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Selected AbstractsBehavioural responses to ectoparasites: time-budget adjustments and what matters to Blue Tits Parus caeruleus infested by fleasIBIS, Issue 3 2002Frédéric Tripet Blue Tit nests are often heavily infested by fleas, which feed on the incubating female and the nestlings. Depending on habitat quality, the drawing of blood by fleas reduces offspring quality, or it is compensated by an increase in food provisioning by the adults and may reduce their future reproduction. Given these fitness costs, tits are expected to have evolved behavioural responses enabling them to remove, destroy or minimize the contact with fleas. To identify these traits, we video-recorded the changes in frequency and duration of the hosts' potential anti-flea behavioural defences in nests experimentally infested with low and high flea densities. We also investigated whether flea load affected the number of male feeds delivered to incubating females, and whether the parents increased their rate of food provisioning to the nestlings equally at high flea density. Flea density significantly affected the nest sanitation and sleeping behaviour of Blue Tit females but had no significant effect on grooming. Female Blue Tits increased the frequency but decreased the duration of bouts of these behavioural traits, and hence their time-budgets, based on per hour duration of behaviour, were not significantly affected by flea density. High flea density reduced nestling weight at the early nestling stage but these costs were fully compensated by an increase in female feeding effort. Males did not increase their frequency of food provisioning to incubating females nor to nestlings in heavily infested nests. The results are discussed in the light of parasite-mediated selection on host behaviour and the reciprocal host selection on flea life-history and behavioural traits. [source] A TRIANGULAR MODEL OF DIMENSIONLESS RUNOFF PRODUCING RAINFALL HYETOGRAPHS IN TEXAS,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 4 2003William H. Asquith ABSTRACT: A synthetic triangular hyetograph for a large data base of Texas rainfall and runoff is needed. A hyetograph represents the temporal distribution of rainfall intensity at a point or over a watershed during a storm. Synthetic hyetographs are estimates of the expected time distribution for a design storm and principally are used in small watershed hydraulic structure design. A data base of more than 1,600 observed cumulative hyetographs that produced runoff from 91 small watersheds (generally less than about 50 km2) was used to provide statistical parameters for a simple triangular shaped hyetograph model. The model provides an estimate of the average hyetograph in dimensionless form for storm durations of 0 to 24 hours and 24 to 72 hours. As a result of this study, the authors concluded that the expected dimensionless cumulative hyetographs of 0 to 12 hour and 12 to 24 hour durations were sufficiently similar to be combined with minimal information loss. The analysis also suggests that dimensionless cumulative hyetographs are independent of the frequency level or return period of total storm depth and thus are readily used for many design applications. The two triangular hyetographs presented are intended to enhance small watershed design practice in applicable parts of Texas. [source] Magnesium Sulfate versus Placebo for Paroxysmal Atrial Fibrillation: A Randomized Clinical TrialACADEMIC EMERGENCY MEDICINE, Issue 4 2009Kevin Chu MBBS Abstract Objectives:, The objective was to investigate the efficacy of magnesium sulfate (MgSO4) in decreasing the ventricular rate in emergency department (ED) patients presenting with new-onset, rapid atrial fibrillation (AF). Methods:, A double-blinded, placebo-controlled randomized clinical trial was conducted in an adult university hospital. Patients aged ,18 years with AF onset of less than 48 hours and a sustained ventricular rate of >100 beats/min were randomized to either intravenous (IV) MgSO4 10 mmol or normal saline (NSal). Rhythm and instantaneous heart rate as measured by the monitor were recorded at baseline and every 15 minutes for 2 hours after starting the trial drug. Heart rate and rhythm were compared at 2 hours. A multilevel modeling analysis was performed to adjust for differences in baseline heart rate and any additional treatment and to examine changes in heart rate over time. Results:, Twenty-four patients were randomized to MgSO4 and 24 to NSal. Baseline heart rate was lower in the MgSO4 group (mean ± standard deviation [±SD] = 125 ± 24 vs. 140 ± 21 beats/min]. One and 3 patients in the MgSO4 and NSal groups, respectively, were given another antiarrhythmic or were electrically cardioverted within 2 hours after starting the trial drug. Heart rate (mean ± SD) at 2 hours in both MgSO4 (116 ± 30 beats/min) and NSal groups (114 ± 31 beats/min) decreased below their respective baseline levels. However, the rate of heart rate decrease across time did not differ between groups (p = 0.124). The proportion of patients who converted to sinus rhythm 2 hours post,trial drug did not differ (MgSO4 8.7% vs. NSal 25.0%, p = 0.25). Conclusions:, This study was unable to demonstrate a difference between IV MgSO4 10 mmol and saline placebo for reducing heart rate or conversion to sinus rhythm at 2 hours posttreatment in ED patients with AF of less than 48 hours duration. [source] Pneumonia Versus Aspiration Pneumonitis in Nursing Home Residents: Prospective Application of a Clinical AlgorithmJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 5 2005Joseph M. Mylotte MD Objectives: To prospectively evaluate a clinical algorithm for the diagnosis of pneumonitis and pneumonia in nursing home residents. Design: Prospective cohort study. Setting: Inpatient geriatrics unit. Participants: Nursing home residents admitted to the hospital with suspected pneumonia. Measurements: Identification of pneumonitis and pneumonia using the algorithm; medical record review and abstraction of clinical data; hospital outcome and length of stay. Results: One hundred seventy episodes of suspected pneumonia were screened with the algorithm and classified into four groups: 25% pneumonia, 28% aspiration pneumonitis of 24 hours or less duration, 12% aspiration pneumonitis of more than 24 hours' duration, and 35% an aspiration event without pneumonitis. Presenting symptoms and signs, laboratory tests, severity of illness measures, or serum C-reactive protein levels did not distinguish between the four groups. Those with an aspiration event without pneumonitis tended to be treated less often with antibiotic therapy after admission (P=.004) and after discharge (P=.01). Of those who survived, there was no significant difference in mean hospital length of stay between the four groups. There was no significant difference in the percentage of case fatality between the four groups, but those with aspiration pneumonitis of 24 hours or less duration and with an aspiration event without pneumonitis had a lower mortality than the other two groups. Conclusion: Distribution of episodes of suspected pneumonia by clinical category as determined using the algorithm was similar to that of the derivation study, as were case fatality rates in each category. These findings suggest that the algorithm may be useful for making the distinction between pneumonitis and pneumonia in nursing home residents; further studies are warranted. [source] Gender Disparity in Analgesic Treatment of Emergency Department Patients with Acute Abdominal PainACADEMIC EMERGENCY MEDICINE, Issue 5 2008Esther H. Chen MD Abstract Objectives:, Oligoanalgesia for acute abdominal pain historically has been attributed to the provider's fear of masking serious underlying pathology. The authors assessed whether a gender disparity exists in the administration of analgesia for acute abdominal pain. Methods:, This was a prospective cohort study of consecutive nonpregnant adults with acute nontraumatic abdominal pain of less than 72 hours' duration who presented to an urban emergency department (ED) from April 5, 2004, to January 4, 2005. The main outcome measures were analgesia administration and time to analgesic treatment. Standard comparative statistics were used. Results:, Of the 981 patients enrolled (mean age ± standard deviation [SD] 41 ± 17 years; 65% female), 62% received any analgesic treatment. Men and women had similar mean pain scores, but women were less likely to receive any analgesia (60% vs. 67%, difference 7%, 95% confidence interval [CI] = 1.1% to 13.6%) and less likely to receive opiates (45% vs. 56%, difference 11%, 95% CI = 4.1% to 17.1%). These differences persisted when gender-specific diagnoses were excluded (47% vs. 56%, difference 9%, 95% CI = 2.5% to 16.2%). After controlling for age, race, triage class, and pain score, women were still 13% to 25% less likely than men to receive opioid analgesia. There was no gender difference in the receipt of nonopioid analgesia. Women waited longer to receive their analgesia (median time 65 minutes vs. 49 minutes, difference 16 minutes, 95% CI = 3.5 to 33 minutes). Conclusions:, Gender bias is a possible explanation for oligoanalgesia in women who present to the ED with acute abdominal pain. Standardized protocols for analgesic administration may ameliorate this discrepancy. [source] | ||||||||||