367 research outputs found
Intra-sexual competition alters the relationship between testosterone and ornament expression in a wild territorial bird
Open Access funded by Natural Environment Research Council Under a Creative Commons licensePeer reviewedPublisher PD
Urban agriculture: a global analysis of the space constraint to meet urban vegetable demand
Urban agriculture (UA) has been drawing a lot of attention recently for several reasons: the majority of the world population has shifted from living in rural to urban areas; the environmental impact of agriculture is a matter of rising concern; and food insecurity, especially the accessibility of food, remains a major challenge. UA has often been proposed as a solution to some of these issues, for example by producing food in places where population density is highest, reducing transportation costs, connecting people directly to food systems and using urban areas efficiently. However, to date no study has examined how much food could actually be produced in urban areas at the global scale. Here we use a simple approach, based on different global-scale datasets, to assess to what extent UA is constrained by the existing amount of urban space. Our results suggest that UA would require roughly one third of the total global urban area to meet the global vegetable consumption of urban dwellers. This estimate does not consider how much urban area may actually be suitable and available for UA, which likely varies substantially around the world and according to the type of UA performed. Further, this global average value masks variations of more than two orders of magnitude among individual countries. The variations in the space required across countries derive mostly from variations in urban population density, and much less from variations in yields or per capita consumption. Overall, the space required is regrettably the highest where UA is most needed, i.e., in more food insecure countries. We also show that smaller urban clusters (i.e., <100 km2 each) together represent about two thirds of the global urban extent; thus UA discourse and policies should not focus on large cities exclusively, but should also target smaller urban areas that offer the greatest potential in terms of physical space
Avian predators as a biological control system of common vole (Microtus arvalis) populations in NW Spain: experimental set-up and preliminary results
Jareño, D., Paz, A., Arroyo, L., Viñuela, J., Arroyo, B.E., Mougeot, F., Luque-Larena, J.J., Fargallo, J.A
Structure of unbound neutron-rich He studied using single-neutron transfer
The 8He(d,p) reaction was studied in inverse kinematics at 15.4A MeV using
the MUST2 Si-CsI array in order to shed light on the level structure of 9He.
The well known 16O(d,p)17O reaction, performed here in reverse kinematics, was
used as a test to validate the experimental methods. The 9He missing mass
spectrum was deduced from the kinetic energies and emission angles of the
recoiling protons. Several structures were observed above the neutron-emission
threshold and the angular distributions were used to deduce the multipolarity
of the transitions. This work confirms that the ground state of 9He is located
very close to the neutron threshold of 8He and supports the occurrence of
parity inversion in 9He.Comment: Exp\'erience GANIL/SPIRAL1/MUST
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Schantz et al., 1999) . Carotenoids can scavenge free radicals and cytotoxic molecules produced during immune respons
Identification of genes responding to nematode infection in red grouse.
Abstract The identification of genes involved in a host's response to parasite infection provides both a means for understanding the pathways involved in immune defence and a target for examining host-parasite co-evolution. Most studies rely on a candidate gene approach derived from model systems to identify gene targets of interest, and there have been a dearth of studies geared towards providing a holistic overview of immune response from natural populations. We carried out an experiment in a natural population of red grouse (Lagopus lagopus scoticus) to manipulate levels of Trichostrongylus tenuis parasite infection. The transcriptomic response of individuals was examined from standard cDNA and suppressive subtractive hybridization (SSH) libraries produced from gut, liver and spleen, enriching for genes expressed in response to T. tenuis infection. A total of 2209 and 3716 unique transcript sequences were identified from the cDNA and SSH libraries, respectively. Forty-five of these had Gene Ontology annotation associated with immune response. Some of these genes have previously been reported from laboratory-based studies of model species as important in immune response to gastrointestinal parasite infection; however, multiple novel genes were also identified. These may reveal novel pathways involved in the host response of grouse to T. tenuis and provide a resource that can be utilized as candidate genes in other species
Isomeric excitation energy for In from mass spectrometry reveals constant trend next to doubly magic Sn
The excitation energy of the 1/2 isomer in In at is
measured to be 671(37) keV and the mass uncertainty of the 9/2 ground state
is significantly reduced using the ISOLTRAP mass spectrometer at ISOLDE/CERN.
The measurements exploit a major improvement in the resolution of the
multi-reflection time-of-flight mass spectrometer. The results reveal an
intriguing constancy of the isomer excitation energies in
neutron-deficient indium that persists down to the shell closure, even
when all neutrons are removed from the valence shell. This trend is used to
test large-scale shell model, \textit{ab initio}, and density functional theory
calculations. The models have difficulties describing both the isomer
excitation energies and ground-state electromagnetic moments along the indium
chain.Comment: 13 pages, 4 figure
Nuclear structure and reaction studies at SPIRAL
The SPIRAL facility at GANIL, operational since 2001, is described briefly.
The diverse physics program using the re-accelerated (1.2 to 25 MeV/u) beams
ranging from He to Kr and the instrumentation specially developed for their
exploitation are presented. Results of these studies, using both direct and
compound processes, addressing various questions related to the existence of
exotic states of nuclear matter, evolution of new "magic numbers", tunnelling
of exotic nuclei, neutron correlations, exotic pathways in astrophysical sites
and characterization of the continuum are discussed. The future prospects for
the facility and the path towards SPIRAL2, a next generation ISOL facility, are
also briefly presented.Comment: 48 pages, 27 figures. Accepted for publication in Journal of Physics
Methodology for the development of a national Dental Practice-Based Research Network survey on dentistâs beliefs and behaviors concerning antibiotic prophylaxis
Background
Dentists are high prescribers of antibiotics for both treatment and prevention of infection, although there are few guidelines to aid clinicians. Given the worldwide concerns about unnecessary use of antibiotics, there is a need for a better understanding of dentistsâ use of these drugs for antibiotic prophylaxis (AP) to prevent distant site infections (i.e., infective endocarditis and prosthetic joint infection).
Objective
The aim of this study was to develop and implement an effective, self-reporting, cross-sectional, survey instrument that optimized the response rate and maximized reliability and validity for determining the beliefs and behaviors of a large and nationally representative group of generalist and specialist dentists concerning their use of AP.
Study Design
A 15-question survey (58 items) was developed in a structured process by a multidisciplinary team and configured for automated online dissemination to 3584 national Dental Practice-Based Research Network (DPBRN; hitherto referred to as âNetworkâ) practitioners. The implementation phase consisted of 3 waves of greater than 1000 Network members. Additionally, 47 randomly selected dentists were surveyed twice to assess testâretest reliability.
Results
Of 3584 eligible Network members, 2169 (60.5%) completed the survey. The age and geographic distributions of responders was similar to those of dentists in the 2019 American Dental Association census. Furthermore, testâretest weighted kappa values for the survey were acceptable (median 0.56; interquartile range 0.42â0.64).
Conclusions
We developed a highly structured survey with a high response rate and good reliability that will allow us to obtain unique data on dentistsâ beliefs and practices regarding AP prescribing
First Glimpse of the N= 82 Shell Closure below Z= 50 from Masses of Neutron-Rich Cadmium Isotopes and Isomers
We probe the N = 82 nuclear shell closure by mass measurements of neutron-rich cadmium isotopes with the ISOLTRAP spectrometer at ISOLDE-CERN. The new mass of 132 Cd offers the first value of the N = 82 , two-neutron shell gap below Z = 50 and confirms the phenomenon of mutually enhanced magicity at 132 Sn . Using the recently implemented phase-imaging ion-cyclotron-resonance method, the ordering of the low-lying isomers in 129 Cd and their energies are determined. The new experimental findings are used to test large-scale shell-model, mean-field, and beyond-mean-field calculations, as well as the ab initio valence-space in-medium similarity renormalization group
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