The geology and geophysics of Kuiper Belt object (486958) Arrokoth

The Cold Classical Kuiper Belt, a class of small bodies in undisturbed orbits beyond Neptune, are primitive objects preserving information about Solar System formation. The New Horizons spacecraft flew past one of these objects, the 36 km long contact binary (486958) Arrokoth (2014 MU69), in January 2019. Images from the flyby show that Arrokoth has no detectable rings, and no satellites (larger than 180 meters diameter) within a radius of 8000 km, and has a lightly-cratered smooth surface with complex geological features, unlike those on previously visited Solar System bodies. The density of impact craters indicates the surface dates from the formation of the Solar System. The two lobes of the contact binary have closely aligned poles and equators, constraining their accretion mechanism

A História da Alimentação: balizas historiográficas

Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at √s = 13 TeV with the ATLAS detector

A combination of searches for new heavy spin-1 resonances decaying into diferent pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at √s = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, tt¯, and tb) or third-generation leptons (τν and τ τ ) are included in this kind of combination for the frst time. A simplifed model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confdence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

Measurement of vector boson production cross sections and their ratios using pp collisions at √s = 13.6 TeV with the ATLAS detector

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Search for direct production of electroweakinos in final states with one lepton, jets and missing transverse momentum in pp collisions at √s = 13 TeV with the ATLAS detector

Searches for electroweak production of wino-like chargino pairs, χ˜ + 1 χ˜ − 1 , and of wino-like chargino and next-to-lightest neutralino, χ˜ ± 1 χ˜ 0 2 , are presented. The models explored assume that the charginos decay into a W boson and the lightest neutralino, χ˜ ± 1 → W±χ˜ 0 1 . The next-to-lightest neutralinos are degenerate in mass with the chargino and decay to χ˜ 0 1 and either a Z or a Higgs boson, χ˜ 0 2 → Zχ˜ 0 1 or hχ˜ 0 1 . The searches exploit the presence of a single isolated lepton and missing transverse momentum from the W boson decay products and the lightest neutralinos, and the presence of jets from hadronically decaying Z or W bosons or from the Higgs boson decaying into a pair of b-quarks. The searches use 139 fb−1 of √ s = 13 TeV proton-proton collisions data collected by the ATLAS detector at the Large Hadron Collider between 2015 and 2018. No deviations from the Standard Model expectations are found, and 95% confdence level exclusion limits are set. Chargino masses ranging from 260 to 520 GeV are excluded for a massless χ˜ 0 1 in chargino pair production models. Degenerate chargino and next-to-lightest neutralino masses ranging from 260 to 420 GeV are excluded for a massless χ˜ 0 1 for χ˜ 0 2 → Zχ˜ 0 1 . For decays through an on-shell Higgs boson and for mass-splitting between χ˜ ± 1 /χ˜ 0 2 and χ˜ 0 1 as small as the Higgs boson mass, mass limits are improved by up to 40 GeV in the range of 200–260 GeV and 280–470 GeV compared to previous ATLAS constraints

Measurement of the tt¯ cross section and its ratio to the Z production cross section using pp collisions at √s = 13.6 TeV with the ATLAS detector

The inclusive top-quark-pair production cross section σtt¯ and its ratio to the Z-boson production cross section have been measured in proton–proton collisions at √s = 13.6 TeV, using 29 fb−1 of data collected in 2022 with the ATLAS experiment at the Large Hadron Collider. Using events with an opposite-charge electron-muon pair and b-tagged jets, and assuming Standard Model decays, the top-quark-pair production cross section is measured to be σtt¯=850±3(stat.)±18(syst.)±20(lumi.) pb. The ratio of the tt¯ and the Z-boson production cross sections is also measured, where the Z-boson contribution is determined for inclusive e+e− and μ+μ− events in a fiducial phase space. The relative uncertainty on the ratio is reduced compared to the tt¯ cross section, thanks to the cancellation of several systematic uncertainties. The result for the ratio, Rtt¯/Z=1.145±0.003(stat.)±0.021(syst.)±0.002(lumi.) is consistent with the Standard Model prediction using the PDF4LHC21 PDF set

Spatial economics of biological control: investing in new releases of insects for earlier limitation of Paterson's curse in Australia

Paterson's curse and related weeds (Echiurn spp.) were introduced as garden flowers before 1850 and have spread to over 30 million ha in southern Australia. Four hundred successful releases of crown weevil (M. larvatus) populations specifically targeting Echiurn spp. were made in the 1993-2000 period. Based on the timing, location and performance of these past releases of beneficial insects, spatially and temporally specific trajectories of biocontrol have been simulated. Insect populations established by the past releases are expected to cover expanding areas at densities sufficient to limit host Echiurn infestations only over the next 25-50 years. The present analysis tackles the questions of where and how many additional releases are economically justified to speed up this process. We identify 31 districts in which diminishing niches for further insect releases are projected over time, according to the locations of damaging weed infestations and the timing, location and numbers of past insect releases. Benefits of biocontrol are expressed in terms of the value of recovered pasture productivity, keyed to estimates of loss and to historical district livestock inventories converted to dry sheep equivalent (DSE) feed availability levels to which prices are applied. Expected marginal contributions of increments of new releases were simulated for each of the 31 districts, subject to the space/time limitations of each niche. Our explicit accounting for the spatial and temporal dimensions has made possible the economically optimal targeting of new biocontrol releases. For example, at $12/DSE and a marginal cost of$2000 per release, with a discount rate of 10%, we find there is a case for a program of over 400 new releases targeted to 17 districts, with as few as five releases to each of several and as many as 70 releases in one district. Crown Copyright© 2002 Published by Elsevier Science B.V. All rights reserved

BENEFIT- COST ANALYSIS FOR BIOLOGICAL CONTROL OF ECHIUM WEED SPECIES (Paterson’s curse / Salvation Jane)

Based on the timing and location of 400 successful releases of insects specifically targeting Echium species of weeds including PatersonÕs curse / ÒSalvation JaneÓ since 1992 across southern Australia, and estimates of insect attack and spread rates according to dates of weed germination, a benefit / cost analysis is developed for the biological control research and development program begun by CSIRO in 1972. Australian meat and wool industries have also contributed funding to the program, in addition to in-kind contributions of the NSW, Victorian, South Australian and Western Australian state departments, and since 1995 the Weeds CRC. Total R&D expenditures by CSIRO and the partners mentioned above will reach $14 million by 2001. Annual benefits in terms of increased productivity of grazing lands are projected to rise from near-zero in 2000 to some$73 million by 2015, based on a value of $8/DSE. These sums do not include savings due to reduced spray costs as offsetting expenses will arise with management practices required to maximise the success of bio-control agents, and to limit reinvasion by other pasture weeds. The discounted (52015 is projected at$259 million, for a B/C ratio of 14:1 and an internal rate of return exceeding 17%. Because lower attack and spread rates of the insects are observed in regions with late autumn breaks, a slow build-up of benefits is expected to continue over many years. The discounted NPV for the 1972-2050 period is estimated to be $916 million, with a B/C ratio of 47:1 and an internal rate of return exceeding 19%

Electrical Manipulation of Magnetic Anisotropy in a Fe 81 Ga 19 / Pb ( Mg 1 / 3 Nb 2 / 3 ) O 3 - Pb ( Zr x Ti 1 − x ) O 3 Magnetoelectric Multiferroic Composite

International audienc

Thickness dependence of magnetization reversal and magnetostriction in Fe 81 Ga 19 thin films

International audienc