213 research outputs found
Increased area of a highly suitable host crop increases herbivore pressure in intensified agricultural landscapes
Landscape simplification associated with agricultural intensification has important effects on economically important arthropods. The declining cover of natural and semi-natural habitats, in particular, has been shown to reduce natural-enemy attack of crop pests, but also in some cases reduced crop colonization by such pests. In this study, we examined the influence of changes in two elements of landscape composition, natural grassland cover and cover of a highly suitable crop host, on infestation by a generalist insect pest in wheat, and parasitism of this pest by its dominant natural enemies. Surprisingly, we found no significant influences of increasing natural grassland habitat, at either local or landscape scales, on infestation by the wheat stem sawfly, Cephus cinctus, or parasitism of this pest by the native parasitoid wasps, Bracon cephiand Bracon lissogaster. In contrast, we found significant increases in levels of C. cinctus infestation with increasing wheat cover at the landscape scale. This pattern was consistent across six study regions spanning three states in the northern Great Plains of North America, despite large differences in cropping systems and pest population densities across regions. Regional variation in pest infestation was best explained by long-term averages in precipitation, with higher C. cinctus infestation rates found in drier regions. Results suggest that landscape-mediated variation in pest pressure in this system is better explained by a direct response of pest insects to increasing cover of a highly suitable crop rather than an indirect response via reductions in natural enemies as natural habitat declines. The implication is that habitat diversification at the landscape scale could play a role in suppressing agricultural pest populations via reductions in area of suitable crop hosts
Revealing Student Misconceptions and Instructor Blind Spots with Muddiest Point Formative Feedback
Of interest to all engineering disciplines, well-designed formative feedback has the potential to enhance both instructor teaching and student learning. Delivering fundamental courses year after year, can ultimately lead faculty to use stale notes or slides from past years. This approach may save time, but does not meet the shifting needs of our students who have high expectations from their instructors. One simple method to improve teaching is to employ muddiest point reflections. Muddiest point reflections involve simply asking students to anonymously reflect on what was âmuddyâ, i.e. confusing, during class and to rank their level of confusion which not only addresses students falling behind, but also shows students a commitment to their education especially when the instructor puts direct student quotes on the screen. Initially, developing a formative feedback process takes some effort, but once established, using a formative feedback process requires little effort. The formative feedback process includes four steps: 1) acquiring data from student reflections; 2) assessing and characterizing student responses in order to diagnose the learning issues that can impede students from achieving their learning goals; 3) designing and synthesizing the type and mode of formative feedback that best addresses the learning issues; and 4) selecting a formative feedback delivery method that quickly communicates to students the information and/or resources that they can use to enhance progress toward their learning goals.
This paper presents and discusses the nuts and bolts of implementing the feedback process when using end-of-class âMuddiest Pointâ (MP) student reflections. These are collected following a class topic and are collected for the purpose of identifying â and quickly correcting â points of confusion that students individually report (their muddiest point). In addition, we report on several instructor perceptions of their teaching that result from using âmuddiest pointsâ for the first time. These instructors deployed MP in a systematic way in fall, 2015 in several different materials science courses across the country. Finally, we share strategic examples from each instructor, of how using muddiest points in fall, 2015, caught a misconception or point of confusion in their teaching that probably would not have been otherwise known
Evaluation of in vitro and in vivo activity of benzindazole-4,9-quinones against Cryptosporidium parvum
A series of benzindazole-4,9-quinones was tested for growth-inhibitory effects on Cryptosporidium parvum in vitro and in vivo. Most compounds showed considerable activity at concentrations from 25 to 100 ”M. For instance, at 25 ”M the derivatives 5-hydroxy-8-chloro-N 1 -methylbenz[f]-indazole-4,9-quinone and 5-chloro-N 2 -methylbenz[f]indazole-4,9-quinone inhibited growth of C. parvum 78-100%, and at 50 ”M seven of the 23 derivatives inhibited growth â„90%. The activity of the former two compounds was confirmed in a T-cell receptor α (TCR-α)-deficient mouse model of chronic cryptosporidiosis. In these mice, the mean infectivity scores (IS) in the caecum were 0.63-0.20, whereas in sham-treated mice the score was 1.44 (P < 0.05). There were similar differences in IS in the ileum, where the score for treated mice was 1.12-0.20 and that for mice receiving no drug was 1.32. There was no acute or chronic toxicity for any compound tested in vivo
Evolutionary trade-offs associated with loss of PmrB function in host-adapted <i>Pseudomonas aeruginosa</i>
Pseudomonas aeruginosa colonises the upper airway of cystic fibrosis (CF) patients, providing a reservoir of host-adapted genotypes that subsequently establish chronic lung infection. We previously experimentally-evolved P. aeruginosa in a murine model of respiratory tract infection and observed early-acquired mutations in pmrB, encoding the sensor kinase of a two-component system that promoted establishment and persistence of infection. Here, using proteomics, we show downregulation of proteins involved in LPS biosynthesis, antimicrobial resistance and phenazine production in pmrB mutants, and upregulation of proteins involved in adherence, lysozyme resistance and inhibition of the chloride ion channel CFTR, relative to wild-type strain LESB65. Accordingly, pmrB mutants are susceptible to antibiotic treatment but show enhanced adherence to airway epithelial cells, resistance to lysozyme treatment, and downregulate host CFTR expression. We propose that P. aeruginosa pmrB mutations in CF patients are subject to an evolutionary trade-off, leading to enhanced colonisation potential, CFTR inhibition, and resistance to host defences, but also to increased susceptibility to antibiotics.</p
Community-Guided Focus Group Analysis to Examine Cancer Disparities
Accountability for Cancer Care through Undoing Racism and Equity (ACCURE) is a systems-change intervention addressing disparities in treatment initiation and completion and outcomes for early stage Black and White breast and lung cancer patients. Using a community-based participatory research approach, ACCURE is guided by a diverse partnership involving academic researchers, a non-profit community-based organization, its affiliated broader-based community coalition, and providers and staff from two cancer centers
Probing the circumstellar structure of Herbig Ae/Be stars
We present Halpha spectropolarimetry observations of a sample of 23 Herbig
Ae/Be stars. A change in the linear polarisation across Halpha is detected in a
large fraction of the objects, which indicates that the regions around Herbig
stars are flattened (disc-like) on small scales. A second outcome of our study
is that the spectropolarimetric signatures for the Ae stars differ from those
of the Herbig Be stars, with characteristics changing from depolarisation
across Halpha in the Herbig Be stars, to line polarisations in the Ae group.
The frequency of depolarisations detected in the Herbig Be stars (7/12) is
particularly interesting as, by analogy to classical Be stars, it may be the
best evidence to date that the higher mass Herbig stars are surrounded by
flattened structures. For the Herbig Ae stars, 9 out of 11 show a line
polarisation effect that can be understood in terms of a compact Halpha
emission that is itself polarised by a rotating disc-like circumstellar medium.
The spectropolarimetric difference between the Herbig Be and Ae stars may be
the first indication that there is a transition in the Hertzsprung-Russell
Diagram from magnetic accretion at spectral type A to disc accretion at
spectral type B. Alternatively, the interior polarised line emission apparent
in the Ae stars may be masked in the Herbig Be stars due to their higher levels
of Halpha emission.Comment: 14 pages, MNRAS accepte
Cardiometabolic health in people with HIV: expert consensus review
Objectives To develop consensus data statements and clinical recommendations to provide guidance for improving cardiometabolic health outcomes in people with HIV based on the knowledge and experience of an international panel of experts.Methods A targeted literature review including 281 conference presentations, peer-reviewed articles, and background references on cardiometabolic health in adults with HIV published between January 2016 and April 2022 was conducted and used to develop draft consensus data statements. Using a modified Delphi method, an international panel of 16 experts convened in workshops and completed surveys to refine consensus data statements and generate clinical recommendations.Results Overall, 10 data statements, five data gaps and 14 clinical recommendations achieved consensus. In the data statements, the panel describes increased risk of cardiometabolic health concerns in people with HIV compared with the general population, known risk factors, and the potential impact of antiretroviral therapy. The panel also identified data gaps to inform future research in people with HIV. Finally, in the clinical recommendations, the panel emphasizes the need for a holistic approach to comprehensive care that includes regular assessment of cardiometabolic health, access to cardiometabolic health services, counselling on potential changes in weight after initiating or switching antiretroviral therapy and encouraging a healthy lifestyle to lower cardiometabolic health risk.Conclusions On the basis of available data and expert consensus, an international panel developed clinical recommendations to address the increased risk of cardiometabolic disorders in people with HIV to ensure appropriate cardiometabolic health management for this population
Challenges in Australian policy processes for disinvestment from existing, ineffective health care practices
Background Internationally, many health care interventions were diffused prior to the standard use of assessments of safety, effectiveness and cost-effectiveness. Disinvestment from ineffective or inappropriately applied practices is a growing priority for health care systems for reasons of improved quality of care and sustainability of resource allocation. In this paper we examine key challenges for disinvestment from these interventions and explore potential policy-related avenues to advance a disinvestment agenda. Results We examine five key challenges in the area of policy driven disinvestment: 1) lack of resources to support disinvestment policy mechanisms; 2) lack of reliable administrative mechanisms to identify and prioritise technologies and/or practices with uncertain clinical and cost-effectiveness; 3) political, clinical and social challenges to removing an established technology or practice; 4) lack of published studies with evidence demonstrating that existing technologies/practices provide little or no benefit (highlighting complexity of design) and; 5) inadequate resources to support a research agenda to advance disinvestment methods. Partnerships are required to involve government, professional colleges and relevant stakeholder groups to put disinvestment on the agenda. Such partnerships could foster awareness raising, collaboration and improved health outcome data generation and reporting. Dedicated funds and distinct processes could be established within the Medical Services Advisory Committee and Pharmaceutical Benefits Advisory Committee to, a) identify technologies and practices for which there is relative uncertainty that could be the basis for disinvestment analysis, and b) conduct disinvestment assessments of selected item(s) to address existing practices in an analogous manner to the current focus on new and emerging technology. Finally, dedicated funding and cross-disciplinary collaboration is necessary to build health services and policy research capacity, with a focus on advancing disinvestment research methodologies and decision support tools. Conclusion The potential over-utilisation of less than effective clinical practices and the potential under-utilisation of effective clinical practices not only result in less than optimal care but also fragmented, inefficient and unsustainable resource allocation. Systematic policy approaches to disinvestment will improve equity, efficiency, quality and safety of care, as well as sustainability of resource allocation.Adam G Elshaug, Janet E Hiller, Sean R Tunis and John R Mos
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