3,073 research outputs found
Functional structure of ant and termite assemblages in old growth forest, logged forest and oil palm plantation in Malaysian Borneo
Forested tropical landscapes around the world are being extensively logged and converted to agriculture, with serious consequences for biodiversity and potentially ecosystem functioning. Here we investigate associations between habitat disturbance and functional diversity of ants and termites—two numerically dominant and functionally important taxa in tropical rain forests that perform key roles in predation, decomposition, nutrient cycling and seed dispersal. We compared ant and termite occurrence and composition within standardised volumes of soil and dead wood in old growth forest, logged forest and oil palm plantation in Sabah, Malaysian Borneo. Termites occurred substantially less frequently in converted habitats than in old growth forest, whereas ant occurrences were highest in logged forest and lowest in old growth forest. All termite feeding groups had low occurrence in disturbed habitats, with soil feeders occurring even less frequently than wood feeders. Ant functional groups showed more variable associations, with some opportunist and behaviourally dominant groups being more abundant in degraded habitats. The importance of ants and termites in tropical ecosystems and such differing patterns of assemblage variation suggest that ecosystem functioning may be significantly altered in converted habitats.During this project SHL was funded by the Sime Darby Foundation (through SAFE), the UK Natural Environment Research Council (NERC), The University of East Anglia and The Sir Philip Reckitt Educational Trust. TMF was funded by a NERC small project grant (NE/H011307/1), the project Biodiversity of Forest Ecosystems CZ.1.07/2.3.00/20.0064 co-financed by the European Social Fund and the state budget of the Czech Republic, an Australian Research Council Discovery Grant (DP140101541), and a Czech Science Foundation standard grant (14-32302S).This is the author accepted manuscript. The final version has been published by Springer in Biodiversity and Conservation. It can be found here: http://link.springer.com/article/10.1007%2Fs10531-014-0750-2
A cohort study on mental disorders, stage of cancer at diagnosis and subsequent survival.
OBJECTIVES: To assess the stage at cancer diagnosis and survival after cancer diagnosis among people served by secondary mental health services, compared with other local people. SETTING: Using the anonymised linkage between a regional monopoly secondary mental health service provider in southeast London of four London boroughs, Croydon, Lambeth, Lewisham and Southwark, and a population-based cancer register, a historical cohort study was constructed. PARTICIPANTS: A total of 28 477 cancer cases aged 15+ years with stage of cancer recorded at diagnosis were identified. Among these, 2206 participants had been previously assessed or treated in secondary mental healthcare before their cancer diagnosis and 125 for severe mental illness (schizophrenia, schizoaffective or bipolar disorders). PRIMARY AND SECONDARY OUTCOME MEASURES: Stage when cancer was diagnosed and all-cause mortality after cancer diagnosis among cancer cases registered in the geographical area of southeast London. RESULTS: Comparisons between people with and without specific psychiatric diagnosis in the same residence area for risks of advanced stage of cancer at diagnosis and general survival after cancer diagnosed were analysed using logistic and Cox models. No associations were found between specific mental disorder diagnoses and beyond local spread of cancer at presentation. However, people with severe mental disorders, depression, dementia and substance use disorders had significantly worse survival after cancer diagnosis, independent of cancer stage at diagnosis and other potential confounders. CONCLUSIONS: Previous findings of associations between mental disorders and cancer mortality are more likely to be accounted for by differences in survival after cancer diagnosis rather than by delayed diagnosis
Techno-economic packaging of palm wine preservation and bottling technology for entrepreneurs
The study was carried out to investigate the economic viability of setting up a small scale palm wine bottling factory with a view to providing investment data to guide entrepreneurs in making investment decisions. The economic evaluation was based on a factory capacity of 750,000 bottles (60cl) per annum with production commencing in year one at 75% capacity utilization. Production cost estimate varies between N37.85/bottle (60cl) in the first year and N35.37/bottle (60cl) in the fifth year. The annual netprofits are N8, 460,430.00 and N12, 025,710.00 in years one and five respectively. Projected cash flow is positive in year one i.e. N5,329,960.00 while the projected balance sheet shows that the net worth of theproject is N19,904,010.00 in year one and N41,887,370.00 in year five. Payback period, discounted payback period and profitability index are 1.4 years, 3.3 years and 1.5 respectively. The breakeven point in year one is 48.1% or a breakeven sales volume of N16, 236,312.35.00.  The Return on Investment (ROI) and Return on Equity (ROE) in year one are 57.5% and 86.1% respectively. Capital Turnover Ratio (CTR) varies between 2.3 and 2.9 within the first five years. Internal Rate of Return (IRR) is above 45%. The Net Present Value (NPV) at 25% is estimated at N3, 143,100.00. The Debt Service Coverage Ratio (DSCR) increases gradually from 1.33 to 2.75 between the first and the fifth year
A practical laboratory method to determine ceftazidime-avibactam-aztreonam synergy in patients with New Delhi Metallo-beta-lactamase (NDM) producing Enterobacterales infection
Background: In response to infection with New Delhi Metallo-beta-lactamase (NDM) producing Enterobacterales, combination antimicrobial therapy with ceftazidime/avibactam (CAZ/AVI) plus aztreonam (ATM) has been explored. This study evaluated a practical laboratory method of testing for clinically significant synergy between CAZ/AVI+ATM in NDM producing Enterobacterales. Methods: Minimum inhibitory concentration (MIC) of clinical NDM producing isolates were determined for ATM alone and CAZ/AVI+ATM using broth dilution. Restoration of ATM breakpoint following the addition of CAZ/AVI was explored. A CAZ/AVI E-test/ATM disc method was compared to broth dilution. Results: Of 43 isolates, 33/43 (77%) isolates were ATM resistant (median [range] MIC=56 [16 – 512] mg/L). Addition of CAZ/AVI restored the ATM breakpoint (MIC <4mg/L) in 29/33 (89%) of resistant isolates. Overall, the E-test/disc method correlated with findings from broth dilution in 35/43 (81%) of cases. E-test/disc sensitivity was 77% and specificity 85%. Positive predictive value was 92% and negative predictive value 61%. Conclusion: CAZ/AVI+ATM demonstrated significant synergy in most ATM resistant NDM producing Enterobacterales. The E-test/disc method is a quick, reproducible, and reliable method of testing for clinically relevant synergy in the microbiology laboratory
Resample-smoothing of Voronoi intensity estimators
Voronoi estimators are non-parametric and adaptive estimators of the intensity of a point process. The intensity estimate at a given location is equal to the reciprocal of the size of the Voronoi/Dirichlet cell containing that location. Their major drawback is that they tend to paradoxically under-smooth the data in regions where the point density of the observed point pattern is high, and over-smooth where the point density is low. To remedy this behaviour, we propose to apply an additional smoothing operation to the Voronoi estimator, based on resampling the point pattern by independent random thinning. Through a simulation study we show that our resample-smoothing technique improves the estimation substantially. In addition, we study statistical properties such as unbiasedness and variance, and propose a rule-of-thumb and a data-driven cross-validation approach to choose the amount of smoothing to apply. Finally we apply our proposed intensity estimation scheme to two datasets: locations of pine saplings (planar point pattern) and motor vehicle traffic accidents (linear network point pattern)
Efficacy of Thermotherapy to Treat Cutaneous Leishmaniasis Caused by Leishmania tropica in Kabul, Afghanistan: A Randomized, Controlled Trial
BACKGROUND: Pentavalent antimony is the agent recommended for treatment of cutaneous leishmaniasis (CL). Its use is problematic, because it is expensive and because of the potential for drug-associated adverse effects during a lengthy and painful treatment course.
METHODS: We tested the efficacy of thermotherapy for the treatment of CL due to Leishmania tropica in a randomized, controlled trial in Kabul, Afghanistan. We enrolled 401 patients with a single CL lesion and administered thermotherapy using radio-frequency waves (1 treatment of ≥1 consecutive application at 50°C for 30 s) or sodium stibogluconate (SSG), administered either intralesionally (a total of 5 injections of 25 mL every 57 days, depending on lesion size) or intramuscularly (20 mg/kg daily for 21 days).
RESULTS: Cure, defined as complete reepithelialization at 100 days after treatment initiation, was observed in 75 (69.4%) of 108 patients who received thermotherapy, 70 (75.3%) of 93 patients who received intralesional SSG, and 26 (44.8%) of 58 patients who received intramuscular SSG. The OR for cure with thermotherapy was 2.80 (95% confidence interval [CI], 1.455.41), compared with intramuscular SSG treatment (P = .002). No statistically significant difference was observed in the odds of cure in comparison of intralesional SSG and thermotherapy treatments. The OR for cure with intralesional SSG treatment was 3.75 (95% CI, 1.867.54), compared with intramuscular SSG treatment (P 100 days, respectively; P = .003).
CONCLUSIONS: Thermotherapy is an effective, comparatively well-tolerated, and rapid treatment for CL, and it should be considered as an alternative to antimony treatment
A transcriptomic snapshot of early molecular communication between Pasteuria penetrans and Meloidogyne incognita
© The Author(s). 2018Background: Southern root-knot nematode Meloidogyne incognita (Kofoid and White, 1919), Chitwood, 1949 is a key pest of agricultural crops. Pasteuria penetrans is a hyperparasitic bacterium capable of suppressing the nematode reproduction, and represents a typical coevolved pathogen-hyperparasite system. Attachment of Pasteuria endospores to the cuticle of second-stage nematode juveniles is the first and pivotal step in the bacterial infection. RNA-Seq was used to understand the early transcriptional response of the root-knot nematode at 8 h post Pasteuria endospore attachment. Results: A total of 52,485 transcripts were assembled from the high quality (HQ) reads, out of which 582 transcripts were found differentially expressed in the Pasteuria endospore encumbered J2 s, of which 229 were up-regulated and 353 were down-regulated. Pasteuria infection caused a suppression of the protein synthesis machinery of the nematode. Several of the differentially expressed transcripts were putatively involved in nematode innate immunity, signaling, stress responses, endospore attachment process and post-attachment behavioral modification of the juveniles. The expression profiles of fifteen selected transcripts were validated to be true by the qRT PCR. RNAi based silencing of transcripts coding for fructose bisphosphate aldolase and glucosyl transferase caused a reduction in endospore attachment as compared to the controls, whereas, silencing of aspartic protease and ubiquitin coding transcripts resulted in higher incidence of endospore attachment on the nematode cuticle. Conclusions: Here we provide evidence of an early transcriptional response by the nematode upon infection by Pasteuria prior to root invasion. We found that adhesion of Pasteuria endospores to the cuticle induced a down-regulated protein response in the nematode. In addition, we show that fructose bisphosphate aldolase, glucosyl transferase, aspartic protease and ubiquitin coding transcripts are involved in modulating the endospore attachment on the nematode cuticle. Our results add new and significant information to the existing knowledge on early molecular interaction between M. incognita and P. penetrans.Peer reviewedFinal Published versio
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Designing theoretically-informed implementation interventions
Clinical and health services research is continually producing new findings that may contribute to effective and efficient patient care. However, the transfer of research findings into practice is unpredictable and can be a slow and haphazard process. Ideally, the choice of implementation strategies would be based upon evidence from randomised controlled trials or systematic reviews of a given implementation strategy. Unfortunately, reviews of implementation strategies consistently report effectiveness some, but not all of the time; possible causes of this variation are seldom reported or measured by the investigators in the original studies. Thus, any attempts to extrapolate from study settings to the real world are hampered by a lack of understanding of the effects of key elements of individuals, interventions, and the settings in which they were trialled. The explicit use of theory offers a way of addressing these issues and has a number of advantages, such as providing: a generalisable framework within which to represent the dimensions that implementation studies address, a process by which to inform the development and delivery of interventions, a guide when evaluating, and a way to allow for an exploration of potential causal mechanisms. However, the use of theory in designing implementation interventions is methodologically challenging for a number of reasons, including choosing between theories and faithfully translating theoretical constructs into interventions. The explicit use of theory offers potential advantages in terms of facilitating a better understanding of the generalisability and replicability of implementation interventions. However, this is a relatively unexplored methodological area
A new method to quantify and compare the multiple components of fitness-A study case with kelp niche partition by divergent microstage adaptations to Temperature
Point 1 Management of crops, commercialized or protected species, plagues or life-cycle evolution are subjects requiring comparisons among different demographic strategies. The simpler methods fail in relating changes in vital rates with changes in population viability whereas more complex methods lack accuracy by neglecting interactions among vital rates. Point 2 The difference between the fitness (evaluated by the population growth rate.) of two alternative demographies is decomposed into the contributions of the differences between the pair-wised vital rates and their interactions. This is achieved through a full Taylor expansion (i.e. remainder = 0) of the demographic model. The significance of each term is determined by permutation tests under the null hypothesis that all demographies come from the same pool. Point 3 An example is given with periodic demographic matrices of the microscopic haploid phase of two kelp cryptic species observed to partition their niche occupation along the Chilean coast. The method provided clear and synthetic results showing conditional differentiation of reproduction is an important driver for their differences in fitness along the latitudinal temperature gradient. But it also demonstrated that interactions among vital rates cannot be neglected as they compose a significant part of the differences between demographies. Point 4 This method allows researchers to access the effects of multiple effective changes in a life-cycle from only two experiments. Evolutionists can determine with confidence the effective causes for changes in fitness whereas population managers can determine best strategies from simpler experimental designs.CONICYT-FRENCH EMBASSADY Ph.D. gran
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