135 research outputs found
Tuning the redox properties of metalloporphyrin-and metallophthalocyanine-based molecular electrodes for the highest electrocatalytic activity in the oxidation of thiols
In this work we discuss different approaches for achieving electrodes modified with N4 macrocyclic complexes for the catalysis of the electrochemical oxidation of thiols. These approaches involve adsorption, electropolymerization and molecular anchoring using self assembled monolayers. We also discuss the parameters that determine the reactivity of these complexes. Catalytic activity is associated with the nature of the central metal, redox potentials and Hammett parameters of substituents on the ligand. Correlations between catalytic activity (log i at constant E) and the redox potential of catalysts for complexes of Cr, Mn, Fe, Co, Ni and Cu are linear with an increase of activity for more positive redox potentials. For a great variety complexes bearing the same metal center (Co) correlations between log i and Eo′ of the Co(II)/Co(I) couple have the shape of an unsymmetric volcano. This indicates that the potential of the Co(II)/Co(I) couple can be tuned using the appropiate ligand to achieve maximum catalytic activity. Maximum activity probably corresponds to a ΔG of adsorption of the thiol on the Co center equal to zero, and to a coverage of active sites by the thiol equal to 0.5
Mathematical Modelling and Identification of a Quadrotor
Motivated by the important growth of VTOL vehicles research such as quadrotors and to a small extent autonomous flight, a quadrotor dynamical model is presented in this work. The purpose of this study is to get a better understanding of its flight dynamics. It is an underactuated system. So, a simplified and clear model is needed to implement controllers on these kind of unmanned aerial systems. In addition, a computational tool is used for validation purposes. For future works embedded or intelligent control systems can be developed to control them. Gyroscopic and some aerodynamics effects are neglected
Out of Sight but Not Out of Mind? Behavioral Coordination in Red-Tailed Sportive Lemurs (Lepilemur ruficaudatus)
Many animals are organized into social groups and have to synchronize their activities to maintain group cohesion. Although activity budgets, habitat constraints, and group properties may impact on behavioural synchrony, little is known regarding how members of a group reach a consensus on the timing of activities such as foraging bouts. Game theory predicts that pair partners should synchronize their activities when there is an advantage of foraging together. As a result of this synchronization, differences in the energetic reserves of the two players develop spontaneously and the individual with lower reserves emerges as a pacemaker of the synchrony. Here, we studied the behavioral synchrony of pair-living, nocturnal, red-tailed sportive lemurs (Lepilemur ruficaudatus). We observed 8 pairs continuously for ≥1 annual reproductive cycle in Kirindy Forest, Western Madagascar. During focal observations, one observer followed the female of a pair and, simultaneously, another observer followed the male. We recorded the location and behavioral state of the focal individual every 5 min via instantaneous sampling. Although behavioral synchrony of pair partners appeared to be due mainly to endogenous activity patterns, they actively synchronized when they were in visual contact (<10 m). Nevertheless, red-tailed sportive lemurs benefit from synchronizing their activity only for 15% of the time, when they are close together. The lack of an early warning system for predators and weak support for benefits via social information transfer in combination with energetic constraints may explain why red-tailed sportive lemurs do not spend more time together and thus reap the benefits of behavioral synchrony
Identification of Circulating Proteins associated With General Cognitive Function among Middle-Aged and Older adults
Identifying circulating proteins associated with cognitive function may point to biomarkers and molecular process of cognitive impairment. Few studies have investigated the association between circulating proteins and cognitive function. We identify 246 protein measures quantified by the SomaScan assay as associated with cognitive function (p \u3c 4.9E-5, n up to 7289). Of these, 45 were replicated using SomaScan data, and three were replicated using Olink data at Bonferroni-corrected significance. Enrichment analysis linked the proteins associated with general cognitive function to cell signaling pathways and synapse architecture. Mendelian randomization analysis implicated higher levels of NECTIN2, a protein mediating viral entry into neuronal cells, with higher Alzheimer\u27s disease (AD) risk (p = 2.5E-26). Levels of 14 other protein measures were implicated as consequences of AD susceptibility (p \u3c 2.0E-4). Proteins implicated as causes or consequences of AD susceptibility may provide new insight into the potential relationship between immunity and AD susceptibility as well as potential therapeutic targets
Cross-Sectional Analysis of Late HAART Initiation in Latin America and the Caribbean: Late Testers and Late Presenters
Background: Starting HAART in a very advanced stage of disease is assumed to be the most prevalent form of initiation in HIV-infected subjects in developing countries. Data from Latin America and the Caribbean is still lacking. Our main objective was to determine the frequency, risk factors and trends in time for being late HAART initiator (LHI) in this region. Methodology: Cross-sectional analysis from 9817 HIV-infected treatment-naive patients initiating HAART at 6 sites (Argentina, Chile, Haiti, Honduras, Peru and Mexico) from October 1999 to July 2010. LHI had CD4 count 200cells/mm prior to HAART. Late testers (LT) were those LHI who initiated HAART within 6 months of HIV diagnosis. Late presenters (LP) initiated after 6 months of diagnosis. Prevalence, risk factors and trends over time were analyzed. Principal Findings: Among subjects starting HAART (n = 9817) who had baseline CD4 available (n = 8515), 76% were LHI: Argentina (56%[95%CI:52–59]), Chile (80%[95%CI:77–82]), Haiti (76%[95%CI:74–77]), Honduras (91%[95%CI:87–94]), Mexico (79%[95%CI:75–83]), Peru (86%[95%CI:84–88]). The proportion of LHI statistically changed over time (except in Honduras) (; Honduras p = 0.7), with a tendency towards lower rates in recent years. Males had increased risk of LHI in Chile, Haiti, Peru, and in the combined site analyses (CSA). Older patients were more likely LHI in Argentina and Peru (OR 1.21 per +10-year of age, 95%CI:1.02–1.45; OR 1.20, 95%CI:1.02–1.43; respectively), but not in CSA (OR 1.07, 95%CI:0.94–1.21). Higher education was associated with decreased risk for LHI in Chile (OR 0.92 per +1-year of education, 95%CI:0.87–0.98) (similar trends in Mexico, Peru, and CSA). LHI with date of HIV-diagnosis available, 55% were LT and 45% LP. Conclusion: LHI was highly prevalent in CCASAnet sites, mostly due to LT; the main risk factors associated were being male and older age. Earlier HIV-diagnosis and earlier treatment initiation are needed to maximize benefits from HAART in the region
Connecting the data landscape of long-term ecological studies: The SPI-Birds data hub
The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-term studies of birds, we have created the SPI-Birds Network and Database (www.spibirds.org)\u2014a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI-Birds has recruited over 120 members, and currently hosts data on almost 1.5 million individual birds collected in 80 populations over 2,000 cumulative years, and counting. SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by the principles of Findable, Accessible, Interoperable and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language). The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such as ours, COMADRE for animal demography, etc.) will aid much-needed large-scale ecological data integration
Prospección fitosanitaria en sistemas productivos hortícolas del cinturón verde de Córdoba (CVC).
La producción hortícola de la zona periurbana de la Ciudad de Córdoba (Cinturón Verde de
Córdoba-CVC) se encuentra en franco retroceso. Unas de sus principales limitantes son las
enfermedades y plagas, cuyo manejo adecuado y eficiente depende de la correcta identificación
del organismo causal. En un trabajo interdisciplinario e interinstitucional, se realizó un
relevamiento fitopatológico en fincas de productores fruti-hortícolas del CVC con diferentes
planteos productivos. Como resultado, se identificaron los agentes causales de las
enfermedades fúngicas y virales más frecuentes, como así también la entomofauna vinculada a
la producción hortícola en el CVC. La información sistematizada será puesta a disposición de los
productores a través de cartillas con fotos e información biológica y técnica, que constituya una
herramienta útil para la identificación y manejo adecuado de los diferentes agentes biológicos.Instituto de Patología VegetalFil: Pastor, Silvina Estela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Arguello Caro, Evangelina Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Di Feo, Liliana Del Valle. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Perez Grosso, Tomas. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Pérez, A. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Prado, A. Ministerio de Agricultura, Ganadería y Pesca. Subsecretaria de Agricultura Familiar. Delegación Córdoba; ArgentinaFil: Narmona, L. Ministerio de Agricultura, Ganadería y Pesca. Subsecretaria de Agricultura Familiar. Delegación Córdoba; ArgentinaFil: Scifo, A. Ministerio de Agricultura, Ganadería y Pesca. Subsecretaria de Agricultura Familiar. Delegación Córdoba; ArgentinaFil: Vaghi Medina, Carlos Gaston. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Serra, G. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Fichetti, P. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Barbero, G. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Alemandri, Vanina Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Celli, Marcos Giovani. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Celli, Marcos Giovani. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Perotto, Maria Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Rodriguez Pardina, Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Zanini, Andrea Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zanini, Andrea Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Giolitti, Fabian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Trucco, Veronica Milagros. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Nome Docampo, Claudia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Dal Zotto, Angelica. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Benitez, Roger Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Agencia De Extensión Rural Córdoba; Argentin
SELNET clinical practice guidelines for bone sarcoma
Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context
Role of age and comorbidities in mortality of patients with infective endocarditis
[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality.
[Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk.
[Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality.
[Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group
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