56 research outputs found
Electrochemical Estimations of the Gold Nanoparticle Size Effect on Cysteine-Gold Oxidation,
Gold nanoparticles are interesting for nanobiomedical applications, such as for drug delivery and as diagnostic imaging contrast agents. However, their stability and reactivity in-vivo are influenced by their surface properties and size. Here, we investigate the electrochemical oxidation of differently sized citrate-coated gold nanoparticles in the presence and absence of L-cysteine, a thiol-containing amino acid with high binding affinity to gold. We found that smaller sized (5, 10 nm) gold nanoparticles were significantly more susceptible to electrochemical L-cysteine interactions and/or L-cysteine-facilitated gold oxidation than larger (20, 50 nm) sized gold nanoparticles, both for the same mass and nominal surface area, under the conditions investigated (pH 7.4, room temperature, stagnant solutions, and scan rates of 0.5 to 450 mV s−1). The electrochemical measurements of drop-casted gold nanoparticle suspensions on paraffin-impregnated graphite electrodes were susceptible to the quality of the electrode. Increased cycling resulted in irreversible oxidation and detachment/oxidation of gold into solution. Our results suggest that L-cysteine-gold interactions are stronger for smaller nanoparticles
Contribution of Major Lifestyle Risk Factors for Incident Heart Failure in Older Adults: The Cardiovascular Health Study.
OBJECTIVES: The goal of this study was to determine the relative contribution of major lifestyle factors on the development of heart failure (HF) in older adults. BACKGROUND: HF incurs high morbidity, mortality, and health care costs among adults ≥65 years of age, which is the most rapidly growing segment of the U.S. METHODS: We prospectively investigated separate and combined associations of lifestyle risk factors with incident HF (1,380 cases) over 21.5 years among 4,490 men and women in the Cardiovascular Health Study, which is a community-based cohort of older adults. Lifestyle factors included 4 dietary patterns (Alternative Healthy Eating Index, Dietary Approaches to Stop Hypertension, an American Heart Association 2020 dietary goals score, and a Biologic pattern, which was constructed using previous knowledge of cardiovascular disease dietary risk factors), 4 physical activity metrics (exercise intensity, walking pace, energy expended in leisure activity, and walking distance), alcohol intake, smoking, and obesity. RESULTS: No dietary pattern was associated with developing HF (p > 0.05). Walking pace and leisure activity were associated with a 26% and 22% lower risk of HF, respectively (pace >3 mph vs. <2 mph; hazard ratio [HR]: 0.74; 95% confidence interval [CI]: 0.63 to 0.86; leisure activity ≥845 kcal/week vs. <845 kcal/week; HR: 0.78; 95% CI: 0.69 to 0.87). Modest alcohol intake, maintaining a body mass index <30 kg/m(2), and not smoking were also independently associated with a lower risk of HF. Participants with ≥4 healthy lifestyle factors had a 45% (HR: 0.55; 95% CI: 0.42 to 0.74) lower risk of HF. Heterogeneity by age, sex, cardiovascular disease, hypertension medication use, and diabetes was not observed. CONCLUSIONS: Among older U.S. adults, physical activity, modest alcohol intake, avoiding obesity, and not smoking, but not dietary patterns, were associated with a lower risk of HF.Role of the funding source: This research was supported by contracts HHSN268201200036C, HHSN268200800007C, N01 HC55222, N01HC85079, N01HC85080, N01HC85081, N01HC85082, N01HC85083, N01HC85086, and grant HL080295 from the National Heart, Lung, and Blood Institute (NHLBI), with additional contribution from the National Institute of Neurological Disorders and Stroke (NINDS). Additional support was provided by AG023629 from the National Institute on Aging (NIA). A full list of principal CHS investigators and institutions can be found at CHS-NHLBI.org. Fumiaki Imamura was supported by Medical Research Council Unit Programme number MC_UU_125015/5.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.jchf.2015.02.00
Effects of egg size on length, weight, growth and survival of prelarval and early feeding stage of Persian sturgeon (Acipenser persicus)
A study was conducted on the effects of egg size on length, weight, growth and survival of prelarval and early feeding stages of 19 female breeders of Persian sturgeon. The results showed that egg size can affect the total length and weight of prelarvae and there were positive and significant correlation between egg size and total length of prelarvae at the hatching stage and at 2,4,6,8 and 10 days post hatching (P<0.05). There were also positive and significant correlation between egg size and volume of yolk sac at hatching (P<0.05). However, during the first feeding stage the correlation between egg size and survival was very weak
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Genetic variation and temperature affects hybrid barriers during interspecific hybridization.
Genomic imprinting regulates parent-specific transcript dosage during seed development and is mainly confined to the endosperm. Elucidation of the function of many imprinted genes has been hampered by the lack of corresponding mutant phenotypes, and the role of imprinting is mainly associated with genome dosage regulation or allocation of resources. Disruption of imprinted genes has also been suggested to mediate endosperm-based post-zygotic hybrid barriers depending on genetic variation and gene dosage. Here, we have analyzed the conservation of a clade from the MADS-box type I class transcription factors in the closely related species Arabidopsis arenosa, A. lyrata, and A. thaliana, and show that AGL36-like genes are imprinted and maternally expressed in seeds of Arabidopsis species and in hybrid seeds between outbreeding species. In hybridizations between outbreeding and inbreeding species the paternally silenced allele of the AGL36-like gene is reactivated in the hybrid, demonstrating that also maternally expressed imprinted genes are perturbed during hybridization and that such effects on imprinted genes are specific to the species combination. Furthermore, we also demonstrate a quantitative effect of genetic diversity and temperature on the strength of the post-zygotic hybridization barrier. Markedly, a small decrease in temperature during seed development increases the survival of hybrid F1 seeds, suggesting that abiotic and genetic parameters play important roles in post-zygotic species barriers, pointing at evolutionary scenarios favoring such effects. OPEN RESEARCH BADGES: This article has earned an Open Data Badge for making publicly available the digitally-shareable data necessary to reproduce the reported results. The data is available at https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA562212. All sequences generated in this study have been deposited in the National Center for Biotechnology Information Sequence Read Archive (https://www.ncbi.nlm.nih.gov/sra/) with project number PRJNA562212
La légitimité des parties prenantes dans l'aménagement des villes : éthique de la conduite des projets urbains
Les projets urbains – appelés aussi projets d’aménagement urbain ou opérations d’aménagement – sont largement tributaires de la participation accrue d’une multitude de parties prenantes, dont les atouts pour le projet et les revendications vis-à -vis de celui-ci peuvent être complémentaires et/ou contradictoires. Dans ce contexte quel degré de priorité accorder à telle ou telle partie prenante ? Pour y parvenir, les porteurs d’un projet sont appelés à évaluer la légitimité de ces parties prenantes. Afin d’examiner ce concept, l’étude fait appel au croisement de textes issus de corpus théoriques autres que les corpus classiques de l’urbanisme et des études urbaines : ceux de la théorie des stakeholders dans le domaine du management organisationnel et de l’éthique des affaires ; du modèle des cités, ancré dans la sociologie pragmatique ; et des théories de la justice. Puis elle confronte les enseignements de ces théories à l’analyse empirique d’un cas pratique virtuel, créé pour les besoins de cette recherche. L’aller-retour entre la théorie et des mises en situation concrètes, mettant souvent en avant des tensions entre légitimités concurrentes, permet d’affiner les principes éthiques à la base de ces légitimités, selon une méthode inspirée de celle de l’équilibre réflexif. L’analyse montre que la légitimité d’une partie prenante résulte d’un raisonnement s’appuyant sur une norme d’efficacité ou sur une norme éthique, idéalement compatibles dans le cadre d’une éthique de responsabilité. Dans la première approche (l’efficacité) le porteur du projet sera principalement attentif aux capacités d’action des parties prenantes sur le projet, incluant la capacité de représentativité, les capacités légales (titres, droits, liens contractuels), les savoirs et savoir-faire (expertise, compétences), la créativité, les ressources matérielles et financières, et la capacité à engager. Dans la deuxième approche (éthique) le porteur de projet sera principalement attentif aux revendications légitimes des parties prenantes vis-à -vis du projet : les revendications de bien-être global, de capabilités (autonomie, libertés, possibilités offertes aux individus, avantages socio-économiques), de liens communautaires (valeurs et traditions), de bien-être d’autrui et les revendications environnementales. La recherche permet alors de faire émerger six principes éthiques pour l’évaluation de la légitimité : l’utilité globale, le respect de la liberté, l’équité, la solidarité (et la tolérance), le care et la responsabilité environnementale. Alors que les théories de l’urbanisme – dont l’un des objets principaux est pourtant l’analyse critique des processus de fabrication des villes – se sont peu intéressées aux principes normatifs à la base de ces processus, cette recherche propose un cadre conceptuel utile aux chercheurs et aux professionnels pour porter un jugement, notamment en termes éthiques, sur les décisions relatives à la prise en compte des parties prenantes dans les projets urbains. En faisant cela, elle contribue à jeter les bases d’une éthique de la conduite des projets urbains.Urban projects - also referred to as urban development projects - are largely dependent on the increased involvement of a multitude of stakeholders, whose assets for, and demands on, the project may be complementary and / or contradictory. In this context, how much priority should be given to different stakeholders? To answer this question, project leaders are called upon to assess the legitimacy of these stakeholders. To examine this concept, the study calls upon the crossing of texts from theoretical corpuses other than the classic corpus of urban planning and urban studies: those of stakeholder theory in the field of organizational management and business ethics; the model of the « cités », anchored in pragmatic sociology; and theories of justice. Then it confronts the lessons of these theories with the empirical analysis of a virtual practical case created for the purpose of this research. The round-trip between theory and concrete situations, often emphasizing tensions between competing legitimacies, makes it possible to refine the ethical principles underlying these legitimacies, through a method inspired by that of reflexive equilibrium. The analysis shows that the legitimacy of a stakeholder results from reasoning based on an efficiency standard or on an ethical standard, ideally compatible in the context of an ethics of responsibility. In the first approach (effectiveness) the proponent will be mainly attentive to the stakeholders' capacities for action on the project, including representativeness, legal capacities (titles, rights, contractual links), knowledge and know-how (expertise, skills), creativity, material and financial resources, and the ability to engage other stakeholders into the project. In the second (ethical) approach, the project proponent will be mainly attentive to the legitimate demands of stakeholders on the project: demands for global well-being, capability building (autonomy, freedoms, opportunities for individuals, socio-economic benefits), community ties (values ​​and traditions of large and small communities), well-being of others and environmental claims. The research then enables the emergence of six ethical principles for the assessment of legitimacies: global utility, respect for freedom, equity, solidarity (and tolerance), care and environmental responsibility. While the theories of planning and urban studies - one of the main objects of which is the critical analysis of the manufacturing processes of cities - have paid little attention to the normative principles underlying these processes, this research proposes a conceptual framework that is useful for researchers and professionals to make a judgment, especially in terms of ethics, on decisions concerning the consideration of stakeholders in urban projects. In doing so, it helps to lay the foundations for an ethic of the conduct of urban projects
Using sterile insect technique against Carob moth, Ectomyelois ceratoniae (Zeller) (Lep.: Pyralidae), in Yazd province, Iran
Carob moth, Ectomyelois ceratoniae (Zeller) (Lep.: Pyralidae), is the most important pest of pomegranate fruit in Iran where the cryptic activity of its larva makes the application of insecticides practically impossible. In this research, we evaluated the viability of the sterile insect technique against the carob moth in two isolated regions in Yazd province (Aqda and Mehriz). The mass rearing of the pest was performed in clean rooms on artificial diet under environmental conditions, 29±1 ºC and 75±5 %RH applying 165 Gy gamma ray as sterilizing doze. The sterile insects were released periodically in Aqda orchards (45 hectares) and in Chah Sheida (12 hectares) in Mehriz between March and November 2015. The infestation rate of carob moth in Aqda and Mehriz significantly reduced, in both target regions and control areas, by 12.27% and 44.02%, as well as 12.06% and 50.11%, for Aqda and Mehriz, respectively. It was concluded that periodical release of sterile carob moths can effectively lower the density of pest population and its economic loss on the harvest
Surprisingly Simple Mechanical Behavior of a Complex Embryonic Tissue
Background: Previous studies suggest that mechanical feedback could coordinate morphogenetic events in embryos. Furthermore, embryonic tissues have complex structure and composition and undergo large deformations during morphogenesis. Hence we expect highly non-linear and loading-rate dependent tissue mechanical properties in embryos. Methodology/Principal Findings: We used micro-aspiration to test whether a simple linear viscoelastic model was sufficient to describe the mechanical behavior of gastrula stage Xenopus laevis embryonic tissue in vivo. We tested whether these embryonic tissues change their mechanical properties in response to mechanical stimuli but found no evidence of changes in the viscoelastic properties of the tissue in response to stress or stress application rate. We used this model to test hypotheses about the pattern of force generation during electrically induced tissue contractions. The dependence of contractions on suction pressure was most consistent with apical tension, and was inconsistent with isotropic contraction. Finally, stiffer clutches generated stronger contractions, suggesting that force generation and stiffness may be coupled in the embryo. Conclusions/Significance: The mechanical behavior of a complex, active embryonic tissue can be surprisingly well described by a simple linear viscoelastic model with power law creep compliance, even at high deformations. We found no evidence of mechanical feedback in this system. Together these results show that very simple mechanical models can be useful in describing embryo mechanics. © 2010 von Dassow et al
Inter-seasonal compressed air energy storage using saline aquifers
Meeting inter-seasonal fluctuations in electricity production or demand in a system dominated by renewable energy requires the cheap, reliable and accessible storage of energy on a scale that is currently challenging to achieve. Commercially mature compressed-air energy storage could be applied to porous rocks in sedimentary basins worldwide, where legacy data from hydrocarbon exploration are available, and if geographically close to renewable energy sources. Here we present a modelling approach to predict the potential for compressed-air energy storage in porous rocks. By combining this with an extensive geological database, we provide a regional assessment of this potential for the United Kingdom. We find the potential storage capacity is equivalent to approximately 160% of the United Kingdom’s electricity consumption for January and February 2017 (77–96 TWh), with a roundtrip energy efficiency of 54–59%. This UK storage potential is achievable at costs in the range US$0.42–4.71 kWh−1
Polymorphism and magnetic properties of Li2MSiO4 (M 5 Fe, Mn) cathode materials
Transition metal-based lithium orthosilicates (Li2MSiO4,M=Fe, Ni, Co, Mn) are gaining a wide interest as
cathode materials for lithium-ion batteries. These materials present a very complex polymorphism that
could affect their physical properties. In this work, we synthesized the Li2FeSiO4 and Li2MnSiO4 compounds
by a sol-gel method at different temperatures. The samples were investigated by XRPD, TEM, 7Li MAS
NMR, and magnetization measurements, in order to characterize the relationships between crystal structure
and magnetic properties. High-quality 7Li MAS NMR spectra were used to determine the silicate structure,
which can otherwise be hard to study due to possible mixtures of different polymorphs. The magnetization
study revealed that the Neel temperature does not depend on the polymorph structure for both iron and
manganese lithium orthosilicates
ENCAPSULATION OF EXTRACT FROM WINERY INDUSTRY RESIDUE USING THE SUPERCRITICAL ANTI-SOLVENT TECHNIQUE
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