Magnetic Field Effects on the Transport Properties of One-sided Rough Wires

We present a detailed numerical analysis of the effect of a magnetic field on the transport properties of a `small-$N$' one-sided surface disordered wire. When time reversal symmetry is broken due to a magnetic field $B$, we find a strong increase with $B$ not only of the localization length $\xi$ but also of the mean free path $\ell$ caused by boundary states. Despite this, the universal relationship between $\ell$ and $\xi$ does hold. We also analyze the conductance distribution at the metal-insulator crossover, finding a very good agreement with Random Matrix Theory with two fluctuating channels within the Circular Orthogonal(Unitary) Ensemble in absence(presence) of $B$Comment: 5 pages, 4 figures, to appear in Phys. Rev.

Structural connectivity between the Páramos of Guacheneque and Los Cristales, Rabanal-Río Bogotá complex, Colombia

[EN] Structural connectivity is a measure of the spatio-temporal changes that affect the movement of species between elements of the landscape and availability of habitat; these modifications that have been documented for high mountain ecosystems in Colombia (páramo and high Andean forest) and are caused by agricultural and other economic activities that affect their integrity. The objective of this study was to evaluate the dynamics of the changes between plant cover (1987-2018) in the Guacheneque and Los Cristales páramos (Boyacá-Cundinamarca, Colombia). Images from Landsat 4 and 8 sensors were used. Pre and post-processing (supervised classification and field verification) were performed with ArcGIS and ERDAS. To estimate structural connectivity, metrics of landscape diversity, composition and configuration were calculated (Fragstats v4.2.1). Thematic reliability was 88%. Mosaic covering of pastures and crops (Mpc – 288 ha), dense grassland of firm ground (HdTf- 24 ha) and high open forest (Baa-165 ha), increased in 31 years, while dense bush (Ad) decreased 477 ha. The distance between tiles of Mpc and Ad increased (from 150.74 m to 170.70 m and from 196.96 m to 236.64 m respectively), and decreased for Baa (from 166.74 m to 159.27 m). Connectivity increased for Mpc and Baa, and decreased for Ad. The evaluated páramos make up a landscape with frequent and intensive land use, the effect of a long history of occupation of this territory. The dynamics of structural connectivity registered an increase in agricultural activities (páramo-grasslands transition). These have caused tensions and contradictions in the delimitation of páramos, a local loss of the natural area, a decrease in the average size of the tiles, and an increase in the perimeter /surface ratio distance between nuclei. The results corroborate the isolation and loss of habitat, the negative impacts on the biodiversity of the Rabanal-Río Bogotá páramos complex.[ES] La conectividad estructural es una medida del cambio espacio-temporal, que recae en el desplazamiento de las especies en el paisaje y la disponibilidad de hábitat; estas modificaciones se han documentado para ecosistemas de alta montaña en Colombia (páramo y bosque altoandino), causados por las actividades agrícolas y otras económicas que afectan su integridad. El objetivo de este estudio fue evaluar la dinámica del cambio, entre coberturas vegetales (1987-2018) en los páramos de Guacheneque y Los Cristales (Boyacá-Cundinamarca, Colombia). Se utilizaron imágenes de los sensores Landsat 4 y 8; se realizaron pre y pos-procesamientos (clasificación supervisada y verificación de campo) con ArcGIS y ERDAS. Para estimar la conectividad estructural se calcularon métricas de diversidad, composición y configuración del paisaje (Fragstats v4.2.1). La fiabilidad temática fue del 88%; las coberturas Mosaico de pastos y cultivos (Mpc), Herbazal denso de tierra firme (HdTf) y Bosque abierto alto (Baa), aumentaron en 31 años (288, 24 y 165 ha respectivamente), mientras, el Arbustal denso (Ad) disminuyó 477 ha. La distancia entre teselas de Mpc y Ad incrementó (de 150,74 a 170,70 m y de 196,96 a 236,64 m respectivamente), y disminuyó para Baa (de 166,74 a 159,27 m); la conectividad aumentó para el Mpc y Baa, y disminuyó para el Ad. Los páramos evaluados, conforman un paisaje con uso de suelo frecuente e intensivo, efecto de largas trayectorias de ocupación del territorio. La dinámica de conectividad estructural registró un aumento en las actividades agrícolas (transición páramo-pastizal); éstas han causado tensiones y contradicciones a la delimitación de páramos, pérdida local del área natural, disminución del tamaño medio de las teselas, distancia entre núcleos y aumento de la relación perímetro/superficie. Estos resultados corroboran el aislamiento y pérdida del hábitat, cuya incidencia negativa recae sobre la biodiversidad del complejo de páramos Rabanal-Río Bogotá.Forero-Gómez, YK.; Gil-Leguizamón, P.; Morales-Puentes, M. (2020). Conectividad estructural entre los Páramos de Guacheneque y Los Cristales, complejo Rabanal-río Bogotá, Colombia. Revista de Teledetección. 0(57):65-77. https://doi.org/10.4995/raet.2020.13946OJS657705

Three electron beams from a laser-plasma wakefield accelerator and the energy apportioning question

Laser-wakefield accelerators are compact devices capable of delivering ultra-short electron bunches with pC-level charge and MeV-GeV energy by exploiting the ultra-high electric fields arising from the interaction of intense laser pulses with plasma. We show experimentally and through numerical simulations that a high-energy electron beam is produced simultaneously with two stable lower-energy beams that are ejected in oblique and counter-propagating directions, typically carrying off 5-10% of the initial laser energy. A MeV, 10s nC oblique beam is ejected in a 30-60 degree hollow cone, which is filled with more energetic electrons determined by the injection dynamics. A nC-level, 100s keV backward-directed beam is mainly produced at the leading edge of the plasma column. We discuss the apportioning of absorbed laser energy amongst the three beams. Knowledge of the distribution of laser energy and electron beam charge, which determine the overall efficiency, is important for various applications of laser-wakefield accelerators, including the development of staged high-energy accelerators

Wide-angle electron beams from laser-wakefield accelerators

Advances in laser technology have driven the development of laser-wakefield accelerators, compact devices that are capable of accelerating electrons to GeV energies over centimetre distances by exploiting the strong electric field gradients arising from the interaction of intense laser pulses with an underdense plasma. A side-effect of this acceleration mechanism is the production of high-charge, low-energy electron beams at wide angles. Here we present an experimental and numerical study of the properties of these wide-angle electron beams, and show that they carry off a significant fraction of the energy transferred from the laser to the plasma. These high-charge, wide-angle beams can also cause damage to laser-wakefield accelerators based on capillaries, as well as become source of unwanted bremsstrahlung radiation

First-principles extrapolation method for accurate CO adsorption energies on metal surfaces

We show that a simple first-principles correction based on the difference between the singlet-triplet CO excitation energy values obtained by DFT and high-level quantum chemistry methods yields accurate CO adsorption properties on a variety of metal surfaces. We demonstrate a linear relationship between the CO adsorption energy and the CO singlet-triplet splitting, similar to the linear dependence of CO adsorption energy on the energy of the CO 2$\pi$* orbital found recently {[Kresse {\em et al.}, Physical Review B {\bf 68}, 073401 (2003)]}. Converged DFT calculations underestimate the CO singlet-triplet excitation energy $\Delta E_{\rm S-T}$, whereas coupled-cluster and CI calculations reproduce the experimental $\Delta E_{\rm S-T}$. The dependence of $E_{\rm chem}$ on $\Delta E_{\rm S-T}$ is used to extrapolate $E_{\rm chem}$ for the top, bridge and hollow sites for the (100) and (111) surfaces of Pt, Rh, Pd and Cu to the values that correspond to the coupled-cluster and CI $\Delta E_{\rm S-T}$ value. The correction reproduces experimental adsorption site preference for all cases and obtains $E_{\rm chem}$ in excellent agreement with experimental results.Comment: Table sent as table1.eps. 3 figure

Psychosocial burden in adult patients with atopic dermatitis

P16 Objective: Atopic dermatitis affects patients’ quality of life (QoL) in many ways. It is important to analyze the impact that the disease produces in order to better define the healthcare needs of adult patients with atopic dermatitis. Patients and Methods: 14 adult patients with atopic dermatitis were interviewed. The qualitative interviews were semi-structured and supported by a simple script, which allowed a complete and flexible interview. Results: Six affected areas of the patient’s life with atopic dermatitis were identified: economic, work-related, personal, psychosocial, clinical and relational. It is emphasized that atopic dermatitis has a great psychosocial impact on the adult patient, since it alters interpersonal relationships, generates rejection, stigmatization and social isolation, limits the patient in various areas and activities of their daily life or alters sleep, among others. The visible aspect, the itching-scratching cycle, the lack of awareness and ignorance of the disease, the lack of a definitive solution among the treatments and the side effects of some of them are of great concern. Conclusions: The QoL of the patients with atopic dermatitis is negatively affected and a holistic multidisciplinary intervention is necessary in order to mitigate the negative impact of the disease

Quality of life in hidradenitis suppurativa: psychometric properties of HSQOL-24

P14 Introduction: Hidradenitis Suppurativa (HS) has been associated with impaired quality of life (QoL). There are various measuring systems to assess physical severity; however, there are no specific QoL questionnaires for this disease in the Spanish language. Objective: To develop and validate a disease-specific instrument to measure QoL in patients with HS. Methods: A literature search was carried out to prepare a semi structured interview for patients with HS, as well as a Delphi expert consensus among health professionals. The validation with a sample of 130 patients is presented. The preliminary validation of the HSQoL-24 was passed twice to a group of 30 patients with 30 ± 10 days of interval. The DLQI and the Skindex-29 were used for its validation. Results: Cronbach alpha 0.87 indicates a good internal consistency of the questionnaire. The intraclass correlation coefficient (ICC) with the DLQI was 0.70 (p-value) (< 0.001), and 0.87 (p-value) (< 0.001) with the Skindex-29. Conclusions: The HSQoL-24 is the first specific self-administered questionnaire to assess QoL in patients with HS in Spanish. It is user friendly and easy to. This study demonstrates the excellent properties of the instrument: comprehensibility, reliability (test-retest), internal consistency, validity, comparison with DLQI and SKINDEX-29, and discriminative capacity

Células solares ultrafinas de Cu (In,Ga)Se2 : passivação de interfaces

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMO: A comunidade de Cu(In,Ga)Se2 (CIGS) tem focado grande parte da sua investigação no estudo e melhoramento das propriedades cristalinas do CIGS.A última estratégia utilizada, que tem permitido aumentar o valor de eficiência das células solares, passa pela implementação de elementos alcalinos através de tratamentos pós-deposição (PDT). Para se atingir valores de conversão de eficiência competitivos é necessário melhorar as interfaces do CIGS. Neste estudo, focamo-nos no estudo das propriedades morfológicas, estruturais e optoelectrónicas entre o CIGS e a alumina (Al2O3), que tem o potencial de ser usada como camada passivadora frontal. Pode-se concluir que as propriedades morfológicas e estruturais não são alteradas devido à deposição do Al2O3. O Al2O3 não resiste ao banho químico usado para a deposição do CdS. O Al2O3 apresenta um valor de densidade de defeitos baixos, uma propriedade desejada destas camadas. Este estudo demonstra a potencialidade de se utilizar a Al2O3, para camadas buffer alternativas, que não usem processos químicos durante a sua deposição.ABSTRACT: Cu(In,Ga)Se2 (CIGS) community have been focusing the research line in the study and improvement of the crystalline properties of CIGS. The last trend, to increase the light to power conversion efficiency values, is the use of fluoride-alkaline post-deposition treatments. (PDT). To reach competitive efficiency values, it is necessary to focus on the improvement of CIGS interface. In this work, we focus on the study of the structural, morphological and optoelectronic properties in the interface of CIGS and alumina (Al2O3) which has the potential to be used as front passivation layer. We can conclude that the structural and morphological properties of CIGS remain the same with the deposition of Al2O3. When it was deposited the CdS, on Al2O3, the Al2O3 layer does not resist to the CdS chemical bath deposition. The interface Al2O3/CIGS has a low density of defects value, which is one of the desired properties of a passivation layer. This study demonstrates the potential of using Al2O3 as a front passivation layer with alternative buffer layers to CdS that do not use chemical processes during the deposition.info:eu-repo/semantics/publishedVersio

Melanesian and Asian origins of Polynesians: mtDNA and Y chromosome gradients across the Pacific

The human settlement of the Pacific Islands represents one of the most recent major migration events of mankind. Polynesians originated in Asia according to linguistic evidence or in Melanesia according to archaeological evidence. To shed light on the genetic origins of Polynesians, we investigated over 400 Polynesians from 8 island groups, in comparison with over 900 individuals from potential parental populations of Melanesia, Southeast and East Asia, and Australia, by means of Y chromosome (NRY) and mitochondrial DNA (mtDNA) markers. Overall, we classified 94.1% of Polynesian Y chromosomes and 99.8% of Polynesian mtDNAs as of either Melanesian (NRY-DNA: 65.8%, mtDNA: 6%) or Asian (NRY-DNA: 28.3%, mtDNA: 93.8%) origin, suggesting a dual genetic origin of Polynesians in agreement with the "Slow Boat" hypothesis. Our data suggest a pronounced admixture bias in Polynesians toward more Melanesian men than women, perhaps as a result of matrilocal residence in the ancestral Polynesian society. Although dating methods are consistent with somewhat similar entries of NRY/mtDNA haplogroups into Polynesia, haplotype sharing suggests an earlier appearance of Melanesian haplogroups than those from Asia. Surprisingly, we identified gradients in the frequency distribution of some NRY/mtDNA haplogroups across Polynesia and a gradual west-to-east decrease of overall NRY/mtDNA diversity, not only providing evidence for a west-to-east direction of Polynesian settlements but also suggesting that Pacific voyaging was regular rather than haphazard. We also demonstrate that Fiji played a pivotal role in the history of Polynesia: humans probably first migrated to Fiji, and subsequent settlement of Polynesia probably came from Fiji

Patient reported outcomes (PROS) in psoriasis patients

P20 Introduction: Psoriasis is a chronic skin disease with negative physical, mental and social manifestations. Method: We carried out a longitudinal and prospective study under routine clinical practice conditions. The objective of the study was to measure quality of life with the Short Form-36 Survey (SF-36) and correlate the results with clinical variables using the PASI and BSA in a group of 17 patients with moderate to severe psoriasis treated with Ustekinumab. Results: In the baseline evaluation we observed the following results: 35.3% reported physical malfunction, 64.7% debilitating pain, 82.3% poor health in general, 76.4% bad vitality, 88.2% social malfunction, 100% emotional malfunction and 82.3% poor mental health. At week 78 we observed the following results: 41.15% reported very good physical functioning, 76.1% no pain, 58.8% good general health, 58.8% very good vitality, 70%, 5% good social functioning, 70.5% good emotional functioning and 52.9% good mental health. Conclusion: We observed that the perception of patients with moderate-severe psoriasis regarding their health at the beginning of treatment with Ustekinumab was poor and that they experienced a significant improvement throughout the successive weeks of treatment