A discrete epidemic model for bovine babesiosis disease and tick populations

In this paper, we provide and study a discrete model for the transmission of Babesiosis disease in bovine and tick populations. This model supposes a discretization of the continuous-time model developed by us previously. The results, here obtained by discrete methods as opposed to continuous ones, show that similar conclusions can be obtained for the discrete model subject to the assumption of some parametric constraints which were not necessary in the continuous case. We prove that these parametric constraints are not artificial and, in fact, they can be deduced from the biological significance of the model. Finally, some numerical simulations are given to validate the model and verify our theoretical study

Deslizamientos naturales y comunidades pionera de ecosistemas montanos al occidente del parque nacional podocarpus (ecuador)

El Parque Nacional Podocarpus (PNP), ubicado al sur del Ecuador, ocupa una posición climatológica clave con respecto a la deflexión de Huancabamba aledaña a esta área hacia el sur, que ocasiona una barrera natural de distribución de especies y por otro lado este aislamiento biogeográfíco ha originado especiación florística en algunas especies. La geografía accidentada de esta región, sumada a la escasa capa vegetal y precipitaciones que superan los 6000 mm en los páramos, ocasiona impactos severos en los flancos orientales y occidentales de la baja Cordillera Oriental que no sobrepasa los 3700 m, en sus límites altitudinales más altos. Es aquí donde existe una dinámica alta de deslizamientos, los mismos que si bien afectan la diversidad vegetal, también son considerados un motor generador de continuos procesos de regeneración. Se establecieron 138 parcelas, distribuidas a o largo de un gradiente latitudinal y altitudinal, de 1 x 5m al occidente del PNP, encontrándose 218 especies representantes de 180 géneros y 51 familias; el piso altitudinal de mayor diversidad está a los 2700 m. El análisis TWINSPAN separó nueve comunidades vegetales, mientras que el análisis multivariado CANOCO, determinó que las características edafológicas influyen en la composición de la vegetación, mientras que la altitud y la pendiente no establecen notable diferencia

Estudio de digénidos de peces marinos del sur de la Península Ibérica

Se han estudiado un total de 492 hospedadores pertenecientes a 72 especies de peces marinos, todos procedentes de la plataforma continental que bordea el sur de la Península Ibérica. Como resultado de este trabajo se han localizado en el aparato digestivo de estos hospedadores 39 especies de Digenea. De ellas, Stephanostomum bicoronatum, (Stossich, 1883) Manter, 1940, Parahemiurus merus, (Linton, 1910) Manter, 1940, Derogenes latus Janiszewska, 1953, Bacciger israelensis Fischtha1, 1980, Promnoprymna ventricosa (Rudolphi, 1819) Poche, 1926, Haploporus benedenii (Stossich, 1887) Looss, 1902, Haplosplanchnus pachysomus (Eysenhardt, 1829) Looss, 1902, Saccocoelium obesum Looss, 1902, y Genolopa ampullacea Linton, 1910 se citan por primera vez en la península Ibérica. Lecithochirium musculus (Looss, 1907) Nasir y Díaz, 1971, Lecithochirium rufoviride (Rudolphi, 1819) Lühe, 1901, Lecithochirium fusiforme Lühe, 1901, Ectenurus lepidus Looss, 1907 y Tergestia laticollis (Rudolphi, 1819) Stossich, 1899, en las costas de Andalucia. Stephanostomum minutum en el Mediterráneo peninsular. Wardulla capitel/ata (Rudolphi, 1819) Poche, 1926 y Deropristis inflata en el Atlántico peninsular. Además, con el presente trabajo se amplía considerablemente el espectro de hospedadores de algunas de las especies parásitas estudiadas. Así Halobatrachus didactylus es nuevo hospedador para Stephanostomum minutum (Looss, 1901) Manter, 1940, Anisocladium fallax (Rudolphi, 1819) Looss, 1902 y Anisocoelium capitellatum (Rudolphi, 1819) Lühe, 1900. Bothus podas para Lecithocladium excisum (Rudolphi, 1819) Lühe, 1901 y Derogenes varicus (Müller, 1784) Looss, 1901. Solea sp. para Lecithochirium musculus (Looss, 1907) Nasir y Díaz, 1971. Trachinotus ovatus para Synaptobothrium caudiporum (Rudolphi, 1819) Looss, 1907. Scorpaena scrofa para Derogenes latus Janiszewska, 1953. Belone belone para Tergestia laticollis (Rudolphi, 1819) Stossich, 1899. Dicentrarchus punctatus para Acanthostomum imbutiforme (Molin, 1859) Gohar, 1934 y Bucephalus baeri Maillard, 1976. y Echiichthys vipera para Anisocladiumfallax (Rudolphi, 1819) Looss, 1902 y Anisocoelium capitellatum (Rudolphi, 1819) Lühe, 1900A total of 492 host of72 diferent species ofmarine fishes were colleted from the Sourth Iberian Peninsula coast and their tract digest were examined. We have identified 39 species ofDigenea. Stephanostomum bicoronatum, (Stossich, 1883) Manter, 1940, Parahemiurus merus, (Linton, 1910) Manter, 1940, Derogenes latus Janiszewska, 1953, Bacciger israelensis Fischthal, 1980, Promnoprymna ventricosa (Rudolphi, 1819) Po che, 1926, Haploporus benedenii (Stossich, 1887) Looss, 1902, Haplosplanchnus pachysomus (Eysenhardt, 1829) Looss, 1902, Saccocoelium obesum Looss, 1902, and Genolopa ampullacea Linton, 1910, have not previously been reported from Iberian Peninsula. Furthermore, Lecithochirium musculus (Looss, 1907) Nasir y Díaz, 1971, Lecithochirium rufoviride (Rudolphi, 1819) Lühe, 1901, Lecithochirium fusiforme Lühe, 1901, Ectenurus lepidus Looss, 1907 and Tergestia laticollis (Rudolphi, 1819) Stossich, 1899, are reported for the first time in Andalucian coast; Stephanostomum minutum in the spanish mediterranean coast and finally, Wardulla capitellata (Rudolphi, 1819) Poche, 1926 and Deropristis inflata in the Atlántic peninsular. In this paper, we have thoroughly widened the host range for sorne of the species here studied. So, Halobatrachus didactylus is a new host for Stephanostomum minutum (Looss, 1901) Manter, 1940, Anisocladiumfallax (Rudolphi, 1819) Looss, 1902 and Anisocoelium capitellatum (Rudolphi, 1819) Lühe, 1900. Bothus podas for Lecithocladium excisum (Rudolphi, 1819) Lühe, 1901 and Derogenes varicus (Müller, 1784) Looss, 1901. Solea sp. for Lecithochirium musculus (Looss, 1907) Nasir y Díaz, 1971. Trachinotus ova tus for Synaptobothrium caudiporum (Rudolphi, 1819) Looss, 1907. Scorpaena scrofa for Derogenes latus Janiszewska, 1953. Belone belone for Tergestia laticollis (Rudolphi, 1819) Stossich, 1899. Dicentrarchus punctatus for Acanthostomum imbutiforme (Molin, 1859) Gohar, 1934 and Bucephalus baeri Maillard, 1976. Echiichthys vipera for Anisocladiumfallax (Rudolphi, 1819) Looss, 1902 andAnisocoelium capitellatum (Rudolphi, 1819) Lühe, 190

Characterization of activated carbon fiber/polyaniline materials by position-resolved microbeam small-angle X-ray scattering

Activated carbon fiber (ACF)/polyaniline (PANI) materials have been prepared using two different methods, viz. chemical and electrochemical polymerization. Electrochemical characterization of both materials shows that the electrodes with polyaniline have a higher capacitance than does a pristine porous carbon electrode. To analyze the distribution of PANI within the ACF, characterization by position-resolved microbeam small-angle X-ray scattering (μSAXS) has been carried out. μSAXS results obtained with a single ACF indicate that, for the experimental conditions used, a PANI coating is formed inside the micropores and that it is higher in the external regions of the ACF than in the core. Additionally, it seems that the penetration of PANI inside the fibers occurs in a larger extent for the chemical polymerization or, in other words, for the electrochemically polymerized sample there is a slightly larger accumulation of PANI in the external regions of the ACF.Fil: Salinas-Torres, D.. Universida de Alicante; EspañaFil: Sieben, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Lozano-Castelló, D.. Universida de Alicante; EspañaFil: Morallón, E.. Universida de Alicante; EspañaFil: Burghammer, M.. EuropeanSynchrotronRadiationFacility; FranciaFil: Riekel, C.. EuropeanSynchrotronRadiationFacility; FranciaFil: Cazorla Amorós, Diego. Universida de Alicante; Españ

Silo Clogging Reduction by the Presence of an Obstacle

We present experimental results on the effect that inserting an obstacle just above the outlet of a silo has on the clogging process. We find that, if the obstacle position is properly selected, the probability that the granular flow is arrested can be reduced by a factor of 100. This dramatic effect occurs without any remarkable modification of the flow rate or the packing fraction above the outlet, which are discarded as the cause of the change in the clogging probability. Hence, inspired by previous results of pedestrian crowd dynamics, we propose that the physical mechanism behind the clogging reduction is a pressure decrease in the region of arch formation

Epidemiologia del parasitismo intestinal infantil en el valle del Guadalquivir, España

BACKGROUND : Intestinal parasitisms represents a public health problem that should be periodically assessed in each region. In the present paper, a study about prevalence of intestinal parasites, has been carried out in children from the natural region of the Guadalquivir Valley. METHODS: During the period 1994-1996, 1.917 children without symptoms, aging between 6 and 10, were studied by means of coprologycal analysis and Graham method, all of them living in 20 villages in the Guadalquivir valley. RESULTS: The overall prevalence of intestinal parasitisms have been of 27,12%. The reported parasites and their prevalence are as follows: Enterobius vermicularis (20,44%), Giardia lamblia (5,05%), Entamoeba coli (2,45%), Endolimax nana (1,61%), Entamoeba histolytica (0,31%), Entamoeba hartmanni (0,05%), Iodamoeba bütschlii (0,05%). CONCLUSIONS: The overall prevalence of intestinal parasites is similar to that found in other spanish region, if only a little bit more favourable probably due to the long lasting drought and the improvements in health resourses, no geohelmints have been detected unlike other protozoosis, giardiasis mantains a relatively high prevalence.FUNDAMENTO: Las parasitosis intestinales en los niños constituyen un problema de salud pública que debe ser valorado periódicamente en cada región. En este trabajo se aborda, por primera vez en la región natural del Valle del Guadalquivir, un estudio amplio sobre la prevalencia del parasitismo intestinal en la población infantil de la zona. MÉTODOS: Durante el período 1994-1996, mediante análisis coprológico y método de Graham, se ha estudiado a 1.917 niños y niñas asintomáticos, con edades comprendidas entre seis y diez años, residentes en veinte localidades del Valle del Guadalquivir. RESULTADOS: El índice global de parasitación ha sido del 27,12 %. Las especies parásitas detectadas, así como sus prevalencias fueron: Enterobius vermicularis (20,44%), Giardia lamblia (5,05%), Entamoeba coli (2,45%), Endolimax nana (1,61%), Entamoeba histolytica (0,31%), Entamoeba hartmanni (0,05%), Iodamoeba bütschlii (0,05%). CONCLUSIONES: La prevalencia global encontrada es similar a la de otras regiones españolas, aunque quizás pueda considerarse algo más favorable. No se detectan geohelmintos, debido posiblemente a la mejora de la infraestructura higiénico-sanitaria y a los efectos de la prolongada sequía en la zona. La giardiasis, a diferencia de las restantes protozoosis, mantiene una prevalencia relativamente alta

Propiedades físicas y mecánicas de la madera plástica para uso en estructura de atención y prevención de desastres de la “ESMIC”

In 2017, the INGEMIL research nursery of the Military School of Cadets (ESMIC) proposes a modular physical prototype for the prevention and emergency care attended by the National Army that can provide the energy needed to serve as a collection center for military rescue engineers. This prototype was built with plastic wood, which is a material composed of recycled plastic with wood waste, which offersadvantages in terms of costs, durability, resistance to degradative agents, ease of molding and maintenance­free. As previously stated, plastic wood was characterized physically and mechanically, to promote and approve its use in the prototype built in previous years and begin to implement it in construction materials to observe its behavior. Physical characterization tests such as density andhardness, and mechanical characterization such as compression and flexion were performed.En el año 2017, el semillero de investigación INGEMIL de la Escuela Militar de Cadetes (ESMIC) propuso un prototipo físico modular para la prevención y atención de emergencias que atiende el ejército Nacional que es capaz de proveer la energía necesaria para servir como centro de acopio para los ingenieros militares rescatistas. Este prototipo fue construido con madera plástica, que es un material compuesto por plástico reciclado con residuos de madera, que ofrece ventajas en términos de costos, durabilidad, resistencia a los agentes degradativos, facilidad de moldeado y no requiere mantenimiento. Según lo anteriormente dicho, se caracterizó física y mecánicamente la madera plástica, con el fin de promover y aprobar su uso en el prototipo construido en años anteriores y empezar a implementarlo en materiales de construcción para observar su comportamiento. Se realizaron ensayos de caracterización física como densidad y dureza, yde caracterización mecánica tales como compresión y flexión

Diminished modulation of preparatory sensorimotor mu rhythm predicts attention-deficit hyperactivity disorder severity

BackgroundAttention-deficit/hyperactivity disorder (ADHD) is characterized by problems in regulating attention and in suppressing disruptive motor activity, i.e. hyperactivity and impulsivity. We recently found evidence that aberrant distribution of posterior α band oscillations (8–12 Hz) is associated with attentional problems in ADHD. The sensorimotor cortex also produces strong 8–12 Hz band oscillations, namely the μ rhythm, and is thought to have a similar inhibitory function. Here, we now investigate whether problems in distributing α band oscillations in ADHD generalize to the μ rhythm in the sensorimotor domain.MethodIn a group of adult ADHD (n = 17) and healthy control subjects (n = 18; aged 21–40 years) oscillatory brain activity was recorded using magnetoencephalography during a visuo-spatial attention task. Subjects had to anticipate a target with unpredictable timing and respond by pressing a button.ResultsPreparing a motor response, the ADHD group failed to increase hemispheric μ lateralization with relatively higher μ power in sensorimotor regions not engaged in the task, as the controls did (F1,33 = 8.70, p = 0.006). Moreover, the ADHD group pre-response μ lateralization not only correlated positively with accuracy (rs = 0.64, p = 0.0052) and negatively with intra-individual reaction time variability (rs = −0.52, p = 0.033), but it also correlated negatively with the score on an ADHD rating scale (rs = −0.53, p = 0.028).ConclusionsWe suggest that ADHD is associated with an inability to sufficiently inhibit task-irrelevant sensorimotor areas by means of modulating μ oscillatory activity. This could explain disruptive motor activity in ADHD. These results provide further evidence that impaired modulation of α band oscillations is involved in the pathogenesis of ADHD.</jats:sec

Genetic connectivity between Atlantic bluefin tuna larvae spawned in the Gulf of Mexico and in the Mediterranean Sea

The highly migratory Atlantic bluefin tuna (ABFT) is currently managed as two distinct stocks, in accordance with natal homing behavior and population structuring despite the absence of barriers to gene flow. Larval fish are valuable biological material for tuna molecular ecology. However, they have hardly been used to decipher the ABFT population structure, although providing the genetic signal from successful breeders. For the first time, cooperative field collection of tuna larvae during 2014 in the main spawning area for each stock, the Gulf of Mexico (GOM) and the Mediterranean Sea (MED), enabled us to assess the ABFT genetic structure in a precise temporal and spatial frame exclusively through larvae. Partitioning of genetic diversity at nuclear microsatellite loci and in the mitochondrial control region in larvae spawned contemporarily resulted in low significant fixation indices supporting connectivity between spawners in the main reproduction area for each population. No structuring was detected within the GOM after segregating nuclear diversity in larvae spawned in two hydrographically distinct regions, the eastern GOM (eGOM) and the western GOM (wGOM), with the larvae from eGOM being more similar to those collected in the MED than the larvae from wGOM. We performed clustering of genetically characterized ABFT larvae through Bayesian analysis and by Discriminant Analysis of Principal Components (DAPC) supporting the existence of favorable areas for mixing of ABFT spawners from Western and Eastern stocks, leading to gene flow and apparent connectivity between weakly structured populations. Our findings suggest that the eastern GOM is more prone for the mixing of breeders from the two ABFT populations. Conservation of this valuable resource exploited for centuries calls for intensification of tuna ichthyoplankton research and standardization of genetic tools for monitoring population dynamics.This collaborative study was supported by “ECOLATUN” PROJECT CTM2015-68473-R (MINECO/FEDER) funded by Spanish Ministry of Economy and Competitiveness; “TUNAGEN” project funded by Instituto Español de Oceanografía (IEO); and “BLUEFIN” project financed by IEO and Balearic Island Observing and Forecasting System (SOCIB). This research was funded by NASA (NNX11AP76G S07), the NOAA National Marine Fisheries Science Service through the Southeast Fisheries Science Center, as well as by the Cooperative Institute for Marine and Atmospheric Studies under Cooperative Agreement NA15OAR43200064 at the University of Miami, Miami, FL, USA. There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.En prens

Clogging transition of many-particle systems flowing through bottlenecks

When a large set of discrete bodies passes through a bottleneck, the flow may become intermittent due to the development of clogs that obstruct the constriction. Clogging is observed, for instance, in colloidal suspensions, granular materials and crowd swarming, where consequences may be dramatic. Despite its ubiquity, a general framework embracing research in such a wide variety of scenarios is still lacking. We show that in systems of very different nature and scale -including sheep herds, pedestrian crowds, assemblies of grains, and colloids- the probability distribution of time lapses between the passages of consecutive bodies exhibits a power-law tail with an exponent that depends on the system condition. Consequently, we identify the transition to clogging in terms of the divergence of the average time lapse. Such a unified description allows us to put forward a qualitative clogging state diagram whose most conspicuous feature is the presence of a length scale qualitatively related to the presence of a finite size orifice. This approach helps to understand paradoxical phenomena, such as the faster-is-slower effect predicted for pedestrians evacuating a room and might become a starting point for researchers working in a wide variety of situations where clogging represents a hindrance