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An understanding of the mechanisms that determine host and parasite relationships is a central aim in parasitology. Association of a parasite species with a host species may be influenced primarily by phylogenetic constraints that cause parasite species to co-speciate with their host species, or predominantly by ecological parameters that influence all other co-evolutionary scenarios. This study aimed to investigate the role of co-speciation as well as other co-evolutionary scenarios in influencing the assemblages of tapeworm parasites (marine cestodes) in skate hosts (Rajiformes) using a modification of the PACo (Procrustean Approach to Cophylogeny) method. The study found that phylogeny and host ecology are both significant predictors of skate–tapeworm relationships, implying that co-speciation as well as other co-evolutionary scenarios are shaping these associations. The study also investigated the key ecological parameters influencing host-switching and found that host diet, distribution depth, average body size and geographical location have a combined effect. Given the importance of parasites in ensuring healthy and stable marine ecosystems, the findings of this study have implications for conservation management worldwide.
Aflatoxin is a fungal toxin contaminating corn and causing liver cancer in humans and animals. Contamination is driven by high temperatures and drought. Aflatoxin assessment is expensive so extension services need to identify high risk areas so irrigation, planting strategies and corn varieties can be adapted. This research presents a web-based decision support tool for risk illustrated with a case study from southern Georgia. The tool employs the approach, developed by Kerry et al. (2017b) where exceedance of key thresholds in temperatures, rainfall, soil type and corn production are used to determine risk. The tool also includes NDVI to indicate drought stress and could be further expanded to include new risk factors and adapted to other crops.
Aflatoxin contamination of food can cause liver cancer in humans and animals. Identification of aflatoxin risk areas allows farmers to adapt management strategies before planting, during growth and at harvest. Aflatoxin contamination is driven by high temperatures and drought conditions and crops grown on light textured soil in the south eastern USA are at particular risk. Aflatoxin assessment is expensive so a role of extension services in precision farming is to identify the areas most at risk of contamination so that farmers can adapt irrigation or planting strategies. This paper extends a county-level risk factors approach developed by Kerry et al. (2017) by investigating the use of NDVI and thermal IR data to indicate drought stress and thus aflatoxin contamination risk at the sub-county level.
The need for higher energy density batteries has spawned recent renewed interest in alternatives to lithium ion batteries, including multivalent chemistries that theoretically can provide twice the volumetric capacity if two electrons can be transferred per intercalating ion. Initial investigations of these chemistries have been limited to date by the lack of understanding of the compatibility between intercalation electrode materials, electrolytes, and current collectors. This work describes the utilization of hybrid cells to evaluate multivalent cathodes, consisting of high surface area carbon anodes and multivalent nonaqueous electrolytes that are compatible with oxide intercalation electrodes. In particular, electrolyte and current collector compatibility was investigated, and it was found that the carbon and active material play an important role in determining the compatibility of PF6-based multivalent electrolytes with carbon-based current collectors. Through the exploration of electrolytes that are compatible with the cathode, new cell chemistries and configurations can be developed, including a magnesium-ion battery with two intercalation host electrodes, which may expand the known Mg-based systems beyond the present state of the art sulfide-based cathodes with organohalide-magnesium based electrolytes.
Persons who develop tuberculosis (TB) may have subtle immune defects that could predispose to other intracellular bacterial infections (ICBIs). We obtained data on TB and five ICBIs (Chlamydia trachomatis, Salmonella spp., Shigella spp., Yersinia spp., Listeria monocytogenes) reported to the Tennessee Department of Health, USA, 2000–2011. Incidence rate ratios (IRRs) comparing ICBIs in persons who developed TB and ICBIs in the Tennessee population, adjusted for age, sex, race and ethnicity were estimated. IRRs were not significantly elevated for all ICBIs combined [IRR 0·87, 95% confidence interval (CI) 0·71–1·06]. C. trachomatis rate was lowest in the year post-TB diagnosis (IRR 0·17, 95% CI 0·04–0·70). More Salmonella infections occurred in extrapulmonary TB compared to pulmonary TB patients (IRR 14·3, 95% CI 1·67–122); however, this appeared to be related to HIV co-infection. TB was not associated with an increased risk of other ICBIs. In fact, fewer C. trachomatis infections occurred after recent TB diagnosis. Reasons for this association, including reduced exposure, protection conferred by anti-TB drugs or macrophage activation by Mycobacterium tuberculosis infection warrant further investigation.
Common sources of shiga toxin-producing Escherichia coli (STEC) O157 infection have been identified by investigating outbreaks and by case-control studies of sporadic infections. We conducted an analysis to attribute STEC O157 infections ascertained in 1996 and 1999 by the Foodborne Diseases Active Surveillance Network (FoodNet) to sources. Multivariable models from two case-control studies conducted in FoodNet and outbreak investigations that occurred during the study years were used to calculate the annual number of infections attributable to six sources. Using the results of the outbreak investigations alone, 27% and 15% of infections were attributed to a source in 1996 and 1999, respectively. Combining information from both data sources, 65% of infections in 1996 and 34% of infections in 1999 were attributed. The results suggest that methods to incorporate data from multiple surveillance systems and over several years are needed to improve estimation of the number of illnesses attributable to exposure sources.
We will briefly review in situ synchrotron x-ray investigation of model thin film cathode systems for solid oxide fuel cells. The film cathodes examined in this study are (La,Sr)MnO3_δ (LSM), (La,Sr)CoO3_δ (LSC), and La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) thin films epitaxially grown on YSZ single crystal substrates by the pulse laser deposition technique. We find in all cases that Sr is enriched or segregated to the surface of the film cathodes. We concluded that the Sr enrichments or segregations are mainly the results of annealing because they do not depend on whether the cathodes are electrochemically biased or not during annealing. However, at least in the case of LSCF, we find that B-site Co segregates rather uniformly to the surface and the segregation responds sensitively and reversibly to the electrochemical bias.
To better understand the response of oxygen vacancy concentration to applied potential, the lattice parameter of pulsed laser deposited La0.6Sr0.4Co1-xFexO3-δ thin films was monitored using in situ X-ray diffraction. We demonstrate that the chemical expansion under applied potential depends on the cathode morphology, which determines the contribution of different reaction pathways. We investigated applied potential dependent lattice expansion on La0.6Sr0.4Co1-xFexO3-δ with 3 different Co:Fe ratios in an attempt to connect bulk chemical expansion data to thin films. We find that the chemical expansion trends in thin films are different than expected from bulk data.
Fishery independent indices of spawning biomass of Atlantic bluefin tuna in
western North Atlantic Ocean are presented which utilize National Marine
Fisheries Service ichthyoplankton survey data collected from 1977 through
2007 in the Gulf of Mexico. Indices were developed using similarly
standardized data from which previous indices were developed (i.e. abundance
of larvae with a first daily otolith increment formed per 100 m2 of
water sampled with bongo gear). Indices were also developed for the first
time from standardized data collected with neuston gear [i.e. abundance of
5-mm larvae (i.e. seven-day-old larvae) per 10 minute tow]. Indices of
larval abundance were developed using delta-lognormal models, including
following covariates: time of day, time of month, area sampled and year. Due
to the large frequency of zero catches during ichthyoplankton surveys, a
zero-inflated delta-lognormal approach was also used to develop indices.
Finally, a multivariate delta-lognormal approach was employed to develop
indices of annual abundance based on both bongo and neuston catches. The
results of these approaches were compared with one another and with other
indices of larval abundance previously developed for the Gulf of Mexico.
Residual analyses indicated that abundance indices of Atlantic bluefin tuna
larvae were more appropriately developed from bongo-collected data through
the zero-inflated delta-lognormal approach than other data sets and modeling
approaches. Also, when modeling bongo-collected data with the zero-inflated
delta-lognormal approach, the index values increased, indicating some
correction for zero-inflation, and their variability decreased as compared
to indices developed with the delta-lognormal approach.
Using a model cathode-electrolyte system composed of epitaxial thin-films of La1-xSrxMnO3-δ (LSM) on single crystal yttria-stabilized zirconia (YSZ), we investigated changes in the cation concentration profile in the LSM during heating and under applied potential using grazing incidence x-rays. Pulsed laser deposition (PLD) was used to grow epitaxial LSM(011) on YSZ(111). At room temperature, we find that Sr segregates to form Sr enriched nanoparticles and upon heating the sample to 700°C, Sr is slowly reincorporated into the film. We also find different amounts of Sr segregation as the X-ray beam is moved across the sample. The variation in the amount of Sr segregation is greater on the sample that has been subject to 72 hours of applied potential, suggesting that the electrochemistry plays a role in the Sr segregation.
The Northern Ireland beef herd currently incorporates a very diverse range of genotypes which produces a very varied product in terms of carcass weight, fatness and conformation (Kirkland et al., 2004). However, factors other than genotype may also influence the expression of maternal traits and progeny carcass characteristics. The objective of the present study was to evaluate the influence of dam conformation, irrespective of genotype, on dystocia and progeny carcass traits.
The suckler beef industry in Northern Ireland comprises many differing dam breeds and breed crosses. However, there is a paucity of data on the influence of dam breed on parameters such as carcass weight, fatness and conformation, and on factors affecting management of the herd (e.g. dystocia and fertility). The latter are particularly important in view of the increasing number of part time beef farmers in Northern Ireland. The objective of the present study was to evaluate the influence of dam breed on production characteristics of the suckler herd in Northern Ireland.
In the microcrystalline regime, the behavior of grain boundary-controlled electroceramics is well described by the “brick layer model” (BLM). In the nanocrystalline regime, however, grain boundary layers can represent a significant volume fraction of the overall microstructure and simple layer models are no longer valid. This work describes the development of a pixel-based finite-difference approach to treat a “nested cube model” (NCM), which more accurately calculates the current distribution in polycrystalline ceramics when grain core and grain boundary dimensions become comparable. Furthermore, the NCM approaches layer model behavior as the volume fraction of grain cores approaches unity (thin boundary layers) and it matches standard effective medium treatments as the volume fraction of grain cores approaches zero. Therefore, the NCM can model electroceramic behavior at all grain sizes, from nanoscale to microscale. It can also be modified to handle multi-layer grain boundaries and property gradient effects (e.g., due to space charge regions).
To estimate the extent of, and evaluate risk factors for, elevated carboxyhemoglobin levels among patients undergoing general anesthesia and to identify the source of carbon monoxide.
Matched case-control study to measure carboxyhemoglobin levels.
Large academic medical center.
45 surgical patients who underwent general anesthesia.
Case-patients were more likely than controls to undergo surgery on Monday or Tuesday (10/15 vs 7/30; matched odds ratio [mOR], 7.7; 95% confidence interval [CI95], 1.8-34; P=.01), in one particular room (7/15 vs 4/30; mOR, 8.5; CI95, 1.5-48; P=.03) or in a room that was idle for ≥24 hours (11/15 vs 1/30; mOR, 95.5; CI95, 8.0-1,138; P≤.001). In a multivariate model, only rooms, and hence the anesthesia equipment, that were idle for ≥24 hours were independently associated with elevated intraoperative carboxyhemoglobin levels (OR, 22.4; CI95, 1.5-338; P=.025). Moreover, peak carboxyhemoglobin levels were correlated with the length of time that the room was idle (r=0.7; CI95, 0.3-0.9). Carbon monoxide was detected in the anesthesia machine outflow during one case-procedure. No contamination of anesthesia gas supplies or CO2 absorbents was found.
Carbon monoxide may accumulate in anesthesia circuits left idle for ≥24 hours as a result of a chemical interaction between CO2-absorbent granules and anesthetic gases. Patients administered anesthesia through such circuits may be at increased risk for elevated carboxyhemoglobin levels during surgery or the early postoperative period.
Although food handlers are often implicated as the source of infection
in outbreaks of
food-borne viral gastroenteritis, little is known about the
timing of infectivity in relation to illness.
We investigated a gastroenteritis outbreak among employees of a manufacturing
found an association (RR=14·1, 95% CI=2·0–97·3)
between disease and eating sandwiches
prepared by 6 food handlers, 1 of whom reported gastroenteritis which had
subsided 4 days
earlier. Norwalk-like viruses were detected by electron microscopy or reverse
transcriptase-polymerase chain reaction (RT-PCR) in stool specimens from several company
sick food handler whose specimen was obtained 10 days after resolution
of illness, and an
asymptomatic food handler. All RT-PCR product sequences were identical,
common source of infection. These data support observations from recent
that current recommendations to exclude food handlers from work for 48–72
h after recovery
from illness may not always prevent transmission of Norwalk-like viruses
because virus can be
shed up to 10 days after illness or while exhibiting no symptoms.
Angiolympoid hyperplasia with cosinophilia is a rare benign condition that causes swellings in the head and neck. It is difficult to diagnose prior to biopsy and is frequently mistaken for a malignant tumoour. A case involving a 21-year-old man who presented with a 2 cm diameter fiborous lesion the subcutaneous tissue of the cheek is reported. The clinical and histological features are reviewed and the differences between this condition and the similar condition of Kimura's disease are discussed. Initial treatment with intralesional or sustemic steroids is suggested as this may avoid the need for excision.
Complete conductivity spectra have been taken of a lithium ion conducting glass of composition B2O3 · 0.56Li2O · 0.45LiBr and of lithium stabilized Na-β″-alumina, at various temperatures. — In the glass, it has forthe first time been possible to separate the hopping and vibrational contributions to theconductivity. The resulting hopping conductivity spectra display high-frequency plateaux similar to those known to exist in crystalline solid electrolytes like RbAg415 and Na-β-alumina. In the dispersive regime, the spectra are characterized bytwo different power-law exponents, p = 0.6 and q = 1.3. The data are evaluated by combined application of the jump relaxation model and the dynamic structure model. — Na-β″-alumina has pronounced high-frequency plateaux between about 200 GHz and 400 GHz. The hopping observed in the spectra can be decomposed into hops that are a priori unsuccessful and others that can be treated in terms of the jump relaxation model. The latter fraction is found to increase with increasing temperature.
Beusani is a rice crop management system practised in rainfed lowland areas of eastern India whereby rice is dry-seeded, then wet-ploughed at 30–50 days after emergence and the land levelled by drawing a board across the field. Field experiments showed that beusani enhances rooting, especially in shallow soil layers, as a result of reduced penetration resistance. Although beusani reduced weed biomass by 38%, it was not as effective as application of herbicide followed by hand weeding, which reduced biomass by 87%. Yields were directly related to weed control, so beusani treatments did not yield as much as the herbicide plus hand weeding treatments in these experiments.