654 research outputs found

    Increased food provisioning by female Montagu's Harriers in years with food shortage weakens sex-specific roles in parental care

    Get PDF
    n many owl and raptor species, sexes have distinct parental roles. Females incubate the eggs and raise the chicks until independence, while males provide females and their chicks with food. This is believed to reduce sexual conflict over parental care as tasks do not overlap. The level of parental care is also shaped by parent-offspring conflict. The scarcity of empirical data on parental investment in species with sex-specific parental roles was our motivation to study parental care in the Montagu’s Harrier Circus pygargus in relation to natural annual variation in food availability (vole abundance). By tracking individual birds using GPS-trackers, several aspects of parental care (the number of food provisioning trips, home range size and nest attendance) could be quantified for different nesting phases. We found that in food-poor years, males spent less time near the nest, and had lower food provisioning rates during the incubation and nestling phases. In addition, males had larger home ranges in food-poor years, a possible indicator of increased foraging effort. In contrast, females increased their contribution to food provisioning in food-poor years, as shown by higher food provisioning rates and larger home ranges. This increased foraging effort came at the cost of lower nest attendance by females. Our data suggest that, when food abundance declines, Montagu’s Harriers shift from a system with almost strict sex-specific parental roles towards a system where both parents provide the same type of care with possibly increased sexual conflict

    Increased food provisioning by female Montagu's Harriers in years with food shortage weakens sex-specific roles in parental care

    Get PDF
    n many owl and raptor species, sexes have distinct parental roles. Females incubate the eggs and raise the chicks until independence, while males provide females and their chicks with food. This is believed to reduce sexual conflict over parental care as tasks do not overlap. The level of parental care is also shaped by parent-offspring conflict. The scarcity of empirical data on parental investment in species with sex-specific parental roles was our motivation to study parental care in the Montagu’s Harrier Circus pygargus in relation to natural annual variation in food availability (vole abundance). By tracking individual birds using GPS-trackers, several aspects of parental care (the number of food provisioning trips, home range size and nest attendance) could be quantified for different nesting phases. We found that in food-poor years, males spent less time near the nest, and had lower food provisioning rates during the incubation and nestling phases. In addition, males had larger home ranges in food-poor years, a possible indicator of increased foraging effort. In contrast, females increased their contribution to food provisioning in food-poor years, as shown by higher food provisioning rates and larger home ranges. This increased foraging effort came at the cost of lower nest attendance by females. Our data suggest that, when food abundance declines, Montagu’s Harriers shift from a system with almost strict sex-specific parental roles towards a system where both parents provide the same type of care with possibly increased sexual conflict

    A multi-reflection time-of-flight mass spectrometer for the offline ion source of the PUMA experiment

    Full text link
    The antiProton Unstable Matter Annihilation experiment (PUMA) at CERN aims at investigating the nucleon composition in the matter density tail of radioactive as well as stable isotopes by use of low-energy antiproton-nucleon annihilation processes. For this purpose, antiprotons provided by the Extra Low ENergy Antiproton (ELENA) facility will be trapped together with the ions of interest. While exotic ions will be obtained by the Isotope mass Separator On-Line DEvice (ISOLDE), stable ions will be delivered from an offline ion source setup designed for this purpose. This allows the proposed technique to be applied to a variety of stable nuclei and for reference measurements. For beam purification, the ion source setup includes a multi-reflection time-of-flight mass spectrometer (MR-ToF MS). Supported by SIMION simulations, an earlier MR-ToF MS design has been modified to meet the requirements of PUMA. During commissioning of the new MR-ToF device with Ar+^+ ions, mass resolving powers in excess of 50,000 have been obtained after 150 revolutions, limited by the chopping of the continuous beam from an electron impact ionisation source

    FĂ©lix Candela. En memoria (1910-1997). Del cascarĂłn de hormigĂłn a las estructuras ligeras del s. XXI

    Get PDF
    January 27th of this year, 2010, was the centenary of the birth of a famous architect of Spanish origin, FĂ©lix Candela, one of the most prominent players in modern architecture’s thin shell adventure. His international fame was based on precisely that, the construction of over 800 thin concrete shells characterized not only by their rationality and optimal strength, but also by their striking sculptural beauty. Architects such as Frei Otto, Ove Arup and David Billington justifiably called his work“structural art”. In addition analyzing FĂ©lix Candela’s contribution to modern architecture, the present article explores new lightweight structures as the ongoing pursuit of the optimization of structural form with different materials and technologies. That pursuit, both past and present, constitutes the focus of attention of the International Association for Structural Shells, IASS, founded by Eduardo Torroja in 1959 and fully operational today.El 27 de enero de 2010 se cumpliĂł el centenario del nacimiento de cĂ©lebre arquitecto de origen español FĂ©lix Candela, uno de los mĂĄs destacados protagonistas de la Aventura Laminar de la Arquitectura Moderna. Su fama internacional la adquiriĂł a travĂ©s de la construcciĂłn de mĂĄs de 800 cascarones de hormigĂłn armado dotados, no sĂłlo de una racional y Ăłptima forma resistente, sino tambiĂ©n de una impactante y escultural belleza. No en vano, Frei Otto, Ove Arup y David Billington han descrito su obra como un “Arte Estructural”. Al hilo del anĂĄlisis de las aportaciones realizadas por FĂ©lix Candela, el presente artĂ­culo analiza tambiĂ©n nuevas estructuras ligeras, como continuidad histĂłrica de esa racional bĂșsqueda de la optimizaciĂłn de la forma resistente con diferentes materiales y tecnologĂ­as. EvoluciĂłn y destino contemplado por la Internacional Association for Structural Shells IASS, fundada por Eduardo Torroja en 1959 y que hoy continĂșa en plena actividad

    Self-recovering stimuli-responsive macrocycle-equipped supramolecular ionogels with unusual mechanical properties

    Get PDF
    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugĂ€nglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.A chiral, crown-ether-functionalized bisurea gelator forms supramolecular gels in ionic liquids. The resulting ionogels show a remarkably high thermal stability with gel–sol transition temperatures (Tgs) reaching more than 100 °C. The mechanical strength of these ionogels is surprisingly high and even comparable to that of cross-linked protein fibres. Furthermore, the ionogels exhibit rapid self-recovery properties after structural damage caused by deformation. Pseudorotaxanes form from the gelators’ benzo[21]crown-7 ethers as the wheels and secondary ammonium ions as the axles despite the competition between that cation and the imidazolium ions of the ionic liquid for crown ether binding. Pseudorotaxane formation as an external chemical stimulus triggers the gel–sol transition of the ionogels.DFG, SFB 765, Multivalenz als chemisches Organisations- und Wirkprinzip: Neue Architekturen, Funktionen und Anwendunge

    Wisdom of the crowd: insights gained from comparing predicted and observed effects of blood pressure lowering strategies

    Get PDF
    In a first of its kind assessment in cardiovascular research, we assessed whether pooled cardiovascular expertise could accurately predict efficacy and tolerability for both a novel and an established treatment option. A survey was administered prior to the publication of the QUARTET (A Quadruple UltrA-low-dose tReatment for hypErTension) trial. QUARTET was a multicentre, double-blind, parallel-group, trial that randomised participants to initial treatment with either monotherapy or an ultra-low dose quadruple single pill combination for 12 weeks. Survey participants were asked to predict blood pressure (BP) at 12 weeks and 52 weeks for both groups

    Design of floor structures for human induced vibrations

    Get PDF
    In recent years, the introduction of new structural materials and innovative construction processes, associated to architectural and space arrangement requirements, in multi-storey buildings construction have produced significantly more flexible floor structural systems. The design of these floor systems is usually controlled by serviceability criteria, deflections or vibrations. Recognizing a gap in the design codes, this report gives a procedure for the determination and assessment of floor response for human induced vibrations. First, the proposed procedure is presented, giving particular attention to the human induced loading characterization, dynamic properties and the comfort criteria for the verification of floor structural systems. Design charts are derived. Finally, it is presented a guidance manual to use the simplified procedure proposed for the design of building floors for human induced vibrations. Two worked examples of the proposed design procedure are given, namely a filigree slab with ACB-composite beams and a composite slab with steel beams.JRC.DG.G.5-European laboratory for structural assessmen

    Ultra-low-dose quadruple combination blood pressure lowering therapy in patients with hypertension: The QUARTET randomized controlled trial protocol.

    Full text link
    High blood pressure is the leading cause of preventable morbidity and mortality globally. Many patients remain on single-drug treatment with poor control although guidelines recognize that most require combination therapy for blood pressure control. Our hypothesis is that a single-pill combination of four blood pressure- lowering agents each at a quarter dose may provide a simple, safe and effective blood pressure lowering solution which may also improve long term-adherence. The QUARTET (Quadruple UltrA-low-dose tReaTment for hypErTension) double-blind, active controlled, randomized clinical trial will examine whether ultra-low-dose quadruple combination therapy is more effective than guideline recommended standard care, in lowering blood pressure. QUARTET will enroll 650 participants with high blood pressure, either on no treatment or on monotherapy. Participants will be randomized 1:1 and allocated to intervention therapy of a single pill (quadpill) containing irbesartan 37.5 mg, amlodipine 1.25 mg, indapamide 0.625 mg and bisoprolol 2.5 mg or to control therapy of a single identical appearing pill containing irbesartan 150 mg. In both arms step up therapy of open-label amlodipine 5mg will be provided if BP is >140/90 at 6weeks. The primary outcome is the difference between groups in the change from baseline in mean unattended automated office systolic blood pressure at 12weeks follow-up. The primary outcome and some secondary outcomes will be assessed at 12weeks, there is an optional 12months extension phase to assess longer term efficacy and tolerability. Our secondary aims are to assess if this approach is safe, has fewer adverse effects and better tolerability compared to standard care control. QUARTET will therefore provide evidence for the effectiveness and safety of a new paradigm in the management of high blood pressure

    Occupational health legislation and practices related to seafarers on passenger ships focused on communicable diseases: results from a European cross-sectional study (EU SHIPSAN PROJECT)

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Seafarers play an important role in the transmission of communicable diseases. The aim of the present study is to draw information and identify possible gaps on occupational health practices related to seafarers sailing on ships within the European Union Member States (EU MS) with focus on communicable diseases.</p> <p>Methods</p> <p>A structured questionnaire was sent to competent authorities from 21 EU MS. The questionnaire included questions about occupational health policies, medical certification of seafarers, communicable diseases reporting and relevant legislation. Descriptive analysis of the data was conducted by the use of Epi Info software: EU MS were categorized in four priority groups (A, B, C, D) based on: number of passenger ships visits, volume of passengers, and number of ports in each country. Moreover, EU MS were categorized to old and new, based on the date of entry in the EU.</p> <p>Results</p> <p>All 21 countries with relevant competent authorities responded to the questionnaire. The existence of specific national legislation/regulation/guidelines related to vaccination of seafarers was reported by three out of the 21 (14%) responding authorities. Surveillance data of communicable diseases related to seafarers are collected and analyzed by 4 (19%) authorities. Five out of 21 of the responding countries (24%) reported that tuberculin test result is required for the issuance of seafarer's medical certificate while a great variety of medical examination is required for the issuance of this certificate among countries.</p> <p>Gaps on occupational health services focused on communicable diseases related to maritime occupation have been reported by 33% of the responding countries.</p> <p>Responding authorities from Group A and B had the highest percentage of reported gaps followed by groups C and D. Old MS reported a higher frequency regarding gaps on occupational health services in comparison to new MS.</p> <p>Conclusion</p> <p>Our results revealed heterogeneity regarding occupational health of maritime employees in EU MS. This work provides some evidence that further work at international and European level could be considered, in order to explore the potential for harmonized initiatives regarding occupational health of seafarers.</p
    • 

    corecore