bluuebunny/crossref_metadata_2025 huggingface dataset:
Occupational exposure to isoflurane during anaesthesia induction with standard and scavenging double masks in dogs, pigs and ponies
Authors: Säre H , Ambrisko T D , Moens Y
Published: May 2011

Induction of anaesthesia using a face mask may cause workplace pollution with anaesthetics. The aim of this study was to compare the effect of the use of a standard versus a scavenging double face mask on isoflurane pollution during induction of anaesthesia in experimental animals: six dogs, 12 pigs and five ponies. Pigs were anaesthetized only once using either mask type randomly ( n = 6). Dogs and ponies were anaesthetized twice, using different mask types for each occasion in a random order with at least 14 days between experiments. The masks were attached to a Bain breathing system (dogs and pigs) or to a circle system (ponies) using a fresh gas flow of 300 or 50 mL/kg/min, respectively, with 5% vaporizer dial setting. Isoflurane concentrations were measured in the anaesthetist's breathing zone using an infrared photoacoustic spectrometer. The peak isoflurane concentrations (pollution) during baseline and induction periods were compared with Wilcoxon test in all species, and values between the mask types were compared with either Wilcoxon (ponies and dogs) or Mann–Whitney tests (pigs) ( P < 0.05). Pollution was higher during induction when compared with baseline regardless of the mask type used but it was only statistically significant in dogs and pigs. Pollution was lower during induction with double versus single masks but it was only significant in pigs. Despite the lack of statistical significance, large and consistent differences were noted in all species, hence using scavenging masks is recommended to reduce isoflurane workplace pollution.
Data-Mining-Driven Neighborhood Search
Authors: Samorani Michele , Laguna Manuel
Published: May 2011

Metaheuristic approaches based on the neighborhood search escape local optimality by applying predefined rules and constraints, such as tabu restrictions (in tabu search), acceptance criteria (in simulated annealing), and shaking (in variable neighborhood search). We propose a general approach that attempts to learn (off-line) the guiding constraints that, when applied online, will result in effective escape directions from local optima. Given a class of problems, the learning process is performed off-line, and the results are applied to constrained neighborhood searches to guide the solution process out of local optimality. Computational results on the constrained task allocation problem show that adding these guiding constraints to a simple tabu search improves the quality of the solutions found, making the overall method competitive with state-of-the-art methods for this class of problems. We also present a second set of tests on the matrix bandwidth minimization problem.
A Hybrid Tabu Search and Constraint Programming Algorithm for the Dynamic Dial-a-Ride Problem
Authors: Berbeglia Gerardo , Cordeau Jean-François , Laporte Gilbert
Published: May 2011

This paper introduces a hybrid algorithm for the dynamic dial-a-ride problem in which service requests arrive in real time. The hybrid algorithm combines an exact constraint programming algorithm and a tabu search heuristic. An important component of the tabu search heuristic consists of three scheduling procedures that are executed sequentially. Experiments show that the constraint programming algorithm is sometimes able to accept or reject incoming requests, and that the hybrid method outperforms each of the two algorithms when they are executed alone.
The Balanced Minimum Evolution Problem
Authors: Catanzaro Daniele , Labbé Martine , Pesenti Raffaele , Salazar-González Juan-José
Published: May 2011

Aphylogeny is an unrooted binary tree that represents the evolutionary relationships of a set of n species. Phylogenies find applications in several scientific areas ranging from medical research, to drug discovery, to epidemiology, to systematics, and to population dynamics. In such applications, the available information is usually restricted to the leaves of a phylogeny and is represented by molecular data extracted from the analyzed species, such as DNA, RNA, amino acid, or codon fragments. On the contrary, the information about the phylogeny itself is generally missing and is determined by solving an optimization problem, called the phylogeny estimation problem (PEP), whose versions depend on the criterion used to select a phylogeny from among plausible alternatives. In this paper, we investigate a recent version of the PEP, called the balanced minimum evolution problem (BMEP). We present a mixed-integer linear programming model to exactly solve instances of the BMEP and develop branching rules and families of valid inequalities to further strengthen the model. Our results give perspective on the mathematics of the BMEP and suggest new directions on the development of future efficient exact approaches to solutions of the problem.
Modeling Cross Correlation in Three-Moment Four-Parameter Decomposition Approximation of Queueing Networks
Authors: Kim Sunkyo
Published: May 2011

In two-moment decomposition approximations of queueing networks, the arrival process is modeled as a renewal process, and each station is approximated as a GI/G/1 queue whose mean waiting time is approximated based on the first two moments of the interarrival times and the service times. The departure process is also approximated as a renewal process even though the autocorrelation of this process may significantly affect the performance of the subsequent queue depending on the traffic intensity. When the departure process is split into substreams by Markovian random routing, the split processes typically are modeled as independent renewal processes even though they are correlated with each other. This cross correlation might also have a serious impact on the queueing performance. In this paper, we propose an approach for modeling both the cross correlation and the autocorrelation by a three-moment four-parameter decomposition approximation of queueing networks. The arrival process is modeled as a nonrenewal process by a two-state Markov-modulated Poisson process, viz., MMPP(2). The cross correlation between randomly split streams is accounted for in the second and third moments of the merged process by the innovations method. The main contribution of the present research is that both the cross correlation and the autocorrelation can be modeled in parametric decomposition approximations of queueing networks by integrating the MMPP(2) approximation of the arrival/departure process and the innovations method. We also present numerical results that strongly support our refinements.
TECHNICAL NOTE—Revenue Management with Bargaining
Authors: Bhandari Atul , Secomandi Nicola
Published: May 2011

Static game-theoretic models of bilateral bargaining assume that the seller knows his valuation for the item that is up for sale; that is, how the seller may determine this quantity is exogenous to these models. In this paper, we develop and analyze a stylized Markov decision process that endogenizes the seller's computation of his marginal inventory valuation in an infinite-horizon revenue management setting when each sale occurs according to a given bilateral bargaining mechanism. We use this model to compare, both analytically and numerically, the seller's performance under four basic bilateral bargaining mechanisms with a tractable information structure. These comparisons provide insights into the seller's performance under the following trading arrangements: buyer and seller posted pricing, negotiated pricing, and rule-based pricing.
Reorganizing the Boundaries of Trust: From Discrete Alternatives to Hybrid Forms
Authors: McEvily Bill
Published: May 2011

In this essay I propose that trust be reconceptualized as a family of hybrid form concepts. I argue that trust and risk frequently co-occur and overlap. In conjunction, the concepts produce hybrid social judgments that combine elements of trust and risk. The point of overlap among trust and risk centers on the choice to be vulnerable to the decisions and actions of another party. However, the types of decision making and information processing involved represent important differences between the two types of social judgments. Whereas risk involves probabilistic decision making and more controlled information processing, trust involves heuristic decision making and more automatic information processing. I conclude with a discussion of new directions for organizational research based on the notion of hybrid forms of trust.
Regions Matter: How Localized Social Capital Affects Innovation and External Knowledge Acquisition
Authors: Laursen Keld , Masciarelli Francesca , Prencipe Andrea
Published: May 2011

To introduce new products, firms often use knowledge from other organizations. Drawing on social capital theory and the relational view of the firm, we argue that geographically localized social capital affects a firm's ability to innovate through various external channels. Combining data on social capital at the regional level, with a large-scale data set of the innovative activities of a representative sample of 2,413 Italian manufacturing firms from 21 regions, and controlling for a large set of firm and regional characteristics, we find that being located in a region characterized by a high level of social capital leads to a higher propensity to innovate. We find also that being located in an area characterized by a high degree of localized social capital is complementary to firms' investments in internal research and development (R&D) and that such a location positively moderates the effectiveness of externally acquired R&D on the propensity to innovate.
Cognitive Development and Down Syndrome: Age-Related Change on the Stanford-Binet Test (Fourth Edition)
Authors: Couzens Donna , Cuskelly Monica , Haynes Michele
Published: May 2011

Growth models for subtests of the Stanford-Binet Intelligence Scale, 4th edition (R. L. Thorndike, E. P. Hagen, & J. M. Sattler, 1986a, 1986b) were developed for individuals with Down syndrome. Models were based on the assessments of 208 individuals who participated in longitudinal and cross-sectional research between 1987 and 2004. Variation in performance among individuals was large and significant across all subtests except Memory for Sentences. Scores on the Memory for Sentences subtest remained low between ages 4 to 30 years. Greatest variation was found on the Pattern Analysis subtest, where scores continued to rise into adulthood. Turning points for scores on the Vocabulary and Comprehension subtests appeared premature relative to normative patterns of development. The authors discuss development at the subdomain level and analyze both individual and group trajectories.
Physical Activity Benefits and Needs in Adults With Intellectual Disabilities: Systematic Review of the Literature
Authors: Bartlo Pamela , Klein Penelope J.
Published: May 2011

Regular physical activity is vital for adult individuals with intellectual disabilities. The purpose of this review was to assess critically the evidence on effectiveness of physical activity interventions for adults with intellectual disability. An electronic database search was conducted. Research was then assessed for methodological rigor, and strength of the evidence was determined. Eleven clinical studies met inclusion criteria. Interventions studied included a variety of physical activity modes. Critical review revealed moderate to strong evidence that physical activity positively affected balance, muscle strength, and quality of life in individuals with intellectual disability. The authors also found that the research in this area needs to be translated into practice, specifically the development of physical activity programs that are adaptable to the needs of individuals with intellectual disability.
Paradoxical Enhancement of Fear Extinction Memory and Synaptic Plasticity by Inhibition of the Histone Acetyltransferase p300
Authors: Marek Roger , Coelho Carlos M. , Sullivan Robert K. P. , Baker-Andresen Danay , Li Xiang , Ratnu Vikram , Dudley Kevin J. , Meyers David , Mukherjee Chandrani , Cole Philip A. , Sah Pankaj , Bredy Timothy W.
Published: May 2011

It is well established that the coordinated regulation of activity-dependent gene expression by the histone acetyltransferase (HAT) family of transcriptional coactivators is crucial for the formation of contextual fear and spatial memory, and for hippocampal synaptic plasticity. However, no studies have examined the role of this epigenetic mechanism within the infralimbic prefrontal cortex (ILPFC), an area of the brain that is essential for the formation and consolidation of fear extinction memory. Here we report that a postextinction training infusion of a combined p300/CBP inhibitor (Lys-CoA-Tat), directly into the ILPFC, enhances fear extinction memory in mice. Our results also demonstrate that the HAT p300 is highly expressed within pyramidal neurons of the ILPFC and that the small-molecule p300-specific inhibitor (C646) infused into the ILPFC immediately after weak extinction training enhances the consolidation of fear extinction memory. C646 infused 6 h after extinction had no effect on fear extinction memory, nor did an immediate postextinction training infusion into the prelimbic prefrontal cortex. Consistent with the behavioral findings, inhibition of p300 activity within the ILPFC facilitated long-term potentiation (LTP) under stimulation conditions that do not evoke long-lasting LTP. These data suggest that one function of p300 activity within the ILPFC is to constrain synaptic plasticity, and that a reduction in the function of this HAT is required for the formation of fear extinction memory.
An Anatomical Basis for Opponent Process Mechanisms of Opiate Withdrawal
Authors: Radke Anna K. , Rothwell Patrick E. , Gewirtz Jonathan C.
Published: May 2011

Opponent process theory predicts that the first step in the induction of drug withdrawal is the activation of reward-related circuitry. Using the acoustic startle reflex as a model of anxiety-like behavior in rats, we show the emergence of a negative affective state during withdrawal after direct infusion of morphine into the ventral tegmental area (VTA), the origin of the mesolimbic dopamine system. Potentiation of startle during withdrawal from systemic morphine exposure requires a decrease in opiate receptor stimulation in the VTA and can be relieved by administration of the dopamine receptor agonist apomorphine. Together, our results suggest that the emergence of anxiety during withdrawal from acute opiate exposure begins with activation of VTA mesolimbic dopamine circuitry, providing a mechanism for the opponent process view of withdrawal.
Dorsal Striatal D2-Like Receptor Availability Covaries with Sensitivity to Positive Reinforcement during Discrimination Learning
Authors: Groman Stephanie M. , Lee Buyean , London Edythe D. , Mandelkern Mark A. , James Alex S. , Feiler Karen , Rivera Ronald , Dahlbom Magnus , Sossi Vesna , Vandervoort Eric , Jentsch J. David
Published: May 2011

Deviations in reward sensitivity and behavioral flexibility, particularly in the ability to change or stop behaviors in response to changing environmental contingencies, are important phenotypic dimensions of several neuropsychiatric disorders. Neuroimaging evidence suggests that variation in dopamine signaling through dopamine D2-like receptors may influence these phenotypes, as well as associated psychiatric conditions, but the specific neurocognitive mechanisms through which this influence is exerted are unknown. To address this question, we examined the relationship between behavioral sensitivity to reinforcement during discrimination learning and D2-like receptor availability in vervet monkeys. Monkeys were assessed for their ability to acquire, retain, and reverse three-choice, visual-discrimination problems, and once behavioral performance had stabilized, they received positron emission tomography (PET) scans. D2-like receptor availability in dorsal aspects of the striatum was not related to individual differences in the ability to acquire or retain visual discriminations but did relate to the number of trials required to reach criterion in the reversal phase of the task. D2-like receptor availability was also strongly correlated with behavioral sensitivity to positive, but not negative, feedback during learning. These results go beyond electrophysiological findings by demonstrating the involvement of a striatal dopaminergic marker in individual differences in feedback sensitivity and behavioral flexibility, providing insight into the neural mechanisms that are affected in neuropsychiatric disorders that feature these deficits.
Real-World Scene Representations in High-Level Visual Cortex: It's the Spaces More Than the Places
Authors: Kravitz Dwight J. , Peng Cynthia S. , Baker Chris I.
Published: May 2011

Real-world scenes are incredibly complex and heterogeneous, yet we are able to identify and categorize them effortlessly. In humans, the ventral temporal parahippocampal place area (PPA) has been implicated in scene processing, but scene information is contained in many visual areas, leaving their specific contributions unclear. Although early theories of PPA emphasized its role in spatial processing, more recent reports of its function have emphasized semantic or contextual processing. Here, using functional imaging, we reconstructed the organization of scene representations across human ventral visual cortex by analyzing the distributed response to 96 diverse real-world scenes. We found that, although individual scenes could be decoded in both PPA and early visual cortex (EVC), the structure of representations in these regions was vastly different. In both regions, spatial rather than semantic factors defined the structure of representations. However, in PPA, representations were defined primarily by the spatial factor of expanse (open, closed) and in EVC primarily by distance (near, far). Furthermore, independent behavioral ratings of expanse and distance correlated strongly with representations in PPA and peripheral EVC, respectively. In neither region was content (manmade, natural) a major contributor to the overall organization. Furthermore, the response of PPA could not be used to decode the high-level semantic category of scenes even when spatial factors were held constant, nor could category be decoded across different distances. These findings demonstrate, contrary to recent reports, that the response PPA primarily reflects spatial, not categorical or contextual, aspects of real-world scenes.
Developmental Sculpting of Dendritic Morphology of Layer 4 Neurons in Visual Cortex: Influence of Retinal Input
Authors: Callaway Edward M. , Borrell Víctor
Published: May 2011

Dendritic morphology determines the kinds of input a neuron receives, having a profound impact on neural information processing. In the mammalian cerebral cortex, excitatory neurons have been ascribed to one of two main dendritic morphologies, either pyramidal or stellate, which differ mainly on the extent of the apical dendrite. Developmental mechanisms regulating the emergence and refinement of dendritic morphologies have been studied for cortical pyramidal neurons, but little is known for spiny stellate neurons. Using biolistics to label single cells on acute brain slices of the ferret primary visual cortex, we show that neurons in layer 4 develop in a two-step process: initially, all neurons appear pyramidal, growing a prominent apical dendrite and few small basal dendrites. Later, a majority of these neurons show a change in the relative extent of basal and apical dendrites that results in a gradual sculpting into a stellate morphology. We also find that ∼22% of neurons maintain the proportionality of their dendritic arbors, remaining as pyramidal cells at maturity. When ferrets were deprived of retinal input at early stages of postnatal development by binocular enucleation, a significant proportion of layer 4 spiny neurons failed to remodel their apical dendrites, and ∼55% remained as pyramidal neurons. Our results demonstrate that cortical spiny stellate neurons emerge by differential sculpting of the dendritic arborizations of an initial pyramidal morphology and that sensory input plays a fundamental role in this process.
ZPK/DLK, a Mitogen-Activated Protein Kinase Kinase Kinase, Is a Critical Mediator of Programmed Cell Death of Motoneurons
Authors: Itoh Aki , Horiuchi Makoto , Wakayama Kouji , Xu Jie , Bannerman Peter , Pleasure David , Itoh Takayuki
Published: May 2011

Activation of mitogen-activated protein kinase pathways is critically involved in naturally occurring programmed cell death of motoneurons during development, but the upstream mediators remain undetermined. We found that mice deficient in ZPK, also called DLK (ZPK/DLK), an upstream kinase in these pathways, have twice as many spinal motoneurons as do their wild-type littermates. Nuclear HB9/MNX1-positive motoneuron pools were generated similarly in the spinal cord of both ZPK/DLK-deficient and wild-type embryos. Thereafter, however, significantly less apoptotic motoneurons were found in ZPK/DLK-deficient embryos compared with wild-type embryos, resulting in retention of excess numbers of motoneurons after birth. Notably, these excess motoneurons remained viable without atrophic changes in the ZPK/DLK-deficient mice surviving into adulthood. Analysis of the diaphragm and the phrenic nerve revealed that clustering and innervation of neuromuscular junctions were indistinguishable between ZPK/DLK-deficient and wild-type mice, whereas the proximal portion of the phrenic nerve of ZPK/DLK-deficient mice contained significantly more axons than the distal portion. This result supports the hypothesis that some excess ZPK/DLK-deficient motoneurons survived without atrophy despite failure to establish axonal contact with their targets. This study provides compelling evidence for a critical role for ZPK/DLK in naturally occurring programmed cell death of motoneurons and suggests that ZPK/DLK could become a strategic therapeutic target in motor neuron diseases in which aberrant activation of the apoptogenic cascade is involved.
Eye Position Effects in Oculomotor Plasticity and Visual Localization
Authors: Zimmermann Eckart , Lappe Markus
Published: May 2011

For visual localization to remain accurate across changes of gaze, a signal representing the position of the eye in the orbita is needed to code spatial locations in a reference frame that is independent of retinal displacements. Here we report evidence that the localization of visual objects in space is coded in an extraretinal reference frame. In human subjects, we used outward saccadic adaptation, which can be induced artificially by a systematic displacement of the saccade target. This form of oculomotor plasticity is accompanied by changes in spatial perception, thus highlighting the relevance of saccade metrics for visual localization. We tested the reference frame of outward adaptation for reactive and scanning saccades and visual localization. For scanning saccades, adaptation magnitude was drastically reduced at positions distant from the adapted eye position. Changes in visual localization showed a very similar modulation of eye position. These results suggest that scanning saccade adaptation is encoded in a nonretinotopic reference frame. Eye position effects for reactive saccade adaptation were smaller, and the induced mislocalization did not vary significantly between eye positions. The different modulation of reactive and scanning saccade adaptation supports the idea that oculomotor plasticity can occur at multiple sites in the brain. The findings are also consistent with previous evidence for a stronger influence of scanning saccade adaptation on the visual localization of objects in space.
The Robustness ofCaenorhabditis elegansMale Mating Behavior Depends on the Distributed Properties of Ray Sensory Neurons and Their Output through Core and Male-Specific Targets
Authors: Koo Pamela K. , Bian Xuelin , Sherlekar Amrita L. , Bunkers Meredith R. , Lints Robyn
Published: May 2011

Many evolutionarily significant behaviors, such as mating, involve dynamic interactions with animate targets. This raises the question of what features of neural circuit design are essential to support these complex types of behavior. TheCaenorhabditis elegansmale uses 18 ray sensilla of the tail to coordinate mate apposition behavior, which facilitates a systematic search of the hermaphrodite surface for the vulva. Precisely how ray neuron types, A and B, robustly endow the male with a high degree of spatial and temporal precision is unknown. We show that the appositional postures that drive the search trajectory reflect the complex interplay of ray neuron type-induced motor outputs. Cell-type-specific ablations reveal that the A-neurons are required for all appositional postures. Their activity is instructive because the A-neurons can induce scanning- and turning-like appositional postures when artificially activated with channelrhodopsin (ChR2). B-neurons are essential only for initiation of the behavior in which they enhance male responsiveness to hermaphrodite contact. When artificially activated using ChR2, A- and B-neurons produce different tail ventral curl postures. However, when coactivated, A-neuron posture dominates, limiting B-neuron contributions to initiation or subsequent postures. Significantly, males lacking the majority of rays retain a high degree of postural control, indicating significant functional resilience in the system. Furthermore, eliminating a large number of male-specific ray neuron targets only partially attenuates tail posture control revealing that gender-common cells make an important contribution to the behavior. Thus, robustness may be a crucial feature of circuits underlying complex behaviors, such as mating, even in simple animals.
Contrasting Roles for Dopamine D1 and D2 Receptor Subtypes in the Dorsomedial Striatum but Not the Nucleus Accumbens Core during Behavioral Inhibition in the Stop-Signal Task in Rats
Authors: Eagle Dawn M. , Wong Jacky C. K. , Allan Michelle E. , Mar Adam C. , Theobald David E. , Robbins Trevor W.
Published: May 2011

Dopamine and dopamine-receptor function are often implicated in behavioral inhibition, and deficiencies within behavioral inhibition processes linked to attention deficit/hyperactivity disorder (ADHD), schizophrenia, obsessive-compulsive disorder, and drug addiction. In the stop-signal task, which measures the speed of the process of inhibition [stop-signal reaction time (SSRT)], psychostimulant-related improvement of SSRT in ADHD is linked with dopamine function. However, the precise nature of dopaminergic control over SSRT remains unclear.

This study examined region- and receptor-specific modulation of SSRT in the rat using direct infusions of the dopamine D1 receptor (DRD1) antagonist SCH 23390 or dopamine D2 receptor (DRD2) antagonist sulpiride into the dorsomedial striatum (DMStr) or nucleus accumbens core (NAcbC). DRD1 and DRD2 antagonists had contrasting effects on SSRT that were specific to the DMStr. SCH 23390 decreased SSRT with little effect on the go response. Conversely, sulpiride increased SSRT but also increased go-trial reaction time and reduced trial completion at the highest doses. These results suggest that DRD1 and DRD2 function within the DMStr, but not the NAcbC, may act to balance behavioral inhibition in a manner that is independent of behavioral activation.
Functional Alterations to the Nigrostriatal System in Mice Lacking All Three Members of the Synuclein Family
Authors: Anwar Sabina , Peters Owen , Millership Steven , Ninkina Natalia , Doig Natalie , Connor-Robson Natalie , Threlfell Sarah , Kooner Gurdeep , Deacon Robert M. , Bannerman David M. , Bolam J. Paul , Chandra Sreeganga S. , Cragg Stephanie J. , Wade-Martins Richard , Buchman Vladimir L.
Published: May 2011

The synucleins (α, β, and γ) are highly homologous proteins thought to play a role in regulating neurotransmission and are found abundantly in presynaptic terminals. To overcome functional overlap between synuclein proteins and to understand their role in presynaptic signaling from mesostriatal dopaminergic neurons, we produced mice lacking all three members of the synuclein family. The effect on the mesostriatal system was assessed in adult (4- to 14-month-old) animals using a combination of behavioral, biochemical, histological, and electrochemical techniques. Adult triple-synuclein-null (TKO) mice displayed no overt phenotype and no change in the number of midbrain dopaminergic neurons. TKO mice were hyperactive in novel environments and exhibited elevated evoked release of dopamine in the striatum detected with fast-scan cyclic voltammetry. Elevated dopamine release was specific to the dorsal not ventral striatum and was accompanied by a decrease of dopamine tissue content. We confirmed a normal synaptic ultrastructure and a normal abundance of SNARE (solubleN-ethylmaleimide-sensitive factor attachment protein receptor) protein complexes in the dorsal striatum. Treatment of TKO animals with drugs affecting dopamine metabolism revealed normal rate of synthesis, enhanced turnover, and reduced presynaptic striatal dopamine stores. Our data uniquely reveal the importance of the synuclein proteins in regulating neurotransmitter release from specific populations of midbrain dopamine neurons through mechanisms that differ from those reported in other neurons. The finding that the complete loss of synucleins leads to changes in dopamine handling by presynaptic terminals specifically in those regions preferentially vulnerable in Parkinson's disease may ultimately inform on the selectivity of the disease process.
Na+–Ca2+Exchanger (NCX3) Knock-Out Mice Display an Impairment in Hippocampal Long-Term Potentiation and Spatial Learning and Memory
Authors: Molinaro Pasquale , Viggiano Davide , Nisticò Robert , Sirabella Rossana , Secondo Agnese , Boscia Francesca , Pannaccione Anna , Scorziello Antonella , Mehdawy Bisan , Sokolow Sophie , Herchuelz André , Di Renzo Gianfranco F. , Annunziato Lucio
Published: May 2011

Long-term potentiation (LTP) depends on the coordinated regulation of an ensemble of proteins related to Ca2+homeostasis, including Ca2+transporters. One of the major players in the regulation of intracellular Ca2+([Ca2+]i) homeostasis in neurons is the sodium/calcium exchanger (NCX), which represents the principal mechanism of Ca2+clearance in the synaptic sites of hippocampal neurons. Because NCX3, one of the three brain isoforms of the NCX family, is highly expressed in the hippocampal subfields involved in LTP, we hypothesized that it might represent a potential candidate for LTP modulation. To test this hypothesis, we first examined the effect ofncx3gene ablation on NCX currents (INCX) and Ca2+homeostasis in hippocampal neurons.ncx3−/−neurons displayed a reducedINCX, a higher basal level of [Ca2+]i, and a significantly delayed clearance of [Ca2+]ifollowing depolarization. Furthermore, measurement of field EPSPs, recorded from the CA1 area, revealed thatncx3−/−mice had an impaired basal synaptic transmission. Moreover, hippocampal slices fromncx3−/−mice exhibited a worsening in LTP compared with congenicncx3+/+. Consistently, immunohistochemical and immunoblot analysis indicated that in the hippocampus ofncx3−/−mice both Ca2+/calmodulin-dependent protein kinase IIα (CaMKIIα) expression and the phosphoCaMKIIα/CaMKIIα ratio were significantly reduced compared withncx3+/+. Interestingly,ncx3−/−mice displayed a reduced spatial learning and memory performance, as revealed by the novel object recognition, Barnes maze, and context-dependent fear conditioning assays. Collectively, our findings demonstrate that the deletion of thencx3gene in mice has detrimental consequences on basal synaptic transmission, LTP regulation, spatial learning, and memory performance.
Ventromedial Frontal Lobe Damage Disrupts Value Maximization in Humans
Authors: Camille Nathalie , Griffiths Cathryn A. , Vo Khoi , Fellows Lesley K. , Kable Joseph W.
Published: May 2011

Recent work in neuroeconomics has shown that regions in orbitofrontal and medial prefrontal cortex encode the subjective value of different options during choice. However, these electrophysiological and neuroimaging studies cannot demonstrate whether such signals are necessary for value-maximizing choices. Here we used a paradigm developed in experimental economics to empirically measure and quantify violations of utility theory in humans with damage to the ventromedial frontal lobe (VMF). We show that people with such damage are more likely to make choices that violate the generalized axiom of revealed preference, which is the one necessary and sufficient condition for choices to be consistent with value maximization. These results demonstrate that the VMF plays a critical role in value-maximizing choice.
Calcium/Calmodulin-Dependent Protein Kinase II Mediates Group I Metabotropic Glutamate Receptor-Dependent Protein Synthesis and Long-Term Depression in Rat Hippocampus
Authors: Mockett Bruce G. , Guévremont Diane , Wutte Magdalena , Hulme Sarah R. , Williams Joanna M. , Abraham Wickliffe C.
Published: May 2011

Activation of Group I metabotropic glutamate receptors (mGluRs) in rat hippocampus induces a form of long-term depression (LTD) that is dependent on protein synthesis. However, the intracellular mechanisms leading to the initiation of protein synthesis and expression of LTD after mGluR activation are only partially understood. We investigated the role of several pathways linked to mGluR activation, translation initiation, and induction of LTD. We found that Group I mGluR-dependent protein synthesis and associated LTD, as induced by the agonist (RS)-3,5-dihydrophenylglycine (DHPG) or paired-pulse synaptic stimulation, was dependent on activation of calcium/calmodulin-dependent protein kinase IIα (CaMKII). DHPG induced a transient increase in the level of phospho-CaMKII (phospho-CaMKIIT286) in synaptoneurosomes prepared from whole hippocampus and in CA1 minislices. In synaptoneurosomes, DHPG also induced an increase in phosphorylation of eIF4E, and an increase in protein synthesis that was abolished by translation inhibitors and the CaMKII inhibitors 1-[N,O-bis(5-isoquinolinesulphonyl)-N-methyl-l-tyrosyl]-4-phenylpiperazine (KN62) and 2-[N-(2-hydroxyethyl)]-N-(4-methoxybenzenesulfonyl)amino-N-(4-chloro-cinnamyl)-N-methylbenzylamine (KN93). In field recordings from CA1, both the translation inhibitor cycloheximide and KN62 significantly reduced DHPG-induced LTD. Combined application did not further reduce the LTD, suggesting a common mechanism. In whole-cell recordings, a third CaMKII inhibitor, AIP (autocamtide-2-related inhibitory peptide), significantly reduced the DHPG-induced LTD of synaptic currents. Inhibition of the classical pathway mediating many Group I mGluR effects by blocking PKC (protein kinase C) or PLC (phospholipase C) did not impair DHPG-induced protein synthesis or LTD. Collectively, these findings demonstrate an important role for CaMKII in mediating the initiation of protein synthesis that then supports the postsynaptic expression of DHPG-induced LTD.
Probing TARP Modulation of AMPA Receptor Conductance with Polyamine Toxins
Authors: Jackson Alexander C. , Milstein Aaron D. , Soto David , Farrant Mark , Cull-Candy Stuart G. , Nicoll Roger A.
Published: May 2011

The properties of synaptic AMPA receptors (AMPARs) depend on their subunit composition and association with transmembrane AMPAR regulatory proteins (TARPs). Although both GluA2 incorporation and TARP association have been shown to influence AMPAR channel conductance, the manner in which different TARPs modulate the mean channel conductance of GluA2-containing AMPARs is unknown. Using ultrafast agonist application and nonstationary fluctuation analysis, we found that TARP subtypes differentially increase the mean channel conductance, but not the peak open probability, of recombinant GluA2-containing AMPARs. TARP γ-8, in particular, enhances mean channel conductance to a greater degree than γ-2, γ-3, or γ-4. We then examined the action of a use-dependent antagonist of GluA2-containing AMPARs, philanthotoxin-74 (PhTx-74), on recombinant AMPARs and on GluA2-containing AMPARs in cerebellar granule neurons fromstargazermice transfected with TARPs. We found that the rate and extent of channel block varies with TARP subtype, in a manner that correlates linearly with mean channel conductance. Furthermore, block of GluA2-containing AMPARs by polyamine toxins varied depending on whether channels were activated by the full agonist glutamate or the partial agonist kainate, consistent with conductance state-dependent block. Block of GluA2-lacking AMPARs by PhTx-433 is also modulated by TARP association and is a function of agonist efficacy. Our data indicate that channel block by polyamine toxins is sensitive to the mean channel conductance of AMPARs, which varies with TARP subtype and agonist efficacy. Furthermore, our results illustrate the utility of polyamine toxins as sensitive probes of AMPAR channel conductance and suggest the possibility that TARPs may influence their channel properties by selectively stabilizing specific channel conformations, rather than altering the pore structure.
“Focus pronouns” in Old Latin reflexive constructions
Authors: Lühr Rosemarie
Published: May 2011

This paper deals with a Latin reflexivization strategy distinct from other reflexive constructions. It consists of first and second person pronouns which are used to emphasize the first and second person referents in Old Latin comedy by certain emphasizing elements like ‑met in egomet or ‑te in tūte. The form and function of these emphasizing personal pronouns has not been observed and described yet. Moreover, the grammatical, semantic and pragmatic status of this reflexivization strategy has hitherto been unknown. The elements ‑met and ‑te are likely to be derived from suffixes which have an identifying and emphasizing function similar to German selbst ‘self’. Reflexivization here obviously is connected to focalization, a typologically well-known relationship.
An Effective Quarantine Measure Reduced the Total Incidence of Influenza A H1N1 in the Workplace: Another Way to Control the H1N1 Flu Pandemic
Authors: Miyaki Koichi , Sakurazawa Hirofumi , Mikurube Hajime , Nishizaka Mika , Ando Hidehiko , Song Yixuan , Shimbo Takuro
Published: May 2011

An Effective Quarantine Measure Reduced the Total Incidence of Influenza A H1N1 in the Workplace: Another Way to Control the H1N1 Flu Pandemic: Koichi Miyaki, et al. Department of Clinical Research and Informatics, National Center for Global Health and Medicine—

Objectives

To evaluate the effectiveness of a non‐vaccine quarantine measure against pandemic influenza A H1N1 in workplaces.

Methods

Design was quasi‐cluster randomized controlled trial in two sibling companies (Cohort 1 n=6,634, Cohort 2 n=8,500). The follow‐up period was from July 1st, 2009 to February 19th, 2010 (233 days). Intervention was voluntary waiting at home on full pay if the family became Influenza like Illness (ILI). The incidences of influenza A H1N1 and those of the subgroups whose families got ILI in both cohorts were compared by a Cox regression model and log‐rank test.

Results

There were 189 and 270 workers who got H1N1 infection during the follow‐up period in each cohort. In this period 317 workers in Cohort 1 were asked to wait at home for several days (100% obeyed). The intervention group (Cohort 1) showed a statistically significant lower risk (p for log‐rank test=0.033) compared with the control (Cohort 2), and the hazard ratio of the intervention was 0.799 [0.658–0.970] after adjusting for age, sex, BMI and smoking status. The workers who were asked to wait at home showed H1N1 infection more frequently (49 out of 317) compared with the workers whose family got ILI but were not asked to wait and work regularly (77 out of 990, RR=2.17 [1.48– 3.18]).

Conclusions

The waiting on full pay policy in the workplace reduced the overall risk of influenza A H1N1 by about 20% in one lu season in Japan. This kind of non‐vaccine measure will be a promising option in workplaces to control the next lu pandemic.
Prevention of perinatal depression and anxiety with periconceptional care
Authors: Erős Erika , Hajós Anett
Published: May 2011

In the public mind, pregnancy, childbirth and newborn care is one of the most wonderful living experiences. However, epidemiological studies have shown that the risks of psychiatric disorders in the perinatal period are multiplying. Pregnancy entails with dramatic physical, mental and social role changing. The birth is a big, irreversible life event, and it should also be nominated as “rite of passage”. This process represents a normative crisis during life, which needs new coping mechanisms to be developed. The stress and anxiety during the development of the fetus causes negative consequences in the short and long-term and it causes dangerous complications for the mother, too. During postpartum period, the incidence of major depression is approximately 15-20% that most frequently occurs within 6 months after birth but until the child is 2 years old it can develop any time. Serious risks of the postpartum depression are suicide and infanticide. In addition, it also represents serious teratogenic effects of cognitive and psychomotor development of children. It makes harder to recognize that the symptoms are largely the same as in any other stage of depression occurring during lifetime, but some of the symptoms compliant of normal pregnancy and the postpartum period. In addition, the majorities of women recognize heavily the problem and visit a doctor, because based of social expectations they should feel happiness. After the disclosure of risk factors and securing preventive conditions, preparing to be a mother is effective in prevention of development of perinatal depression. The effective therapy is primarily based on the coaching approach, and requires multi-directional approach. Orv. Hetil., 2011, 152, 903–908.
Spontaneous aortic rupture during pregnancy
Authors: Pánczél Zita , Sára Levente , Tóth Péter , Hubay Márta , Keller Éva , Langmár Zoltán , Pajor Attila
Published: May 2011

Aortic dissection is a rare entity. Half of the aortic dissection cases occur during pregnancy in women under the age of 40. The authors report a case of a multiparous woman at the third trimester of her sixth pregnancy, who died from a sudden and intractable cardiovascular shock. Autopsy revealed the dissection of the ascending aorta. The case is interesting, especially because in the pregnant woman’s family it was not the first sudden death during pregnancy. Authors review the relevant literature regarding the symptoms and the genetic basis of this rare but potentially lethal complication of pregnancy. Orv. Hetil., 2011, 152, 929–933.
Fatores de mortalidade na fase de ovo de Tuta absoluta em sistemas de produção orgânica e convencional de tomate
Authors: Medeiros Maria Alice de , Sujii Edison Ryoiti , Morais Helena Castanheira de
Published: May 2011

A traça-do-tomateiro Tuta absoluta (Meyrick) (Lep.: Gelechiidae) está sujeita a fatores de mortalidade bióticos como predadores e parasitoides e fatores abióticos como água da irrigação e da chuva que influenciam sua dinâmica populacional. O objetivo deste trabalho foi quantificar a importância desses fatores na sobrevivência de ovos da traça-do-tomateiro. Os experimentos foram desenvolvidos na Embrapa Hortaliças, de 1/8/2004 a 7/11/2005, em plantio de tomate e tomate consorciado em sistema orgânico e tomate em sistema convencional. As avaliações consistiram em: 1) coleta de ovos no campo em diferentes épocas do ciclo da cultura e sua incubação em laboratório até a emergência do parasitoide ou eclosão da lagarta; 2) exposição de ovos sentinelas no campo por 72 horas; 3) ovos marcados e acompanhados a cada 24 horas até eclosão das lagartas em campo. Ovos coletados no campo e incubados em laboratório mostraram que a mortalidade por Trichogramma sp. foi de 32%. A mortalidade dos ovos que permaneceram no campo (metodologia 2 e 3), evidenciaram que o parasitismo por Trichogramma sp. foi de 12% e que os predadores e o efeito mecânico da água produziram 36% de mortalidade dos ovos. Essa diferença revela que a permanência dos ovos no campo os expõe à competição com predadores e a mortalidade causada pelo efeito mecânico da água reduzindo o recrutamento de Trichogramma sp. Parasitoides de ovos, predadores generalistas associados à ação da água acarretaram maior mortalidade de T. absoluta em sistemas de produção orgânica de tomate.
Percepção ambiental dos produtores e qualidade do solo em propriedades orgânicas e convencionais
Authors: Kamiyama Araci , Maria Isabella Clerici de , Souza Daniel Costa Coelho de , Silveira Adriana Parada Dias da
Published: May 2011

O sistema orgânico de produção deve resultar na utilização mais racional dos recursos naturais, sobretudo do solo. Os produtores orgânicos devem adotar práticas conservacionistas, além de atender a outros princípios deste sistema de produção. Neste trabalho foram avaliadas as práticas de manejo e conservação do solo adotadas por produtores orgânicos e convencionais nas regiões dos municípios de Socorro (Serra da Mantiqueira e Mogiana) e Ibiúna, situados no Estado de São Paulo. O objetivo dessa pesquisa foi verificar o grau de adoção de práticas conservacionistas pelos produtores e avaliar a qualidade do solo na agricultura orgânica e convencional. Foi elaborado e aplicado um questionário, com visitas locais para verificação das práticas conservacionistas e ocorrência de erosão, em 30 propriedades. Os resultados foram expressos em índices indicadores de diversidade de uso do solo, atitude conservacionista, percepção de erosão e do impacto sobre os recursos hídricos. Foram também realizadas análises de atributos químicos, físicos e biológicos indicadores da qualidade do solo. Concluiu-se que os produtores orgânicos têm maior percepção quanto à atitude conservacionista e nas propriedades orgânicas há maior diversidade de cultivos, embora não haja maior diversidade geral de uso do solo. A produção orgânica de alface, em Ibiúna proporcionou maior atividade biológica no solo e maior colonização por fungos micorrízicos arbusculares. O sistema orgânico possui maiores teores de matéria orgânica e menores de potássio e não houve diferença entre os atributos físicos do solo dos sistemas orgânico e convencional.