48 research outputs found
Sex-specific patterns of minimal compensation of care during and after short term mate removal in biparental blue tits
Early theoretical models predicted that over evolutionary timescales, changes in effort by one biparental parent should result in incomplete compensation by the other. Empirical studies, however, report responses ranging from no compensation through to complete compensation which may mean that parents respond to each other's efforts over short time scales, as predicted by some recent theoretical models. Few studies have examined behavioural changes over short time periods which mimic the onset of reduced effort so we removed one blue tit (Cyanistes caeruleus) parent for 20 min during nestling provisioning. We then quantified the provisioning rates of both parents for 60 min âpre-removalâ, the non-removed partner during the 20 min âremovalâ period and both parents for 60 min âpost-removalâ. When compared to pre-removal, both sexes reduced their provisioning rates during the removal stage and also during the post-removal stage. There were, however, sex-specific provisioning patterns in the hour after the parent was returned because after females were released, males began provisioning at a relatively high rate and then maintained that rate across the hour after removal whereas after males were released, females began provisioning at a low rate but significantly increased thereafter. There was no long term effect on offspring fitness, which probably reflects the short time parents were removed and so we conclude that parents with biparental care adjust their provisioning rates to successfully overcome very short term decreases in care
Understanding behavioural responses to human-induced rapid environmental change: a meta-analysis
Behavioural responses are often the first reaction of an organism to human-induced rapid environmental change (HIREC), yet current empirical evidence provides no consensus about the main environmental features that animals respond to behaviourally or which behaviours are responsive to HIREC. To understand how changes in behaviour can be predicted by different forms of HIREC, we conducted a meta-analysis of the existing empirical literature focusing on behavioural responses to five axes of environmental change (climate change, changes in CO2, direct human impact, changes in nutrients and biotic exchanges) in five behavioural domains (aggression, exploration, activity, boldness and sociability) across a range of taxa but with a focus on fish and bird species. Our meta-analysis revealed a general absence of directional behavioural responses to HIREC. However, the absolute magnitude of the effect sizes was large. This means that animals have strong behavioural responses to HIREC, but the responses are not clearly in any particular direction. Moreover, the absolute magnitude of the effect sizes differed between different behaviours and different forms of HIREC: Exploration responded more strongly than activity, and climate change induced the strongest behavioural responses. Model heterogeneities identified that effect sizes varied primarily because of study design, and the specific sample of individuals used in a study; phylogeny also explains significant variation in our bird model. Based on these results, we make four recommendations to further our understanding: 1) a more balanced representation of laboratory and field studies, 2) consideration of context dependency, 3) standardisation of the methods and definitions used to quantify and study behaviours and 4) consideration of the role for individual differences in behaviour. Š 2021 Nordic Society Oikos. Published by John Wiley & Sons LtdPeer reviewe
Correlated evolution of nest and egg characteristics in birds
Correlational selection is defined as selection for adaptive character combinations, and it therefore favours combinations of coevolved traits via phenotypic integration. Whereas the evolution of avian nest-building and egg-laying characteristics are well understood, their correlated dynamics remain overlooked. Here, we examined patterns of correlated evolution between nest, egg and clutch characteristics in 855 species of birds from 90 families, representing nearly 9% and 33% of avian species- and family-level diversity. We show that the ancestral state of birdsâ nests was semi-open with nest sites having since become progressively more open over time. Furthermore, nest characteristics appear to have influenced egg-laying patterns in that while semi-open nests with variable clutch sizes were probably ancestral, clutch sizes have declined over evolutionary time in both open and closed nests. Ancestrally, avian eggs were also large, heavy and either elliptic or round, and there have been high transition rates from elliptic to round eggs in open nests and vice versa in closed nests. Ancestrally, both unpigmented (white) and pigmented (blueâbrown) eggs were laid in open nests, although blueâbrown eggs have transitioned more to white over time in open and closed nests, independently. We conclude that there has been a remarkable level of correlated evolution between the nest and egg characteristics of birds, which supports scenarios of correlational selection on both of these extended avian phenotypes
The evolution of nest site use and nest architecture in modern birds and their ancestors
The evolution of nest site use and nest architecture in the non-avian ancestors of birds remains poorly understood because nest structures do not preserve well as fossils. Nevertheless, the evidence suggests that the earliest dinosaurs probably buried eggs below ground and covered them with soil so that heat from the substrate fuelled embryo development, while some later dinosaurs laid partially exposed clutches where adults incubated them and protected them from predators and parasites. The nests of euornithine birdsâthe precursors to modern birdsâwere probably partially open and the neornithine birdsâor modern birdsâwere probably the first to build fully exposed nests. The shift towards smaller, open cup nests has been accompanied by shifts in reproductive traits, with female birds having one functioning ovary in contrast to the two ovaries of crocodilians and many non-avian dinosaurs. The evolutionary trend among extant birds and their ancestors has been toward the evolution of greater cognitive abilities to construct in a wider diversity of sites and providing more care for significantly fewer, increasingly altricial, offspring. The highly derived passerines reflect this pattern with many species building small, architecturally complex nests in open sites and investing significant care into altricial young. This article is part of the theme issue âThe evolutionary ecology of nests: a cross-taxon approachâ
Spectrum of pheochromocytoma in the 131 I-MIBG era
131 I-metaiodobenzylguanidine ( 131 I-MIBG) scintigraphy allows for both functional diagnosis and anatomical localization of pheochromocytoma. The spectrum of pheochromocytoma since the routine use of preoperative 131 I-MIBG scan was studied. From 1980 to 1986, a total of 34 patients were primarily diagnosed and treated at the University of Michigan Medical Center, Ann Arbor, Michigan, U.S.A. There were 16 males and 18 females. The mean age was 38 years and 4 patients (11.8%) were under 18 years of age. Six patients (17.6%) had family history of pheochromocytoma or multiple endocrine neoplasia (MEN) II syndrome. The presenting symptoms were hypertension in 29 patients (85.3%); attacks of headache, palpitation, sweating, and flushing in 4 (11.8%), and 1 patient presented with a neck mass. Plasma catecholamines were elevated in 97% of patients while urinary catecholamines and metabolites were elevated in 93.5%. 131 I-MIBG was accurate in 82.3%, partly positive in 11.8%, and false-negative in 5.9% of patients. CT scan was accurate in 80%, partly positive in 10%, but failed to show the tumor in another 10% of patients. At operation, extraadrenal lesions were found in 38.2% of the patients and among these, one-third were extraabdominal. Multiple tumors occurred in 5 (14.7%), and bilateral adrenal lesions occurred in 4 patients (11.8%). Malignancy was diagnosed in 3 patients (8.8%) after an average follow-up period of 2 years. We conclude that the use of routine preoperative 131 I-MIBG scanning improves localization of pheochromocytoma and earlier diagnosis is possible in patients with MEN II syndrome. Multiple tumors, extraadrenal and extraabdominal lesions occur more often than commonly believed. The low rate of confirmed malignancy is probably related to the short period of follow-up. La scintigraphie Ă l' 131 I-MIBG permet de diagnostiquer et de localiser les phĂŠochromocytomes. Toute la gamme de types de phĂŠochromocytomes reconnu depuis l'utilisation prĂŠopĂŠratoire systĂŠmatique de la scintigraphie Ă l' 131 I-MIBG est prĂŠsentĂŠe. Entre 1980 et 1986, 34 patients ont ĂŠtĂŠ explorĂŠs et traitĂŠs au Centre MĂŠdical de l'UniversitĂŠ de Michigan, Ann Arbor, Michigan. Il y avait 16 hommes et 18 femmes. L'âge moyen ĂŠtait de 38 ans, et 4 patients (11.8%) avaient moins de 18 ans. Six patients (17.6%) avaient des antĂŠcĂŠdents familiaux de phĂŠochromocytome ou de nĂŠoplasmes endocrines multiples (MEN) du type II. Les symptĂ´mes amenant Ă consulter ĂŠtaient l'hypertension chez 29 patients (85.3%), des crises de cĂŠphalĂŠes, des palpitations et un flush chez 4 patients (11.8%); un patient prĂŠsentait une masse cervicale. Les catĂŠcholamines plasmatiques ĂŠtaient ĂŠlevĂŠes chez 97% des patients alors que les catĂŠcholamines et leurs mĂŠtabolites ĂŠtaient en quantitĂŠ ĂŠlevĂŠe chez 93.5% des patients. La scintigraphie Ă l' 131 I-MIBG ĂŠtait positive chez 82.3%, partiellement positive chez 11.8%, et faussement nĂŠgative chez 5.9% des patients. La tomodensitomĂŠtrie ĂŠtait positive chez 80%, partiellement positive chez 10%, et faussement nĂŠgative chez 10% des patients. A l'intervention, des lĂŠsions extra-surrĂŠnales ĂŠtaient prĂŠsentes dans 38.2% des cas, et parmi celles-ci, un tiers ĂŠtaient extra-abdominales. Les tumeurs ĂŠtaient multiples dans 5 cas (14.7%), et bilatĂŠrales surrĂŠnales dans 4 cas (11.8%). Une tumeur maligne ĂŠtait diagnostiquĂŠe chez 3 patients (8.8%), après une pĂŠriode de suivi de 2 ans en moyenne. Nous concluons que l'utilisation systĂŠmatique de la scintigraphie Ă l' 131 I-MIBG amĂŠliore la localisation des phĂŠochromocytomes, permettant un diagnostic plus prĂŠcoce chez les patients prĂŠsentant un syndrome MEN II. La multiplicitĂŠ tumorale et les localisations extra-mĂŠdullosurrĂŠnales ou extra-abdominales se voient beaucoup plus frĂŠquemment qu'on le pensait auparavant. Le taux de malignitĂŠ peu ĂŠlevĂŠ ĂŠtait probablement en rapport avec la courte pĂŠriode de suivi. La escintigrafĂa con 131 I-MIBG permite tanto la localizaciĂłn anatĂłmica como el diagnĂłstico funcional del feocromocitoma. Las caracterĂsticas o espectro del feocromocitoma a partir del uso rutinario de 131 I-MIBG han sido estudiadas.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41282/1/268_2005_Article_BF01655447.pd
Connecting the data landscape of long-term ecological studies: The SPI-Birds data hub
The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-term studies of birds, we have created the SPI-Birds Network and Database (www.spibirds.org)\u2014a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI-Birds has recruited over 120 members, and currently hosts data on almost 1.5 million individual birds collected in 80 populations over 2,000 cumulative years, and counting. SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by the principles of Findable, Accessible, Interoperable and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language). The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such as ours, COMADRE for animal demography, etc.) will aid much-needed large-scale ecological data integration
Nucleosomes in gene regulation: theoretical approaches
This work reviews current theoretical approaches of biophysics and
bioinformatics for the description of nucleosome arrangements in chromatin and
transcription factor binding to nucleosomal organized DNA. The role of
nucleosomes in gene regulation is discussed from molecular-mechanistic and
biological point of view. In addition to classical problems of this field,
actual questions of epigenetic regulation are discussed. The authors selected
for discussion what seem to be the most interesting concepts and hypotheses.
Mathematical approaches are described in a simplified language to attract
attention to the most important directions of this field
Search for a W ' boson decaying to a muon and a neutrino in pp collisions at âs =7 TeV
This is the Pre-Print version of the Article. The official published version can be accessed from the link below - Copyright @ 2011 ElsevierA new heavy gauge boson, W', decaying to a muon and a neutrino, is searched for in pp collisions at a centre-of-mass of 7 TeV. The data, collected with the CMS detector at the LHC, correspond to an integrated luminosity of 36 inverse picobarns. No significant excess of events above the standard model expectation is found in the transverse mass distribution of the muon-neutrino system. Masses below 1.40 TeV are excluded at the 95% confidence level for a sequential standard-model-like W'. The W' mass lower limit increases to 1.58 TeV when the present analysis is combined with the CMS result for the electron channel.This work is supported by the FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences
and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3
(France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR
(Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)
First measurement of hadronic event shapes in pp collisions at âs = 7 TeV
This is the Pre-Print version of the Article - Copyright @ 2011 ElsevierHadronic event shapes have been measured in proton-proton collisions at sqrt(s)=7 TeV, with a data sample collected with the CMS detector at the LHC. The sample corresponds to an integrated luminosity of 3.2 inverse picobarns. Event-shape distributions, corrected for detector response, are compared with five models of QCD multijet production
Search for microscopic black hole signatures at the Large Hadron Collider
This is the Pre-Print version of the Article. The official published paper can be accessed from the link below - Copyright @ 2011 ElsevierA search for microscopic black hole production and decay in pp collisions at a center-of-mass energy of 7 TeV has been conducted by the CMS Collaboration at the LHC, using a data sample corresponding to an integrated luminosity of 35 inverse picobarns. Events with large total transverse energy are analyzed for the presence of multiple high-energy jets, leptons, and photons, typical of a signal expected from a microscopic black hole. Good agreement with the expected standard model backgrounds, dominated by QCD multijet production, is observed for various final-state multiplicities. Limits on the minimum black hole mass are set, in the range 3.5 -- 4.5 TeV, for a variety of parameters in a model with large extra dimensions, along with model-independent limits on new physics in these final states. These are the first direct limits on black hole production at a particle accelerator.This work is supported by the FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of
Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and
CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH
(Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU
(Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC
(Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss
Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)