Speed-cohesion trade-offs in collective decision making in ants and the concept of precision in animal behaviour

In decision making, speed-accuracy trade-offs are well known and often inevitable because accuracy depends on being well informed and gathering information takes time. However, trade-offs between speed and cohesion, that is the degree to which a group remains together as a single entity, as a result of their decision making, have been comparatively neglected. We combine theory and experimentation to show that in decision-making systems, speed-cohesion trade-offs are a natural complement to speed-accuracy trade-offs and are therefore of general importance. We then analyse the decision performance of 32 rock ant, Temnothorax albipennis, colonies in experiments in which accuracy of collective decision making was held constant, but time urgency varied. These experiments reveal for the first time an adaptive speed-cohesion trade-off in collective decision making and how this is achieved. In accord with different time constraints, colonies can decide quickly, at the cost of social unity, or they can decide slowly with much greater cohesion. We discuss the similarity between cohesion and the term precision as used in statistics and engineering. This emphasizes the generality of speed versus cohesion/precision trade-offs in decision making and decision implementation in other fields within animal behaviour such as sexually selected motor displays and even certain aspects of birdsong. We also suggest that speed versus precision trade-offs may occur when individuals within a group need to synchronize their activity, and in collective navigation, cooperative hunting and in certain escape behaviours.

Gender-related psychological and behavioural correlates of pubertal timing in a national sample of Swiss adolescents.

The potential consequences of early and late puberty on the psychological and behavioural development of the adolescent are not well known. This paper presents focused analyses from the Swiss SMASH study, a self-administered questionnaire survey conducted among a representative sample of 7488 adolescents from 16 to 20 years old. Data from participants reporting early or late timing of puberty were compared with those reporting average timing of maturation. Early maturing girls reported a higher rate of dissatisfaction with body image (OR=1.32) and functional symptoms (OR=1.52) and reported engaging in sexual activity more often (OR=1.93). Early maturing boys reported engaging in exploratory behaviours (sexual intercourse, legal and illegal substance use) at a significantly higher rate (OR varying between 1.4 and 1.99). Both early and late maturing boys reported higher rates of dysfunctional eating patterns (OR=1.59 and 1.38, respectively), victimisation (OR=1.61 and 1.37, respectively) and depressive symptoms (OR=2.11 and 1.53, respectively). Clinicians should take into account the pubertal stage of their patients and provide them, as well as their parents, with appropriate counselling in the field of mental health and health behaviour.

Personality trait risk factors for attempted suicide among young women with eating disorders.

OBJECTIVE: - Clinical observations and a review of the literature led us to hypothesize that certain personality and character traits could provide improved understanding, and thus improved prevention, of suicidal behaviour among young women with eating disorders. METHOD: - The clinical group consisted of 152 women aged between 18 and 24 years, with DSM-IV anorexia nervosa/restrictive type (AN-R = 66), anorexia nervosa/purging type (AN-P = 37), bulimia nervosa/non-purging type (BN-NP = 9), or bulimia nervosa/purging type (BN-P = 40). The control group consisted of 140 subjects. The assessment measures were the Minnesota Multiphasic Personality Inventory-second version (MMPI-2) scales and subscales, the Beck Depression Inventory (BDI) used to control for current depressive symptoms, plus a specific questionnaire concerning suicide attempts. RESULTS: - Suicide attempts were most frequent in subjects with purging behaviour (30.0% for BN-P and 29.7% for AN-P). Those attempting suicide among subjects with eating disorders were mostly students (67.8%). For women with AN-R the scales for 'Depression' and 'Antisocial practices' represented significant suicidal risk, for women with AN-P the scales for 'Hysteria', 'Psychopathic deviate', 'Shyness/Self-consciousness', 'Antisocial Practices', 'Obsessiveness' and 'Low self-esteem' were risk indicators and for women with BN-P the 'Psychasthenia', 'Anger' and 'Fears' scales were risk indicators. CONCLUSION: - This study provides interesting results concerning the personality traits of young women with both eating disorders and suicidal behaviour. Students and those with purging behaviour are most at risk. Young women should be given more attention with regard to the risk of suicide attempts if they: (a). have AN-R with a tendency to self-punishment and antisocial conduct, (b). have AN-P with multiple physical complaints, are not at ease in social situations and have antisocial behaviour, or (c). if they have BN-P and tend to be easily angered with obsessive behaviour and phobic worries. The MMPI-2 is an interesting assessment method for the study of traits indicating a risk of suicidal behaviour in young subjects, after controlling for current depressive pathology.

Comparison of plantar pressure distribution in adolescent runners at low vs. high running velocity

This study aimed to compare foot plantar pressure distribution while jogging and running in highly trained adolescent runners. Eleven participants performed two constant-velocity running trials either at jogging (11.2 ± 0.9 km/h) or running (17.8 ± 1.4 km/h) pace on a treadmill. Contact area (CA in cm(2)), maximum force (F(max) in N), peak pressure (PP in kPa), contact time (CT in ms), and relative load (force time integral in each individual region divided by the force time integral for the total plantar foot surface, in %) were measured in nine regions of the right foot using an in-shoe plantar pressure device. Under the whole foot, CA, F(max) and PP were lower in jogging than in running (-1.2% [p<0.05], -12.3% [p<0.001] and -15.1% [p<0.01] respectively) whereas CT was higher (+20.1%; p<0.001). Interestingly, we found an increase in relative load under the medial and central forefoot regions while jogging (+6.7% and +3.7%, respectively; [p<0.05]), while the relative load under the lesser toes (-8.4%; p<0.05) was reduced. In order to prevent overloading of the metatarsals in adolescent runners, excessive mileage at jogging pace should be avoided.

Training needs in adolescent medicine of practising doctors: a Swiss national survey of six disciplines.

OBJECTIVE: To assess and compare the training needs in adolescent medicine of doctors within 6 specialties as a basis for the development of pre/postgraduate and continuing medical education (CME) training curricula. DESIGN: Cross-sectional postal survey. SETTING: Switzerland. PARTICIPANTS: National, representative, random sample of 1857 practising doctors in 6 disciplines (general practitioners, paediatricians, gynaecologists, internists, psychiatrists, child psychiatrists) registered with the Swiss Medical Association. MAIN OUTCOME MEASURES: Perceived importance of and training interest in 35 topics related to adolescent medicine listed in a self-administered, anonymous questionnaire. RESULTS: A total of 1367 questionnaires were returned, representing a response rate of 73.9%. Clear interest in adolescent medicine was reported by 62.1% of respondents. Topics perceived to be the most important in everyday practice were functional symptoms (71.4%), acne (67.1%), obesity (64.6%), depression-anxiety (68.1%) and communication with adolescents (61.7%). Differences between disciplines were especially marked for gynaecologists, who expressed interest almost exclusively in medical topics specific to their field. In contrast, other disciplines commonly reported a keen interest in psychosocial problems. Accordingly, interest in further training was expressed mostly for functional symptoms (62.4%), eating disorders (56.3%), depression-anxiety (53.7%) and obesity (52.6%). Issues related to injury prevention, chronic disease and confidentiality were rated as low priorities. CONCLUSIONS: Regardless of discipline, Swiss primary care doctors expressed a strong interest in adolescent medicine. Continuing medical education courses should include both interdisciplinary courses and discipline-specific sessions. Further training should address epidemiological and legal/ethical issues (e.g. injury prevention, confidentiality, impact of chronic conditions).

Place illusion and plausibility can lead to realistic behaviour in immersive virtual environments

In this paper address we the question as to why participants tend to respond realistically to situations and events portrayed within an Immersive Virtual Reality (IVR) system. The idea is put forward, based on experience of a large number of experimental studies, that there are two orthogonal components that contribute to this realistic response. The first is"being there", often called"presence", the qualia of having a sensation of being in a real place. We call this Place Illusion (PI). Second, Plausibility Illusion (Psi) refers to the illusion that the scenario being depicted is actually occurring. In the case of both PI and Psi the participant knows for sure that that they are not"there" and that the events are not occurring. PI is constrained by the sensorimotor contingencies afforded by the virtual reality system. Psi is determined by the extent to which the system can produce events that directly relate to the participant, and the overall credibility of the scenario being depicted in comparison with expectations. We argue that when both PI and Psi occur, participants will respond realistically to the virtual reality.

Performance analysis of software run-time behaviour using 3D-visualisation

Monimutkaisen tietokonejärjestelmän suorituskykyoptimointi edellyttää järjestelmän ajonaikaisen käyttäytymisen ymmärtämistä. Ohjelmiston koon ja monimutkaisuuden kasvun myötä suorituskykyoptimointi tulee yhä tärkeämmäksi osaksi tuotekehitysprosessia. Tehokkaampien prosessorien käytön myötä myös energiankulutus ja lämmöntuotto ovat nousseet yhä suuremmiksi ongelmiksi, erityisesti pienissä, kannettavissa laitteissa. Lämpö- ja energiaongelmien rajoittamiseksi on kehitetty suorituskyvyn skaalausmenetelmiä, jotka edelleen lisäävät järjestelmän kompleksisuutta ja suorituskykyoptimoinnin tarvetta. Tässä työssä kehitettiin visualisointi- ja analysointityökalu ajonaikaisen käyttäytymisen ymmärtämisen helpottamiseksi. Lisäksi kehitettiin suorituskyvyn mitta, joka mahdollistaa erilaisten skaalausmenetelmien vertailun ja arvioimisen suoritusympäristöstä riippumatta, perustuen joko suoritustallenteen tai teoreettiseen analyysiin. Työkalu esittää ajonaikaisesti kerätyn tallenteen helposti ymmärrettävällä tavalla. Se näyttää mm. prosessit, prosessorikuorman, skaalausmenetelmien toiminnan sekä energiankulutuksen kolmiulotteista grafiikkaa käyttäen. Työkalu tuottaa myös käyttäjän valitsemasta osasta suorituskuvaa numeerista tietoa, joka sisältää useita oleellisia suorituskykyarvoja ja tilastotietoa. Työkalun sovellettavuutta tarkasteltiin todellisesta laitteesta saatua suoritustallennetta sekä suorituskyvyn skaalauksen simulointia analysoimalla. Skaalausmekanismin parametrien vaikutus simuloidun laitteen suorituskykyyn analysoitiin.

Pédiatrie 5. Approche ciblée de l'ostéoporose chez l'enfant et l'adolescent [Targeted approach to osteoporosis for children and teenagers].

The osteoporosis of the child and the teenager is a pathological reality; its multifactorial pathogenesis often requires a collaborative approach and multidisciplinary. The osteoporosis characterized by a reduction in the bone mineral density is not a uniform pathology; it must be dealt with on all the levels by analyzing the factors of risks, by giving itself the diagnostic means and while insisting on the importance of a preventive approach as well as therapeutic.

Estudi de prevalença de sobrepès i obesitat en la població adolescent de Girona

L’obesitat infantil, és un dels problemes de salut pública més greus del segle XXI, on la prevalença ha augmentat de manera alarmant a nivell mundial. Aquesta es defineix com una malaltia crònica i multifactorial, que sol iniciar-se en la infantesa i a l’adolescència. L’objectiu principal d’aquest estudi és conèixer la prevalença de sobrepès i obesitat en la població adolescent de Girona, i relacionar amb aquesta, els hàbits alimentaris, els hàbits d’activitat física, l’entitat de l’institut-escola, hores de son i nivell màxim d’estudis dels progenitors. Material i mètodes: Estudi descriptiu, observacional i transversal sobre una mostra de la població adolescent de Girona de 14 a 16 anys (n=185), els quals se’ls va administrar un qüestionari on es van recollir les variables relacionades amb l’estudi. L’obesitat i el sobrepès es van definir com valors de l’índex de massa corporal iguals o superiors als valors dels percentils 97 i 85, respectivament, de les taules de referencia de la OMS de 2007. Resultats: La prevalença de sobrepès i d’obesitat en la població adolescent de Girona és del 20% i del 3,78%, respectivament. El sobrepès i l’obesitat (23,78%) ha afectat més al sexe masculí (27,7%) respecte el femení (19,8%). S’ha establert relació significativa entre la prevalença de sobrepès i obesitat amb el nivell màxim d’estudis dels progenitors. Hi ha més prevalença de sobrepès i obesitat a l’institut públic en vers el privat amb un 26,7% respecte el 18,5%. Conclusions: Segons la bibliografia consultada, la població adolescent de Girona presenta més elevada la prevalença de sobrepès però no pel que fa la prevalença d’obesitat

Consumers' use of nutrition-related endorsement symbol to help their purchase decisions: An extension of the theory of planned behaviour

Tutkimuksessa haluttiin selvittää, mitkä tekijät vaikuttavat ravintoon liittyvän suositusmerkin käyttöön kuluttajan ostopäätöksen apuna. Tutkimuksen viitekehyksen pohjaksi valittiin suunnitellun toiminnan teoria, joka on osoittautunut selittämään hyvin useaa ravintoon- ja terveyteen liittyvää käyttäytymistä. Tutkimustoteutettiin kyselytutkimuksella, jonka aineisto kerättiin Internetissä julkaistulla kyselylomakkeella. Tulokset osoittivat, että kuluttajan aikomus käyttää suositusmerkkiä oli mallin vahvin selittäjä. Lisäksi merkin käyttöä selitti kuluttajan kokema sisäinen kontrolli, johon ulkoinen kontrolli vahvasti vaikuttaa. Ostopäätössitoutumisen havaittiin vaikuttavan aikomuksen ja todellisen merkin käytön väliseen yhteyteen. Yleisesti tulokset osoittivat, että kuluttajilla on aikomusta käyttää merkkiä, mutta todellinen käyttö on huomattavasti vähäisempää.

Propionic acidemia: clinical course and outcome in 55 pediatric and adolescent patients.

BACKGROUND: Propionic acidemia is an inherited disorder caused by deficiency of propionyl-CoA carboxylase. Although it is one of the most frequent organic acidurias, information on the outcome of affected individuals is still limited. STUDY DESIGN/METHODS: Clinical and outcome data of 55 patients with propionic acidemia from 16 European metabolic centers were evaluated retrospectively. 35 patients were diagnosed by selective metabolic screening while 20 patients were identified by newborn screening. Endocrine parameters and bone age were evaluated. In addition, IQ testing was performed and the patients' and their families' quality of life was assessed. RESULTS: The vast majority of patients (>85%) presented with metabolic decompensation in the neonatal period. Asymptomatic individuals were the exception. About three quarters of the study population was mentally retarded, median IQ was 55. Apart from neurologic symptoms, complications comprised hematologic abnormalities, cardiac diseases, feeding problems and impaired growth. Most patients considered their quality of life high. However, according to the parents' point of view psychic problems were four times more common in propionic acidemia patients than in healthy controls. CONCLUSION: Our data show that the outcome of propionic acidemia is still unfavourable, in spite of improved clinical management. Many patients develop long-term complications affecting different organ systems. Impairment of neurocognitive development is of special concern. Nevertheless, self-assessment of quality of life of the patients and their parents yielded rather positive results.