Colombian creole breeds Blanco Orejinegro (BON) and Sanmartinero (SM) are widely used as pure breeds and in crossbreeding programs due to their excellent performance in the double ability of milk and ...meat production. We examined genomic regions and genes that from generation to generation have been selected by positive natural selection in favor of the adaptability and reproductive performance of these two Colombian creole breeds. Natural selection of genomics region and genes is one of the main evolutive changes resulting in phenotypic adaptations. The selected genomic regions can be detected by comparing differences in regional linkage disequilibrium (LD) between cattle populations with potential adaptations for economic traits. In this study, we used 58,868 single nucleotide polymorphisms (SNPs) from BON and 57482 SNPs from SM, using genotyping data from 1262 BON and 742 SM animals to estimate the variation of genome-wide LD between populations using the VARLD program. The top 0.1 and 0.01th percentiles of standardized VarLD scores were used as a criterion for all comparisons. A total of 10 selection signatures on chromosomes 3, 5, 11, 15, 18, 21, 22, 23, 25 and 29 were identified in all populations. These signatures overlapped with quantitative trait loci for adaptability and reproductive performance in both breeds. Within the signature located between 23,903,882 and 23,955,588 bp on chromosome 18, we identified the SLC6A2 gene involved in the response to high stress. Also, we identified the genes CTDSP2, CES1, CFAP161, CLEC14A, HIPK1, RBM4, SSTR involved in the expressions of economic traits (meat and milk production), KDMID, OLFML3 genes involved in reproductive traits (age at first calving and calving interval), and ATP23, LRRTM1, SLC6A2, DEK, SYT6, KDMID genes involved in cellular stress response and response to important environmental changes such as high temperature. We conclude that these genomic regions seem to point toward a recent selection in BON and SM populations. These regions can be used in selection and conservation programs.
Level of education is a well-established risk factor for Alzheimer disease but its relation to cognitive decline, the principal clinical manifestation of the disease, is uncertain.
More than 6,000 ...older residents of a community on the south side of Chicago were interviewed at approximately 3-year intervals for up to 14 years. The interview included administration of four brief tests of cognitive function from which a previously established composite measure of global cognition was derived. We estimated the associations of education with baseline level of cognition and rate of cognitive change in a series of mixed-effects models.
In an initial analysis, higher level of education was related to higher level of cognition at baseline, but there was no linear association between education and rate of change in cognitive function. In a subsequent analysis with terms to allow for nonlinearity in education and its relation to cognitive decline, rate of cognitive decline at average or high levels of education was slightly increased during earlier years of follow-up but slightly decreased in later years in comparison to low levels of education. Findings were similar among black and white participants. Cognitive performance improved with repeated test administration, but there was no evidence that retest effects were related to education or attenuated education's association with cognitive change.
The results suggest that education is robustly associated with level of cognitive function but not with rate of cognitive decline and that the former association primarily accounts for education's correlation with risk of dementia in old age.
Aluminium–air cells are high-energy density (<400 W h kg−1) primary batteries developed in the 1960s. This review shows the influence of the materials, including: aluminium alloy, oxygen reduction ...catalyst and electrolyte type, in the battery performance. Two issues are considered: (a) the parasitic corrosion of aluminium at open-circuit potential and under discharge, due to the reduction of water on the anode and (b) the formation of a passive hydroxide layer on aluminium, which inhibits dissolution and shifts its potential to positive values. To overcome these two issues, super-pure (99.999 wt%) aluminium alloyed with traces of Mg, Sn, In and Ga are used to inhibit corrosion or to break down the passive hydroxide layer. Since high-purity aluminium alloys are expensive, an alternative approach is to add inhibitors or additives directly into the electrolyte. The effectiveness of binary and ternary alloys and the addition of different electrolyte additives are evaluated. Novel methods to overcome the self-corrosion problem include using anionic membranes and gel electrolytes or alternative solvents, such as alcohols or ionic liquids, to replace aqueous solutions. The air cathode is also considered and future opportunities and directions for the development of aluminium–air cells are highlighted.
► Discussion of the rationale to choose a suitable alloy for Al–air battery. ► Effect of the properties and preparation route to enhance the oxidation of Al. ► Effect of the inhibitors on the anode oxidation in the alkaline electrolyte. ► Comparison of the performance of high-activity oxygen reduction electrodes.
Electrochemical cells continue to be important in the synthesis and processing of commodity and speciality chemicals, environmental remediation, energy conversion and electrodeposition. A current ...challenge is an increasing need to achieve a high performance from cells which can be easily designed, manufactured or modified. Conventional manufacturing has involved machining of cast and extruded materials in a mechanical engineering workshop, which can involve delays, the need for skilled specialists and considerable costs. Increasingly, the benefits of fast prototyping as a route to manufacture are being realised. Modern approaches to detailed imaging of structures (e.g. by computed tomography) can be combined with on-screen, digital design (via computer software suites), followed by modification then data export to a 3D printer. In this fashion, a fast, flexible, cost effective and attractive route to manufacture of prototype electrodes and cell bodies can be realised. This review paper demonstrates the success of a design-image-manufacture cycle to realise polymeric electrochemical flow cell compartments and electrodes. Future developments are suggested, with 3D printing likely to offer creative solutions in many surface finishing applications.
Plane parallel electrodes are favoured, in laboratory studies and industry, for electrosynthesis, environmental treatment and energy conversion. This electrode geometry offers uniform current ...distribution, while a flow channel ensures a controlled reaction environment. Performance can be enhanced by the use of tailored electrode surfaces, porous, three-dimensional (3D) electrodes and bipolar electrical connections. Scale-up can be achieved by increasing the electrode size, the number of electrodes in a stack, or the number of stacks in a system. Recent trends include (a) 3D printing of fast prototype cell components, (b) use of porous 3D electrode supports and their decoration, (c) development of microflow cells for electrosynthesis, (d) anodic Fenton oxidations for wastewater treatment and (e) computational models to simulate and rationalise reaction environment and performance. Future research needs are highlighted.
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A film of iridium and tin dioxides doped with antimony oxide (IrO2‐SnO2‐Sb2O5) was deposited onto Ti mesh and plate substrates by the Pechini method. The electrode surface morphology and composition ...were characterized by SEM‐EDS. The ternary oxide coating was used for the anodic oxidation of methyl orange (MO) azo dye. Linear sweep voltammetry was used to identify the electrode potentials that favour MO degradation. Batch electrolyses were then carried out at a constant electrode potential of 1.5, 1.75 and 2.0 V vs. SHE using either a three‐electrode batch cell or a flow reactor. The dye solutions were totally decolorized via reactive oxygen species, such as •OH, H2O2 and O3 formed in situ from water oxidation at the Ti/IrO2‐SnO2‐Sb2O5 surface.
Degradation of toxic dyes in colored wastewaters poses a major problem in the textile industry. In this study electrochemical incineration of such dyes is investigated, using Pt electrodes coated with a mixed metal oxide film of IrO2‐SnO2‐Sb2O5. The films were prepared using the Pechini method and used in an electrochemical flow cell reactor to oxidize organic material under different conditions in order to evaluate their application.
•A novel multi-sensor infrared non-dispersive was developed.•The new multi-sensor NDIR was probed to measure carbon dioxide (CO2) and methane (CH4) from river sediments in situ.•A gas extraction ...chamber was designed and built based on the biogas yield under the extraction by ultrasound.•The specific methanogenic activity was measured to evaluate the biogas yield.
A novel multi-sensor infrared non-dispersive was developed and used to measure carbon dioxide (CO2) and methane (CH4) from river sediments. The infrared filters were developed considering the bandwidth (BW) and central wavelength (CWL) of the infrared spectra of gases. Experiments were performed using sediments from the Lerma River taken during the rainy and dry seasons in order to determine the dimensions of sensor and the gas concentration detection limits (SPAN). The sensor and the extraction chamber dimensions were determined based on the biogas yield under the extraction by ultrasound and specific methanogenic activity (SMA), while SPAN values were established from the results of gas concentration measured by gas chromatography. The volume of sensor was 2.23 mL and selected SPAN values were fixed to 20% for CH4 and CO2 from the calibration and the gas obtained from sediments.
The internal manifold geometry strongly influences the flow distribution inside an electrochemical reactor. The mass transport coefficient is a function of the flow pattern and is a key parameter in ...successful electrochemical reactor design and scale-up. In this work, a commercial computational flow dynamics (CFD) package was used to describe the flow pattern in the FM01-LC reactor at controlled volumetric flow rates (corresponding to mean linear flow velocities past the electrode surface between 0.024 and 0.11 m s
−1
). Numerical
Re
numbers were obtained for each local flow velocity at different positions in the reactor channel. From a known mass transport correlation (based on dimensionless groups, i.e.
Sh
,
Re
,
Sc
), numerical
k
m
values were obtained (in the range 200 <
Re
< 1,000) at different positions in the reactor channel. Computed
k
m
numbers are compared against experimental values. This computational approach could be useful in reactor design or selection since it facilitates a fast, preliminary reactor flow and mass transport characterisation without experimental electrochemical measurements.
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