Constructing monotone homotopies and sweepouts

This article investigates when homotopies can be converted to monotone homotopies without increasing the lengths of curves. A monotone homotopy is one which consists of curves which are simple or constant, and in which curves are pairwise disjoint. We show that, if the boundary of a Riemannian disc can be contracted through curves of length less than $L$, then it can also be contracted monotonously through curves of length less than $L$. This proves a conjecture of Chambers and Rotman. Additionally, any sweepout of a Riemannian $2$-sphere through curves of length less than $L$ can be replaced with a monotone sweepout through curves of length less than $L$. Applications of these results are also discussed.Comment: 16 pages, 6 figure

Doenças fúngicas em erva-mate

“Erva mate” is a native tree, which is very important for the gaucho culture mainly because it serves as raw material for the traditional mate, and other products. Due to the high disease incidence in the “erva mate” plantations and nursery, the lack of information related to the pathogens that occur in this culture and its proper management, many farmers have abandoned these areas to cultivate major crops. This study aimed conduct a survey and identification of major diseases that occur in “erva mate” in the Alto Uruguai Gaucho region. For this, soil samples were collected for posterior serial dilution and quantification of colony forming units (CFUs), and aerial part samples of unhealthy plants for later identification of present pathogens. In the aerial part samples, it was found that the highest incidence in “erva mate” plantations and nurseries was the Fusarium genus, and also identified genre fungi as Colletotrichum, Cylindrocladium and saprophytes as Rhizopus and Cladosporium. Furthermore, it was evident the presence of genus Trichoderma in the soil samples, which is important since this is an antagonist of Fusarium species that are potentially pathogenic to this culture.A erva-mate é uma espécie nativa, que representa grande importância para a cultura gaúcha principalmente, visto que serve de matéria-prima para o tradicional chimarrão, além de outros produtos. Devido à alta incidência de doenças nos ervais e viveiros, a falta de informações relacionadas aos patógenos que ocorrem nesta cultura e seu devido manejo, muitos produtores tem abandonado estas áreas para o cultivo de grandes culturas. Este trabalho teve por objetivo fazer um levantamento e identificação das principais doenças que ocorrem na erva-mate na região do Alto Uruguai Gaúcho. Para isso foram coletadas amostras de solo, para posterior diluição serial e quantificação de unidades formadoras de colônias (UFCs), além de amostras de parte aérea das plantas doentes, para identificação dos patógenos presentes. Nas amostras de parte aérea, verificou-se que a maior incidência foi de doenças fúngicas do gênero Fusarium, sendo também identificados fungos dos gêneros Colletotrichum, Cylindrocladium e saprófitas como Rhizopus e Cladosporium. Além disso, foi evidente a presença do gênero Trichoderma nas amostras de solo, fato importante visto que este é um antagonista de espécies do gênero Fusarium que tenham potencial patogênico à cultura

Processo Para Produção De Alcoois De Lanolina Com Etapas Adicionais Para Obtenção De ácidos De Lanolina

Processo para produção de álcoois de lanolina com etapas adicionais para obtenção de ácidos de lanolina, que compreende que a lanolina seja saponificada usando-se uma solução etanólica cáustica, como hidróxido de potássio, e neutralizada com uma solução aquosa ácida, como ácido sulfúrico; a seguir, a fase orgânica é decantada, separada e lavada; segue com a precipitação dos ácidos de lanolina com óxido de cálcio e extração dos álcoois de lanolina com um solvente apolar, como acetona, sendo que após separação da fase sólida, a fase com acetona é concentrada até obtenção do álcool de lanolina; a seguir, é feito o branqueamento do álcool com água oxigenada, para obter o álcool de lanolina com rendimento de 92%.BR9905418 (C1); BR9905418 (A)C11B5/00C11B11/00C11B5/00A61K7/48C11B11/00BR19999905418C11B5/00C11B11/00C11B5/00A61K7/48C11B11/0

L-Lactic Acid Production by Lactobacillus rhamnosus

Lactic acid has been shown to have the most promising application in biomaterials as poly(lactic acid). L. rhamnosus ATCC 10863 that produces L-lactic acid was used to perform the fermentation and molasses was used as substrate. A solution containing 27.6 g/L of sucrose (main composition of molasses) and 3.0 g/L of yeast extract was prepared, considering the final volume of 3,571 mL (14.0% (v/v) inoculum). Batch and fed batch fermentations were performed with temperature of 43.4°C and pH of 5.0. At the fed batch, three molasses feed were applied at 12, 24, and 36 hours. Samples were taken every two hours and the amounts of lactic acid, sucrose, glucose, and fructose were determined by HPLC. The sucrose was barely consumed at both processes; otherwise the glucose and fructose were almost entirely consumed. 16.5 g/L of lactic acid was produced at batch and 22.0 g/L at fed batch. Considering that lactic acid was produced due to the low concentration of the well consumed sugars, the final amount was considerable. The cell growth was checked and no substrate inhibition was observed. A sucrose molasses hydrolysis is suggested to better avail the molasses fermentation with this strain, surely increasing the L-lactic acid

Sensorische Anwendungen der kalorimetrischen Detektion mit enzymatischer Erkennung

Am Institut für Physikalische Chemie der TU Bergakademie Freiberg wurden auf der Grundlage integrierter Schaltkreise im batch-mode und flow-mode arbeitende Wärmeflusskalorimeter (IC-Kalorimeter) entwickelt. Der Miniaturisierungsgrad dieser kalorimetrischen Systeme erlaubt verschiedenste Sensoranwendungen. Der vorliegende Beitrag soll die Möglichkeiten der Kombination des universell anwendbaren kalorimetrischen Messprinzips mit der hohen Spezifität der enzymatischen Katalyse zeigen. So können kalorimetrische Untersuchungen enzymatisch katalysierter Reaktionen unter analytischen Gesichtspunkten wie der Konzentrationsbestimmung von Substraten für die klinische Diagnostik oder die Überwachung biotechnologischer Prozesse eingesetzt werden. Andererseits wird die Ermittlung kinetischer Parameter aus kalorimetrischen Messkurven mit dem Ziel der Bestimmung von Enzymaktivitäten und zur Quantifizierung von Inhibitoren verfolgt

Unravelling the stomach contents of fish and crab species from Cananéia, São Paulo: Are they eating plastic?

Plastic pollution represents a threat to marine ecosystems and has therefore been gaining space in the realm of public interest. In this study, we investigated the ingestion of food and non-food items (i.e., plastic particles) by fish and crabs. These animals are commonly collected by trawling with a double-ring net along the coast of Cananéia, state of São Paulo, Brazil; some of them are consumed as food by the local population. Fish and crab stomachs were removed and dissected, and their contents were examined under a stereoscopic microscope with an image-capturing system. The presence or absence of plastic was also registered. We examined 139 specimens of 16 fish species and 143 specimens of four crab species. The most frequent food items found in fish were unidentified food, followed by crustaceans, molluscs, polychaetes, and other fish; in crabs, the items were unidentified food, followed by crustaceans, molluscs and fish. Plastic particles were found in all fish species, representing 47.5% of the individuals analysed. In crabs, the incidence of plastic was lower, occurring in only two species (5% in Callinectes danae and 3% in C. ornatus). Only four fish species analysed had previous records of plastic ingestion in the scientific literature. The high incidence of microplastics in our study is worrying because they negatively affect the animals’ lives and can be transferred through the tropic web to top predators, including humans, through the ingestion of contaminated animals

Proposal for Quantum Simulation via All-Optically Generated Tensor Network States

We devise an all-optical scheme for the generation of entangled multimode photonic states encoded in temporal modes of light. The scheme employs a nonlinear down-conversion process in an optical loop to generate one- and higher-dimensional tensor network states of light. We illustrate the principle with the generation of two different classes of entangled tensor network states and report on a variational algorithm to simulate the ground-state physics of many-body systems. We demonstrate that state-of-the-art optical devices are capable of determining the ground-state properties of the spin-1/2 Heisenberg model. Finally, implementations of the scheme are demonstrated to be robust against realistic losses and mode mismatch.Comment: 6 pages main text plus 6 pages Supplementary Material and many figures. Updated to published version. Comments welcom

Urea-Mediated Cross-Presentation of Soluble Epstein-Barr Virus BZLF1 Protein

Soluble extracellular proteins usually do not enter the endogenous human leukocyte antigen (HLA) I–dependent presentation pathway of antigen-presenting cells, strictly impeding their applicability for the re-stimulation of protein-specific CD8+ cytotoxic T lymphocytes (CTL). Here we present for the Epstein-Barr virus (EBV) BZLF1 a novel strategy that facilitates protein translocation into antigen-presenting cells by its solubilisation in high molar urea and subsequent pulsing of cells in presence of low molar urea. Stimulation of PBMC from HLA-matched EBV-seropositive individuals with urea-treated BZLF1 but not untreated BZLF1 induces an efficient reactivation of BZLF1-specific CTL. Urea-treated BZLF1 (uBZLF1) enters antigen-presenting cells in a temperature-dependent manner by clathrin-mediated endocytosis and is processed by the proteasome into peptides that are bound to nascent HLA I molecules. Dendritic cells and monocytes but also B cells can cross-present uBZLF1 in vitro. The strategy described here has potential for use in the development of improved technologies for the monitoring of protein-specific CTL