Geometric properties of extremal domains for the pp-Laplacian operator

In this paper, we explore the geometric properties of unbounded extremal domains for the $p$-Laplacian operator in both Euclidean and hyperbolic spaces. Assuming that the nonlinearity grows at least as the nonlinearity of the eigenvalue problem, we prove that these domains exhibit remarkable geometric properties and cannot be arbitrarily wide. In two dimensions, we prove that such domains with connected complements must necessarily be balls. In the hyperbolic space, we highlight the constraints on extremal domains and the geometry of their asymptotic boundaries

Antimicrobial activity of in-situ bacterial nanocellulose-zinc oxide composites for food packaging

Active substances such as zinc oxide nanoparticles (ZnO) have been extensively explored due to their antimicrobial properties, low cost and scalability. Yet, their effectiveness is highly dependent on their morphology and specific surface area. Bacterial nanocellulose (BNC) is a suitable carrier due to its ability to transport and deliver active substances. In the case of nanocellulose-ZnO composites, conclusions drawn from antimicrobial studies are often based on only a few representatives of Gram-positive and Gram-negative bacteria. A more comprehensive study using different species and strains, and different methods to assess antimicrobial activity is required. Therefore, in this work, the antimicrobial activity of ZnO suspensions and BNCZnO films was assessed against a wide range of Gram-negative and Gram-positive bacteria using disc diffusion and viable cell count assays. Regarding the results of the disc diffusion assay, the increase of ZnO content (21–27% mZn/mBNCZnO) (in both ZnO suspensions and BNCZnO films), increased antimicrobial activity against all Gram-negative bacteria tested and some Gram-positive bacteria. In the viable cell count assay, BNCZnO films were effective against Escherichia coli (3 log reduction) and Listeria monocytogenes (1–3 log reduction) after 24 h. Low temperatures reduced the antimicrobial activity of BNCZnO.info:eu-repo/semantics/publishedVersio

Inferring epigenetic and transcriptional regulation during blood cell development with a mixture of sparse linear models

Motivation: Blood cell development is thought to be controlled by a circuit of transcription factors (TFs) and chromatin modifications that determine the cell fate through activating cell type-specific expression programs. To shed light on the interplay between histone marks and TFs during blood cell development, we model gene expression from regulatory signals by means of combinations of sparse linear regression models. Results: The mixture of sparse linear regression models was able to improve the gene expression prediction in relation to the use of a single linear model. Moreover, it performed an efficient selection of regulatory signals even when analyzing all TFs with known motifs (>600). The method identified interesting roles for histone modifications and a selection of TFs related to blood development and chromatin remodelling. Availability: The method and datasets are available from http://www.cin.ufpe.br/~igcf/SparseMix. Contact: [email protected] Supplementary information:Supplementary data are available at Bioinformatics online

Environmental and anthropogenic drivers affect the abundance of anchovy and mysids in the Guadalquivir Estuary (SW Spain)

Natural drivers, acting at various spatio-temporal scales firstly determine the distribution and abundance of species. On top of this natural forcing we usually find anthropogenic effects. Disentangling the relative influence of these two sources of variability has always been a challenge in ecology, and particularly in fisheries science. The Guadalquivir Estuary (SW Spain) serves as nursery ground for several commercial species in the Gulf of Cadiz. This study aims at quantifying the relative influence of biological (predator-prey effects), environmental (e.g. temperature, winds) and anthropogenic (dam discharges) effects on this nursery function with the focus on an important species, anchovy. We used data from a monitoring programme consisting of monthly records since 1997 at two sites: Tarfia (32 km) and Bonanza (8 km) (distance from the river mouth). Nonparametric models (GAM) were fit to the data to estimate the partial effects of the various covariates. We found positive and linear effects of temperature and mysids on anchovy abundance in both stations, while turbidity, winds and freshwater input had a negative effect, reducing fish abundance. A dam, 110 km upstream from the Guadalquivir mouth regulates freshwater discharges, directly influencing the estuarine habitat quality and extent, as captured by our models. In order to separate the anthropogenic effects from natural variability we further ran the models on a number of scenarios combining a range of dam discharges and environmental conditions. Water management stands out as a key node where potentially conflicting interests (irrigators, electric power, shipping, aquaculture, fisheries) converge. By focussing on the consequences that the effects of these activities ultimately have on the anchovy fishery, through this nursery function, our study aims to contribute to the process of making the ecosystem approach operational in the Gulf of Cadiz

Performance of bacterial nanocellulose packaging film functionalised in situ with zinc oxide: migration onto chicken skin and antimicrobial activity

Zinc oxide nanoparticles (ZnO) are cost-effective antimicrobial agents with great potential for the active packaging industry. Bacterial NanoCellulose (BNC) features a porous fibre network, with high absorption capacity, flexible and with good mechanical properties, suitable as a carrier of active agents. In this work, BNCZnO films were developed and optimized regarding the particle size and ZnO concentration. The NaOH dropwise addition to BNC membranes immersed in Zn(CH3COO)2-PVOH enabled the production of ZnO nanoparticles with an z-average of 144 nm and a low polydispersity index. High ZnO incorporation (∼27%mZn/mBNCZnO) was obtained, with uniform distribution all over the BNC membranes. These composites were then characterized and evaluated for Zn migration using food simulants (10%, 20%, and 50% ethanol) with results lower than the limit. Migration into chicken skin, as a real food model, was low at 4 °C but exceeded the migration limit at 10 and 22 °C. Zn migration was also found to be temperature and pH dependent. When applied to chicken skin, BNCZnO was effective against E. coli, Salmonella (0.5–1.0 log reduction), and Campylobacter spp. (2.0 log reduction), indicating its potential for active packaging applications.info:eu-repo/semantics/publishedVersio

Notícias da Actividade Cultural. III Seminário de Arqueologia do Noroeste Peninsular. Estudo dos depósitos e indústrias quaternárias nos vales fluviais do Minho. Notícia sumária sobre as investigações em curso.

94 Jan.-Dez. 1984, p. 339-344

Urban landscape and infection risk in free-roaming cats

Altres ajuts: Fundação para a Ciência e a Tecnologia (FCT) CEECIND/01428/2018. FEDER UID/AMB/50017/2019Despite public concern on the role of free-roaming cats as reservoirs of zoonotic agents, little is known about the influence of urban and peri-urban landscapes on the exposure risk. We evaluated the seroprevalence of three zoonotic agents (Chlamydia felis, Coxiella burnetii and Toxoplasma gondii) in domestic cats (Felis catus). Two hundred and ninety-one free-roaming cats were trapped in Murcia municipality (Southeast Spain), and their sera were tested for specific antibodies against T. gondii using a modified agglutination test (MAT), and for C. felis, C. burnetii and feline immunodeficiency virus (FIV) antibodies with ELISA technique. Pathogen seroprevalence at 95% CI was calculated for each sex and age category (up to and over 12 months) and compared with a chi-squared test. The role of human population density and urban landscape characteristics on the risk of pathogen exposure in the cat population was explored using generalized linear models. Seropositivity against a single pathogen was found in 60% of the cats, while 19% was seropositive for two or three pathogens. Seroprevalence of C. felis was 8% (CI: 5-11), 37% (CI: 31-42) for C. burnetii and 42% (CI: 36-47) for T. gondii. In addition to these three pathogens, FIV seropositivity was low (1%, CI: −0.1 to 2) and adult cats were more likely to be seropositive to C. burnetii than young individuals (OR: 2.3, CI: 1.2-4.2). No sex or age class differences in seroprevalence were observed for the rest of the pathogens. Seropositivity was correlated with water surface areas for C. felis, and not with crop areas. Coxiella burnetii seropositivity was correlated with the percentage of urban areas (continuous with only buildings and discontinuous, that include buildings, parks, and pedestrian and urban green areas), human population size and peri-urban areas with shrubs, and not correlated with other agricultural landscapes (orchards and crop areas). However, the seroprevalence of T. gondii was only associated with agricultural landscapes such as orchards. The detection of hotspot areas of high pathogen exposure risk is the basis for municipal services to implement surveillance and risk factor control campaigns in specific-risk areas, including (a) efficient health management of urban cat colonies by geographical location, population census and health status monitoring of the components of each cat colony, (b) improvement of hygiene and sanitary conditions at the feeding points of the cat colony and (c) free-roaming cat trapping for health monitoring and, in the long term, to know the evolution of the health status of their populations

Volatiles of the Inflorescences of the Madeiran Orchids, Goodyera macrophylla Lowe and Gennaria diphylla (Link) Parl. and Their Role in Pollination

Goodyera macrophylla, considered a rare endemic, and Gennaria diphylla are two native terrestrial Orchidaceae species that can be found mainly in Madeiran Laurisilva. The volatile compounds contributing to the floral scent of these two Madeiran orchids were analysed and compared for the first time. The volatiles, isolated by distillation-extraction in a Likens-Nickersontype apparatus, and those extracted by headspace sorption, were analysed by GC and GC-MS. The main volatile components isolated by distillation-extraction were γ-terpinene (13%) and n-nonanal (11%) in G. macrophylla and n-octacosane (19%) and n-heptacosane (13%) in G. diphylla. The main volatile components isolated by headspace sorption were p-cymene (21%), α-pinene (15%) and linalool (14%) in G. macrophylla and cis-arbusculone (28%) and lilac alcohol (26%) in G. diphylla. The importance of the volatiles in the pollination of these orchids is discussed.Portuguese Foundation for the Science and Technology (FCT, Fundação para a Ciência e Tecnologia) has sponsored this work, through the Centre of Macaronesian Studies (CEM). The authors are also grateful to the Madeiran Centre of Science and Technology (CITMA) for financial support.info:eu-repo/semantics/publishedVersio

Alguns dados referentes ao estudo parasitológico e anatomopatológico de duas linhagens de Schistosoma mansoni Sambon, 1907

An experiment was carried out in order to determine differences in the pathology of two S. mansoni strains, one from the state of Minas Gerais (Belo Horizonte) and the other from the State of S. Paulo (S. José dos Campos), Brazil. Mice were infected with both strains under experimental conditions and the comparative study of these animals showed significant differences as regards pathology of the tissue lesions. The Belo Horizonte strain showed a higher level of pathogenicity when compared to the S. José dos Campos one.Foi estudada a ação patogênica das linhagens de Schistosoma mansoni dos municípios de Belo Horizonte, MG e de São José dos Campos, SP (Brasil) observando maior capacidade patogênica da linhagem do primeiro, nas condições da experiência

The development of an excellence model integrating the Shingo model and sustainability

Companies are continuously looking to improve their production systems using excellence models, with lean thinking, the Shingo model, six sigma and lean six sigma being the most comprehensive and applied. It is expected that the initial focus for the survival of companies is their economic profitability, but when economic needs are met, the next step is to achieve operational excellence. For this, in addition to economic objectives, it is necessary to include social and environmental objectives, i.e., the other two pillars of sustainability. This study aims to propose a conceptual model identifying the tools that can help achieve the desired results in the three pillars of sustainability aligned with operational excellence. The design of the conceptual model was based on a bibliometric analysis of the literature that relates the concepts of lean thinking, six sigma, lean six sigma and the Shingo model. The Web of Science was the platform selected for the collection of data, and the timeframe considered was 2010 to 2021. A total of 125 articles were analyzed using the VosViewer software, through which it was possible to analyze different topics of study related to the literature. The bibliometric analysis allowed for the identification of the temporal distribution of publications, the categorization of topics, different areas of application and the importance of the tools used in different practical cases. This study points out that companies have at their disposal several tools to achieve economic objectives. On the other hand, there is a set of more restricted tools that are used to meet the objectives of the social and environmental pillars. Future research should focus on identifying tools that meet social and environmental goals in order to strengthen these pillars that are essential for operational excellence and for the sustainability of companies.The work of the author Vanda Lima is supported by national funds, through the FCT-Portuguese Foundation for Science and Technology under the project UIDB/04728/2020