Disentangling and modeling interactions in fish with burst-and-coast swimming reveal distinct alignment and attraction behaviors

We combine extensive data analyses with a modeling approach to measure, disentangle, and reconstruct the actual functional form of interactions involved in the coordination of swimming in Rummy-nose tetra (Hemigrammus rhodostomus). This species of fish performs burst-and-coast swimming behavior that consists of sudden heading changes combined with brief accelerations followed by quasi-passive, straight decelerations. We quantify the spontaneous stochastic behavior of a fish and the interactions that govern wall avoidance and the attraction and alignment to a neighboring fish, the latter by exploiting general symmetry constraints for the interactions. In contrast with previous experimental works, we find that both attraction and alignment behaviors control the reaction of fish to a neighbor. We then exploit these results to build a model of spontaneous burst-and-coast swimming and interactions of fish, with all parameters being estimated or directly measured from experiments. This model quantitatively reproduces the key features of the motion and spatial distributions observed in experiments with a single fish and with two fish. This demonstrates the power of our method that exploits large amounts of data for disentangling and fully characterizing the interactions that govern collective behaviors in animals groups. Moreover, we introduce the notions of "dumb" and "intelligent" active matter and emphasize and clarify the strong differences between them.Comment: Supplementary Information (PDF text + 5 videos) can be downloaded at http://www.lpt.ups-tlse.fr/spip.php?action=acceder_document&arg=2240&cle=f7d43896e78b1b15dff009dc7769eac3c956c76a&file=zip%2FSI_Web.zi

Access to wine experts' long-term memory to decipher an ill-defined sensory concept: The case of green red wine

The present study aims to understand an ill-defined sensory concept by a long-term memory-based strategy with Spanish winemakers from four wine regions using "green wine" as a case study. A total of 77 Spanish winemakers from four Spanish wine regions carried out a non-tasting free description task. The description task yielded terms belonging to two main categories including origin-related terms as well as sensory terms. Sensory terms belonged to aroma, taste, trigeminal, colour, multimodal and hedonic subcategories, which elucidates the multidimensionality of the studied concept. The most cited specific terms were "vegetal aroma", "bitter"and "unpleasant". Despite these commonalities, a certain idiosyncrasy linked to taste ("excessive sourness") and trigeminal ("astringency") subcategories as well as to wine components ("tannins") was evidenced as they were cited distinctly by experts belonging to separate wine regions. The capacity of approaches based on long-term memory to decipher multidimensional and ill-defined concepts is highlighted. The regional effect is also explained in terms of cognitive processes (i.e., knowledge and experience), which is linked to the use of sensory concepts by wine experts

Intensive family preservation services in Flanders:An outcome study

Set up as a one-group pre-test-post-test follow-up design, this study examines the outcomes of intensive family preservation services (IFPS) in Flanders addressing the following research questions: Does IFPS make a significant difference concerning (1) the interaction between parent and child? (2) social support as experienced by the parent? (3) stress and empowerment of the parent? and (4) the strengths and difficulties of the minor? Families seem to indicate that their family situation is more manageable, although still, professional help is needed. Parents feel more resilient about the situation and indicate that they can get along with their child better than before the crisis intervention. Parents still feel uncertain about the future and about their role as a parent. There seems to be no indications that their level and quality of social contacts have changed. Further research is suggested to provide more in-depth information about the conditions associated with processes of change during an IFPS intervention

The impact of the COVID-19 lockdown on depression sufferers:a qualitative study from the province of Zaragoza, Spain

Background and purpose The impact of COVID-19 and its control measures have exacerbated existing mental health conditions. Although the deleterious effects of mental health problems are well known, fewer studies have examined the links between the Social Determinants of Health (SDHs) and depression. This study provides insights into the relationship between SDHs and depression during the first strict lockdown in Spain, which lasted for a period of 7 weeks. Methods Fifty-two structured interviews were conducted with people diagnosed with depression during June 2020 in the province of Zaragoza (Spain). Interviews were conducted by telephone due to lockdown constraints. Inductive thematic content analysis was used to explore, develop, and define emergent categories of analysis, which were mapped against the SDH framework. Results Listening to people’s experiences of living with depression during lockdown provided insights into their concerns and coping strategies, which are greatly influenced by the conditions in which they live, their job and their age. Examples of these factors include access to and quality of physical spaces, including housing conditions and public spaces for socialising, social support, adverse working conditions which include caring responsibilities, and access to digital technologies and healthcare services. Conclusion SDHs have played a fundamental role in shaping people’s health and well-being during the COVID-19 pandemic, and this study has shown that they have a considerable effect on depression outcomes. Governments should consider implementing social welfare programs to tackle both psychosocial problems and material need during crisis situations

A group of two fish from the study species <i>Hemigrammus rhodostomus</i>.

<p>Credits to David Villa ScienceImage/CBI/CNRS, Toulouse, 2015.</p

Tracking.

<p>A: Background image in grayscale extracted from a video file of an experiment with the biggest tank (radius <i>R</i> = 353 mm). B: Arena estimated from user-defined mask. The outer bold circle of radius <i>R</i> is derived from the mask drawn by the user of the tracking software and defining the area where tracking occurs. Inner dashed circle has arbitrary radius 0.85×<i>R</i>. C: Estimated walls of the tank. D: Estimation of the radius along the circle. Red line stands for cubic spline smoothing and extrapolation over 2000 angular points. The signal is repeated 3 times to improve estimation on limits (at 0 and 2<i>π</i>). The second period is kept to compute wall distances. Estimation of local polynomials is done on 30 equally spaced ranges over one period. Dashed line shows the average radius. E: Distribution of estimated radius in pixels. Red line stands for estimation of the average, used as radius approximation to compute the ratio of pixel to millimeters (PixelsToMm ratio is equal to 0.71 for this video). F: Trajectory of a fish during 40 seconds (2000 points) reported inside the estimated walls. Filled and empty circle respectively stand for start and end points.</p

Average decay of the fish speed right after a kick.

<p>This decay can be reasonably described by an exponential decay with a relaxation time <i>τ</i>₀ ≈ 0.80s (violet dashed line).</p

Experimental conditions.

<p>Experimental conditions.</p