502 research outputs found
Extracting Double Diode Model Parameters Based on Cross Entropy Optimization Algorithm
A Cross Entropy (CE) optimization technique is suggested in this study in order to extract the optimal parameters of solar cell model. The solar cell model namely Double diode model, is used in this paper in the purpose to verify the proposed method. The seven unknown parameters of double diode model are: the photo-generated current, the diffusion current, saturation current, the series resistance, the shunt resistance, the diffusion ideality factor and recombination diode ideality factor. These parameters were used to determine the corresponding maximum power point (MPP) from the illuminated current–voltage (I–V) characteristic. The metaheuristic algorithms have created a center of attention due to the non-linearity of the solar cell models and the incapability of traditional optimization methods to precisely extract the parameters. Different cases and studies have been done to identify the unknown parameters of the solar cell double model. The efficiency of CE algorithm is investigated by comparing this method with various and different other techniques. This comparison is done using statistical indicators and analysis such as: mean absolute bias error, root mean square error and coefficient of determination. The results show that CE is a very efficient technique to identify the electrical parameters of the PV solar cells and modules
Physiological mechanisms and adaptation strategies of Lactuca sativa L. in response to Olea europaea L. and Ficus carica L. allelochemicals
Agro-industrial wastes of Ficus carica L. and Olea europaea L. represent great sources of bioactive phenolic compounds that would be actively involved in sustainable development. Most of these wastes possess a valuable source of phytotoxic compounds that would be used as potential bioherbicides, but their function and mechanisms of action in cultivated crops remain far to be understood. In this study, we investigate the biochemical and physiological mechanisms of action of fig and olive allelochemicals extracts in lettuce as a model plant for weed species studies. Results revealed that these allelochemicals triggered an oxidative stress through cell membrane damage in lettuce roots and leaves, which was mitigated by various adaptive responses. Therefore, an intricate defense system was implicated by the increase of enzymatic and non-enzymatic antioxidants in lettuce tissues. This adaptive physiological response was highly correlated with the regulation of the phenylpropanoid pathway through the distinguished activation of phenylalanine ammonia-lyase by 98% and phenolic accumulation by 85% under olive and fig leaves aqueous extracts. The outcomes of this study will help understanding the response of cultivated crop to fig and olive phenolic compounds that can be selective in their actions, or the plants can be selective in their responses
Fascitis necrotizante de extremidad superior: a propósito de un caso
Los autores presentan un caso de fascitis necrotizante en miembro superior
causada por la combinación de bacterias estreptococo microaerofílico y estafilococo
aureus. El paciente ha sobrevivido con una pérdida orgánica mínima (amputación
del quinto dedo) y una recuperación funcional completa. Se destaca el papel de la antibioterapia
precoz.The authors report a case of necrotizing fascitis of the upper limb, produced
by a microaerophilic streptococcus and staphilococcus aureus. The only organic
sequelae for the patient was amputation of the little finger with a complete recovery of
the functional capacity. The role of the early institution of high dose antibiotic therapy
is emphasized
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Reclaiming the witch: Processes and heroic outcomes of consumer mythopoesis
Although previous research has investigated consumer mythopoesis (consumers’ identity work using marketplace myths), little is known about its enactment involving ambiguous myths. Here, we investigate the myth of the witch (predominantly depicted by dominant mythmakers as a villain but recently repositioned more positively) and describe how consumers reclaim the empowering and heroic aspects of the ambiguous witch myth. Based on a qualitative study using archival data and in-depth interviews with self-proclaimed witches, we argue that the witch’s ambiguity originates in different mythopoetic cycles. Then, we describe the following processes through which consumers reclaim positive cycles: incarnating the myth, coming out to selected others and practising myth-related craft. Finally, we show that reclaiming results in new forms of heroic agency that amplify the myth’s ambiguity and identity value. Our results reveal that consumers cope with market-wide paradoxical injunctions, stressful situations and marginalisation by transforming these pressures into acts of self-heroism
Production of Sodium Bose--Einstein condensates in an optical dimple trap
We report on the realization of a sodium Bose--Einstein condensate (BEC) in a
combined red-detuned optical dipole trap, formed by two beams crossing in a
horizontal plane and a third, tightly focused dimple trap propagating
vertically. We produce a BEC in three main steps: loading of the crossed dipole
trap from laser-cooled atoms, an intermediate evaporative cooling stage which
results in efficient loading of the auxiliary dimple trap, and a final
evaporative cooling stage in the dimple trap. Our protocol is implemented in a
compact setup and allows us to reach quantum degeneracy even with relatively
modest initial atom numbers and available laser power
Systemic restoration of UBA1 ameliorates disease in spinal muscular atrophy
Acknowledgments Blood biochemistry analysis and serum analysis were performed by the Easter Bush Pathology Department, University of Edinburgh. Animal husbandry was performed by Centre for Integrative Physiology bio-research restructure technical staff, University of Edinburgh. Assistance with intravenous injections was provided by Ian Coldicott (University of Sheffield) and Hannah Shorrock (University of Edinburgh). Human blood cDNA was a gift to GH from Kathy Evans, University of Edinburgh. Imaging was performed at the IMPACT imaging facility, University of Edinburgh, with technical assistance from Anisha Kubasik-Thayil. The authors would also like to thank Lyndsay Murray for technical discussions relating to qRT-PCR analysis. This work was supported by funding from the SMA Trust and the Anatomical Society (via grants to THG); the Euan MacDonald Centre for Motor Neurone Disease Research (via grants to THG and SHP); the Wellcome Trust (via grants to EJNG and THG); Muscular Dystrophy UK (via grants to THG and CGB); a Elphinstone Scholarship from the University of Aberdeen (to SHP); and The French Muscular Dystrophy Association (via grants to CM and JC).Peer reviewedPublisher PD
Economic efficiency of public secondary education expenditure: how different are developed and developing countries?
Este estudio mide la eficiencia del gasto público en educación secundaria en 35 países desarrollados y en desarrollo mediante el uso de una metodología semiparamétrica DEA (análisis envolvente de datos) en dos pasos. En primer lugar, implementamos dos modelos de frontera transfronteriza para el período 2009-2012: uno que utiliza un aporte físico (es decir, relación maestro-alumno) y otro que utiliza un aporte monetario (es decir, gasto gubernamental por estudiante secundario). Estos resultados se corrigen por los efectos del PIB per cápita y el logro educativo de los adultos como insumos no discrecionales. Obtenemos cuatro resultados importantes: (i) los países desarrollados y en desarrollo tienen los mismos procesos de producción educativa cuando se comparan utilizando insumos físicos, pero no cuando se los compara con insumos monetarios; (ii) los países en desarrollo podrían aumentar sus tasas de matrícula y puntajes PISA en aproximadamente un 9% y un 5%, respectivamente, al mantener las mismas proporciones maestro-alumno y los niveles de gasto público que los países desarrollados; (iii) Irlanda, Japón y Corea son países eficientes en los dos modelos de frontera (Colombia también se incluye en esta categoría cuando se utiliza la relación maestro-alumno como insumo); y (iv) la sólida evidencia empírica indica que tanto el ingreso como el logro educativo de los padres afectan positivamente la eficiencia de la educación pública en ambos modelos.This study measures the efficiency of public secondary education expenditure in 35 developing and developed countries using a two-step semi-parametric DEA (data envelopment analysis) methodology. First, we implement two cross-country frontier models for the 2009-2012 period: one using a physical input (i.e., teacher-pupil ratio) and one using a monetary input (i.e., government expenditure per secondary student). These results are corrected by the effects of GDP per capita and adult educational attainment as non-discretionary inputs. We obtain four important results: (i) developed and developing countries have the same education production processes when they are compared using physical inputs but not when compared using monetary inputs; (ii) developing countries could increase their enrollment rates and PISA scores by approximately 9% and 5%, respectively, by maintaining the same teacher-pupil ratios and public spending levels as developed countries; (iii) Ireland, Japan and Korea are efficient countries in the two frontier models (Colombia is also included in this category when the teacher-pupil ratio is used as input); and (iv) robust empirical evidence indicates that both income and parental educational attainment positively affect the efficiency of public education in both models
Fractura triplana epifisaria distal de tibia: a propósito de un caso con interposición de periostio
Se presenta un caso de fractura triplana en 2 fragmentos en un paciente varón
de 13 años tratado quirúrgicamente, observando la interposición perióstica en el plano axial a
nivel del fragmento antero-externo, que impedía la reducción anatómica de la zona epifisaria
articular. Se analiza la anatomía quirúrgica de las fracturas triplanas considerando que esta lesión
puede ser más frecuente de lo que se ha informado, y sólo valorada en los casos en que se
emplee un abordaje antero-externo.The case of a 13-year-old boy with a two-fragment triplane fracture of the distal
epiphysis of the tibia is presented. At surgery, an interposition of the periosteum in the axial
plane behind the antero-lateral fragment, preventing the anatomical reduction of the epiphyseal
joint surface was found. The surgical anatomy of triplane fractures is review taking into account
that this lesion can be more frequent that it has been reported. The true incidence
should be evaluated at surgery by antero-lateral approach
The linear ubiquitin chain assembly complex regulates TRAIL-induced gene activation and cell death.
The linear ubiquitin chain assembly complex (LUBAC) is the only known E3 ubiquitin ligase which catalyses the generation of linear ubiquitin linkages de novo LUBAC is a crucial component of various immune receptor signalling pathways. Here, we show that LUBAC forms part of the TRAIL-R-associated complex I as well as of the cytoplasmic TRAIL-induced complex II In both of these complexes, HOIP limits caspase-8 activity and, consequently, apoptosis whilst being itself cleaved in a caspase-8-dependent manner. Yet, by limiting the formation of a RIPK1/RIPK3/MLKL-containing complex, LUBAC also restricts TRAIL-induced necroptosis. We identify RIPK1 and caspase-8 as linearly ubiquitinated targets of LUBAC following TRAIL stimulation. Contrary to its role in preventing TRAIL-induced RIPK1-independent apoptosis, HOIP presence, but not its activity, is required for preventing necroptosis. By promoting recruitment of the IKK complex to complex I, LUBAC also promotes TRAIL-induced activation of NF-κB and, consequently, the production of cytokines, downstream of FADD, caspase-8 and cIAP1/2. Hence, LUBAC controls the TRAIL signalling outcome from complex I and II, two platforms which both trigger cell death and gene activation
Room-temperature magnetoelectric effect in lead-free multiferroic BaCaTiSnO-CoFeO particulate composites
Multiferroic particulate composites
BaCaTiSnO-CoFeO with (
= 0.1, 0.2, 0.3, 0.4 and 0.5) have been prepared by mechanical mixing of the
calcined and milled individual ferroic phases. X-ray diffraction and Raman
spectroscopy analysis confirmed the formation of both perovskite
BaCaTiSnO (BCTSn) and spinel
CoFeO (CFO) phases without the presence of additional phases. The
morphological properties of the composites were provided by using Field
Emission Scanning Electron Microscopy. The BCTSn-CFO composites exhibit
multiferroic behavior at room temperature, as evidenced by ferroelectric and
ferromagnetic hysteresis loops. The magnetoelectric (ME) coupling was measured
under a magnetic field up to 10 kOe and the maximum ME response found to be 0.1
mV /cm/ Oe for the composition 0.7 BCTSn-0.3 CFO exhibiting a high degree of
pseudo-cubicity and large density
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