapintásos emlővizsgálattal kiegészített mammográfiás szűrés az 50–65 éves korcsoportban bizonyítottan hatásos; praemenopausalis asszonyok esetében a hatásosság még nem bizonyított, ennek ellenére a közvélemény és a szakmai döntéshozókra nehezedő nyomás miatt a perimenopausalis korban levő (45 év feletti) asszonyokat nem rekesztik ki a szűrőprogramból. Magyarországon a Nemzeti Népegészségügyi Program megteremtette a szervezett emlőszűrés szervezeti, adminisztratív, jogszabályi és pénzügyi feltételeit, így a szűrőprogram 2002 óta működik. A két szűrési ciklus adatai szerint a szervezett szűrésen a meghívottak mintegy 40%-a vesz részt. Az Országos Egészségbiztosítási Pénztár észrevételei szerint a meghívásos szűrés hatására jelentősen megemelkedett a diagnosztikus mammográfiás vizsgálatok száma; ez arra utal, hogy számosan a szervezett szűrés keretein kívül keresik a szűrés lehetőségét. A szűrővizsgálattal felfedezett emlőrákok száma, ezen belül a kis rákok aránya a nemzetközi standard értékeknek megfelelő. Az ún. intervallumrákok gyakoriságának megállapítására a szűrési nyilvántartással együttműködő patológiai adatbank létesítése folyamatban van. A szervezett emlőszűrés egészség-gazdaságtani elemzés szerint elfogadható a finanszírozó számára.
Reevaluation of Eastern Oyster Dredge Efficiency in Survey Mode: Application in Stock Assessment
Authors: Powell Eric N. , Ashton-Alcox Kathryn A. , Kraeuter John N.
Published: May 2007

Dredge efficiency measurements were conducted in 2003 by comparing paired dredge and diver samples taken on eastern oyster Crassostrea virginica beds in the New Jersey waters of Delaware Bay. We evaluated whether ancillary data collected during the tow could be used to estimate dredge efficiency rather than periodically conducting costly field experiments. With the exception of market-size eastern oysters, dredge efficiency did not vary between the time when it was last measured (2000) and 2003. Dredge efficiencies were lower upbay in both studies. Capture efficiency was significantly greater for live eastern oysters than for boxes (dead, articulated valves) and significantly greater for boxes than for cultch (shell clumps, shells, and shell fragments without attached live eastern oysters or boxes) in both studies. In the single significant exception, dredge efficiency was significantly lower for market-size eastern oysters in 2003. Survey quantification of eastern oyster abundance by calibrating dredge performance requires recognition that dredge efficiencies are spatially variable and that this spatial variability is nonrandom. An analysis that focused on tow-based variables and variables describing fishing effort during the preceding 3 years revealed a suite of variables providing substantive information about the between-tow variation in dredge efficiency. These variables described aspects of catch volume, industry effort, and cultch availability. Each increased with increasing dredge efficiency. Selected subsets of these variables used in multiple-regression equations with data from an independent data set from the 2003 stock survey reproduced the estuarine gradient in dredge efficiency as well as the gradient in dredge efficiency from the highest values (for live eastern oysters) to the lowest values (for cultch). In only one case (market-size animals) did the efficiencies predicted from survey data using the multiple-regression equations diverge significantly from direct measurements. These analyses provide some confidence that estimates of dredge efficiency can be attained from tow-specific data.
Angler Exploitation of Redband Trout in Eight Idaho Desert Streams
Authors: Schill Daniel J. , LaBar George W. , Elle F. Steven , Mamer Elizabeth R. J. M.
Published: May 2007

We estimated angler exploitation rate for redband trout Oncorhynchus mykiss gairdneri in reaches of eight desert streams in southern Idaho using angler-reported catches of 716 jaw-tagged fish. Only two tagged redband trout were reported as harvested by anglers during the angling season. Estimates of annual angler exploitation for seven of the eight study reaches in question equate to 0.0% and from 3.4% to 5.7% on the Sinker Creek reach, depending on the assumed rate of angler tag reporting. Exploitation for the eight study reaches combined was 0.6–0.9%. Our results indicate that jaw tagging did not markedly reduce survival or catchability of redband trout. We conclude that redband trout residing in streams within southern Idaho are virtually unexploited and that angler harvest is well below levels observed on other Idaho redband trout fisheries in more accessible montane environments.
Observational Evidence of Spatial and Temporal Structure in a Sympatric Anadromous (Winter Steelhead) and Resident Rainbow Trout Mating System on the Olympic Peninsula, Washington
Authors: McMillan John R. , Katz Stephen L. , Pess George R.
Published: May 2007

We documented the spawning distribution and male mating tactics of sympatric anadromous rainbow trout Oncorhynchus mykiss (winter steelhead) and resident rainbow trout in the Calawah and Sol Duc River basins, Washington. Snorkel surveys and in situ behavioral observations were used to determine the spatial and temporal distribution patterns and male mating tactics of anadromous, resident, and hatchery residual fish across the spawning season. In general, male steelhead entered our survey reaches earlier than female steelhead, and both entered earlier than the wild resident and hatchery residual forms. Spatially, wild residents represented the greatest proportion of the population in the middle and upper survey reaches. Those differences coincided with mating attempts primarily between male and female steelhead early in the spawning season and primarily between female steelhead and wild resident males at the end of the season. Most of the mating attempts that we observed involved a single female and a single male steelhead, but attempts commonly included multiple male steelhead, wild resident males, or both, and behavioral tactics differed between forms. The patterns suggest a strong temporal structure and a lesser spatial structure to the distribution of O. mykiss during the spawning season, which has important implications for future studies of this complex species.
Generic Advertising and Product Differentiation Revisited
Authors: Crespi John M.
Published: May 2007

This paper revisits the analysis of generic commodity advertising under product differentiation by Crespi and Marette. Crespi and Marette had shown that a dominant firm producing high-quality goods and facing a competitive fringe of lower quality producers could be harmed by a generic advertising campaign while the fringe was left unaffected. Under this dominant-firm model, a question remained why these producers might support a program for which they were indifferent. In this paper we show that under a duopoly model a high-quality firm may be harmed while its lower-quality rival may be made better off by a generic program, thus helping to explain why some producers might favor a program while others do not. Further, this paper dismisses the claim made by some litigants that increased branded advertising is the result of a deleterious effect of generic advertising.
Experimental and CFD Characterization of Gas Dispersing Asymmetric Parabolic Blade Impellers
Authors: Kshatriya Sandeep S. , Patwardhan Ashwin W. , Eaglesham Archie
Published: May 2007

Enhanced operating performance can be obtained by combining the design characteristics of impellers. The asymmetricity of BT6 impeller blades when combined with symmetric ICI gasfoil blades results in two new diskless impeller designs, one with extension of the upper blade part (PBIUP) and the other with lower blade part (PBIDN). These impellers are experimentally characterized at intense agitation and sparging conditions for power draw, gas holdup and transition regimes. CFD modeling is used to evaluate the performance of impellers based on the pressure distribution and cavity formation on and around the impeller blades. Cavity formation on the new impellers is found to be higher as compared with ICI impeller but lower than BT6. The maximum experimental power drop at intense gas flow and agitation conditions for PBIUP and PBIDN is found to be 14% and 22% as compared to power drop of 10% for ICI gasfoil and 25% for BT6. The coalescence regions, identified from predicted gas holdup profiles, confirmed the experimental observations regarding the formation of larger bubbles in the tank. Overall, PBIUP is found to give uniform gas dispersion as compared to other impellers along with the desired objective of lower power drop.
Sequential Quantitative Trait Locus Mapping in Experimental Crosses
Authors: Satagopan Jaya M , Sen Saunak , Churchill Gary A.
Published: May 2007

The etiology of complex diseases is heterogeneous. The presence of risk alleles in one or more genetic loci affects the function of a variety of intermediate biological pathways, resulting in the overt expression of disease. Hence, there is an increasing focus on identifying the genetic basis of disease by systematically studying phenotypic traits pertaining to the underlying biological functions. In this paper we focus on identifying genetic loci linked to quantitative phenotypic traits in experimental crosses. Such genetic mapping methods often use a one stage design by genotyping all the markers of interest on the available subjects. A genome scan based on single locus or multi-locus models is used to identify the putative loci. Since the number of quantitative trait loci (QTLs) is very likely to be small relative to the number of markers genotyped, a one-stage selective genotyping approach is commonly used to reduce the genotyping burden, whereby markers are genotyped solely on individuals with extreme trait values. This approach is powerful in the presence of a single quantitative trait locus (QTL) but may result in substantial loss of information in the presence of multiple QTLs. Here we investigate the efficiency of sequential two stage designs to identify QTLs in experimental populations. Our investigations for backcross and F2 crosses suggest that genotyping all the markers on 60% of the subjects in Stage 1 and genotyping the chromosomes significant at 20% level using additional subjects in Stage 2 and testing using all the subjects provides an efficient approach to identify the QTLs and utilizes only 70% of the genotyping burden relative to a one stage design, regardless of the heritability and genotyping density. Complex traits are a consequence of multiple QTLs conferring main effects as well as epistatic interactions. We propose a two-stage analytic approach where a single-locus genome scan is conducted in Stage 1 to identify promising chromosomes, and interactions are examined using the loci on these chromosomes in Stage 2. We examine settings under which the two-stage analytic approach provides sufficient power to detect the putative QTLs.
Design and Testing of Classroom and Clinical Teaching Evaluation Tools for Nursing Education
Authors: Emerson Roberta J , Records Kathie
Published: May 2007

Student evaluations of teaching provide administrators an overall picture of the effectiveness of personnel and contribute data for promotion and merit decisions. These evaluations must be assessed for their relevance, validity, and reliability. This paper describes the development process and psychometric testing for clinical (n = 149) and didactic (n = 148) student evaluation of teaching forms for undergraduate and graduate courses in one college of nursing. Validity and reliability results were quite strong for the instruments, both of which evidenced a one-factor solution with factor loadings ranging from .68-.88 and Cronbach's alphas of .96 (Classroom) and .95 (Clinical). The clinical and classroom evaluation tools are relatively short, decreasing the burden on students who need to complete the instruments for multiple instructors in any one semester. Initial testing of the psychometric properties of the tools supports their continued use in colleges of nursing.
Pharmacology of Huperzine A, an Alkaloid Isolated from Huperzine Serrata, a Novel Cognition Enhancer with Dual Cholinergic and NMDA Action. Implications in Schizophrenia and Dementia
Authors: Chiu Simon S , Lalone Sarah , Goble Liz
Published: May 2007

Recently, there has been an escalating interest in exploring novel pharmacological approaches in Alzheimer Dementia and Schizophrenia. We reviewed the pharmacology of Huperzine A, an alkaloid isolated from Huperzia Serrata. The dual action of Huperzine in inhibiting cholinesterase activity and modulating the excitatory amino acid neurotransmitter NMDA (N-methyl-D-aspartic acid) makes the compound highly appealing as target in pharmaceutical development as a cognitive enhancer agent.
Essential Facility Access in Europe: Building a Test for Antitrust Policy
Authors: Castaldo Angelo , Nicita Antonio
Published: May 2007

This paper investigates the evolution of competition policy decisions in the US and, particularly, in the EU, concerning mandatory access to an essential facility held by a dominant firm. Based on some recent and controversial EU antitrust decisions, we outline a comprehensive test for identifying an essential facility and consequently imposing a mandatory access obligation on dominant firms.
Cost Effectiveness of R&D and Strategic Trade Policy
Authors: Kujal Praveen , Ruiz Juan M.
Published: May 2007

We analyze how the cost-effectiveness of R&D influences the incentives for governments to impose export subsidies. Governments first impose an export subsidy, or a tax. After observing export policy, firms invest in cost reducing R&D and subsequently compete in the market. Governments subsidize exports under Cournot competition. Under Bertrand competition and for linear demands and constant marginal costs, export subsidies are positive whenever R&D is sufficiently cost-effective at reducing marginal costs, and negative otherwise. The trade policy reversal found in models without endogenous sunk costs disappears if R&D is sufficiently cost-effective. Thus, output subsidies seem more robust than implied by the recent literature.
The Italian Regions' European Challenge: Comparing Four Strategies
Authors: Profeti Stefania
Published: May 2007

During the last two decades European cohesion policy exercised a considerable impact on sub-national institutions. In Italy, structural funds provided regions with new opportunities of participation in the European policy-making making them acquire a brand new role in the planning and management of local development policies. However, these opportunities required regions to be able to play an active role towards Brussels, to develop new administrative and organizational procedures and to put in place new mechanisms of territorial governance. This work, which examines the strategies carried out by four Italian regions to respond to such a threefold challenge, individuates the legacy of the past and the characteristics of political and administrative elites as the key factors which, if combined, are able to explain the timing and scope of regional responses.
The Digital Literacy of Seniors
Authors: Schäffer Burkhard
Published: May 2007

This article describes national and international comparative quantitative and qualitative empirical results for media use and media behaviour of elderly people against the background of demographic change and development in the sphere of information technology. Besides gender, professional position and educational qualification, age and affiliation to a generation are – in terms of ‘country’, origin or culture – the most significant predictors of whether someone is familiar with the computer and the Internet and whether he or she is using it in a competent way in private life and in their occupation. In addition to the international studies covered, this article focuses principally on the German situation, because the relative increase in the proportion of elderly people in that country has advanced the furthest in comparison with the rest of the world. Germany is playing a pioneering role in this respect. Searching for explanations which go beyond quantitative interpretation, a generation-specific model of cultures of media practice is being developed which favours the generation concept, in comparison with the ‘pure age’ concept, thus enabling a theory-based perspective with regard to demographic change. A generation-specific culture of media practice means approaching the current media technologies with those competences and restrictions which have been learned during adolescence and with the media available at that time.
The European Charter for Media Literacy: Meaning and Potential
Authors: Bachmair Ben , Bazalgette Cary
Published: May 2007

This article offers a brief outline of the background, origins and purposes of the European Charter for Media Literacy. The Charter constitutes a new approach to the formation of a network of media educators in Europe. Rather than proposing a bureaucratic organisation with formal membership, it offers a consensual definition of media literacy to which organisations and individuals can demonstrate their affiliation simply by signing the Charter online. The steady growth of registered visitors to the European Charter for Media Literacy website, and the number of Charter signatories nearing 200, indicates widespread interest and support for the concept; however, the effectiveness of the Charter as a catalyst for debate and collaboration remains to be proved.
The use of in vitro culture to improve the propagation of Rhododendron ponticum subsp. baeticum (Boiss. & Reuter)
Authors: Cantos Manuel , Linán Juana , García José , García-Linán María , Domínguez Miguel , Troncoso Antonio
Published: May 2007

Rhododendron ponticum subsp. baeticum is endemic in the southern region of the Iberian Peninsula. The relict populations of this species are vulnerable, due mainly to difficult conditions for the establishment of seedlings, resulting in a virtual lack of sexual recruitment. In order to preserve the surviving populations, in vitro culture methods have been applied for both the sexual and the agamic propagation of the species. The in vitro germination of seeds was high when conducted with Anderson’s medium without plant growth regulators. The self-rooted seedlings obtained were easily transplanted to outside conditions. The presence of growth regulators in the medium interfered with the development of the seedlings, causing heavy callus formation. The in vitro growth of explants took place readily in Anderson’s medium plus 0.072 mg L−1 of BA and 0.036 mg L−1 of NAA although the explants did not form roots. Rooting was achieved by the basal dipping of the explants in hydroalcoholic solutions of 500 mg L−1 IAA during the outside transplanting process. Therefore, the combination of in vitro grown explants together with ex vitro rooting, results in a good method for the agamic propagation of Rhododendron ponticum subsp. baeticum.
Pulp washing: Influence of temperature on lignin leaching from kraft pulps
Authors: Eriksson Gunnar , Grén Urban
Published: May 2007

The leaching of lignin from the fibre wall was studied in order to investigate the effects in the clean end of the fibre line. The focus was set on the short time intervals representative for the washing operation in industrial applications. The influence of temperature, pulp type and kappa number was investigated. It could be seen that there are different diffusivities for the soluble lignin in the wall at short and long time of leaching, probably due to the existence of a more open structure in an outer layer of the fibre wall, in which the lignin diffuses more easily and which is also emptied relatively fast, while diffusion of the lignin from the inner layers is significantly slower. There is also a relation between the leaching of sodium ions out of the wall and the short diffusion time of lignin, indicating a possible ion-ion interaction with the lignin in the outer layer of the fibre wall. The diffusivity of lignin increases more rapidly at temperatures above 80-90 "C. This temperature effect was confirmed in the results of wash test equipment experiments, giving noticeable differences above 100 "C. It was found that the experimentally determined lignin diffusivity differs for different kappa number and for type of pulp. The general behaviour of the phenomena, however, is the same.
Calendering of coated paper and board in an extended soft nip
Authors: Wikström M. , Nylund T. , Rigdahl M.
Published: May 2007

Several coated paper products were calendered at different line loads with an extended soft nip, a conventional soft (polymer/steel) nip and a hard (steel/steel) nip. The central roll of the calender was heated to different temperatures; 140, 180 and 210 oC with the extended soft nip, 140 oC with the conventional soft nip and 140 and 180 "C with the hard nip. Calendering with the extended soft nip resulted in general in a paper product with a more uniform structure than that obtained when the other two types of nips were used. This was reflected in lower gloss variations of the coated surface and in a lower variance in the reflectance of paper samples subjected to a bum-out treatment. The latter may be interpreted in terms of a more uniform pore structure in the coating layer. Offset prints on a coated woodfree paper chiendered with the extended soft nip were less mottled than prints on the same paper calendered with the conventional soft nip. There was apparently a correlation between the variance in the bum-out reflectance of the paper samples and the mottle in the offset print. The effect of the extended soft nip on gloss, print gloss, surface roughness and bending stiffness is also reported.
Die sozialintegrativen Wirkungen von Parks und Wäldern als gestaltete Naturräume. Erste Ergebnisse zweier Untersuchungen in der Schweiz und in Deutschland | Social Integrative Effects of Parks and Forests Designed as Natural Spaces. Initial Results of Two Investigations in Germany and Switzerland
Authors: Nicolè Simone , Seeland Klaus
Published: May 2007

Two studies in Germany and Switzerland looked at the question whether designed natural areas such as parks and forests could have positive effects on the social integration of disabled people. According to the degree of disability, differences were made out. Adequate access and infrastructure as well as a supportive information concept are essential for integration.
Workshop über Kriterien und Indikatoren für eine nachhaltige Bewirtschaftung des Schweizer Waldes | Workshop about Criteria and Indicators for Sustainable Forest Management in Switzerland
Authors: Schlaepfer Rodolphe , Bütler Rlta
Published: May 2007

A workshop about «Criteria and Indicators for Sustainable Forest Management in Switzerland» was organized by the Swiss Forest Agency, in order to enhance knowledge about the paneuropean criteria and indicators and their possible applications. The workshop results are to be used as recommendations for the discussions in progress about sustainable forest management targets and the need for future relevant scientific data. In particular, two criteria turned out to be insufficient for Swiss requirements: Maintenance, conservation and appropriate enhancement of biological diversity in forest ecosystems (Criterion 4), as well as Maintenance and appropriate enhancement of protective functions in forest management (Criterion 5). Further pertinent indicators were proposed. Additionally, there were many demands for giving more weight to «financial sustainability». The workshop concluded that there was a need to define targets for sustainable management of the Swiss forests and that better relations need to be created between international criteria and indicators and their application at the canton and management unit level.