First critical field measurements of superconducting films by third harmonic analysis

The temperature behaviour of the first critical field ($B_{C1}$) of superconducting thin film samples can be determined with high accuracy using an inductive and contactless method. Driving a sinusoidal current in a single coil placed in front of the sample, a non zero third harmonic voltage $V_{3}$ is induced in it when Abrikosov vortices enter the sample. Conditions to be satisfied for the quantitative evaluation of $B_{C1}$ using this technique are detailed. As validation test, different type II superconductors (Nb, NbN, MgB$_{2}$ and Y$_{1}$Ba$_{2}$Cu$_{3}$O$_{7-d}$ under the form of thin films) have been measured. The comparison between experimental results, data presented in literature and theoretical predictions is presented and discussed.Comment: to be published in Journal of Applied Physic

Metals loads into the Mediterranean Sea: estimate of Sarno River inputs and ecological risk

The metals pollution in the Sarno River and its environmental impact on the Gulf of Naples (Tyrrhenian Sea, Central Mediterranean Sea) were estimated. Eight selected metals (As, Hg, Cd, Cr, Cu, Ni, Pb and Zn) were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediment samples. Selected metals concentrations ranged from 0.32 to 1,680.39 μg l(-1) in water DP, from 103.6 to 7,734.6 μg l(-1) in SPM and from 90.7 to 2,470.3 mg kg(-1) in sediment samples. Contaminant discharges of selected metals into the sea were calculated in about 13,977.6 kg year(-1) showing that this river should account as one of the main contribution sources of metals to the Tyrrhenian Sea

School feeding or general food distribution? Quasi-experimental evidence on the educational impacts of emergency food assistance during conflict in Mali

This study relies on a unique precrisis baseline and five-year follow-up to investigate the effects of emergency school feeding and generalised food distribution (GFD) on children’s schooling during conflict in Mali. It estimates programme impact on child enrolment, absenteeism, and attainment by using a difference in differences weighted estimator. School feeding led to increases in enrolment by 10 percentage points and to around an additional half-year of completed schooling. Attendance among boys in households receiving GFD, however, declined by about 20 per cent relative to the comparison group. Disaggregating by conflict intensity showed that receipt of any food assistance led to a rise in enrolment mostly in high-intensity conflict areas and that the negative effects of GFD on attendance were also concentrated in the most affected areas. School feeding mostly raised attainment among children in areas not in the immediate vicinity of conflict. Programme receipt triggered adjustments in child labour. School feeding led to lower participation and time spent in work among girls, while GFD raised children’s labour, particularly among boys. The educational implications of food assistance should be considered in planning humanitarian responses to bridge the gap between emergency assistance and development by promoting children’s education

Experimental evidence of s-wave superconductivity in bulk CaC6_{6}

The temperature dependence of the in-plane magnetic penetration depth, $\lambda_{ab}(T)$, has been measured in a c-axis oriented polycrystalline CaC$_{6}$ bulk sample using a high-resolution mutual inductance technique. A clear exponential behavior of $\lambda_{ab}(T)$ has been observed at low temperatures, strongly suggesting isotropic s-wave pairing. Data fit using the standard BCS theory yields $\lambda_{ab}(0)=(720\pm 80)$ Angstroem and $\Delta(0)=(1.79\pm 0.08)$ meV. The ratio $2\Delta(0)/k_{_B}T_{c}=(3.6\pm 0.2)$ gives indication for a conventional weakly coupled superconductor.Comment: To appear in Phys. Rev. Let

Intrinsic nonlinearity probed by intermodulation distortion microwave measurements on high quality MgB2 thin films

The two tone intermodulation distortion arising in MgB2 thin films synthesized by hybrid physical-chemical vapour deposition is studied in order to probe the influence of the two bands on the nonlinear response of this superconductor. The measurements are carried out by using a dielectrically loaded copper cavity operating at 7 GHz. Microwave data on samples having critical temperatures above 41 K, very low resistivity values, and residual resistivity ratio larger than 10, are shown. The dependence of the nonlinear surface losses and of the third order intermodulation products on the power feeding the cavity and on the temperature is analyzed. At low power, the signal arising from distortion versus temperature shows the intrinsic s-wave behavior expected for this compound. Data are compared with measurements performed on Nb and YBCO thin films using the same technique.Comment: Revised version. Submitted to APL on October 7th 200

Puberty in breeds of female hair sheep in Northeast Brazil

Analisou-se o desempenho de 112 borregas Morada Nova (32), Somalis Brasileira (63) e Santa Inês (17), mantidas em pastagem nativa, no Centro Nacional de Pesquisa de Caprinos (CNPC), em Sobral, CE, Nordeste do Brasil (latitude 3° 42' Sul e longitude em 40° 21' Oeste). Desmamadas a idade média de 112 dias, foram pesadas ao nascer e a cada 28 dias, até à puberdade e observadas com vistas à detecção da ocorrência de estro, durante duas vezes ao dia, com auxílio de rufiões. Entre 40 e 60 horas após a borrega ser identificada em estro, era submetida à laparotomia, como objetivo de se avaliar a função ovariana quanto à ocorrência e à taxa de ovulação nos períodos pré-puberal e puberal. A idade e o peso médio à puberdade foram de 306,3 ± 5,6 dias e de 20,7 ± 0,3 kg, respectivamente. A raça Santa Inês (24,0 ± 1,0 kg) foi estatisticamente mais pesada (P 0,05), porém observou-se efeito de ano (P 0,05) entre raças. Durante o período pré-puberal, 78,35% das borregas ovularam com uma taxa de 1,13.This experiment was carried out with 112 ewe lambs, 32 of Morada Nova breed (MN), 63 Brazilian Somali (BS), and 17 Santa Inês (SI); grazing in native pasture at the Brazilian National Goat Research Center, CNPC, Sobral, CE, Northeast Brazil (3° 42' south latitude and 40° 21' west longitude). Lambs were weaned in groups averaging 112 days of age. Live body weights were recorded at birth and at four-week intervals until the first puberal estrus. Estrus was detected by using Leaser rams. The date, time of day and live body weights were recorded to obtain the age and weight at first puberal estrus. Between 40 to 60 hours after estrus was detected, the ovaries of each ewe lamb were observed by laparotomy to determine the occurrence and rate of prepuberal (CA) and puberal (CL) ovulations. The overall mean age and weight at puberty were 306.3 ± 5.6 days and 20.7 ± 0.3 kg, respectively. The SI breed (24.0 ± 1.0 kg) was statistically (P 0.05) among breeds for age at puberty. There was no statistical difference (P> 0.05) for weight or age at puberty due to type of birth. A significant (P 0.05) were found among breeds for incidence and rate of ovulation. All ewe lambs ovulated at puberal estrus with a mean ovulation rate of 1.31. During prepuberal period, 78.35% of the ewe lambs ovulated with an ovulation rate of 1.13

Traditional system of goat management. III. Reproductive performance of SRD (non-descript) does and kid mortality

Avaliou-se o desempenho de 50 fêmeas de cabras SRD adultas mantidas em um piquete de pastagem nativa com uma lotação de 1 a 1,5 ha/cab/ano. Neste rebanho, dois reprodutores foram usados em monta natural de setembro de 1978 a dezembro de 1980. Foram observados 93 partos e 28 abortos. Ocorreram três prenhezes antes do início do experimento. Dos 90 partos restantes, 57,1%, 35,6%, 1,1% e 5,6% forem simples, duplos, triplos e não determinados, respectivamente. O rebanho mostrou uma prolificidade de 1,38. Para o rebanho inicial 15 (30%), 28 (56%),  5 (10%) e 2 (4%) das cabras pariram uma, duas, três e nenhuma vez, respectivamente, durante o período estudado. O período de gestação e o intervalo entre os partos não foram influenciados pelo tipo de nascimento. O período vazio foi influenciado pela estação do ano, quando os dados foram classificados por estação e tipo de parto. A combinação do tipo de parto, na parição inicial e na parição seguinte, teve influência significativa no período vazio. Os animais que pariram primeiramente simples e depois simples ou duplos apresentaram um período vazio menor (109 vs 188 dias) do que os animais que pariram primeiramente múltiplos e depois abortaram na prenhez seguinte. O pique de mortalidade (32%) ocorreu entre 7 e 112 dias de idade. A mortalidade de cabritos parece não ter sido influenciada pelo sexo e tipo de nascimento. A mortalidade total das crias foi de 76%. A idade à morte desses animais foi influenciada pela estação, sexo e interação de ambos. Os machos nascidos durante a estação chuvosa sobreviveram mais tempo do que os nascidos nas outras classes estudadas.The reproductive performance of 50 adult SRD does maintained in native caatinga pasture at a stocking rate of 1 to 1.5 ha/head/year was evaluated. Two bucks were used in natural matings from September 1978 until December 1980. A total of 93 kiddings and 28 abortions occurred. Three pregnancies occurred before initiation of the experiment. From the 90 parturitions, 57.7%, 35.6%, 1.1% and 5.6% bore singles, twins, triplets and undetermined, respectively. The flock showed an overall prolificacy of 1.38. From the initial flock, 15 (30%), 28 (56%), 5 (10%) and 2 (4%) does presented one, two, three and zero kiddings, respectively, during the period of study. Neither gestation length nor kidding interval were influenced by type of birth. Length of open period was influenced by season of the year when data were classified by season and kidding status at the open period. Combination of kidding type at previous and following kiddings showed a significant influence (P < 0.05) on the length of the open period. Animals that kidded first singles and then singles or twins showed a shorter open period than animals that firstly kidded twins and then aborted at the following pregnancy (109 vs 188 days). The peak of kid mortality occurred between 7 and 112 days of age. Kid mortality appears not to be influenced by sex or type of birth. Overall kid mortality was 76%. The age at death of kids was influenced by season and sex as well as by their interaction. Males born during the rainy season survived longer than any other class studied.

Reversible metal-insulator transition of Ar-irradiated LaAlO₃/SrTiO₃ interfaces

The conducting state of a quasi-two-dimensional electron gas (q2DEG), formed at the heterointerface between the two wide-bandgap insulators LaAlO₃ (LAO) and SrTiO₃, can be made completely insulating by low-energy, 150-eV, Ar⁺ irradiation. The metallic behavior of the interface can be recovered by high-temperature oxygen annealing. The electrical transport properties of the recovered q2DEG are exactly the same as before the irradiation. Microstructural investigations confirm that the transition is not due to physical etching or crystal lattice distortion of the LAO film below its critical thickness. They also reveal a correlation between electrical state, LAO film surface amorphization, and argon ion implantation. The experimental results are in agreement with density functional theory calculations of Ar implantation and migration in the LAO film. This suggests that the metal-insulator transition may be caused by charge trapping in the defect amorphous layer created during the ion irradiation

A longitudinal study on BIO14.6 hamsters with dilated cardiomyopathy: micro-echocardiographic evaluation

<p>Abstract</p> <p>Background</p> <p>In recent years, several new technologies for small-animal imaging have been developed. In particular, the use of ultrasound in animal imaging has focused on the investigation of accessible biological structures such as the heart, of which it provides a morphological and functional assessment. The purpose of this study was to investigate the role of micro-ultrasonography (μ-US) in a longitudinal study on BIO14.6 cardiomyopathic hamsters treated with gene therapy.</p> <p>Methods</p> <p>Thirty hamsters were divided into three groups (n = 10): Group I, untreated BIO 14.6 hamsters; Group II, BIO 14.6 hamsters treated with gene therapy; Group III, untreated wild type (WT) hamsters. All hamsters underwent serial μ-US sessions and were sacrificed at predetermined time points.</p> <p>Results</p> <p>μ-US revealed: in Group I, progressive dilation of the left ventricle with a change in heart morphology from an elliptical to a more spherical shape, altered configuration of the mitral valve and subvalvular apparatus, and severe reduction in ejection fraction; in Group II, mild decrease in contractile function and ejection fraction; in Group III, normal cardiac chamber morphology and function. There was a negative correlation between the percentage of fibrosis observed at histology and the ejection fraction obtained on μ-echocardiography (Spearman r: -0.839; p < 0.001).</p> <p>Conclusions</p> <p>Although histological examination remains indispensable for a conclusive diagnosis, high-frequency μ-echocardiography, thanks to the high spatial and contrast resolution, can be considered sufficient for monitoring therapeutic efficacy and/or the progression of dilated cardiomyopathy, providing an alternative tool for repeatable and noninvasive evaluation.</p

Roads to interdisciplinarity - working at the nexus among food systems, nutrition and health: 1st annual Agriculture, Nutrition and Health (ANH) Academy Week, Addis Ababa (Ethiopia), 20-24 June 2016

The development agenda over the next 15 years will be framed by the Sustainable Development Goals (SDGs), of which more than half relate either directly or indirectly to the agricultural sector, highlighting its importance in economic growth and development of low- and middle-income countries (LMICs) (FAO 2015). It is therefore imperative that agricultural systems are better understood, so that they may be strengthened and optimised to deliver outcomes in line with the SDGs. The interface between agriculture, nutrition and health is particularly multifaceted and complex, and the development of successful strategies will require an integrated and multi-sectoral approach (Dorward and Dangour 2012; Jones and Ejeta 2016). ‘Agri-health’ is an evolving paradigm seeking to unify research approaches and methodologies between agriculture and health. Research within the field encapsulates a broad range of disciplines, locations and actors, and aligns these into a common research agenda. In doing so, agri-health aims to transcend barriers imposed by the longstanding institutional and disciplinary silos. Much progress has been made in recent years in this regard (Harris et al. 2013; Kanter et al. 2014; Picchioni et al. 2015). However, more coordinated efforts are required to generate consensus and target strategic priorities amongst the many existing information gaps (Webb and Kennedy 2014). Understanding the linkages between complex issues such as globalisation, climate change, food systems, and evolving burdens of malnutrition is central to agri-health research. The Leverhulme Centre for Integrative Research on Agriculture and Health (LCIRAH) was created in 2010 with a key focus on agri-health interdisciplinary research. LCIRAH includes experts from across the member colleges of the University of London: the London School of Hygiene and Tropical Medicine (LSHTM), the School of Oriental and African Studies (SOAS), and the Royal Veterinary College (RVC). The Agriculture, Nutrition and Health Academy (ANH Academy), was established in 2015 as a platform to facilitate learning, knowledge sharing, capacity building and collaborative partnerships among the growing global community of researchers, practitioners and policy makers working within agri-health. It was developed with support from the Innovative Metrics and Methods for Agriculture and Nutrition Actions (IMMANA) research programme,Footnote1 led by LCIRAH and Tufts University, in partnership with the CGIAR Programme on Agriculture for Nutrition and Health (A4NH). Within this scope, the ANH Academy hosts an annual ANH Academy Week, building on the legacy of five agri-health research conferences organised by LCIRAH; as well as events and activities coordinated under the CGIAR A4NH. The inaugural ANH Academy Week took place in Addis Ababa, Ethiopia, in June 2016 and included two days of interactive ‘learning labs’ (training sessions on skills and methods across a broad range of disciplines in agri-health), followed by a three-day research conference. The conference included a mix of abstract-driven sessions, round table discussions, and keynote speeches from across the spectrum of agriculture, nutrition and health disciplines, and a wide range of countries. Hawkes et al. (2012) developed a conceptual framework (Fig. 2, hereafter referred to as the Framework), outlining the key pathways through which agriculture may affect nutritional status in Low and Middle Income Countries (LMICs), as well as broader drivers of these pathways. Drawing on this Framework, this paper aims to provide an analytical synthesis of the ANH Academy week by mapping the research and debates presented during the conference