The behavior of kinetic parameters in production of pectinase and xylanase by solid-state fermentation

AbstractSolid-state fermentation (SSF) is defined as the growth of microbes without a free-flowing aqueous phase. The feasibility of using a citrus peel for producing pectinase and xylanase via the SSF process by Aspergillus niger F3 was evaluated in a 2kg bioreactor. Different aeration conditions were tested to optimize the pectinase and xylanase production. The best air flow intensity was 1VkgM (volumetric air flow per kilogram of medium), which allowed a sufficient amount of O2 for the microorganism growth producing 265U/g and 65U/g pectinases and xylanases, respectively. A mathematical model was applied to determine the different kinetic parameters related to SSF. The specific growth rate and biomass oxygen yield decreased during fermentation, whereas an increase in the maintenance coefficient for the different employed carbon sources was concurrently observed

Histogenesis and cell differentiation in the retina of Thunnus thynnus: a morphological and immunohistochemical study

This study examines the anatomical development of the visual system of Atlantic bluefin tuna, Thunnus thynnus, during the first 15 days of life at histological level, with emphasis in the immunohistochemical characterization of different cell types. As an altricial fish species, the retina was not developed at hatching. The appearance of eye pigmentation and the transformation of the retina from an undifferentiated neuroblastic layer into a laminated structure occurred during the first two days of life. At 16 days after hatching (DAH), the ganglion cells were arranged in a single row in the central region of the retina and the outer segments of the photoreceptors were morphologically developed. Furthermore, at this age, all the retinal cell types were immunohistochemically characterized. The presence of ganglion cell axons was confirmed with the TUJ1 antibody and the existence of functional synapses in the plexiform layers with antibodies against SV2. Cone opsins were immunostained with antibodies against visinin and CERN-922 immunoreactive rods were also identified. Different subpopulations of amacrine cells were immunostained with antibodies against αTH and PV. Highly GS-immunoreactive Müller cells were also detected at this age. These observations suggested that the T. thynnus retina was fully functional at the end of the second week of life. Basic studies on early morphology of the visual system and larval behaviour are necessary to support applied research on larval rearing. Furthermore, they may have implications for understanding larval ecology in the wild.Versión del edito

Reusing intravaginal progesterone releasing devices for oestrous synchoronization in ewes

In this study, the second use of an intravaginal progesterone-releasing device or controlled intravaginal drug release device (CIDR) was evaluated. After a first use of 11 days, the CIDR was again used for either nine or 12 days with 200 or 300 IU equine chorionic gonadotrophin (eCG) being injected on its removal. Sixty-four ewes were randomly distributed to four treatments (n=16/group): CIDR9+eCG200, CIDR9+eCG300, CIDR12+eCG200, and CIDR12+eCG300. The eCG was administered intramuscularly on withdrawal of the device. Thus, the experiment was a completely randomized design with a 2×2 factorial arrangement of treatments. Oestrus presentation did not differ between treatments (P =0.29). However, with the dose of 200 IU of eCG, oestrus presentation tended to increase (P =0.08). The onset and duration of oestrus, percentage of gestation, and return to oestrus did not differ between treatments (P >0.05). Progesterone concentration in serum was greater (P < 0.05) in ewes treated with CIDR12+eCG300. Prolificacy was greatest (1.44) with the CIDR12+eCG300 treatment and was different (P = 0.001) from the treatments CIDR9+eCG200 (1.21) and CIDR9+eCG300 (1.20), but not from the CIDR12+eCG200 treated ewes (1.31). The CIDR12+eCG300 treatement produced the highest percentage of twin births (45.8%) (P =0.001). Leaving the device in place for 12 days increased (P =0.001) the incidence of twin births. Use of the CIDR for a second time synchronized oestrus in ewes successfully with better fertility being obtained when the device was left in place for 12 days, and 300 IU of eCG was injected on its removal. Key words: gonadotropin, progesterone device, synchronizatio

Analisis and tools for performance prediction

We present an analytical model that extends BSP to cover both oblivious synchronization and group partitioning. There are a few oversimplifications in BSP that make difficult to have accurate predictions. Even if the numbers of individual communication or computation operations in two stages are the same, the actual times for these two stages may differ. These differences are due to the separate nature of the operations or to the particular pattern followed by the messages. Even worse, the assumption that a constant number of machine instructions takes constant time is far from the truth. Current memory hierarchies imply that memory access vary from a few cycles to several thousands. A natural proposal is to associate a different proportionality constant with each basic block, and analogously, to associate different latencies and bandwidths with each “communication block”. Unfortunately, to use this approach implies that the evaluation parameters not only depend on given architecture, but also reflect algorithm characteristics. Such parameter evaluation must be done for every algorithm. This is a heavy task, implying experiment design, timing, statistics, pattern recognition and multi-parameter fitting algorithms. Software support is required. We have developed a compiler that takes as source a C program annotated with complexity formulas and produces as output an instrumented code. The trace files obtained from the execution of the resulting code are analyzed with an interactive interpreter, giving us, among other information, the values of those parameters.Eje: Programación concurrenteRed de Universidades con Carreras en Informática (RedUNCI

Altered functional connectivity in essential tremor

Essential tremor (ET) has been associated with a spectrum of clinical features, with both motor and nonmotor elements, including cognitive deficits. We employed resting-state functional magnetic resonance imaging (fMRI) to assess whether brain networks that might be involved in the pathogenesis of nonmotor manifestations associated with ET are altered, and the relationship between abnormal connectivity and ET severity and neuropsychological function. Resting-state fMRI data in 23 ET patients (12 women and 11 men) and 22 healthy controls (HC) (12 women and 10 men) were analyzed using independent component analysis, in combination with a ‘‘dualregression’’ technique, to identify the group differences of resting-state networks (RSNs) (default mode network [DMN] and executive, frontoparietal, sensorimotor, cerebellar, auditory/language, and visual networks). All participants underwent a neuropsychological and neuroimaging session, where resting-state data were collected. Relative to HC, ET patients showed increased connectivity in RSNs involved in cognitive processes (DMN and frontoparietal networks) and decreased connectivity in the cerebellum and visual networks. Changes in network integrity were associated not only with ET severity (DMN) and ET duration (DMN and left frontoparietal network), but also with cognitive ability.Moreover, in at least 3 networks (DMN and frontoparietal networks), increased connectivity was associated with worse performance on different cognitive domains (attention, executive function, visuospatial ability, verbal memory, visual memory, and language) and depressive symptoms. Further, in the visual network, decreased connectivity was associated with worse performance on visuospatial ability. ET was associated with abnormal brain connectivity in major RSNs that might be involved in both motor and nonmotor symptoms

Patrones de abundancia de la macrofauna asociada a macroalgas marinas a largo de la Península Ibérica

macroalgae were studied on a spatial scale along the Iberian Peninsula. Nineteen stations and four dominant algae were selected (intertidal zone: Corallina elongata and Asparagopsis armata; subtidal zone: Stypocaulon scoparium and Cladostephus spongiosus). Five environmental factors were also considered (seawater temperature, conductivity, dissolved oxygen, turbidity and pH). The Atlantic coast was characterized by lower temperature and conductivity as well as higher values of oxygen and turbidity than the Mediterranean coast. A total of 106274 macrofaunal specimens were sorted and examined (68% arthropods, 27% molluscs, 4% annelids and 1% echinoderms). Crustaceans were the dominant group in all the macroalgae (ca. 80% in C. elongata and A. armata, ca. 50% in S. scoparium and C. spongiosus) followed by molluscs, which were more abundant in the subtidal algae (ca. 40%) than in intertidal ones (ca.10%). Abundance patterns of macrofauna along the Iberian Peninsula were similar in the four studied algae. Most of crustaceans belonged to the order Amphipoda, which showed high densities (>1000 ind/1000 ml algae) along the whole Peninsula; isopods showed the highest abundances in the Atlantic, while tanaids, cumaceans and decapods were more abundant in the Mediterranean. Among molluscs, gasteropods showed highest abundances along the Atlantic coasts, whereas bivalves showed higher densities along the MediterraneanSe llevó a cabo un estudio espacial de los patrones de abundancia y distribución de la macrofauna asociada a macroalgas a lo largo de la Península Ibérica. Se seleccionaron 19 estaciones y 4 algas dominantes (zona intermareal: Corallina elongata y Asparagopsis armata; zona submareal: Stypocaulon scoparium y Cladostephus spongiosus). Se consideraron también cinco variables ambientales (temperatura del agua, conductividad, oxígeno disuelto, turbidez y pH). La costa atlántica se caracterizó por valores más bajos de temperatura y conductividad, y más altos de oxígeno y turbidez. Se examinaron 106274 individuos de la macrofauna (68% artrópodos, 27% moluscos, 4% anélidos y 1% equinodermos). Los crustáceos fueron dominantes en todas las macroalgas (alrededor del 80% en C. elongata y A. armata, y en torno al 50% en S. scoparium y C. spongiosus), seguidos por los moluscos, que fueron más abundantes en el submareal (40%) que en el intermareal (10%). Los patrones de abundancia de la macrofauna a lo largo de la Península Ibérica fueron similares en las cuatro algas estudiadas. La mayoría de los crustáceos pertenecieron al orden Amphipoda, que mostró densidades muy altas (>1000 ind/1000 ml alga) en toda la Península; los isópodos mostraron las mayores densidades en el Atlántico, mientras que los tanaidáceos, cumáceos y decápodos fueron más abundantes en el Mediterráneo. Entre los moluscos, los gasterópodos mostraron abundancias mayores en el Atlántico, mientras que los bivalvos dominaron en el Mediterráneo. Teniendo en cuenta que todas las estaciones seleccionadas no tenían influencia antrópica importante, los patrones de abundancia obtenidos podrían explicarse en base a diferencias naturales en la temperatura del agua, oxígeno, conductividad y turbidez, existiendo un gradiente transicional entre taxones de aguas más cálidas (del norte de Africa y del Mediterráneo) y taxones de aguas más frías (del Mar del Norte y el Ártico)

Tomography of Galactic star-forming regions and spiral arms with the Square Kilometre Array

Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike LicenceVery Long Baseline Interferometry (VLBI) at radio wavelengths can provide astrometry accurate to 10 micro-arcseconds or better (i.e. better than the target GAIA accuracy) without being limited by dust obscuration. This means that unlike GAIA, VLBI can be applied to star-forming regions independently of their internal and line-of-sight extinction. Low-mass young stellar objects (particularly T Tauri stars) are often non-thermal compact radio emitters, ideal for astrometric VLBI radio continuum experiments. Existing observations for nearby regions (e.g. Taurus, Ophiuchus, or Orion) demonstrate that VLBI astrometry of such active T Tauri stars enables the reconstruction of both the regions' 3D structure (through parallax measurements) and their internal kinematics (through proper motions, combined with radial velocities). The extraordinary sensitivity of the SKA telescope will enable similar "tomographic mappings" to be extended to regions located several kpc from Earth, in particular to nearby spiral arm segments. This will have important implications for Galactic science, galactic dynamics and spiral structure theories.Final Published versio

Clostridioides difficile-associated diarrhea in surgical service patients in Mexico

Introduction: Clostridium difficile is the first cause of healthcare-associated diarrhea in developed countries. In recent years the incidence of C. difficile infection (CDI) has increased worldwide. There is not much information on the topic in Mexico, and little is known about the risk factors for the infection in patients that are hospitalized in surgical services. Materials and methods: A case-control study was conducted that compared the epidemiologic findings and risk factors between surgical patients with PCR-confirmed CDI, surgical patients with diarrhea and a negative PCR test, and surgical patients with no diarrhea. The statistical analysis was carried out using the SPSS version 22.0 program. Results: The majority of the surgical patients with CDI belonged to the areas of neurosurgery, cardiac surgery, orthopedics, and general surgery. A total of 53% of the CDI cases were associated with the hypervirulent CD NAP1/027 strain. The presence of mucus in stools (OR: 1.5, p = 0.001), fever (OR: 1.4, p = 0.011), leukocytes in stools (OR: 3.2, p < 0.001), hospitalization within the past twelve weeks (OR: 2.0, p < 0.001), antibiotic use (OR: 1.3, p = 0.023), and ceftriaxone use (OR: 1.4, p = 0.01) were independent risk factors for the development of CDI

Diarrea asociada a Clostridioides difficile en pacientes de servicios quirúrgicos en México

Introducción: Clostridioides difficile (CD) es la primera causa de diarrea asociada al cuidadode salud en los países desarrollados. En los últimos a˜nos, la incidencia de la infección asociadaa CD (ICD) ha aumentado en el ámbito mundial. En México, la información al respecto es escasay se conoce poco sobre los factores de riesgo para esta enfermedad en pacientes hospitalizadosen servicios quirúrgicosMaterial y métodos: Estudio de casos y controles. Se compararon hallazgos epidemiológicos yfactores de riesgo entre pacientes quirúrgicos con ICD confirmada por PCR contra pacientes qui-rúrgicos con diarrea PCR negativa y contra pacientes quirúrgicos sin diarrea. Se realizó análisisestadístico mediante el paquete estadístico SPSS versión 22.0.Resultados: La mayoría de los pacientes quirúrgicos con ICD correspondían a las áreas de neu-rocirugía, cardiocirugía, ortopedia y cirugía general. El 53% de los casos de ICD se asociaron a lacepa hipervirulenta de CD NAP1/027. La presencia de moco en heces (RM 1.5, p = 0.001), fiebre(RM 1.4, p = 0.011), leucocitos en heces (RM 3.2, p = < 0.001), hospitalización en las últimas12 semanas (RM 2.0, p = < 0.001), uso de antibióticos (RM 1.3, p = 0.023) y uso de ceftriaxona(RM 1.4, p = 0.01) constituyeron factores de riesgo independientes para el desarrollo de ICD. Conclusiones: La diarrea por CD en servicios quirúrgicos es frecuente en nuestra institución(Hospital Civil de Guadalajara Fray Antonio Alcalde)

Analisis and tools for performance prediction

We present an analytical model that extends BSP to cover both oblivious synchronization and group partitioning. There are a few oversimplifications in BSP that make difficult to have accurate predictions. Even if the numbers of individual communication or computation operations in two stages are the same, the actual times for these two stages may differ. These differences are due to the separate nature of the operations or to the particular pattern followed by the messages. Even worse, the assumption that a constant number of machine instructions takes constant time is far from the truth. Current memory hierarchies imply that memory access vary from a few cycles to several thousands. A natural proposal is to associate a different proportionality constant with each basic block, and analogously, to associate different latencies and bandwidths with each “communication block”. Unfortunately, to use this approach implies that the evaluation parameters not only depend on given architecture, but also reflect algorithm characteristics. Such parameter evaluation must be done for every algorithm. This is a heavy task, implying experiment design, timing, statistics, pattern recognition and multi-parameter fitting algorithms. Software support is required. We have developed a compiler that takes as source a C program annotated with complexity formulas and produces as output an instrumented code. The trace files obtained from the execution of the resulting code are analyzed with an interactive interpreter, giving us, among other information, the values of those parameters.Eje: Programación concurrenteRed de Universidades con Carreras en Informática (RedUNCI