Worldwide Persistence, Business Cycles, and Economic Growth

We study the time series properties of aggregate data drawn from the Penn World Tables using numerical Bayesian procedures which facilitate inference with small samples. We find substantial persistence in world aggregates, and some evidence for a world business cycle. Across economies, there is great dispersion in our measure of persistence of shocks to real gross domestic product. That we also find no evidence of a relationship between growth and persistence sheds light on which of two competing models of endogenous growth is likely to be able to explain the PWT data

Conforming finite element methods for the clamped plate problem

Finite element methods for solving biharmonic boundary value problems are considered. The particular problem discussed is that of a clamped thin plate. This problem is reformulated in a weak, form in the Sobolev space Techniques for setting up conforming trial Functions are utilized in a Galerkin technique to produce finite element solutions. The shortcomings of various trial function formulations are discussed, and a macro—element approach to local mesh refinement using rectangular elements is given

Leptin-induced endothelium-dependent vasorelaxation of peripheral arteries in lean and obese rats: role of nitric oxide and hydrogen sulfide.

Published onlineJournal ArticleResearch Support, Non-U.S. Gov'tAdipose tissue hormone leptin induces endothelium-dependent vasorelaxation mediated by nitric oxide (NO) and endothelium-derived hyperpolarizing factors (EDHF). Previously it has been demonstrated that in short-term obesity the NO-dependent and the EDHF-dependent components of vascular effect of leptin are impaired and up-regulated, respectively. Herein we examined the mechanism of the EDHF-dependent vasodilatory effect of leptin and tested the hypothesis that alterations of acute vascular effects of leptin in obesity are accounted for by chronic hyperleptinemia. The study was performed in 5 groups of rats: (1) control, (2) treated with exogenous leptin for 1 week to induce hyperleptinemia, (3) obese, fed highly-palatable diet for 4 weeks, (4) obese treated with pegylated superactive rat leptin receptor antagonist (PEG-SRLA) for 1 week, (5) fed standard chow and treated with PEG-SRLA. Acute effect of leptin on isometric tension of mesenteric artery segments was measured ex vivo. Leptin relaxed phenylephrine-preconstricted vascular segments in NO- and EDHF-dependent manner. The NO-dependent component was impaired and the EDHF-dependent component was increased in the leptin-treated and obese groups and in the latter group both these effects were abolished by PEG-SRLA. The EDHF-dependent vasodilatory effect of leptin was blocked by either the inhibitor of cystathionine γ-lyase, propargylglycine, or a hydrogen sulfide (H2S) scavenger, bismuth (III) subsalicylate. The results indicate that NO deficiency is compensated by the up-regulation of EDHF in obese rats and both effects are accounted for by chronic hyperleptinemia. The EDHF-dependent component of leptin-induced vasorelaxation is mediated, at least partially, by H2S.The study was supported by the EU Project “The equipment of innovative laboratories doing research on new medicines used in the therapy of civilization and neoplastic diseases” within the Operational Program Development of Eastern Poland 2007 - 2013, Priority Axis I Modern Economy, Operations I.3 Innovation Promotion. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Identifying key denning habitat to conserve brown bear (Ursus arctos) in Croatia

CONTEXT: The preservation of denning habitat is paramount to the recovery of threatened bear populations because of the effect that den site disturbance can have on cub mortality. Understanding habitat suitability for denning can allow management efforts to be directed towards the regions where conservation interventions would be most effective. AIM: We sought to identify the environmental and anthropogenic habitat variables associated with the presence of Eurasian brown bear (Ursus arctos) den sites in Croatia. Based on these associations, in order to inform future conservation decisions, we also sought to identify regions of high suitability for denning across Croatia. METHODS: Using the locations of 91 dens inhabited by bears between 1982 and 2011, we opted for the presence-only modelling option in software Maxent to determine the most important predictors of den presence, and thus predict the distribution of high-value denning habitat across Croatia. KEY RESULTS: We found that structural elements were the most important predictors, with ruggedness and elevation both relating positively to den presence. However, distance to nearest settlement was also positively associated with den presence. CONCLUSION: We determine that there is considerable denning habitat value in areas with high and rugged terrain as well as areas with limited human activity. We suspect that high and rugged terrain contains a greater concentration of the karstic formations used for denning than lower-lying regions. IMPLICATIONS: Our study presents the first habitat suitability model for brown bears in Croatia, and identifies core areas suitable for denning both within and outside the species’ current range. As such, it provides useful evidence for conservation decision making and the development of scientifically-based management plans. Our results also support the need for finer spatial scale studies that can reveal specific denning preferences of subpopulations

STROZ Lidar Results at the MOHAVE III Campaign, October, 2009, Table Mountain, CA

During October, 2009 the GSFC STROZ Lidar participated in a campaign at the JPL Table Mountain Facility (Wrightwood, CA, 2285 m Elevation) to measure vertical profiles of water vapor from near the ground to the lower stratosphere. On eleven nights, water vapor, aerosol, temperature and ozone profiles were measured by the STROZ lidar, two other similar lidars, frost-point hygrometer sondes, and ground-based microwave instruments made measurements. Results from these measurements and an evaluation of the performance of the STROZ lidar during the campaign will be presented in this paper. The STROZ lidar was able to measure water vapor up to 13-14 km ASL during the campaign. We will present results from all the STROZ data products and comparisons with other instruments made. Implications for instrumental changes will be discussed

Pharmacological postconditioning against myocardial infarction with a slow-releasing hydrogen sulfide donor, GYY4137

Exogenous hydrogen sulfide (H2S) protects against myocardial ischemia/reperfusion injury but the mechanism of action is unclear. The present study investigated the effect of GYY4137, a slow-releasing H2S donor, on myocardial infarction given specifically at reperfusion and the signalling pathway involved. Thiobutabarbital-anesthetised rats were subjected to 30min of left coronary artery occlusion and 2h reperfusion. Infarct size was assessed by tetrazolium staining. In the first study, animals randomly received either no treatment or GYY4137 (26.6, 133 or 266μmolkg-1) by intravenous injection 10min before reperfusion. In a second series, involvement of PI3K and NO signalling were interrogated by concomitant administration of LY294002 or L-NAME respectively and the effects on the phosphorylation of Akt, eNOS, GSK-3β and ERK1/2 during early reperfusion were assessed by immunoblotting. GYY4137 266μmolkg-1 significantly limited infarct size by 47% compared to control hearts (P<0.01). In GYY4137-treated hearts, phosphorylation of Akt, eNOS and GSK-3β was increased 2.8, 2.2 and 2.2 fold respectively at early reperfusion. Co-administration of L-NAME and GYY4137 attenuated the cardioprotection afforded by GYY4137, associated with attenuated phosphorylation of eNOS. LY294002 totally abrogated the infarct-limiting effect of GYY4137 and inhibited Akt, eNOS and GSK-3β phosphorylation. These data are the first to demonstrate that GYY4137 protects the heart against lethal reperfusion injury through activation of PI3K/Akt signalling, with partial dependency on NO signalling and inhibition of GSK-3β during early reperfusion. H2S-based therapeutic approaches may have value as adjuncts to reperfusion in the treatment of acute myocardial infarction

Allocating the Burdens of Climate Action: Consumption-Based Carbon Accounting and the Polluter-Pays Principle

Action must be taken to combat climate change. Yet, how the costs of climate action should be allocated among states remains a question. One popular answer—the polluter-pays principle (PPP)—stipulates that those responsible for causing the problem should pay to address it. While intuitively plausible, the PPP has been subjected to withering criticism in recent years. It is timely, following the Paris Agreement, to develop a new version: one that does not focus on historical production-based emissions but rather allocates climate burdens in proportion to each state’s annual consumption-based emissions. This change in carbon accounting results in a fairer and more environmentally effective principle for distributing climate duties

Quantum graphs where back-scattering is prohibited

We describe a new class of scattering matrices for quantum graphs in which back-scattering is prohibited. We discuss some properties of quantum graphs with these scattering matrices and explain the advantages and interest in their study. We also provide two methods to build the vertex scattering matrices needed for their construction.Comment: 15 page

Ap39, a mitochondria-targeting hydrogen sulfide (H2 s) donor, protects against myocardial reperfusion injury independently of salvage kinase signalling

Background and Purpose H2S protects myocardium against ischaemia-reperfusion injury. This protection may involve the cytosolic reperfusion injury salvage kinase (RISK) pathway, but direct effects on mitochondrial function are possible. Here, we investigated the potential cardioprotective effect of mitochondria-specific H2S donor, AP39, at reperfusion against ischaemia/reperfusion injury. Experimental Approach Anaesthetised rats underwent myocardial (30 min ischaemia/120 min reperfusion) with randomisation to receive interventions prior to reperfusion: vehicle, AP39 (0.01, 0.1, 1 µmol kg-1), or the control compounds AP219 or ADT-OH (1 µmol kg-1). LY294002, L-NAME or ODQ were used to interrogate the involvement of RISK pathway. Myocardial samples harvested 5 minutes after reperfusion were analysed for RISK protein phosphorylation and additional experiments were conducted on isolated cardiac mitochondria to examine the direct mitochondrial effects of AP39. Key Results AP39 exerted dose-dependent infarct size limitation. Inhibition of either PI3K/Akt, eNOS or sGC did not affect the infarct limitation of AP39. Western blot analysis confirmed that AP39 did not induce phosphorylation of Akt, eNOS, GSK-3β or ERK1/2. In isolated subsarcolemmal and interfibrillar mitochondria, AP39 significantly attenuated mitochondrial ROS generation without affecting respiratory complexes I or II. Further, AP39 inhibited mitochondrial permeability transition pore (PTP) opening and co-incubation of mitochondria with AP39 and cyclosporine A induced an additive inhibition of PTP. Conclusion and Implications AP39 protects against reperfusion injury independently of the cytosolic RISK pathway. Cardioprotection could be mediated by inhibiting PTP via cyclophilin D-independent mechanism. Thus, selective delivery of H2S to mitochondria may be therapeutically applicable for harnessing the cardioprotective utility of H2S. This article is protected by copyright. All rights reserved

Fiddling while the ice melts? How organizational scholars can take a more active role in the climate change debate

The debate over anthropogenic climate change or the idea that human activities are altering the physical climate of the planet continues to rage amid seemingly irreconcilable differences, both within the developed world and between developed and less developed countries. With high uncertainty, rival worldviews, and wide diversity of meaning attached to the expression, climate change has become a key narrative within which local and transnational issues – economic, social, and political – are framed and contested. The field is fraught with controversies regarding causes and consequences, as well as different attitudes toward risks, technologies, and economic and social well-being for different groups. Parties also dispute how to share responsibility for reducing emissions – whether the issue primarily needs market, regulatory, technological, or behavioral solutions. Climate change is many things to many people. Competing interests negotiate over its interpretation and utilize various strategies to promote practices that advance their own understandings regarding climate change and its governance