The Dust Trail of Comet 67P/Churyumov-Gerasimenko between 2004 and 2006

We report on observations of the dust trail of comet 67P/Churyumov-Gerasimenko (CG) in visible light with the Wide Field Imager at the ESO/MPG 2.2m telescope at 4.7 AU before aphelion, and at 24 micron with the MIPS instrument on board the Spitzer Space Telescope at 5.7 AU both before and after aphelion. The comet did not appear to be active during our observations. Our images probe large dust grains emitted from the comet that have a radiation pressure parameter beta<0.01. We compare our observations with simulated images generated with a dynamical model of the cometary dust and constrain the emission speeds, size distribution, production rate and geometric albedo of the dust. We achieve the best fit to our data with a differential size distribution exponent of -4.1, and emission speeds for a beta=0.01 particle of 25 m/s at perihelion and 2 m/s at 3 AU. The dust production rate in our model is on the order of 1000 kg/s at perihelion and 1 kg/s at 3 AU, and we require a dust geometric albedo between 0.022 and 0.044. The production rates of large (>10 micron) particles required to reproduce the brightness of the trail are sufficient to also account for the coma brightness observed while the comet was inside 3 AU, and we infer that the cross-section in the coma of CG may be dominated by grains of the order of 60-600 micron.Comment: 79 pages, 13 figures, 6 tables. Accepted for publication in Icaru

miR-146a is a significant brake on autoimmunity, myeloproliferation, and cancer in mice

Excessive or inappropriate activation of the immune system can be deleterious to the organism, warranting multiple molecular mechanisms to control and properly terminate immune responses. MicroRNAs (miRNAs), ~22-nt-long noncoding RNAs, have recently emerged as key posttranscriptional regulators, controlling diverse biological processes, including responses to non-self. In this study, we examine the biological role of miR-146a using genetically engineered mice and show that targeted deletion of this gene, whose expression is strongly up-regulated after immune cell maturation and/or activation, results in several immune defects. Collectively, our findings suggest that miR-146a plays a key role as a molecular brake on inflammation, myeloid cell proliferation, and oncogenic transformation

Assessing land use effects on ecohydrological partitioning in the critical zone through isotope‐aided modelling

Stable water isotopes are naturally occurring conservative tracers that can ‘fingerprint’ water sources and track ecohydrological fluxes across the critical zone (CZ). Parsimonious, tracer-aided models allow effective quantification of the ecohydrological partitioning of rainfall into different water fluxes. We incorporated stable water isotopes into a one-dimensional, tracer-aided model (EcoIsoPlot) to follow the pathway of precipitation through the CZ at a lowland catchment—the long-term experimental Demnitzer Millcreek Catchment (DMC), Germany—with contrasting vegetation covers (forest, agroforestry, grassland and arable). Precipitation (amount and δ2H), potential evapotranspiration (PET), leaf area index (LAI), air temperature and relative humidity were used as input data for modelling the growing season of 2021. The year had relatively average overall wetness, but a dry, cold spring with snowfall, and an exceptionally large summer storm event (~60 mm precipitation). Multi-criteria calibration of the model was conducted using depth-specific soil moisture and soil water δ2H measurements as targets. The novel incorporation of isotopes into model calibration constrained process representation of the estimated water balance with reasonable simulations and uncertainty bounds for water partitioning. Throughout the soil profile, soil moisture dynamics and stable water isotope variations were captured reasonably well. Green water fluxes (evapotranspiration) were highest at the forest site and blue water fluxes (groundwater recharge) highest at the grassland. Comparing simulations with estimated potential evapotranspiration (ET) and measured groundwater table fluctuations added further confidence to the modelling result. Overall, these may suggest a slight underestimation of ET and slight overestimation of recharge, though the results are similar to previous findings. Our study demonstrated the potential of stable water isotope data to enhance relatively simple, transferrable approaches to ecohydrological modelling of water fluxes in the CZ and to help improve model consistency. Such low-parameterised tracer-aided models have major potential for evidence-based applications to aid management and help stakeholder communication.Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347Leibniz Association http://dx.doi.org/10.13039/501100001664Einstein Foundation Berlin http://dx.doi.org/10.13039/501100006188Einstein Stiftung Berlin http://dx.doi.org/10.13039/501100006188Leverhulme Trust http://dx.doi.org/10.13039/501100000275Peer Reviewe

Assessing land use effects on ecohydrological partitioning in the critical zone through isotope-aided modelling

Research Funding Bundesministerium für Bildung und Forschung. Grant Numbers: 033W034A, 16LW0156 Leibniz Association Einstein Foundation Berlin Einstein Stiftung Berlin. Grant Number: ERU-2020- 609 Leverhulme Trust Article Funding Open Access funding enabled and organized by Projekt DEAL.Peer reviewedPublisher PD

Integrity of the circadian clock determines regularity of high-frequency and diurnal LFP rhythms within and between brain areas

Circadian clocks control most physiological processes of many species. We specifically wanted to investigate the influence of environmental and endogenous rhythms and their interplay on electrophysiological dynamics of neuronal populations. Therefore, we measured local field potential (LFP) time series in wild-type and Cryptochrome 1 and 2 deficient (Cry1/2−/−) mice in the suprachiasmatic nucleus and the nucleus accumbens under regular light conditions and constant darkness. Using refined descriptive and statistical analyses, we systematically profiled LFP time series activity. We show that both environmental and endogenous rhythms strongly influence the rhythmicity of LFP signals and their frequency components, but also shape neuronal patterns on much smaller time scales, as neuronal activity in Cry1/2−/− mice is significantly less regular but at each time more synchronous within and between brain areas than in wild-type mice. These results show that functional circadian rhythms are integral for both circadian and non-circadian coordination of neuronal ensemble dynamics

Early signaling, referral, and treatment of adolescent chronic pain: a study protocol

<p>Abstract</p> <p>Background</p> <p>Chronic pain is prevalent among young people and negatively influences their quality of life. Furthermore, chronic pain in adolescence may persist into adulthood. Therefore, it is important early on to promote the self-management skills of adolescents with chronic pain by improving signaling, referral, and treatment of these youngsters. In this study protocol we describe the designs of two complementary studies: a signaling study and an intervention study.</p> <p>Methods and design</p> <p>The signaling study evaluates the Pain Barometer, a self-assessed signaling instrument for chronic pain in adolescents. To evaluate the feasibility of the Pain Barometer, the experiences of youth-health care nurses will be evaluated in semi-structured interviews. Also, we will explore the frequencies of referral per health-care provider. The intervention study evaluates Move It Now, a guided self-help intervention via the Internet for teenagers with chronic pain. This intervention uses cognitive behavioural techniques, including relaxation exercises and positive thinking. The objective of the intervention is to improve the ability of adolescents to cope with pain. The efficacy of Move It Now will be examined in a randomized controlled trial, in which 60 adolescents will be randomly assigned to an experimental condition or a waiting list control condition.</p> <p>Discussion</p> <p>If the Pain Barometer is proven to be feasible and Move It Now appears to be efficacious, a health care pathway can be created to provide the best tailored treatment promptly to adolescents with chronic pain. Move It Now can be easily implemented throughout the Netherlands, as the intervention is Internet based.</p> <p>Trial registration</p> <p>Dutch Trial Register NTR1926</p

Establishing a multidisciplinary specialist centre for fetal alcohol spectrum disorders—Lessons learned from a model project in Germany

Background Inadequate coordination between relevant professionals hampers the provision of appropriate care for individuals with fetal alcohol spectrum disorder (FASD). Integrated, multidisciplinary care is thus urgently required. Hence, we aimed at establishing the first university-bound, interdisciplinary specialist centre for FASD in Germany, systematically collecting data on its utilisation and evaluation by attendees. Methods After our centre started to provide consultation and support services in July 2019 until May 2021, we collected 233 questionnaires on the centre's utilisation (including attendees' sociodemographic characteristics and the topics on which they requested consultation, e.g., general information about FASD, consultation on therapy options, and educational consultation). Ninety-four of 136 individuals who received consultation at our centre submitted an evaluation questionnaire that recorded attendees' satisfaction with the support they had received (e.g., the extent to which the consultation met their needs). Results Of 233 participants who completed the utilisation questionnaire, 81.8% were female, and 56.7% were aged 40 to 60 years. Moreover, 42% were foster parents, while 38% were professionals. Most attendees had questions on FASD in general as well as on a specific child or adolescent with FASD. Almost three quarters of the attendees requested consultation on adequate therapies for FASD patients, while 64% had questions on parenting issues. The overall quality of the consultation was rated very well. Discussion Our service was used by both caregivers and professionals who reported numerous and complex concerns and needs. Professionally sound and multidisciplinary services are viable instruments to meet those needs, bearing the potential for quick and notable relief among individuals affected. We propose further advancement of networking and coordination between care providers, the expansion of multidisciplinary services, and securing early diagnosis and consistency of care as relevant steps to even better support children and adolescents with FASD and their families in the future

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements