bluuebunny/crossref_metadata_2025 huggingface dataset:
Helping Hand or Competition? The Moderating Influence of Perceived Upward Mobility on the Relationship Between Blended Workgroups and Employee Attitudes and Behaviors
Authors: George Elizabeth , Chattopadhyay Prithviraj , Zhang Lida L.
Published: February 2011

This study attempts to reconcile previous findings that show both positive and negative outcomes associated with blended workgroups (i.e., workgroups consisting of both temporary and standard workers). Specifically, we conceptualize temporary and standard work as part of a naturally occurring status hierarchy in organizations and propose that blended workgroups have opposing effects on employees depending on employees' perceptions of their potential for upward mobility in that organization. We combine research on the blended workforce with theorizing from social identity and self-categorization theories to propose that when employees perceive the potential for upward mobility to be high, the proportion of temporary workers in the group will be negatively related to employee attitudes and behaviors, and the relationship will be positive when perceived mobility is low. Furthermore, we hypothesize that this relationship will be mediated by the valence of employees' perceptions of their workgroup's prototype. We test our hypotheses on a sample of 124 temporary and standard research scientists in an Australian organization. The results show that workgroup composition and perceived mobility jointly influence workgroup identification and organization-based self-esteem, mediated by the valence of workgroup prototype; however, workgroup composition and perceived mobility directly influence organizational citizenship behavior unmediated by prototype valence.
Can Pharmacokinetic and Pharmacodynamic Principles Be Applied to the Treatment of Multidrug-Resistant Acinetobacter?
Authors: Cooper Travis W , Pass Steven E , Brouse Sara D , Hall Ronald G
Published: February 2011

OBJECTIVE:

To discuss treatment options that can be used for treatment of Acinetobacter infections.

DATA SOURCES:

A MEDLINE search (1966-November 2010) was conducted to identify English-language literature on pharmacotherapy of Acinetobacter and the bibliographies of pertinent articles. Programs and abstracts from infectious diseases meetings were also searched. Search terms included Acinetobacter, multidrug resistance, pharmacokinetics, pharmacodynamics, Monte Carlo simulation, nosocomial pneumonia, carbapenems, polymyxins, sulbactam, aminoglycosides, tetracyclines, tigecycline, rifampin, and fluoroquinolones.

DATA SELECTION AND DATA EXTRACTION:

All articles were critically evaluated and all pertinent information was included in this review.

DATA SYNTHESIS:

Multidrug resistant (MDR) Acinetobacter, defined as resistance to 3 or more antimicrobial classes, has increased over the past decade. The incidence of carbapenem-resistant Acinetobacter is also increasing, leading to an increased use of dose optimization techniques and/or alternative antimicrobials, which is driven by local susceptibility patterns. However, Acinetobacter infections that are resistant to all commercially available antibiotics have been reported. General principles are available to guide dose optimization of aminoglycosides, β-lactams, fluoroquinolones, and tigecycline for infections due to gram-negative pathogens. Unfortunately, data specific to patients with Acinetobacter infections are limited. Recent pharmacokinetic-pharmacodynamic information has shed light on colistin dosing. The dilemma with colistin is its concentration-dependent killing, which makes once-daily dosing seem like an attractive option, but its short postantibiotic effect limits a clinician's ability to extend the dosing interval. Localized delivery of antimicrobials is also an attractive option due to the ability to increase drug concentration at the infection site while minimizing systemic adverse events, but more data are needed regarding this approach.

CONCLUSIONS:

Increased reliance on dosage optimization, combination therapy, and localized delivery of antimicrobials are methods to pursue positive clinical outcomes in MDR Acinetobacter infections since novel antimicrobials will not be available for several years. Well-designed clinical trials with MDR Acinetobacter are needed to define the best treatment options for these patients.
Thienopyridines in Acute Coronary Syndrome
Authors: Goodwin Matthew M , Desilets Alicia R , Willett Kristine C
Published: February 2011

OBJECTIVE:

To evaluate the safety and efficacy of the thienopyridines in order to identify their current place in therapy for the treatment of acute coronary syndrome (ACS).

DATA SOURCES:

Literature was accessed through MEDLINE (1966-October 2010 week 1), EMBASE (1980–2010 week 40), and a bibliographic review of published articles using the search terms acute coronary syndrome, clopidogrel, and prasugrel. Articles were limited to clinical trials conducted in humans and published in the English language.

STUDY SELECTION AND DATA EXTRACTION:

Head-to-head clinical trials evaluating the safety and efficacy of the thienopyridines in patients with ACS were critically reviewed. Trials evaluating ticlopidine were excluded due to its limited clinical use.

DATA SYNTHESIS:

Thienopyridines are an integral part of the treatment of ACS. Prior to the approval of prasugrel, clopidogrel was considered the agent of choice due to safety concerns associated with ticlopidine. A randomized controlled trial comparing prasugrel and clopidogrel has demonstrated superior efficacy with prasugrel, and post hoc analyses suggest additional benefit with prasugrel is derived in patients with ST-segment elevation myocardial infarction and patients with diabetes. However, safety concerns exist linking prasugrel with an increased risk of bleeding, which diminishes its advantage in elderly patients, underweight patients, and those with a history of stroke. Pharmacokinetic and pharmacodynamic studies discussing differences in response variability, platelet inhibition, interactions with proton pump inhibitors, and genetic factors between the thienopyridines are numerous, although more clinical data are needed to determine clinical implications.

CONCLUSIONS:

Clinical trial data have suggested prasugrel is superior to clopidogrel at preventing ischemic events in patients with ACS undergoing percutaneous coronary intervention. However, this coincides with an increased risk of bleeding. Clinicians must carefully interpret the current evidence, including limitations in study design and pharmacologic differences between agents, in order to balance the risks and benefits as new data become available.
Epidemiologic Evaluation of Cardiovascular Risk in Patients Receiving Milnacipran, Venlafaxine, or Amitriptyline: Evidence from French Health Data
Authors: Mease Philip J , Zimetbaum Peter J , Duh Mei Sheng , Vekeman Francis , Guérin Annie , Boerstoel-Streefland Mariette , Jiang Wenjun , Lefebvre Patrick
Published: February 2011

BACKGROUND:

Milnacipran, a selective serotonin and norepinephrine reuptake inhibitor, is approved by the Food and Drug Administration for the management of fibromyalgia. It has been available for many years in several countries outside the US for the treatment of depression.

OBJECTIVE:

To conduct population-based analyses comparing the risk of serious cardiovascular (CV) events (eg, acute myocardial infarction, stroke, congestive heart failure) associated with treatment with milnacipran compared with venlafaxine and amitriptyline, 2 other commonly prescribed drugs that also inhibit reuptake of norepinephrine and serotonin.

METHODS:

Information from the French Thales electronic health record database from 2001 to 2007 was used. Patients with 1 or more prescriptions for milnacipran, venlafaxine, or amitriptyline; 180 or more days of continuous eligibility prior to the first prescription; and no prior CV event diagnoses during the 180-day baseline period were included. A retrospective, matched-cohort design was employed. The incidence rates of CV events between cohorts receiving milnacipran, venlafaxine, and amitriptyline were compared using unadjusted incidence rate ratio (IRR) and adjusted conditional IRR based on Poisson regression.

RESULTS:

We identified 4452 milnacipran-venlafaxine and 3761 milnacipran-amitriptyline matched pairs. The matched cohorts had similar baseline characteristics. The unadjusted IRRs of any CV events, comparing milnacipran with venlafaxine or amitriptyline, were 1.02 (95% CI 0.73 to 1.44) and 1.30 (95% CI 0.90 to 1.89), respectively. Adjusted IRRs confirmed the statistical similarity in the CV event risk between milnacipran and venlafaxine (adjusted IRR = 1.29, 95% CI 0.76 to 2.17) or amitriptyline (adjusted IRR = 1.06, 95% CI 0.59 to 1.89).

CONCLUSIONS:

This French population-based study found that the risk of CV events was not significantly different for patients receiving milnacipran versus those receiving venlafaxine or amitriptyline.
Role of unique basic residues in cytotoxic, antibacterial and antiparasitic activities of human eosinophil cationic protein
Authors: Singh Anubha , Batra Janendra K.
Published: February 2011

Eosinophil granule proteins, eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin are members of the RNase A superfamily, which play a crucial role in host defense against various pathogens as they are endowed with several biological activities. Some of the biological activities possessed by ECP have been attributed to its strong basic character. In the current study, we have investigated the role of five unique basic residues, Arg22, Arg34, Arg61, Arg77 and His64 of ECP in its catalytic, cytotoxic, antibacterial and antiparasitic activities. These residues were changed to alanine to generate single and double mutants. None of the selected residues was found to be involved in the RNase activity of ECP. The substitution of all five residues individually was detrimental for the cytotoxic, antibacterial and antiparasitic activities of ECP; however, mutation of Arg22 and Arg34 resulted in the most significant effects. The double mutants also had reduced biological activities. All ECP mutants that had significantly reduced toxicity also had reduced membrane destabilization activity. Our study demonstrates that Arg22, Arg34, Arg61, Arg77 and His64 of ECP are crucial for its membrane destabilization activity, which appears to be the underlying mechanism of its cytotoxic, antibacterial and antiparasitic activities.
CSF biomarkers in neurodegenerative diseases
Authors: Mattsson Niklas
Published: February 2011

Neurodegenerative diseases are major world wide causes of morbidity and mortality. They form a heterogeneous group of diseases, ranging from rare monogenic inherited errors of metabolism to common multi-factorial dementias. Major research efforts focus on the development of disease modifying drugs for neurodegenerative diseases. As a result, there follows a need for reliable tools for diagnosis, prognosis and monitoring of therapy. Processes in the brain can be monitored by analysis of cerebrospinal fluid (CSF). Several CSF biomarkers of pathological processes in the brain are now available. Such biomarkers may be used for both research and in the clinical setting. However, several difficult problems remain to be solved. More intensive collaboration between academia, industry and government is likely needed to develop treatments and biomarkers for neurodegenerative diseases. This article reviews the definitions, usage and current limitations of CSF biomarkers in this field.
Non-invasive prenatal diagnosis of trisomy 21 by reverse transcriptase multiplex ligation-dependent probe amplification
Authors: Deng Yan-Hua , Yin Ai-Hua , He Qiong , Chen Jia-Chang , He Yun-Shao , Wang Hua-Qiao , Li Ming , Chen Hua-Yun
Published: February 2011

Background: Obtaining fetal DNA or RNA by either chorionic villus sampling (CVS) or amniocentesis is currently, the gold standard prenatal diagnosis. However, these invasive procedures carry risk of miscarriage. A reliable method for non-invasive prenatal diagnosis (NIPD) has long been sought to reduce the risk of miscarriage.

Methods: Cell-free fetal RNA was extracted from the plasma of peripheral blood from 121 women 9–20 weeks of pregnancy. Five single nucleotide polymorphism (SNP) loci in PLAC4 gene were analyzed by reverse transcriptase multiplex ligation-dependent probe amplification (RT-MLPA), followed by capillary electrophoresis. Karyotype analysis was used for confirmation of prenatal diagnosis of trisomy 21.

Results: Of 121 samples, 23 were diagnosed with trisomy 21, 87 with normal ploidy, nine had all five SNP loci homozygous and two had one heterozygous SNP locus. Comparing with karyotype analysis, the diagnostic sensitivity and specificity of RT-MLPA were 92% and 100%, respectively.

Conclusions: RT-MLPA is a convenient and reliable method for the diagnosis of trisomy 21. We have shown that this method has good specificity, high sensitivity, and high throughput, making this technique applicable for NIPD in clinical practice.
Thyroxin overdose due to rheumatoid factor interferences in thyroid-stimulating hormone assays
Authors: Georges Agnès , Charrié Anne , Raynaud Sophie , Lombard Christine , Corcuff Jean-Benoît
Published: February 2011

Background: Immunoassays are susceptible to interferences by anti-hormone antibodies, heterophilic antibodies or rheumatoid factor (RF).

Methods: We report a case of levothyroxin overdose because of gross overestimation of thyroid-stimulating hormone (TSH) by chemiluminescent and IRMA assays. Alternate assays were performed and heterophilic antibodies blocking tubes were used.

Results: Analytical investigations revealed: i) non-linear concentrations of TSH after serum dilutions, ii) decreased TSH concentrations after removal of heterophilic antibodies, iii) appropriately decreased TSH concentrations in alternate TSH assays and iv) identification of increased concentrations of RF.

Conclusions: The presence of RF may be responsible for false determination of TSH concentrations preventing monitoring of TSH.
Hydrogen peroxide and supercritical carbon dioxide: a new bleaching stage for Eucalyptus kraft-O2 pulps
Authors: Francisco Roberta Pacheco , Colodette Jorge Luiz , da Silva Curvelo Antonio Aprigio
Published: February 2011

Kraft pulp is currently bleached largely by the elemental chlorine free (ECF) technology with oxygen, chlorine dioxide, and hydrogen as active agents. This technology brought about significant environmental improvements in relation to standard processes based on chlorine gas and hypochlorite, but there is still need for further improvements. This study presents a novel environmentally friendly bleaching stage – the so-called ‘hydrogen peroxide in supercritical carbon dioxide’, P(SC-CO2) – that can be adapted to current ECF bleaching processes, with preference in cases where hydrogen peroxide is already used. In this study, the P(SC-CO2) stage was evaluated as a replacement to the last peroxide stage of the D(EP)DP bleaching sequence and to the first peroxide stage of the D(EP)DP sequence, for an oxygen delignified eucalypt kraft-O2 pulp. The P(SC-CO2) stage was run with 0.5% hydrogen peroxide, at 15% consistency, 70°C, and 73 bar. The reaction time was 30 min. The performances of regular P stages and the new P(SC-CO2) stage were compared. Promising results were observed with the DEP(SC-CO2)DP sequence; the P(SC-CO2) decreased kappa number from 2.7 to 2.1, and the hexenuronic acid groups from 17.0 to 12.4 mmol kg-1. The P(SC-CO2) stage showed poor performance when applied in the D(EP)DP(SC-CO2) sequence. It is concluded that the process presents potential but requires further optimization to improve selectivity and efficiency.
Preparation and physical characterization of strongly swellable oligo(oxyethylene) lignin hydrogels
Authors: Passauer Lars , Fischer Klaus , Liebner Falk
Published: February 2011

Highly swellable, mechanically stable hydrogels were obtained by cross-linking different technical lignins with poly(ethylene) glycol diglycidyl ether (PEGDGE). The gelation time and the properties of the products can be controlled by the extent of pre-oxidation and the cross-linking conditions, namely the dynamic viscosity η*, storage and loss modulus (G′; G″), and loss factor tan δ. The highest free swelling capacities (FSC) of up to 50 g water per g xerogel were obtained from pre-oxidized pine kraft lignin Indulin® AT and spruce organosolv lignin. Dynamic rheological measurements confirmed the typical rheological behaviour of gel structures, i.e. a linear decrease of dynamic viscosity about three orders of magnitude within a frequency range of 0.08 and 20 s-1. The results furthermore revealed a good mechanical sturdiness of the cross-linked lignin hydrogels. Sandy soils supplemented with small quantities of the hydrogels were found to feature a significantly increased plant-available water content. Based on the observed effects, oligo(oxyethylene) lignins are promising materials with respect to a prolonged water retention in soils.
Brightness reversion of eucalyptus kraft pulp: Effect of carbonyl groups generated by hypochlorous acid oxidation
Authors: Zhou Zhen , Jääskeläinen Anna-Stiina , Adorjan Immanuel , Potthast Antje , Kosma Paul , Vuorinen Tapani
Published: February 2011

The impact of hypochlorous acid (HOCl) treatment on a fully bleached eucalyptus kraft pulp was studied with respect to the final brightness as well as the brightness reversion under humid ageing conditions. The carbonyl contents in the pulps were determined by the CCOA method where carbazole-9-carboxylic acid [2-(2-aminooxethoxy)-ethoxy] amide (CCOA) was applied as the carbonyl-selective fluorescence label. The molecular weight distribution of cellulose and hemicelluloses was analyzed as well. The amount of carbonyl groups in pulp was observed to increase significantly after the HOCl treatment, and the carbonyl distribution in pulp to shift towards the low molecular weight fraction. Plotting the carbonyl content against the post color number (PCN) of the pulps revealed a linear correlation. Additionally, the effect of the hemicellulose content was investigated, and alkaline extraction was applied to partially remove the hemicelluloses in pulp. These hemicellulose-poor samples showed a lower reactivity with hypochlorous acid and less brightness reversion at equal carbonyl content.
FT-IR imaging microscopy to localise and characterise simultaneous and selective white-rot decay within spruce wood cells
Authors: Fackler Karin , Stevanic Jasna S. , Ters Thomas , Hinterstoisser Barbara , Schwanninger Manfred , Salmén Lennart
Published: February 2011

Spruce wood that had been degraded by white-rot fungi (Trametes versicolororCeriporiopsis subvermispora)and suffered mass losses up to 17% was investigated by transmission Fourier transform infrared (FT-IR) imaging microscopy. A significant marker during incipient simultaneous white-rot (T. versicolor) was the cleavage of glycosidic bonds of polysaccharides that preceded their metabolisation. Simultaneous white-rot processes were also characterised by a relative decrease of the overall lignin content and a relative accumulation of wood polysaccharides. No early marker was found for selective white-rot (C. subvermispora) that removes mainly lignin by an oxidative process. This feature was detected only in wood samples exhibiting mass losses higher than 12%. Furthermore, it was shown, that simultaneous and selective white-rot processes were unevenly distributed within the wood samples but quite evenly distributed within single tracheids.
A Test Protocol to Quantify the Peel Resistance of Adhesive Applied Low Slope Roofing Specimens Subjected to Shear Loading
Authors: Baskaran A. , Wu J. , Tanaka H.
Published: February 2011

Adhesive Applied Roofing System (AARS)s are regaining popularity in the Canadian low slope application. AARSs use no fasteners. All components (e.g., steel deck, vapour barrier (if any), insulation board, cover board, base sheet, and cap sheet) are integrated using cold adhesives and presented as a new generation of Built-Up Roofs. As there are no metal fasteners, AARSs can offer an advantage of a reduction in the moisture migration and thermal bridges of the roof assemblies. Moisture in the roof envelope can lead generally to material deterioration, structural integrity problems, and the growth of mould. Even though AARSs have been in use, existing uplift standards do not certify them for wind uplift performances. A new project, the “Development of Wind Uplift Standard for Adhesive Applied Low Slope Roofing System,” has been initiated in collaboration with industries, universities, and government departments. The project has three major tasks: Experimental investigation, formulation of a numerical model, and development of wind design guide and standards. This paper documents a segment of the findings from this project. Under Task 1, investigations were completed by constructing over 600 specimens constructed using cold adhesives and examining the peel resistance of bonded roofing components through mechanical separation of bonded layers by applying shear forces. These specimens use the insulation and the cover board components exclusively because they are more vulnerable to peeling under shear forces. Based on this scrutiny, three key parameters; namely, peel position, peel angle, and specimen size were optimized. This paper presents the findings and development of a standardized test method to determine the peel resistance of AARS specimens.
DrosophilaAcyl-CoA Synthetase Long-Chain Family Member 4 Regulates Axonal Transport of Synaptic Vesicles and Is Required for Synaptic Development and Transmission
Authors: Liu Zhihua , Huang Yan , Zhang Yi , Chen Di , Zhang Yong Q.
Published: February 2011

Acyl-CoA synthetase long-chain family member 4 (ACSL4) converts long-chain fatty acids to acyl-CoAs that are indispensable for lipid metabolism and cell signaling. Mutations in ACSL4 cause nonsyndromic X-linked mental retardation. We previously demonstrated thatDrosophiladAcsl is functionally homologous to human ACSL4, and is required for axonal targeting in the brain. Here, we report thatDrosophila dAcslmutants exhibited distally biased axonal aggregates that were immunopositive for the synaptic-vesicle proteins synaptotagmin (Syt) and cysteine-string protein, the late endosome/lysosome marker lysosome-associated membrane protein 1, the autophagosomal marker Atg8, and the multivesicular body marker Hrs (hepatocyte growth factor-regulated tyrosine kinase substrate). In contrast, the axonal distribution of mitochondria and the cell adhesion molecule Fas II (fasciclin II) was normal. Electron microscopy revealed accumulation of prelysomes and multivesicle bodies. These aggregates appear as retrograde instead of anterograde cargos. Live imaging analysis revealed thatdAcslmutations increased the velocity of anterograde transport but reduced the flux, velocity, and processivity of retrograde transport of Syt-enhanced green fluorescent protein-labeled vesicles. Immunohistochemical and electrophysiological analyses showed significantly reduced growth and stability of neuromuscular synapses, and impaired glutamatergic neurotransmission indAcslmutants. The axonal aggregates and synaptic defects indAcslmutants were fully rescued by neuronal expression of human ACSL4, supporting a functional conservation of ACSL4 across species in the nervous system. Together, our findings demonstrate that dAcsl regulates axonal transport of synaptic vesicles and is required for synaptic development and function. Defects in axonal transport and synaptic function may account, at least in part, for the pathogenesis of ACSL4-related mental retardation.
A Subtraction Mechanism of Temporal Coding in Cerebellar Cortex
Authors: Kalmbach Brian E. , Voicu Horatiu , Ohyama Tatsuya , Mauk Michael D.
Published: February 2011

The temporally specific learning displayed by the cerebellum facilitates mechanistic analysis of neural timing and temporal coding. We report evidence for a subtraction-like mechanism of temporal coding in cerebellar cortex in which activity in a subset of granule cells specifically codes the interval between the offset of two mossy fiber inputs. In a large-scale cerebellar simulation, cessation of one of two ongoing mossy fiber inputs produces a robust temporal code in the population of granule cells. This activity supports simulation learning in response to temporal patterns of stimuli, even when those same stimuli do not support learning when presented individually. Using stimulation of mossy fiber inputs to the cerebellum as training stimuli in rabbits, we confirmed these unusual predictions in a cerebellum-dependent form of learning. Analysis of the simulations reveals a specific working hypothesis for this temporal subtraction process that involves interactions between granule cells and the inhibitory Golgi cells. The results suggest how feedforward inhibition, such as that present in the cerebellar cortex, can contribute to temporal coding.
Trigeminal Nociceptive Transmission in Migraineurs Predicts Migraine Attacks
Authors: Stankewitz Anne , Aderjan David , Eippert Falk , May Arne
Published: February 2011

Several lines of evidence suggest a major role of the trigeminovascular system in the pathogenesis of migraine. Using functional magnetic resonance imaging (fMRI), we compared brain responses during trigeminal pain processing in migraine patients with those of healthy control subjects. The main finding is that the activity of the spinal trigeminal nuclei in response to nociceptive stimulation showed a cycling behavior over the migraine interval. Although interictal (i.e., outside of attack) migraine patients revealed lower activations in the spinal trigeminal nuclei compared with controls, preictal (i.e., shortly before attack) patients showed activity similar to controls, which demonstrates that the trigeminal activation level increases over the pain-free migraine interval. Remarkably, the distance to the next headache attack was predictable by the height of the signal intensities in the spinal nuclei. Migraine patients scanned during the acute spontaneous migraine attack showed significantly lower signal intensities in the trigeminal nuclei compared with controls, demonstrating activity levels similar to interictal patients. Additionally we found—for the first time using fMRI—that migraineurs showed a significant increase in activation of dorsal parts of the pons, previously coined “migraine generator.” Unlike the dorsal pons activation usually linked to migraine attacks, the gradient-like activity following nociceptive stimulation in the spinal trigeminal neurons likely reflects a raise in susceptibility of the brain to generate the next attack, as these areas increase their activity long before headache starts. This oscillating behavior may be a key player in the generation of migraine headache, whereas attack-specific pons activations are most likely a secondary event.
Active Zones and the Readily Releasable Pool of Synaptic Vesicles at the Neuromuscular Junction of the Mouse
Authors: Ruiz Rocío , Cano Raquel , Casañas Juan José , Gaffield Michael A. , Betz William J. , Tabares Lucía
Published: February 2011

Synchronous neurotransmitter release is a highly regulated process that takes place at specializations at the presynaptic membrane called active zones (AZs). The relationships between AZs, quantal release, and vesicle replenishment are not well understood in a mature synapse. We have measured the number, distribution, and other properties of AZs in mouse motor nerve terminals and combined these observations with electrophysiological estimates of the size of the readily releasable pool (RRP) of synaptic vesicles. On average, we counted 850 AZs per terminal. Assuming two primary docked vesicles per AZ, we predict a total of ∼1700 vesicles optimally positioned for exocytosis. Electrophysiological estimates of the size of the RRP, using a simple kinetic model that assumes exponential depletion of the initial pool and refilling by recruitment, gave an average value of 1730 quanta during 100 Hz stimulation, in satisfying agreement with the morphology. At lower stimulus frequencies, however, the model revealed that the estimated RRP size is smaller, suggesting that not all AZs participate in release at low stimulation frequencies.
Fragile X Mental Retardation Protein Regulates New Neuron Differentiation in the Adult Olfactory Bulb
Authors: Scotto-Lomassese Sophie , Nissant Antoine , Mota Tatiana , Néant-Féry Marie , Oostra Ben A. , Greer Charles A. , Lledo Pierre-Marie , Trembleau Alain , Caillé Isabelle
Published: February 2011

The fragile X mental retardation protein (FMRP) is an RNA-binding protein essential for multiple aspects of neuronal mRNA metabolism. Its absence leads to the fragile X syndrome, the most prevalent genetic form of mental retardation. The anatomical landmark of the disease, also present in theFmr1knock-out (KO) mice, is the hyperabundance of immature-looking lengthened dendritic spines. We used the well known continuous production of adult-born granule cells (GCs) in the mouse olfactory bulb (OB) to analyze the consequences of Fmrp loss on the differentiation of GCs. Morphological analysis of GCs in theFmr1KO mice showed an increase in spine density without a change in spine length. We developed an RNA interference strategy to cell-autonomously mutateFmr1in a wild-type OB network. Mutated GCs displayed an increase in spine density and spine length. Detailed analysis of the spines through immunohistochemistry, electron microscopy, and electrophysiology surprisingly showed that, despite these abnormalities, spines receive normal glutamatergic synapses, and thus that mutated adult-born neurons are synaptically integrated into the OB circuitry. Time-course analysis of the spine defects showed that Fmrp cell-autonomously downregulates the level and rate of spine production and limits their overgrowth. Finally, we report that Fmrp does not regulate dendritogenesis in standard conditions but is necessary for activity-dependent dendritic remodeling. Overall, our study of Fmrp in the context of adult neurogenesis has enabled us to carry out a precise dissection of the role of Fmrp in neuronal differentiation and underscores its pleiotropic involvement in both spinogenesis and dendritogenesis.
Akt Suppresses Retrograde Degeneration of Dopaminergic Axons by Inhibition of Macroautophagy
Authors: Cheng Hsiao-Chun , Kim Sang Ryong , Oo Tinmarla F. , Kareva Tatyana , Yarygina Olga , Rzhetskaya Margarita , Wang Chuansong , During Matthew , Talloczy Zsolt , Tanaka Keiji , Komatsu Masaaki , Kobayashi Kazuto , Okano Hideyuki , Kholodilov Nikolai , Burke Robert E.
Published: February 2011

Axon degeneration is a hallmark of neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Such degeneration is not a passive event but rather an active process mediated by mechanisms that are distinct from the canonical pathways of programmed cell death that mediate destruction of the cell soma. Little is known of the diverse mechanisms involved, particularly those of retrograde axon degeneration. We have previously observed in living animal models of degeneration in the nigrostriatal projection that a constitutively active form of the kinase, myristoylated Akt (Myr-Akt), demonstrates an ability to suppress programmed cell death and preserve the soma of dopamine neurons. Here, we show in both neurotoxin and physical injury (axotomy) models that Myr-Akt is also able to preserve dopaminergic axons due to suppression of acute retrograde axon degeneration. This cellular phenotype is associated with increased mammalian target of rapamycin (mTor) activity and can be recapitulated by a constitutively active form of the small GTPase Rheb, an upstream activator of mTor. Axon degeneration in these models is accompanied by the occurrence of macroautophagy, which is suppressed by Myr-Akt. Conditional deletion of the essential autophagy mediatorAtg7in adult mice also achieves striking axon protection in these acute models of retrograde degeneration. The protection afforded by both Myr-Akt andAtg7deletion is robust and lasting, because it is still observed as protection of both axons and dopaminergic striatal innervation weeks after injury. We conclude that acute retrograde axon degeneration is regulated by Akt/Rheb/mTor signaling pathways.
Lyn Kinase Regulates Mesolimbic Dopamine Release: Implication for Alcohol Reward
Authors: Gibb Stuart L. , Jeanblanc Jerome , Barak Segev , Yowell Quinn V. , Yaka Rami , Ron Dorit
Published: February 2011

We report here that the Src family tyrosine kinase Lyn negatively regulates the release of dopamine (DA) in the mesolimbic system, as well as the rewarding properties of alcohol. Specifically, we show that RNA interference-mediated knockdown of Lyn expression results in an increase in KCl-induced DA release in DAergic-like SH-SY5Y cells, whereas overexpression of a constitutively active form of Lyn (CA-Lyn) leads to a decrease of DA release. Activation of ventral tegmental area (VTA) DAergic neurons results in DA overflow in the nucleus accumbens (NAc), and we found that the evoked release of DA was higher in the NAc of Lyn knock-out (Lyn KO) mice compared with wild-type littermate (Lyn WT) controls. Acute exposure of rodents to alcohol causes a rapid increase in DA release in the NAc, and we show that overexpression of CA-Lyn in the VTA of mice blocked alcohol-induced (2 g/kg) DA release in the NAc. Increase in DA levels in the NAc is closely associated with reward-related behaviors, and overexpression of CA-Lyn in the VTA of mice led to an attenuation of alcohol reward, measured in a conditioned place preference paradigm. Conversely, alcohol place preference was increased in Lyn KO mice compared with Lyn WT controls. Together, our results suggest a novel role for Lyn kinase in the regulation of DA release in the mesolimbic system, which leads to the control of alcohol reward.
Lesions of the Basolateral Amygdala and Orbitofrontal Cortex Differentially Affect Acquisition and Performance of a Rodent Gambling Task
Authors: Zeeb Fiona D. , Winstanley Catharine A.
Published: February 2011

Risky decision making on the Iowa Gambling Task (IGT) has been observed in several psychiatric disorders, including substance abuse, schizophrenia, and pathological gambling. Such deficits are often attributed to impaired processing within the orbitofrontal cortex (OFC) because patients with damage to this area or to the amygdala, which is strongly interconnected with the OFC, can likewise show enhanced choice of high-risk options. However, whether damage to the OFC or amygdala impairs subjects' ability to learn the task, or actually affects the decision-making process itself, is currently unclear. To address these issues, rats were trained to perform a rodent gambling task (rGT) either before or after bilateral excitotoxic lesions to the basolateral amygdala (BLA) or OFC. Maximum profits in both the rGT and IGT are obtained by favoring smaller rewards associated with lower penalties, and avoiding the tempting, yet ultimately disadvantageous, large reward options. Lesions of the OFC or BLA made before task acquisition initially impaired animals' ability to determine the optimal strategy, but did not disrupt decision making in the long term. In contrast, lesions of the BLA, but not the OFC, made after the task had been acquired increased risky choice. These results suggest that, although both regions contribute to the development of appropriate choice behavior under risk, the BLA maintains a more fundamental role in guiding these decisions. The maladaptive choice pattern observed on the IGT in patients with OFC lesions could therefore partially reflect a learning deficit, whereas amygdala damage may give rise to a more robust decision-making impairment.
Glenn Ligon and Other Runaway Subjects
Authors: Copeland Huey
Published: February 2011

In this essay, Huey Copeland examines contemporary artist Glenn Ligon's multiple engagements with the history of American slavery, particularly as evidenced by his 1993 installation To Disembark. As Copeland shows, in casting himself as a runaway slave, Ligon points up the relationships between the regimes of power, violence, and resistance that continue to produce black subjects as fugitives in life and in representation.
Genetics Behind Barbed Wire: Masuo Kodani, Émigré Geneticists, and Wartime Genetics Research at Manzanar Relocation Center
Authors: Smocovitis Vassiliki Betty
Published: February 2011

This article explores the sociopolitical backdrop of genetics research during the politically turbulent decades of the mid-20th century that saw the persecution, displacement, and relocation of unpopular minorities in both the United States and Europe. It explores how geneticists in the United States accommodated these disruptions through formal and informal émigré networks and how the subsequent war affected their research programs and their lives. It does so by focusing on the career and life of geneticist Masuo Kodani, who, as a Japanese American, found himself conducting unexpected cytogenetics research in Manzanar, a “relocation center,” or internment camp, located in the California desert, after the attack on Pearl Harbor. After the war, Kodani's subsequent career continued to be shaped by his experiences as a Japanese American and by the specific skills as a cytogeneticist that he demonstrated at a critical period in the history of 20th-century genetics. His many relocations in search of employment culminated in his work with the Atomic Bomb Casualty Commission on human chromosomes, for which he is best known.
Job Stress and Mental Health of Permanent and Fixed‐term Workers Measured by Effort‐reward Imbalance Model, Depressive Complaints, and Clinic Utilization
Authors: Inoue Mariko , Tsurugano Shinobu , Yano Eiji
Published: February 2011

Job Stress and Mental Health of Permanent and Fixed‐term Workers Measured by Effort‐reward Imbalance Model, Depressive Complaints, and Clinic Utilization: Mariko Inoue, et al. Department of Hygiene and Public Health, School of Medicine, Teikyo University—

Objectives

The number of workers with precarious employment has increased globally; however, few studies have used validated measures to investigate the relationship of job status to stress and mental health. Thus, we conducted a study to compare differential job stress experienced by permanent and ixed‐term workers using an effort– reward imbalance (ERI) model questionnaire, and by evaluating depressive complaints and clinic utilization.

Methods

Subjects were permanent or ixed‐term male workers at a Japanese research institute (n=756). Baseline data on job stress and depressive complaints were collected in 2007. We followed up with the same population over a 1‐year period to assess their utilization of the company clinic for mental health concerns.

Results

The ERI ratio was higher among permanent workers than among fixed‐term workers. More permanent workers presented with more than two depressive complaints, which is the standard used for the diagnosis of depression. ERI scores indicated that the effort component of permanent work was associated with distress, whereas distress in ixed‐term work was related to job promotion and job insecurity. Moreover, over the one‐year follow‐up period, ixed‐term workers visited the on‐site clinic for mental concerns 4.04 times more often than permanent workers even after adjusting for age, lifestyle, ERI, and depressive complaints.

Conclusions

These contrasting indings reflect the differential workloads and working conditions encountered by permanent and ixed‐term workers. The occupational setting where employment status was intermingled, may have contributed to the high numbers of mental health‐related issues experienced by workers with different employment status.
Population Composition, Migration Timing, and Harvest of Columbia River Chinook Salmon in Late Summer and Fall
Authors: Jepson M. A. , Keefer M. L. , Naughton G. P. , Peery C. A. , Burke B. J.
Published: February 2011

We used radiotelemetry to evaluate population composition, run timing, and reservoir harvest patterns for adult Columbia River fall-run Chinook salmon Oncorhynchus tshawytscha. Chinook salmon (n = 5,886) were collected at Bonneville Dam during August–October over 7 years. We selected for upriver bright (URB) populations en route to interior basin spawning sites because these groups are priority populations for both fisheries and conservation efforts. Run composition varied within and among years, but in all years a relatively large percentage of the earliest migrants returned to upper Columbia River sites and the majority of late-run fish returned to the Columbia River Hanford Reach. Deschutes, Yakima, and Snake River populations typically constituted small (≤17%) but relatively constant proportions of the run throughout each migration season. Population-specific migration timing distributions indicated modest but persistent timing differences among populations, particularly for Hanford Reach and upper Columbia River populations. Annual reported reservoir harvest estimates ranged from 12% to 26%. Harvest rates varied seasonally within years, from relatively low mean rates (≤11%) for fish tagged early and late in migrations to peak rates of over 25% for those tagged in late August and early September. These patterns suggest that it may be possible to increase harvest of abundant populations and reduce harvest of some vulnerable populations by adjusting the timing of fisheries. In addition, there was evidence that larger fish were harvested at higher rates and that mean fish size differed among populations. The combined results improve our understanding of the Columbia River URB fall Chinook salmon run and should help in refining harvest and escapement management plans.
Smallmouth Bass Summer Habitat Use, Movement, and Survival in Response to Low Flow in the Illinois Bayou, Arkansas
Authors: Hafs Andrew W. , Gagen Charles J. , Whalen J. Keith
Published: February 2011

The southwestern edge of the natural range of smallmouth bass Micropterus dolomieu contains streams that become disconnected pools during summer primarily owing to hydrogeologic conditions, including high evapotranspiration rates. These conditions may complicate fisheries management by affecting fish behavior or mortality rates. The objectives of this study were to characterize summer habitat use by smallmouth bass, estimate the changes in the extent of available habitat, describe summer movement patterns, and estimate summer survival rates. Radio transmitters were implanted into 60 smallmouth bass during May 2006, and the fish were tracked until October in the forks of the Illinois Bayou, which drains a portion of the Ozark National Forest. Habitat characteristics were measured as the summer progressed, and during this time most riffle–run habitat dried completely, resulting in a series of disconnected pools. The decreases in wetted area exceeded 55% in certain 2-km study reaches; however, smallmouth bass were consistently found at a median depth of 0.80 m. Boulder habitat was preferred when it was available; however, cobble, gravel, and bedrock substrates were also used. By July, velocity was below detection levels and water temperature occasionally exceeded 30°C. The average distance moved by smallmouth bass was 270 m in May, decreasing to 54 m by July. The distances moved were greater on average but more variable in streams with larger losses of wetted area, as fish moved away from drying areas. The survival rate was lowest in the stream most accessible to anglers. Dryness appeared to increase mortality, as survival estimates were lower than expected from published studies of streams with continuous summer flow. The effective management of fisheries under such hydrologic conditions may require preserving continuous surface flow and the quality of remnant pools as well as implementing more restrictive harvest regulations in summer.
Proximate Composition and Fatty Acid Differences in Hatchery-Reared and Wild Snake River Sockeye Salmon Overwintering in Nursery Lakes
Authors: Powell M. S. , Hardy R. W. , Flagg T. A. , Kline P. A.
Published: February 2011

In the artificial propagation program for endangered Snake River sockeye salmon Oncorhynchus nerka, a portion of the F1 progeny (produced from spawning captive parents) are retained in the hatchery through maturation and spawning; the remaining progeny are reintroduced to nursery lakes in central Idaho at several life history stages (egg, presmolt, and smolt). In this study, the proximate and fatty acid compositions of sockeye salmon from presmolt releases were analyzed both at planting and at out-migration to assess their feeding success after overwintering in nursery lakes relative to that of overwintering wild fish. Hatchery-origin presmolts did not grow significantly over the winter. However, size and length were similar between hatchery-origin fish and wild out-migrants. Average percent whole-body lipid declined significantly in hatchery-origin sockeye salmon overwinter. Hatchery-origin out-migrants also had significantly lower whole-body lipid than wild counterparts migrating from Redfish Lake, Idaho, over the 6 years examined. The lack of growth and significantly lower body fat content of hatchery-origin sockeye salmon suggest that the food resources available to both wild and hatchery-origin presmolts were not utilized equally. There were also significant differences in fatty acid composition between wild and hatchery-origin out-migrants. Wild out-migrants had fatty acid profiles indicative of the zooplankton diet typical of resident sockeye salmon in the lake. In contrast, hatchery-reared juveniles introduced as presmolts in the fall had fatty acid profiles resembling those associated with hatchery diets and showed no evidence of the fatty acids characteristically observed in zooplankton. After overwintering, hatchery-origin out-migrants had fatty acid profiles that were intermediate between those of fish at planting and those of wild fish, reflecting some zooplankton intake during this period. The compromise in lipid quantity and quality for hatchery-produced presmolts may, in part, explain the large observed reductions in smolt-to-adult survival relative to that of naturally produced sockeye salmon.
Associations between Watershed Characteristics and Angling Success for Sport Fishes in Mississippi Wadeable Streams
Authors: Alford J. Brian , Jackson Donald C.
Published: February 2011

We developed and evaluated multiple linear regression models to describe the associations between watershed land use and geomorphology and angling success (catch per unit effort [CPUE; fish/h]) for sport fishes in wadeable streams in Mississippi. The mean angler CPUE for all species combined, sunfishes Lepomis spp., and black bass Micropterus spp. was strongly and positively associated with the percentage of forest cover, stream density, total road density, and primary highway density. The mean angler CPUE of largemouth bass M. salmoides and longear sunfish L. megalotis was negatively associated with the percentage of agricultural land but positively associated with rural road density. The mean CPUE of spotted bass M. punctulatus was negatively associated with elevation and the number of road crossings in the watershed but positively associated with rural road density. Model validation procedures revealed that the prediction errors were relatively large, so that the ability to predict mean angler CPUE from individual streams was low for all models. However, the species group models were precise, explaining 83, 71, and 80%, respectively, of the variation in the mean CPUE for all species, sunfishes, and black bass from an independent data set. In contrast, the species-specific models were relatively imprecise, explaining less than 33% of the variation in the mean CPUE in the independent data. We advocate a landscape-level management perspective—in concert with more traditional assessments of water quality and biological integrity—to address the connection between sport fishing and conservation in wadeable streams in Mississippi.