Nocturnal foraging lifts time-constraints in winter for migratory geese but hardly speeds up fueling

Climate warming advances the optimal timing of breeding for many animals. For migrants to start breeding earlier, a concurrent advancement of migration is required, including premigratory fueling of energy reserves. We investigate whether barnacle geese are time constrained during premigratory fueling and whether there is potential to advance or shorten the fueling period to allow an earlier migratory departure. We equipped barnacle geese with GPS trackers and accelerometers to remotely record birds’ behavior, from which we calculated time budgets. We examined how time spent foraging was affected by the available time (during daylight and moonlit nights) and thermoregulation costs. We used an energetic model to assess onset and rates of fueling and whether geese can further advance fueling by extending foraging time. We show that, during winter, when facing higher thermoregulation costs, geese consistently foraged at night, especially during moonlit nights, in order to balance their energy budgets. In spring, birds made use of the increasing day length and gained body stores by foraging longer during the day, but birds stopped foraging extensively during the night. Our model indicates that, by continuing nighttime foraging throughout spring, geese may have some leeway to advance and increase fueling rate, potentially reaching departure body mass 4 days earlier. In light of rapid climatic changes on the breeding grounds, whether this advancement can be realized and whether it will be sufficient to prevent phenological mismatches remains to be determined

Endoanal MRI of the anal sphincter complex: correlation with cross-sectional anatomy and histology

The purpose of this study was to correlate the in vivo endoanal MRI findings of the anal sphincter with the cross-sectional anatomy and histology. Fourteen patients with rectal tumours were examined with a rigid endoanal MR coil before undergoing abdominoperineal resection. In addition, 12 cadavers were used to obtain cross-sectional anatomical sections. The images were correlated with the histology and anatomy of the resected rectal specimens as well as with the cross-sectional anatomical sections of the 12 cadavers. The findings in 8 patients, 11 rectal preparations, and 10 cadavers, could be compared. In these cases, there was an excellent correlation between endoanal MRI and the cross-sectional cadaver anatomy and histology. With endoanal MRI, all muscle layers of the anal canal wall, comprising the internal anal sphincter, longitudinal muscle, the external anal sphincter and the puborectalis muscle wer

Optimizing imaging in suspected appendicitis (OPTIMAP-study): A multicenter diagnostic accuracy study of MRI in patients with suspected acute appendicitis. Study Protocol

<p>Abstract</p> <p>Background</p> <p>In patients with clinically suspected appendicitis, imaging is needed to substantiate the clinical diagnosis. Imaging accuracy of ultrasonography (US) is suboptimal, while the most accurate technique (CT) is associated with cancer related deaths through exposure to ionizing radiation. MRI is a potential replacement, without associated ionizing radiation and no need for contrast medium administration. If MRI is proven to be sufficiently accurate, it could be introduced in the diagnostic pathway of patients with suspected appendicitis, increasing diagnostic accuracy and improving clinical outcomes, without the risk of radiation induced cancer or iodinated contrast medium-related drawbacks. The multicenter OPTIMAP study was designed to estimate the diagnostic accuracy of MRI in patients with suspected acute appendicitis in the general population.</p> <p>Methods/Design</p> <p>Eligible for this study are consecutive patients presenting with clinically suspected appendicitis at the emergency department in six centers. All patients will undergo imaging according to the Dutch guideline for acute appendicitis: initial ultrasonography in all and subsequent CT whenever US does not confirm acute appendicitis. Then MRI is performed in all patients, but the results are not used for patient management. A final diagnosis assigned by an expert panel, based on all available information including 3-months follow-up, except MRI findings, is used as the reference standard in estimating accuracy. We will calculate the sensitivity, specificity, predictive values and inter-observer agreement of MRI, and aim to include 230 patients. Patient acceptance and total imaging costs will also be evaluated.</p> <p>Discussion</p> <p>If MRI is found to be sufficiently accurate, it could replace CT in some or all patients. This will limit or obviate the ionizing radiation exposure associated risk of cancer induction and contrast medium induced nephropathy with CT, preventing the burden and the direct and indirect costs associated with treatment. Based on the high intrinsic contrast resolution of MRI, one might envision higher accuracy rates for MRI than for CT. If so, MRI could further decrease the number of unnecessary appendectomies and the number of missed appendicitis cases.</p> <p>Trial registration</p> <p><b>NTR2148</b></p

Epinephrine in the heart: uptake and release, but no facilitation of norepinephrine release

BACKGROUND: Several studies have suggested that epinephrine augments the release of norepinephrine from sympathetic nerve terminals through stimulation of presynaptic receptors, but evidence pertaining to this mechanism in the heart is scarce and conflicting. Using the microdialysis technique in the porcine heart, we investigated whether epinephrine, taken up by and released from cardiac sympathetic nerves, can increase norepinephrine concentrations in myocardial interstitial fluid (NE(MIF)) under basal conditions and during sympathetic activation. METHODS AND RESULTS: During intracoronary epinephrine infusion of 10, 50, and 100 ng/kg per minute under basal conditions, large increments in interstitial (from 0.31+/-0.05 up to 140+/-30 nmol/L) and coronary venous (from 0.16+/-0.08 up to 228+/-39 nmol/L) epinephrine concentrations were found, but NE(MIF) did not change. Left stellate ganglion stimulation increased NE(MIF) from 3.4+/-0.5 to 8.2+/-1.5 nmol/L, but again, this increase was not enhanced by concomitant intracoronary epinephrine infusion. Intracoronary infusion of tyramine resulted in a negligible increase in epinephrine concentration in myocardial interstitial fluid (EPI(MIF)), whereas 30 minutes after infusion of epinephrine an increase of 9.5 nmol/L in EPI(MIF) was observed, indicating that epinephrine is taken up by and released from cardiac sympathetic neurons. Although 68% to 78% of infused epinephrine was extracted over the heart, the ratio of interstitial to arterial epinephrine concentrations was only approximately 20%, increasing to 29% with neuronal reuptake inhibition. CONCLUSIONS: Our findings demonstrate epinephrine release from cardiac sympathetic neurons, but they do not provide evidence that epinephrine augments cardiac sympathoneural norepinephrine release under basal conditions or during sympathetic activation

Contemporary review of risk-stratified management in acute uncomplicated and complicated diverticulitis

BACKGROUND: Acute colonic diverticulitis is a common clinical condition. Severity of the disease is based on clinical, laboratory, and radiological investigations and dictates the need for medical or surgical intervention. Recent clinical trials have improved the understanding of the natural history of the disease resulting in new approaches to and better evidence for the management of acute diverticulitis. METHODS: We searched the Cochrane Library (years 2004-2015), MEDLINE (years 2004-2015), and EMBASE (years 2004-2015) databases. We used the search terms "diverticulitis, colonic" or "acute diverticulitis" or "divertic*" in combination with the terms "management," "antibiotics," "non-operative," or "surgery." Registers for clinical trials (such as the WHO registry and the https://clinicaltrials.gov/) were searched for ongoing, recruiting, or closed trials not yet published. RESULTS: Antibiotic treatment can be avoided in simple, non-complicated diverticulitis and outpatient management is safe. The management of complicated disease, ranging from a localized abscess to perforation with diffuse peritonitis, has changed towards either percutaneous or minimally invasive approaches in selected cases. The role of laparoscopic lavage without resection in perforated non-fecal diverticulitis is still debated; however, recent evidence from two randomised controlled trials has found a higher re-intervention in this group of patients. CONCLUSIONS: A shift in management has occurred towards conservative management in acute uncomplicated disease. Those with uncomplicated acute diverticulitis may be treated without antibiotics. For complicated diverticulitis with purulent peritonitis, the use of peritoneal lavage appears to be non-superior to resection

Early identification of first-year students at risk of dropping out of high-school entry medical school: the usefulness of teachers' ratings of class participation

Dropping out from undergraduate medical education is costly for students, medical schools, and society in general. Therefore, the early identification of potential dropout students is important. The contribution of personal features to dropout rates has merited exploration. However, there is a paucity of research on aspects of student experience that may lead to dropping out. In this study, underpinned by theoretical models of student commitment, involvement, and engagement, we explored the hypothesis of using inferior participation as an indicator of a higher probability of dropping out in year 1. Class participation was calculated as an aggregate score based on teachers' daily observations in class. The study used a longitudinal dataset of six cohorts of high-school entry students (N = 709, 67% females) in one medical school with an annual intake of 120 students. The findings confirmed the initial hypothesis and showed that lower scores of class participation in year 1 added predictive ability to pre-entry characteristics (Pseudo-R2 raised from 0.22 to 0.28). Even though the inclusion of course failure in year 1 resulted in higher explanatory power than participation in class (Pseudo-R2 raised from 0.28 to 0.63), ratings of class participation may be advantageous to anticipate dropout identification, as those can be collected prior to course failure. The implications for practice are that teachers' ratings of class participation can play a role in indicating medical students who may eventually drop out. We conclude that the scores of class participation can contribute to flagging systems for the early detection of student dropouts.(undefined)info:eu-repo/semantics/acceptedVersio