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Phasmarhabditis hermaphrodita is a parasitic nematode of terrestrial gastropods that has been formulated into a biological control agent for farmers and gardeners to kill slugs and snails. In order to locate slugs it is attracted to mucus, faeces and volatile cues; however, there is no information about whether these nematodes are attracted to snail cues. It is also unknown how wild isolates of P. hermaphrodita or different Phasmarhabditis species behave when exposed to gastropod cues. Therefore, we investigated whether P. hermaphrodita (commercial and wild isolated strains), P. neopapillosa and P. californica were attracted to mucus from several common snail species (Cepaea nemoralis, Cepaea hortensis, Arianta arbustorum and Cornu aspersum). We also examined whether snails (C. aspersum) collected from different locations around the UK differed in their attractiveness to wild isolates of P. hermaphrodita. Furthermore, we also investigated what properties of snail mucus the nematodes were attracted to, including hyaluronic acid and metal salts (FeSO4, ZnSO4, CuSO4 and MgSO4). We found that the commercial strain of P. hermaphrodita responded poorly to snail mucus compared to wild isolated strains, and C. aspersum collected from different parts of the UK differed in their attractiveness to the nematodes. We found that Phasmarhabditis nematodes were weakly attracted to all metals tested but were strongly attracted to hyaluronic acid. In a final experiment we also showed that pharmacological manipulation of cyclic guanosine monophosphate (cGMP) increased chemoattraction to snail mucus, suggesting that the protein kinase EGL-4 may be responsible for Phasmarhabditis sp. chemoattraction.
To assess whether pre-operative assessment with a bone conduction hearing device on a softband is an accurate predictor of performance with one of two transcutaneous hearing implants.
Cohort study comparing pre-and post-operative speech audiometry using correlation analysis.
Pre-operative pure tone audiometry and aided half optimum speech recognition thresholds were compared with post-operative aided results for each ear that had undergone implantation. Data were collected prospectively.
Full data were available in 24 ears. In 19 out of 24 ears (79 per cent), the difference between pre- and post-operative speech scores was less than 10 dB, demonstrating a good clinical correlation. The Pearson correlation coefficient was calculated at 0.66 (95 per cent confidence interval = 0.357–0.842), indicating a strong statistical correlation.
Pre-operative softband testing shows good clinical correlation and strong statistical correlation with hearing implant performance. The findings suggest there is value in using the test to predict performance and guide patients’ expectations.
The genetic mechanisms of how free-living nematodes evolved into parasites are unknown. Current genetic model nematodes (e.g. Caenorhabditis elegans) are not well suited to provide the answer, and mammalian parasites are expensive and logistically difficult to maintain. Here we propose the terrestrial gastropod parasite Phasmarhabditis hermaphrodita as a new alternative to study the evolution of parasitism, and outline the methodology of how to keep P. hermaphrodita in the lab for genetic experiments. We show that P. hermaphrodita (and several other Phasmarhabditis species) are easy to isolate and identify from slugs and snails from around the UK. We outline how to make isogenic lines using ‘semi-natural’ conditions to reduce in-lab evolution, and how to optimize growth using nematode growth media (NGM) agar and naturally isolated bacteria. We show that P. hermaphrodita is amenable to forward genetics and that unc and sma mutants can be generated using formaldehyde mutagenesis. We also detail the procedures needed to carry out genetic crosses. Furthermore, we show natural variation within our Phasmarhabditis collection, with isolates displaying differences in survival when exposed to high temperatures and pH, which facilitates micro and macro evolutionary studies. In summary, we believe that this genetically amenable parasite that shares many attributes with C. elegans as well as being in Clade 5, which contains many animal, plant and arthropod parasites, could be an excellent model to understand the genetic basis of parasitism in the Nematoda.
Our aim was to outline a procedure for obtaining a rapid autopsy in order to collect high-quality postmortem tissue for genomic analysis.
This report details a bi-institutional collaborative effort to coordinate a rapid autopsy for a pediatric patient who had died at home. We discuss the scientific rationale for offering a rapid autopsy to caregivers of pediatric patients as well as parental perspectives on broaching the subject of autopsy. We then review the logistics and coordination involved with planning a rapid autopsy and the sequence of events needed to maximize tissue quality.
We report the successful coordination of a rapid autopsy for a patient who died in a hospice setting at her out-of-state home. The time interval from death to the start of the rapid autopsy procedure was 4.5 hours, despite the logistical considerations demanded by the location of the patient. Tumor aliquots and nonneoplastic tissues were successfully snap frozen for downstream genomic studies.
Significance of Results:
Physicians should consider trialing a rapid autopsy program at their institution that could be offered to caregivers of pediatric patients. This case report offers a framework to help clinicians develop their own rapid autopsy programs as well as guidelines to help streamline this process for appropriate candidates going forward.
The synthesis and texturization processes of fluorinated surfaces by means of atmospheric plasma are investigated and presented through an integrated study of both the plasma phase and the resulting material surface. Three methods enhancing the surface hydrophobicity up to the production of super-hydrophobic surfaces are evaluated: (i) the modification of a polytetrafluoroethylene (PTFE) surface, (ii) the plasma deposition of fluorinated coatings and (iii) the incorporation of nanoparticles into those fluorinated films. In all the approaches, the nature of the plasma gas appears to be a crucial parameter for the desired property. Although a higher etching of the PTFE surface can be obtained with a pure helium plasma, the texturization can only be created if O2 is added to the plasma, which simultaneously decreases the total etching. The deposition of CxFy films by a dielectric barrier discharge leads to hydrophobic coatings with water contact angles (WCAs) of 115°, but only the filamentary argon discharge induces higher WCAs. Finally, nanoparticles were deposited under the fluorinated layer to increase the surface roughness and therefore produce super-hydrophobic hybrid coatings characterized by the nonadherence of the water droplet at the surface.
Nanomechanical resonators made from silicon nitride with residual stress is actuated using dielectric field gradient force. Doubly clamped nanomechanical resonators are made from SiNx-SiO2-Si tri-layer substrate and DC electric field induces a temporary dipole moment while a small AC electric field drives beam resonator by dielectric force. Realized nanomechanical resonators show resonant motion of high resonant frequency (up to ~31 Mhz) and mechanical quality factor up to over 48,000 at room temperature and moderate vacuum condition. From the FEA (Finite Element Analysis) of resonant motion, doubly clamped resonator shows torsional motion and in-plane motion which can be assigned to additional multiple modes in resonant response measurement
The general paraxial particle-optic properties of the hexapole field are summarized and lens formulae derived. Formulae are given for the transmission as a function of particle velocity and system geometry for geometries appropriate to the case of neutral atom beams and of slow neutron beams respectively. These formulae are used to evaluate the hexapole magnet as a velocity selector and polarizer for atomic beams and as a spin polarizer for neutron beams. Some experimental observations on potassium beams are quoted in support of the theory.
Three enzyme immunoassays were used for the serodiagnosis of Trypanosoma evansi in camels in the Sudan in order to evaluate their ability to discriminate between infected and non-infected animals. Two assays were used for the detection of trypanosomal antibodies, one using specific anti-camel IgG conjugate and another using a non-specific Protein A conjugate. The third assay detected the presence of trypanosomal antigens using anti-T. evansi antibodies in a double antibody sandwich assay. Inspection of the frequency distribution of assay results suggested that the ELISA for circulating trypanosomal antibodies using specific antisera and the ELISA for circulating antigens can distinguish between non-infected camels and infected camels exhibiting patent infections or not. The ELISA using Protein A conjugate to bind non-specifically to camel immunoglobulin did not appear to discriminate between infected and non-infected animals.
This paper was written at the request of the Life Research Committee of the United Kingdom Actuarial Profession's Life Board. It concerns the valuation of U.K. with-profits business, with particular attention to the market-consistent ‘realistic reporting’ basis currently being used in the U.K. by the regulator, the Financial Services Authority (FSA). The paper surveys recent regulatory activity concerning the development and introduction of the new valuation approach, and puts it into the context of a survey of alternative methodologies, both deterministic and stochastic. The particular issues arising when considering prudential solvency are discussed, and various approaches are reviewed and compared with market consistent methods. Numerical examples are given, which demonstrate potential issues (regarding comparability and consistency) with the FSA's proposed approach — in particular the sensitivity of results to model calibration. The authors support the FSA's move to a stochastically-based framework for solvency measurement, but highlight some issues which need to be taken into account.
The UK Food Standards Agency convened a group of expert scientists to review current research investigating emerging diet-related surrogate end points for colorectal cancer (CRC). The workshop aimed to overview current research and establish priorities for future research. The workshop considered that the validation of current putative diet-related surrogate end points for CRC and the development of novel ones, particularly in the emerging fields of proteomics, genomics and epigenomics, should be a high priority for future research.
The prevalence and incidence of Trypanosoma evansi infections in village buffaloes in Central
Java were estimated using parasitological tests, two antigen-detection ELISAs (2G6 Ag-ELISA
and Tr7 Ag-ELISA), an antibody-detection ELISA (IgG ELISA) and a card agglutination test
(CATT). Of 2387 village buffaloes tested in five districts, 4% (95% confidence interval [CI]:
3%, 5%) were positive with the microhaematocrit test (MHCT), 58% (95% CI: 56%, 60%)
were positive with the 2G6 Ag-ELISA and 70% (95% CI: 68%, 72%) were positive with the
Tr7 Ag-ELISA. An increasing prevalence with age was found and the proportion of positive
buffaloes was highest in the over 84 months-old age-group (68%) with the 2G6 Ag-ELISA and
in the 37–60 months-old age-group (78%) with the Tr7 Ag-ELISA. Parasitaemic buffaloes were
found in more than half of the villages visited. Corrected village-specific prevalence values
obtained with the two Ag-ELISAs ranged from 0% to over 100%, and prevalence differed
significantly (P[les ]0·0001) between villages in four of the five districts. Overall, 10% of
buffaloes tested in markets were found to be parasitaemic and 39, 56 and 47% were found
positive with the 2G6 Ag-ELISA, IgG ELISA and CATT, respectively. Incidence rates varied
according to the test used and ranged from 0·22 (95% CI: 0·09, 0·44)
to 0·44 (95% CI: 0·24, 0·76), per animal-year at risk,
in two villages. The results highlight the importance of using
validated diagnostic tests to obtain accurate estimates of prevalence and incidence. These
parameters are needed, for example in mathematical models, for the development and
evaluation of different control strategies for T. evansi infections in buffaloes.
In order to prescribe appropriate analgesia for burns dressing changes the pain experienced by 30 burned patients during this procedure was recorded. Patients received analgesia prior to their dressing changes according to the current protocol in the burns unit. During the same period the medical and nursing staff in the unit who were involved in prescribing and administering the analgesia for the dressing change, were asked to assess the severity of pain that they thought patients experienced during dressing changes. Patients recorded their worst pain as none or mild in 64% of procedures. In contrast, no surgeon and only one nurse, rated pain as none or mild. The discrepancy between severity of pain recorded by patients and the pain predicted by staff prescribing and administering analgesia has clinical implications.
Two Ag-ELISAs, an IgG-specific antibody detection ELISA (IgG ELISA) and a card
agglutination test (CATT) for the detection of Trypanasoma evansi infections in buffaloes in
Indonesia, were compared. Diagnostic sensitivity estimates were obtained by testing sera from
139 Indonesian buffaloes which had been found to be infected by parasitological tests.
Diagnostic specificity was estimated by testing sera from 263 buffaloes living in Australia.
Response-operating characteristic curves were constructed, and optimal ELISA cut-off values,
which minimized the number of false–negative and false–positive results, were chosen. The IgG
ELISA had the highest sensitivity (89%) and the CATT had the highest specificity (100%).
There was a significant difference between the sensitivities (71 and 81%), but not between the
specificities (75 and 78%), of the two Ag-ELISAs. The four tests were further compared by
calculation of post-test probabilities of infection for positive and negative test results using a
range of prevalence values, and likelihood ratios. The results suggested that the CATT was the
best test to ‘rule-in’ infection (i.e. the highest probability of infection in test-positive animals)
and the IgG ELISA was the best test to ‘rule-out’ infection (i.e. the lowest probability of
infection in test-negative animals).
Western blot analysis using an anti-globin rabbit serum Rb94 revealed a major band of 17 kDa in extracts of Ostertagia ostertagi adults and 4th-stage larvae. The adult stage globin-like antigen (OoAdGlb) was purified from total worm extracts by liquid chromatography. The protein has an estimated molecular mass of 36 kDa under non-reducing conditions, suggesting a dimeric structure containing 2 non-covalently linked 17 kDa monomers. Tryptic peptides were sequenced and showed strong similarities with the globins of free-living and parasitic nematodes. Immunolocalization revealed the presence of this globin-like antigen in the body wall musculature and/or the cuticle of O. ostertagi adults. An enzyme-linked immunosorbent assay based on the purified OoAdGlb showed no differences in response between calves infected by O. ostertagi and/or Cooperia oncophora and the negative controls.
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