605 research outputs found

    Holocene Precipitation Variability, Prehistoric Agriculture, and Natural and Human-Set Fires in Costa Rica

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    This dissertation presents the results of compound-specific stable hydrogen isotope analysis of n-alkanes from terrestrial leaf waxes preserved in sediment cores from three lakes in Costa Rica to reconstruct variations in paleohydrology during the Holocene. Results were compared with pollen and charcoal data from the same cores to examine relationships between paleohydrology, vegetation change, prehistoric agriculture, and fire, and with archaeological evidence in the watersheds of two lakes to better understand prehistoric human-environment interactions. Lago de las Morrenas 1 (9.4925 °N, 83.4848 °W, 3480 m) is in the Chirripó páramo of Costa Rica, which was never permanently occupied by prehistoric people. The analyses demonstrate 10,000 years of millennial-scale variations in hydroclimate at Morrenas 1, which was dry during the Early Holocene, mesic during the Middle Holocene, and dry over the Late Holocene. The Morrenas sediments record local manifestations of the 8200 BP event, the 5200 BP event, the Terminal Classic Drought (TCD), and the Little Ice Age (LIA). Laguna Bonillita (9.9921 °N, 83.6114 °W, 450 m), in the Caribbean lowlands of central Costa Rica, has a 2700-year history of continuous maize agriculture. The alkane data show variations in paleohydrology over the Late Holocene and local manifestations of the TCD and the LIA that match patterns throughout the circum-Caribbean. The Bonillita watershed was intensively farmed across the entire history of the lake. Changes in prehistoric culture and maize farming are temporally linked to climate change at Bonillita. The data indicate that maize agriculture benefitted from episodes of drier climate in this lowland rainforest environment. Laguna Santa Elena (8.9290 °N, 82.9257 °W, 1055 m), in the Diquís archaeological subregion of southern Pacific Costa Rica, has a 2000-year history of maize agriculture. The analyses document variations in Late Holocene paleohydrology, including local manifestations of the TCD and the LIA, that had important consequences for prehistoric people. Santa Elena may have experienced a decrease in rainfall during the TCD, but unlike the Caribbean side of the Isthmus, the amplitude of this drought event does not appear abnormal on centennial to millennial timescales. Two population collapses inferred to take place during dry periods instead happened during wet intervals at Santa Elena

    Stable Isotope Analysis of Lake Sediments from Laguna Santa Elena and Laguna Azul, Costa Rica

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    Lake sediments are increasingly important archives of human-environment interactions and paleoclimate in the neotropics. In Costa Rica, Anchukaitis and Horn (Palaeogeography, Palaeoclimatology, Palaeoecology 221: 35–54, 2005) established a land-use history for Laguna Santa Elena (8.9306 N, 82.9275 W, 1055 m elevation), a small lake in the Diquís archaeological region, based on pollen and charcoal analyses of a 7-meter sediment core. I carried out stable carbon and nitrogen isotope and loss-on-ignition analyses at higher resolution to extend the existing 2000-year record. The new geochemical data parallel major trends in botanical proxies but also reveal aspects of human and environmental dynamics not apparent in the prior analysis. Inferred changes in land use in the watershed are consistent with archaeological evidence. Geochemical trends strongly suggest a population collapse at the site around the time of the Terminal Classic Drought of the Mayan region. The generally close correspondence between microfossil assemblages and geochemistry in the Santa Elena core demonstrates the usefulness of stable isotope analysis as a first line of investigation in paleoenvironmental research. Sediment samples for carbon isotope analysis need to be acidified to remove carbonates that can affect isotope measurements, and debate exists over whether nitrogen isotope analysis can use these acidified samples or require non-acidified samples. My thesis research tested the effects of pre-analysis acidification of sediment and soil samples from Laguna Santa Elena and a second lake in Costa Rica, Laguna Azul (9.9558 N, 83.6519 W, 630 m elevation) in the Central Highlands-Atlantic Watershed archaeological region. Results show that acidification may cause statistically significant differences in nitrogen isotope values. These differences appear to be random and unpredictable, and can manifest as either positive or negative shifts that have the potential to alter or even reverse relative trends in nitrogen isotope signals in lake sediment profiles. More tests are needed, but the results of this analysis suggest that researchers should avoid dual-mode analysis, in which data for both stable carbon and nitrogen isotopes are obtained from a single acidified sample, and should continue analyzing an additional non-acidified sample to obtain nitrogen isotope values

    Perspectives on the application of technology to enhance learning in an undergraduate nursing degree programme

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    This paper discusses concepts and practice relating to the use of computer-based technologies for enhancing learning. It draws on examples from a UK nursing degree programme

    Guide to Geographical Indications: Linking Products and Their Origins (Summary)

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    Geographical Indications present significant opportunities for differentiating products or services that are uniquely related to their geographic origin. While they can offer many positive economic, social, cultural, and even environmental benefits, they can also be problematic and therefore caution is warranted when pursuing them. The publication distills the relevant lessons that could apply, particularly to developing countries, from a review of more than 200 documents and a number of original Case Studies. It presents a groundwork to better understand the costs and the benefits of undertaking Geographical Indications by outlining the basic processes, covering the pros and cons of different legal instruments, and offering insights into the important factors of success. It reviews and presents current data on the key issues of global GIs such as: economic results, public and private benefits; and market relevance.Geographical Indications, developing country, marketing, local, traditional, culture, appellation, legal protection, Denomination of Origin

    Physician assessments of medication adherence and decisions to intensify medications for patients with uncontrolled blood pressure: still no better than a coin toss

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    Abstract Background Many patients have uncontrolled blood pressure (BP) because they are not taking medications as prescribed. Providers may have difficulty accurately assessing adherence. Providers need to assess medication adherence to decide whether to address uncontrolled BP by improving adherence to the current prescribed regimen or by intensifying the BP treatment regimen by increasing doses or adding more medications. Methods We examined how provider assessments of adherence with antihypertensive medications compared with refill records, and how providers’ assessments were associated with decisions to intensify medications for uncontrolled BP. We studied a cross-sectional cohort of 1169 veterans with diabetes presenting with BP ≥140/90 to 92 primary care providers at 9 Veterans Affairs (VA) facilities from February 2005 to March 2006. Using VA pharmacy records, we utilized a continuous multiple-interval measure of medication gaps (CMG) to assess the proportion of time in prior year that patient did not possess the prescribed medications; CMG ≥20% is considered clinically significant non-adherence. Providers answered post-visit Likert-scale questions regarding their assessment of patient adherence to BP medications. The BP regimen was considered intensified if medication was added or increased without stopping or decreasing another medication. Results 1064 patients were receiving antihypertensive medication regularly from the VA; the mean CMG was 11.3%. Adherence assessments by providers correlated poorly with refill history. 211 (20%) patients did not have BP medication available for ≥ 20% of days; providers characterized 79 (37%) of these 211 patients as having significant non-adherence, and intensified medications for 97 (46%). Providers intensified BP medications for 451 (42%) patients, similarly whether assessed by provider as having significant non-adherence (44%) or not (43%). Conclusions Providers recognized non-adherence for less than half of patients whose pharmacy records indicated significant refill gaps, and often intensified BP medications even when suspected serious non-adherence. Making an objective measure of adherence such as the CMG available during visits may help providers recognize non-adherence to inform prescribing decisions.http://deepblue.lib.umich.edu/bitstream/2027.42/112850/1/12913_2012_Article_2450.pd

    Repetitive Transcranial Magnetic Stimulation (rTMS) for depression : outcomes in a United Kingdom (UK) clinical practice

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    Objective: The aim of this paper is to present the outcomes data from the largest United Kingdom’s (UK) National Health Service (NHS) clinical rTMS service treating treatment resistant depression (TRD). Methods: The study was a retrospective investigation of routinely collected data on patients receiving rTMS between 2015 and 2017. Measures used were the clinician-rated Clinical Global Impression (CGI) and Hamilton Depression Rating Scale (HAM-D), and patient rated Beck Depression Inventory (BDI). The outcome data of 73 patients with TRD was analysed. The sample included patients with co-morbid psychiatric diagnosis. Results: Response and remission rates respectively were 40.4% and 25.5% for the HAM-D; 35.6% and 20.8% for the BDI; and 51.1% and 52.1% for the CGI. Effect sizes were medium (.54, .52 and .56 respectively). Conclusions: The results show that a UK based clinical service achieves similar results to those published internationally and that clinical rTMS can have significant impact on symptoms of depression in many patients with TRD. Health services are under pressure to make financial savings, investment in rTMS could reduce the long term treatment costs associated with TRD

    Study protocol: The Adherence and Intensification of Medications (AIM) study - a cluster randomized controlled effectiveness study

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    Abstract Background Many patients with diabetes have poor blood pressure (BP) control. Pharmacological therapy is the cornerstone of effective BP treatment, yet there are high rates both of poor medication adherence and failure to intensify medications. Successful medication management requires an effective partnership between providers who initiate and increase doses of effective medications and patients who adhere to the regimen. Methods In this cluster-randomized controlled effectiveness study, primary care teams within sites were randomized to a program led by a clinical pharmacist trained in motivational interviewing-based behavioral counseling approaches and authorized to make BP medication changes or to usual care. This study involved the collection of data during a 14-month intervention period in three Department of Veterans Affairs facilities and two Kaiser Permanente Northern California facilities. The clinical pharmacist was supported by clinical information systems that enabled proactive identification of, and outreach to, eligible patients identified on the basis of poor BP control and either medication refill gaps or lack of recent medication intensification. The primary outcome is the relative change in systolic blood pressure (SBP) measurements over time. Secondary outcomes are changes in Hemoglobin A1c, low-density lipoprotein cholesterol (LDL), medication adherence determined from pharmacy refill data, and medication intensification rates. Discussion Integration of the three intervention elements - proactive identification, adherence counseling and medication intensification - is essential to achieve optimal levels of control for high-risk patients. Testing the effectiveness of this intervention at the team level allows us to study the program as it would typically be implemented within a clinic setting, including how it integrates with other elements of care. Trial Registration The ClinicalTrials.gov registration number is NCT00495794.http://deepblue.lib.umich.edu/bitstream/2027.42/78258/1/1745-6215-11-95.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78258/2/1745-6215-11-95.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/78258/3/1745-6215-11-95-S1.DOCPeer Reviewe

    Iridium-catalysed ortho-directed deuterium labelling of aromatic esters – an experimental and theoretical study on directing group chemoselectivity

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    Herein we report a combined experimental and theoretical study on the deuterium labelling of benzoate ester derivatives, utilizing our developed iridium N-heterocyclic carbene/phosphine catalysts. A range of benzoate esters were screened, including derivatives with electron-donating and -withdrawing groups in the para- position. The substrate scope, in terms of the alkoxy group, was studied and the nature of the catalyst counter-ion was shown to have a profound effect on the efficiency of isotope exchange. Finally, the observed chemoselectivity was rationalized by rate studies and theoretical calculations, and this insight was applied to the selective labelling of benzoate esters bearing a second directing group

    Outcome Measures for Interventions to Reduce Inappropriate Chronic Drugs: A Narrative Review

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163374/3/jgs16697-sup-0001-Supinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163374/2/jgs16697_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163374/1/jgs16697.pd
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