2,522 research outputs found
Evaluation of sludge from paper recycling as bedding material for broilers
Several materials have been used as bedding substrates in broiler production. In this work, the sludge from paper recycling was tested for its potential use as litter material and was compared with wood shavings. Moisture content, apparent density, and water-holding capacity were measured and characterized in both materials. Later, 192 male broiler chickens were distributed among 16 experimental pens, 8 of which contained wood shavings as bedding material and 8 of which contained the sludge. growth rate, consumption, tonic immobility, gait score, breast lesions, foot pad dermatitis, hock burn, tibial dyschondroplasia, and metatarsal thickness were determined in the birds. Although the moisture content of the sludge was high, it decreased strongly after 7 d of drying, reaching lower values than those of wood shavings. In general, few differences were found between the materials in terms of bird performance and welfare and only the incidence of hock burn was higher in the sludge than in the wood shavings. Although further research is needed, sludge from paper recycling is a possible alternative to traditional bedding materials because it achieves most of the requirements for broiler bedding materials and does not show negative effects on the birds
The influence of glacial cover on riverine silicon and iron exports in Chilean Patagonia
Glaciated environments have been highlighted as important sources of bioavailable nutrients, with inputs of glacial meltwater potentially influencing productivity in downstream ecosystems. However, it is currently unclear how riverine nutrient concentrations vary across a spectrum of glacial cover, making it challenging to accurately predict how terrestrial fluxes will change with continued glacial retreat. Using 40 rivers in Chilean Patagonia as a unique natural laboratory, we investigate how glacial cover affects riverine Si and Fe concentrations, and infer how exports of these bioessential nutrients may change in the future. Dissolved Si (as silicic acid) and soluble Fe (0.45 mu m) phases of both Si and Fe, which are not typically accounted for in terrestrial nutrient budgets but can dominate riverine exports. Dissolved Si and soluble Fe yield estimates showed no trend with glacial cover, suggesting no significant change in total exports with continued glacial retreat. However, yields of colloidal-nanoparticulate and reactive sediment-bound Si and Fe were an order of magnitude greater in highly glaciated catchments and showed significant positive correlations with glacial cover. As such, regional-scale exports of these phases are likely to decrease as glacial cover disappears across Chilean Patagonia, with potential implications for downstream ecosystems
DRD1 signaling modulates TrkB turnover and BDNF sensitivity in direct pathway striatal medium spiny neurons
Disturbed motor control is a hallmark of Parkinson's disease (PD). Cortico-striatal synapses play a central role in motor learning and adaption, and brain-derived neurotrophic factor (BDNF) from cortico-striatal afferents modulates their plasticity via TrkB in striatal medium spiny projection neurons (SPNs). We studied the role of dopamine in modulating the sensitivity of direct pathway SPNs (dSPNs) to BDNF in cultures of fluorescence-activated cell sorting (FACS)-enriched D1-expressing SPNs and 6-hydroxydopamine (6-OHDA)-treated rats. DRD1 activation causes enhanced TrkB translocation to the cell surface and increased sensitivity for BDNF. In contrast, dopamine depletion in cultured dSPN neurons, 6-OHDA-treated rats, and postmortem brain of patients with PD reduces BDNF responsiveness and causes formation of intracellular TrkB clusters. These clusters associate with sortilin related VPS10 domain containing receptor 2 (SORCS-2) in multivesicular-like structures, which apparently protects them from lysosomal degradation. Thus, impaired TrkB processing might contribute to disturbed motor function in PD.This work was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) project 424778381 (TRR295, A05, A06, and A01), project SE697/7-1, and project 218894895 (INST93/761-1FUGG). R.L.M.was supported by the Alexander von Humboldt-Stiftung. V.P. and C.S.were supported by GRK2581 (P6) SPHINGOINF of the DFG.Work in the lab of R.M. was supported by grant PID2019-111693RB-100 from MICIN/AEI/10.13039/501100011033, the European Union’s Horizon 2020 research and innovation program, AND-PD (grant 84800),Next Generation EU/PRTR (MICIN/CSIC/PTI+NeuroAging), and CIBERNED, Instituto de Salud Carlos III. The graphical abstract was created with BioRender.com. We thank Drs.James Surmeier, Moses Chao, and Esther Asan for critical comments and suggestions
Aurora kinase A drives the evolution of resistance to third-generation EGFR inhibitors in lung cancer.
Although targeted therapies often elicit profound initial patient responses, these effects are transient due to residual disease leading to acquired resistance. How tumors transition between drug responsiveness, tolerance and resistance, especially in the absence of preexisting subclones, remains unclear. In epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma cells, we demonstrate that residual disease and acquired resistance in response to EGFR inhibitors requires Aurora kinase A (AURKA) activity. Nongenetic resistance through the activation of AURKA by its coactivator TPX2 emerges in response to chronic EGFR inhibition where it mitigates drug-induced apoptosis. Aurora kinase inhibitors suppress this adaptive survival program, increasing the magnitude and duration of EGFR inhibitor response in preclinical models. Treatment-induced activation of AURKA is associated with resistance to EGFR inhibitors in vitro, in vivo and in most individuals with EGFR-mutant lung adenocarcinoma. These findings delineate a molecular path whereby drug resistance emerges from drug-tolerant cells and unveils a synthetic lethal strategy for enhancing responses to EGFR inhibitors by suppressing AURKA-driven residual disease and acquired resistance
Toward Engineering Biosystems With Emergent Collective Functions
Many complex behaviors in biological systems emerge from large populations of interacting molecules or cells, generating functions that go beyond the capabilities of the individual parts. Such collective phenomena are of great interest to bioengineers due to their robustness and scalability. However, engineering emergent collective functions is difficult because they arise as a consequence of complex multi-level feedback, which often spans many length-scales. Here, we present a perspective on how some of these challenges could be overcome by using multi-agent modeling as a design framework within synthetic biology. Using case studies covering the construction of synthetic ecologies to biological computation and synthetic cellularity, we show how multi-agent modeling can capture the core features of complex multi-scale systems and provide novel insights into the underlying mechanisms which guide emergent functionalities across scales. The ability to unravel design rules underpinning these behaviors offers a means to take synthetic biology beyond single molecules or cells and toward the creation of systems with functions that can only emerge from collectives at multiple scales
Toward engineering biosystems with emergent collective functions
Many complex behaviors in biological systems emerge from large populations of interacting molecules or cells, generating functions that go beyond the capabilities of the individual parts. Such collective phenomena are of great interest to bioengineers due to their robustness and scalability. However, engineering emergent collective functions is difficult because they arise as a consequence of complex multi-level feedback, which often spans many length-scales. Here, we present a perspective on how some of these challenges could be overcome by using multi-agent modeling as a design framework within synthetic biology. Using case studies covering the construction of synthetic ecologies to biological computation and synthetic cellularity, we show how multi-agent modeling can capture the core features of complex multi-scale systems and provide novel insights into the underlying mechanisms which guide emergent functionalities across scales. The ability to unravel design rules underpinning these behaviors offers a means to take synthetic biology beyond single molecules or cells and toward the creation of systems with functions that can only emerge from collectives at multiple scales
Factores individuales e institucionales asociados a la vacunación contra el virus de la hepatitis B en recién nacidos de hospitales de Lima y Callao
Introduction. Vaccination against hepatitis B Virus (HBV) in newborns is crucial for the prevention of perinatal transmission. Objective. To determine the individual and institutional factors associated with vaccine for HBV in newborns in the first 12 hours and 24 hours of life. Methods. A cross-sectional, multicenter-design study was conducted in high level public and private hospitals in Lima Metropolitana and Callao. Information on vaccination was obtained through consultations with parents and review of health service reports. Individual variables of the newborns and their mothers were obtained from the medical records of the newborns. Institutional data were collected from immediate care records and from health personnel responsible for the immunization program. Results. The study was conducted in 10 health facilities, including 777 newborns. In the multilevel analysis, the longest care time in the vaccination service was favorable for vaccination within 12 hours of life (PR: 1,0; 95% CI: 0,9995-1,01); while for vaccination within 24 hours of life was favorable the greater number of nursing personnel (RP: 1,02; IC95%: 1,01-1,03) and unfavorable the greater number of deliveries per day in the institution (RP: 0,99; IC95%: 0,99-0,997). No individual factors related to vaccination were identified. Conclusions. Institutional factors, such as length of care, number of nursing staff, and number of deliveries, were associated with newborn HBV vaccination. Improvement strategies are required, such as the introduction of vaccination in the immediate care of the newborn for the prevention of perinatal transmission of HBV.Introducción. La vacunación contra el virus de la hepatitis B (VHB) en recién nacidos es crucial para la prevención de la transmisión perinatal. Objetivo. Determinar factores individuales e institucionales asociados a la vacunación contra el VHB en las 12 y 24 primeras horas de vida. Métodos. Se diseñó un estudio transversal y multicéntrico. Los datos sobre la vacunación fueron recogidos de los padres y de la revisión de reportes. Los datos de los variables individuales de los recién nacidos y madres fueron recogidos de las historias clínicas. Los datos institucionales fueron recogidos de registros de atención inmediata y directamente del personal de inmunizaciones. Resultados. Se incluyó 777 recién nacidos en 10 establecimientos. En el análisis multinivel resultó favorable a la vacunación en las primeras 12 horas, el mayor tiempo de atención en los servicios de inmunizaciones (RP: 1,0; IC95%: 0,99 - 1,01). Para la vacunación dentro de las 24 horas de vida fue favorable la mayor cantidad de personal de enfermería en los servicios de vacunación (RP: 1,02; IC95%: 1,01 - 1,03) y desfavorable la mayor cantidad de partos al día de los establecimientos (RP: 0,99; IC95%: 0,99 - 0,997). No se identificó factores individuales. Conclusión. Factores institucionales, como el tiempo de atención, la cantidad de personal de enfermería y la cantidad de partos, estuvieron asociados con la vacunación contra el VHB en recién nacidos. Se requiere estrategias de mejora como la introducción de la vacunación en la atención inmediata del neonato para la prevención de la transmisión perinatal del VHB
A Study of Time-Dependent CP-Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon(4S)
We present a measurement of time-dependent CP-violating asymmetries in
neutral B meson decays collected with the BABAR detector at the PEP-II
asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data
sample consists of 29.7 recorded at the
resonance and 3.9 off-resonance. One of the neutral B mesons,
which are produced in pairs at the , is fully reconstructed in
the CP decay modes , , , () and , or in flavor-eigenstate
modes involving and (). The flavor of the other neutral B meson is tagged at the time of
its decay, mainly with the charge of identified leptons and kaons. The proper
time elapsed between the decays is determined by measuring the distance between
the decay vertices. A maximum-likelihood fit to this flavor eigenstate sample
finds . The value of the asymmetry amplitude is determined from
a simultaneous maximum-likelihood fit to the time-difference distribution of
the flavor-eigenstate sample and about 642 tagged decays in the
CP-eigenstate modes. We find , demonstrating that CP violation exists in the neutral B meson
system. (abridged)Comment: 58 pages, 35 figures, submitted to Physical Review
High prevalence and two dominant host-specific genotypes of Coxiella burnetii in U.S. milk
BackgroundCoxiella burnetii causes Q fever in humans and Coxiellosis in animals; symptoms range from general malaise to fever, pneumonia, endocarditis and death. Livestock are a significant source of human infection as they shed C. burnetii cells in birth tissues, milk, urine and feces. Although prevalence of C. burnetii is high, few Q fever cases are reported in the U.S. and we have a limited understanding of their connectedness due to difficulties in genotyping. Here, we develop canonical SNP genotyping assays to evaluate spatial and temporal relationships among C. burnetii environmental samples and compare them across studies. Given the genotypic diversity of historical collections, we hypothesized that the current enzootic of Coxiellosis is caused by multiple circulating genotypes. We collected A) 23 milk samples from a single bovine herd, B) 134 commercial bovine and caprine milk samples from across the U.S., and C) 400 bovine and caprine samples from six milk processing plants over three years.ResultsWe detected C. burnetii DNA in 96% of samples with no variance over time. We genotyped 88.5% of positive samples; bovine milk contained only a single genotype (ST20) and caprine milk was dominated by a second type (mostly ST8).ConclusionsThe high prevalence and lack of genotypic diversity is consistent with a model of rapid spread and persistence. The segregation of genotypes between host species is indicative of species-specific adaptations or dissemination barriers and may offer insights into the relative lack of human cases and characterizing genotypes
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