Matching structure and bargaining outcomes in buyer–seller networks

We examine the relationship between the matching structure of a bipartite (buyer-seller) network and the (expected) shares of the unit surplus that each connected pair in this network can create. We show that in different bargaining environments, these shares are closely related to the Gallai-Edmonds Structure Theorem. This theorem characterizes the structure of maximum matchings in an undirected graph. We show that the relationship between the (expected) shares and the tructure Theorem is not an artefact of a particular bargaining mechanism or trade centralization. However, this relationship does not necessarily generalize to non-bipartite networks or to networks with heterogeneous link values

High yielding synthesis of N-ethyl dehydroamino acids

Recently we reported the use of a sequence of alkylation and dehydration methodologies to obtain N-ethyl-α, β-dehydroamino acid derivatives. The application of this N-alkylation procedure to several methyl esters of β, β-dibromo and β--bromo, β-substituted dehydroamino acids protected with standard amine protecting groups was subsequently reported. The corresponding N-ethyl, β-bromo dehydroamino acid derivatives were obtained in fair to high yields and some were used as substrates in Suzuki cross coupling reactions to give N-ethyl, β, β-disubstituted dehydroalanine derivatives. Herein, we further explore N-ethylation of β-halo dehydroamino acid derivatives using triethyloxonium tetrafluoroborate as alkylating agent but substituting N,N-diisopropylethylamine for potassium tert-butoxide as auxiliary base. In these conditions, for all β-halo dehydroamino acid derivatives, reactions were complete and the N-ethylated derivative could be isolated in high yield. This method was also applied for N-ethylation of non-halogenated dehydroamino acids. Again, with all compounds the reactions were complete and the N-ethyl dehydroamino acid derivatives could be isolated in high yields. Some of these N-ethyl dehydroamino acid methyl ester derivatives were converted in high yields to their corresponding acids and coupled to an amino acid methyl ester to give N-ethyl dehydrodipeptide derivatives in good yields. Thus, this method constitutes a general procedure for high yielding synthesis of N-ethylated dehydroamino acids, which can be further applied in peptide synthesis.Foundation for Science and Technology (FCT)-Portugal and Fundo Europeu de Desenvolvimento Regional (FEDER) for financial support to Chemistry Centre of University of Minho. The NMR spectrometer Bruker Avance II+ 400 is part of the National NMR Network and was purchased in the framework of the National Program for Scientific Re-equipment; contract REDE/1517/RMN/2005, with funds from POCI 2010, FEDER and FCT

Detection and Antimicrobial Resistance Profile of Enteropathogenic (EPEC) and Shigatoxigenic Escherichia coli (STEC) in Conventional and Organic Broiler Chickens

ABSTRACT Enteropatogenic Escherichia coli (EPEC) and shigatoxigenic E. coli (STEC), are generally poultry and poultry product isolate and can cause serious human infections. Many strains may become resistant to various antimicrobials, which can hinder the treatment of bacterial diseases. Organic farming seeks to avoid the selection and frequency of antimicrobial-resistant bacteria. This study aims to verify the resistance of EPEC and STEC from organic and conventional (industrial) broiler isolates to antimicrobials. All isolates were submitted to disk diffusion test with tetracycline, gentamicin, enrofloxacin, ceftriaxone and amoxicillin + clavulanate (TET, GEN, ENO, CTX, AMC) and PCR to detect specific virulence genes for EPEC and STEC. A total of 297 E. coli strains were isolated, 213 from conventional. In organic broiler, 84 strains were isolated. The strains from the conventional broiler isolates were resistant to five antimicrobials tested: TET 48.82% (104/213), ENO 28.17% (60/213), CTX 15.49% (33/213), GEN 14.55% (31/213), and AMC 7.04% (15/213), and 9.86% (21/213) were considered multidrug-resistant. Organic chicken strains were resistant to four of the antimicrobials tested: TET 35.7% (30/84), ENO 9.5% (8/84), CTX 2.4% (2/84), GEN 4.8% (4/84). Of the strains from the organic broiler chicken isolates, only 1.2% (1/84) was considered multidrug-resistant. No EPEC and STEC were found in the organic chicken samples. The multidrug resistance was characterized in 9.52% (2/21) of the EPEC and 4.76% (1/21) of the STEC. The study demonstrated the absence of EPEC and STEC strains in organic broilers and carcasses and a lower frequency of multiresistant strains compared to conventional breeding

DNA content of a functioning chicken kinetochore

© The Author(s) 2014. In order to understand the three-dimensional structure of the functional kinetochore in vertebrates, we require a complete list and stoichiometry for the protein components of the kinetochore, which can be provided by genetic and proteomic experiments. We also need to know how the chromatin-containing CENP-A, which makes up the structural foundation for the kinetochore, is folded, and how much of that DNA is involved in assembling the kinetochore. In this MS, we demonstrate that functioning metaphase kinetochores in chicken DT40 cells contain roughly 50 kb of DNA, an amount that corresponds extremely closely to the length of chromosomal DNA associated with CENP-A in ChIP-seq experiments. Thus, during kinetochore assembly, CENP-A chromatin is compacted into the inner kinetochore plate without including significant amounts of flanking pericentromeric heterochromatin. © 2014 The Author(s).Wellcome Trust [grant number 073915]; Wellcome Trust Centre for Cell Biology (core grant numbers 077707 and 092076); Darwin Trust of Edinburg

Quantitative image analysis of polyhydroxyalkanoates inclusions from microbial mixed cultures under different SBR operation strategies

Polyhydroxyalkanoates (PHAs) produced from mixed microbial cultures (MMC), regarded as potential substitutes of petrochemical plastics, can be found as intracellular granules in various microorganisms under limited nutrient conditions and excess of carbon source. PHA is traditionally quantified by laborious and time-consuming chromatography analysis, and a simpler and faster method to assess PHA contents from MMC, such as quantitative image analysis (QIA), is of great interest. The main purpose of the present work was to upgrade a previously developed QIA methodology (Mesquita et al., 2013a, 2015) for MMC intracellular PHA contents quantification, increase the studied intracellular PHA concentration range and extend to different sequencing batch reactor (SBR) operation strategies. Therefore, the operation of a new aerobic dynamic feeding (ADF) SBR allowed further extending the studied operating conditions, dataset, and range of the MMC intracellular PHA contents from the previously reported anaerobic/aerobic cycle SBR. Nile Blue A (NBA) staining was employed for epifluorescence microscope visualization and image acquisition, further fed to a custom developed QIA. Data from each of the feast and famine cycles of both SBR were individually processed using chemometrics analysis, obtaining the correspondent partial least squares (PLS) models. The PHA concentrations determined from PLS models were further plotted against the results obtained in the standard chromatographic method. For both SBR the predicted ability was higher at the end of the feast stage than for the famine stage. Indeed, an independent feast and famine QIA data treatment was found to be fundamental to obtain the best prediction abilities. Furthermore, a promising overall correlation (R2 of 0.83) could be found combining the overall QIA data regarding the PHA prediction up to a concentration of 1785.1 mgL-1 (37.3 wt%). Thus, the results confirm that the presented QIA methodology can be seen as promising for estimating higher intracellular PHA concentrations for a larger reactors operation systems and further extending the prediction range of previous studies.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE01-0145-FEDER-000004) funded by European Regional Development Fundunder the scope ofNorte2020 - ProgramaOperacional Regional do Norte.The authors also acknowledge the financial support to Cristiano S. Leal (PTDC/EBB-EBI/103147/2008, FCOMP-01-0124-FEDER009704) and Daniela P. Mesquita through the FCT postdoctoral grant (SFRH/BPD/82558/2011).info:eu-repo/semantics/publishedVersio

Search for supersymmetric particles in scenarios with a gravitino LSP and stau NLSP

Sleptons, neutralinos and charginos were searched for in the context of scenarios where the lightest supersymmetric particle is the gravitino. It was assumed that the stau is the next-to-lightest supersymmetric particle. Data collected with the DELPHI detector at a centre-of-mass energy near 189 GeV were analysed combining the methods developed in previous searches at lower energies. No evidence for the production of these supersymmetric particles was found. Hence, limits were derived at 95% confidence level.Comment: 31 pages, 14 figure