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In cooperatively breeding species, group members may derive multiple benefits from helping to raise other individuals' offspring, yet not all individuals do so. In this study, we tested predictions from the "kin selection", "pay-to-stay", "group augmentation" and "skills" hypotheses, to explain why group members feed nestlings of breeding placid greenbuls (Phyllastrephus placidus). In our study population, about 70% of the breeding pairs were accompanied by subordinates, and in 60% of these cases at least one subordinate helped in provisioning nestlings. In total, 80% of the subordinates were related to one or both breeders. In accordance with the "kin selection" hypothesis, and contrary to the "pay-to-stay" hypothesis, all the helpers were first-order kin of the breeding female (although relatedness to the breeding male did not explain variation in helping) and the presence of helpers was associated with increased survival of the breeding pair. However, the propensity to help varied among group members, as 46% of group members related to the breeding female did not feed nestlings. Younger helpers fed offspring more often than older ones, supporting the "skills" and "group augmentation" hypotheses. However, support for the "group augmentation" hypothesis was mixed since subordinate sex and group size did not explain additional variation in helping propensity and effort. We argue that in addition to indirect and direct benefits, also the costs of helping as well as other types of helping aside from provisioning must be considered to better understand variation in helping behavior. Relatedness is thought to be an important factor explaining helping at the nest by non-breeding group members. We show that placid greenbul helpers are always related to the breeding females, supporting this view. However, many related groups members never helped suggesting that other factors shape helping decision in this species.

Females are predicted to adjust their reproductive investment to optimize the trade-off between current and future reproduction. In many cooperatively breeding birds, females have been shown to reduce their investment both pre- and posthatching in response to the presence of food-provisioning helpers. However, in species where not all group members help during the posthatching stage, it is currently unclear to which social cues (i.e. group size versus number of helpers) females should tune their investment. Here, we used the cooperatively breeding placid greenbul, Phyllastrephus placidus, as a model species to examine whether and how group size and number of helpers affect female investment in eggs and food provisioning. We found that females used a contrasting strategy pre- and posthatching in response to different social cues: they laid larger eggs in larger groups while reducing their feeding rate when assisted by more helpers. We also found that fledging success increased with group size and that nestlings raised in groups with helpers fledged with longer wings but found no relation between condition of the young and number of helpers. Since the perceived contrasting investment strategies may have several underlying causes, we conclude that predicting the influence of social conditions on maternal investment may be more challenging than previously believed. (c) 2023 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

To investigate the participation restriction of adult spinal deformity (ASD) patients, and its relation with the impairments in body structure and function, and activity limitation, as this important information regarding the individual's perspective on the social impact of the disease on their life is presently not captured.Forty-three ASD patients participated in the study and completed the impact on participation and autonomy (IPA) questionnaire to assess the level of participation. Activity limitations and impairments were measured with the Balance Evaluation Systems Test (BESTest) and Scoliosis Research Society-22r (SRS-22). Also, age, body height, body weight, BMI, Mini-mental state examination and Cumulative Illness Rating Scale were assessed. A univariate linear regression analysis was conducted to investigate the relationship between the IPA and the independent variables, whereas a multivariate analysis identified the significant predictive variables for the IPA questionnaire.The univariate analysis identified performance on the BESTest and SRS-22 as significantly (p 0.001) related to the IPA questionnaire. The multiple regression analysis revealed that the performance on BESTest (p = 0.073) and SRS-22 (p 0.001) independently predicted the IPA questionnaire, explaining 73.5% of its variance.To fully understand the impact of ASD on the individual's functioning, disability and health-status, it is suggested that questionnaires on participation to society should be considered, together with clinical postural tests (e.g. the BESTest) and questionnaires related to HRQOL (e.g. the SRS-22), in the ASD care path. This additional information should allow the surgeon to make a more informed selection of surgical patients.

Socially monogamous females regularly mate with males outside the pair bond. The prevailing explanation for this behavior is that females gain genetic benefits resulting from increased fitness of extra-pair offspring. Furthermore, because of the risk of reduced paternal care in response to cuckoldry, females are expected to seek extra-pair copulations when they can rear offspring with little help from their social partner ("constrained female" hypothesis). We tested these hypotheses and analyzed variation in paternal care in the Afrotropical, facultative cooperative breeding placid greenbul (Phyllastrephus placidus). Overall, approximately 50% of the offspring resulted from extra-pair (and extra-group) mating. Identified extra-pair males were in most cases neighboring dominant males, yet never within-group subordinates. As predicted by the constrained female hypothesis, the occurrence of extra-pair paternity (EPP) increased with the number of cooperative helpers (and not with total group size). However, dominant males did not adjust their food provisioning rates in response to EPP. Although extra-pair males were more strongly related to the dominant female and less heterozygous than the latter's social mate, this did not result in more inbred extra-pair offspring, likely because identified extra-pair males were not representative of the extra-pair male population. While earlier studies on EPP mainly focused on male genetic quality, results from this study provide evidence that female's social context may affect extra-pair strategies too. Lay Summary: In many bird species, females mate with males outside the pair bond. Because of the risk of reduced paternal care in response to cuckoldry, females are expected to seek extra-pair copulations when they can rear offspring with little help from their social partner. We showed in the cooperative breeding placid greenbul that extra-pair paternity increased with the number of helpers in accordance with the hypothesis that helpers liberate females from their dependency on paternal care.

STUDY DESIGN: Prospective cross-sectional case-control study design. OBJECTIVE: This study aims to analyze the relation between balance control as well as health-related quality of life (HRQOL) in patients with adult spinal deformity (ASD), with a novel gravity line (GL)-related 3D spinal alignment parameter, the transverse gravitational deviation index (TGDI), defined to quantify the transverse plane position of any vertebra with respect to the GL. SUMMARY OF BACKGROUND DATA: Demographic data and balance control have both been identified as important determinants of HRQOL in ASD patients during a preoperative setting. Therefore, a better understanding of the relation between spinal alignment and balance is required. METHODS: After informed consent, 15 asymptomatic healthy volunteers (mean age 60.1 ± 11.6 years old) and 55 ASD patients (mean age 63.5 ± 10.1 years old) were included. Relation between performance on BESTest as well as core outcome measures index (COMI) with spinopelvic alignment was explored using General Linear Modeling (GLM). A P-value ≤0.05 was considered statistically significant. RESULTS: The L3 TGDI was identified to relate to balance control in the total ASD population after correction for confounding demographic factors (P = 0.001; adjusted R = 0.500) and explained 19% of the observed variance in balance performance. In addition, COMI is related to L3 TGDI in a subgroup of ASD patients with combined coronal and sagittal malalignment of L3 (P = 0.027; slope B = 0.047), despite significant influence of age (P = 0.020). CONCLUSION: In ASD patients with a combined coronal and sagittal malalignment of the L3 vertebra, both the level of balance impairment as well as HRQOL are related to the distance component of the L3 TGDI, that is, the offset between the center of the L3 vertebral body and the GL in the transverse plane. LEVEL OF EVIDENCE: 2. ispartof: SPINE vol:45 issue:1 pages:E25-E36 ispartof: location:United States status: published

It remains poorly understood how effects of anthropogenic activity, such as large-scale habitat fragmentation, impact sociality in animals. In cooperatively breeding species, groups are mostly formed through delayed offspring dispersal, and habitat fragmentation can affect this process in two opposite directions. Increased habitat isolation may increase dispersal costs, promoting delayed dispersal. Alternatively, reduced patch size and quality may decrease benefits of philopatry, promoting dispersal. Here, we test both predictions in a cooperatively breeding bird (placid greenbul, Phyllastrephus placidus ) from an Afrotropical cloud forest archipelago. Males born in fragmented forest dispersed about 1 year earlier than those born in continuous forest. Contrary to females, males also started to reproduce earlier and mostly settled within their natal patch. Females only rarely delayed their dispersal for more than 1 year, both in fragmented and continuous forests. Our results suggest that early male dispersal and reproduction is jointly driven by a decrease in the value of the natal territory and an increase in local breeding opportunities in fragmented forest. While plasticity in dispersal strategies of cooperative breeders in response to anthropogenic change is believed to optimize reproduction-survival trade-offs, to what extent it shapes the ability of species to respond to rapid environmental change remains to be studied.

Human activities impact upon natural habitats used by birds for breeding and foraging, and lead to changes in the composition and spatial distribution of predator communities, mainly through loss, fragmentation and disturbance of formerly pristine habitat. Yet possible fitness consequences of such changes through impacts on bird nest‐site selection remain poorly known. Here we study nest‐site selection and reproductive success of Placid Greenbuls Phyllastrephus placidus in the Taita Hills, southeast Kenya. We show that habitat features associated with nest‐site selection by this insectivorous, open‐cup‐nesting bird species vary among forest fragments that are exposed to different levels of habitat disturbance. Such differences in sites selected for breeding result from a plastic response to fragment‐specific conditions or may be driven by fragment‐specific variation in the distribution and availability of certain habitat features. Given the overall high nest predation rates in our study area, we expected variation in nest‐site selection to correlate with reproductive success and nestling condition, but detected no such relationship. Because predator density and nest predation rates may vary strongly in space and time, a better understanding of spatio‐temporal variation in predator communities is needed to assess the possible adaptive value of nest‐site selection strategies for reducing the high predation rates that are typical for this and many other open‐cup‐nesting tropical passerines.

Personalised dosing of performance-enhancing food supplements is a hot topic. &beta, alanine is currently dosed using a fixed dose, however, evidence suggests that this might favour light compared to heavy subjects. A weight-relative dose seems to reverse this problem. In the present study, a novel dosing strategy was tested. A fragmented dose, composed of a fixed fragment of 800 mg and a weight-relative fragment of 10 mg/kg body weight, was compared to a fixed dose of 1600 mg and a weight-relative dose of 20 mg/kg body weight in a cohort of 20 subjects with a body weight ranging 48&ndash, 139 kg (79.9 &plusmn, 24.4 kg). The results show that, following a fragmented dose, the influence of body weight on the pharmacokinetic response (iAUC) over a 210 min period was absent (r = &minus, 0.168, p = 0.478), in contrast to the fixed or weight-relative dose. The pharmacokinetic response also seemed more homogenous (CV% = 26%) following a fragmented dose compared to the fixed (33%) and the weight-relative dose (31%). The primary advantage of the easy-to-calculate fragmented dosing strategy is that it does not systematically favour or impair a certain weight group. Thorough dosage studies are lacking in the current field of sports and food supplements, therefore similar considerations can be made towards other (ergogenic) food supplements.

abstract not available

Prospective single-center study.Study investigates how dynamic balance performance complements 2D static radiographic measurements and demographics in terms of understanding health-related quality of life in adult spinal deformity (ASD) patients.Recent insights suggest that demographic variables have a stronger impact on health-related quality of life than 2D radiographic spinopelvic parameters in ASD patients.Nine healthy volunteers and 36 ASD patients following inclusion criteria were recruited. Demographics, Scoliosis Research Society Score-22r (SRS-22r), Oswestry Disability Index (ODI), Core Outcome Measures Index (COMI), 2D radiographic spinopelvic measurements, and performance on Balance Evaluation Systems Test (BESTest), and Trunk Control Measurement Scale (TCMS) were determined for each subject. Nonparametric tests, Spearman correlations, univariate, and stepwise-like linear multivariate regression analysis were performed.BESTest and TCMS had significant lower values in the ASD group versus the control group (P = 0.000). In the ASD group, Cumulative Illness Rating Scale (CIRS) correlated fair to ODI, COMI (0.441 ≥ r ≥ 0.383, P 0.021) and to SRS-22-r (r = -0.335, P = 0.046), Mini Mental State Examination correlated fair to COMI (r = -0.352, P = 0.035), "Pelvic Incidence minus Lumbar Lordosis" correlated fair to ODI (r = 0.361, P = 0.031), BESTest correlated moderate to ODI and COMI (r ≤ -0.505; P ≤ 0.002), TCMS correlated fair to ODI (r = -0.356; P = 0.033). CIRS and BESTest were significant predictive variables for COMI based on univariate analysis in ASD patients. Multivariate regression analysis including demographics, 2D static radiographic parameters, and dynamic balance scales identified BESTest as single independent variable (P = 0.000) to predict COMI (adjusted R = 0.285) in ASD patients.BESTest has a higher potential than demographic and 2D radiographic spinopelvic parameters to predict quality of life in ASD patients. Further research is necessary to identify the impact of ASD on quality of life.3.

For avian group living to be evolutionary stable, multiple fitness benefits are expected. Yet, the difficulty of tracking fledglings, and thus estimating their survival rates, limits our knowledge on how such benefits may manifest postfledging. We radio-tagged breeding females of the Afrotropical cooperatively breeding Placid greenbul (Phyllastrephus placidus) during nesting. Tracking these females after fledging permitted us to locate juvenile birds, their parents, and any helpers present and to build individual fledgling resighting datasets without incurring mortality costs or causing premature fledging due to handling or transmitter effects. A Bayesian framework was used to infer age-specific mortality rates in relation to group size, fledging date, maternal condition, and nestling condition. Postfledging survival was positively related to group size, with fledglings raised in groups with four helpers showing nearly 30% higher survival until independence compared with pair-only offspring, independent of fledging date, maternal condition or nestling condition. Our results demonstrate the importance of studying the early dependency period just after fledging when assessing presumed benefits of cooperative breeding. While studying small, mobile organisms after they leave the nest remains highly challenging, we argue that the telemetric approach proposed here may be a broadly applicable method to obtain unbiased estimates of postfledging survival.

The assessment of sound pressure levels generated by submerged structures is part of problems regarding underwater noise pollution. The growing number of offshore constructions related to energy generation by wind farms increases the importance of these studies. The understanding of physical mechanisms responsible for this radiation should allow us to reduce the noise by refining the construction of structures. The object of the present work is the study of underwater acoustic radiation of tube vibrations. The results presented were obtained on two stainless steel tubes. These tubes are placed vertically into water. The vibrations are generated by a shock obtained using a hammer with a force sensor hitting the tube on the emerged part. The vibrations of the tube placed in the air and in water are measured using accelerometers. The influence of water on the modes of resonances observed is then highlighted. The acoustic radiation measurements are made by a hydrophone located at a few meter distance of the tube. Results are presented as time signals and spectra and are compared to results of analytical and numerical calculations. Relationships between the resonances of the tube and the acoustic radiation in water are then interpreted.

1. Universite Bordeaux 1. OASU/EPOC UMR 5805. Avenue des facultes, 33405 Talence, France. parisot@epoc.u-bordeaux1.fr ; p.bonneton@epoc.u-bordeaux1.fr ; n.bonneton@epoc.u-bordeaux1.fr ; Julien.Van-De-Loock@ensem.inpl-nancy.fr; b.castelle@epoc.u-bordeaux1.fr ; v.marieu@epoc.u-bordeaux1.fr ; a.sottolichio@epoc.u-bordeaux1.fr ; g.detandt@epoc.u-bordeaux1.fr ; g.oggian@epoc.u-bordeaux1.fr ; h.derriennic@epoc.u-bordeaux1.fr ; s.bujan@epoc.u-bordeaux1.fr ; m.tissier@epoc.u-bordeaux1.fr ; p.castaing@epoc.u-bordeaux1.fr ; fabrice.pradalier@wanadoo.fr ; rmarcel@centres-animation.asso.fr 2. Universite Bordeaux 1. Laboratoire TREFLE-ENSCBP. 16 avenue Pey-Berland, 33607 Pessac Cedex. France. lubin@enscpb.fr 3. School of Civil Engineering, The University of Queensland, Brisbane QLD 4072, Australie. h.chanson@uq.edu.au