Cosection localisation and the Quot scheme QuotSl(E)\mathrm{Quot}^{l}_{S}(\mathcal{E})

Let $\mathcal{E}$ be a locally free sheaf of rank $r$ on a smooth projective surface $S$. The Quot scheme $\mathrm{Quot}^{l}_{S}(\mathcal{E})$ of length $l$ coherent sheaf quotients of $\mathcal{E}$ is a natural higher rank generalisation of the Hilbert scheme of $l$ points of $S$. We study the virtual intersection theory of this scheme. If $C\subset S$ is a smooth canonical curve, we use cosection localisation to show that the virtual fundamental class of $\mathrm{Quot}^{l}_{S}(\mathcal{E})$ is $(-1)^{l}$ times the fundamental class of the smooth subscheme $\mathrm{Quot}^{l}_{C}(\mathcal{E}\vert_{C})\subset\mathrm{Quot}^{l}_{S}(\mathcal{E})$. We then prove a structure theorem for virtual tautological integrals over $\mathrm{Quot}^{l}_{S}(\mathcal{E})$. From this we deduce, among other things, the equality of virtual Euler characteristics $\chi^{\mathrm{vir}}(\mathrm{Quot}^{l}_{S}(\mathcal{E}))=\chi^{\mathrm{vir}}(\mathrm{Quot}^{l}_{S}(\mathcal{O}^{\oplus r}))$.Comment: Final version, to appear in Proceedings of the Royal Society

STRING and STITCH: known and predicted interactions between proteins and chemicals

Information on protein-protein and protein-chemical interactions is essential for understanding cellular functions. The STRING and STITCH web resources integrate interaction evidence derived from pathways, automatic literature mining, primary experimental data, and genomic context. The resulting interaction networks cover 1.5 million proteins from 373 organisms and 68,000 chemicals

Effects of Shell Hash on Friction Angles of Surficial Seafloor Sediments near Oysters

Oysters are hypothesized to affect the shear strength of nearby surficial seafloor sediment as fragments of oyster shells (shell hash) are typically more angular relative to sand particles alone, among other differences. Resistance to shearing is well characterized by the friction angle, which is estimated in this study from vacuum triaxial laboratory and portable free-fall penetrometer field tests. Friction angles of sediment with shell hash were higher relative to those of sediment without shell hash (via hydrochloric acid treatment) on average by about 19% (36.0°–30.2°, respectively). Triaxial confining pressures ranged between 2.1 and 49.0 kPa to simulate subtidal and intertidal aquatic conditions. Regularity (average of particle roundness and sphericity) values of sediment samples with shell hash were found to be less than those of samples without by about 6% (0.66 and 0.70, respectively), which indicates the particle shapes of the former are, overall, more angular and less spherical. Further study and methodology improvements are needed to decrease the approximate 9° friction angle discrepancy estimated from field- and laboratory-based tests. Knowing oysters have the potential to increase sediment shearing resistance helps establish a pathway of how shellfish colonies may contribute to mitigating surficial erosion around coastal infrastructure

Restoration of Pigeon Guillemot Nesting Habitat Through Removal of Introduced Predators

The 1989 Exxon Valdez oil spill (EVOS) in Prince William Sound, Alaska provided impetus for a great deal of research into the ecosystems of the Northern Gulf of Alaska. Buried within the multitude of resulting impacts, which included hundreds of thousands of oiled seabirds and dramatic ecosystem shifts in the North Pacific Ocean, was the steady decline of pigeon guillemots (Cepphus columba) at the historically important nesting area in the Naked Island Group of central Prince William Sound. The cause of this decline, however, perplexed researchers for decades, as it both preceded and outlasted the effects attributed to the spill. Guillemots are a seabird in the auk family (Alcidae) that nest in burrows and other natural crevices. Monitoring of guillemots nesting at the Naked Island Group in Prince William Sound began in 1979, 10 years prior to EVOS, and have continued intermittently until the present. Between 1979 and 2008, the number of guillemots nesting at the Naked Island Group declined by 95%. In 2008, when a remnant population of only about 100 guillemots was still attending the Naked Island Group, it came to light that American mink (Neovison vison), a voracious predator of ground-nesting birds, had been intentionally introduced to the Naked Island Group throughout the 1970’s to provide trapping opportunities. In 2012, we initiated research to test whether removing mink from the Naked Island Group would allow the local guillemot population to recover. Lethal trapping efforts to remove mink from the islands were initiated in 2014 and continued through 2018. The last mink was captured in the spring of 2016, and the last mink sign (i.e. tracks or scat) was observed in the spring of 2017. By 2018, the Naked Island Group appeared to be free of mink. Removal of introduced predators is a widespread and effective tool for restoration of island nesting birds. Despite its pervasive use, the effects of predator removal on target species for conservation remains understudied. In addition, no predator removal efforts in North America have targeted American mink. In order to evaluate the effects of mink removal on the guillemot population at the Naked Island Group, I used a Before-After, Control-Impact (BACI) study design. Specifically, I compared trends in population counts of guillemots at the Naked Island Group before and after the removal of mink to the population trends at a number of nearby mink-free islands. To augment this experiment, I measured six variables that have been linked to guillemot nesting success and productivity, due to either predation pressure or forage fish availability. I hypothesized that the abundance of guillemot nests, nestling survival rates, and guillemot use of nest sites vulnerable to land-based predators would all increase following the removal of mink. Also, I predicted that guillemot chick growth rates, diet composition, and meal delivery rates to nests would not be affected by mink removal and would vary instead due to stochastic environmental factors as they affect forage fish availability. Results from my BACI experimental design indicated that guillemot numbers at the Naked Island Group increased dramatically following the initiation of mink removal efforts, as compared to the control sites. Prior to mink removal, guillemot counts at the Naked Island Group decreased from 146 birds in 2007 to only 69 in 2014. Following mink removal, guillemot counts immediately began to increase, reaching 167 birds by 2018. During this same time period, I observed no clear change in guillemot abundance at control islands where guillemot population counts consistently, though slowly, increased from 2008 to 2018. Concurrent with increases in the number of guillemots at the Naked Island Group following the removal of mink, I also observed increases in guillemot nest abundance, nestling survival rates, and the proportion of guillemot nest in sites vulnerable to mink predation (i.e. burrows instead of crevices in cliffs). These changes in combination suggested that the removal of mink resulted in improved quality of nesting habitat available for guillemots and the initiation of recovery of the guillemot population. Foraging conditions for guillemots also appeared to have been favorable at the Naked Island Group during my study period, and these would not be expected to be related to mink removal. Guillemot chick growth rates and meal delivery rates were significantly higher than those observed during the period when mink were present at the Naked Island Group, and I found evidence that guillemot diet composition contained a larger percentage of high-quality prey than had been documented in earlier studies. This suggests that foraging conditions guillemots have improved compared to the period when mink predation pressure was at its peak, which coincided with the aftermath of EVOS. As EVOS has been linked to declines in the abundance of high-quality prey, such as schooling forage fish, the improved foraging conditions that I observed were likely due to the recovery of prey resources following EVOS. All of these factors, both top-down and bottom-up, indicate recently improved conditions for guillemots nesting at the Naked Island Group and in central Prince William Sound. I expected the guillemot nesting population to grow at the Naked Island Group following the removal of an introduced mammalian predator; however, the observed rate of increase in guillemot numbers at the Naked Island Group exceeded my expectations to such an extent that it is unlikely that intrinsic growth (population growth through reproduction) alone was responsible. This suggests that immigration of guillemots from elsewhere in Prince William Sound drove much of the initial recovery in guillemot numbers at the Naked Island Group following the removal of mink. In conclusion, I demonstrated that the number of pigeon guillemots nesting at the Naked Island Group had been limited by mink predation, and that the removal of mink initiated the recovery of this historically important sub-population. The initial rate of increase in guillemot numbers was likely primarily the result of immigration to the Naked Island Group from other breeding colonies within the Sound. In addition, currently favorable foraging conditions and positive guillemot population trends at nearby control islands suggest that conditions are conducive to the continued recovery of the sub-population of pigeon guillemots at the Naked Island Group, as well as the Prince William Sound population at large

Local variations in spatial synchrony of influenza epidemics

Background: Understanding the mechanism of influenza spread across multiple geographic scales is not complete. While the mechanism of dissemination across regions and states of the United States has been described, understanding the determinants of dissemination between counties has not been elucidated. The paucity of high resolution spatial-temporal influenza incidence data to evaluate disease structure is often not available. Methodology and Findings: We report on the underlying relationship between the spread of influenza and human movement between counties of one state. Significant synchrony in the timing of epidemics exists across the entire state and decay with distance (regional correlation = 62%). Synchrony as a function of population size display evidence of hierarchical spread with more synchronized epidemics occurring among the most populated counties. A gravity model describing movement between two populations is a stronger predictor of influenza spread than adult movement to and from workplaces suggesting that non-routine and leisure travel drive local epidemics. Conclusions: These findings highlight the complex nature of influenza spread across multiple geographic scales. © 2012 Stark et al

Preparation of nano-gypsum from anhydrite nanoparticles: Strongly increased Vickers hardness and formation of calcium sulfate nano-needles

The preparation of calcium sulfate by flame synthesis resulted in the continuous production of anhydrite nanoparticles of 20-50nm size. After compaction and hardening by the addition of water, the anhydrite nanoparticles reacted to nano-gypsum which was confirmed by X-ray diffraction, diffuse reflectance IR spectroscopy and thermal analysis. Mechanical properties were investigated in terms of Vickers hardness and revealed an up to three times higher hardness of nano-gypsum if compared to conventional micron-sized construction material. The improved mechanical properties of nano-gypsum could in part be due to the presence of calcium sulfate nano-needles in the nano-gypsum as showed by electron microscop

Monogenic gene variants in lung transplant recipients with usual interstitial pneumonia

Aim The prevalence of monogenic disease-causing gene variants in lung transplant recipients with idiopathic pulmonary fibrosis is not fully known. Their impact on clinical outcomes before and after transplantation requires more evidence. Patients and methods We retrospectively performed sequence analysis of genes associated with pulmonary fibrosis in a cohort of 23 patients with histologically confirmed usual interstitial pneumonia that had previously undergone double lung transplantation. We evaluated the impact of confirmed molecular diagnoses on disease progression, clinical outcomes and incidence of acute rejection or chronic lung allograft dysfunction after transplantation. Results 15 patients out of 23 (65%) had a variant in a gene associated with interstitial lung disease. 11 patients (48%) received a molecular diagnosis, of which nine involved genes for telomerase function. Five diagnostic variants were found in the gene for Telomerase reverse transcriptase. Two of these variants, p.(Asp684Gly) and p.(Arg774*), seemed to be enriched in Finnish lung transplant recipients. Disease progression and the incidence of acute rejection and chronic lung allograft dysfunction was similar between patients with telomere-related disease and the rest of the study population. The incidence of renal or bone marrow insufficiency or skin malignancies did not differ between the groups. Conclusion Genetic variants are common in lung transplant recipients with pulmonary fibrosis and are most often related to telomerase function. A molecular diagnosis for telomeropathy does not seem to impact disease progression or the risk of complications or allograft dysfunction after transplantation.Peer reviewe

The Production of Biogenic Silica from Different South African Agricultural Residues through a Thermo-Chemical Treatment Method

A thermo-chemical treatment method was used to produce biogenic amorphous silica from South African sugarcane and maize residues. Different fractions of South African sugarcane (leaves, pith, and fiber) were processed for silica production. The biomass samples were leached with either 7 wt% citric acid or 7 wt% sulfuric acid at 353 K for 2 h prior to being rinsed, dried and combusted using a four-step program ranging from room temperature to 873 K in a furnace. The characterization of the pre-treated biomass samples was conducted using thermogravimetric analysis (TG/DTA), X-ray fluorescence analysis (XRF) and elemental analysis (CHN), while the final products were characterized by XRF, X-ray diffraction (XRD), elemental analysis, nitrogen physisorption and scanning electron microscopy (SEM). Citric acid pre-treatment proved to be an attractive alternative to mineral acids. Amorphous biogenic silica was produced from sugarcane leaves in good quality (0.1 wt% residual carbon and up to 99.3 wt% silica content). The produced biogenic silica also had great textural properties such as a surface area of up to 323 m2 g−1, average pore diameter of 5.0 nm, and a pore volume of 0.41 cm3 g−1

STRING 8—a global view on proteins and their functional interactions in 630 organisms

Functional partnerships between proteins are at the core of complex cellular phenotypes, and the networks formed by interacting proteins provide researchers with crucial scaffolds for modeling, data reduction and annotation. STRING is a database and web resource dedicated to protein-protein interactions, including both physical and functional interactions. It weights and integrates information from numerous sources, including experimental repositories, computational prediction methods and public text collections, thus acting as a meta-database that maps all interaction evidence onto a common set of genomes and proteins. The most important new developments in STRING 8 over previous releases include a URL-based programming interface, which can be used to query STRING from other resources, improved interaction prediction via genomic neighborhood in prokaryotes, and the inclusion of protein structures. Version 8.0 of STRING covers about 2.5 million proteins from 630 organisms, providing the most comprehensive view on protein-protein interactions currently available. STRING can be reached at http://string-db.or