Magnetic Studies on Spinel Ferrite Nanoparticles and Bulk Samples Synthesized by Citrate Combustion Route

We report structural, microstructural and magnetic studies of ZnFe2O4, MnFe2O4 and mixed Mn-Ni-Zn ferrites in nanoparticles and bulk forms. Polycrystalline samples were prepared by citrate combustion synthesis, which resulted in homogeneous and nanograin powders. Particle sizes estimated from the XRD and SEM were found to be below 100 nm for the calcined powders (600 degrees C) and above 300 nm range for the sintered (1200 degrees C) samples. Substitution of Ni and Zn for Mn enhanced the saturation magnetization and coercivity, because of the redistribution between octahedral and tetrahedral iron sites. Curie temperature were found to be higher for the calcined powders as compared to corresponding sintered samples due to particle size effects

The computer in a roofing slate quarry

[Resumen] Sencillas configuraciones informáticas en base a ordenadores personales con programas comerciales de modelización y diseño asistido por ordenador, facilitan el reiterativo trabajo de planificación minera de una explotación de pizarra a cielo abierto. Su utilización es aplicable a tres fases del proyecto minero: Modelización del yacimiento (investigación), proyecto de explotación (viabilidad) y labores mineras (ejecución).[Abstract] Simple integrated systems based on personal computers and cornmercial programmes about modelling and CAD, make easy the reiterative work on exploitation planning in roofing slate quarries. We can use this systems in the three phases of the mining project: bed modelling (Research), exploitation (Viability)wand mining (Performance)

Placing the Fijian Honeyeaters within the meliphagid radiation: implications for origins and conservation

Understanding the evolutionary relationships of threatened species provides an important framework for making decisions about their conservation. However, unrecognised problems with the underlying phylogenetic analyses may bias the decision-making process. Recent phylogenetic studies have improved our understanding of Meliphagidae, but also indicate discordance between molecular datasets. Here, we examine the causes of this discordance using maximum likelihood tree-building and network analyses of identically sampled datasets for four genetic loci. Our results suggest that while we can be reasonably confident of relationships within species groups, discordance within and between molecular datasets tends to obscure relationships towards the base of the meliphagid tree. This ongoing uncertainty likely reflects differences in the sampling of markers and taxa between previously published analyses. To avoid the problems of conflicting data we used divergence time analyses of only the most densely sampled marker, NADH-ubiquinone oxidoreductase chain 2, to investigate the age and origins of the Fijian Meliphagidae. Our analyses suggest two temporally distinct colonisations of the Fijian archipelago. The large-bodied honeyeaters arrived ,15.6 million years ago, subsequently diversifying and spreading to Tonga and Samoa. In contrast, Myzomela appears to have arrived within the last 5.0 million years. The phylogenetic results therefore imply that conserving the evolutionary diversity of Meliphagidae in Polynesia requires that effort be spread across both the currently recognised taxa and geographical range

Annulment of Oil Licences in Nigeria’s Upstream Petroleum Sector: A Legal Critique of the Costs and Benefits

Owing to various reasons, tenable and untenable, successive governments in Nigeria have annulled licenses duly granted to identifiable upstream petroleum operators. With due sense of circumspect, when irregularities manifest in the process and the grant of substantive licences, such does not vest in the government an unfettered right to annul the licence. There are evidences of such occurrence in spite of established procedures regulating annulments, commonly referred to as revocation or cancellation. This paper is a critique of the annulment of oil licenses and the associated contractualregulatory dimensions. The validity of the Federal Government’s actions also comes to the fore, particularly in the light of renewed drive to attract investments into the upstream sector. Thus, as some benefits are accruable to the players, it is also important to appraise the consequential costs attributable to undue annulment of oil licenses. The paper adopts a descriptive analytical method of available facts, expounds requisite statutory provisions and utilizes judicial precedents to highlight the context of the study. It is imperative that the Federal Government adheres to established procedures on oil license annulment, as a contrary posture will amount to several negative outcomes

Воспитание толерантности в процессе преподавания гуманитарных дисциплин

Objective: To assess whether patient characteristics add to the fetal fibronectin test and cervical length measurement in the prediction of preterm delivery in symptomatic women. Study design: A nationwide prospective cohort study was conducted in all ten perinatal centres in the Netherlands. Women with symptoms of preterm labour between 24 and 34 weeks gestation with intact membranes were invited. In all women qualitative fibronectin testing (0.050 tig/mL cut-off) and cervical length measurement were performed. Only singleton pregnancies were included in this analysis. Logistic regression was used to construct two multivariable models to predict spontaneously delivery within 7 days: a model including cervical length and fetal fibronectin as predictors, and an extended model including all potential predictors. The models were internally validated using bootstrapping techniques. Predictive performances were assessed as the area under the receiver operator characteristic curve (AUC) and calibration plots. We compared the models' capability to identify women with a low risk to deliver within 7 days. A risk less than 5%, corresponding to the risk for women with a cervical length of at least 25 mm, was considered as low risk. Results: Seventy-three of 600 included women (12%) had delivered spontaneously within 7 days. The extended model included maternal age, parity, previous preterm delivery, vaginal bleeding, C-reactive protein, cervical length, dilatation and fibronectin status. Both models had high discriminative performances (AUC of 0.92 (95% CI 0.88-0.95) and 0.95 (95% CI 0.92-0.97) respectively). Compared to the model with fibronectin and cervical length, our extended model reclassified 38 women (6%) from low risk to high risk and 21 women (4%) from high risk to low risk. Preterm delivery within 7 days occurred once in both the reclassification groups. Conclusion: In women with symptoms of preterm labour before 34 weeks gestation, a model that integrates maternal characteristics, clinical signs and laboratory tests, did not predict delivery within 7 days better than a model with only fibronectin and cervical length. (C) 2015 Elsevier Ireland Ltd. All rights reserved

CapZ-lipid membrane interactions: a computer analysis

BACKGROUND: CapZ is a calcium-insensitive and lipid-dependent actin filament capping protein, the main function of which is to regulate the assembly of the actin cytoskeleton. CapZ is associated with membranes in cells and it is generally assumed that this interaction is mediated by polyphosphoinositides (PPI) particularly PIP(2), which has been characterized in vitro. RESULTS: We propose that non-PPI lipids also bind CapZ. Data from computer-aided sequence and structure analyses further suggest that CapZ could become partially buried in the lipid bilayer probably under mildly acidic conditions, in a manner that is not only dependent on the presence of PPIs. We show that lipid binding could involve a number of sites that are spread throughout the CapZ molecule i.e., alpha- and beta-subunits. However, a beta-subunit segment between residues 134–151 is most likely to be involved in interacting with and inserting into lipid membrane due to a slighly higher ratio of positively to negatively charged residues and also due to the presence of a small hydrophobic helix. CONCLUSION: CapZ may therefore play an essential role in providing a stable membrane anchor for actin filaments

Life and living in advanced age: a cohort study in New Zealand - Te Puāwaitanga o Nga Tapuwae Kia Ora Tonu, LiLACS NZ: Study protocol

The number of people of advanced age (85 years and older) is increasing and health systems may be challenged by increasing health-related needs. Recent overseas evidence suggests relatively high levels of wellbeing in this group, however little is known about people of advanced age, particularly the indigenous Māori, in Aotearoa, New Zealand. This paper outlines the methods of the study Life and Living in Advanced Age: A Cohort Study in New Zealand. The study aimed to establish predictors of successful advanced ageing and understand the relative importance of health, frailty, cultural, social & economic factors to successful ageing for Māori and non-Māori in New Zealand

Quantifying Earth system interactions for sustainable food production via expert elicitation

Several safe boundaries of critical Earth system processes have already been crossed due to human perturbations; not accounting for their interactions may further narrow the safe operating space for humanity. Using expert knowledge elicitation, we explored interactions among seven variables representing Earth system processes relevant to food production, identifying many interactions little explored in Earth system literature. We found that green water and land system change affect other Earth system processes strongly, while land, freshwater and ocean components of biosphere integrity are the most impacted by other Earth system processes, most notably blue water and biogeochemical flows. We also mapped a complex network of mechanisms mediating these interactions and created a future research prioritization scheme based on interaction strengths and existing knowledge gaps. Our study improves the understanding of Earth system interactions, with sustainability implications including improved Earth system modelling and more explicit biophysical limits for future food production