685 research outputs found
The Soybean Aphid: Perspectives from Across the Street
On June 18, 2001, one of us (B.L.) found soybean aphids, Aphis glycines, on VI-stage soybean plants near Decorah in northeastern Iowa. Aphids were common in river-bottom fields and the highest density was 20 aphids per plant. Most of the aphids were clustered on the youngest unexpanded trifoliate leaf. Aphids were not found on hilltop fields even though there were woodlands nearby that might harbor their alternate host, buckthorn. Thus began the second year of our experience with the soybean aphid. This paper will give a brief overview of our understanding of the soybean aphid, potential management guidelines, and insecticide performance data from neighboring states
Imaging through turbulence with a quadrature-phase optical interferometer
We present an improved technique for imaging through turbulence at visible wavelengths using a rotation shearing pupil-plane interferometer, intended for astronomical and terrestrial imaging applications. While previous astronomical rotation shearing interferometers have made only visibility modulus measurements, this interferometer makes four simultaneous measurements on each interferometric baseline, with phase differences of Ï/2 between each measurement, allowing complex visibility measurements (modulus and phase) across the entire input pupil in a single exposure. This technique offers excellent wavefront resolution, allowing operation at visible wavelengths on large apertures, is potentially immune to amplitude fluctuations (scintillation), and may offer superior calibration capabilities to other imaging techniques. The interferometer has been tested in the laboratory under weakly aberrating conditions and at Palomar Observatory under ordinary astronomical observing conditions. This research is based partly on observations obtained at the Hale Telescope
Operationalizing resilience for conservation objectives: the 4Sâs
Although resilience thinking is increasingly popular and attractive among restoration practitioners, it carries an abstract quality that hinders effective application. Because resilience and its components are defined differently in social and ecological contexts, individual managers or stakeholders may disagree on the definition of a systemâs state, occurrence of a state change, preferred state characteristics, and appropriate methods to achieve success. Nevertheless, incentives and mandates often force managers to demonstrate how their work enhances resilience. Unclear or conflicting definitions can lead to ineffective or even detrimental decision-making in the name of resilience; essentially, any convenient action can be touted as resilience-enhancing in this case. We contend that any successful resilience management project must clearly identify up-front the stressors of concern, state traits, scales of appropriate management, and success indicators (the 4Sâs) relevant to the management targets. We propose a deliberate process for determining these components in advance of resilience management for conservation. Our recommendations were inspired and informed by two case studies wherein different definitions of stressors, state, scales, and success would result in very different management choices, with potentially serious consequences for biodiversity targets
The conservation ecology of North American pleurocerid and hydrobiid gastropods
Many North American freshwater mollusks are at risk of extinction. Knowledge of basic ecology and systematics of the pleurocerid and hydrobiid gastropods is lacking. Pleurocerids are most diverse in southeastern USA, and we know that periphyton food limits their growth, and that their grazing, in turn, limits periphyton biomass. However, we know little about the effects of spates and current velocity on pleurocerid populations, and more work is needed to determine whether interspecific competition or significant risk from predation occurs. Hydrobiids are extremely diverse, but many species inhabit only a few springs (especially in arid western USA) and are at risk of extinction. More work is needed on their population and community ecology. Invasions pose a risk to native snail species. For example, the New Zealand mudsnail (Potamopyrgus antipodarum) interacts negatively with several hydrobiids in the Snake River in western USA. We suggest several research avenues that are needed if we are to maintain and restore pleurocerid and hydrobiid snail populations. © 2008 by The North American Benthological Society
Cardiometabolic effects of a novel SIRT1 activator, SRT2104, in people with type 2 diabetes mellitus
Background: The cardiometabolic effects of SRT2104,
a novel SIRT1 activator, were investigated in people with
type 2 diabetes mellitus (T2DM).
Methods: Fifteen adults with T2DM underwent a
randomised, double-blind, placebo-controlled cross-over
trial and received 28 days of oral SRT2104 (2.0 g/day)
or placebo. Forearm vasodilatation (measured during
intrabrachial bradykinin, acetylcholine and sodium
nitroprusside infusions) as well as markers of glycaemic
control, lipid profile, plasma fibrinolytic factors, and
markers of platelet-monocyte activation, were measured
at baseline and at the end of each treatment period.
Results: Lipid profile and platelet-monocyte
activation were similar in both treatment arms
(p>0.05 for all). Forearm vasodilatation was
similar on exposure to acetylcholine and sodium
nitroprusside (p>0.05,respectively). Bradykinin-induced
vasodilatation was less during treatment with SRT2104
versus placebo (7.753vs9.044, respectively, mean
difference=â1.291,(95% CI â2.296 to â0.285, p=0.012)).
Estimated net plasminogen activator inhibitor type 1
antigen release was reduced in the SRT2104 arm versus
placebo (mean difference=â38.89 ng/100mL tissue/
min, (95%CI â75.47, to â2.305, p=0.038)). There were
no differences in other plasma fibrinolytic factors (p>0.05
for all). After 28 days, SRT2104 exposure was associated
with weight reduction (â0.93 kg (95% CI â1.72 to â0.15),
p=0.0236), and a rise in glycated haemoglobin (5 mmol/
mol or 0.48% (0.26 to 0.70), p=0.004)
Conclusions: In people with T2DM, SRT2104 had
inconsistent, predominantly neutral effects on endothelial
and fibrinolytic function, and no discernible effect on lipids
or platelet function. In contrast, weight loss was induced
along with deterioration in glycaemic control, suggestive of
potentially important metabolic effects.
Clinical trial registration: NCT01031108; Results
Effect of hypoglycaemia on measures of myocardial blood flow and myocardial injury in adults with and without type 1 diabetes:A prospective, randomised, open-label, blinded endpoint, cross-over study
Abstract Aims This study examined the effect of experimentallyâinduced hypoglycaemia on measures of myocardial blood flow and myocardial injury in adults with, and without, type 1 diabetes. Methods In a prospective, randomised, openâlabel, blinded, endpoint crossâover study, 17 young adults with type 1 diabetes with no cardiovascular risk factors, and 10 healthy nonâdiabetic volunteers, underwent hyperinsulinaemicâeuglycaemic (blood glucose 4.5â5.5 mmol/L) and hypoglycaemic (2.2â2.5 mmol/L) clamps. Myocardial blood flow was assessed using transthoracic echocardiography Doppler coronary flow reserve (CFR) and myocardial injury using plasma highâsensitivity cardiac troponin I (hsâcTnI) concentration. Results During hypoglycaemia, coronary flow reserve trended nonâsignificantly lower in those with type 1 diabetes than in the nonâdiabetic participants (3.54 ± 0.47 vs. 3.89 ± 0.89). A generalised linear mixedâmodel analysis examined diabetes status and euglycaemia or hypoglycaemia as factors affecting CFR. No statistically significant difference in CFR was observed for diabetes status (p = .23) or between euglycaemia and hypoglycaemia (p = .31). No changes in hsâcTnI occurred during hypoglycaemia or in the recovery period (p = .86). Conclusions A small change in CFR was not statistically significant in this study, implying hypoglycaemia may require more than coronary vasomotor dysfunction to cause harm. Further larger studies are required to investigate this putative problem
Patient active time during therapy sessions in postacute rehabilitation: Development and validation of a new measure
BACKGROUND AND PURPOSE: The accurate measurement of therapy intensity in postacute rehabilitation is important for research to improve outcomes in this setting. We developed and validated a measure of Patient Active Time during physical (PT) and occupational therapy (OT) sessions, as a proxy for therapy intensity. METHODS: This measurement validity study was carried out with 26 older adults admitted to a skilled nursing facility (SNF) for postacute rehabilitation with a variety of main underlying diagnoses, including hip fracture, cardiovascular diseases, stroke, and others. They were participants in a randomized controlled trial that compared an experimental high-intensity therapy to standard-of-care therapy. Patient Active Time was observed by research raters as the total number of minutes that a patient was actively engaging in therapeutic activities during PT and OT sessions. This was compared to patient movement (actigraphy) quantified during some of the same PT/OT sessions using data from three-dimensional accelerometers worn on the patientâs extremities. RESULTS: Activity measures were collected for 136 therapy sessions. Patient Active Time had high interrater reliability in both PT (r = 0.995, p < 0.001) and OT (r = 0.95, p = 0.012). Active time was significantly correlated with actigraphy in both PT (r = 0.73, p < 0.001) and OT (r = 0.60, p < 0.001) and discriminated between a high-intensity experimental condition and standard of care rehabilitation: in PT, 47.0 ± 13.5 min versus 16.7 ± 10.1 min (p < 0.001) and in OT, 46.2 ± 15.2 versus 27.7 ± 6.6 min (p < 0.001). CONCLUSIONS: Systematic observation of Patient Active Time provides an objective, reliable, and valid index of physical activity during PT and OT treatment sessions that has utility as a real-world alternative to the measurement of treatment intensity. This measure could be used to differentiate higher from lower therapy treatment intensity and to help determine the optimal level of active therapy time for patients in postacute and other settings
Upregulation of Phagocyte-Derived Catecholamines Augments the Acute Inflammatory Response
Following our recent report that phagocytic cells (neutrophils, PMNs, and macrophages) are newly discovered sources of catecholamines, we now show that both epinephrine and norepinephrine directly activate NFÎșB in macrophages, causing enhanced release of proinflammatory cytokines (TNFα, IL-1ÎČ, IL-6). Both adrenal-intact (AD+) and adrenalectomized (ADX) rodents were used, because ADX animals had greatly enhanced catecholamine release from phagocytes, facilitating our efforts to understand the role of catecholamines released from phagocytes. Phagocytes isolated from adrenalectomized rats displayed enhanced expression of tyrosine-hydroxylase and dopamine-ÎČ-hydroxylase, two key enzymes for catecholamine production and exhibited higher baseline secretion of norepinephrine and epinephrine. The effects of upregulation of phagocyte-derived catecholamines were investigated in two models of acute lung injury (ALI). Increased levels of phagocyte-derived catecholamines were associated with intensification of the acute inflammatory response, as assessed by increased plasma leak of albumin, enhanced myeloperoxidase content in lungs, augmented levels of proinflammatory mediators in bronchoalveolar lavage fluids, and elevated expression of pulmonary ICAM-1 and VCAM-1. In adrenalectomized rats, development of ALI was enhanced and related to α2-adrenoceptors engagement but not to involvement of mineralocorticoid or glucocorticoid receptors. Collectively, these data demonstrate that catecholamines are potent inflammatory activators of macrophages, upregulating NFÎșB and further downstream cytokine production of these cells. In adrenalectomized animals, which have been used to further assess the role of catecholamines, there appears to be a compensatory increase in catecholamine generating enzymes and catecholamines in macrophages, resulting in amplification of the acute inflammatory response via engagement of α2-adrenoceptors
Functions of the complement components C3 and C5 during sepsis
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154678/1/fsb2fj08110595.pd
Implementing Risk Management Decisions that Optimize Nutrient Value of Dairy Manure while Minimizing Related Risk
Nutrients present in manure are increasingly receiving attention for environmental, production, and financial reasons. Dairy producers continue to strive for better ways and educational opportunities to improve profits by evaluating fertilizer and value of manure to their operation and to protect the environment. These farming decisions which help producers stay economically viable also support and stimulate their local economy, which promotes a more vital rural community. Utilizing 22 dairy nutrient management surveys, 14 on-farm workshops, 10 small group on-farm assessment workshops, one video, and individual producer visits, producers were able to make informed decisions using tools and knowledge gained to control risks associated with manure nutrients during handling, storage, and application
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