186 research outputs found
Anomalies in a waterlike model confined between plates
Using molecular dynamic simulations we study a waterlike model confined
between two fixed hydrophobic plates. The system is tested for density,
diffusion and structural anomalous behavior and compared with the bulk results.
Within the range of confining distances we had explored we observe that in the
pressure-temperature phase diagram the temperature of maximum density (TMD
line), the temperature of maximum and minimum diffusion occur at lower
temperatures when compared with the bulk values. For distances between the two
layers below a certain threshold ,, only two layers of particles are
formed, for three or more layers are formed. In the case of three
layers the central layer stays liquid while the contact layers crystallize.
This result is in agreement with simulations for atomistic models
Decentralization Policy and The Struggle for Authority Over Forest Resources in Tebo Regency, Jambi
Kebijakan desentralisasi atau yang umum dikenal dengan istilah otonomi daerah mengamanatkan kepada pusat untuk menyerahkan berbagai kewenangan pemerintahan kepadadaerah. Penyerahan kewenangan kepada daerah ini dimaksudkan agar tata pemerintahan dan pelayanan publik dapat berjalan secara lebih efektif dan efisien. Namun, peralihan sistem pemerintahan dari sentralisasi ke desentralisasi tidak selamanya berjalan lurus mulus. Ketegangan hubungan pusat dan daerah terjadi akibat keengganan penyelenggara pemerintahan di tingkat pusatmenyerahkan kewenangan kepada daerah dan egoisme kedaerahan yang berlebihan ditandai dengan terbitnya berbagai Peraturan Daerah yang bertentangan dengan peraturan di atasnya. Hal ini mengakibatkan ketidakpastian hukum yang berpotensi memicu konflik antara pusat dan daerah serta antara kelompok masyarakat menyangkut hak mereka untuk mendapatkan manfaat, akses dan tanggung jawab atas sumber daya alam termasuk huta
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Mental contrasting spurs energy by changing implicit evaluations of obstacles
Mentally contrasting a desired future with the obstacle of current reality produces expectancy-dependent changes in explicit evaluations of the obstacle of current reality. Past research has shown that these changes at least partly mediate the beneficial effects of mental contrasting on performance. We tested whether mental contrasting also leads to expectancy-dependent changes in implicit evaluations of the obstacle and whether those changes mediate mental contrasting effects on energization and performance. In 3 studies, participants named a desired future (improving interpersonal relationships, Study 1; excelling in a creativity test, Study 2; and improving one’s eating habits, Study 3) and named an important obstacle standing in the way of attaining the desired future. They then engaged in either mental contrasting or control exercises. We assessed participants’ implicit evaluations of their obstacles. Participants in the mental contrasting (vs. control) conditions implicitly evaluated their obstacles more negatively when they had high expectations of success (Studies 1, 2, and 3). Furthermore, expectancy-dependent changes in implicit evaluations of obstacles (i.e., food temptations) mediated mental contrasting effects on energization, which, in turn, predicted commitment and performance (i.e., commitment to eat healthily and healthy eating over the course of 2 weeks, Study 3)
Decentralization Policy and The Struggle for Authority Over Forest Resources in Tebo Regency, Jambi
Kebijakan desentralisasi atau yang umum dikenal dengan istilah otonomi daerah mengamanatkan kepada pusat untuk menyerahkan berbagai kewenangan pemerintahan kepadadaerah. Penyerahan kewenangan kepada daerah ini dimaksudkan agar tata pemerintahan dan pelayanan publik dapat berjalan secara lebih efektif dan efisien. Namun, peralihan sistem pemerintahan dari sentralisasi ke desentralisasi tidak selamanya berjalan lurus mulus. Ketegangan hubungan pusat dan daerah terjadi akibat keengganan penyelenggara pemerintahan di tingkat pusatmenyerahkan kewenangan kepada daerah dan egoisme kedaerahan yang berlebihan ditandai dengan terbitnya berbagai Peraturan Daerah yang bertentangan dengan peraturan di atasnya. Hal ini mengakibatkan ketidakpastian hukum yang berpotensi memicu konflik antara pusat dan daerah serta antara kelompok masyarakat menyangkut hak mereka untuk mendapatkan manfaat, akses dan tanggung jawab atas sumber daya alam termasuk huta
On the chemical biology of the nitrite/sulfide interaction
Sulfide (H2S/HS(-)) has been demonstrated to exert an astounding breadth of biological effects, some of which resemble those of nitric oxide (NO). While the chemistry, biochemistry and potential (patho)physiology of the cross-talk between sulfide and NO has received considerable attention lately, a comparable assessment of the potential biological implications of an interaction between nitrite and sulfide is lacking. This is surprising inasmuch as nitrite is not only a known bioactive oxidation product of NO, but also efficiently converted to S-nitrosothiols in vivo; the latter have been shown to rapidly react with sulfide in vitro, leading to formation of S/N-hybrid species including thionitrite (SNO(-)) and nitrosopersulfide (SSNO(-)). Moreover, nitrite is used as a potent remedy against sulfide poisoning in the clinic. The chemistry of interaction between nitrite and sulfide or related bioactive metabolites including polysulfides and elemental sulfur has been extensively studied in the past, yet much of this information appears to have been forgotten. In this review, we focus on the potential chemical biology of the interaction between nitrite and sulfide or sulfane sulfur molecules, calling attention to the fundamental chemical properties and reactivity of either species and discuss its possible contribution to the biology, pharmacology and toxicology of both nitrite and sulfide
Red Blood Cell and Endothelial eNOS Independently Regulate Circulating Nitric Oxide Metabolites and Blood Pressure
Background: Current paradigms suggest that nitric oxide (NO) produced by endothelial cells (ECs) through endothelial nitric oxide synthase (eNOS) in the vessel wall is the primary regulator of blood flow and blood pressure. However, red blood cells (RBCs) also carry a catalytically active eNOS, but its role is controversial and remains undefined. This study aimed to elucidate the functional significance of RBC eNOS compared with EC eNOS for vascular hemodynamics and nitric oxide metabolism. Methods: We generated tissue-specific loss- and gain-of-function models for eNOS by using cell-specific Cre-induced gene inactivation or reactivation. We created 2 founder lines carrying a floxed eNOS (eNOSflox/flox) for Cre-inducible knockout (KO), and gene construct with an inactivated floxed/inverted exon (eNOSinv/inv) for a Cre-inducible knock-in (KI), which respectively allow targeted deletion or reactivation of eNOS in erythroid cells (RBC eNOS KO or RBC eNOS KI mice) or in ECs (EC eNOS KO or EC eNOS KI mice). Vascular function, hemodynamics, and nitric oxide metabolism were compared ex vivo and in vivo. Results: The EC eNOS KOs exhibited significantly impaired aortic dilatory responses to acetylcholine, loss of flow-mediated dilation, and increased systolic and diastolic blood pressure. RBC eNOS KO mice showed no alterations in acetylcholine-mediated dilation or flow-mediated dilation but were hypertensive. Treatment with the nitric oxide synthase inhibitor NÎł-nitro-l-arginine methyl ester further increased blood pressure in RBC eNOS KOs, demonstrating that eNOS in both ECs and RBCs contributes to blood pressure regulation. Although both EC eNOS KOs and RBC eNOS KOs had lower plasma nitrite and nitrate concentrations, the levels of bound NO in RBCs were lower in RBC eNOS KOs than in EC eNOS KOs. Reactivation of eNOS in ECs or RBCs rescues the hypertensive phenotype of the eNOSinv/invmice, whereas the levels of bound NO were restored only in RBC eNOS KI mice. Conclusions: These data reveal that eNOS in ECs and RBCs contribute independently to blood pressure homeostasis
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The reactive species interactome: evolutionary emergence, biological significance, and opportunities for redox metabolomics and personalized medicine
SIGNIFICANCE: Oxidative stress is thought to account for aberrant redox homeostasis and contribute to aging and disease. However, more often than not administration of antioxidants is ineffective, suggesting our current understanding of the underlying regulatory processes is incomplete. Recent Advances. Similar to reactive oxygen and nitrogen species (ROS, RNS), reactive sulfur species (RSS) are now emerging as important signaling molecules, targeting regulatory cysteine redox switches in proteins, affecting gene regulation, ion transport, intermediary metabolism and mitochondrial function. To rationalize the complexity of chemical interactions of reactive species with themselves and their targets and help define their role in systemic metabolic control, we here introduce a novel integrative concept coined the reactive species interactome (RSI). The RSI is a primeval multi-level redox-regulatory system whose architecture, together with the physicochemical characteristics of its constituents, allows efficient sensing and rapid adaptation to environmental changes and various other stresses to enhance fitness and resilience at the local and whole-organism level.
CRITICAL ISSUES: To better characterise the RSI-related processes that determine fluxes through specific pathways and enable integration, it is necessary to disentangle the chemical biology and activity of reactive species (including precursors and reaction products), their targets, communication systems and effects on cellular, organ and whole-organism bioenergetics using systems-level/network analyses.
FUTURE DIRECTIONS: Understanding the mechanisms through which the RSI operates will enable a better appreciation of the possibilities to modulate the entire biological system; moreover, unveiling molecular signatures that characterize specific environmental challenges or other stresses will provide new prevention/intervention opportunities for personalized medicine
REDD+ policy design and policy learning:The emergence of an integrated landscape approach in Vietnam
Discourses of conflict and collaboration and institutional context in the implementation of forest conservation policies in Soria, Spain
This article examines the emergence of conflict and collaboration in the implementation of forest conservation policies in Soria, Spain. We draw insights from discursive institutionalism and use a comparative case study approach to analyse and compare a situation of social conflict over the Natural Park declaration in the Sierra de Urbión, and a civil society led collaborative process to develop management plans for the “Sierra de Cabrejas” in Soria. The implementation of the EU Habitats Directive generated different outcomes in these two cases, which unfolded in the context of the same nature conservation legislation and national and provincial administrative structures but differed in terms of types of forests involved, property rights arrangements and forest use histories. We critically examine the influence of the institutional context and dominant discourses on the emergence of outcomes: conflict emerged where local institutions and discourses were threatened by the EU directive, while collaboration was possible where local institutions and counter-discourses were weak. We find that the institutional context plays an important part in determining local discourses in the implementation of forest conservation policies. Yet local counter-discourses have limited influence in the implementation and policy processes in the face of contestation by the discourses of regional civil servants conservation activists
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