258 research outputs found

    Influence of Intensive Animal Breeding to the Appearance of Infectious Diseases (Zoonoses)

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    Intensive animal breeding and production is based on farm breeding of animals which represents a major source of raw material for food production. Preserving health of animals requires a good practice during breeding, appropriate feeding and watering, adequate control of pests and wild animals. Animal breeding and production of food of animal origin requires significant engagement of veterinary services within the frame of epizootiological, epidemiological, veterinary and sanitary surveillance. Farm manner of cattle breeding can represent a danger of air, water and ground contamination. In the farms situated in a small space, overcrowded with animals there are ideal conditions for the appearance and spreading of causative agent of infectious diseases (prions, viruses, rickettsiae, chlamydia, bacteria, parasites and fungi), which can be transmitted also to humans and wild animals. From the aspect of public health, special attention should be given to the farms with large number of animals and farms with intensive breeding conditions. This is especially important in pig and poultry breeding, where moderate or high prevalence of infections such as salmonellosis and campylobacteriosis are often present, regardless of the fact that the level of clinical illness caused by these infections is relatively low. Intensive production in animal husbandry leads to increased animal waste, and the richest source of infectious agents represents animal feces

    Role of active layer in the performance of aromatic and semi-aromatic nanofiltration membranes for water purification

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    Nanofiltration (NF) membranes that differ in molecular weight cut off (MWCO), active layer chemistry, porosity and pore size distribution are available for different applications. These membranes are typically made of three layers: the active layer, polysulfone support layer and a fabric for mechanical strength. It has been proven that the performance of an NF membrane is almost entirely dependent on the active layer, which can be made of polyamide, polypiperazine amide, cellulose acetate or polyethersulfone. Polyamide, which is considered fully aromatic (FA) and polypiperazine, which is considered semi-aromatic (SA), are the most commonly used active layers in NF membranes for water treatment. Several studies evaluated commercially available NF membranes for ion rejection, effect of pH, temperature, pressure but very few have attempted to explain their performance based on the membrane active layer chemistry. This study is focused on understanding the difference in performance between fully aromatic (FA) and semi-aromatic (SA) membranes for the removal of typical ions of concern in water purification. Four commercially available membranes, two each of FA and SA types were selected for this study. Fourier Transform Infrared (FTIR) spectroscopy was used to substantiate that the selected membranes are truly representative of FA and SA membrane type without any coating or other surface modifications. Membrane performance was analyzed in terms of ion rejection and permeate flux. Membrane volume charge densities as a function of electrolyte concentration were analyzed by measuring their zeta potential as function of pH and electrolyte composition and concentration. The membrane mean pore size was determined using the membrane potential technique [1]. Membrane potential data were analyzed using the steric, electric and dielectric exclusion (SEDE) model [2]. Also, SEDE model was used to calculate the dielectric constants for different electrolyte composition and compare them for FA and SA membranes. The ion rejection and permeate flux for all four membranes was studied for different feed composition using a SEPA cross flow NF cell at a fixed transmembrane pressure and temperature. The feed composition was selected such that it is representative of the acid mine drainage (AMD) typically found in Pennsylvania, which is characterized by high sulfate concentration and low pH. The resulting ion rejection and permeate flux were compared for the four membranes with goal of understanding the difference in the performance of FA and SA membranes as a function of the active layer chemistry. The experimental results indicate that the rejection of sulfate was in all cases above 98% but the rejection of the counterions was significantly better for the fully aromatic membranes. Major disparity was observed in the rejection of sodium and chloride ions between FA and SA membranes even when they had the same MWCO’s. This disparity was studied in terms of the electronegativity of the four membranes and the results will be presented at the conference. 1. Escoda, A., et al., Determining the Dielectric Constant inside Pores of Nanofiltration Membranes from Membrane Potential Measurements. Langmuir, 2010. 26(18): p. 14628-14635. 2. Szymczyk, A. and P. Fievet, Investigating transport properties of nanofiltration membranes by means of a steric, electric and dielectric exclusion model. Journal of Membrane Science, 2005. 252(1–2): p. 77-88

    Silicon resonant microcantilevers for absolute pressure measurement

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    This work is focused on the developing of silicon resonant microcantilevers for the measurement of the absolute pressure. The microcantilevers have been fabricated with a two-mask bulk micromachining process. The variation in resonance response of microcantilevers was investigated as a function of pressure 10−1-105 Pa, both in terms of resonance frequency and quality factor. A theoretical description of the resonating microstructure is given according to different molecular and viscous regimes. Also a brief discussion on the different quality factors contributions is presented. Theoretical and experimental data show a very satisfying agreement. The microstructure behavior demonstrates a certain sensitivity over a six decade range and the potential evolution of an absolute pressure sensor working in the same rang

    Repeat-sequence turnover shifts fundamentally in species with large genomes

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    Given the 2,400-fold range of genome sizes (0.06–148.9 Gbp (gigabase pair)) of seed plants (angiosperms and gymnosperms) with a broadly similar gene content (amounting to approximately 0.03 Gbp), the repeat-sequence content of the genome might be expected to increase with genome size, resulting in the largest genomes consisting almost entirely of repetitive sequences. Here we test this prediction, using the same bioinformatic approach for 101 species to ensure consistency in what constitutes a repeat. We reveal a fundamental change in repeat turnover in genomes above around 10 Gbp, such that species with the largest genomes are only about 55% repetitive. Given that genome size influences many plant traits, habits and life strategies, this fundamental shift in repeat dynamics is likely to affect the evolutionary trajectory of species lineages.We thank Natural Environment Research Council (NE/G020256/1), the Czech Academy of Sciences (RVO:60077344) and RamĂłn y Cajal Fellowship (RYC-2017-2274) funded by the Ministerio de Ciencia y TecnologĂ­a (Gobierno de España) for support. We also thank Natural Environment Research Council for funding a studentship to S.D. and the China Scholarship Council for funding W.W.Abstract Main Methods Data availability Code availability References Acknowledgements Author information Ethics declarations Additional information Extended data Supplementary information Rights and permissions About this article Further readin

    Electrotransfer of Single-Stranded or Double-Stranded DNA Induces Complete Regression of Palpable B16.F10 Mouse Melanomas

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    Enhanced tumor delivery of plasmid DNA with electric pulses in vivo has been confirmed in many preclinical models. Intratumor electrotransfer of plasmids encoding therapeutic molecules has reached Phase II clinical trials. In multiple preclinical studies, a reduction in tumor growth, increased survival or complete tumor regression have been observed in control groups in which vector or backbone plasmid DNA electrotransfer was performed. This study explores factors that could produce this antitumor effect. The specific electrotransfer pulse protocol employed significantly potentiated the regression. Tumor regression was observed after delivery of single-stranded or double-stranded DNA with or without CpG motifs in both immunocompetent and immunodeficient mice, indicating the involvement of the innate immune system in response to DNA. In conclusion, this study demonstrated that the observed antitumor effects are not due to a single factor, but to a combination of factors

    Inertio-elastic focusing of bioparticles in microchannels at high throughput

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    Controlled manipulation of particles from very large volumes of fluid at high throughput is critical for many biomedical, environmental and industrial applications. One promising approach is to use microfluidic technologies that rely on fluid inertia or elasticity to drive lateral migration of particles to stable equilibrium positions in a microchannel. Here, we report on a hydrodynamic approach that enables deterministic focusing of beads, mammalian cells and anisotropic hydrogel particles in a microchannel at extremely high flow rates. We show that on addition of micromolar concentrations of hyaluronic acid, the resulting fluid viscoelasticity can be used to control the focal position of particles at Reynolds numbers up to Re≈10,000 with corresponding flow rates and particle velocities up to 50 ml min[superscript −1] and 130 m s[superscript −1]. This study explores a previously unattained regime of inertio-elastic fluid flow and demonstrates bioparticle focusing at flow rates that are the highest yet achieved.National Institute for Biomedical Imaging and Bioengineering (U.S.) (P41 BioMicroElectroMechanical Systems Resource Center)National Institute for Biomedical Imaging and Bioengineering (U.S.) (P41 EB002503)National Science Foundation (U.S.). Graduate Research FellowshipUnited States. Army Research Office (Institute for Collaborative Biotechnologies Grant W911NF-09-0001

    Genomic testing for children with interstitial and diffuse lung disease (chILD): Parent satisfaction, understanding and health-related quality of life

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    Objective Research is needed to determine best practice for genomic testing in the context of child interstitial or diffuse lung disease (chILD). We explored parent’s and child’s health-related quality of life (HRQoL), parents’ perceived understanding of a genomic testing study, satisfaction with information and the study and decisional regret to undertake genomic testing. Methods Parents of children with diagnosed or suspected chILD who were enrolled in a genomic sequencing study were invited to complete questionnaires pretesting (T1) and after receiving the result (T2). Results Parents’ (T1, n=19; T2, n=17) HRQoL was lower than population norms. Study satisfaction (T1) and perceived understanding (T2) were positively correlated (rs=0.68, p=0.014). Satisfaction with information (T1 and T2) and decisional regret (T2) were negatively correlated (T1 rs=−0.71, p=0.01; T2 rs=−0.56, p=0.03). Parents reported wanting more frequent communication with staff throughout the genomic sequencing study, and greater information about the confidentiality of test results. Conclusions Understanding of genomic testing, satisfaction with information and participation and decisional regret are inter-related. Pretest consultations are important and can allow researchers to explain confidentiality of data and the variable turnaround times for receiving a test result. Staff can also update parents when there will be delays to receiving a result.Lauren Kelada, Claire Wakefield, Nada Vidic, David S Armstrong, Bruce Bennetts, Kirsten Boggs, John Christodoulou, Joanne Harrison, Gladys Ho, Nitin Kapur, Suzanna Lindsey-Temple, Tim McDonald, David Mowat, AndrĂ© Schultz, Hiran Selvadurai, Andrew Tai, Adam Jaff
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