The 5'-3' exoribonuclease Pacman (Xrn1) regulates expression of the heat shock protein Hsp67Bc and the microRNA miR-277-3p in Drosophila wing imaginal discs

Pacman/Xrn1 is a highly conserved exoribonuclease known to play a critical role in gene regulatory events such as control of mRNA stability, RNA interference and regulation via miRNAs. Although Pacman has been well studied in Drosophila tissue culture cells, the biologically relevant cellular pathways controlled by Pacman in natural tissues are unknown. This study shows that a hypomorphic mutation in pacman (pcm5) results in smaller wing imaginal discs. These tissues, found in the larva, are known to grow and differentiate to form wing and thorax structures in the adult fly. Using microarray analysis, followed by quantitative RT-PCR, we show that eight mRNAs were increased in level by >2 fold in the pcm5 mutant wing discs compared to the control. The levels of pre mRNAs were tested for five of these mRNAs; four did not increase in the pcm5 mutant, showing that they are regulated at the post-transcriptional level and therefore could be directly affected by Pacman. These transcripts include one that encodes the heat-shock protein Hsp67Bc, which is upregulated 11.9-fold at the post-transcriptional level and 2.3-fold at the protein level. One miRNA, miR-277-3p, is 5.6-fold downregulated at the post-transcriptional level in mutant discs, suggesting that Pacman affects its processing in this tissue. Together, these data show that a relatively small number of mRNAs and miRNAs substantially change in abundance in pacman mutant wing imaginal discs. Since Hsp67Bc is known to regulate autophagy and protein synthesis, it is possible that Pacman may control the growth of wing imaginal discs by regulating these processes

Accurate discretization of advection-diffusion equations

We present an exact mathematical transformation which converts a wide class of advection-diffusion equations into a form allowing simple and direct spatial discretization in all dimensions, and thus the construction of accurate and more efficient numerical algorithms. These discretized forms can also be viewed as master equations which provides an alternative mesoscopic interpretation of advection-diffusion processes in terms of diffusion with spatially varying hopping rates

Respirometric assessment of bacterial kinetics in algae-bacteria and activated sludge processes

Algae-bacteria (AB) consortia can be exploited for effective wastewater treatment, based on photosynthetic oxygenation to reduce energy requirements for aeration. While algal kinetics have been extensively evaluated, bacterial kinetics in AB systems are still based on parameters taken from the activated sludge models, lacking an experimental validation for AB consortia. A respirometric procedure was therefore proposed, to estimate bacterial kinetics in both activated sludge and AB, under different conditions of temperature, pH, dissolved oxygen, and substrate availability. Bacterial activities were differently influenced by operational/environmental conditions, suggesting that the adoption of typical activated sludge parameters could be inadequate for AB modelling. Indeed, respirometric results show that bacteria in AB consortia were adapted to a wider range of conditions, compared to activated sludge, confirming that a dedicated calibration of bacterial kinetics is essential for effectively modelling AB systems, and respirometry was proven to be a powerful and reliable tool to this purpose

Prevalencia del síndrome metabólico en población laboral española: registro MESYAS

Introducción y objetivos. Estudiar la prevalencia del síndrome metabólico (SM) en la población laboral activa española y analizar sus diferencias según las categorías laborales. Sujetos y método. Se recogieron los datos de 7.256 trabajadores activos (un 82,4% varones), con una edad media de 45,4 ± 9,8 años, empleados en una factoría de coches y unos grandes almacenes. El diagnóstico del SM se realizó mediante los criterios modificados del ATP-III (se utilizó el índice de masa corporal en lugar del perímetro abdominal). Resultados. La prevalencia bruta del SM fue del 10,2%. Ajustada por edad y sexo en una población plana (20-60 años) fue del 5,8% (intervalo de confianza [IC] del 95%, 4,1-7,6%), significativamente más alta en varones que en mujeres (el 8,7%; IC del 95%, 7,3-10,0 frente al 3,0%; IC del 95%, 0,8-5,1). Todos los componentes del SM fueron significativamente más prevalentes en varones, excepto las concentraciones de lipoproteínas de alta densidad, que fueron más bajas. La prevalencia aumentó con la edad y el sexo masculino (odds ratio [OR] = 1,7), la obesidad (OR = 9,6), la hipertensión (OR = 3,4) y la diabetes (OR = 15,4). Los trabajadores manuales presentaron la mayor prevalencia de SM (11,8%), seguidos por EPIDEMIOLOGÍA Y PREVENCIÓN Prevalencia del síndrome metabólico en población laboral española: registro MESYAS Eduardo Alegríaa, Alberto Corderoa, Martín Laclaustrab, Alberto Grimac, Montserrat Leónb, José A. Casasnovasb, Emilio Luengod, Alfonso del Ríob e Ignacio Ferreirab, en representación de los investigadores del registro MESYAS* aDepartamento de Cardiología. Clínica Universitaria de Navarra. Pamplona. Navarra. España. bUnidad de Investigación Cardiovascular. Hospital Clínico Universitario. Zaragoza. España. cServicio de Cardiología Preventiva. Asepeyo. Valencia. España. dServicio de Cardiología. Hospital Militar. Zaragoza. España. *Al final del artículo se relacionan los miembros del equipo de investigación MESYAS. Martín Laclaustra está contratado como investigador en el Instituto Aragonés de Ciencias de la Salud dentro del programa de ayudas a contratos para investigadores que han finalizado su formación médica especializada del Instituto de Salud Carlos III. El registro MESYAS cuenta con una beca de la Sociedad Española de Cardiología (Sevilla, 2003) y la Sección de Cardiología Preventiva y Rehabilitadora. Correspondencia: Dr. E. Alegría Ezquerra. Departamento de Cardiología. Clínica Universitaria de Navarra. Avda. Pío XII, 36. 31008 Pamplona. Navarra. España. Correo electrónico: [email protected] Recibido el 5 de octubre de 2004. Aceptado para su publicación el 18 de marzo de 2005. los trabajadores de oficina (9,3%) y los directivos (7,7%) (gradiente social inverso). Los trabajadores manuales tienen un riesgo superior de presentar SM, con independencia de la edad y el sexo (OR = 1,3); este efecto parece depender de las concentraciones de triglicéridos. Conclusiones. Uno de cada 10 trabajadores activos tiene SM; la prevalencia aumenta con la edad y el sexo masculino. La obesidad y la diabetes suponen gran incremento de la prevalencia. Los trabajadores manuales son el colectivo con mayor prevalencia

Utilization of centrate for the outdoor production of marine microalgae at pilot-scale in flat-panel photobioreactors

The outdoor production of marine microalgae biomass in pilot scale flat panels photobioreactors, under not sterile conditions and using centrate as nutrients source, was studied. Experiments were performed modifying the centrate percentage, dilution rate and orientation of the photobioreactors. The strain Geitlerinema sp. was that one prevailing independently of the culture conditions. The higher productivity of 47.7 gbiomass·m-2·day-1 dry weight and photosynthetic efficiency of 2.8%, was achieved when using 20% centrate and a dilution rate of 0.3 day-1, whatever the orientation of the reactor, maximal nutrient removal capacities of 82%, 85% and 100% for carbon, nitrogen and phosphorus being obtained. Under non-optimal conditions up to 80% of the nitrogen and 60% of the phosphorus were lost by stripping and precipitation, respectively. Carbohydrates was the major component of the biomass followed by proteins and lipids. These results support the possibility to produce microalgae biomass below 0.59 €/kg, useful to produce biofertilizers and animal feed

Parameter estimation for biochemical reaction networks using Wasserstein distances

We present a method for estimating parameters in stochastic models of biochemical reaction networks by fitting steady-state distributions using Wasserstein distances. We simulate a reaction network at different parameter settings and train a Gaussian process to learn the Wasserstein distance between observations and the simulator output for all parameters. We then use Bayesian optimization to find parameters minimizing this distance based on the trained Gaussian process. The effectiveness of our method is demonstrated on the three-stage model of gene expression and a genetic feedback loop for which moment-based methods are known to perform poorly. Our method is applicable to any simulator model of stochastic reaction networks, including Brownian Dynamics.Comment: 22 pages, 8 figures. Slight modifications/additions to the text; added new section (Section 4.4) and Appendi

A transdisciplinary and community-driven database to unravel subduction zone initiation

Subduction zones are pivotal for the recycling of Earth’s outer layer into its interior. However, the conditions under which new subduction zones initiate are enigmatic. Here, we constructed a transdisciplinary database featuring detailed analysis of more than a dozen documented subduction zone initiation events from the last hundred million years. Our initial findings reveal that horizontally forced subduction zone initiation is dominant over the last 100 Ma, and that most initiation events are proximal to pre-existing subduction zones. The SZI Database is expandable to facilitate access to the most current understanding of subduction zone initiation as research progresses, providing a community platform that establishes a common language to sharpen discussion across the Earth Science community

Rate Equations for Graphs

In this paper, we combine ideas from two different scientific traditions: 1) graph transformation systems (GTSs) stemming from the theory of formal languages and concurrency, and 2) mean field approximations (MFAs), a collection of approximation techniques ubiquitous in the study of complex dynamics. Using existing tools from algebraic graph rewriting, as well as new ones, we build a framework which generates rate equations for stochastic GTSs and from which one can derive MFAs of any order (no longer limited to the humanly computable). The procedure for deriving rate equations and their approximations can be automated. An implementation and example models are available online at https://rhz.github.io/fragger. We apply our techniques and tools to derive an expression for the mean velocity of a two-legged walker protein on DNA.Comment: to be presented at the 18th International Conference on Computational Methods in Systems Biology (CMSB 2020

Placebo-controlled trial of nimodipine in the treatment of acute ischemic cerebral infarction

Nimodipine is a 1,4-dihydropyridine derivative that shows a preferential cerebrovascular activity in experimental animals. Clinical data suggest that nimodipine has a beneficial effect on the neurologic outcome of patients suffering an acute ischemic stroke. Our double-blind placebo-controlled multicenter trial was designed to assess the effects of oral nimodipine on the mortality rate and neurologic outcome of patients with an acute ischemic stroke. One hundred sixty-four patients were randomly allocated to receive either nimodipine tablets (30 mg q.i.d.) or identical placebo tablets for 28 days. Treatment was always started less than or equal to 48 hours after the acute event. The Mathew Scale, slightly modified by Gelmers et al, was used for neurologic assessment. Mortality rate and neurologic outcome after 28 days were used as evaluation criteria. We considered 123 patients to be valid for the analysis of efficacy. Mortality rates did not differ significantly between groups. Neurologic outcome after 28 days of therapy did not differ between groups. However, when only those patients most likely to benefit from any intervention (Mathew Scale sum score of less than or equal to 65 at baseline) were analyzed separately in post hoc-defined subgroups, the nimodipine-treated subgroups showed a significantly better neurologic outcome. This result suggests that some patients with acute ischemic stroke will benefit from treatment with nimodipine tablets