scholarly journals Active sensing with light improves predator detection in a diurnal fish

2018 ◽  
Author(s):  
Matteo Santon ◽  
Pierre-Paul Bitton ◽  
Jasha Dehm ◽  
Roland Fritsch ◽  
Ulrike K. Harant ◽  
...  
Keyword(s):  
Field Experiment ◽  
Visual Detection ◽  
Average Distance ◽  
Detection Threshold ◽  
Active Sensing ◽  
Predator Detection ◽  
Light Organs ◽  
Anatomical Arrangement ◽  
Favorable Conditions

AbstractActive sensing by means of light is rare. In vertebrates, it is known only from chemiluminescent fish with light organs below their pupils, an anatomical arrangement that is ideal to generate eyeshine in the pupils of nearby organisms. Here, we test whether diurnal fish can achieve the same by redirecting sunlight through reflection instead. We recently showed that small (< 5 cm), benthic, marine triplefin fish actively redirect downwelling light using their iris. We hypothesized that this mechanism allows triplefins to improve detection of a cryptic organism by generating eyeshine in its pupil. Here, we tested this by attaching small dark hats to triplefins to shade their iris from downwelling light. Two controls consisted of triplefins with a clear or no hat. These treatments test the prediction that light redirection increases the visual detection ability of triplefins. To this end, we placed treated fish in a tank with a display compartment containing either a stone as the control stimulus, or a scorpionfish, i.e. a cryptic, motionless triplefin predator with retroreflective eyes. After overnight acclimatization, we determined the average distance triplefins kept from the display compartment over two days. Both in the laboratory (n = 15 replicates per treatment) and in a similar field experiment at 15 m depth (n = 43 replicates per treatment) fish kept longer distances from the scorpionfish than from the stone. This response varied between hat treatments: shaded triplefins stayed significantly closer to the scorpionfish in the laboratory and in one of two orientations tested in the field. A follow-up field experiment at 10 m depth revealed the immediate response of triplefins to a scorpionfish. At first, many individuals (n = 80) moved towards it, with shaded triplefins getting significantly closer. All individuals then gradually moved to a safer distance at the opposite half of the tank. Visual modelling supported the experimental results by showing that triplefins can redirect enough light with their iris to increase a scorpionfish’s pupil brightness above detection threshold at a distance of 7 cm under average field conditions and at more than 12 cm under favorable conditions. We conclude that triplefins are generally good in the visual detection of a cryptic predator, but can significantly improve this ability when able to redirect downwelling light with their iris and induce eyeshine in the predator’s pupil. We discuss the consequences of “diurnal active photolocation” for visual detection and camouflage among fish species.

Evaluation of Aortic Zone 2 Proximal Landing Accuracy During Thoracic Endovascular Aortic Repair Following Carotid-Subclavian Revascularization

2021 ◽  
Vol 55 (4) ◽  
pp. 355-360
Author(s):  
Sally H. J. Choi ◽  
Gary K. Yang ◽  
Keith Baxter ◽  
Joel Gagnon
Keyword(s):  
Carotid Artery ◽  
Common Carotid Artery ◽  
Retrospective Review ◽  
Average Distance ◽  
Thoracic Endovascular Aortic Repair ◽  
Endovascular Aortic Repair ◽  
Aortic Repair ◽  
Technical Accuracy ◽  
Corrective Procedures

Background: Adequate seal for thoracic endovascular aortic repair (TEVAR) commonly requires landing in zone 2, but can prove to be challenging due to the tortuous and angulated anatomy of the region. Objectives: Our objective was to determine the proximal landing accuracy of zone 2-targeted TEVARs following carotid-subclavian revascularization (CSR) and its impact on clinical outcomes. Methods: Retrospective review of patients that underwent CSR for zone 2 endograft delivery at a tertiary institute between January 2008 and March 2018 was conducted. Technical outcomes were assessed by examining the incidence of intraoperative corrective maneuvers, 1a endoleaks and reinterventions. Distance to target and incidence of LSA stump filling were examined as radiographic markers of landing accuracy. Results: Zone 2-targeted TEVAR with CSR was performed in 53 patients for treatment of dissections (49%), aneurysms (30%) or trauma (21%). Nine (17%) cases required intraoperative corrective procedures: 5 (9%) proximal cuffs due to type 1a endoleak and 4 (8%) left common carotid artery (LCCA) stenting due to inadvertent coverage. Cases performed using higher resolution hybrid fluoroscopy machine compared to mobile C-arm were associated with increased proximal cuff use (OR 8.8; 95% CI 1.2-62.4). Average distance between the proximal edge of the covered graft to LCCA was 8 ± 1 mm and larger distances were not associated with higher rates of 1a endoleak. Twenty-eight (53%) cases of antegrade LSA stump filling were noted on follow-up imaging, but were not associated with higher rates of reinterventions (OR 0.8, 95% CI [0.2-4.6]). Three (6%) patients had a stroke within 30 days and 4 (8%) patients expired within 1 month. Intraoperative corrective maneuvers, post-operative 1a endoleak and reinterventions were not associated with higher rates of stroke or mortality. Conclusion: Using current endografts and imaging modalities, zone 2-targeted TEVARs have suboptimal technical accuracy.

scholarly journals Surgical and Postoperative Evaluations of Rectal Adenomas Ecised With a Novel Proctoscope.

2020 ◽  
Author(s):  
Roberta Denise Alkmin Lopes Lima ◽  
Rogerio Serafim Parra ◽  
Marley Ribeiro Feitosa ◽  
Omar Féres ◽  
José Joaquim Ribeiro Rocha
Keyword(s):  
Operative Time ◽  
Average Distance ◽  
Economic Feasibility ◽  
Surgeon Experience ◽  
Average Operative Time ◽  
The Mean ◽  
Average Size ◽  
High Level ◽  
Complex Methods

Abstract Purpose Many transanal endoscopic surgeries require a high level of technical expertise and surgeon experience. Considering the economic feasibility of material acquisition and the technical feasibility of training and experience with complex methods, a simpler technique with available resources is relevant for the excision of rectal adenomas. This study presents the surgical and postoperative results achieved with a novel proctoscope using the transanal endoscopic technique to excise rectal adenomas. The results are compared to the results obtained with other currently employed transanal techniques. Methods We retrospectively investigated the medical records of patients who underwent transanal endoscopic operations from April 2000 to June 2018 at two tertiary referral centers for colorectal cancer. Results This study included 99 patients. The mean age was 65.3 ± 13.3 years. The average size of the adenomas was 4.6 ± 2.3 cm, and their average distance to the anal border was 5.6 ± 3.3 cm. The average operative time was 65.3 ± 41.7 min. In 48.5% of the operations, the specimen was fragmented, and in 59.6% of the cases, the microscopic margins were free. The rates of postoperative complications and relapse were 5% and 19%, respectively. The mean follow-up was 80 ± 61.5 months. Conclusions The described proctoscope proved to be a viable technique with results similar to other techniques, with the advantage that it allowed greater accessibility for surgeons. Therefore, its use could be implemented and become widespread in surgical practice.

Surgical Correction of Metopic Craniosynostosis: A 3-D Photogrammetric Analysis of Cranial Vault Outcomes

2018 ◽  
Vol 56 (2) ◽  
pp. 231-235 ◽  
Author(s):  
Olivia E. Linden ◽  
Vanessa M. Baratta ◽  
Jose A. Gonzalez ◽  
Margaret E. Byrne ◽  
Petra M. Klinge ◽  
...  
Keyword(s):  
Average Distance ◽  
Cranial Vault ◽  
3 Dimensional ◽  
Postoperative Time ◽  
The Face ◽  
Academic Teaching Hospital ◽  
One Year ◽  
Cranial Vault Remodeling ◽  
Metopic Craniosynostosis

Objective: To evaluate 3-dimensional (3-D) photogrammetry as a tool for assessing the postoperative head shape of patients who had undergone cranial vault remodeling for metopic synostosis. Design: We prospectively analyzed images of patients with metopic craniosynostosis who had undergone anterior cranial vault remodeling and age-matched controls. To ensure standardized facial orientation, each 3-D image was positioned to “best fit” the preoperative face by aligning 6 soft tissue landmarks. Forehead measurements were taken from a standardized position behind the surface of the face to landmarks placed in a ray configuration across the forehead. Setting: Academic teaching hospital. Patients, Participants: Thirteen pediatric patients with metopic craniosynostosis who had undergone anterior cranial vault remodeling and age-matched controls. Interventions: Images were taken preoperatively, immediately postoperatively, and over 1-year postoperatively. Main Outcome Measures: Forehead contours preoperatively and postoperatively, with statistics performed using a multivariate analysis of variance shape analysis. Results: Mean postoperative follow-up was 1.8 (0.6) years. The average distance from the origin to forehead landmarks was 55.1 (3.4) mm preoperatively, 59.3 (0.7) mm immediate postoperatively, 59.1 (1.0) mm 1-year postoperatively, and 59.4 (0.6) mm in controls. Postoperative metopic forehead contours varied significantly from preoperative contours ( P < .01), while there was no statistical difference between the 2 postoperative time points ( P = .70). One-year postoperative patients were not significantly different from their age-matched controls ( P > .99). Conclusions: Preoperative metopic forehead contours varied significantly from postoperative contours. Cranial reconstructions approximated the foreheads of normal controls, and reconstructions were stable at more than 1-year follow-up.

scholarly journals Radiostereometric Analysis of Subpectoral versus Suprapectoral Biceps Tenodesis with Interference Screw Fixation

2019 ◽  
Vol 7 (3_suppl2) ◽  
pp. 2325967119S0019
Author(s):  
Richard N. Puzzitiello ◽  
Avinesh Agarwalla ◽  
Joseph N. Liu ◽  
Gregory L. Cvetanovich ◽  
Anirudh K. Gowd ◽  
...  
Keyword(s):  
Screw Fixation ◽  
Average Distance ◽  
Biceps Tendon ◽  
Interference Screw ◽  
Biceps Tenodesis ◽  
Radiostereometric Analysis ◽  
Distal Migration ◽  
Interference Screw Fixation ◽  
Subpectoral Biceps Tenodesis

Objectives: Biceps tenodesis is performed with increasing frequency for various pathologies of the long head biceps tendon (LHBT). Multiple surgical techniques and devices for tenodesis have been described with favorable outcomes. The subpectoral approach provides adequate clinical outcomes; furthermore, recent research suggests that similar outcomes can be achieved via arthroscopic suprapectoral biceps tenodesis. Previous studies have compared the biomechanical profile of suprapectoral and subpectoral biceps tenodesis. There is a paucity of data regarding the biomechanical behavior and construct stability of suprapectoral and subpectoral biceps tenodesis in vivo. The purpose of this investigation is to quantify and compare the behavior of the biceps tenodesis construct in arthroscopic suprapectoral (ASPBT) and open subpectoral (OSPBT) techniques, with radiostereometric analysis (RSA). Methods: This is a prospective cohort study comparing migration of the biceps tendon after suprapectoral and subpectoral biceps tenodesis with Polyetheretherketone (PEEK) interference screw fixation. Thirty consecutive patients were allocated to the subpectoral group, follow by thirty consecutive patients to the suprapectoral group. Patients aged 18-65 years with symptomatic biceps tendinopathy, anterior intertubercular groove tenderness, and positive biceps tension tests were included in the investigation. Patients undergoing revision biceps tenodesis, shoulder arthroplasty, or ruptured LHBT were excluded. A mini skin staple, functioning as a radiostereometric marker, was placed longitudinally within the tendon prior to final fixation with interference screw. Staple stability was confirmed with a hemostat to gravity. The distance from the most proximal portion of the mini skin staple and the most proximal aspect of the humeral head was measured. Following final fixation with an interference screw, AP radiographs were obtained intraoperatively. Follow-up radiographs were one week and 12 weeks post-operatively. A paired and non-paired students t-test were utilized to assess for intra-group and inter-group changes, respectively. Results: A total of 60 consecutive patients (30 per group) were enrolled and available for follow-up imaging at 1 and 12 weeks postoperatively. The average age was 43.5±10.5 years, average BMI was 28.3±5.4, and 50% of the patients were females. Groups were similar with respect to patient demographics and concomitant procedures (P>.05). In the OSPBT group, the average distance of the radiostereometic marker to the proximal humeral head increased on by 26.0 mm (SD, 15.7) from the immediate post-operative radiograph to 3 months postoperatively (P=0.002). In the ASPBT group, the average distance also significantly increased by 24.7 mm (SD, 14.9) from the immediate post-operative radiograph to 3-months postoperatively (P=0.001). The change in distal migration between the ASPBT and OSPBT was not found to be statistically significant (P> 0.05). Conclusion: Biceps tenodesis performed with a PEEK tenodesis screw results in significant distal migration of the biceps tendon by 3 months post-operatively; however, there was no significant difference in distal migration between the OSPBT and ASPBT groups.

Discontinuation of Imatinib Therapy After Achieving a Molecular Response in Chronic Myeloid Leukemia Patients.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 859-859 ◽  
Author(s):  
Francois-Xavier Mahon ◽  
Delphine Rea ◽  
Francois Guilhot ◽  
Francoise Huguet ◽  
Franck Emmanuel Nicolini ◽  
...  
Keyword(s):  
Pilot Study ◽  
Chronic Myeloid Leukemia ◽  
Nk Cells ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Single Agent ◽  
Detection Threshold ◽  
Molecular Response ◽  
Number Of Patients

Abstract Abstract 859 Background Imatinib (IM) has greatly improved survival rates in chronic myeloid leukemia* (*CML). However, all patients (pts) must continue treatment for an unknown period of time. A pilot study of the first pts who discontinued IM therapy was previously reported (Rousselot et al. Blood 2007;109:58–60). The multicentre study Stop Imatinib (STIM) was initiated in July 2007 in order to evaluate the persistence of complete molecular remission (CMR) after stopping IM, and to determine the factors that could be associated with CMR persistence. Methods Inclusion criteria were IM treatment duration of at least 3 years and sustained CMR. Sustained CMR was defined as BCR-ABL/ABL levels below a detection threshold corresponding to a 5-log reduction (undetectable signal using RQ-PCR) for at least 2 years. Molecular relapse, defined as RQ-PCR positivity, was taken into account if confirmed in two successive assessments. In cases of molecular relapse, pts were re-challenged with IM at 400 mg daily. Results From the pilot study, 8 among 15 patients are still in CMR with a median follow up of 42 months (range 37-49). The number of patients enrolled in the STIM study was 69. 34 patients had received interferon alpha (IFNa) prior to IM and 35 pts were de novo. Median follow-up (range) was 17 months (6-24). 37 pts relapsed (loss of CMR) within the first 6 months and two patient relapsed after more than 6 months (M7 ,M18). At M12, the probability of remaining in CMR was 45% (95% CI: 33-56%). For previously treated with IFN (n=34) this probability was 44% (95% CI: 27-59%) versus 46% (95% CI: 29-61%) for de novo pts (p=0.93, overall). All patients in molecular relapse were sensitive again after imatinib re-challenge (decreasing BCR-ABL level, achievement CMR again). Male pts had a better probability of survival without molecular relapse (p=0.02) and a trend was observed for the low Sokal risk group (p = 0.06). Peripheral NK cells counts prior to IM discontinuation were significantly lower in relapse pts (mainly cytotoxic cells CD56dim) as compared to the non relapse pts(p=0.005). Conclusions We have confirmed that CMR can be sustained after discontinuation of imatinib with a long follow-up, particularly in male patients and in pts with cytotoxic NK cells in their peripheral blood. Using stringent criteria, it is possible to stop treatment in patients with sustained CMR, even in those treated with IM as a single agent. (ClinicalTrials.gov number, NCT00478985 [ClinicalTrials.gov]) Disclosures: Mahon: Amgen: Honoraria; Novartis Pharma: Consultancy, Honoraria, Research Funding; Alexion: Consultancy, Honoraria. Guilhot:Novartis Pharma: Consultancy, Honoraria; BMS: Consultancy, Honoraria.

scholarly journals For Your Eyes Only: A Field Experiment on Nudging Hygienic Behavior

2020 ◽  
Vol 11 ◽  
Author(s):  
Hilde Mobekk ◽  
Dag Olav Hessen ◽  
Asle Fagerstrøm ◽  
Hanne Jacobsen
Keyword(s):  
Field Experiment ◽  
Experimental Studies ◽  
Individual Choice ◽  
Hygienic Behavior ◽  
Follow Up Study ◽  
Reversal Design ◽  
Hygiene Compliance ◽  
The Impact ◽  
Over Time

These days many gyms and fitness centers are closed to reduce transmission of the SARS-CoV-2 virus in society. The gym is an environment rich in microorganisms, and careful hygiene is a necessity to keep infections at bay. Exercise centers strive for better hygiene compliance among their members. This effort has become essential in light of the current pandemic. Several experimental studies show that others’ physical presence, or the “illusion” of being watched, may alter behavior. This article reports on a natural field experiment testing one specific social nudge intended to increase gym members’ hygienic behavior. The study was conducted before the SARS-COV-2 pandemic. A picture of “observing eyes” was attached to paper dispensers and cleanser spray bottles at two different gyms in Norway. A reversal design, also called an ABA design, with and without the nudge’s presence, was used to investigate the impact on gym members’ hygienic behavior. A follow-up study was conducted in one of the centers to investigate whether the nudge stimuli would function over time. The study included 254 individual choice situations during nine observation sessions conducted over 9 weeks. The results from both centers provide evidence of a strong effect of the nudge. However, the effect decreased during the follow-up study. These findings support previous research indicating that human behavior is influenced by the presence of implicit observation cues – in this case – observing eyes. However, insights into the long-term effect of implicit observation cues are still needed since the salience of the stimuli faded over time.

scholarly journals Changing the taste of apples by eurythmic treatments

2019 ◽  
Vol 4 (1) ◽  
pp. 460-464
Author(s):  
Eckart Grundmann ◽  
Tanja Baumgartner
Keyword(s):  
Laboratory Test ◽  
Field Experiment ◽  
Fruit Quality ◽  
Sugar Content ◽  
Agricultural Systems ◽  
Human Movements ◽  
To Come ◽  
Performing Art ◽  
The Impact

AbstractEurythmy is a performing art based on anthroposophy which tries to make non-visible forces visible by human movements. According to the concept of anthroposophy a eurythmist is capable to come into an exchange with the life forces of organisms through his movements. In a field experiment – executed by the Institute ArteNova in cooperation with an apple farmer – a eurythmist treated trees of two apple varieties with a sequence of eurythmic gestures to observe the impact on the fruit quality. The apples showed no differences in the laboratory test of sugar content and firmness. In the sensory test, significant differences could be found in several parameters like freshness, crunchiness or the total judgement. The results present a basic effect of human movements on the taste of plants. Furthermore, it was possible to find appropriate movements for pre-determined aims. Eurythmic movements could be seen as a possible method for agricultural systems which refuse pesticides and other synthetic substances. Follow-up experiments with different varieties, fruits, and places should verify the effects.

Sign in / Sign up

Export Citation Format

Share Document