Thermal entanglement witness for materials with variable local spin lengths

We show that the thermal entanglement in a spin system using only magnetic susceptibility measurements is restricted to the insulator materials. We develop a generalization of the thermal entanglement witness that allows us to get information about the system entanglement with variable local spin lengths that can be used experimentally in conductor or insulator materials. As an application, we study thermal entanglement for the half-filled Hubbard model for linear, square and cubic clusters. We note that it is the itinerancy of electrons that favors the entanglement. Our results suggest a weak dependence between entanglement and external spin freedom degrees.Comment: 4 pages, 3 figure

Associação de heparina e antiveneno: eficácia da neutralização dos venenos de Bothrops atrox e Bothrops erythromelas

Heparin, in some regions of Brazil has been used in the treatment of bothropic accidents, but the data found in the literature are inconclusive about its effectiveness. The venoms of Bothrops atrox and of B. erythromelas were characterized according to their biological activities. The capacity of heparin in neutralizing these activities was tested with doses of 3 and 6 IU in isolated form and associated to Antibothropic Serum (ABS). It was verified that heparin, in doses of 3 and 6 IU, was not effective in neutralizing the desfibrinating and edema-forming activities of B. atrox venom and the hemorrhagic and coagulant actions of both venoms. Heparin diminished the effectiveness of the ABS in the neutralization of the hemorrhagic and edema-forming activities of the B. atrox venom. However, heparin in the 6 IU dose was capable of neutralize the edema-forming of the B. erythromelas and increase the effectiveness of the ABS. Heparin also neutralized the phospholipasic A2 activity of B. atrox (14.3%) and B. erythromelas (28.0%) venoms. For B. erythromelas venom, the associated treatment, heparin and ABS, was more effective in the neutralization of its lethal activity.A heparina tem sido utilizada no tratamento dos acidentes botrópicos em algumas regiões do Brasil, porém, os dados encontrados na literatura são inconclusivos sobre sua eficácia. Os venenos de Bothrops atrox e de B. erythromelas foram caracterizados segundo suas atividades biológicas. A capacidade da heparina em neutralizar estas atividades foi testada com as doses de 3 e 6UI de forma isolada e associada ao soro Antibotrópico (SAB). Verificou-se que a heparina nas doses de 3 e 6UI, não foi eficaz em neutralizar a atividade desfibrinante e edematogênica do veneno de B. atrox e as ações hemorrágica e coagulante dos dois venenos. A heparina diminuiu a eficácia do soro SAB na neutralização das atividades hemorrágica e edematogênica do veneno de B. atrox. Contudo, a heparina na dose de 6UI foi capaz de neutralizar a atividade edematogênica do veneno de B. erythromelas e aumentar a eficácia do soro SAB. A heparina neutralizou ainda a atividade fosfolipásica A2 dos venenos de B. atrox (14,3%) e de B. erythromelas (28,0%). Para o veneno de B. erythromelas, o tratamento associado de heparina e soro SAB, foi mais eficaz na neutralização da atividade letal

The influence of the pedagogical model on psychological variables in 1st year students from ESTSP-IPP

Introdução – A adaptação ao ensino superior reveste-se de experiências académicas que podem constituir fonte de stress para os estudantes. A implementação de novos modelos pedagógicos, no âmbito do processo de Bolonha, introduz novas variáveis cujo impacto, designadamente em termos de saúde, importa conhecer. Este estudo tem como objetivo analisar as associações entre modelo pedagógico (Problem Based Learning – PBL vs. modelos próximos do tradicional) e variáveis psicológicas (coping, desregulação emocional, sintomas psicossomáticos, perceção de stress e afeto). Metodologia – O estudo tem um design transversal. Foram usados os seguintes questionários online: Brief-COPE, Escala de Dificuldades de Regulação Emocional, Questionário de Manifestações Físicas de Mal-Estar, Escala de Stress Percebido e Escala de Afeto Positivo e Negativo. A amostra é constituída por 183 estudantes do primeiro ano (84% do género feminino) de cursos da Escola Superior de Tecnologia da Saúde do Porto – Instituto Politécnico do Porto (ESTSP-IPP). Resultados – Foram encontradas correlações significativas entre as variáveis demográficas e psicológicas. Considerando diferentes modelos pedagógicos, foram encontradas diferenças significativas nas variáveis psicológicas. Os principais preditores de stress na amostra foram: ser mulher, frequentar uma licenciatura no modelo PBL, ter maiores índices de desregulação emocional, apresentar mais sintomas psicossomáticos, menos afeto positivo e mais afeto negativo. Conclusão – As diferenças encontradas entre modelos pedagógicos são discutidas, possibilitando a reflexão sobre as implicações práticas e sugestões para futuras investigações.Introduction – Adapting to Higher Education is filled with academic experiences that might be stressful for students. The new pedagogical models brought about by the Bologna process put into play new variables that are important to look at, namely in terms of health. This research aims to analyze associations between the pedagogical model (Problem Based Learning vs more traditional approaches) and psychological variables (coping, emotional deregulations, psychosomatic symptoms, perceived stress and affect). Method – This study has a cross-sectional design. The following online questionnaires were used: Brief-COPE, Difficulties in Emotion Regulation Scale, Perceived Stress Scale, Manifestations of Physical Discomfort Questionnaire, and Positive and Negative Affect Schedule. The sample consisted in 183 first-year students (84% female) from School of Allied Health Sciences – Polytechnic Institute of Porto. Results – Significant correlations between demographic and psychological variables were found. Considering different pedagogical models, significant differences in psychological variables were found. The main predictors of stress in the sample were: being female, inclusion in the PBL model, higher indexes of emotional deregulation, more psychosomatic symptoms, lower positive affect and higher negative affect. Conclusion – Differences between pedagogical models are discussed, while reflecting on practical implications and suggestions for future research

Recent Progress in Stimuli-Responsive Antimicrobial Electrospun Nanofibers

Electrospun nanofibrous membranes have garnered significant attention in antimicrobial applications, owing to their intricate three-dimensional network that confers an interconnected porous structure, high specific surface area, and tunable physicochemical properties, as well as their notable capacity for loading and sustained release of antimicrobial agents. Tailoring polymer or hybrid-based nanofibrous membranes with stimuli-responsive characteristics further enhances their versatility, enabling them to exhibit broad-spectrum or specific activity against diverse microorganisms. In this review, we elucidate the pivotal advancements achieved in the realm of stimuli-responsive antimicrobial electrospun nanofibers operating by light, temperature, pH, humidity, and electric field, among others. We provide a concise introduction to the strategies employed to design smart electrospun nanofibers with antimicrobial properties. The core section of our review spotlights recent progress in electrospun nanofiber-based systems triggered by single- and multi-stimuli. Within each stimulus category, we explore recent examples of nanofibers based on different polymers and antimicrobial agents. Finally, we delve into the constraints and future directions of stimuli-responsive nanofibrous materials, paving the way for their wider application spectrum and catalyzing progress toward industrial utilization

Preliminary petrological inferences on the high-grade metamorphic rocks exhumed by the South Rif Thrust, Prerif, Northern Morocco

The exhumation of deep crustal rocks along major shear zones is common, yet a highly debated subject, particularly when occurring during recent tectonic events. This is the case of the South Rif Thrust (SRT), a significant shear zone analogous to those described at the Betic Cordillera in Spain. The SRT separates two major geodynamic domains in Northern Morocco: a) the Prerif, to the North, mostly composed of Miocenic sedimentary units on top of a stratigraphic sequence continuously deposited since the Triassic; and b) the Western Meseta, to the South, mostly composed of Paleozoic metasedimentary units, correlated with the Iberian Variscan Belt [1]. Associated to the SRT, and exhumed by its activity, there is a dismembered and exotic high-grade metamorphic belt representative of the middle and lower crust. Also in this region, several thermo-mineral waters occur, whose deep circulation can be traced back to the SRT [2]. Detailed geological mapping, structural, stratigraphic and petrographic analyses on this dismembered and highly deformed exotic sequence reveal the presence of low- to high-grade metasediments (including migmatites and felsic granulites), but mostly high-grade metabasic and basic rocks, including amphibolites, mafic granulites and gabbros. Preliminary geothermobarometry in the mafic granulites provides an important characterization of the infra-crustal conditions of the pre-Alpine geodynamics and of the activity and exhumation along the SRT since the Miocene: a) the mafic granulites endured M1 metamorphic peak conditions of T = 1030 ºC at P = 8.5 kbar, which is consistent with typical conductive continental crust geothermal gradients (~30 ºC.km-1); b) M2 retrogression occurred by near isothermal decompression at T = 820 ºC and P = 3.5 kbar, implying an initial vertical uplift of >18 km of the granulite-facies rocks to very shallow levels; c) during this period, the geothermal gradient in the region surpassed 60 ºC.km-1; d) exhumation and retrogression continued by almost isobaric cooling at T < 750 ºC and P = 1.7 – 3.0 kbar with an M3 amphibolitization of the granulites after late water inflow. The overall metamorphic evolution of these deep crustal rocks is compatible with a clockwise P-T path, involving initial fast tectonic exhumation, followed by thermal readjustment to shallower levels. This is consistent with the currently observed geothermal gradients in the area (≤ 42 ºC.km-1) [2] which may still be a reflection of the events during the Miocene. These petrological constrains on the tectonic processes associated with the exhumation of this lower crust segment and the activity of the SRT during the closure of the Alboran Basin are key to understanding the circulation of deep hot waters, which are an important part of the economy of this region in Northern Morocco.publishe

Computer code for double beta decay QRPA based calculations

The computer code developed by our group some years ago for the evaluation of nuclear matrix elements, within the QRPA and PQRPA nuclear structure models, involved in neutrino-nucleus reactions, muon capture and β± processes, is extended to include also the nuclear double beta decay.Publicado en AIP Conference Proceedings, vol. 1625Facultad de Ciencias ExactasInstituto de Física La Plat

Decapod crustacean larval communities in the Balearic Sea (western Mediterranean): Seasonal composition, horizontal and vertical distribution patterns

Decapod crustaceans are the main target species of deepwater bottomtrawl fisheries in the Balearic Sea but little is known about their larval stages. This work focuses on the species composition of the decapod larval community, describing the main spatio-temporal assemblages and assessing their vertical distribution. Mesozooplankton sampling was carried out using depth-stratified sampling devices at two stations located over the shelf break and themid slope, in the north-western and southern Mallorca in late autumn 2009 and summer 2010. Differences among decapod larvae communities, in terms of composition, adult's habitat such as pelagic or benthic, and distribution patternswere observed between seasons, areas and station. Results showed that for both seasonsmost species and developmental stages aggregatedwithin the upperwater column (above 75 mdepth) and showed higher biodiversity in summer compared to late autumn. Most abundant species were pelagic prawns (e.g., Sergestidae) occurring in both seasons and areas. The larval assemblages' distributions were different between seasonal hydrographic scenarios and during situations of stratified and non-stratified water column. The vertical distribution patterns of different larval developmental stages in respect to the adult's habitat were analyzed in relation to environmental variables. Fluorescence had the highest explanatory power. Four clearly different vertical patterns were identified: two corresponding to late autumn, which were common for all the main larval groups and other two in summer, one corresponding to larvae of coastal benthic and the second to pelagic species larvae.Versión del editor2,655

Regulation of histone H2A.Z expression is mediated by sirtuin 1 in prostate cancer

Histone variants seem to play a major role in gene expression regulation. In prostate cancer, H2A.Z and its acetylated form are implicated in oncogenes’ upregulation. SIRT1, which may act either as tumor suppressor or oncogene, reduces H2A.Z levels in cardiomyocytes, via proteasome-mediated degradation, and this mechanism might be impaired in prostate cancer cells due to sirtuin 1 downregulation. Thus, we aimed to characterize the mechanisms underlying H2A.Z and SIRT1 deregulation in prostate carcinogenesis and how they interact. We found that H2AFZ and SIRT1 were up- and downregulated, respectively, at transcript level in primary prostate cancer and high-grade prostatic intraepithelial neoplasia compared to normal prostatic tissues. Induced SIRT1 overexpression in prostate cancer cell lines resulted in almost complete absence of H2A.Z. Inhibition of mTOR had a modest effect on H2A.Z levels, but proteasome inhibition prevented the marked reduction of H2A.Z due to sirtuin 1 overexpression. Prostate cancer cells exposed to epigenetic modifying drugs trichostatin A, alone or combined with 5-aza-2’-deoxycytidine, increased H2AFZ transcript, although with a concomitant decrease in protein levels. Conversely, SIRT1 transcript and protein levels increased after exposure. ChIP revealed an increase of activation marks within the TSS region for both genes. Remarkably, inhibition of sirtuin 1 with nicotinamide, increased H2A.Z levels, whereas activation of sirtuin 1 by resveratrol led to an abrupt decrease in H2A.Z. Finally, protein-ligation assay showed that exposure to epigenetic modifying drugs fostered the interaction between sirtuin 1 and H2A.Z. We concluded that sirtuin 1 and H2A.Z deregulation in prostate cancer are reciprocally related. Epigenetic mechanisms, mostly histone post-translational modifications, are likely involved and impair sirtuin 1-mediated downregulation of H2A.Z via proteasome-mediated degradation. Epigenetic modifying drugs in conjunction with enzymatic modulators are able to restore the normal functions of sirtuin 1 and might constitute relevant tools for targeted therapy of prostate cancer patient