First isolation report of Arcobacter cryaerophilus from a human diarrhea sample in Costa Rica

ABSTRACT Arcobacter cryaerophilus is an emerging enteropathogen and potential zoonotic agent transmitted by food and water. In Costa Rica, this bacterium has not been associated with cases of human gastroenteritis, even though it has been isolated from farm animals, especially poultry. This paper reports the first isolation of A. cryaerophilus from a human case of bloody watery diarrhea and the virulence genes associated with this isolate

CHMP1A encodes an essential regulator of BMI1-INK4A in cerebellar development

Charged multivesicular body protein 1A (CHMP1A; also known as chromatin-modifying protein 1A) is a member of the ESCRT-III (endosomal sorting complex required for transport-III) complex but is also suggested to localize to the nuclear matrix and regulate chromatin structure. Here, we show that loss-of-function mutations in human CHMP1A cause reduced cerebellar size (pontocerebellar hypoplasia) and reduced cerebral cortical size (microcephaly). CHMP1A-mutant cells show impaired proliferation, with increased expression of INK4A, a negative regulator of stem cell proliferation. Chromatin immunoprecipitation suggests loss of the normal INK4A repression by BMI in these cells. Morpholino-based knockdown of zebrafish chmp1a resulted in brain defects resembling those seen after bmi1a and bmi1b knockdown, which were partially rescued by INK4A ortholog knockdown, further supporting links between CHMP1A and BMI1-mediated regulation of INK4A. Our results suggest that CHMP1A serves as a critical link between cytoplasmic signals and BMI1-mediated chromatin modifications that regulate proliferation of central nervous system progenitor cells

Experimental backwater analysis around bridge waterways

A series of five experiments was ferformed in a two-stage compound shannel including various roughess conditions and different types of bridge models, namely, single-opening semi-circular arch bridge model (ASOSC), multiple-opening semi-circular arch bridge model (AMOSC), single-opening elliptic arch bridge model (ASOE), and single-opening straight-deck bridge model with and without piers (DECK) including different span widths. The performances of six different methods for computing backwater around bridge waterways were compared using the experimental data carefully taken on many combinations of cases. The results of the energy method, momentum method, WSPRO method, Yarnell's method, USBPR method, and arch bridge method were compared with experimental results. The results showed that energy method was able to simulate more accurately the measured backwater values than the other methods. The backwater differences between the experimental values and computed values by the energy method are generally within -3.2% and 0.8% in terms of flow depth. A simple generalized function for estimating bridge backwater is also proposed. © 2005 NRC Canada

Design of a Printed Yagi Array Antenna with Additional Director Element for Broadband Radar Applications

In this paper, design, simulation, production and measurement of a coplanar broad-band microstrip antenna printed on an alumina ceramic substrate is presented. Antenna may be used as an element in a radar applications operating at X-band (8 GHz-12 GHz). The antenna driven system consists of one more directors because of the requirements of directivity. The reason of using high dielectric substrates the antenna can be printed on very small spaces. Antenna in Package structure's temperatures rising up rapidly in radar applications so the use of ceramic substrates also has the advantage of using the antenna in high temperature conditions. The whole structure achieves a measured 52% frequency bandwidth for voltage standing-wave ratio <= 2 and 8-10 dBi absolute gain. The minimum line widths on the antenna is about 25 mu m so thin film technology is used in the fabrication process importance of the antenna

Prediction of afflux on undistorted scale bridge model

This paper presents the results and findings from several sets of experimental data on afflux around bridge waterways in overbank flow condition. The paper also investigates the accuracy, capability, and suitability of one-dimensional hydraulic river modelling software (HEC-RAS and ISIS) to model flow through bridge structure. To eliminate a scaling effect between the laboratory-scale experiments and model techniques, all experimental results were scaled up using an undistorted-scale model in which both the vertical and horizontal scale ratio was 100. A total of six methods of predicting afflux, the energy method, the momentum method, the water surface profile (WSPRO) method, Yarnell's method (in HEC-RAS), the U.S. Bureau of Public Roads (USBPR) method, and the arch bridge method (in ISIS) were compared with scaled up experimental results. The results for ISIS are significantly different from the measured data and the output from HEC-RAS. The energy method and the momentum method in HEC-RAS are the most accurate methods to compute the afflux around the bridge waterways

Experimental investigation of boundary shear stress in smooth rectangular channels

ln this study, the results of some experiments are reported concerning the boundary shear stress, boundary shear force and the aspect ratio. Some empirically derived equations are presented giving the percentage of the total shear force carried by the walls as a function of the breadth/depth ratio. These new empirically derived equations are compared with the equations based on experimental data given by Knight et al

Effects of overbank flow on fluvial sediment transport rates

Some small-scale laboratory results are presented concerning sediment transport rates and stage-discharge relationships in compound channels. The sediment transport data confirm the hypothesis of Ackers (Proceedings of the Institution of Civil Engineers, Water, Maritime & Energy, 1992, 96, No. 6, 167-178) that the bed load concentration generally increases up to bankfull flow, then peaks at around this discharge, before declining again with increasing overbank discharge. Experimental data concerning velocity and boundary shear stress distributions, the interaction between the floodplain and the main channel, and alluvial resistance are also presented. Simple empirical relationships summarise the discharge, sediment transport rate, division of flow, resistance, and boundary shear force data, to aid comparison with other experimental studies and numerical river simulation models that simulate the geomorphological response of rivers to flood events

Experimental analysis of boundary shear stress in smooth rectangular channels [Pürüzsüz Dikdörtgen Kesitli Yataklarda Cidar Kayma Gerilmesinin Deneysel Analizi]

In this study, the results of some experiments are reported concerning the boundary shear stress, boundary shear force and aspect ratio. Some empirically derived equations are presented which gives the percentage of the total shear force carried by the walls as a function of the breadth/depth ratio. These new empirically derived equations are compared with the equations based on experimental data given by Knight et al