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 firstname.lastname@example.org
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.
Lymphatic filariasis (LF) threatens nearly 20% of the world's population and has handicapped one-third of the 120 million people currently infected. Current control and elimination programs for LF rely on mass drug administration of albendazole plus diethylcarbamazine (DEC) or ivermectin. Only the mechanism of action of albendazole is well understood. To gain a better insight into antifilarial drug action in vivo, we treated gerbils harbouring patent Brugia malayi infections with 6 mg kg−1 DEC, 0.15 mg kg−1 ivermectin or 1 mg kg−1 albendazole. Treatments had no effect on the numbers of worms present in the peritoneal cavity of treated animals, so effects on gene expression were a direct result of the drug and not complicated by dying parasites. Adults and microfilariae were collected 1 and 7 days post-treatment and RNA isolated for transcriptomic analysis. The experiment was repeated three times. Ivermectin treatment produced the most differentially expressed genes (DEGs), 113. DEC treatment yielded 61 DEGs. Albendazole treatment resulted in little change in gene expression, with only 6 genes affected. In total, nearly 200 DEGs were identified with little overlap between treatment groups, suggesting that these drugs may interfere in different ways with processes important for parasite survival, development, and reproduction.
Lymphatic filariasis is a neglected tropical disease caused by roundworm parasites such as Brugia malayi that spread via a mosquito vector. In vitro culture of these parasites provides controlled conditions to understand parasite biology and provides a cheaper way to screen potential micro- and macrofilaricides. Published studies have used a wide array of approaches and metrics regarding in vitro cultures of B. malayi; as a result, drawing comparisons and identifying the reasons why inability to reproduce outcomes are difficult. This study sought to determine conditions that ensure reproducible outcomes and used evaluation metrics that are easily measured and can be automated to ensure objectivity. We found culturing B. malayi third-stage larvae (L3) in endothelial basal media supplemented with 20% fetal bovine serum and 75 µm ascorbic acid in a temperature- and humidity-controlled incubator produced better survival and molting rates as well as longer and more motile parasites than previously reported. The benefit of ascorbic acid seemed to be unique to L3 parasites, as the addition of ascorbic acid to adult parasites had no significant impact on survival or motility. The methods reported in this study will help in designing experiments for both parasite behaviour studies and drug screening applications for disease eradication.
For most producers, unmanned aerial vehicles (UAV) are a novelty that has been little employed in their agricultural operations. An UAV will not fix every problem on the farm, but there are some practical applications for which UAVs have demonstrated value. Three examples of how UAVs have been used in weed science applications are presented here; the methods are transferable to other agricultural commodities with similar characteristics. The first of these is quantification of the extent and severity of non-target herbicide injury. The second application is calculation of spray thresholds based on weed populations. The third application is development of site-specific herbicide treatment.
Prevention of heartworm disease caused by Dirofilaria immitis in domestic dogs and cats relies on a single drug class, the macrocyclic lactones (MLs). Recently, it has been demonstrated that ML-resistant D. immitis are circulating in the Mississippi Delta region of the USA, but the prevalence and impact of these resistant parasites remains unknown. We review published studies that demonstrated resistance in D.immitis, along with our current understanding of its mechanisms. Efforts to develop in vitro tests for resistance have not yet yielded a suitable assay, so testing infected animals for microfilariae that persist in the face of ML treatment may be the best current option. Since the vast majority of D. immitis populations continue to be drug-sensitive, protected dogs are likely to be infected with only a few parasites and experience relatively mild disease. In cats, infection with small numbers of worms can cause severe disease and so the clinical consequences of drug resistance may be more severe. Since melarsomine dihydrochloride, the drug used to remove adult worms, is not an ML, the ML-resistance should have no impact on our ability to treat diseased animals. A large refugium of heartworms that are not exposed to drugs exists in unprotected dogs and in wild canids, which may limit the development and spread of resistance alleles.
Multiple salmonellosis outbreaks have been linked to contaminated tomatoes. We investigated a multistate outbreak of Salmonella Typhimurium infections among 190 cases. For hypothesis generation, review of patients' food histories from four restaurant-associated clusters in four states revealed that large tomatoes were the only common food consumed by patients. Two case-control studies were conducted to identify food exposures associated with infections. In a study conducted in nine states illness was significantly associated with eating raw, large, round tomatoes in a restaurant [matched odds ratio (mOR) 3·1, 95% confidence interval (CI) 1·3–7·3]. In a Minnesota study, illness was associated with tomatoes eaten at a restaurant (OR 6·3, mid-P 95% CI 1·05–50·4, P=0·046). State, local and federal regulatory officials traced the source of tomatoes to Ohio tomato fields, a growing area not previously identified in past tomato-associated outbreaks. Because tomatoes are commonly eaten raw, prevention of tomato contamination should include interventions on the farm, during packing, and at restaurants.
Psychological measures have little sensitivity in the prediction of postnatal depression. We report the development
of a questionnaire of beliefs about pregnancy and motherhood. Information from a literature review, staff working
with women with postnatal depression and interviews with recently ill patients was used to develop a questionnaire
called the PRBQ. The PRBQ was piloted on 42 pregnant women and achieved a Cronbach alpha of 0.85. Scores
significantly correlated with scores on the Dysfunctional Attitude Scale (DAS), Beck Depression Inventory (BDI) and
the Cognitive Adaptation to Stressful Events questionnaire (CASE), measuring adaptation to pregnancy. DAS and
CASE scores did not correlate. The PRBQ and the CASE differentiated between those with (n = 5) and those without
moderate depression. The PRBQ has been validated against established psychological measures. It may be a helpful
tool contributing to the identification of women specifically at risk of postnatal depression. Further basic research is
Emergency medical technicians (EMTs) find that the death of patients in their care is stressful.
Random sample of certified EMTs in one state (Levels I–IV).
A blinded, self-administered survey was sent to a random sample of 2,500 EMTs. Demographic data obtained were: level of training; hours worked each month; population of area served; age; gender; number of deaths per year; training for coping prehospital deaths; and availability of protocols and on-line medical advice for out-of-hospital deaths. A five-point, Likert scale was used to rate the frequency of perceived stress experienced by EMTs in specific situations and the routine practice for notification of survivors. Univariable analysis was performed using Spearman's Rank correlation, Kruskal-Wallis test, and Mann-Whitney U-test. Multivariable correlations were performed using forward and backward step-wise logistic regression analysis. A significance level of 0.05 was used throughout.
There were 654 respondents with a mean age of 35.5±8.3 yr; 83% were men. Their highest level of training was: 4% EMT-I, 43% EMT-II, 18% EMT-III, 33% EMT-IV. They saw an average of 9.6 deaths/year and spent an average of 20±17 minutes with survivors. 62 % found treatment of a patient that was dying or died in their care was commonly a stressful experience. Factors that made notification of the family about the prehospital death emotionally difficult included: fewer hours worked/month; working in a smaller community; lower level of EMT training; female gender; and fewer deaths seen during the previous year. The same factors were associated with general emotional difficulty in treatment of a patient who died during prehospital care. Online [direct] medical direction by physicians was common (73%), but did not lessen the difficulty of notification. It did reduce the emotional difficulty for specific clinical situations. Written protocols for not attempting resuscitation were common (66%), but only 44% had protocols for termination of resuscitation. Resuscitation of the clearly dead for the benefit of the family (10%) or for the EMT (5%) was practiced infrequently. Most (67%) respondents had some formal training in dealing with death and the dying patient. Such training did not correlate with less difficulty in notification of survivors or in coping with the deaths of patients in their care.
EMTs perceive they have emotional difficulty when prehospital deaths occur and survivors must be notified. Less experience and a lower level of EMT training correlate with more difficulty in coping with patient death. Protocols and on-line [direct] medical control can provide support for the EMT in coping with out-of-hospital deaths. Most notification of survivors is handled by EMTs with formal training to cope with patients that are dying or who die during prehospital care.
Problems of analyzing by TEM and TPD (Temperature Programmed Desorption) the structure and micromorphology of small Pd particles vapor deposited in UHV onto clean oxide supports are discussed. Particle changes induced during extended exposures to high intensity electron irradiation of a number of electron transparent support materials such as Al2O3, SiO2, TiO2, MgO, and mica are examined. Different damage mechanisms are evaluated and experimental means of reducing the damage are explored. The possibility of extracting particle morphology information from a detailed analysis of CO thermal desorption spectra is also investigated. Evidence suggests that it may be possible to obtain micromorphology information down to very small particle sizes from TPD measurements if the effects of intrinsic particle morphology can be separated from the influence of diffusion of support species.
Email your librarian or administrator to recommend adding this to your organisation's collection.