bluuebunny/crossref_metadata_2025_split huggingface dataset:
Executives—The American Presidency
Authors: Howell William G. 
Published: September 2009

Abstract
This article provides a survey of the state of quantitative research on the presidency twenty-five years after Edwards issued his original entreaty. It briefly documents the publication trends on quantitative research on the presidency that has been found by a variety of professionals. This is followed by a review of the contributions of selected quantitative studies to long-standing debates about the centralization of presidential policy-making, presidential authority, and public appeals. This article focuses on the ways recent scholarship addresses methodological issues that regularly affect studies of the organization of political institutions, their interactions with the public, and their influence in systems of separated powers.
Executives In Parliamentary Government
Authors: Rhodes R. A. W. 
Published: September 2009

Abstract
This article examines the executives in parliamentary government, starting with existing approaches to executive government. These include modernist-empiricism, Westminster, rational choice institutionalism, and core executive. The next section looks at the core debates and challenges in the study of parliamentary executives, such as the Commonwealth, Britain, and Western Europe. The next sections cover their executive coordination, the presidentialization of prime ministers, policy capacity, comparative analysis of parliamentary government, and policy advice.
Electoral Systems
Authors: Bowler Shaun 
Published: September 2009

Abstract
This article views electoral systems and electoral system change from an institutional perspective. This perspective lends itself to a rational actor framework that highlights the strategic choices made by voters and political elites. This article has a central organizing theme, which is the way Duverger's Law can be taken to be the canonical statement of what electoral systems (as institutions) do and why the choice of electoral institutions is important. It discusses the changes in electoral systems and even the remarkable lack of change in electoral systems worldwide.
International Economic Institutions
Authors: Martin Lisa L. 
Published: September 2009

Abstract
This article focuses on international economic institutions, particularly on institutions that structure trade and financial relationships. It considers the General Agreement on Tariffs and Trade (GATT) and the World Trade Organization (WTO), regional trade organizations, and the Bretton Woods institutions. The article provides some background information on the study of institutions, generally in international relations. It also focuses on trade organizations and international financial institutions.
About Institutions, Mainly, but not Exclusively, Political
Authors: Blondel Jean 
Published: September 2009

Abstract
This article discusses the concept of institution by examining the components of an institution and the way in which institutionalization can increase or decrease. It considers the place to be given to organizations and to procedures based on the definition of institutions. It reveals the major differences across the social sciences and in particular political, social, and economic fields. The article is also concerned with institutionalization, and reveals marked differences among the social sciences.
Political Institutions—Old and New
Authors: von Beyme Klaus 
Published: September 2009

Abstract
This article discusses the old and new political institutions. It begins with a study of the transformation from old institutions to new institutions; it is noted that there are a few ‘new institutions’ that developed in the three waves of democratization. The article also examines the evolution of the theories of institutions. The discussion shows that institutions develop less quickly than theories on institutions. ‘Historical institutions’ even demonstrate that institutional traditions are not easy to change.
Trade, Immigration, and Cross‐Border Investment
Authors: Rogowski Ronald 
Published: September 2009

AbstractThis article discusses the implications of four models related to trade, immigration, and cross-border investment. These four models are: Hecksher-Ohlin, Samuelson-Jones and Ricardo-Viner, neo-Ricardian, and Economies of Scale. The first three models assume constant returns to scale, but all models make the conventional assumption of diminishing marginal returns to any individual factor. The article discusses each model in detail, focusing on trade in products and cross-border migration and investment.
Economic Methods in Positive Political Theory
Authors: Austen-Smith David 
Published: September 2009

Abstract
This article focuses on economic methods in political science, specifically on positive political theory. It provides a sketch of the two canonical approaches to developing a positive political theory: collective preference theory and game theory. It is argued that these two techniques are distinguished by their trade-offs, despite having some clear formal differences. The article also considers other specific techniques within the game-theoretic approach, which are designed to accommodate two important analytical characteristics that are distinctive to political science.
What is Missing from Political Economy
Authors: North Douglass C. 
Published: September 2009

Abstract
This article discusses what is missing from the literature on political economy. The first section discusses the need for a dynamic theory, which is illustrated in three examples provided in the latter portion of the article. It then examines the centrality of beliefs and argues that the failure to understand some fundamental questions reflects that social science fails to have a truly dynamic theory that considers the non-ergodic nature of the world.
Modeling Party Competition in General Elections
Authors: Roemer John E. 
Published: September 2009

Abstract
This article provides a report on the attempts to reproduce political equilibrium among parties and its applications. It examines a review of the two main theories of political competition, and notes the problems that are involved in generalizing these theories to the multidimensional context. It also proposes a resolution to these problems, specifically a theory of multidimensional political competition. The article ends with a discussion of some applications of this theory.
Legal Perspectives
Authors: Alvarez José E. 
Published: September 2009

Abstract
This article provides a summary of the author's writing and teaching at several well-known law schools. The article addresses how the international organizations with a global reach have changed the mechanisms and reasoning behind the making, implementation, and enforcement of international law. It also notes the disappearance of a rather religious faith in law and multilateral approaches that had become characteristic of the legal culture among those who helped design the world organization in the 1940s.
Bretton Woods Institutions
Authors: Woods Ngaire 
Published: September 2009

Abstract
This article discusses the Bretton Woods Institutions, which are often described as the ‘sister institutions’ of the United Nations. It explains how the World Bank and the International Monetary Fund (IMF) generated heated debate and criticism, most especially over the past twenty years. It shows what the institutions do and determines why they have become controversial. The article also identifies the two key factors that limit the effectiveness of the institutions.
Uncalibrated Stroke Volume Variations Are Able to Predict the Hemodynamic Effects of Positive End-Expiratory Pressure in Patients with Acute Lung Injury or Acute Respiratory Distress Syndrome after Liver Transplantation
Authors: Biais Matthieu , Nouette-Gaulain Karine , Quinart Alice , Roullet Stéphanie , Revel Philippe , Sztark François 
Published: September 2009

Background
Positive end-expiratory pressure (PEEP) may reduce cardiac output and total hepatic blood flow after liver transplantation. Pulse pressure variation is useful in predicting the PEEP-induced decrease in cardiac output. The aim of the study was to examine the relationships between stroke volume variations (SVV) obtained with the Vigileo monitor (Edwards Lifesciences, Irvine, CA), and the hemodynamic effects of PEEP.

Methods
Over 2 yr, patients presenting an acute lung injury or an acute respiratory distress syndrome in the 72 h after liver transplantation were prospectively enrolled. Patients were monitored with a pulmonary artery catheter (stroke volume) and with the Vigileo system (stroke volume and SVV). Measurements were performed in duplicate, first during zero end-expiratory pressure and then 10 min after the addition of 10 cm H2O PEEP.

Results
Twenty-six patients were included. Six patients were excluded from analysis. On PEEP, SVV and pulse pressure variation increased significantly and stroke volume decreased significantly. PEEP-induced changes in stroke volume measured by pulmonary artery catheter were significantly correlated with SVV (r = 0.69; P < 0.001) and pulse pressure variation on zero end-expiratory pressure (r = 0.66, P < 0.001). PEEP-induced decrease in stroke volume measured by pulmonary artery catheter > or = 15% was predicted by an SVV > 7% (sensitivity = 100%, specificity = 80%) and by a pulse pressure variation > 8% (sensitivity = 80%, specificity = 100%). PEEP-induced changes in stroke volume measured by pulmonary artery catheter and Vigileo device were correlated (r = 0.51, P < 0.005).

Conclusions
SVV obtained with Vigileo monitor is useful to predict decrease in stroke volume induced by PEEP. Moreover, this device is able to track changes in stroke volume induced by PEEP.
Nitrous Oxide Plus Isoflurane Induces Apoptosis and Increases β-Amyloid Protein Levels
Authors: Zhen Yu , Dong Yuanlin , Wu Xu , Xu Zhipeng , Lu Yan , Zhang Yiying , Norton David , Tian Ming , Li Shuren , Xie Zhongcong 
Published: September 2009

Background
Some anesthetics have been suggested to induce neurotoxicity, including promotion of Alzheimer's disease neuropathogenesis. Nitrous oxide and isoflurane are common anesthetics. The authors set out to assess the effects of nitrous oxide and/or isoflurane on apoptosis and beta-amyloid (Abeta) levels in H4 human neuroglioma cells and primary neurons from naïve mice.

Methods
The cells or neurons were exposed to 70% nitrous oxide and/or 1% isoflurane for 6 h. The cells or neurons and conditioned media were harvested at the end of the treatment. Caspase-3 activation, apoptosis, processing of amyloid precursor protein, and Abeta levels were determined.

Results
Treatment with a combination of 70% nitrous oxide and 1% isoflurane for 6 h induced caspase-3 activation and apoptosis in H4 naïve cells and primary neurons from naïve mice. The 70% nitrous oxide plus 1% isoflurane, but neither alone, for 6 h induced caspase-3 activation and apoptosis, and increased levels of beta-site amyloid precursor protein-cleaving enzyme and Abeta in H4-amyloid precursor protein cells. In addition, the nitrous oxide plus isoflurane-induced Abeta generation was reduced by a broad caspase inhibitor, Z-VAD. Finally, the nitrous oxide plus isoflurane-induced caspase-3 activation was attenuated by gamma-secretase inhibitor L-685,458, but potentiated by exogenously added Abeta.

Conclusion
These results suggest that the common anesthetics nitrous oxide plus isoflurane may promote neurotoxicity by inducing apoptosis and increasing Abeta levels. The generated Abeta may further potentiate apoptosis to form another round of apoptosis and Abeta generation. More studies, especially the in vivo confirmation of these in vitro findings, are needed.
S(+)-ketamine Effect on Experimental Pain and Cardiac Output
Authors: Sigtermans Marnix , Dahan Albert , Mooren René , Bauer Martin , Kest Benjamin , Sarton Elise , Olofsen Erik 
Published: September 2009

Background
Low-dose ketamine behaves as an analgesic in the treatment of acute and chronic pain. To further understand ketamine's therapeutic profile, the authors performed a population pharmacokinetic-pharmacodynamic analysis of the S(+)-ketamine analgesic and nonanalgesic effects in healthy volunteers.

Methods
Ten men and ten women received a 2-h S(+)-ketamine infusion. The infusion was increased at 40 ng/ml per 15 min to reach a maximum of 320 ng/ml. The following measurements were made: arterial plasma S(+)-ketamine and S(+)-norketamine concentrations, heat pain intensity, electrical pain tolerance, drug high, and cardiac output. The data were modeled by using sigmoid Emax models of S(+)-ketamine concentration versus effect and S(+)-ketamine + S(+)-norketamine concentrations versus effect.

Results
Sex differences observed were restricted to pharmacokinetic model parameters, with a 20% greater elimination clearance of S(+)-ketamine and S(+)-norketamine in women resulting in higher drug plasma concentrations in men. S(+)-ketamine produced profound drug high and analgesia with six times greater potency in the heat pain than the electrical pain test. After ketamine-infusion, analgesia rapidly dissipated; in the heat pain test but not the electrical pain test, analgesia was followed by a period of hyperalgesia. Over the dose range tested, ketamine produced a 40-50% increase in cardiac output. A significant consistent contribution of S(+)-norketamine to overall effect was detected for none of the outcome parameters.

Conclusions
S(+)-ketamine displays clinically relevant sex differences in its pharmacokinetics. It is a potent analgesic at already low plasma concentrations, but it is associated with intense side effects.
Hemodynamic Effects of Ephedrine, Phenylephrine, and the Coadministration of Phenylephrine with Oxytocin during Spinal Anesthesia for Elective Cesarean Delivery
Authors: Dyer Robert A. , Reed Anthony R. , van Dyk Dominique , Arcache Michelle J. , Hodges Owen , Lombard Carl J. , Greenwood Jaime , James Michael F. 
Published: September 2009

Background
Hemodynamic responses to vasopressors used during spinal anesthesia for elective Cesarean delivery, have not been well described. This study compared the effects of bolus phenylephrine and ephedrine on maternal cardiac output (CO). The hypothesis was that phenylephrine, but not ephedrine, decreases CO when administered in response to hypotension during spinal anesthesia.

Methods
Forty-three patients were randomized to receive 80 microg of phenylephrine or 10 mg of ephedrine. Both pulse wave form analysis and transthoracic bioimpedance changes were used to estimate stroke volume in each patient. Hemodynamic responses to spinal anesthesia and oxytocin were also recorded. A subgroup of 20 patients was randomized to receive oxytocin compared with oxytocin plus 80 microg of phenylephrine after delivery.

Results
Mean CO and maximum absolute response in CO were significantly lower during the 150 s after phenylephrine administration than after ephedrine (6.2 vs. 8.1 l/min, P = 0.001, and 5.2 vs. 9.0 l/min, P < 0.0001, respectively for pulse wave form analysis, and 5.2 vs. 6.3 l/min, P = 0.01 and 4.5 vs. 6.7 l/min, P = 0.0001, respectively for bioimpedance changes). CO changes correlated with heart rate changes. Coadministration of phenylephrine obtunded oxytocin-induced decreases in systemic vascular resistance and increases in heart rate and CO. Trends in CO change were similar using either monitor.

Conclusions
Bolus phenylephrine reduced maternal CO, and decreased CO when compared with ephedrine during elective spinal anesthesia for Cesarean delivery. CO changes correlated with heart rate changes after vasopressor administration, emphasizing the importance of heart rate as a surrogate indicator of CO. Coadministered phenylephrine obtunded hemodynamic responses to oxytocin.
Amnestic Concentrations of Etomidate Modulate GABAA,slowSynaptic Inhibition in Hippocampus
Authors: Dai Shuiping , Perouansky Misha , Pearce Robert A. 
Published: September 2009

Background
Gamma-aminobutyric acid type A (GABA(A)) receptor-mediated inhibition in the central nervous system exists in two forms: phasic (inhibitory postsynaptic currents, IPSCs) and tonic (nonsynaptic). Phasic inhibition is further subdivided into fast (GABA(A,fast)) and slow (GABA(A,slow)) IPSCs. By virtue of its dendritic location and kinetics, GABA(A,slow) has been proposed to control synaptic plasticity and memory. Etomidate is a nonbarbiturate, intravenous anesthetic that selectively modulates GABA(A) receptors and produces amnesia at low doses in vivo. This study tested whether correspondingly low concentrations of etomidate in vitro alter GABA(A,fast) and GABA(A,slow) phasic inhibition.

Methods
Electrophysiological recordings were obtained from hippocampal slices prepared from postnatal day 3-8 mice and maintained in organotypic culture for 10-14 days. Etomidate was applied at concentrations corresponding to one-half to four times the half maximal effective concentration that impairs hippocampus-dependent learning and memory--i.e., 0.125-1.0 microm.

Results
Etomidate 0.25 microm (the half maximal effective concentration) doubled the time constant of decay of GABA(A,slow) IPSCs, but it had no detectable effect on GABA(A,fast) IPSCs. Higher concentrations of etomidate had stronger effects on both types of phasic inhibition: 0.5 and 1 microm etomidate prolonged the time constant of decay by 310% and 410% for GABA(A,slow) and by 25% and 78% for GABA(A,fast). Concentrations of etomidate up to 1 microm had no significant effects on the amplitudes of either GABA(A,fast) or GABA(A,slow) IPSCs.

Conclusions
At concentrations that impair hippocampus-dependent memory, etomidate modulates GABA(A,slow) more strongly than GABA(A,fast) IPSCs. Effects of etomidate on GABA(A,slow) IPSCs may contribute to etomidate-induced amnesia.
Epidural Analgesia in the Latent Phase of Labor and the Risk of Cesarean Delivery
Authors: Wang FuZhou , Shen XiaoFeng , Guo XiRong , Peng YuZhu , Gu XiaoQi 
Published: September 2009

Background
The optimal timing of epidural analgesia has been a controversial issue, and how early women can benefit from epidural analgesia is still debated. The objective of this trial was to test the hypothesis that patient-controlled epidural analgesia given at cervical dilation of 1.0 cm or more does not increase the risk of prolonged labor or Cesarean delivery.

Methods
After institutional review board approval and patient consent, 12,793 nulliparous patients requesting neuraxial analgesia were enrolled and randomized to an early epidural (cervical dilation at least 1.0 cm) or delayed epidural (cervical dilation at least 4.0 cm) group. A 15-ml epidural analgesic mixture consisting of 0.125% (1.25 mg/ml) ropivacaine plus 0.3 microg/ml sufentanil was given in a single bolus, followed by patient-controlled pump with a 10-ml bolus without background infusion. Repeatable meperidine (25 mg) was prescribed as being the rescue analgesic to patients in the delayed epidural group. The primary outcome was the rate of Cesarean section.

Results
The median diameters of cervical dilation were 1.6 cm and 5.1 cm in the early and delayed epidural groups, respectively (P < 0.0001). The duration of labor from analgesia request to vaginal delivery was equal in both groups (11.3 +/- 4.5 h for early epidural and 11.8 +/- 4.9 h for delayed epidural group women, P = 0.90). No statistically significant difference in the rate of Cesarean section was observed between the two groups on the intention-to-treat analysis (23.2% vs. 22.8% in the early and delayed epidural groups, respectively; P = 0.51).

Conclusions
Epidural analgesia in the latent phase of labor at cervical dilation of 1.0 cm or more does not prolong the progression of labor and does not increase the rate of Cesarean in nulliparous women compared with the delayed analgesia at the cervical dilation of 4.0 cm or more.
γ-Amino Butyric Acid Type A Receptor Mutations at β2N265 Alter Etomidate Efficacy While Preserving Basal and Agonist-dependent Activity
Authors: Desai Rooma , Ruesch Dirk , Forman Stuart A. 
Published: September 2009

Background
Etomidate acts at gamma-Aminobutyric acid type A (GABAA) receptors containing beta2 or beta3, but not beta1 subunits. Mutations at beta residue 265 (Ser in beta1; Asn in beta2 or beta3) profoundly affect etomidate sensitivity. Whether these mutations alter etomidate binding remains uncertain.

Methods
Heterologously expressed alpha1beta2gamma2L GABAA receptors and receptors with beta2(N265S) or beta2(N265M) mutations were studied electrophysiologically in both Xenopus oocytes and HEK293 cells. Experiments quantified the impact of beta2N265 mutations or substituting beta1 for beta2 on basal channel activation, GABA EC50, maximal GABA efficacy, etomidate-induced leftward shift in GABA responses, etomidate direct activation, and rapid macrocurrent kinetics. Results were analyzed in the context of an established allosteric co-agonist mechanism.

Results
Mutations produced only small changes in basal channel activity, GABA EC50, maximal GABA efficacy, and macrocurrent kinetics. Relative to wild-type, beta2(N265S) reduced etomidate enhancement of apparent GABA affinity six-fold, and it reduced etomidate direct activation efficacy 14-fold. beta2(N265M) totally eliminated both etomidate modulation of GABA responses and direct channel activation. Mechanism-based analysis showed that the function of both mutants remains consistent with the allosteric co-agonist model and that beta2(N265S) reduced etomidate allosteric efficacy five-fold, whereas etomidate-binding affinity dropped threefold. Experiments swapping beta2 subunits for beta1 indicated that etomidate efficacy is reduced 34-fold, whereas binding affinity drops less than two-fold.

Conclusions
Mutations at beta2N265 profoundly alter etomidate sensitivity with only small changes in basal and GABA-dependent channel activity. Mutations at the beta2N265 residue or replacement of beta2 with beta1 influence etomidate efficacy much more than binding to inactive receptors.