A mean-field Babcock-Leighton solar dynamo model with long-term variability

Dynamo models relying on the Babcock-Leighton mechanism are successful in reproducing most of the solar magnetic field dynamical characteristics. However, considering that such models operate only above a lower magnetic field threshold, they do not provide an appropriate magnetic field regeneration process characterizing a self-sustainable dynamo. In this work we consider the existence of an additional \alpha-effect to the Babcock-Leighton scenario in a mean-field axisymmetric kinematic numerical model. Both poloidal field regeneration mechanisms are treated with two different strength-limiting factors. Apart from the solar anti-symmetric parity behavior, the main solar features are reproduced: cyclic polarity reversals, mid-latitudinal equatorward migration of strong toroidal field, poleward migration of polar surface radial fields, and the quadrature phase shift between both. Long-term variability of the solutions exhibits lengthy periods of minimum activity followed by posterior recovery, akin to the observed Maunder Minimum. Based on the analysis of the residual activity during periods of minimum activity, we suggest that these are caused by a predominance of the \alpha-effect over the Babcock-Leighton mechanism in regenerating the poloidal field.Comment: 21 pages, 6 figure

Disaster Resilience Versus Ecological Resilience and the Proposed Second Causeway to South Padre Island

The barrier island of South Padre is located off the coast of Texas’s southern tip in Cameron County and is a popular tourist destination with over 4 million annual visits. The only road access to and from the island is a four-lane causeway, 2.3 miles in length, that routinely experiences heavy traffic. Twenty years ago, a barge crashed into the Queen Isabella Causeway, destroying a portion of the bridge. It quickly became apparent how reliant South Padre Island (SPI) is on the causeway and raised questions regarding its lack of disaster resilience. Local boosters and government responded by proposing and planning for the construction of a second causeway that would provide an additional emergency response route and facilitate economic development. However, the planned location for the new bridge crosses through sensitive seagrass beds that this construction would permanently fragment. The habitats for numerous threatened and endangered species would be destroyed, thereby reducing the ecological resilience of the area. Social–ecological theory focuses on the interconnectedness between humans and ecosystems and their symbiotic nature. Yet in the case of SPI, these two dimensions of social–ecological resiliency are in competition with one another. The proposed causeway would ostensibly enhance disaster preparedness and foster economic development but at the expense of the degradation of crucial ecological habitats. This case study provides insight into the contradictions between ecological resilience and disaster resilience from the standpoint of various stakeholders

Unravelling the Mechanics of Knitted Fabrics Through Hierarchical Geometric Representation

Knitting interloops one-dimensional yarns into three-dimensional fabrics that exhibit behaviours beyond their constitutive materials. How extensibility and anisotropy emerge from the hierarchical organization of yarns into knitted fabrics has long been unresolved. We sought to unravel the mechanical roles of tensile mechanics, assembly and dynamics arising from the yarn level on fabric nonlinearity by developing a yarn-based dynamical model. This physically validated model captures the fundamental mechanical response of knitted fabrics, analogous to flexible metamaterials and biological fiber networks due to geometric nonlinearity within such hierarchical systems. We identify the dictating factors of the mechanics of knitted fabrics, highlighting the previously overlooked but critical effect of pre-tension. Fabric anisotropy originates from observed yarn--yarn rearrangements during alignment dynamics and is topology-dependent. This yarn-based model also provides design flexibility of knitted fabrics to embed functionalities by allowing variation in both geometric configuration and material property. Our hierarchical approach to build up a knitted fabrics computationally modernizes an ancient craft and represents a first step towards mechanical programmability of knitted fabrics in wide engineering applications

Medidas de protección en víctimas de violencia familiar y su eficacia en la comisaría de Lambayeque

El presente trabajo presenta un objetivo general el cual es determinar en qué magnitud se da cumplimiento a las medidas de protección en víctimas de violencia familiar en la jurisdicción de la Comisaría de Lambayeque- - Enero-Diciembre 2021, así mismo, tiene como objetivos específicos identificar la suficiencia del personal policial así como la logística empleada que generan condiciones en la ejecución de medidas de protección a las víctimas de violencia familiar y finalmente observar la legislación vigente en temas relacionados con las medidas provisionales. La técnica que se utiliza para la recolección de datos es la encuesta y el análisis de registro documental. En el presente trabajo la metodología utilizada fue de investigación básica, para el procesamiento y análisis de información se realizó el procesamiento de datos, mediante el uso de Microsoft Excel. En la investigación se determinó que el daño causado a las víctimas por casos de agresión intrafamiliar es por deficiencias al momento de implementar medidas de protección. Se llegó a concluir que las medidas de protección resultan ineficaces debido a la falta de recursos, ya sea humano, logístico y administrativo que garanticen una efectiva aplicación de estas medidas emitidas de los Juzgados de familia

Estrategia de realidad aumentada en Instagram y el engagement online de una marca de vino en Lima-Perú 2022

La presente investigación contribuirá a determinar la relación entre una estrategia de realidad aumentada en Instagram y el engagement online, mediante el análisis de una experiencia de RA creada por una marca de vino, lo cual fue necesario para entender el uso de esta tecnología en el sector comercial actual. Se tiene como objetivo general determinar la relación entre la estrategia de realidad aumentada en Instagram y el engagement online de una marca de vino en Lima - Perú 2022. Esta investigación es tipo aplicada y presenta un nivel descriptivo - correlacional, ya que tiene como objetivo analizar y describir la relación entre las 2 variables de estudio: Realidad Aumentada y Engagement. Asimismo, presenta un enfoque cuantitativo porque se utilizó la encuesta como técnica de recolección de datos. La investigación concluye que una experiencia de Realidad Aumentada tiene una relación alta y significativa con el engagement online de una marca, ya que proporciona experiencias y un contenido de valor auténtico, generando con esto una mayor visibilidad, participación e impacto positivo en la percepción de la marca, fortaleciendo así la relación entre los usuarios y la marca

Annual changes in the Biodiversity Intactness Index in tropical and subtropical forest biomes, 2001–2012

Few biodiversity indicators are available that reflect the state of broad-sense biodiversity—rather than of particular taxa—at fine spatial and temporal resolution. One such indicator, the Biodiversity Intactness Index (BII), estimates how the average abundance of the native terrestrial species in a region compares with their abundances in the absence of pronounced human impacts. We produced annual maps of modelled BII at 30-arc-second resolution (roughly 1 km at the equator) across tropical and subtropical forested biomes, by combining annual data on land use, human population density and road networks, and statistical models of how these variables affect overall abundance and compositional similarity of plants, fungi, invertebrates and vertebrates. Across tropical and subtropical biomes, BII fell by an average of 1.9 percentage points between 2001 and 2012, with 81 countries seeing an average reduction and 43 an average increase; the extent of primary forest fell by 3.9% over the same period. We did not find strong relationships between changes in BII and countries’ rates of economic growth over the same period; however, limitations in mapping BII in plantation forests may hinder our ability to identify these relationships. This is the first time temporal change in BII has been estimated across such a large region

Progeny-testing of full-sibs IBD in a SSC2 QTL region highlights epistatic interactions for fatness traits in pigs

<p>Abstract</p> <p>Background</p> <p>Many QTL have been detected in pigs, but very few of them have been fine-mapped up to the causal mutation. On SSC2, the <it>IGF2</it>-intron3-G3072A mutation has been described as the causative polymorphism for a QTL underlying muscle mass and backfat deposition, but further studies have demonstrated that at least one additional QTL should segregate downstream of this mutation. A marker-assisted backcrossing design was set up in order to confirm the segregation of this second locus, reduce its confidence interval and better understand its mode of segregation.</p> <p>Results</p> <p>Five recombinant full-sibs, with genotype G/G at the <it>IGF2 </it>mutation, were progeny-tested. Only two of them displayed significant QTL for fatness traits although four inherited the same paternal and maternal chromosomes, thus exhibiting the same haplotypic contrast in the QTL region. The hypothesis of an interaction with another region in the genome was proposed to explain these discrepancies and after a genome scan, four different regions were retained as potential interacting regions with the SSC2 QTL. A candidate interacting region on SSC13 was confirmed by the analysis of an F2 pedigree, and in the backcross pedigree one haplotype in this region was found to mask the SSC2 QTL effect.</p> <p>Conclusions</p> <p>Assuming the hypothesis of interactions with other chromosomal regions, the QTL could be unambiguously mapped to a 30 cM region delimited by recombination points. The marker-assisted backcrossing design was successfully used to confirm the segregation of a QTL on SSC2 and, because full-sibs that inherited the same alleles from their two parents were analysed, the detection of epistatic interactions could be performed between alleles and not between breeds as usually done with the traditional Line-Cross model. Additional analyses of other recombinant sires should provide more information to further improve the fine-mapping of this locus, and confirm or deny the interaction identified between chromosomes 2 and 13.</p

NFATc3 controls tumour growth by regulating proliferation and migration of human astroglioma cells

Calcium/Calcineurin/Nuclear Factor of Activated T cells (Ca/CN/NFAT) signalling pathway is the main calcium (Ca2+) dependent signalling pathway involved in the homeostasis of brain tissue. Here, we study the presence of NFATc members in human glioma by using U251 cells and a collection of primary human glioblastoma (hGB) cell lines. We show that NFATc3 member is the predominant member. Furthermore, by using constitutive active NFATc3 mutant and shRNA lentiviral vectors to achieve specific silencing of this NFATc member, we describe cytokines and molecules regulated by this pathway which are required for the normal biology of cancer cells. Implanting U251 in an orthotopic intracranial assay, we show that specific NFATc3 silencing has a role in tumour growth. In addition NFATc3 knock-down affects both the proliferation and migration capacities of glioma cells in vitro. Our data open the possibility of NFATc3 as a target for the treatment of glioma.This work was supported by grants from the Fondo de Investigaciones Sanitarias (FIS) Spain (PI09/0218) and Red Temática Investigación Cooperativa en Cáncer (RTICC. (RD12/0036/0027) Grants from the Spanish Ministry (MINECO) (SAF2016-76451) to E.C.S

Cerebral white matter diffusion properties and free‐water with obstructive sleep apnea severity in older adults

Characterizing the effects of obstructive sleep apnea (OSA) on the aging brain could be key in our understanding of neurodegeneration in this population. Our objective was to assess white matter properties in newly diagnosed and untreated adults with mild to severe OSA. Sixty‐five adults aged 55 to 85 were recruited and divided into three groups: control (apnea‐hypopnea index ≤5/hr; n = 18; 65.2 ± 7.2 years old), mild (>5 to ≤15 hr; n = 27; 64.2 ± 5.3 years old) and moderate to severe OSA (>15/hr; n = 20; 65.2 ± 5.5 years old). Diffusion tensor imaging metrics (fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity, and mean diffusivity) were compared between groups with Tract‐Based Spatial Statistics within the white matter skeleton created by the technique. Groups were also compared for white matter hyperintensities volume and the free‐water (FW) fraction. Compared with controls, mild OSA participants showed widespread areas of lower diffusivity (p < .05 corrected) and lower FW fraction (p < .05). Participants with moderate to severe OSA showed lower AD in the corpus callosum compared with controls (p < .05 corrected). No between‐group differences were observed for FA or white matter hyperintensities. Lower white matter diffusivity metrics is especially marked in mild OSA, suggesting that even the milder form may lead to detrimental outcomes. In moderate to severe OSA, competing pathological responses might have led to partial normalization of diffusion metrics

Acidic microenvironment plays a key role in human melanoma progression through a sustained exosome mediated transfer of clinically relevant metastatic molecules

Background: Microenvironment cues involved in melanoma progression are largely unknown. Melanoma is highly influenced in its aggressive phenotype by the changes it determinates in its microenvironment, such as pH decrease, in turn influencing cancer cell invasiveness, progression and tissue remodelling through an abundant secretion of exosomes, dictating cancer strategy to the whole host. A role of exosomes in driving melanoma progression under microenvironmental acidity was never described. Methods: We studied four differently staged human melanoma lines, reflecting melanoma progression, under microenvironmental acidic pHs pressure ranging between pH 6.0-6.7. To estimate exosome secretion as a function of tumor stage and environmental pH, we applied a technique to generate native fluorescent exosomes characterized by vesicles integrity, size, density, markers expression, and quantifiable by direct FACS analysis. Functional roles of exosomes were tested in migration and invasion tests. Then we performed a comparative proteomic analysis of acid versus control exosomes to elucidate a specific signature involved in melanoma progression. Results: We found that metastatic melanoma secretes a higher exosome amount than primary melanoma, and that acidic pH increases exosome secretion when melanoma is in an intermediate stage, i.e. metastatic non-invasive. We were thus able to show that acidic pH influences the intercellular cross-talk mediated by exosomes. In fact when exposed to exosomes produced in an acidic medium, pH naïve melanoma cells acquire migratory and invasive capacities likely due to transfer of metastatic exosomal proteins, favoring cell motility and angiogenesis. A Prognoscan-based meta-analysis study of proteins enriched in acidic exosomes, identified 11 genes (HRAS, GANAB, CFL2, HSP90B1, HSP90AB1, GSN, HSPA1L, NRAS, HSPA5, TIMP3, HYOU1), significantly correlating with poor prognosis, whose high expression was in part confirmed in bioptic samples of lymph node metastases. Conclusions: A crucial step of melanoma progression does occur at melanoma intermediate -stage, when extracellular acidic pH induces an abundant release and intra-tumoral uptake of exosomes. Such exosomes are endowed with pro-invasive molecules of clinical relevance, which may provide a signature of melanoma advancement