bluuebunny/crossref_metadata_2025_split huggingface dataset:
Involvement of the lateral orbitofrontal cortex in drug context‐induced reinstatement of cocaine‐seeking behavior in rats
Authors: Lasseter Heather C. , Ramirez Donna R. , Xie Xiaohu , Fuchs Rita A. 
Published: September 2009

AbstractOrbitofrontal cortex (OFC) damage produces impaired decision‐making, impulsivity and perseveration and potentially contributes to compulsive drug seeking in cocaine users. To further explore this phenomenon, we assessed the role of the lateral OFC (lOFC) in drug context‐induced cocaine‐seeking behavior in the reinstatement model of drug relapse. Rats were trained to lever press for intravenous cocaine infusions in a distinct environmental context (cocaine‐paired context) followed by extinction training in a different context (extinction‐paired context). Reinstatement of cocaine seeking (non‐reinforced lever presses) was assessed in the cocaine context in the absence of response‐contingent stimuli. In Experiment 1, we evaluated whether acute inhibition of lOFC output alters context‐induced cocaine‐seeking behavior by infusing the GABAB + A agonists (baclofen + muscimol) or vehicle into the lOFC immediately before exposure to the cocaine‐paired context. In Experiments 2 and 3, we assessed how prolonged loss of lOFC output affects drug context‐induced cocaine seeking by administering bilateral N‐methyl‐d‐aspartic acid or sham lesions of the lOFC either before or after self‐administration and extinction training. Remarkably, IOFC functional inactivation attenuated, post‐training lesions failed to alter and pre‐training lesions potentiated drug context‐induced cocaine seeking without altering responding in the extinction context. These results suggest that neural activity in the lOFC promotes context‐induced cocaine‐seeking behavior. However, prolonged loss of lOFC output enhances the motivational salience of cocaine‐paired contextual stimuli probably by eliciting compensatory neuroadaptations, with the effects of post‐training lOFC lesions reflecting an intermediate state of compensatory neuroplasticity. Overall, these findings support the idea that OFC dysfunction may promote cue reactivity and enhance relapse propensity in cocaine users.
Cocaine‐induced stereotypy is linked to an imbalance between the medial prefrontal and sensorimotor circuits of the basal ganglia
Authors: Aliane Verena , Pérez Sylvie , Nieoullon André , Deniau Jean‐Michel , Kemel Marie‐Louise 
Published: September 2009

AbstractThe dysfunction of basal ganglia circuits related to stereotyped motor activity was analysed using the well‐established model of cocaine‐induced stereotypy in the rat. We examined and compared the neurochemical and electrophysiological effects occurring in medial prefrontal and sensorimotor basal ganglia circuits of the dorsal striatum after cocaine injection in sensitized and non‐sensitized rats. Acute injections of cocaine (25 mg/kg), not inducing stereotyped behaviour, affected both medial prefrontal and sensorimotor circuits in a similar way: (i) a mild and delayed increase and decrease of N‐methyl‐D‐aspartate‐evoked dopamine and acetylcholine release, respectively and (ii) a marked decrease of cortically evoked inhibition of substantia nigra pars reticulata neurons revealing an imbalance of information transmission between the direct and indirect trans‐striatal pathways. In contrast, following sensitization to cocaine, a challenge injection of the same dose of cocaine, generating strong stereotyped behaviour, provoked neurochemical and electrophysiological effects only in the medial prefrontal but not in the sensorimotor circuits: (i) a strong increase of dopamine and decrease of acetylcholine release in the medial prefrontal territory of the dorsal striatum and (ii) a reduction of all inhibitory and excitatory components of the responses evoked in substantia nigra pars reticulata by medial prefrontal stimulation. Therefore, these data disclose distinct reactivity of the medial prefrontal and sensorimotor circuits of the basal ganglia to repeated cocaine administration leading to stereotyped behaviour induced by subsequent cocaine challenge. Thus, we suggest that stereotyped behaviour is correlated to an imbalance between the medial prefrontal and sensorimotor circuits of the basal ganglia resulting in a loss of control of motor behaviour.
Oxytocin injected into the ventral subiculum or the posteromedial cortical nucleus of the amygdala induces penile erection and increases extracellular dopamine levels in the nucleus accumbens of male rats
Authors: Melis Maria Rosaria , Succu Salvatora , Sanna Fabrizio , Boi Antonio , Argiolas Antonio 
Published: September 2009

AbstractOxytocin (20–100 ng) was found to be able to induce penile erection when injected unilaterally into the ventral subiculum or the posteromedial cortical nucleus of the amygdala of male rats. The pro‐erectile effect started mostly 30 min after treatment and was abolished by the prior injection of d(CH2)5Tyr(Me)2‐Orn8‐vasotocin (1–2 μg), an oxytocin receptor antagonist, into the ventral subiculum or posteromedial cortical nucleus. Oxytocin‐induced penile erection occurred 15 min after the increase in the concentration of extracellular dopamine and its metabolite 3,4‐dihydroxyphenylacetic acid in the dialysate obtained from the nucleus accumbens, which was also abolished by d(CH2)5Tyr(Me)2‐Orn8‐vasotocin. The pro‐erectile effect of oxytocin was also reduced bycis‐flupentixol (2 and 5 μg), a dopamine receptor antagonist, injected into the nucleus accumbens, and by (+)MK‐801 (5 μg), a noncompetitiveN‐methyl‐d‐aspartate receptor antagonist, injected into the ventral tegmental area, but not into the nucleus accumbens. Together with studies showing that glutamatergic efferents from the ventral subiculum/posteromedial cortical nucleus of the amygdala to other areas of the limbic system modulate the activity of mesolimbic dopaminergic neurons, these findings suggest that oxytocin injected into these areas increases glutamatergic neurotransmission in the ventral tegmental area. This, in turn, activates mesolimbic dopaminergic neurons, leading to penile erection. These results provide evidence that the ventral subiculum and the posteromedial cortical nucleus of the amygdala participate in a neural circuit that controls not only the consummatory aspects of sexual behaviour (e.g. penile erection and copulatory performance), but also its motivational/reward aspects, confirming a key role of oxytocin and dopamine in these processes.
Depolarization amplitude and Ca2+‐inflow control the time course of quantal releases at murine motor nerve terminals
Authors: Dudel Josef 
Published: September 2009

AbstractIn order to test whether the time courses of quantal releases after a depolarization pulse are affected by the depolarization amplitude, time courses were measured for small depolarization pulses that elicited close to threshold releases and for large depolarizations that elicited releases approaching saturation level. Diaphragms of young mice were excised and superfused with Bretag’s solution at 18°C. Synaptic currents were elicited and recorded through a perfused macropatch pipette. Releases elicited by threshold depolarizations rose earlier than releases elicited by saturation depolarizations. The short delays in the rising phases of release after large depolarizations may be due to the shift of Ca2+ currents flowing during the pulse to tail currents. After its peak, release decayed with a time constant τ. For saturation depolarizations τ was about 0.3 ms, and for threshold depolarizations τ increased up to 0.8 ms. In order to differentiate between the effects of variations in Ca2+ inflow and in depolarization, the amplitudes of large depolarization pulses were held constant while the amount of release was depressed by halving the Ca2+ concentration at the terminal. The time course of the lowered releases was slightly delayed while τ remained at 0.3 ms as typical for saturation depolarizations. Double pulse facilitation unexpectedly revealed a short phase of depression of release after the pulse. This depression may contribute to the rapid decay (τ) of release after large depolarizations. The dependence of τ on depolarization amplitude indicates that the final phase of the time course of release is largely controlled by the amplitude of the preceding depolarization.
Political Skill, Supervisor–Subordinate Guanxi and Career Prospects in Chinese Firms
Authors: Wei Li‐Qun , Liu Jun , Chen Yuan‐Yi , Wu Long‐Zeng 
Published: September 2009

abstractThe role of political skill was examined in the dynamics of supervisor–subordinate relationship in Chinese firms. Data from a survey of 343 employees, their 343 direct supervisors, and 662 of their peers were applied to test a model proposing that Chinese subordinates employ political skill to influence their guanxi with their supervisors, and so promote their career development. We found that supervisor–subordinate guanxi mediated the relationship between political skill and career development of the subordinates. Implications of the findings were discussed.
A Study of the Association between Level of Slack Reduction Following Downsizing and Innovation Output
Authors: Mellahi Kamel , Wilkinson Adrian 
Published: September 2009

abstractOver the years scholars put forward a number of theories to explain the association between slack and innovation. This study extends this body of research by focusing on the effects of reduction in slack level following downsizing on innovation output. We developed two hypotheses to examine the total effects and varied yearly effects. We tested the hypotheses with data from a panel of UK firms that downsized between 1997 and 2003. The results show that the level of downsizing has only temporary effects on innovation output. We discuss the implications of these findings and avenues for future research.
Stochastic efficiency analysis with risk aversion bounds: a correction
Authors: Meyer Jack , Richardson James W. , Schumann Keith D. 
Published: September 2009

A recent paper by Hardaker et al. (The Australian Journal of Agricultural and Resource Economics, 48, 2004a, 253) and book by Hardaker et al. (Coping with Risk in Agriculture, 2004b) describe a procedure for determining an efficient set from among a set of random alternatives. This procedure, called stochastic efficiency with respect to a function (SERF), is claimed to make the same assumption concerning the risk aversion measures as does stochastic dominance with respect to a function (SDRF). This is claim is incorrect. SERF imposes an additional requirement on the risk aversion measures of the decision makers. Both procedures assume a lower and an upper bound on risk aversion, but SERF also assumes that all risk aversion measures are of the same functional form as these lower and upper bound functions. This additional strong requirement on risk preferences implies that the efficient set identified under SERF is usually smaller than that identified using SDRF.
Migrant Rights: International Law and National Action
Authors: Martin Susan , Abimourched Rola 
Published: September 2009

AbstractMigrant rights were put squarely on the agenda of the Global Forum on Migration and Development when it met in Manila in 2008, as the principal theme of the governmental and civil society discussions. The Forum proceeded with the assumption that migrant rights are a development issue, as well as a fundamental human rights issue. This article begins with a review of the normative framework for protecting migrant rights. While norms by themselves will not prevent abuses, they can serve as a basis for advocating implementation of policies and programs to achieve these goals. We argue that there is ample international law setting out the basic rights of migrants even though the principal migrant‐centric instruments are not widely ratified. Failures in protecting migrant rights arise from the lack of implementation of these standards at the national level. The article then discusses a range of programs, mostly implemented by or in destination countries, which hold potential for overcoming barriers to the protection of the rights of migrants. These practical steps can be found in a wide array of countries, most of which have not become party to the Migrant Workers Convention. The article concludes that these initiatives have been implemented in an ad hoc manner, necessitating a more systematic approach at the national level to the protection of migrant rights.
The influence of sex on the course and psychiatric correlates of ADHD from childhood to adolescence: A longitudinal study
Authors: Monuteaux Michael C. , Mick Eric , Faraone Stephen V. , Biederman Joseph 
Published: September 2009

Background:  Little is known about the influence of sex on the course of attention‐deficit/hyperactivity disorder (ADHD) and its comorbid psychiatric conditions. The purpose of this study was to examine the effect of sex on the course and psychiatric correlates of ADHD from childhood into adolescence.Methods:  Two identically designed, longitudinal, case–control family studies of male and female probands with and without ADHD and their siblings were combined. All subjects were blindly assessed with structured diagnostic interviews. Among subjects with a lifetime history of ADHD (n = 471, mean age 11.5 ± 4.3 years at baseline), we used linear growth curve models to estimate the effect of time on the change in ADHD symptoms, and whether this effect differed by sex. We also we examined the effect of sex on the association between ADHD and the longitudinal progression of comorbid psychopathology using structural equation models.Results:  We found no evidence that sex moderated the effect of age on ADHD symptoms; in both genders, age exhibited a similar effect on the decline of ADHD symptoms. However, the female sample demonstrated greater stability in comorbid psychopathology from childhood into adolescence. Furthermore, we found that the stability of comorbid psychopathology in females remained significant after accounting for the correlation between adolescent psychopathology and adolescent ADHD. In males, childhood and adolescent comorbid psychopathology were no longer correlated when adolescent ADHD was taken into account.Conclusions:  Our findings indicate that while the course of ADHD across childhood and adolescence did not differ between males and females, patterns of psychiatric comorbidity were conditional on sex. Future studies should explicitly test how sex modifies the associations between ADHD and risk factors and ADHD and associated functional outcomes.
Historical Changes in Ponderosa Pine Forests Since Euro‐American Settlement
Authors: Rapport David J. 
Published: September 2009

ABSTRACTMost ecosystems require periodic disturbances to maintain their integrity, and human modification of natural disturbance regimes (e.g. fire frequency) often leads to deleterious changes. Ponderosa pine (Pinus ponderosaP. & C. Lawson) forests in the western United States are selected as examples. They were maintained in an open, park‐like condition because of frequent low‐intensity disturbances: fires and/or pest outbreaks. Fires enhanced grass cover, helped to reduce the buildup of organic matter, eliminated weak trees, and controlled pests. Euro‐American settlement changed this balance by allowing heavy livestock grazing, which caused damage to the grass cover and contributed to soil erosion and depletion of the nutrient pool. Later, the policy of fire suppression promoted the establishment of a greater density of ponderosa pine and understory thickets at the expense of the grasses and caused excessive accumulation of coarse organic matter. Productivity of the forest subsequently declined and the thickets stagnated. Today, even unlogged ponderosa pine forests exhibit profound signs of stress: slow production and growth, decreased rate of nutrient cycling, simplified vertical and horizontal structure, and increased extent of disease. Some ecosystem services, such as the provision of soil and water quality, high biodiversity, and aesthetic value, are impaired.
Logical Interrelations between Four Sustainability Parameters: Stability, Continuation, Longevity, and Health
Authors: Patten Bernard C. , Costanza Robert 
Published: September 2009

ABSTRACTThis paper investigates the logical interrelations between four properties that may be useful in understanding different aspects of sustainability and making it a more operational and useful concept. These properties are system stability, continuation, longevity, and health (integrity). The principal findings are as follows: (1) Stability is necessary but not sufficient for sustainability, continuation, longevity, and health. (2) Continuation is (a) sufficient but not necessary for sustainability, stability, and health and (b) both sufficient and necessary for longevity. (3) Longevity is (a) sufficient and necessary for sustainability and continuation and (b) sufficient but not necessary for stability and health. (4) Health is (a) necessary but not sufficient for sustainability, continuation, and longevity and (b) sufficient but not necessary for stability. (5) Sustainability itself is (a) sufficient but not necessary for stability and health; (b) necessary but not sufficient for continuation; and (c) both sufficient and necessary for longevity. These logical interrelations indicate that sustainability is not a simple concept but is related to others, some of which may provide useful measures for different applications. It seems important to explore formally the many dimensions of sustainability to build a precise concept for scientific use. The four attributes investigated here do not exhaust the possibilities.
Initial Experience of Pacing with a Lumenless Lead System in Patients with Congenital Heart Disease
Authors: CHAKRABARTI SANTABHANU , MORGAN GARETH J. , KENNY DAMIEN , WALSH KEVIN P. , OSLIZLOK PAUL , MARTIN ROBIN P. , TURNER MARK S. , STUART A. GRAHAM 
Published: September 2009

Background: Long‐term pacing is frequently necessary in patients with congenital heart disease (CHD). Preservation of ventricular function and avoidance of venous occlusion is important in these patients. Site‐selective pacing with a smaller diameter lead is achievable with the model 3830 lead (SelectSecure®, Medtronic Inc., Minneapolis, MN, USA), which was specifically designed to target these complications. We describe our initial experience with the Model 3830 lead in patients with CHD.
Methods: Retrospective analysis of all patients undergoing site‐selective implantation of a Model 3830 lead(s) from two congenital heart centers (Bristol, UK, and Dublin, Ireland) from October 2004 until February 2008.
Results: We implanted 139 SelectSecure® leads (atrial n = 70; ventricular n = 69) in 90 patients (57 male) with CHD. Median age at implantation: 13.4 years (1.1–59.2 years), median weight: 43 kg. Sixty‐nine patients (76%) were children (<18 years). Indications for lead implantation included atrioventricular block (n = 55), sinus node disease (n = 18), implantable cardiac defibrillator (n = 12), antitachycardia pacing (n = 4), and cardiac resynchronization (n = 1). Twenty‐two patients underwent pre‐existing lead extraction during the same procedure. All the attempted procedures resulted in successful pacing. One patient had a significantly raised threshold at implantation. There was no procedural mortality. There were two procedural complications. Three patients required lead repositioning for increasing thresholds early postprocedure (<6 weeks). Four leads (2.9%) had displaced on median follow‐up of 21.8 months (0.5–42 months).
Conclusions: The Model 3830 lead is safe and effective in patients with CHD. This is a technically challenging patient group yet procedural complication and lead displacement rates are acceptable.
The decrease in electrically evoked force production is delayed by a previous bout of stretch–shortening cycle exercise
Authors: Kamandulis S. , Skurvydas A. , Masiulis N. , Mamkus G. , Westerblad H. 
Published: September 2009

AbstractAim:  Unaccustomed physical exercise with a large eccentric component is accompanied by muscle damage and impaired contractile function, especially at low stimulation frequencies. A repeated bout of eccentric exercise results in less damage and improved recovery of contractile function. Here we test the hypotheses that (1) a prior stretch–shortening cycle (SSC) exercise protects against impaired muscle function during a subsequent bout of SSC exercise and (2) the protection during exercise is transient and becomes less effective as the exercise progresses.Methods:  Healthy untrained men (n = 7) performed SSC exercise consisting of 100 maximal drop jumps at 30 s intervals. The same exercise was repeated 4 weeks later. Peak quadriceps muscle force evoked by electrical stimulation at 15 (P15) and 50 (P50) Hz was measured before exercise, after 10, 25, 50 and 100 jumps as well as 1 and 24 h after exercise.Results:  P15 and P50 were higher during the initial phase of the repeated bout compared with the first exercise bout, but there was no difference between the bouts at the end of the exercise periods. P15 and P50 were again larger 24 h after the repeated bout. The P15/P50 ratio during exercise was not different between the two bouts, but it was higher after the repeated bout.Conclusion:  A prior bout of SSC exercise temporarily protects against impaired contractile function during a repeated exercise bout. The protection can again be seen after exercise, but the underlying mechanism then seems to be different.
Potassium‐transporting proteins in skeletal muscle: cellular location and fibre‐type differences
Authors: Kristensen M. , Juel C. 
Published: September 2009

AbstractPotassium (K+) displacement in skeletal muscle may be an important factor in the development of muscle fatigue during intense exercise. It has been shownin vitrothat an increase in the extracellular K+concentration ([K+]e) to values higher than approx. 10 mmsignificantly reduce force development in unfatigued skeletal muscle. Severalin vivostudies have shown that [K+]eincreases progressively with increasing work intensity, reaching values higher than 10 mm. This increase in [K+]eis expected to be even higher in the transverse (T)‐tubules than the concentration reached in the interstitium. Besides the voltage‐sensitive K+(Kv) channels that generate the action potential (AP) it is suggested that the big‐conductance Ca2+‐dependent K+(KCa1.1) channel contributes significantly to the K+release into the T‐tubules. Also the ATP‐dependent K+(KATP) channel participates, but is suggested primarily to participate in K+release to the interstitium. Because there is restricted diffusion of K+to the interstitium, K+released to the T‐tubules during AP propagation will be removed primarily by reuptake mediated by transport proteins located in the T‐tubule membrane. The most important protein that mediates K+reuptake in the T‐tubules is the Na+,K+‐ATPase α2dimers, but a significant contribution of the strong inward rectifier K+(Kir2.1) channel is also suggested. The Na+, K+, 2Cl−1 (NKCC1) cotransporter also participates in K+reuptake but probably mainly from the interstitium. The relative content of the different K+‐transporting proteins differs in oxidative and glycolytic muscles, and might explain the different [K+]etolerance observed.
Demons in Ancient Egypt
Authors: Szpakowska Kasia 
Published: September 2009

AbstractWhile much has been written on the topic of deities and the dead in Ancient Egypt, the systematic study of demons has only recently come to the fore of scholarly studies. Preliminary typologies based on surviving spells, prescriptions, and apotropaic devices suggests the theory that these hostile entities were divided into sub‐types in the Egyptian worldview, distinguished from each other by the specific illnesses and conditions they caused, and as well as by the prescribed means of repulsion and protection. Along with hostile demons, a related category of benevolent genii can be discerned. This paper presents an overview of demons and genii in Pharaonic Egypt based primarily on sources from the Middle Kingdom through the New Kingdom.