10,092 research outputs found
Parasite to patient: A quantitative risk model for Trichinella spp. in pork and wild boar meat
No full textAbstractConsumption of raw or inadequately cooked pork meat may result in trichinellosis, a human disease due to nematodes of the genus Trichinella. In many countries worldwide, individual control of pig carcasses at meat inspection is mandatory but incurs high costs in relation to absence of positive carcasses from pigs reared under controlled housing. EU regulation 2015/1375 implements an alternative risk-based approach, in view of absence of positive findings in pigs under controlled housing conditions. Moreover, Codex Alimentarius guidelines for the control of Trichinella spp. in meat of suidae have been published (CAC, 2015) and used in conjunction with the OIE terrestrial Animal health code, to provide guidance to governments and industry on risk based control measures to prevent human exposure to Trichinella spp. and to facilitate international pork trade.To further support such a risk-based approach, we model the risk of human trichinellosis due to consumption of meat from infected pigs, raised under non-controlled housing and wild boar, using Quantitative Microbial Risk Assessment (QMRA) methods. Our model quantifies the distribution of Trichinella muscle larve (ML) in swine, test sensitivity at carcass control, partitioning of edible pork parts, Trichinella ML distribution in edible muscle types, heat inactivation by cooking and portion sizes. The resulting exposure estimate is combined with a dose response model for Trichinella species to estimate the incidence of human illness after consumption of infected meat. Paramater estimation is based on experimental and observational datasets.In Poland, which served as example, we estimated an average incidence of 0.90 (95%CI: 0.00–3.68) trichinellosis cases per million persons per year (Mpy) due to consumption of pork from pigs that were reared under non-controlled housing, and 1.97 (95%CI: 0.82–4.00) cases per Mpy due to consumption of wild boar.The total estimated incidence of human trichinellosis attributed to pigs from non-controlled housing and wild boar in Poland, is similar to the incidence of human trichinellosis in that country reported by EFSA. Overall, in Europe, we estimated an upper incidence limit of 5.3×10−4 cases per Mpy, or less than one predicted case of trichinellosis in the European Union every 4years, due to consumption of pork from controlled housing. Therefore, Trichinella testing of pigs under controlled housing is not adding any value to protect human health. We suggest applying our farm-to-fork QMRA model to further support decision making on the global scale
Ethnobotanical investigation of 'wild' food plants used by rice farmers in Kalasin, Northeast Thailand
No full textAbstract Background Wild food plants are a critical component in the subsistence system of rice farmers in Northeast Thailand. One of the important characteristics of wild plant foods among farming households is that the main collection locations are increasingly from anthropogenic ecosystems such as agricultural areas rather than pristine ecosystems. This paper provides selected results from a study of wild food conducted in several villages in Northeast Thailand. A complete botanical inventory of wild food plants from these communities and surrounding areas is provided including their diversity of growth forms, the different anthropogenic locations were these species grow and the multiplicity of uses they have. Methods Data was collected using focus groups and key informant interviews with women locally recognized as knowledgeable about contemporarily gathered plants. Plant species were identified by local taxonomists. Results A total of 87 wild food plants, belonging to 47 families were reported, mainly trees, herbs (terrestrial and aquatic) and climbers. Rice fields constitute the most important growth location where 70% of the plants are found, followed by secondary woody areas and home gardens. The majority of species (80%) can be found in multiple growth locations, which is partly explained by villagers moving selected species from one place to another and engaging in different degrees of management. Wild food plants have multiple edible parts varying from reproductive structures to vegetative organs. More than two thirds of species are reported as having diverse additional uses and more than half of them are also regarded as medicine. Conclusions This study shows the remarkable importance of anthropogenic areas in providing wild food plants. This is reflected in the great diversity of species found, contributing to the food and nutritional security of rice farmers in Northeast Thailand.</p
Competition between wild and captive-bred Penaeus plebejus and implications for stock enhancement
No full textThe mechanisms that drive density dependence are rarely studied in the applied context of population management. We examined the potential for competition for food and shelter and the resulting demographic density dependence to influence how well populations of the eastern king prawn Penaeus plebejus Hess can recover following marine stock enhancement programmes in which captive-bred juveniles are released into the wild. Specifically, manipulative laboratory experiments were used to quantify the differential effects of competition for food and competition for shelter on survival of wild and captive-bred P. plebejus as densities were increased and as each category of P. plebejus (wild or captive-bred) was supplemented with the alternate category. Increasing population densities when food and shelter were limited lowered survival for both categories. When food was limited, survival of both categories was unaffected by addition of the alternative category. Adding wild P. plebejus to their captive-bred counterparts when shelter was limited under laboratory conditions resulted in significantly higher mortality in captive-bred individuals. In contrast, adding captive-bred P. plebejus to wild individuals under these conditions did not affect wild P. plebejus. We conclude that if the current results can be extended to wild conditions, competition for shelter may lead to the loss of captive-bred P. plebejus, thereby reducing the intended outcomes of stock enhancement. This highlights the importance of investigating interactions between wild and captive-bred animals prior to stock enhancement to predict long-term outcomes and identify situations where stock enhancement could be an effective response to the loss of populations or recruitment limitation
Lipid levels in polycystic ovary syndrome: systematic review and meta-analysis
No full textObjective: To quantify the magnitude and pattern of low-density lipoprotein (LDL) cholesterol and nonhigh-density lipoprotein (HDL) cholesterol levels in women with polycystic ovary syndrome (PCOS) versus control women. Design: Systematic review and meta-analysis of lipid levels in published cross-sectional studies worldwide where PCOS women and controls were examined and sampled. Main Outcome Measure(s): Differences in plasma lipids (including triglycerides, HDL-cholesterol, LDL-cholesterol, and nonHDL-cholesterol) in PCOS versus control subjects were calculated. Comparisons were made with and without body mass index (BMI) matching. Result(s): Triglyceride levels were 26 mg/dL (95% confidence interval [CI] 17-35) higher and HDL-cholesterol concentrations 6 mg/dL (95% CI 4-9) lower in women with PCOS. Also, LDL-cholesterol and nonHDL-cholesterol concentrations were higher in PCOS: by 12 mg/dL (95% CI 10-16) and 19 mg/dL (95% CI 16-22), respectively. With BMI matching, LDL-cholesterol and nonHDL-cholesterol were still higher in PCOS: by 9 mg/dL (95% CI 6-12) and 16 mg/dL (95% CI 14-19), respectively. LDL-cholesterol and nonHDL-cholesterol differences were greater with National Institutes of Health criteria [15 mg/dL (95% CI 13-17) and 21 mg/dL (95% CI 16-25), respectively] versus Rotterdam criteria [8 mg/dL (95% CI 5-12) and 17 (95% CI 13-22), respectively]. Conclusion(s): Dyslipidemia is common in PCOS. Beyond known alterations in triglycerides and HDL-cholesterol, women with PCOS have higher LDL-cholesterol and nonHDL-cholesterol, regardless of BMI. We recommend that all women with PCOS be screened for dyslipidemia, including LDL-cholesterol and nonHDL-cholesterol determinations, for effective cardiovascular risk preventio
A genetic analysis of the introgression process from cultivated lettuce (Lactuca sativa L.) to wild prickly lettuce (L. serriola L.)
No full text Many plant species can hybridise and produce fertile offspring. Hybridization between cultivated species and their wild relatives has raised concerns with regard to GM crops, as it constitutes a possible route along which the transgene could disperse from crops into related wild species, establish itself in the natural population, and persist under natural conditions. This may cause unintended ecological consequences such as the formation of more invasive weeds and genetic erosion. After crop-wild hybridization, the persistence of the hybrids and of the crop genes (including the transgenes) in later generations depends on their genetic make-up, which consists of specific combinations of wild and crop genomic segments, and on the environmental conditions. Therefore, knowledge on the dynamics of crop-wild hybridization and introgression using conventional crop varieties is needed as it constitutes the baseline for putting into perspective the effects of transgene introgression under natural conditions. This study focused on understanding the genetic process of hybridization and introgression from cultivated to wild relative species using cultivated lettuce (Lactuca sativa L.) and its closest wild relative, prickly lettuce (L. serriola L.) as a crop-wild complex model. Natural populations of prickly lettuce in Europe were tested for the occurrence of crop-wild hybrids using Bayesian-based programmes (Structure, InStruct and NewHybrids) which returned a crop-wild hybrid occurrence of 7%. However, the geographical location of the hybrids led to the conclusion that crop-wild hybridization is not the cause of the recent northward spread of L. serriola in Europe. To test for the importance of the crop genomic segments to the performance of lettuce crop-wild hybrids, three hybrid generations were created (F2 as a selfing generation, and BC1 and BC2, backcrossed to the wild genotype to mimick the introgression process) by crossing L. sativa (cv. Dynamite) with L. serriola collected from Eys (the Netherlands). The three populations were genotyped with Single Nucleotide Polymorphism markers for genetic analysis. Because of the importance of the abiotic stresses as selection factors under natural conditions and the prospective of generating GM crop varieties with enhanced abiotic stress tolerance, the three populations were evaluated for vigour at the rosette stage under greenhouse conditions of non-stress, drought, salinity and nutrient deficiency. The BC1 population was also evaluated under field conditions at two locations (Wageningen and Sijbekarspel, the Netherlands) for hybrid germination, vigour, survival and reproduction. Based on the location and allelic effect of the QTLs for germination, vigour, survival and reproductive traits in the current lettuce crop-wild cross, genomic regions were suggested where transgenes could be or could not be located in order to mitigate their persistence in crop-wild hybrids through genetic hitchhiking and background selection. </p
Hepatitis E Virus in Farmed Rabbits, Wild Rabbits and Petting Farm Rabbits in the Netherlands
No full textRabbits have been suggested as a zoonotic source of Hepatitis E virus. Phylogenetic analysis of HEV isolates from farmed, wild and pet rabbits in the Netherlands (23, 0, and 60 % respectively) showed them to be grouped amongst published rabbit HEV sequences and distinct from most human isolates. Dutch rabbits are unlikely to be a zoonotic source.</p
First GIS Analysis of Modern Stone Tools Used by Wild Chimpanzees (Pan troglodytes verus) in Bossou, Guinea, West Africa
No full textStone tool use by wild chimpanzees of West Africa offers a unique opportunity to explore the evolutionary roots of technology during human evolution. However, detailed analyses of chimpanzee stone artifacts are still lacking, thus precluding a comparison with the earliest archaeological record. This paper presents the first systematic study of stone tools used by wild chimpanzees to crack open nuts in Bossou (Guinea-Conakry), and applies pioneering analytical techniques to such artifacts. Automatic morphometric GIS classification enabled to create maps of use wear over the stone tools (anvils, hammers, and hammers/ anvils), which were blind tested with GIS spatial analysis of damage patterns identified visually. Our analysis shows that chimpanzee stone tool use wear can be systematized and specific damage patterns discerned, allowing to discriminate between active and passive pounders in lithic assemblages. In summary, our results demonstrate the heuristic potential of combined suites of GIS techniques for the analysis of battered artifacts, and have enabled creating a referential framework of analysis in which wild chimpanzee battered tools can for the first time be directly compared to the early archaeological record
Rayleigh number dependence of the Archimedes number dependent large-scale flow structure formation in mixed convection
No full textWe report on experimental investigations of large-scale flow structure formation in mixed convection. We characterize the flow field by measuring the velocity fields within a rectangular model room using 2D2C PIV. The control parameters are the Reynolds number Re, the Rayleigh number Ra and the Prandtl number Pr. All parameters are linked through the Archimedes number Ar. In 6.4x10-2 ≤ Ar ≤ 1.39x101, 4.2x103 ≤ Re ≤ 6.35x104 and Ra = 3.1x107, Ra = 1.8x108 and Pr = 0.713 we found flow 3 different flow structures. While keeping Ra and Pr constant and varying Ar through Re variations, we found an Ar dependence of the largescale flow structure formation within 6.4x10-2 ≤ Ar ≤ 1.39x101. Furthermore, we found a Ra dependence of the structure formation, which shifts the transition points between the structures to higher Archimedes numbers and reduces the mean velocities within the investigated domain
RA upregulates DC TLR5 expression.
No full text<p>BMDCs were generated in the absence (Ctrl-DC) or presence of 1 µM RA (RA-DC) from day 3 of an 8-day culture. Control DC and RA-DC TLR5 expression was determined by quantitative real-time PCR (<b>a</b>) and by flow cytometry shown as histogram (<b>b</b>; shaded histogram, control DCs; solid line, RA-DCs) or as aggregate data (<b>c</b>). Bar charts represent aggregate data with mean ± SEM of three experiments (a, c; *<i>P</i><0.05; compared to control DC). Flow cytometry data (b) is representative of three individual experiments. One wild type mouse for each experiment.</p
The surveillance and risk assessment of wild birds in northern Australia for highly pathogenic avian influenza H5N1 virus
No full textHighly pathogenic avian influenza (HPAI), caused by infection with H5N1 virus, is a transboundary disease which has had a significant socio-economic impact on the poultry production systems of Eurasia, and spillover events with mortality in humans and wild birds. In northern Australia, prior to the current study there was poor understanding of the ecology of avian influenza viruses (AIV) and the risks of H5N1 transmission by wild birds. In this study, the biological pathways of risk for HPAI H5N1 by migratory birds were estimated as a negligible to very low risk to the wild birds of northern Australia. Following stochastic modelling the highest mean frequency of outbreaks was 1 year in 36 years (range 1 in 25-53 years; annual incidence of 0.028) for the Little Curlew (Numenius minutus), followed by the Sharp-tailed Sandpiper (Calidris acuminata) (1 in 56 years, range 36 to 91 years).
Three species of wild birds were challenged with a H6N2 low pathogenicity AIV (LPAIV). There was poor viral replication in the Ruddy Turnstones (Arenaria interpres) and Silver Gulls (Chroicocephalus novaehollandiae) with mostly low titre oropharyngeal (OP) excretion [median titre at 4 days post inoculation (DPI) of 101.43 and 102.09 50% embryo infectious dose (EID50)/0.1 mL respectively], with the exception of an OP sample from one Silver Gull (104.26 EID50/0.1 mL at 2 DPI), and one cloacal sample from a Ruddy Turnstone (103.14 EID50/0.1 mL at 10 DPI). In the Wandering Whistling Ducks (Dendrocygna arcuata), there was gastro-intestinal tropism with moderately high titre viral excretion to 6 DPI (highest median titre of 104.58 EID50/0.1 mL in cloacal swabs at 4 DPI). The anti-haemagglutinin (HA) antibody response was poor in the ducks and declined from 19-56 DPI [highest haemagglutination inhibition (HI) test reciprocal geometric mean titre (GMT) of 16.1 at 19 DPI to a GMT of 3.7 at 56 DPI]. In the ducks after 42 DPI, nucleoprotein (NP) c-ELISA antibodies waned slowly from a median of 81% inhibition, and were long-lived to at least 8 months with a 57% median inhibition value.
The evaluation of a commercial NP c-ELISA, HI test, Taqman Type A RRT-PCR and embryonating chicken egg (ECE) virus isolation methods suggests high validity of these tests in wild birds, comparable to that reported in poultry. The NP c-ELISA in high AIV prevalence situations had a 100% diagnostic sensitivity (95% CI 81.5, 100) and in controls had 91% diagnostic specificity (95% CI 70.8, 98.9). In low AIV prevalence situations using a ≥60% inhibition threshold for positivity relative to the HI test, c-ELISA performed with 90.5% diagnostic sensitivity (95% CI 86.2, 93.8) and 41.2% diagnostic specificity (95% CI 38.1, 44.5). Assessment of the HI test suggests that a titre of ≥8 is a significant result in wild birds, and using this titre the HI test had 83.3% diagnostic sensitivity (95% CI 58.6, 96.4) in the challenged birds. The Type A RRT-PCR test performance for cloacal swabs had high diagnostic sensitivity that varied between 83.3-100% and diagnostic specificity that varied between 94.1-100% over 2-6 DPI when evaluated against ECE virus isolation, with substantial to outstanding agreement (Kappa statistic=0.8) and significant positive correlation (rs=0.82). The recommended thresholds for the Type A RRT-PCR at the Australian Animal Health Laboratory (AAHL) in poultry of CT <37 for positivity with an intermediate threshold (CT 37-40) were found to be valid in wild birds. The ECE virus isolation method performed well with 89% of virus positive birds positive on the first passage
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