3,448 research outputs found

    Bone health in children and youth with Cystic Fibrosis: a systematic review and meta-analysis of matched cohort studies

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordObjective To assess the evidence regarding the differences in areal bone mineral density (aBMD) between children and adolescents with cystic fibrosis (CF) compared with their healthy peers, based on data from longitudinal studies. Study design We searched MEDLINE, SPORTDiscus, the Cochrane Library, PEDro (Physiotherapy Evidence Database), and Embase databases. Observational studies addressing the change of aBMD in children with CF and healthy children and adolescents were eligible. The DerSimonian and Laird method was used to compute pooled estimates of effect sizes (ES) and 95% CIs for the change of whole body (WB), lumbar spine (LS), and femoral neck (FN) aBMD. Results Six studies with participants with CF and 26 studies with healthy participants were included in the systematic review and meta-analysis. For the analysis in children with CF, the pooled ES for the change of WB aBMD was 0.29 (95% CI –0.15 to 0.74), for the change of LS aBMD was 0.13 (95% CI –0.16 to 0.41), and for the change of FN aBMD was 0.09 (95% CI –0.39 to 0.57). For the analysis in healthy children, the pooled ES for the change of WB aBMD was 0.37 (95% CI 0.26-0.49), for the change of LS aBMD was 0.13 (95% CI –0.16 to 0.41), and for the change of FN aBMD was 0.52 (95% CI 0.19-0.85). Conclusions aBMD development might not differ between children and adolescents with CF receiving medical care compared with their healthy peers. Further longitudinal studies in a CF population during growth and development are required to confirm our findings

    The use of cosmic muons in detecting heterogeneities in large volumes

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    The muon intensity attenuation method to detect heterogeneities in large matter volumes is analyzed. Approximate analytical expressions to estimate the collection time and the signal to noise ratio, are proposed and validated by Monte Carlo simulations. Important parameters, including point spread function and coordinate reconstruction uncertainty are also estimated using Monte Carlo simulations.Comment: 8 pages, 11 figures, submetted to NIM

    Caracterización del suministro de agua marina desalinizada para riego en el sureste español

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    Comunicación presentada al XXXVII Congreso Nacional de Riegos, celebrado en Don Benito del 4 al 6 de Junio de 2019 y organizada por la Asociación Española de Riegos y Drenajes y la Universidad de ExtremaduraLa actual escasez de recursos hídricos en las regiones áridas y semiáridas del sureste español ha impulsado la utilización de fuentes no convencionales, como la reutilización de aguas regeneradas y la desalinización de agua marina, especialmente en la agricultura de regadío. Como consecuencia, en esta región se está utilizando para riego agrícola casi el 100% del volumen de agua regenerada (105 hm3/año), así como cerca de 180 hm3/año de Agua Marina Desalinizada (AMD). Este trabajo describe la situación del suministro de AMD para riego en el sureste español, una región donde hasta el momento ha tenido un gran desarrollo. Se analizan en primer lugar los factores que justifican esta nueva alternativa de suministro hídrico para el regadío como estrategia para garantizar la producción de alimentos y el desarrollo socioeconómico regional. A continuación, se abordan cuestiones clave para analizar la sostenibilidad ambiental y económica del suministro de AMD en el medio y largo plazo, como son el consumo energético asociado a su producción y distribución, los costes asociados, y el precio final que tienen que asumir los agricultores.• Ministerio de Economía y Competitividad y el Fondo Europeo de Desarrollo Regional: Proyecto RIDESOST (AGL2017-85857-C2-2-R) • Programa LIFE de la Unión Europea: Proyecto DESEACROP (LIFE16-ENV_ES_000341

    Impact of Controlling the Site Distribution of Al Atoms on Catalytic Properties in Ferrierite-Type Zeolites

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    Zeolites with the ferrierite (FER) topology are synthesized using a combination of tetramethylammonium (TMA) cations with differently sized cyclic amines (pyrrolidine (Pyr), hexamethyleneimine (HMI), and 1,4- diazabicyclo[2.2.2]octane (DAB)). Using these organic structure-directing agents (SDAs), low Si/Al ratios and concentrated synthesis mixtures favor the crystallization of FER materials. Increasing the size of the cyclic amine or decreasing the aluminum content leads to the crystallization of other phases or the creation of excessive amounts of connectivity defects. TMA cations play a decisive role in the synthesis of the FER materials, and their presence allows the use of HMI to synthesize FER. Proton MAS NMR is used to quantify the accessibility of pyridine to acid sites in these FER samples, where it is found that the FER + HMI + TMA sample contains only 27% acid sites in the 8-MR channels, whereas FER + Pyr and FER + Pyr + TMA contain 89% and 84%, respectively. The constraint index (CI) test and the carbonylation of dimethyl ether (DME) with carbon monoxide are used as probe reactions to evaluate how changes in the aluminum distribution in these FER samples affect their catalytic behavior. Results show that the use of Pyr as an SDA results in the selective population of acid sites in the 8-MR channels, whereas the use of HMI generates FER zeolites with an increased concentration of acid sites in the 10-MR channels

    The 2016 seismic series in the south Alboran Sea: Seismotectonics, Coulomb Failure Stress changes and implications for the active tectonics in the area

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    The Southern Alboran Sea, particularly the area offshore Al Hoceima Bay, presents moderate but continuous seismic activity since the Mw 6.0 1994 Al Hoceima earthquake. The maximum magnitude occurred in the area was a Mw 6.3 earthquake in the 2004 Al Hoceima – Tamasint seismic series. Since then, the seismicity in the Al Hoceima area has been usual, with maximum seismic magnitudes around 4. An increase in the seismic rate was registered during 2015, especially from May, culminating in the seismic series in January 2016. The mainshock occurred on January 25th 2016 with a magnitude Mw 6.3 and it was preceded by a Mw 5.1 foreshock on January 21st. The seismic series took place at the western end of the Alboran Ridge. Towards the northeast the Alboran Ridge bends, and seems to be connected with the NW-SE right-lateral transtensional Yusuf Fault. The recorded seismicity is mainly located in the Alboran Ridge area and along the N-S Al-Idrisi Fault that seems to continue southwards, towards the Al Hoceima Bay. The focal mechanisms calculated previously in the area showed a leftlateral strike-slip faulting with some normal component in the Alboran Ridge; but always within a complex system of diffuse deformation and high rupture type variability. We have used 41 computed focal mechanisms of this seismic series to analyze its seismotectonics and structural characteristics. To group the focal mechanisms we used a clustering algorithm using the spatial distribution of the events and also the type of rupture mechanism. For each cluster we have obtained the composed focal mechanism, associating it to a particular fault or family of structures. We have tested the mechanical compatibility of these structures by Coulomb Failure Stress transfer modeling. The mainshock of the series occurred in the Al Idrisi Fault intersecting the western Alboran Ridge. This event triggered aftershocks and independent series in left-lateral strike-slip faults associated with the Al Idrisi Fault System towards the south, but also in near pure reverse faults in the fault zone bounding the the Alboran Ridge. Both types of faults and rupture-mechanisms coexist, linked mechanically by stress transfer, being coeval the uplift of the Alboran Ridge and its northwestward displacement due to the left-lateral motion of the Al-Idrisi Fault. It is also discussed how the contrasting faulting processes and seismic ruptures are developed in two differentially oriented fault zones in the context the current NW-SE plate convergence between the African and Eurasian plates in the Westernmost Mediterranean

    Genetic footprints of iberian cattle in America 500 years after the arrival of Columbus.

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    American Creole cattle presumably descend from animals imported from the Iberian Peninsula during the period of colonization and settlement, through different migration routes, andmay have also suffered the influence of cattle directly imported from Africa. The introduction of European cattle, which began in the 18th century, and later of Zebu from India, has threatened the survival of Creole populations, some of which have nearly disappeared or were admixed with exotic breeds. Assessment of the genetic status of Creole cattle is essential for the establishment of conservation programs of these historical resources. Methodology/Principal Findings: We sampled 27 Creole populations, 39 Iberian, 9 European and 6 Zebu breeds. We used microsatellite markers to assess the origins of Creole cattle, and to investigate the influence of different breeds on their genetic make-up. The major ancestral contributions are from breeds of southern Spain and Portugal, in agreement with the historical ports of departure of ships sailing towards the Western Hemisphere. This Iberian contribution to Creoles may also include some African influence, given the influential role that African cattle have had in the development of Iberian breeds, but the possibility of a direct influence on Creoles of African cattle imported to America can not be discarded. In addition to the Iberian influence, the admixture with other European breeds was minor. The Creoles from tropical areas, especially those from the Caribbean, show clear signs of admixture with Zebu. Conclusions/Significance: Nearly five centuries since cattle were first brought to the Americas, Creoles still show a strong and predominant signature of their Iberian ancestors. Creole breeds differ widely from each other, both in genetic structure and influences from other breeds. Efforts are needed to avoid their extinction or further genetic erosion, which would compromise centuries of selective adaptation to a wide range of environmental conditions

    A review of limitations and potentials of desalination as a sustainable source of water

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    This is the final version. Available on open access from Springer via the DOI in this recordData availability: All used data have been presented in the paper.For centuries, desalination, in one way or another, has helped alleviate water scarcity. Over time, desalination has gone through an evolutionary process influenced largely by available contemporary technology. This improvement, for the most part, was reflected in the energy efficiency and, in turn, in terms of the cost-effectiveness of this practice. Thanks to such advancements, by the 1960s, the desalination industry experienced notable exponential growth, becoming a formidable option to supplement conventional water resources with a reliable non-conventional resource. That said, often, there are pressing associated issues, most notably environmental, socioeconomic, health, and relatively recently, agronomic concerns. Such reservations raise the question of whether desalination is indeed a sustainable solution to current water supply problems. This is exceptionally important to understand in light of the looming water and food crises. This paper, thus, tends to review these potential issues from the sustainability perspective. It is concluded that the aforementioned issues are indeed major concerns, but they can be mitigated by actions that consider the local context. These may be either prophylactic, proactive measures that require careful planning to tailor the situation to best fit a given region or reactive measures such as incorporating pre- (e.g., removing particles, debris, microorganisms, suspended solids, and silt from the intake water prior to the desalination process) and post-treatments (e.g., reintroducing calcium and magnesium ions to water to enhance its quality for irrigation purposes) to target specific shortcomings of desalination
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