We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
We introduce a versatile high-repetition-rate solid tape target system suitable for relativistic laser-plasma driven secondary sources. We demonstrate the operation and stability monitoring based on a petawatt laser focused at 1 Hz. Experiments were carried out at the VEGA-3 laser system of the Centro de Láseres Pulsados facility where results for different tape materials and thicknesses are presented. Experimental proton spectra were recorded by a Thomson parabola spectrometer and a time-of-flight detector. In addition, non-invasive detectors, such as a target charging monitor and ionization chamber detectors, were tested as metrology for the stability of the source. Degradation of the proton signal at high-repetition-rate operation was observed and it was solved by online optimization of the relative focus position of the target and laser beam parameters. We report the use of the tape target for bursts of 1000 shots at 1 Hz with mean cut-off energies of about 10 MeV in optimized interaction conditions.
NASA’s all-sky survey mission, the Transiting Exoplanet Survey Satellite (TESS), is specifically engineered to detect exoplanets that transit bright stars. Thus far, TESS has successfully identified approximately 400 transiting exoplanets, in addition to roughly 6 000 candidate exoplanets pending confirmation. In this study, we present the results of our ongoing project, the Validation of Transiting Exoplanets using Statistical Tools (VaTEST). Our dedicated effort is focused on the confirmation and characterisation of new exoplanets through the application of statistical validation tools. Through a combination of ground-based telescope data, high-resolution imaging, and the utilisation of the statistical validation tool known as TRICERATOPS, we have successfully discovered eight potential super-Earths. These planets bear the designations: TOI-238b (1.61$^{+0.09} _{-0.10}$ R$_\oplus$), TOI-771b (1.42$^{+0.11} _{-0.09}$ R$_\oplus$), TOI-871b (1.66$^{+0.11} _{-0.11}$ R$_\oplus$), TOI-1467b (1.83$^{+0.16} _{-0.15}$ R$_\oplus$), TOI-1739b (1.69$^{+0.10} _{-0.08}$ R$_\oplus$), TOI-2068b (1.82$^{+0.16} _{-0.15}$ R$_\oplus$), TOI-4559b (1.42$^{+0.13} _{-0.11}$ R$_\oplus$), and TOI-5799b (1.62$^{+0.19} _{-0.13}$ R$_\oplus$). Among all these planets, six of them fall within the region known as ‘keystone planets’, which makes them particularly interesting for study. Based on the location of TOI-771b and TOI-4559b below the radius valley we characterised them as likely super-Earths, though radial velocity mass measurements for these planets will provide more details about their characterisation. It is noteworthy that planets within the size range investigated herein are absent from our own solar system, making their study crucial for gaining insights into the evolutionary stages between Earth and Neptune.
We report the first high-repetition-rate generation and simultaneous characterization of nanosecond-scale return currents of kA-magnitude issued by the polarization of a target irradiated with a PW-class high-repetition-rate titanium:sapphire laser system at relativistic intensities. We present experimental results obtained with the VEGA-3 laser at intensities from $5\times {10}^{18}$ to $1.3\times {10}^{20}$ W cm${}^{-2}$. A non-invasive inductive return-current monitor is adopted to measure the derivative of return currents of the order of kA ns${}^{-1}$ and analysis methodology is developed to derive return currents. We compare the current for copper, aluminium and Kapton targets at different laser energies. The data show the stable production of current peaks and clear prospects for the tailoring of the pulse shape, which is promising for future applications in high-energy-density science, for example, electromagnetic interference stress tests, high-voltage pulse response measurements and charged particle beam lensing. We compare the target discharge of the order of hundreds of nC with theoretical predictions and a good agreement is found.
Contact heat is commonly used in experimental research to evoke brain activity, most frequently acquired with electroencephalography (EEG). Although magnetoencephalography (MEG) improves spatial resolution, using some contact heat stimulators with MEG can present methodological challenges. This systematic review assesses studies that utilise contact heat in MEG, their findings and possible directions for further research.
Methods:
Eight electronic databases were searched for relevant studies, in addition to the selected papers' reference lists, citations and ConnectedPapers maps. Best practice recommendations for systematic reviews were followed. Papers met inclusion criteria if they used MEG to record brain activity in conjunction with contact heat, regardless of stimulator equipment or paradigm.
Results:
Of 646 search results, seven studies met the inclusion criteria. Studies demonstrated effective electromagnetic artefact removal from MEG data, the ability to elicit affective anticipation and differences in deep brain stimulation responders. We identify contact heat stimulus parameters that should be reported in publications to ensure comparisons between data outcomes are consistent.
Conclusions:
Contact heat is a viable alternative to laser or electrical stimulation in experimental research, and methods exist to successfully mitigate any electromagnetic noise generated by PATHWAY CHEPS equipment – though there is a dearth of literature exploring the post-stimulus time window.
The authors present preliminary results from a new research project based in Jebel Shaqadud, Sudan. Their findings highlight the potential for this region's archaeological record to expand our understanding of the adaptation strategies used by human groups in arid north-east African environments away from rivers and lakes during the Holocene. Furthermore, they present exceptionally early radiocarbon dates that push postglacial human occupation in the eastern Sahel back to the twelfth millennium BP.
Behaviors typical of body-focused repetitive behavior disorders such as trichotillomania (TTM) and skin-picking disorder (SPD) are often associated with pleasure or relief, and with little or no physical pain, suggesting aberrant pain perception. Conclusive evidence about pain perception and correlates in these conditions is, however, lacking.
Methods
A multisite international study examined pain perception and its physiological correlates in adults with TTM (n = 31), SPD (n = 24), and healthy controls (HCs; n = 26). The cold pressor test was administered, and measurements of pain perception and cardiovascular parameters were taken every 15 seconds. Pain perception, latency to pain tolerance, cardiovascular parameters and associations with illness severity, and comorbid depression, as well as interaction effects (group × time interval), were investigated across groups.
Results
There were no group differences in pain ratings over time (P = .8) or latency to pain tolerance (P = .8). Illness severity was not associated with pain ratings (all P > .05). In terms of diastolic blood pressure (DBP), the main effect of group was statistically significant (P = .01), with post hoc analyses indicating higher mean DBP in TTM (95% confidence intervals [CI], 84.0-93.5) compared to SPD (95% CI, 73.5-84.2; P = .01), and HCs (95% CI, 75.6-86.0; P = .03). Pain perception did not differ between those with and those without depression (TTM: P = .2, SPD: P = .4).
Conclusion
The study findings were mostly negative suggesting that general pain perception aberration is not involved in TTM and SPD. Other underlying drivers of hair-pulling and skin-picking behavior (eg, abnormal reward processing) should be investigated.
The mating system and mating strategies of a species refer to the behavioral strategies used to obtain reproductive partners and ensure reproductive success. Common determining factors of mating systems and strategies are: the manner of mate acquisition, the number of mates obtained by an individual, as well as the absence or presence and duration of parental care. In mammals, the energetic investments in gametes and rearing offspring are typically larger for females than for males. Mate selection is thus a much more important decision for females than for the rather indiscriminate males. This dichotomy results in sexual selection, which in turn is determined by male–male competition for access to females, as well as female mate choice. Because receptive females are generally considered the limiting resource in reproduction, males face intrasexual competition for mates. In a multitude of mammalian species, including bears, this has resulted in pronounced sexual size dimorphism and polygamous mating systems. Despite common characteristics (e.g. sexual size dimorphism, polygamy), variation in mating systems and strategies occur among bear populations and species.
The inclusion of students with autism spectrum disorder (ASD) is increasing, but there have been no longitudinal studies of included students in Australia. Interview data reported in this study concern primary school children with ASD enrolled in mainstream classes in South Australia and New South Wales, Australia. In order to examine perceived facilitators and barriers to inclusion, parents, teachers, and principals were asked to comment on the facilitators and barriers to inclusion relevant to each child. Data are reported about 60 students, comprising a total of 305 parent interviews, 208 teacher interviews, and 227 principal interviews collected at 6-monthly intervals over 3.5 years. The most commonly mentioned facilitator was teacher practices. The most commonly mentioned barrier was intrinsic student factors. Other factors not directly controllable by school staff, such as resource limitations, were also commonly identified by principals and teachers. Parents were more likely to mention school- or teacher-related barriers. Many of the current findings were consistent with previous studies but some differences were noted, including limited reporting of sensory issues and bullying as barriers. There was little change in the pattern of facilitators and barriers identified by respondents over time. A number of implications for practice and directions for future research are discussed.
Studies suggest that alcohol consumption and alcohol use disorders have distinct genetic backgrounds.
Methods
We examined whether polygenic risk scores (PRS) for consumption and problem subscales of the Alcohol Use Disorders Identification Test (AUDIT-C, AUDIT-P) in the UK Biobank (UKB; N = 121 630) correlate with alcohol outcomes in four independent samples: an ascertained cohort, the Collaborative Study on the Genetics of Alcoholism (COGA; N = 6850), and population-based cohorts: Avon Longitudinal Study of Parents and Children (ALSPAC; N = 5911), Generation Scotland (GS; N = 17 461), and an independent subset of UKB (N = 245 947). Regression models and survival analyses tested whether the PRS were associated with the alcohol-related outcomes.
Results
In COGA, AUDIT-P PRS was associated with alcohol dependence, AUD symptom count, maximum drinks (R2 = 0.47–0.68%, p = 2.0 × 10−8–1.0 × 10−10), and increased likelihood of onset of alcohol dependence (hazard ratio = 1.15, p = 4.7 × 10−8); AUDIT-C PRS was not an independent predictor of any phenotype. In ALSPAC, the AUDIT-C PRS was associated with alcohol dependence (R2 = 0.96%, p = 4.8 × 10−6). In GS, AUDIT-C PRS was a better predictor of weekly alcohol use (R2 = 0.27%, p = 5.5 × 10−11), while AUDIT-P PRS was more associated with problem drinking (R2 = 0.40%, p = 9.0 × 10−7). Lastly, AUDIT-P PRS was associated with ICD-based alcohol-related disorders in the UKB subset (R2 = 0.18%, p < 2.0 × 10−16).
Conclusions
AUDIT-P PRS was associated with a range of alcohol-related phenotypes across population-based and ascertained cohorts, while AUDIT-C PRS showed less utility in the ascertained cohort. We show that AUDIT-P is genetically correlated with both use and misuse and demonstrate the influence of ascertainment schemes on PRS analyses.
Social patterning of infectious diseases is increasingly recognised. Previous studies of social determinants of acute respiratory illness (ARI) have found that highly educated and lower income families experience more illnesses. Subjective social status (SSS) has also been linked to symptomatic ARI, but the association may be confounded by household composition. We examined SSS and ARI in the Household Influenza Vaccine Evaluation (HIVE) Study in 2014–2015. We used SSS as a marker of social disadvantage and created a workplace disadvantage score for working adults. We examined the association between these measures and ARI incidence using mixed-effects Poisson regression models with random intercepts to account for household clustering. In univariate analyses, mean ARI was higher among children <5 years old (P < 0.001), and females (P = 0.004) at the individual level. At the household level, mean ARI was higher for households with at least one child <5 years than for those without (P = 0.002). In adjusted models, individuals in the lowest tertile of SSS had borderline significantly higher rates of ARI than those in the highest tertile (incidence rate ratio (IRR) 1.34, 95% confidence interval (CI) 0.98–1.92). Households in the lowest tertile of SSS had significantly higher ARI incidence in household-level models (IRR 1.46, 95% CI 1.05–2.03). We observed no association between workplace disadvantage and ARI. We detected an increase in the incidence of ARI for households with low SSS compared with those with high SSS, suggesting that socio-economic position has a meaningful impact on ARI incidence.
OBJECTIVES/SPECIFIC AIMS: A hallmark of progressive HIV-1 infection is the massive activation and depletion of the gut barrier protective CD4 T helper subsets (Th17 and Th22) in the intestinal mucosa. The loss of these cells is thought to contribute to microbial translocation and systemic immune activation that occurs during chronic infection. In addition to the loss of protective Th subsets, we previously showed that chronically HIV-1 infected individuals have an altered colonic mucosal microbiome, which is in part characterized by a lower relative abundance of bacteria that produce the short-chain fatty acid butyrate in conjunction with increased relative abundance of gram-negative pathobionts. This dysbiosis was linked to markers of mucosal and systemic immune activation in these individuals. Following up on these clinical observations, we sought to understand how a loss of butyrate might contribute to HIV-associated inflammation. Initial studies showed that the addition of butyrate to cultured lamina propria mononuclear cells (LPMC) resulted in decreased pathobiont-driven gut T cell activation, HIV-1 infection levels and production of IL-17 and IFNy. Since the gut barrier protective Th17 and Th22 subsets are preferentially infected and depleted, which is critical to HIV-1 pathogenesis, we wanted to determine the mechanism by which butyrate modulates activation of these important Th subsets in the gut. METHODS/STUDY POPULATION: Total LPMCs or purified LP CD4 T cells were isolated from human jejunal tissue (n=3–6), labeled with CFSE and cultured with TCR/CD28 beads to mimic APC driven T cell activation, with the addition of butyrate at physiologic doses(0–2 mM). Four days after culture, secreted cytokine(IL-17 and IFNy) levels were measured by ELISA. Cells were then short-term (4 hr) mitogenically stimulated (PMA/Ionomycin) in the presence of a golgi transport inhibitor. Total CD4 T cell activation (CD38+/HLA-DR+, CD25+), proliferation (CFSElow), and frequencies of intracellular cytokines were measured by multi-color flow cytometry. Paired t-tests were performed to determine statistical significance. RESULTS/ANTICIPATED RESULTS: Butyrate inhibited LP CD4 T cell activation (p=0.013) and proliferation (p=0.015) within total LPMCs stimulated with TCR/CD28 beads in a dose-dependent manner, with significant activity starting at 0.125 mM. Quantification of total secreted cytokines revealed that butyrate significantly decreased both IL-17 and IFNy production after 4 days of culture at 0.0625 mM and 0.25 mM of butyrate, respectively. Assays using purified LP CD4 T cells demonstrated that butyrate directly decreased LP CD4 T cell activation, proliferation and cytokine production in response to TCR/CD28 stimulation. Studies on specific T helper subsets revealed that butyrate inhibited proliferation of Th17 cells at lower concentrations (IC50:0.147 mM) compared with Th1 (IC50:0.229 mM) and Th22 (IC50:0.258 mM) and Th non-IL-22/IL-17/IFNy producing (IC50:2.14 mM) subsets. In addition, it appeared there was a paradoxical increase of HIV-1 infection levels at lower concentrations of butyrate (0.125 mM). DISCUSSION/SIGNIFICANCE OF IMPACT: The addition of butyrate to activated LP CD4 T cells decreases TCR-mediated activation in a dose-dependent manner, and butyrate acts directly on purified LP CD4 T cell populations independent of other cell populations. Butyrate differentially inhibited the proliferation of Th17, Th1, and Th22 subsets, with Th17 cells being the most sensitive to butyrate but increased the infection levels of all T helper subsets at low concentrations. Further studies are needed to determine the mechanism of butyrate’s actions on LP Th cells and the sensitivity of Th17 cells to the inhibitory effects of butyrate. These results could help direct targeted manipulation of the colonic microbiome of HIV-1 infected individuals to help resolve inflammation and limit the impact of the infection in the gut mucosa and systemically.
The deep subsurface of other planetary bodies is of special interest for robotic and human exploration. The subsurface provides access to planetary interior processes, thus yielding insights into planetary formation and evolution. On Mars, the subsurface might harbour the most habitable conditions. In the context of human exploration, the subsurface can provide refugia for habitation from extreme surface conditions. We describe the fifth Mine Analogue Research (MINAR 5) programme at 1 km depth in the Boulby Mine, UK in collaboration with Spaceward Bound NASA and the Kalam Centre, India, to test instruments and methods for the robotic and human exploration of deep environments on the Moon and Mars. The geological context in Permian evaporites provides an analogue to evaporitic materials on other planetary bodies such as Mars. A wide range of sample acquisition instruments (NASA drills, Small Planetary Impulse Tool (SPLIT) robotic hammer, universal sampling bags), analytical instruments (Raman spectroscopy, Close-Up Imager, Minion DNA sequencing technology, methane stable isotope analysis, biomolecule and metabolic life detection instruments) and environmental monitoring equipment (passive air particle sampler, particle detectors and environmental monitoring equipment) was deployed in an integrated campaign. Investigations included studying the geochemical signatures of chloride and sulphate evaporitic minerals, testing methods for life detection and planetary protection around human-tended operations, and investigations on the radiation environment of the deep subsurface. The MINAR analogue activity occurs in an active mine, showing how the development of space exploration technology can be used to contribute to addressing immediate Earth-based challenges. During the campaign, in collaboration with European Space Agency (ESA), MINAR was used for astronaut familiarization with future exploration tools and techniques. The campaign was used to develop primary and secondary school and primary to secondary transition curriculum materials on-site during the campaign which was focused on a classroom extra vehicular activity simulation.
We present the first data release of the SkyMapper Southern Survey, a hemispheric survey carried out with the SkyMapper Telescope at Siding Spring Observatory in Australia. Here, we present the survey strategy, data processing, catalogue construction, and database schema. The first data release dataset includes over 66 000 images from the Shallow Survey component, covering an area of 17 200 deg2 in all six SkyMapper passbands uvgriz, while the full area covered by any passband exceeds 20 000 deg2. The catalogues contain over 285 million unique astrophysical objects, complete to roughly 18 mag in all bands. We compare our griz point-source photometry with Pan-STARRS1 first data release and note an RMS scatter of 2%. The internal reproducibility of SkyMapper photometry is on the order of 1%. Astrometric precision is better than 0.2 arcsec based on comparison with Gaia first data release. We describe the end-user database, through which data are presented to the world community, and provide some illustrative science queries.
Aquatic dissolved organic matter (DOM) is a major reservoir of reduced organic carbon and has a significant influence on heterotrophic biological productivity and water quality in marine and freshwater environments. Although the forms and transformations of DOM in temperate aquatic and soil environments have been studied extensively, this is not the case for glacial environments. In this study, fluorescent excitation–emission matrices (EEMs), parallel factor analysis (PARAFAC) and cluster analysis were used to characterize the fluorescing components of DOM in ice and water samples from supraglacial, englacial, subglacial and proglacial environments of seven glaciers in the Canadian Arctic, Norway and Antarctica. At least five significant fluorescent DOM fractions were identified, which accounted for 98.2% of the variance in the dataset. These included four protein-like components and one humic-like component. The predominantly proteinaceous character of DOM from these glaciers is very different from the more humic character of DOM described previously from lacustrine, fluvial, estuarine and marine environments. DOM from the sampled glaciers is broadly similar in character despite their geographically distinct locations, different thermal regimes and inter- and intra-site differences in potential organic matter sources. Glacier ice samples had a relatively low ratio of humic-like :protein-like fluorescence while meltwater samples had a higher ratio.
The Randolph Glacier Inventory (RGI) is a globally complete collection of digital outlines of glaciers, excluding the ice sheets, developed to meet the needs of the Fifth Assessment of the Intergovernmental Panel on Climate Change for estimates of past and future mass balance. The RGI was created with limited resources in a short period. Priority was given to completeness of coverage, but a limited, uniform set of attributes is attached to each of the ~198 000 glaciers in its latest version, 3.2. Satellite imagery from 1999–2010 provided most of the outlines. Their total extent is estimated as 726 800 ± 34 000 km2. The uncertainty, about ±5%, is derived from careful single-glacier and basin-scale uncertainty estimates and comparisons with inventories that were not sources for the RGI. The main contributors to uncertainty are probably misinterpretation of seasonal snow cover and debris cover. These errors appear not to be normally distributed, and quantifying them reliably is an unsolved problem. Combined with digital elevation models, the RGI glacier outlines yield hypsometries that can be combined with atmospheric data or model outputs for analysis of the impacts of climatic change on glaciers. The RGI has already proved its value in the generation of significantly improved aggregate estimates of glacier mass changes and total volume, and thus actual and potential contributions to sea-level rise.
Observations show that glaciers around the world are in retreat and losing mass. Internationally coordinated for over a century, glacier monitoring activities provide an unprecedented dataset of glacier observations from ground, air and space. Glacier studies generally select specific parts of these datasets to obtain optimal assessments of the mass-balance data relating to the impact that glaciers exercise on global sea-level fluctuations or on regional runoff. In this study we provide an overview and analysis of the main observational datasets compiled by the World Glacier Monitoring Service (WGMS). The dataset on glacier front variations (∼42 000 since 1600) delivers clear evidence that centennial glacier retreat is a global phenomenon. Intermittent readvance periods at regional and decadal scale are normally restricted to a subsample of glaciers and have not come close to achieving the maximum positions of the Little Ice Age (or Holocene). Glaciological and geodetic observations (∼5200 since 1850) show that the rates of early 21st-century mass loss are without precedent on a global scale, at least for the time period observed and probably also for recorded history, as indicated also in reconstructions from written and illustrated documents. This strong imbalance implies that glaciers in many regions will very likely suffer further ice loss, even if climate remains stable.