185 research outputs found

    Spatial dynamics of mammals and their pathogens and parasites

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    In this dissertation, I explore several aspects of the ecological dynamics of mammals and their pathogens and parasites. I approach this broad topic at various scales, using Ecological Niche Models, field surveys, and theoretical simulations. I focus on two pathogens, hantavirus and plague (Yersinia pestis), and a group of parasites, fleas, and address their spatial and ecological relationships. Each of the four chapters presents a set of questions and tests hypotheses regarding the distribution of these taxa. I begin by demonstrating that plague-infected host distributions are not similar to the non-infected host distributions, suggesting that vector ecology may drive the distribution of plague in the western United States. I then show that hantavirus prevalence and flea communities are not mediated by mammalian communities across a contiguous landscape, and flea communities differ with increasing elevation. Finally, I show that re-appearance of hantavirus after a decline in host populations likely is not driven by metapopulation dynamics

    Patterns of host and flea communities along an elevational gradient in Colorado

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    Patterns in community composition across a landscape are the result of mechanistic responses and species interactions. Interactions between hosts and parasites have additional complexity because of the contingency of host presence and interactions among parasites. To assess the role of environmental changes within host and parasites communities, we surveyed small mammals and their fleas over a dynamic elevational gradient in the Front Range in Colorado, USA. Communities were characterized using several richness and diversity metrics and these were compared using a suite of frequentist and randomization approaches. We found that flea species richness was related to the number of host species based upon rarefaction, but no patterns in richness with elevation were evident. Values of diversity measures increased with elevation, representing that small-mammal and flea communities were more even upslope, yet turnover in composition was not related to examined variables. The results suggest there are strong local effects that drive these small-mammal and flea communities, although the breadth of flea species is tied to host availability

    Methods for Increasing the Electron Richness of Iron Tricarbonyl Diimine Complexes

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    Francesca Lombardi ’24, Major: Chemistry Joseph Maher ’25, Major: Chemistry Sean Peloquin ’26, Major: Biochemistry Faculty Mentor: Dr. Maria Carroll, Chemistry and Biochemistry The goal of our research is to synthesize new iron complexes that can reduce carbon dioxide. Increasing the electron richness of iron tricarbonyl diimine complexes, which have been synthesized previously in the Carroll research group, will increase the likelihood of a reaction with carbon dioxide occurring. We have taken two approaches to changing the electron density in the complexes. First, we reacted the complex Fe((CF3)2ArDABMe)(CO)¬3 with the reducing agent potassium on graphite, in order to reduce either the iron center or the diimine ligand. Second, we synthesized the new iron complex, Fe(CyDABMe)(CO)¬3, which has a more electron donating ligand than those previously synthesized

    Beyond a warming fingerprint: individualistic biogeographic responses to heterogeneous climate change in California.

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    Understanding recent biogeographic responses to climate change is fundamental for improving our predictions of likely future responses and guiding conservation planning at both local and global scales. Studies of observed biogeographic responses to 20th century climate change have principally examined effects related to ubiquitous increases in temperature - collectively termed a warming fingerprint. Although the importance of changes in other aspects of climate - particularly precipitation and water availability - is widely acknowledged from a theoretical standpoint and supported by paleontological evidence, we lack a practical understanding of how these changes interact with temperature to drive biogeographic responses. Further complicating matters, differences in life history and ecological attributes may lead species to respond differently to the same changes in climate. Here, we examine whether recent biogeographic patterns across California are consistent with a warming fingerprint. We describe how various components of climate have changed regionally in California during the 20th century and review empirical evidence of biogeographic responses to these changes, particularly elevational range shifts. Many responses to climate change do not appear to be consistent with a warming fingerprint, with downslope shifts in elevation being as common as upslope shifts across a number of taxa and many demographic and community responses being inconsistent with upslope shifts. We identify a number of potential direct and indirect mechanisms for these responses, including the influence of aspects of climate change other than temperature (e.g., the shifting seasonal balance of energy and water availability), differences in each taxon's sensitivity to climate change, trophic interactions, and land-use change. Finally, we highlight the need to move beyond a warming fingerprint in studies of biogeographic responses by considering a more multifaceted view of climate, emphasizing local-scale effects, and including a priori knowledge of relevant natural history for the taxa and regions under study

    Improving Completeness and Transparency of Reporting in Clinical Trials Using the Template for Intervention Description and Replication (TIDieR) Checklist Will Benefit the Physiotherapy Profession

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    Incomplete reporting of interventions in physiotherapy studies is an important problem and The Journal of Manual and Manipulative Therapy endorses the use of the TIDieR checklist as a potential solution

    Magnetospheric MultiScale (MMS) System Manager

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    The Magnetospheric MultiScale (MMS) mission is an ambitious NASA space science mission in which 4 spacecraft are flown in tight formation about a highly elliptical orbit. Each spacecraft has multiple instruments that measure particle and field compositions in the Earths magnetosphere. By controlling the members relative motion, MMS can distinguish temporal and spatial fluctuations in a way that a single spacecraft cannot.To achieve this control, 2 sets of four maneuvers, distributed evenly across the spacecraft must be performed approximately every 14 days. Performing a single maneuver on an individual spacecraft is usually labor intensive and the complexity becomes clearly increases with four. As a result, the MMS flight dynamics team turned to the System Manager to put the routine or error-prone under machine control freeing the analysts for activities that require human judgment.The System Manager is an expert system that is capable of handling operations activities associated with performing MMS maneuvers. As an expert system, it can work off a known schedule, launching jobs based on a one-time occurrence or on a set reoccurring schedule. It is also able to detect situational changes and use event-driven programming to change schedules, adapt activities, or call for help

    Palliative Approach for Aged Care

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    In Australia, many people ageing in their own homes are becoming increasingly frail and unwell, approaching the end of life. A palliative approach, which adheres to palliative care principles, is often appropriate. These principles provide a framework for proactive and holistic care in which quality of life and of dying is prioritised, as is support for families. A palliative approach can be delivered by the general practitioner working with the community aged care team, in collaboration with family carers. Support from specialist palliative care services is available if necessary. The Guidelines for a Palliative Approach for Aged Care in the Community Setting were published by the Australian Government Department of Health and Ageing to inform practice in this area. There are three resource documents. The main document provides practical evidence based guidelines, good practice points, tools, and links to resources. This document is written for general practitioners, nurses, social workers, therapists, pastoral care workers, and other health professionals and responded to needs identified during national consultation. Evidence based guidelines were underpinned by systematic reviews of the research literature. Good practice points were developed from literature reviews and expert opinion. Two ‘plain English’ booklets were developed in a process involving consumer consultation; one is for older people and their families, the other for care workers. The resources are intended to facilitate home care that acknowledges and plans for the client’s deteriorating functional trajectory and inevitable death. At a time when hospitals and residential aged care facilities are under enormous pressure as the population ages, such a planned approach makes sense for the health system as a whole. The approach also makes sense for older people who wish to die in their own homes. Family needs are recognised and addressed. Unnecessary hospitalisations or residential placements and clinically futile interventions are also minimised

    Pure iterative reconstruction improves image quality in computed tomography of the abdomen and pelvis acquired at substantially reduced radiation doses in patients with active Crohn disease

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    Objective: We assessed diagnostic accuracy and image quality of modified protocol (MP) computed tomography (CT) of the abdomen and pelvis reconstructed using pure iterative reconstruction (IR) in patients with Crohn disease (CD). Methods: Thirty-four consecutive patients with CD were referred with suspected extramural complications. Two contemporaneous CT datasets were acquired in all patients: standard protocol (SP) and MP. The MP and SP protocols were designed to impart radiation exposures of 10% to 20% and 80% to 90% of routine abdominopelvic CT, respectively. The MP images were reconstructed with model-based IR (MBIR) and adaptive statistical IR (ASIR). Results: The MP-CT and SP-CT dose length product were 88 (58) mGy.cm (1.27 [0.87] mSv) and 303 [204] mGy.cm (4.8 [2.99] mSv), respectively (P < 0.001). Median diagnostic acceptability, spatial resolution, and contrast resolution were significantly higher and subjective noise scores were significantly lower on SP-ASIR 40 compared with all MP datasets. There was perfect clinical agreement between MP-MBIR and SP-ASIR 40 images for detection of extramural complications. Conclusions: Modified protocol CT using pure IR is feasible for assessment of active CD
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