Super-A-polynomials for Twist Knots

We conjecture formulae of the colored superpolynomials for a class of twist knots $K_p$ where p denotes the number of full twists. The validity of the formulae is checked by applying differentials and taking special limits. Using the formulae, we compute both the classical and quantum super-A-polynomial for the twist knots with small values of p. The results support the categorified versions of the generalized volume conjecture and the quantum volume conjecture. Furthermore, we obtain the evidence that the Q-deformed A-polynomials can be identified with the augmentation polynomials of knot contact homology in the case of the twist knots.Comment: 22+16 pages, 16 tables and 5 figures; with a Maple program by Xinyu Sun and a Mathematica notebook in the ancillary files linked on the right; v2 change in appendix B, typos corrected and references added; v3 change in section 3.3; v4 corrections in Ooguri-Vafa polynomials and quantum super-A-polynomials for 7_2 and 8_1 are adde

Dengue Infection and Miscarriage: A Prospective Case Control Study

Dengue is the most prevalent mosquito-borne infection with two billion of the world's population at risk and 100 million infections every year. Dengue is increasingly important due to expansion in the vector's range, increased population density in endemic areas from urbanisation, social and environment change. Miscarriage and stillbirth is associated with dengue when the illness is severe. Dengue can also be transmitted directly from the ill mother through the placenta to the fetus in later pregnancy with variable effect to the fetus. However, dengue infection is asymptomatic to mild only in almost 90% of cases and up to 20% of pregnancies miscarry. Little is known if dengue infection in early pregnancy particularly when it is asymptomatic or mild has an effect on miscarriage. Our study explored the relationship between dengue and miscarriage by looking at recent infection rates amongst women who had miscarried and those whose pregnancies were healthy in an area were dengue is common. Our study finds a positive association between recent dengue infection and miscarriage. This finding may be important in explaining some of the miscarriages in areas where dengue is common. It is also relevant to newly pregnant women from non-dengue travelling to dengue endemic areas

IFSS, TG, FT-IR spectra of impregnated sugar palm (Arenga pinnata) fibres and mechanical properties of their composites.

This study aimed to investigate the effect of resin impregnation on the interfacial shear strength (IFSS), thermogravimetric (TG) and fourier transform infrared (FT-IR) of sugar palm (Arenga pinnata) fibres. In addition, the effect of resin impregnation on the mechanical properties of sugar palm fibre reinforced unsaturated polyester (UP) composites was also studied. The fibres were impregnated with UP via vacuum resin impregnation process at a pressure of 600 mmHg for 5 min. Composites of 10, 20, 30, 40 and 50 % fibre loadings were fabricated and tested for tensile and flexural properties. It was observed that the impregnation process caused the fibres to be enclosed by UP resin and this gave a strong influence to the increase of its interfacial bonding by the increase of its IFSS from single fibre pull-out test. It was also observed with TG and FT-IR spectra that the impregnated fibre had lower moisture uptake than the control and there was no significant increase in thermal stability of the impregnated fibre. The sequence of fibre decomposition started from the evaporation of moisture, hemicelluloses, cellulose, lignin and finally ash content and the presence of these components were proven by FT-IR spectra. For the composite specimens, due to the high interfacial bonding of the impregnated fibre and the matrix, the impregnated composites showed consistently higher tensile strength, tensile modulus, elongation at break, flexural strength, flexural modulus and toughness than the control samples. It was also observed that 30 % fibre loading gave optimum properties

Keratin-based particles for protection and restoration of hair properties

Objective Human hair is an element with unquestionable relevance in society both for women and men. Therefore, it is of great importance to develop new cosmetic products for hair care capable to restore and improve hair's characteristics. Here we explore the potential of keratinbased particles in the protection and recovery of hair mechanical properties and thermal stability. Methods Keratinbased particles were obtained by high pressure homogenization (HPH) using keratin and silk fibroin. The particles were characterized regarding size, superficial charge and polydispersity index. Their safety to cells was assessed using human skin keratinocytes. Virgin and overbleached Asian hair were treated with eight keratinbased formulations. The effect of particles on hair's mechanical properties was evaluated in terms of stiffness and tensile strength. The impact of treatments in hair thermal performance was studied using differential scanning calorimetry (DSC). Results Keratinbased particles were capable to recover and/or improve the mechanical properties of virgin and overbleached hair. Virgin hair treated with K80SF20P particles presented an improvement of the mechanical properties around 40%. An increase in keratin helix denaturation enthalpy and in surface smoothness for both types of hair was also verified after treatment. These particles demonstrated stability over time and proved to be safe when tested in human keratinocytes. Conclusion The keratinbased particles here presented have the potential to be incorporated in the development of new and effective hair care cosmetic formulations.This study was supported by FCT under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE2020 (POCI01-0145-FEDER-006684) and BioTecNorte operation (NORTE-010145-FEDER-000004) and Nanotechnology Based Functional Solutions (NORTE-01-0145- FEDER-000019) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. We also acknowledge the strategic programme UID/BIA/04050/2013 (POCI-01-0145-FEDER007569) funded by national funds through Fundação para a Ciência e a Tecnologia (FCT) and by the ERDF through the COMPETE2020 – Programa Operacional Competitividade e Internacionalização (POCI). Artur Ribeiro and Ana Tinoco thank FCT for funding the scholarships with the references SFRH/BPD/98388/2013 and SFRH/BD/ 114035/2015, respectively.info:eu-repo/semantics/publishedVersio

Glycolate Oxidase Isozymes Are Coordinately Controlled by GLO1 and GLO4 in Rice

Glycolate oxidase (GLO) is a key enzyme in photorespiratory metabolism. Four putative GLO genes were identified in the rice genome, but how each gene member contributes to GLO activities, particularly to its isozyme profile, is not well understood. In this study, we analyzed how each gene plays a role in isozyme formation and enzymatic activities in both yeast cells and rice tissues. Five GLO isozymes were detected in rice leaves. GLO1 and GLO4 are predominately expressed in rice leaves, while GLO3 and GLO5 are mainly expressed in the root. Enzymatic assays showed that all yeast-expressed GLO members except GLO5 have enzymatic activities. Further analyses suggested that GLO1, GLO3 and GLO4 interacted with each other, but no interactions were observed for GLO5. GLO1/GLO4 co-expressed in yeast exhibited the same isozyme pattern as that from rice leaves. When either GLO1 or GLO4 was silenced, expressions of both genes were simultaneously suppressed and most of the GLO activities were lost, and consistent with this observation, little GLO isozyme protein was detected in the silenced plants. In contrast, no observable effect was detected when GLO3 was suppressed. Comparative analyses between the GLO isoforms expressed in yeast and the isozymes from rice leaves indicated that two of the five isozymes are homo-oligomers composed of either GLO1 or GLO4, and the other three are hetero-oligomers composed of both GLO1 and GLO4. Our current data suggest that GLO isozymes are coordinately controlled by GLO1 and GLO4 in rice, and the existence of GLO isozymes and GLO molecular and compositional complexities implicate potential novel roles for GLO in plants

The Congenital Cataract-Linked G61C Mutation Destabilizes γD-Crystallin and Promotes Non-Native Aggregation

γD-crystallin is one of the major structural proteins in human eye lens. The solubility and stability of γD-crystallin play a crucial role in maintaining the optical properties of the lens during the life span of an individual. Previous study has shown that the inherited mutation G61C results in autosomal dominant congenital cataract. In this research, we studied the effects of the G61C mutation on γD-crystallin structure, stability and aggregation via biophysical methods. CD, intrinsic and extrinsic fluorescence spectroscopy indicated that the G61C mutation did not affect the native structure of γD-crystallin. The stability of γD-crystallin against heat- or GdnHCl-induced denaturation was significantly decreased by the mutation, while no influence was observed on the acid-induced unfolding. The mutation mainly affected the transition from the native state to the intermediate but not that from the intermediate to the unfolded or aggregated states. At high temperatures, both proteins were able to form aggregates, and the aggregation of the mutant was much more serious than the wild type protein at the same temperature. At body temperature and acidic conditions, the mutant was more prone to form amyloid-like fibrils. The aggregation-prone property of the mutant was not altered by the addition of reductive reagent. These results suggested that the decrease in protein stability followed by aggregation-prone property might be the major cause in the hereditary cataract induced by the G61C mutation

The Effect of Carbon Credits on Savanna Land Management and Priorities for Biodiversity Conservation

Carbon finance offers the potential to change land management and conservation planning priorities. We develop a novel approach to planning for improved land management to conserve biodiversity while utilizing potential revenue from carbon biosequestration. We apply our approach in northern Australia's tropical savanna, a region of global significance for biodiversity and carbon storage, both of which are threatened by current fire and grazing regimes. Our approach aims to identify priority locations for protecting species and vegetation communities by retaining existing vegetation and managing fire and grazing regimes at a minimum cost. We explore the impact of accounting for potential carbon revenue (using a carbon price of US$14 per tonne of carbon dioxide equivalent) on priority areas for conservation and the impact of explicitly protecting carbon stocks in addition to biodiversity. Our results show that improved management can potentially raise approximately US$5 per hectare per year in carbon revenue and prevent the release of 1–2 billion tonnes of carbon dioxide equivalent over approximately 90 years. This revenue could be used to reduce the costs of improved land management by three quarters or double the number of biodiversity targets achieved and meet carbon storage targets for the same cost. These results are based on generalised cost and carbon data; more comprehensive applications will rely on fine scale, site-specific data and a supportive policy environment. Our research illustrates that the duel objective of conserving biodiversity and reducing the release of greenhouse gases offers important opportunities for cost-effective land management investments

S-duality as a beta-deformed Fourier transform

An attempt is made to formulate Gaiotto's S-duality relations in an explicit quantitative form. Formally the problem is that of evaluation of the Racah coefficients for the Virasoro algebra, and we approach it with the help of the matrix model representation of the AGT-related conformal blocks and Nekrasov functions. In the Seiberg-Witten limit, this S-duality reduces to the Legendre transformation. In the simplest case, its lifting to the level of Nekrasov functions is just the Fourier transform, while corrections are related to the beta-deformation. We calculate them with the help of the matrix model approach and observe that they vanish for beta=1. Explicit evaluation of the same corrections from the U_q(sl(2)) infinite-dimensional representation formulas due to B.Ponsot and J.Teshner remains an open problem.Comment: 21 page

Age of the Association between Helicobacter pylori and Man

When modern humans left Africa ca. 60,000 years ago (60 kya), they were already infected with Helicobacter pylori, and these bacteria have subsequently diversified in parallel with their human hosts. But how long were humans infected by H. pylori prior to the out-of-Africa event? Did this co-evolution predate the emergence of modern humans, spanning the species divide? To answer these questions, we investigated the diversity of H. pylori in Africa, where both humans and H. pylori originated. Three distinct H. pylori populations are native to Africa: hpNEAfrica in Afro-Asiatic and Nilo-Saharan speakers, hpAfrica1 in Niger-Congo speakers and hpAfrica2 in South Africa. Rather than representing a sustained co-evolution over millions of years, we find that the coalescent for all H. pylori plus its closest relative H. acinonychis dates to 88–116 kya. At that time the phylogeny split into two primary super-lineages, one of which is associated with the former hunter-gatherers in southern Africa known as the San. H. acinonychis, which infects large felines, resulted from a later host jump from the San, 43–56 kya. These dating estimates, together with striking phylogenetic and quantitative human-bacterial similarities show that H. pylori is approximately as old as are anatomically modern humans. They also suggest that H. pylori may have been acquired via a single host jump from an unknown, non-human host. We also find evidence for a second Out of Africa migration in the last 52,000 years, because hpEurope is a hybrid population between hpAsia2 and hpNEAfrica, the latter of which arose in northeast Africa 36–52 kya, after the Out of Africa migrations around 60 kya