Search

Bats are well known for species richness and ecological diversity, and thus, they provide a good opportunity to study relationships and interaction between species. To assess interactions, we consider distinct traits that are probably to be triggered by niche shape and evolutionary processes. We present data on the trophic niche differentiation between two sympatric European trawling bat species, Myotis dasycneme and Myotis daubentonii, incorporating a wide spectrum of methodological approaches. We measure morphological traits involved in foraging and prey handling performance including bite force, weightlifting capacity and wing morphology. We then measure resulting prey consumption using both morphological and molecular diet analyses. These species closely resemble each other in morphological traits, however, subtle but significant differences were apparent in bite force and lift capacity, which are related to differences in basic body and head size. Both morphological and molecular diet analyses show strong niche overlap. We detected subtle differences in less frequent prey items, as well as differences in the exploitation of terrestrial and aquatic-based prey groups. Myotis dasycneme feeds more on aquatic prey, like Chironomidae and their pupal stages, or on the aquatic moth Acentria ephemerella. Myotis daubentonii feeds more on terrestrial prey, like Brachycera, or Coleoptera. This suggests that these bats use different microhabitats within the habitat where they co-occur. [ABSTRACT FROM AUTHOR]

The rate of sensory update is one of the most important parameters of any sensory system. The acquisition rate of most sensory systems is fixed and has been optimized by evolution to the needs of the animal. Echolocating bats have the ability to adjust their sensory update rate which is determined by the intervals between emissions - the inter-pulse intervals (IPI). The IPI is routinely adjusted, but the exact factors driving its regulation are unknown. We use on-board audio recordings to determine how four species of echolocating bats with different foraging strategies regulate their sensory update rate during commute flights. We reveal strong correlations between the IPI and various echolocation and movement parameters. Specifically, the update rate increases when the signals' peak-energy frequency and intensity increases while the update rate decreases when flight speed and altitude increases. We suggest that bats control their information update rate according to the behavioral mode they are engaged in, while always maintaining sensory continuity. Specifically, we suggest that bats apply two modes of attention during commute flights. Our data moreover suggests that bats emit echolocation signals at accurate intervals without the need for external feedback., (© 2023. The Author(s).)

Introduction: The human intestinal tract reacts to extensive resection with spontaneous intestinal adaptation. We analyzed whether gene expression analyses or intestinal permeability (IP) testing could provide biomarkers to describe regulation mechanisms in the intestinal barrier in short bowel syndrome (SBS) patients during adaptive response or treatment with the glucagon-like peptide-2 analog teduglutide., Methods: Relevant regions of the GLP-2 receptor gene were sequenced. Gene expression analyses and immunohistochemistry were performed from mucosal biopsies. IP was assessed using a carbohydrate oral ingestion test., Results: The study includes 59 SBS patients and 19 controls. Increases in gene expression with teduglutide were received for sucrase-isomaltase, sodium/glucose cotransporter 1, and calcium/calmodulin serine protein kinase. Mannitol recovery was decreased in SBS but elevated with teduglutide (Δ 40%), showed a positive correlation with remnant small bowel and an inverse correlation with parenteral support., Conclusions: Biomarkers predicting clinical and functional features in human SBS are very limited. Altered specific gene expression was shown for genes involved in nutrient transport but not for genes controlling tight junctions. However, mannitol recovery proved useful in describing the absorptive capacity of the gut during adaptation and treatment with teduglutide.

Background: International practice guidelines for high-stool-output (HSO) management in short bowel syndrome (SBS) are available, but data on implementation are lacking. This study describes the approach used to manage HSO in SBS patients across different global regions., Methods: This is an international multicenter study evaluating medical management of HSO in SBS patients using a questionnaire survey. Thirty-three intestinal-failure centers were invited to complete the survey as one multidisciplinary team., Results: Survey response rate was 91%. Dietary recommendations varied based on anatomy and geographic region. For patients without colon-in-continuity (CiC), clinical practices were generally consistent with ESPEN guidelines, including separation of fluid from solid food (90%), a high-sodium diet (90%), and a low-simple-sugar diet (75%). For CiC patients, practices less closely followed guidelines, such as a low-fat diet (35%) or a high-sodium diet (50%). First-line antimotility and antisecretory medications were loperamide and proton-pump inhibitors. Other therapeutic agents (e.g., pancreatic enzymes and bile acid binders) were utilized in real-world practices, and usage varied based on intestinal anatomy., Conclusion: Expert centers largely followed published HSO-management guidelines for SBS patients without CiC, but clinical practices deviated substantially for CiC patients. Determining the reasons for this discrepancy might inform future development of practice guidelines.

Background: Quality of life (QoL) data of chronic intestinal failure (cIF) patients treated with the GLP-2 analogue teduglutide are scarce. This study aims to analyze QoL changes over time in teduglutide-treated patients and compare the results to a matched non-treated cIF control group in a real-world setting., Methods: QoL data (SF-36 and SBS-QoL TM ) were obtained from adult cIF patients being treated with teduglutide and compared to previously collected QoL data from a PNLiver trial (DRKS00010993), during which patients had been therapy naive. The dataset was then extended by a pairwise matched control group (non-teduglutide-treated PNLiver trial patients) and follow-up data from this group were collected accordingly., Results: Median teduglutide treatment duration and the follow-up period of controls were both 4.3 years. SBS-QoL TM subscales and the SBS-QoL TM sum score showed significant improvements over time in teduglutide-treated patients, as well as for the SF-36 physical and mental component summary scores (all p < 0.02), while non-treated patients showed no significant changes in any of the mentioned scores. Significant differences of QoL changes between treated and non-treated patients were seen for both SF-36 summary scores ( p = 0.031 and 0.012)., Conclusions: We herein demonstrate for the first time that QoL significantly improved during teduglutide treatment in SBS-cIF patients in a real-world setting compared to individually matched non-treated SBS-cIF patients, indicating relevant clinical benefits.

Predators that target multiple prey types are predicted to switch foraging modes according to prey profitability to increase energy returns in dynamic environments. Here, we use bat-borne tags and DNA metabarcoding of feces to test the hypothesis that greater mouse-eared bats make immediate foraging decisions based on prey profitability and changes in the environment. We show that these bats use two foraging strategies with similar average nightly captures of 25 small, aerial insects and 29 large, ground-dwelling insects per bat, but with much higher capture success in the air (76%) vs ground (30%). However, owing to the 3-20 times larger ground prey, 85% of the nightly food acquisition comes from ground prey despite the 2.5 times higher failure rates. We find that most bats use the same foraging strategy on a given night suggesting that bats adapt their hunting behavior to weather and ground conditions. We conclude that these bats use high risk-high gain gleaning of ground prey as a primary foraging tactic, but switch to aerial hunting when environmental changes reduce the profitability of ground prey, showing that prey switching matched to environmental dynamics plays a key role in covering the energy intake even in specialized predators., Competing Interests: LS, AH, SG, HG, MJ, YY, PM No competing interests declared, (© 2023, Stidsholt et al.)

Background & Aims: An international, multidisciplinary management working group (MWG) convened to review clinically useful short bowel syndrome (SBS) literature and identify gaps and inconsistencies in the management of adults with SBS., Methods: Using nominal group technique for literature review, key publications were identified, discussed, and ranked by importance related to management of SBS. Gaps in management recommendations for SBS were identified upon critical review of the selected publications., Results: Five guidelines, seven review articles, one series of six articles, and one single center series were selected and prioritized for their importance to SBS management. Evaluation of the articles by the MWG identified ten gaps and opportunities to standardize and improve SBS management., Conclusion: The main practice areas in need of more definitive guidelines are the management of high stool output and strategies to improve absorption of medications, nutrients, and fluids. An understanding of current real-world clinical practices related to these gaps could allow for development of best practice standards and improve patient-focused care., Competing Interests: Declaration of competing interest MB-H provided clinical medical consultancy at the Digestive Disease Center, Bispebjerg University Hospital, Copenhagen, Denmark and is employed by Zealand Pharma as a research and development medical advisor. Zealand Pharma provided logistic support of working group meetings., (Copyright © 2023 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)

Background & Aims: Teduglutide is a Glucagon-like peptide-2 (GLP-2) agonist indicated for the treatment of patients with parenteral support (PS) dependent short bowel syndrome (SBS) with chronic intestinal failure (cIF). Its application is accompanied by a structured nation-wide home-care service program in Germany. We investigated care characteristics and outcome parameters in a clinical real-world observational setting., Methods: Data generated within a therapy-accompanying home-care service program for adult SBS-cIF patients were analyzed retrospectively for patients treated up to 1 year (data cut: April 2020)., Results: In total, 52 teduglutide-treated patients were included by 6 German cIF centers. At teduglutide administration start, 49/52 patients were on PS, 3 of them without macronutrients. The majority of patients received individualized parenteral nutrition (PN) (n = 32/46), while 13/46 were on commercial premixed bags. PS application was done by patients themselves (37%), home-care nurses (19%), relatives (8%) or by a combination of those (16%). In patients with PS dependency at baseline and available follow-up data (n = 40-44), teduglutide treatment resulted in significantly reduced PN days, caloric needs, infusion time, and infusion volume after 6 and 12 months. After 1 year, reduction of infusion time was positively correlated with a reduction of PN calories and volume; 30 patients (68%) were responders (PS-volume reduction ≥20%), and 6 patients (14%) were completely weaned off PS. Sleep disturbances per night were significantly reduced after 3 months of treatment and stool characteristics improved in consistency and significantly in frequency, while meal frequency remained stable., Conclusions: Teduglutide treatment associated reduction in PS volume and calories was accompanied by reduced infusion days, infusion times, sleep disturbances, stable oral intake surrogates, and improved stool characteristics, all of these potential parameters for improving quality of life. Furthermore, analyzed care characteristics reflect SBS-cIF treatment as a complex, resource-intensive and demanding task for both, healthcare system and patients., Competing Interests: Declaration of Competing Interest S. Greif J. Wehkamp, and S. Maasberg have been consultants for Shire Pharmaceuticals (Takeda), Y. Zopf, H. Herrmann and M. von Websky received lecture honoraria from Shire Pharmaceuticals (Takeda), Y. Zopf and H. Herrmann received support for attending meetings and/or travel from Shire Pharmaceuticals (Takeda), E. Blüthner has received Grant/Research Support from Takeda, payment from Takeda for presentations and lectures and for participation in advisory boards, U.-F. Pape and G. Lamprecht have been a site investigator of the STEPS-trial and have received consultant and lecture honoraria from Shire Pharmaceuticals (Takeda), as well as research funding from Shire Pharmaceuticals (Takeda). I. Schiefke, S. Fusco, T. Jacob, J. Büttner, F. Tacke have nothing to declare., (Copyright © 2022 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)

Mycotic coronary aneurysms are rare, with potentially fatal complications. The treatment of choice is surgical intervention. We present a case of a mycotic coronary aneurysm secondary to a catheter-related bloodstream infection, failed surgical treatment, and eventual treatment with percutaneous coil embolization., (©Copyright 2021 by University Health Partners of Hawai‘i (UHP Hawai‘i).)

Prey that are signalling in aggregation become more conspicuous with increasing numbers and tend to attract more predators. Such grouping may, however, benefit prey by lowering the risk of being captured because of the predator's difficulty in targeting individuals. Previous studies have investigated anti-predatory benefits of prey aggregation using visual predators, but it is unclear whether such benefits are gained in an auditory context. We investigated whether katydids of the genus Mecopoda gain protection from their acoustically eavesdropping bat predator Megaderma spasma when calling in aggregation. In a choice experiment, bats approached calls of prey aggregations more often than those of prey calling alone, indicating that prey calling in aggregation are at higher risk. In prey capture tasks, however, the average time taken and the number of flight passes made by bats before capturing a katydid were significantly higher for prey calling in aggregation than when calling alone, indicating that prey face lower predation risk when calling in aggregation. Another common anti-predatory strategy, calling from within vegetation, increased the time taken by bats to capture katydids calling alone but did not increase the time taken to capture prey calling from aggregations. The increased time taken to capture prey calling in aggregation compared with solitary calling prey offers an escape opportunity, thus providing prey that signal acoustically in aggregations with anti-predatory benefits. For bats, greater detectability of calling prey aggregations is offset by lower foraging efficiency, and this trade-off may shape predator foraging strategies in natural environments., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)

How animals extract information from their surroundings to guide motor patterns is central to their survival. Here, we use echo-recording tags to show how wild hunting bats adjust their sensory strategies to their prey and natural environment. When searching, bats maximize the chances of detecting small prey by using large sensory volumes. During prey pursuit, they trade spatial for temporal information by reducing sensory volumes while increasing update rate and redundancy of their sensory scenes. These adjustments lead to very weak prey echoes that bats protect from interference by segregating prey sensory streams from the background using a combination of fast-acting sensory and motor strategies. Counterintuitively, these weak sensory scenes allow bats to be efficient hunters close to background clutter broadening the niches available to hunt for insects., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)

Background: Sensory systems acquire both external and internal information to guide behavior. Adjustments based on external input are much better documented and understood than internal-based sensory adaptations. When external input is not available, idiothetic-internal-cues become crucial for guiding behavior. Here, we take advantage of the rapid sensory adjustments exhibited by bats in order to study how animals rely on internal cues in the absence of external input. Constant frequency echolocating bats are renowned for their Doppler shift compensation response used to adjust their emission frequency in order to optimize sensing. Previous studies documented the importance of external echoes for this response., Results: We show that the Doppler compensation system works even without external feedback. Bats experiencing accelerations in an echo-free environment exhibited an intact compensation response. Moreover, using on-board GPS tags on free-flying bats in the wild, we demonstrate that the ability to perform Doppler shift compensation response based on internal cues might be essential in real-life when echo feedback is not available., Conclusions: We thus show an ecological need for using internal cues as well as an ability to do so. Our results illustrate the robustness of one particular sensory behavior; however, we suggest this ability to rely on different streams of information (i.e., internal or external) is probably relevant for many sensory behaviors.