Evaluation of the presence of Vibrio parahaemolyticus in white shrimp (Litopenaeus vannamei) estuarine-wild from southern Sinaloa and northern Nayarit by microbiological analysis and PCR

Given the incidence of human poisonings attributed to raw shrimp consumption in southern of Sinaloa and northern of Nayarit in recent years, white shrimp (Litopenaeus vannamei) was sampled from three wildestuaries where it’s been captured and one sample was taken from a sale center in order to determine the possible presence of toxigenic Vibrio parahaemolyticus, from May to December of 2012. Samples were analyzed by Biochemical test and Polymerase Chain Reaction (PCR), they were also tested for the specific an toxicological identification, using molecular oligo nucleotides markers tlh, tdh and trh. The number of positives results were recorded to a table of most probable number (MPN).The number of samples positive for V. parahaemolyticus, weren’t toxigenic and it was demonstrated that they were below the limit established in the Mexican Official Standard NOM-242-SSA1-2009. In conclusion, the present study revealed that consumption of raw shrimp from the dates and sites sampled did not show to be a risk for human gastrointestinal diseases

Optical control over transmission of terahertz radiation through arrays of subwavelength holes of varying size

Thomas Henry Isaac, J. Gómez Rivas, and Euan Hendry, Physical Review B, Vol. 80, article 193412 (2009). "Copyright © 2009 by the American Physical Society."We modulate the transmission of terahertz (THz) radiation through periodic arrays of subwavelength holes in a metallic film by using pulses of visible-wavelength light to photoexcite the semiconducting substrate of the hole arrays. By varying the photodoping level of the semiconductor we are able to switch off the resonant transmission of THz radiation through the array. By varying the size of the holes, we demonstrate the crucial role that surface modes play in the resonant transmission and ultimately in the photomodulation behavior of these structures. We demonstrate that the surface-wave transmission mechanism can allow for very efficient optical modulation of radiation transmission

Transmission of light through periodic arrays of square holes : from a metallic wire mesh to an array of tiny holes

A complete landscape is presented of the electromagnetic coupling between square holes forming a two-dimensional periodic array in a metallic film. By combining both experimental and theoretical results along with a first-principles Fano model, we study the crossover between the physics of metallic wire meshes (when holes occupy most of the unit cell) and the phenomenon of extraordinary optical transmission, which appears when the size of the holes is very small in comparison with the period of the array

Time-resolved broadband analysis of slow-light propagation and superluminal transmission of electromagnetic waves in three-dimensional photonic crystals

A time-resolved analysis of the amplitude and phase of THz pulses propagating through three-dimensional photonic crystals is presented. Single-cycle pulses of THz radiation allow measurements over a wide frequency range, spanning more than an octave below, at and above the bandgap of strongly dispersive photonic crystals. Transmission data provide evidence for slow group velocities at the photonic band edges and for superluminal transmission at frequencies in the gap. Our experimental results are in good agreement with finite-difference-time-domain simulations.Comment: 7 pages, 11 figure

Activation of stylolites as conduits for overpressured fluid flow in dolomitized platform carbonates

This research was developed with funding provided by the Spanish Government I+D+I Research Projects CGL2015-69805-P and CGL2015-66335-C2-1-R, and the Generalitat de Catalunya (2014SGR251). The research also benefited from a grant of the Geological Society of London (Elspeth Matthews Fund 2015) to EGR. The authors would like to thank M. Aston and O. P. Wennberg for the editorial work, and F. Laponi and an anonymous reviewer for their critical and constructive comments.Peer reviewedPostprin

The global NAFLD policy review and preparedness index: Are countries ready to address this silent public health challenge?

Background & Aims: Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent, yet largely underappreciated liver condition which is closely associated with obesity and metabolic disease. Despite affecting an estimated 1 in 4 adults globally, NAFLD is largely absent on national and global health agendas. Methods: We collected data from 102 countries, accounting for 86% of the world population, on NAFLD policies, guidelines, civil society engagement, clinical management, and epidemiologic data. A preparedness index was developed by coding questions into 6 domains (policies, guidelines, civil awareness, epidemi ology and data, NAFLD detection, and NAFLD care management) and categorising the responses as high, medium, and low; a multiple correspondence analysis was then applied. Results: The highest scoring countries were India (42.7) and the United Kingdom (40.0), with 32 countries (31%) scoring zero out of 100. For 5 of the domains a minority of countries were cat egorised as high-level while the majority were categorised as low-level. No country had a national or sub-national strategy for NAFLD and <2% of the different strategies for related conditions included any mention of NAFLD. National NAFLD clinical guide lines were present in only 32 countries. Conclusions: Although NAFLD is a pressing public health prob lem, no country was found to be well prepared to address it. There is a pressing need for strategies to address NAFLD at na tional and global levels. Lay summary: Around a third of the countries scored a zero on the NAFLD policy preparedness index, with no country scoring over 50/100. Although NAFLD is a pressing public health prob lem, a comprehensive public health response is lacking in all 102 countries. Policies and strategies to address NAFLD at the na tional and global levels are urgently needed

Quantitative analysis of stylolite networks in different platform carbonate facies

Stylolites are rough surfaces that form by pressure solution, and present variable geometries and spatial distributions. Despite being ubiquitous in carbonate rocks and potentially influencing fluid flow, it is not yet clear how the type and distribution of stylolite networks relate to lithofacies. This study investigates Lower Cretaceous platform carbonates in the Benicàssim area (Maestrat Basin, Spain) to statistically characterise stylolite morphology and stylolite network distributions in a selection of typical shallow-marine carbonate lithofacies, from mudstones to grainstones. Bedding-parallel stylolite networks were sampled in the field to quantify stylolite spacing, wavelength, amplitude, intersection morphology and connectivity. Grain size, sorting and composition were found to be the key lithological variables responsible for the development of rough anastomosing stylolite networks. Poorly-connected stylolites with large vertical spacings were found to be dominant in grain-supported lithofacies, where grains are fine and well sorted. Anastomosing stylolite networks appear well developed in mud-supported lithofacies with poorly-sorted clasts that are both heterogenous in size and composition. Mud-supported facies feature stylolites that are closely spaced, have high amplitudes and intersection densities, and predominantly present suture and sharp-peak type morphologies. Larger grains and poor sorting favour the formation of stylolites with small vertical spacings, low wavelengths and high amplitudes. This statistical analysis approach requires only limited information, such as that from drill core, and can be used to characterise stylolite morphology and distributions in subsurface carbonate reservoirs

Depositional and structural controls on a fault-related dolostone formation (Maestrat Basin, E Spain)

Fault-related dolomitisation is responsible for the development of numerous hydrocarbon reservoirs hosted in diagenetically-altered carbonates and is therefore critical to hydrocarbon exploration, subsurface storage (i.e. CO2), the formation of associated mineralisation (i.e. MVT-deposits) and for understanding the key controls on subsurface fluid flow. Multiple dolomitised outcrop analogues have been characterised in recent years, but uncertainty still remains as to the controls on dolomitisation in terms of dolostone geobody size and geometries, their distribution and how they impact reservoir quality. Late Tithonian shallow-marine carbonates at Serra Esparreguera in the Maestrat Basin (E. Spain) were partially dolomitised on the seismic scale, resulting in a spectrum of geobodies with varying degrees of spatial connectivity. Dolostone predominantly replaces Polpís Fm wackestones and packstones, and bioclastic grainstones of the Bovalar Fm. Dolostone geobodies transition through vertical stratigraphy from being massive and spatially extensive to localised stratabound bodies as textural heterogeneity increases. Irregular dolostone geometries occur in the Polpís Fm, which is texturally homogenous relative to the overlying Bovalar Fm, cross-cutting bedding in areas with high abundance of faults. Faults occur adjacent to dolostone and constrain its lateral extent across the outcrop. Dolomitisation fronts are typically sharp with morphologies affected by small-scale faults and bedding-parallel stylolites. Dolomitisation occurred under burial conditions and dolostones were later overprinted by phases of calcite and saddle dolomite cementation. The spatial distribution of dolostone is strongly influenced by the depositional heterogeneity and faults, while smaller structures (i.e. metre-scale fractures and stylolites) and bedding surfaces controlled the dolomitisation front geometry. Dolostone geobodies at Serra Esparreguera provide new insights into the structural, depositional and diagenetic controls on dolomitisation at a seismic scale, which can be used as a predictive guide to improve the understanding of carbonate reservoirs with complex paragenetic histories