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Parasites inflict many costs on their hosts. Understanding host–parasite relationship eco-evolutionary dynamics needs appreciation of how parasites affect individual fitness, survival and reproductive potential, and how they combine to influence population demography, dynamics and viability; also, how these processes drive microevolutionary processes that define natural and sexual selection. We synthesise work on the relationship between the red grouse and its main parasite, a gastrointestinal nematode. At individual level, we show how parasites impose a physiological cost, measured by immunosuppression and increased oxidative stress, and how their impact varies depending on contexts. We describe how parasite infection constrains expression of sexually selected traits and summarise how relationships between parasite, host and environment shape host population demography and dynamics. Genetic analyses in red grouse suggest nematode burden is moderately heritable, underpinned by a potentially large array of genes involved in the immune system, energy balance and broader homeostatic processes. There is no clear association between allele frequencies among populations and differences in nematode burdens. Possibly, beneficial alleles for parasite resistance cannot spread through the population due to the strong diversifying e?ects of gene ?ow and genetic drift.
The indications for expanded endoscopic transnasal approaches continue to increase, with more complex skull base defects needing to be repaired. This study reviews the management of large anterior skull base defects with opening of the sellar diaphragm.
A prospective analysis of endonasal endoscopic surgery carried out at Son Espases University Hospital between January 2013 and December 2018 was performed. The analysis included only the cases with a significative intra-operative cerebrospinal fluid leak. In all cases, reconstruction was performed by combining the gasket seal technique with a pedicled mucosal endonasal flap.
Twenty-eight patients were included. The mucoperiosteal nasoseptal flap, the lateral wall flap and the middle turbinate flap were used in 13, 8 and 7 patients, respectively, combined with the gasket seal technique. One case of post-operative cerebrospinal fluid leak was observed (3.57 per cent).
The combination of a gasket seal with an endonasal mucosal flap is an excellent technique for repairing large anterior skull base defects.
The aim of this study was to describe individuals seeking care for injury at a major emergency department (ED) in southern Puerto Rico in the months after Hurricane Maria on September 20, 2017.
After informed consent, we used a modified version of the Natural Disaster Morbidity Surveillance Form to determine why patients were visiting the ED during October 16, 2017–March 28, 2018. We analyzed visits where injury was reported as the primary reason for visit and whether it was hurricane-related.
Among 5 116 patients, 573 (11%) reported injury as the primary reason for a visit. Of these, 10% were hurricane-related visits. The most common types of injuries were abrasions, lacerations, and cuts (43% of all injury visits and 50% of hurricane-related visits). The most common mechanisms of injury were falls, slips, trips (268, 47%), and being hit by/or against an object (88, 15%). Most injury visits occurred during the first 3 months after the hurricane.
Surveillance after Hurricane Maria identified injury as the reason for a visit for about 1 in 10 patients visiting the ED, providing evidence on the patterns of injuries in the months following a hurricane. Public health and emergency providers can use this information to anticipate health care needs after a disaster.
In dairy goats, the kid rearing system can have critical importance in financial returns. Commonly used criteria for the choice of rearing system are not always clear due to the high number of factors involved. The aim of this study was to quantify all those factors to facilitate decision making. So, the effect of two different kid rearing systems, mixed rearing system (MRS) and artificial rearing system (ARS), on milk yield, milk composition and somatic cell count (SCC), milk yield loss at weaning for MRS, kid growth and costs of the different traits on the financial returns in Murciano-Granadina breed goats was studied. Twenty-four goats per group were used. In the MRS, goats reared only one kid, which had free access to goat milk 24 h a day and were weaned at week 6 of lactation, whereas kids in the ARS were separated from their mothers at kidding, colostrum and artificially reared. In both systems, dams were machine-milked once a day throughout lactation and the records took place weekly. Potential milk yield was estimated according to the oxytocin method up to week 12 of lactation, and was similar for both rearing systems, although a 12.3% drop in potential milk yield at weaning was observed for MRS. During the first 6 weeks of lactation, marketable milk was lower for dams in MRS compared to those in ARS (72.1 v. 113.0 l), but similar for the rest of the experiment (101.5 v. 99.4 l, respectively). Marketable milk composition and SCC throughout the 12 weeks of lactation were unaffected by the rearing system. Artificial rearing system entailed an increment in production cost of 22.2€ per kid compared to the rearing by MRS. A similar economic return per goat and kid was obtained from ARS and MRS in this experiment, although, due to one herd’s prolificacy of 1.8, the actual results would be 16.2€ per goat in favour of MRS. The real interest of this experiment may be the possibility of extrapolation to different flocks with diverse levels of milk production, prolificacy and prices and costs for incomes and outputs, to estimate the production system that increases returns. In conclusion, the results showed an increase in the cost of €22.2 per kid bred in the ARS, compared to the MRS, and a final return of 16.2€ per goat in favour of the mixed system.
To investigate whether amnestic mild cognitive impairment (aMCI) identified with visual memory tests conveys an increased risk of Alzheimer’s disease (risk-AD) and if the risk-AD differs from that associated with aMCI based on verbal memory tests.
4,771 participants aged 70.76 (SD = 6.74, 45.4% females) from five community-based studies, each a member of the international COSMIC consortium and from a different country, were classified as having normal cognition (NC) or one of visual, verbal, or combined (visual and verbal) aMCI using international criteria and followed for an average of 2.48 years. Hazard ratios (HR) and individual patient data (IPD) meta-analysis analyzed the risk-AD with age, sex, education, single/multiple domain aMCI, and Mini-Mental State Examination (MMSE) scores as covariates.
All aMCI groups (n = 760) had a greater risk-AD than NC (n = 4,011; HR range = 3.66 – 9.25). The risk-AD was not different between visual (n = 208, 17 converters) and verbal aMCI (n = 449, 29 converters, HR = 1.70, 95%CI: 0.88, 3.27, p = 0.111). Combined aMCI (n = 103, 12 converters, HR = 2.34, 95%CI: 1.13, 4.84, p = 0.023) had a higher risk-AD than verbal aMCI. Age and MMSE scores were related to the risk-AD. The IPD meta-analyses replicated these results, though with slightly lower HR estimates (HR range = 3.68, 7.43) for aMCI vs. NC.
Although verbal aMCI was most common, a significant proportion of participants had visual-only or combined visual and verbal aMCI. Compared with verbal aMCI, the risk-AD was the same for visual aMCI and higher for combined aMCI. Our results highlight the importance of including both verbal and visual memory tests in neuropsychological assessments to more reliably identify aMCI.
Early, conforming antibiotic treatment in elderly patients hospitalised for community-acquired pneumonia (CAP) is a key factor in the prognosis and mortality. The objective was to examine whether empirical antibiotic treatment was conforming according to the Spanish Society of Pulmonology and Thoracic Surgery guidelines in these patients. Multicentre study in patients aged ⩾65 years hospitalised due to CAP in the 2013–14 and 2014–15 influenza seasons. We collected socio-demographic information, comorbidities, influenza/pneumococcal vaccination history and antibiotics administered using a questionnaire and medical records. Bivariate analyses and multilevel logistic regression were made. In total, 1857 hospitalised patients were included, 82 of whom required intensive care unit (ICU) admission. Treatment was conforming in 51.4% (95% confidence interval (CI) 49.1–53.8%) of patients without ICU admission and was associated with absence of renal failure without haemodialysis (odds ratio (OR) 1.49, 95% CI 1.15–1.95) and no cognitive dysfunction (OR 1.71, 95% CI 1.25–2.35), when the effect of the autonomous community was controlled for. In patients with ICU admission, treatment was conforming in 45.1% (95% CI 34.1–56.1%) of patients and was associated with the hospital visits in the last year (<3 vs. ⩾3, OR 2.70, 95% CI 1.03–7.12) and there was some evidence that this was associated with season. Although the reference guidelines are national, wide variability between autonomous communities was found. In patients hospitalised due to CAP, health services should guarantee the administration of antibiotics in a consensual manner that is conforming according to clinical practice guidelines.
The excessive consumption of carbohydrates is related to non-alcoholic fatty liver disease (NAFLD) in infants and adults. The effect of combining maternal malnutrition and a high carbohydrate intake on the development of NAFLD in adulthood remains unknown. We therefore hypothesized that consumption of 5% sucrose by the offspring of dams fed a low-protein diet during pregnancy promotes liver fat accumulation and oxidative damage differently in females and males. To test this, 12-month-old female and male offspring of mothers fed a Control (C) or low-protein diet (Restricted, R) were provided with either tap water or 5% sucrose for a period of 10 weeks. Livers were excised to measure the fat content and 3-nitrotyrosine (3-NTyr) immunostaining; serum samples were also obtained to measure the concentration of malondialdehyde (MDA). Data were analyzed using a non-repeated measures three-way analysis of variance to determine significant differences (P<0.05) regarding to the interaction among maternal diet, sucrose consumption and sex. Results showed that the liver fat content of females from R mothers was higher than that of their male counterpart. Hepatic 3-NTyr immunostaining and serum MDA concentrations were not affected by the interaction involving maternal diet, sucrose consumption and sex. Otherwise, liver fat content was correlated with the hepatic 3-NTyr immunostaining and serum MDA concentrations only in females. Thus, sucrose intake in adulthood increases fat content in the female but not in the male rat offspring of dams fed with a low-protein diet during pregnancy. This research emphasizes the importance of a balanced diet during pregnancy and the influence of the diet on the adult offspring.
Collagen associated with bone samples is frequently used for radiocarbon (14C) dating of bones recovered from archaeological sites. However, submersion and exposure to moisture favors the degradation of collagen, which leads to difficulty in reliably dating bones from tropical, humid, or previously submerged archaeological sites. In this paper, we characterized the preservation state of a series of bones, through parameters such as %C, %N, C/N ratio, and collagen recovery. We performed 14C analyses of three collagen fractions obtained through the pretreatment steps (total, ultrafiltered, and insoluble collagen) in order to link the preservation state and the reproducibility of 14C values obtained from the three fractions. Collagen ultrafiltration resulted in a decrease of C/N ratio, although collagen yield was reduced. When two or three collagen fractions were obtained, ages were reproducible and consistent with expected values, according to archaeological or hydrogeological criteria. The pretreatment steps were monitored by infrared spectroscopy in order to analyze the collagen fractions at the molecular level. The presence of collagen in the total and insoluble fractions was confirmed. Since many of the Mexican samples had poor ultrafiltered collagen yield (<3%) or nonexistent yield, our results show that if additional contextual information is carefully considered, the remnant collagen in the total and insoluble fraction can be dated, especially from sites where no other datable fraction exists.
A controversy at the 2016 IUCN World Conservation Congress on the topic of closing domestic ivory markets (the 007, or so-called James Bond, motion) has given rise to a debate on IUCN's value proposition. A cross-section of authors who are engaged in IUCN but not employed by the organization, and with diverse perspectives and opinions, here argue for the importance of safeguarding and strengthening the unique technical and convening roles of IUCN, providing examples of what has and has not worked. Recommendations for protecting and enhancing IUCN's contribution to global conservation debates and policy formulation are given.
In the Almenara marsh (western Mediterranean), four cores were analyzed to establish the relationship between the marsh record of the Almenara marshlands and the environmental factors responsible for its evolution during the Holocene. One hundred and eighty-six samples were collected for sedimentologic and paleontological study: 63 for biomarker analysis; 5 for amino acid racemization (AAR) dating; and 5 for 14C dating. Litho and biofacies analyses identified distinct paleoenvironments, with the presence of a marsh environment alternating with inputs of alluvial material and marine sediments. Biomarkers indicated the constant presence of terrestrial (herbaceous) plants, together with a variable development of aquatic macrophytes. During the Holocene transgression, the Almenara marsh was occupied by oligohaline marsh facies with an oscillating water level and peat formation, which was established at the bottom of the record at 7570 cal yr BP and persisted until 3100±780 yr (AAR). Maximum surface flooding occurred at 5480 cal yr BP, registered 450m from the current coastline. At least three peat beds (dated with 14C dating and AAR) correlated with Bond (episode 5900 cal yr BP) and Wanner (episodes 4800–4500 and 3300–3500 cal yr BP) cycles and thus correspond to a regional model that affected the Northern Hemisphere.
Our previous work revealed substantial heterogeneity in the cognitive profile of bipolar disorder (BD) due to the presence of three underlying cognitive subgroups characterized as: globally impaired, selectively impaired, or cognitively intact. In an effort to determine whether these subgroups are differentially related to genetic risk for the illness, we investigated whether cognitive deficits were more pronounced in unaffected siblings (UAS) of BD probands within identified clusters.
Cluster analysis was used to identify cognitive clusters in BD (N = 60). UAS (N = 49) were classified into groups according to their proband sibling's cluster assignment; comparisons were made across all clusters and healthy controls (HCs; N = 71).
Three cognitive clusters in BD emerged: a globally impaired (36.7%), a selectively impaired (30%), and a cognitively intact cluster (33.3%). UAS showed a qualitatively similar pattern to their BD siblings; UAS of the globally impaired BD cluster showed verbal memory and general cognitive impairments relative to HCs. In contrast, UAS of the other two clusters did not differ from HCs.
This study corroborates findings from prior work regarding the presence of cognitive heterogeneity in BD. UAS of subjects in the globally impaired BD cluster presented with a qualitatively similar cognitive profile to their siblings and performed worse than all other BD clusters and UAS groups. This suggests that inherited risk factors may be contributing to cognitive deficits more notably in one subgroup of patients with BD, pointing toward differential causes of cognitive deficits in discrete subgroups of patients with the disorder.
Commercial aluminum alloys corresponding to Al-Cu-Si family are commonly used in casting and molding process because their high castability. The main characteristics of these alloys are the excellent weight/strength relation in conjunction with wear and corrosion resistance. Additionally, the mechanical properties of these alloys could be enhanced by heat treatment.
In Al A319 alloys, Cu and Mg are the main responsible to increase the mechanical properties after T6 heat treatment due to the precipitation of Al2Cu and Mg2Si and Al2CuMg phase . Combined effects of Ni and Cu improve strength and hardness at relatively elevated temperature , Due to the low solubility of Ni in Al (0.04%), it has been reported the formation of FeAl9FeNi-type intermetallic, which is not totally dissolved with the typical solution treatments used in aluminum alloys . Hayajneh et al., found that increasing amounts of intermetallic compounds Al3Ni, Al3(CuNi)2 and Al7Cu4Ni in Al-Cu alloy, the hardness increase .
The effect of Ni addition and solution treatment time on the microstructure and hardness of the Al A319 alloy are studied by Vickers microhardness (VHN), Rockwell B hardness (HRB), X Ray Diffraction (XRD), Optical Microscopy (OM), Scanning Electron Microscopy (SEM).
The main purpose of this research was to establish the effectiveness of the V844 corrosion inhibitor for seawater on various metallic materials: carbon steel, aluminum and copper alloy at different concentrations via colloid formation. The changes in both physical and chemical properties of seawater, including pH, total hardness, alkalinity, total dissolved solids (TDS) and conductivity at different concentrations of V844 were assessed, too. The test procedure involves dissolving the V844 corrosion inhibitor powder provided by Magna International Private Limited in seawater to obtain a stock solution of 4% V844 in seawater, which was further diluted to obtain the remaining concentrations. The analysis of parameters begun when various metal species, polished beforehand, were placed into the solutions. The analysis was observed over a period of 26 days and a total of 9 sets of readings were obtained. From our observation and analysis, it was concluded that the inhibitor worked best at 0.05% concentration for carbon steel.
Corrosion is a worldwide, crucial problem that strongly affects natural and industrial environments, in particular the oil and gas industry. Natural gas (NG) is a source of energy in industrial, residential, commercial and electric applications. The abundance of NG in many countries augurs a profitable situation for the vast energy industry. NG is considered friendlier to the environment and with lesser greenhouse gas emissions as compared with other fossil fuels. In the last years, shale gas is increasingly exploited in U.S. and Europe, applying a hydraulic fracturing technique, for releasing gas from the bed rock by injection of saline water, acidic chemicals and sand to the wells. Various critical sectors of the NG industry infrastructure suffer from several types of corrosion: steel casings of production wells and their drilling equipment; gas conveying pipelines including pumps and valves; plants for regasification of liquefied natural gas (LNG) and municipal networks of NG distribution to the consumers. Practical technologies that minimize or prevent corrosion include selection of corrosion resistant engineering materials, cathodic protection, corrosion inhibitors, and application of external and internal paints, coatings and linings. Mexico is undergoing an intense reform process of the energy sector, that involves its oil, NG and electricity industries. Typical cases of corrosion management in the NG industry are presented based on the authors experience and knowledge.
The aim of this work was to assess the corrosion and degradation effects of a biofuel on metallic materials tested in an experimental internal combustion engine (ICE). Biodiesel is considered as an alternative fuel for diesel, for industrial applications ranging from boilers to ICE. The experimental vehicle motor, fitted with carbon steel, stainless steel, aluminum alloys and magnesium alloys was operated with local biodiesel. The corrosion performance was evaluated by gravimetric, chemical and electrochemical techniques, following the practices recommended in ASTM and NACE standards for corrosion testing. This work is the result of an international cooperation between the Institute of Engineering, Autonomous University of Baja California, Mexico and the Corrosion Research Center, Sami Shamoon College of Engineering, Israel. The characteristics and conditions of the ICE operated with biodiesel, and the results of the corrosion essays are presented, analyzed and discussed.
The combat fields of modern wars, including the struggle against global terrorism, are localized in diverse, harsh regions: tropical, desert, artic, marine, with varied weather conditions, which adversely affect the corrosion performance of the equipment and facilities involved.
For the sake of brevity, three groups of military mobile and fixed equipment and structures are dealt with: armored ground wheeled vehicles; naval aluminum vessels, and buildings and facilities for providing dwellings, weapons storage and services to the armed forces. They are usually made from carbon steel, aluminum alloys and reinforced concrete, because of their useful properties: high strength, easy availability and low cost. However, due to their limited corrosion resistance they should be protected by coatings (including military coatings), but primarily paint; cathodic protection and corrosion inhibitors.
All these systems suffer from several types of localized corrosion and degradation: galvanic, pitting, intergranular, dealloying, cavitation, erosion, stress cracking, UV effects in plastics and organic coatings. The military assets require the implementation of corrosion control methods and techniques through all their stages: design, construction, installation and operation. Typical cases of corrosion will be presented based on the authors experience and knowledge.
Two machines: The human body and the vehicle motor are made of structural and functional, natural and man-produced materials. They generate energy by chemical oxidation of two fluids: ethanol and gasoline. The characteristics of these fluids: a nutritive beverage and a fuel, providing motion to the vehicle, are described. The damage due to diseases in the body by excessive ethanol consumption and deterioration of the motor by corrosion are treated by means of preventive and curative methods: body rehabilitation and car repair, maintaining both machines in permanent, healthy, working operation. The chemical reactions of ethanol oxidation and gasoline combustion and their effects on the machines and their materials are presented, illustrated and discussed.
Concrete is a composite material, composed of cement, sand, gravel and water, reinforced with steel bars or mesh. It is used for the construction of infrastructure assets such as airports, dams, ports, bridges and road ways. Polymer concrete is a relative new material containing a thermosetting resin (instead of water) displaying improved mechanical strength, low permeability, greater corrosion resistance and higher durability. It is employed for new construction and old concrete reparation in the chemical, food, fertilizer, mine and civil industries. Polymer concrete pipe specimens, reinforced with glass-fibers were prepared and exposed in a salt spray (fog) chamber, operating with a NaCl solution, following ASTM standard B-117-11. The deterioration effects were assessed by testing the physical and mechanical properties, before and after the exposure in the spray chamber, in accordance with standard ASTM D3039-2013. Corrosion resistance was evaluated applying ASTM standard C876-2013. The result of this work are presented, illustrated and discussed.