Evaluation of Two Methods to Estimate and Monitor Bird Populations

Background: Effective management depends upon accurately estimating trends in abundance of bird populations over time, and in some cases estimating abundance. Two population estimation methods, double observer (DO) and double sampling (DS), have been advocated for avian population studies and the relative merits and short-comings of these methods remain an area of debate. Methodology/Principal Findings: We used simulations to evaluate the performances of these two population estimation methods under a range of realistic scenarios. For three hypothetical populations with different levels of clustering, we generated DO and DS population size estimates for a range of detection probabilities and survey proportions. Population estimates for both methods were centered on the true population size for all levels of population clustering and survey proportions when detection probabilities were greater than 20%. The DO method underestimated the population at detection probabilities less than 30 % whereas the DS method remained essentially unbiased. The coverage probability of 95 % confidence intervals for population estimates was slightly less than the nominal level for the DS method but was substantially below the nominal level for the DO method at high detection probabilities. Differences in observer detection probabilities did not affect the accuracy and precision of population estimates of the DO method. Population estimates for the DS method remained unbiased as the proportion of units intensively surveyed changed, but the variance of th

Selective serotonin reuptake inhibitors in the treatment of generalized anxiety disorder

Selective serotonin reuptake inhibitors have proven efficacy in the treatment of panic disorder, obsessive–compulsive disorder, post-traumatic stress disorder and social anxiety disorder. Accumulating data shows that selective serotonin reuptake inhibitor treatment can also be efficacious in patients with generalized anxiety disorder. This review summarizes the findings of randomized controlled trials of selective serotonin reuptake inhibitor treatment for generalized anxiety disorder, examines the strengths and weaknesses of other therapeutic approaches and considers potential new treatments for patients with this chronic and disabling anxiety disorder

Radiatively heated, protoplanetary discs with dead zones. I. Dust settling and thermal structure of discs around M stars

The irradiation of protoplanetary discs by central stars is the main heating mechanism for discs, resulting in their flared geometric structure. In a series of papers, we investigate the deep links between 2D self-consistent disc structure and planetary migration in irradiated discs, focusing particularly on those around M stars. In this first paper, we analyse the thermal structure of discs that are irradiated by an M star by solving the radiative transfer equation by means of a Monte Carlo code. Our simulations of irradiated hydrostatic discs are realistic and self-consistent in that they include dust settling with multiple grain sizes (N=15), the gravitational force of an embedded planet on the disc, and the presence of a dead zone (a region with very low levels of turbulence) within it. We show that dust settling drives the temperature of the mid-plane from an $r^{-3/5}$ distribution (well mixed dust models) toward an $r^{-3/4}$. The dead zone, meanwhile, leaves a dusty wall at its outer edge because dust settling in this region is enhanced compared to the active turbulent disc at larger disc radii. The disc heating produced by this irradiated wall provides a positive gradient region of the temperature in the dead zone in front of the wall. This is crucially important for slowing planetary migration because Lindblad torques are inversely proportional to the disc temperature. Furthermore, we show that low turbulence of the dead zone is self-consistently induced by dust settling, resulting in the Kelvin-Helmholtz instability (KHI). We show that the strength of turbulence arising from the KHI in the dead zone is $\alpha=10^{-5}$.Comment: 19 pages, 20 figures, 3 tables, accepted for publication in MNRA

Typhoid ulcer causing life-threatening bleeding from Dieulafoy's lesion of the ileum in a seven-year-old child: a case report

<p>Abstract</p> <p>Introduction</p> <p>We describe a case of rare complication of typhoid fever in a seven-year-old child and review the literature with regard to other rare causes of bleeding per rectum. Dieulafoy's lesion is an uncommon but important cause of recurrent gastrointestinal bleeding. Dieulafoy's lesion located extragastrically is rare. We report a case of typhoid ulcer with Dieulafoy's lesion of the ileum causing severe life-threatening bleeding and discuss the management of this extremely uncommon entity.</p> <p>Case presentation</p> <p>As a complication of typhoid fever, a seven-year-old Kurdish girl from Northern Iraq developed massive fresh bleeding per rectum. During colonoscopy and laparotomy, she was discovered to have multiple bleeding ulcers within the Dieulafoy's lesion in the terminal ileum and ileocecal region.</p> <p>Conclusion</p> <p>Although there is no practical way of predicting the occurrence of such rare complications, we emphasize in this case report the wide array of pathologies that can result from typhoid fever.</p

Amplification of HER2 is a marker for global genomic instability

<p>Abstract</p> <p>Background</p> <p>Genomic alterations of the proto-oncogene c-erbB-2 (HER-2/neu) are associated with aggressive behavior and poor prognosis in patients with breast cancer. The variable clinical outcomes seen in patients with similar HER2 status, given similar treatments, suggests that the effects of amplification of HER2 can be influenced by other genetic changes. To assess the broader genomic implications of structural changes at the HER2 locus, we investigated relationships between genomic instability and HER2 status in patients with invasive breast cancer.</p> <p>Methods</p> <p>HER2 status was determined using the PathVysion^®assay. DNA was extracted after laser microdissection from the 181 paraffin-embedded HER2 amplified (n = 39) or HER2 negative (n = 142) tumor specimens with sufficient tumor available to perform molecular analysis. Allelic imbalance (AI) was assessed using a panel of microsatellite markers representing 26 chromosomal regions commonly altered in breast cancer. Student t-tests and partial correlations were used to investigate relationships between genomic instability and HER2 status.</p> <p>Results</p> <p>The frequency of AI was significantly higher (<it>P </it>< 0.005) in HER2 amplified (27%) compared to HER2 negative tumors (19%). Samples with HER2 amplification showed significantly higher levels of AI (<it>P </it>< 0.05) at chromosomes 11q23, 16q22-q24 and 18q21. Partial correlations including ER status and tumor grade supported associations between HER2 status and alterations at 11q13.1, 16q22-q24 and 18q21.</p> <p>Conclusion</p> <p>The poor prognosis associated with HER2 amplification may be attributed to global genomic instability as cells with high frequencies of chromosomal alterations have been associated with increased cellular proliferation and aggressive behavior. In addition, high levels of DNA damage may render tumor cells refractory to treatment. In addition, specific alterations at chromosomes 11q13, 16q22-q24, and 18q21, all of which have been associated with aggressive tumor behavior, may serve as genetic modifiers to HER2 amplification. These data not only improve our understanding of HER in breast pathogenesis but may allow more accurate risk profiles and better treatment options to be developed.</p

Characterization of Pseudomonas aeruginosa isolates: Occurrence rates, antimicrobial susceptibility patterns, and molecular typing in the global SENTRY Antimicrobial Surveillance Program, 1997-1999

During 1997–1999, a total of 70,067 isolates (6631 Pseudomonas aeruginosa isolates) were analyzed in the SENTRY program by geographic region and body site of infection. The respiratory tract was the most common source of P. aeruginosa. P. aeruginosa isolation rates increased during the study interval. Europe was the only region to show a significant decline in β-lactam and aminoglycoside susceptibility rates. There was a reduction in the rates of susceptibility of Canadian isolates to imipenem and of Latin American isolates to meropenem. A total of 218 multidrug-resistant P. aeruginosa isolates (MDR-PSA; resistant to piperacillin, ceftazidime, imipenem, and gentamicin) were observed; MDR-PSA occurrence rates (percentages of all isolates) ranged from 8.2% (Latin America) to 0.9% (Canada). No antimicrobial inhibited >50% of MDR-PSA strains. Molecular characterization of selected, generally resistant strains was performed. Isolates showing unique ribogroups were found in Europe, Latin America, and the United States, but clonal spread was documented in several medical centers.A. C. Gales, R. N. Jones, J. Turnidge, R. Rennie, and R. Rampha

The Course of Habituation of the Proboscis Extension Reflex Can Be Predicted by Sucrose Responsiveness in Drosophila

The proboscis extension reflex (PER) is triggered when insects’ gustatory receptors contact appetitive stimuli, so it provides a behavioral readout for perceptual encoding of tastants. Research on the experience dependent modulation of PER in Drosophila has been hindered by the difficulty of obtaining reliable measures of memory-driven change in PER probability in the background of larger changes induced by physiological state. In this study, we showed that the course of PER habituation can be predicted by the degree of sucrose responsiveness in Drosophila. We assessed early response parameters, including the number of proboscis extensions and labellar movements in the first five trials, the trial to start responding, and the trial to make the first stop to quantify responsiveness, which predicted the upcoming pattern of both the short-term and 1 hour memory of PER habituation for individual flies. The cAMP signaling pathway mutant rutabaga displayed deficits in attunement of perceptual salience of sucrose to physiological demands and stimulus-driven sensitization

Interaction effects on common measures of sensitivity:Choice of measure, type I error, and power

Here we use simulation to assess previously unaddressed problems in the assessment of statistical interactions in detection and recognition tasks. The proportion of hits and false-alarms made by an observer on such tasks is affected by both their sensitivity and bias, and numerous measures have been developed to separate out these two factors. Each of these measures makes different assumptions regarding the underlying process and different predictions as to how false-alarm and hit rates should covary. Previous simulations have shown that choice of an inappropriate measure can lead to inflated type I error rates, or reduced power, for main effects, provided there are differences in response bias between the conditions being compared. Interaction effects pose a particular problem in this context. We show that spurious interaction effects in analysis of variance can be produced, or true interactions missed, even in the absence of variation in bias. Additional simulations show that variation in bias complicates patterns of type I error and power further. This under-appreciated fact has the potential to greatly distort the assessment of interactions in detection and recognition experiments. We discuss steps researchers can take to mitigate their chances of making an error

Biological-effective versus conventional dose volume histograms correlated with late genitourinary and gastrointestinal toxicity after external beam radiotherapy for prostate cancer: a matched pair analysis

BACKGROUND: To determine whether the dose-volume histograms (DVH's) for the rectum and bladder constructed using biological-effective dose (BED-DVH's) better correlate with late gastrointestinal (GI) and genitourinary (GU) toxicity after treatment with external beam radiotherapy for prostate cancer than conventional DVH's (C-DVH's). METHODS: The charts of 190 patients treated with external beam radiotherapy with a minimum follow-up of 2 years were reviewed. Six patients (3.2%) were found to have RTOG grade 3 GI toxicity, and similarly 6 patients (3.2%) were found to have RTOG grade 3 GU toxicity. Average late C-DVH's and BED-DVH's of the bladder and rectum were computed for these patients as well as for matched-pair control patients. For each matched pair the following measures of normalized difference in the DVH's were computed: (a) δ(AUC )= (Area Under Curve [AUC] in grade 3 patient – AUC in grade 0 patient)/(AUC in grade 0 patient) and (b) δ(V60 )= (Percent volume receiving = 60 Gy [V60] in grade 3 patient – V60 in grade 0 patient)/(V60 in grade 0 patient). RESULTS: As expected, the grade 3 curve is to the right of and above the grade 0 curve for all four sets of average DVH's – suggesting that both the C-DVH and the BED-DVH can be used for predicting late toxicity. δ(AUC )was higher for the BED-DVH's than for the C-DVH's – 0.27 vs 0.23 (p = 0.036) for the rectum and 0.24 vs 0.20 (p = 0.065) for the bladder. δ(V60 )was also higher for the BED-DVH's than for the C-DVH's – 2.73 vs 1.49 for the rectum (p = 0.021) and 1.64 vs 0.71 (p = 0.021) for the bladder. CONCLUSIONS: When considering well-established dosimetric endpoints used in evaluating treatment plans, BED-DVH's for the rectum and bladder correlate better with late toxicity than C-DVH's and should be considered when attempting to minimize late GI and GU toxicity after external beam radiotherapy for prostate cancer