To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
At a global level, dairy cow production systems (DCPS) are important sources of nourishment and profits, but they generate environmental impacts such as overexploitation of different resources including water, lands and fossil energy. Quantification of water and carbon footprint to define mitigation strategies and a more rational use of natural resources, is a reiterated claim. The aim of this study was to perform an economic evaluation of the environmental impact of the DCPS from the Comarca Lagunera, Mexico (24°N, 102°W, 220 mm, hot-semiarid climate) We contrasted the economic value (EV) generated by the DCPS with respect to the economic costs (EC) due to the greenhouse gas emissions (GHGE) and the water footprint (WFP) of this DCPS. While quantifications of GHGE considered those proposed by the Intergovernmental Panel on Climate Change, the WFP involved the use of blue, gray and green water by the DCPS and related activities. Quantification of the EC of WFP considered an international average price of water. In the year 2017, the Comarca Lagunera registered a dairy cow inventory of 493 144 heads, with 227 142 lactating cows, which produced 2386 million liters of milk per year with an annual average EV of €525.3 million. The EC (€, millions) generated by the GHGE and WFP were €311.8 and €11 980.7, respectively, with a total EC of € 12 292.5 million. When the EV of milk production and the total environmental EC are compared, the contrast demonstrates not only the noteworthy environmental impact but also the significant and senseless biological and EC. In addition, having a large dairy cow concentration creates pollution concerns and the DCPS transfers both nutrients and water resources from an ecologically vulnerable arid region. Therefore, some mitigation strategies such as, better cow genotype, feed and manure management combined with the production of forages and grains in a different geographical region are suggested to promote an optimum use of water in order to uphold the social, economic and biologic sustainability of the Comarca Lagunera, Mexico.
Centrorynchus nahuelhuapensis n. sp. is described from the intestine of Strix rufipes, the rufous-legged owl, in Patagonia, Argentina. This species is characterized by the presence of 31–33 hook rows with 16–17 hooks per row, distributed as follows: 5 true hooks, 4 transitional hooks with 4 alate processes, more evident in the first three, 7–8 spiniform hooks, and three cement glands. It differs from most members of the genus by having a filiform body, the arrangement and size of the hooks, the number of cement glands, and egg size. Part of the SSU and LSU genes were sequenced and compared to those in GenBank. Sequences are most similar to other species of Centrorhynchus, supporting their placement within this genus. We present the first molecular study for a species of Centrorhynchus from South America. Additionally, it is the second species of the genus described in Argentina, and the first species of a terrestrial acanthocephalan from a bird in Patagonia.
Inclusion of legume in grass pastures optimizes protein values of the forage and promotes improved digestibility. Therefore, we hypothesized that finishing steers on a novel combination of legumes and grass pasture would produce carcasses with acceptable traits when compared to carcasses from steers finished in feedlot systems. In this study, we evaluated the effects of finishing steers on three systems including: grazing legume–grass pasture containing oats, ryegrass, white and red clover (PAST), grazing PAST plus supplementation with whole corn grain (14 g/kg BW (SUPP)), and on a feedlot-confined system with concentrate only (28 g/kg BW, consisting of 850 g/kg of whole corn grain and 150 g/kg of protein–mineral–vitamin supplement (GRAIN)) on growth performance of steers, carcass traits and digestive disorders. Eighteen steers were randomly assigned to one of three dietary treatments and finished for 91 days. Data regarding pasture and growth performance were collected during three different periods (0 to 28, 29 to 56 and 57 to 91 days). Subsequently, steers were harvested to evaluate carcass traits, presence of rumenitis, abomasitis and liver abscesses. The legume–grass pasture provided more than 19% dry matter of protein. In addition, pasture of paddocks where steers were assigned to SUPP and PAST treatments showed similar nutritional quality. When compared to PAST, finishing on SUPP increased total weight gain per hectare, stocking rate, daily and total weight gains. The increase of weight gain was high to GRAIN than SUPP and PAST. Steers finished on GRAIN had high hot carcass weight, fat thickness and marbling score when compared to PAST. However, these attributes did not differ between GRAIN and SUPP. Abomasum lesions were more prevalent in steers finished on GRAIN when compared to PAST. Results of this research showed that it is possible to produce carcasses with desirable market weight and fat thickness by finishing steers on legume–grass pasture containing oats, ryegrass, white and red clover. Moreover, supplementing steers with corn when grazing on legume–grass pasture produced similar carcass traits when compared to beef fed corn only.
In the industry, the titanium nitride (TiN) coating is widely used in cutting tools, decorative and corrosion protection film, but unfortunately, this coating presented a poor performance under some work condition. For that, different studies have been dedicated to improving its properties with the inclusion of a third element that modifies the film structure, chemical and mechanical properties. In this work, TiN layers with/without of Al, B, and Cr inclusion were studied in order to analyze their effect in the film tribological performance. These were deposited using cathodic arc PVD technic on AISI-M2 steel. They were chemical and structural characterized using EDX and XRD, respectively. While the film thickness was determinate using a ball-cratering technique. Their tribological performance was studied using a sliding reciprocating movement in dry conditions, under three loads, at 30 min against Al2O3 ball as counterbody. The resulting wear tracks were studied using optical microscopy in order to study the wear mechanism. Raman spectroscopy was used to determinate the chemical changes produced on wear zones and the lost material was measured with a stylus profilometer. As result, the structure and morphology were modified with the inclusion of the third element. The TiN with the inclusion of Al and B presented a higher friction force and wear rate than TiN films. While the TiN with Cr inclusion film presented the best tribological performance with lower wear rate and friction coefficient. The Raman studies did not showed considerable changes on the damage coted surface areas, except for TiAlN coating that show the M2 tool steel Raman spectra on the areas where the film was removed.
The hosts of long Gamma-ray bursts (GRBs) are places of intense star-formation, which, at low redshift, are primarily low-mass dwarf starburst galaxies. Spatially resolved studies of these galaxies are still sparse, even more so at high spectral resolution where we can probe gas kinematics, in- and outflows and differences in abundance between different components. Here we present the first high resolution IFU sample of six low redshift GRB hosts, all dwarf starbursts. All galaxies in our sample show evidence for excess emission or broad emission components, with velocities of 100-200 km s−1. For GRB 030329, outflowing gas had also been observed in absorption in spectra of the GRB afterglow. The high velocity emission is usually blue shifted, connected to the brightest star-forming regions and more metal rich than the narrow component associated with the emission of the general host ISM. This gives strong indications that the excess emission/broad component is indeed associated to a starburst wind as observed in many field star-burst galaxies and a sign for the intense ongoing star-formation in those galaxies.
Human papillomavirus (HPV) is a DNA virus linked to mucosal and cutaneous carcinogenesis. More than 200 different HPV types exist. We carried out a transversal study to investigate the prevalence of HPV types in two regions of Mexico. A total of 724 genital and non-genital samples from women (F) and men (M) were studied; 241 (33%) from North-Eastern (NE) and 483 (66%) from South-Central (SC) Mexico. The overall prevalence was 87%. In genital lesions from females, the NE group showed a prevalence of HPV types 16 (37%), 6 (13%), 59 (6%), 11, 18 and 66 (5.4% each); and the SC group showed types 6 (17%), 16 (15%), 11 (14.5%), 18 (12%) and 53 (6%). In the genital lesions from males, NE group showed types 16 (38%), 6 (21%), 11 (13%) and 59 plus 31 (7.5%) and the SC group showed types 6 (25%), 11 (22%), 18 (17%) and 16 (11.5%). When the two regions were compared, a higher prevalence of low-risk HPV 6 and 11 was found in the SC region and of high-risk HPV 59, 31 and 66 (the latter can also be present in benign lesions) in the NE region. Our findings complement efforts to understand HPV demographics as a prerequisite to guide and assess the impact of preventive interventions.
The objective of this work was to determine the rumen degradation characteristics over the growing season of maize stover in two contrasting zones in the central highlands of Mexico. Twenty four maize plots were selected, three harvest periods P1, P2, and P3 were established in order to evaluate degradation characteristics at different development stages, for ‘criollo’ maize varieties of three grain colours (white, yellow and black) representing different cultivation practices given their different growing cycles. In vitro gas production (GP) incubations were carried out, and cumulative gas volumes were fitted to the Krishnamoorthy, Soller, Steingass and Menke (1991) model. The results indicate that more research is needed to evaluate why maize degradability and fermentation characteristics as exemplified by this work are not greatly affected by time.
We have studied the structural and morphological properties on the pyrochlore (Er2-x Srx)Ru2O6 system, for x = 0.0, 0.02, 0.05, 0.07, 0.10, and 0.15. Polycrystalline samples were prepared by solid-state reaction (SR) and sol-gel acrylamide polymerization (SGAP). Thermogravimetric Analysis (TGA) was used to follow the thermal transformations such as reagents decomposition, phase transformation, chemical stability, and volatilization of organic material of samples. The reagents and synthesized products by the different methods of synthesis were characterized using powder X-ray diffraction (XRD). All samples crystallize Er2Ru2O6 PDF (72-7620) in the cubic unit cell with Fd
m (No. 227) space group and form a solid solution up to x = 0.15. Scanning electron microscopy (SEM) shows considerable variations and similitudes in sizes, very few phases and shapes of polycrystals can be observed. Polycrystalline samples prepared by solid-state reaction (SR) present a grain size varies between 77 nm to 250 nm.
Harnessing the properties of imidazolium species, antimicrobial activity against Gram-negative and Gram-positive bacteria was attained by binary-grafting 2-hydroxyethyl methacrylate (HEMA) or N-isopropylacrylamide, followed by N-vinylimidazole onto polypropylene (PP) monofilaments (sutures) using 60Co γ-rays. Ulterior functionalization with methyl iodide was carried out to endow brushes with antimicrobial activity on the PP surface. The PP-grafted sutures were characterized by means of Fourier-transform infrared spectroscopy attenuated total reflection, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis, and regarding the mechanical properties and the responsiveness to pH and temperature. Tests were performed on Escherichia coli and Staphylococcus aureus achieving large inhibition zones.
Objectives: The present study examined differences in neurocognitive outcomes among non-Hispanic Black and White stroke survivors using the NIH Toolbox-Cognition Battery (NIHTB-CB), and investigated the roles of healthcare variables in explaining racial differences in neurocognitive outcomes post-stroke. Methods: One-hundred seventy adults (91 Black; 79 White), who participated in a multisite study were included (age: M=56.4; SD=12.6; education: M=13.7; SD=2.5; 50% male; years post-stroke: 1–18; stroke type: 72% ischemic, 28% hemorrhagic). Neurocognitive function was assessed with the NIHTB-CB, using demographically corrected norms. Participants completed measures of socio-demographic characteristics, health literacy, and healthcare use and access. Stroke severity was assessed with the Modified Rankin Scale. Results: An independent samples t test indicated Blacks showed more neurocognitive impairment (NIHTB-CB Fluid Composite T-score: M=37.63; SD=11.67) than Whites (Fluid T-score: M=42.59, SD=11.54; p=.006). This difference remained significant after adjusting for reading level (NIHTB-CB Oral Reading), and when stratified by stroke severity. Blacks also scored lower on health literacy, reported differences in insurance type, and reported decreased confidence in the doctors treating them. Multivariable models adjusting for reading level and injury severity showed that health literacy and insurance type were statistically significant predictors of the Fluid cognitive composite (p<.001 and p=.02, respectively) and significantly mediated racial differences on neurocognitive impairment. Conclusions: We replicated prior work showing that Blacks are at increased risk for poorer neurocognitive outcomes post-stroke than Whites. Health literacy and insurance type might be important modifiable factors influencing these differences. (JINS, 2017, 23, 640–652)