Adolescent cannabis use, change in neurocognitive function, and high-school graduation: A longitudinal study from early adolescence to young adulthood

The main objective of this prospective longitudinal study was to investigate bidirectional associations between adolescent cannabis use (CU) and neurocognitive performance in a community sample of 294 young men from ages 13 to 20 years. The results showed that in early adolescence, and prior to initiation to CU, poor short-term and working memory, but high verbal IQ, were associated with earlier age of onset of CU. In turn, age of CU onset and CU frequency across adolescence were associated with (a) specific neurocognitive decline in verbal IQ and executive function tasks tapping trial and error learning and reward processing by early adulthood and (b) lower rates of high-school graduation. The association between CU onset and change in neurocognitive function, however, was found to be accounted for by CU frequency. Whereas the link between CU frequency across adolescence and change in verbal IQ was explained (mediated) by high school graduation, the link between CU frequency and tasks tapping trial and error learning were independent from high school graduation, concurrent cannabis and other substance use, adolescent alcohol use, and externalizing behaviors. Findings support prevention efforts aimed at delaying onset and reducing frequency of CU

Short-scale turbulent fluctuations driven by the electron-temperature gradient in the national spherical torus experiment

Measurements with coherent scattering of electromagnetic waves in plasmas of the National Spherical Torus Experiment indicate the existence of turbulent fluctuations in the range of wave numbers k(perpendicular to)rho(e)=0.1-0.4, corresponding to a turbulence scale length nearly equal to the collisionless skin depth. Experimental observations and agreement with numerical results from a linear gyrokinetic stability code support the conjecture that the observed turbulence is driven by the electron-temperature gradient.X1155sciescopu

Reversible protein affinity-labelling using bromomaleimide-based reagents

Reversible protein biotinylation is readily affected via conjugation with a bromomaleimide-based reagent followed by reductive cleavage. The intermediate biotinylated protein constructs are stable at physiological temperature and pH 8.0. Quantitative reversibility is elegantly delivered under mild conditions of using a stoichiometric amount of a bis-thiol, thus providing an approach that will be of general interest in chemical biology and proteomics

Nature reserves as catalysts for landscape change

Scientists have called repeatedly for a broader conservation agenda that emphasizes not only protected areas but also the landscapes in which those areas are embedded. We describe key advances in the science and practice of engaging private landowners in biodiversity conservation and propose a conceptual model for integrating conservation management on reserves and privately owned lands. The overall goal of our model is to blur the distinction between land management on reserves and the surrounding landscapes in a way that fosters widespread implementation of conservation practices. Reserves assume a new role as natural laboratories where alternative land-use practices, designed to achieve conservation objectives, can be explored. We articulate the details of the model using a case study from the North American tallgrass prairie ecoregion.Peer reviewedNatural Resource Ecology and Managemen

Evidence of Combat in Triceratops

Background: The horns and frill of Triceratops and other ceratopsids (horned dinosaurs) are interpreted variously as display structures or as weapons against conspecifics and predators. Lesions (in the form of periosteal reactive bone, healing fractures, and alleged punctures) on Triceratops skulls have been used as anecdotal support of intraspecific combat similar to that in modern horned and antlered animals. If ceratopsids with different cranial morphologies used their horns in such combat, this should be reflected in the rates of lesion occurrence across the skull. Methodology/Principal Findings: We used a G-test of independence to compare incidence rates of lesions in Triceratops (which possesses two large brow horns and a smaller nasal horn) and the related ceratopsid Centrosaurus (with a large nasal horn and small brow horns), for the nasal, jugal, squamosal, and parietal bones of the skull. The two taxa differ significantly in the occurrence of lesions on the squamosal bone of the frill (P = 0.002), but not in other cranial bones (P.0.20). Conclusions/Significance: This pattern is consistent with Triceratops using its horns in combat and the frill being adapted as a protective structure for this taxon. Lower pathology rates in Centrosaurus may indicate visual rather than physical use o

Motivated learning with digital learning tasks: what about autonomy and structure?

Article about Motivated learning with digital learning tasks: what about autonomy and structure

Two Stellar Components in the Halo of the Milky Way

The halo of the Milky Way provides unique elemental abundance and kinematic information on the first objects to form in the Universe, which can be used to tightly constrain models of galaxy formation and evolution. Although the halo was once considered a single component, evidence for its dichotomy has slowly emerged in recent years from inspection of small samples of halo objects. Here we show that the halo is indeed clearly divisible into two broadly overlapping structural components -- an inner and an outer halo -- that exhibit different spatial density profiles, stellar orbits and stellar metallicities (abundances of elements heavier than helium). The inner halo has a modest net prograde rotation, whereas the outer halo exhibits a net retrograde rotation and a peak metallicity one-third that of the inner halo. These properties indicate that the individual halo components probably formed in fundamentally different ways, through successive dissipational (inner) and dissipationless (outer) mergers and tidal disruption of proto-Galactic clumps.Comment: Two stand-alone files in manuscript, concatenated together. The first is for the main paper, the second for supplementary information. The version is consistent with the version published in Natur

FIGS-Faint Infrared Grism Survey: Description and Data Reduction

The Faint Infrared Grism Survey (FIGS) is a deep Hubble Space Telescope (HST) WFC3/IR (Wide Field Camera 3 Infrared) slitless spectroscopic survey of four deep fields. Two fields are located in the Great Observatories Origins Deep Survey-North (GOODS-N) area and two fields are located in the Great Observatories Origins Deep Survey-South (GOODS-S) area. One of the southern fields selected is the Hubble Ultra Deep Field. Each of these four fields were observed using the WFC3/G102 grism (0.8 μm–1.15 μm continuous coverage) with a total exposure time of 40 orbits (≈100 kilo-seconds) per field. This reaches a $3\sigma$ continuum depth of $\approx 26$ AB magnitudes and probes emission lines to $\sim {10}^{-17}\,\mathrm{erg}\,{{\rm{s}}}^{-1}\,{\mathrm{cm}}^{-2}$. This paper details the four FIGS fields and the overall observational strategy of the project. A detailed description of the Simulation Based Extraction (SBE) method used to extract and combine over 10,000 spectra of over 2000 distinct sources brighter than ${m}_{F105W}=26.5$ mag is provided. High fidelity simulations of the observations is shown to significantly improve the background subtraction process, the spectral contamination estimates, and the final flux calibration. This allows for the combination of multiple spectra to produce a final high quality, deep, 1D spectra for each object in the survey

‘Nedoceratops’: An Example of a Transitional Morphology

Background: The holotype and only specimen of the chasmosaurine ceratopsid dinosaur ‘Nedoceratops hatcheri ’ has been the source of considerable taxonomic debate since its initial description. At times it has been referred to its own genus while at others it has been considered synonymous with the contemporaneous chasmosaurine Triceratops. Most recently, the debate has focused on whether the specimen represents an intermediate ontogenetic stage between typical young adult Triceratops and the proposed mature morphology, which was previously considered to represent a distinct genus, ‘Torosaurus’. Methodology/Principal Findings: The only specimen of ‘Nedoceratops hatcheri ’ was examined and the proposed diagnostic features of this taxon were compared with other chasmosaurine ceratopsids. Every suggested autapomorphy of ‘Nedoceratops ’ is found in specimens of Triceratops. In this study, Triceratops includes the adult ‘Torosaurus ’ morphology. The small parietal fenestra and elongate squamosals of Nedoceratops are consistent with a transition from a short, solid parietalsquamosal frill to an expanded, fenestrated condition. Objections to this hypothesis regarding the number of epiossifications of the frill and alternations of bone surface texture were explored through a combination of comparative osteology and osteohistology. The synonymy of the three taxa was further supported by these investigations. Conclusions/Significance: The Triceratops, ‘Torosaurus’, and ‘Nedoceratops ’ morphologies represent ontogenetic variatio

Experiences of treatment decision making for young people diagnosed with depressive disorders: a qualitative study in primary care and specialist mental health settings

<p>Abstract</p> <p>Background</p> <p>Clinical guidelines advocate for the inclusion of young people experiencing depression as well as their caregivers in making decisions about their treatment. Little is known, however, about the degree to which these groups are involved, and whether they want to be. This study sought to explore the experiences and desires of young people and their caregivers in relation to being involved in treatment decision making for depressive disorders.</p> <p>Methods</p> <p>Semi-structured interviews were carried out with ten young people and five caregivers from one primary care and one specialist mental health service about their experiences and beliefs about treatment decision making. Interviews were audio taped, transcribed verbatim and analysed using thematic analysis.</p> <p>Results</p> <p>Experiences of involvement for clients varied and were influenced by clients themselves, clinicians and service settings. For caregivers, experiences of involvement were more homogenous. Desire for involvement varied across clients, and within clients over time; however, most clients wanted to be involved at least some of the time. Both clients and caregivers identified barriers to involvement.</p> <p>Conclusions</p> <p>This study supports clinical guidelines that advocate for young people diagnosed with depressive disorders to be involved in treatment decision making. In order to maximise engagement, involvement in treatment decision making should be offered to all clients. Involvement should be negotiated explicitly and repeatedly, as desire for involvement may change over time. Caregiver involvement should be negotiated on an individual basis; however, all caregivers should be supported with information about mental disorders and treatment options.</p