Phase diagram of two interacting helical states

We consider two coupled time-reversal-invariant helical edge modes of the same helicity, such as would occur on two stacked quantum spin Hall insulators. In the presence of interaction, the low-energy physics is described by two collective modes, one corresponding to the total current flowing around the edge and the other one describing relative fluctuations between the two edges.We find that quite generically, the relative mode becomes gapped at low temperatures, but only when tunneling between the two helical modes is nonzero. There are two distinct possibilities for the gapped state depending on the relative size of different interactions. If the intraedge interaction is stronger than the interedge interaction, the state is characterized as a spin-nematic phase. However, in the opposite limit, when the interaction between the helical edge modes is strong compared to the interaction within each mode, a spin-density wave forms, with emergent topological properties. First, the gap protects the conducting phase against localization by weak nonmagnetic impurities; second, the protected phase hosts localized zero modes on the ends of the edge that may be created by sufficiently strong nonmagnetic impurities

Reconstruction of late Quaternary marine and terrestrial environmental conditions of Northwest Africa and Southeast Australia A multiple organic proxy study using marine sediments

NW Africa and SE Australia are regions which are particularly vulnerable to climate change. In this thesis, organic proxies are used from marine sediment cores to reconstruct past environmental conditions from these areas. In sediments from NW Africa, the UK'37 showed an efficient proxy for sea surface temperature (SST) reconstruction, while the TEXH86 reconstructed thermocline temperatures. The UK'37 and TEXH86 records for the last 192 ka showed that periods of reduced AMOC coincide with a reduction in the vertical temperature gradient. Thus, variations in AMOC strength is a driver of the thermocline structure in the tropical Atlantic. Three independent organic proxies (UK’37,TEXH86 and LDI) were used to reconstruct SSTs for the last 135 ka in sediments from offshore SE Australia. Comparison with SST estimates based on foraminiferal assemblages shows that LDI temperatures compared well with the temperature of the warmest month, TEXH86 with the temperature of the coolest month and UK’37 with mean annual temperature. Thus, the application of these 3 proxies together at this area enables the reconstruction of SST variations from different seasons. Accumulation rates and concentrations of biomarkers from marine plankton classes were used to examine the changes in productivity at the above mentioned sites during the late Quaternary. In NW Africa, a positive correlation was observed between TOC content, productivity proxies (for dinoflagellates, eustigmatophytes, haptophytes) and the sedimentary Fe, in particular during periods of high aridity on the continent. Thus, the productivity in this area is considerably influenced by the fertilization effect of the Sahara dust, while in SE Australia, Proboscia diatom productivity seems to be controlled by the transport of silicic acid to this area as increases in its productivity matched increased diatom productivity observed at some sites of the tropical equatorial Pacific. To assess changes in the vegetation of NW Africa and SE Australia, the d13C of the n-alkanes from plant leaf waxes were analysed. Sediments from the NW Africa reveal three periods (early Holocene, 50–45 and 120–110 ka) during the past 192 ka when the central Sahara/Sahel contained a higher percentage of C3 plants, indicating wetter conditions than at present. A remarkably close correlation between d13C of benthic foraminifera and n-alkanes indicates a connection between variability in AMOC strength and vegetation type in the Sahara/Sahel region. The n-alkane d13C record from SE Australia reveals an extensive period (68-31ka) of high C4 plant abundance that is punctuated by a sharp increase in C3 vegetation at ~43 ka. This sharp increase in C3 vegetation lasts ~5 ka and is characterized by increased levels of biomass burning. Thus, this vegetation change was likely caused by increased burning events and/or by reduced herbivory as it follows the main period of the late Quaternary megafauna extinction in Australia. This thesis demonstrates the benefit of applying multiple organic proxies on marine sediments to assess marine and terrestrial paleoenvironmental changes and it has thereby provided new insights in the cause and effect of environmental changes in marine and continental areas of NW Africa and SE Australia

Projetos De Modernidade: Autoritarismo, Eugenia E Racismo No Brasil Do Século Xx

This article takes as its starting point the idea of modernity in Brazil and its deployment in Brazilian society by means of an authoritarian project that values the “whitening” of the country. In this sense, we will discuss, albeit briefly, the concept of modernity. To explain the phenomenon of modernity through authoritarianism, we will focus on the concept of authoritarian nationalism. The racial issue is the focal point of the discussion, so we will present a synthesis of Brazilian social thought from the mid-19th century to the 1930s, in order to deal with the idea of eugenics in Brazil and the reception of European racist theories in that country. © 2016, Universidad de los Andes, Bogota Colombia. All rights reserved.201658283

Annotated Checklist Of Echinoderms From Araçá Bay, Southeastern Brazil

We present a species list of echinoderms from Araçá Bay, state of São Paulo. Altogether, 863 specimens belonging to 25 species, 19 genera, and 13 families were exhaustively collected during three years in consolidated and non-consolidated substrate. Ophiuroidea was the most representative taxon with 16 species, follow by Asteroidea with four species, Echinoidea with three, and Holothuroidea with two species. The brittle stars Amphiura kinbergi and Ophiothela cf. mirabilis are new records for Araçá Bay. We confirm that Araçá Bay is one of the best known area of echinoderm diversity in Brazil considering that the perimeter (3 km) of the bay corresponds to only 0.03% of the Brazilian coastline (8500 km). This work complements the knowledge of Araçá Bay biodiversity and supports future interventions, management and maintaining the diversity of this wonderful group of marine animals. © 2016 Check List and Authors.12

Peat properties, dominant vegetation type and microbial community structure in a tropical peatland

Tropical peatlands are an important carbon store and source of greenhouse gases, but the microbial component, particularly community structure, remains poorly understood. While microbial communities vary between tropical peatland land uses, and with biogeochemical gradients, it is unclear if their structure varies at smaller spatial scales as has been established for a variety of peat properties. We assessed the abundances of PLFAs and GDGTs, two membrane spanning lipid biomarkers in bacteria and fungi, and bacteria and archaea, respectively, to characterise peat microbial communities under two dominant and contrasting plant species, Campnosperma panamensis (a broadleaved evergreen tree), and Raphia taedigera (a canopy palm), in a Panamanian tropical peatland. The plant communities supported similar microbial communities dominated by Gram negative bacteria (38.9–39.8%), with smaller but significant fungal and archaeal communities. The abundance of specific microbial groups, as well as the ratio of caldarchaeol:crenarchaeol, isoGDGT: brGDGTs and fungi:bacteria were linearly related to gravimetric moisture content, redox potential, pH and organic matter content indicating their role in regulating microbial community structure. These results suggest that tropical peatlands can exhibit significant variability in microbial community abundance even at small spatial scales, driven by both peat botanical origin and localised differences in specific peat properties

Nucleation kinetics of crystalline phases from a kaolinitic body used in the processing of red ceramics

The crystallization kinetics of red ceramic raw material from the western part of São Paulo State, Brazil, was examined by differential thermal analysis (DTA) and X-ray diffraction (XRD). The chemical composition of the clay sample was determined by X-ray fluorescence (XRF). Non-isothermal crystallization kinetic methods have been applied to the study of the mechanism of crystallization in this kaolinitic material. The exothermic peak shifted to higher temperatures (945 to 974 °C) with increasing heating rate (10 to 50 °C/min). The average activation energies determined by the Kissinger method (787 ± 85 kJ/mol) and the Ligero method (721 ± 32 kJ/mol) are in agreement. The Avrami constant n obtained by the Ligero method and the m parameter (Matusita method) values were between 1 and 1.5, which indicate a three-dimensional crystal growth with polyhedral morphology and surface nucleation as the dominant mechanism. X-ray diffraction data indicate that this activation energy is not associated with the crystallization of mullite. Scanning electron microscopy (SEM) images of fired (1000 and 1190 °C) samples show their densification during the sinterization process.The authors thank FUNDUNESP and FAPESP (2008/04368-4) for financial support of this work. We also are grateful to PROPE/UNESP/SANTANDER for Dr. Teixeira's post-doc scholarship in MadridPeer reviewe

Cirurgia Com Tela Para Correção De Prolapso De Parede Anterior: Metanálise

Purpose Pelvic organ prolapse (POP) is a major health issue worldwide, affecting 6–8% of women. The most affected site is the anterior vaginal wall. Multiple procedures and surgical techniques have been used, with or without the use of vaginal meshes, due to common treatment failure, reoperations, and complication rates in some studies. Methods Systematic review of the literature and meta-analysis regarding the use of vaginal mesh in anterior vaginal wall prolapse was performed. A total of 115 papers were retrieved after using the medical subject headings (MESH) terms: ‘anterior pelvic organ prolapse OR cystocele AND surgery AND (mesh or colporrhaphy)’ in the PubMed database. Exclusion criteria were: follow-up shorter than 1 year, use of biological or absorbable meshes, and inclusion of other vaginal wall prolapses. Studies were put in a data chart by two independent editors; results found in at least two studies were grouped for analysis. Results After the review of the titles by two independent editors, 70 studies were discarded, and after abstract assessment, 18 trials were eligible for full text screening. For final screening and meta-analysis, after applying the Jadad score ( > 2), 12 studies were included. Objective cure was greater in the mesh surgery group (odds ratio [OR] = 1,28 [1,07–1,53]), which also had greater blood loss (mean deviation [MD] = 45,98 [9,72–82,25]), longer surgery time (MD = 15,08 [0,48–29,67]), but less prolapse recurrence (OR = 0,22 [01,3–0,38]). Dyspareunia, symptom resolution and reoperation rates were not statistically different between groups. Quality of life (QOL) assessment through the pelvic organ prolapse/urinary incontinence sexual questionnaire (PISQ-12), the pelvic floor distress inventory (PFDI-20), the pelvic floor impact questionnaire (PFIQ-7), and the perceived quality of life scale (PQOL) was not significantly different. Conclusions Anterior vaginal prolapse mesh surgery has greater anatomic cure rates and less recurrence, although there were no differences regarding subjective cure, reoperation rates and quality of life. Furthermore, mesh surgery was associated with longer surgical time and greater blood loss. Mesh use should be individualized, considering prior history and risk factors for recurrence. © 2016 by Thieme Publicações Ltda, Rio de Janeiro, Brazil.38735636

Cirurgia com tela para correção de prolapso de parede anterior: metanálise

Pelvic organ prolapse (POP) is a major health issue worldwide, affecting 6–8% of women. The most affected site is the anterior vaginal wall. Multiple procedures and surgical techniques have been used, with or without the use of vaginal meshes, due to common treatment failure, reoperations, and complication rates in some studies. Methods Systematic review of the literature and meta-analysis regarding the use of vaginal mesh in anterior vaginal wall prolapse was performed. A total of 115 papers were retrieved after using the medical subject headings (MESH) terms: ‘anterior pelvic organ prolapse OR cystocele AND surgery AND (mesh or colporrhaphy)’ in the PubMed database. Exclusion criteria were: follow-up shorter than 1 year, use of biological or absorbable meshes, and inclusion of other vaginal wall prolapses. Studies were put in a data chart by two independent editors; results found in at least two studies were grouped for analysis. Results After the review of the titles by two independent editors, 70 studies were discarded, and after abstract assessment, 18 trials were eligible for full text screening. For final screening and meta-analysis, after applying the Jadad score ( > 2), 12 studies were included. Objective cure was greater in the mesh surgery group (odds ratio [OR] = 1,28 [1,07–1,53]), which also had greater blood loss (mean deviation [MD] = 45,98 [9,72–82,25]), longer surgery time (MD = 15,08 [0,48–29,67]), but less prolapse recurrence (OR = 0,22 [01,3–0,38]). Dyspareunia, symptom resolution and reoperation rates were not statistically different between groups. Quality of life (QOL) assessment through the pelvic organ prolapse/urinary incontinence sexual questionnaire (PISQ-12), the pelvic floor distress inventory (PFDI-20), the pelvic floor impact questionnaire (PFIQ-7), and the perceived quality of life scale (PQOL) was not significantly different. Conclusions Anterior vaginal prolapse mesh surgery has greater anatomic cure rates and less recurrence, although there were no differences regarding subjective cure, reoperation rates and quality of life. Furthermore, mesh surgery was associated with longer surgical time and greater blood loss. Mesh use should be individualized, considering prior history and risk factors for recurrence.387356364Prolapso de órgãos pélvicos é problema de saúde públicas, sendo o mais comum o anterior. Para tratamento são utilizadas cirurgias, com ou sem telas. O uso de telas é para diminuir recidivas, mas não h á consenso. Métodos: Foi realizada revisão da literatura e metanálise, sobre uso de telas na correção do prolapso anterior. Base de dados foi PUBMED , com termos (MESH): “Anterior Pelvic Organ OR Cystocele AND Surgery AND (Mesh or Colporrhaphy)”. Critérios de exclusão foram: seguimento menor que 1 ano, telas biológicas ou absorvíveis. Resultados: foram avaliados 115 artigos. Após revisão dos títulos, 70 estudos foram descartados e 18 após leitura de resumos. Após critérios de Jadad (>2), 12 estudos foram incluídos. Análise estatística foi razão de risco ou diferença entre médias dos grupos, e as análises com grande heterogeneidade foram avaliadas através de análise de efeito aleatório. Resultados: Cura objetiva foi superior no grupo com tela - OR 1,28 (1,07-1,53, p ≤ 0,00001), maior perda sanguínea - diferença média (MD) 45,98 (9,72-82,25, p = 0,01), tempo cirúrgico mais longo - MD 15,08 (0,48-29,67, p = 0,04), porém menor recorrência - OR 0,22 (0,13-0,38, p = 0,00001), não apresentando maior resolução dos sintomas - OR 1,93 (0,83-4,51, p = 0,15). Dispareunia e taxa de reoperação também não foram diferentes entre grupos. Qualidade de vida não apresentou diferença. Conclusões: Cirurgia com tela para prolapso vaginal anterior apresenta melhor taxa de cura anatômica e menor recorrência, sem diferenças cura subjetiva, reoperação e qualidade de vida. Há maior tempo cirúrgico e perda sanguínea. Uso de telas deve ser individualizado