A central goal of comparative plant ecology is to understand how functional traits vary among species and to what extent this variation has adaptive value. Here we evaluate relationships between four ...functional traits (seed volume, specific leaf area, wood density, and adult stature) and two demographic attributes (diameter growth and tree mortality) for large trees of 240 tree species from Neotropical forests. We evaluate how these key functional traits are related to survival and growth and whether similar relationships between traits and demography hold across different tropical forests. There was a tendency for a trade-off between growth and survival across rain forest tree species. Wood density, seed volume, and adult stature were significant predictors of growth and/or mortality. Both growth and mortality rates declined with an increase in wood density. This is consistent with greater construction costs and greater resistance to stem damage for denser wood. Growth and mortality rates also declined as seed volume increased. This is consistent with an adaptive syndrome in which species tolerant of low resource availability (in this case shade-tolerant species) have large seeds to establish successfully and low inherent growth and mortality rates. Growth increased and mortality decreased with an increase in adult stature, because taller species have a greater access to light and longer life spans. Specific leaf area was, surprisingly, only modestly informative for the performance of large trees and had ambiguous relationships with growth and survival. Single traits accounted for 9—55% of the interspecific variation in growth and mortality rates at individual sites. Significant correlations with demographic rates tended to be similar across forests and for phylogenetically independent contrasts as well as for cross-species analyses that treated each species as an independent observation. In combination, the morphological traits explained 41% of the variation in growth rate and 54% of the variation in mortality rate, with wood density being the best predictor of growth and mortality. Relationships between functional traits and demographic rates were statistically similar across a wide range of Neotropical forests. The consistency of these results strongly suggests that tropical rain forest species face similar trade-offs in different sites and converge on similar sets of solutions.
We provide an overview of the design and capabilities of the near-infrared spectrograph (NIRSpec) onboard the
James Webb
Space Telescope. NIRSpec is designed to be capable of carrying out ...low-resolution (
R
= 30−330) prism spectroscopy over the wavelength range 0.6–5.3 μm and higher resolution (
R
= 500−1340 or
R
= 1320−3600) grating spectroscopy over 0.7–5.2 μm, both in single-object mode employing any one of five fixed slits, or a 3.1 × 3.2 arcsec
2
integral field unit, or in multiobject mode employing a novel programmable micro-shutter device covering a 3.6 × 3.4 arcmin
2
field of view. The all-reflective optical chain of NIRSpec and the performance of its different components are described, and some of the trade-offs made in designing the instrument are touched upon. The faint-end spectrophotometric sensitivity expected of NIRSpec, as well as its dependency on the energetic particle environment that its two detector arrays are likely to be subjected to in orbit are also discussed.
Fitspiration is a popular social media trend containing images, quotes and advice related to exercise and healthy eating. This study aimed to 1) describe the types of fitspiration content that users ...access and how they engage with content, 2) investigate the disordered eating and exercise behaviours and psychological distress of individuals who access fitspiration, and 3) understand the perceived influence of fitspiration on health and wellbeing.
Participants who access fitspiration content were recruited via social media to complete a cross-sectional online survey. Participants' psychological distress was measured using the Kessler 10 Psychological Distress Scale (K10); disordered eating behaviours using the Eating Attitudes Test-26 (EAT-26); and compulsive exercise behaviours using the Exercise Addiction Inventory (EAI). Participants also answered a series of open-ended questions about their experiences with fitspiration. A descriptive statistical analysis was conducted for quantitative data. Responses to open-ended questions were analysed for key themes using an iterative process of open, axial and thematic coding.
Participants (N = 180, 151 female, median age 23.0 years (IQR 19.0, 28.5)) most commonly accessed content posted by personal trainers and athletes (59.4%), posts tagged with the 'fitspiration' hashtag (53.9%) and posted by 'everyday' people (53.3%). Overall, 17.7% of participants were classified as high risk for an eating disorder, 17.4% reported very high levels of psychological distress, and 10.3% were at risk of addictive exercise behaviours. Participants described both positive and negative influences of engaging with fitspiration content. The influence on their health beliefs and behaviours was explained through four key themes: 1) Setting the 'healthy ideal', 2) Failure to achieve the 'ideal', 3) Being part of a community, and 4) Access to reliable health information.
Many participants reported benefits of fitspiration content including increased social support and access to health information. However, participants also reported that fitspiration content could negatively influence their wellbeing and perception of healthy goals. Content posted by relatable individuals or qualified experts was perceived as most trustworthy. Future research is needed to determine the individual and content-related factors associated with negative and positive fitspiration experiences.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
With the conclusion of the third observing run for Advanced LIGO/Virgo (O3), we present a detailed analysis of both triggered and serendipitous observations of 17 gravitational-wave (GW) ...events (7 triggered and 10 purely serendipitous) from the Searches After Gravitational-waves Using ARizona Observatories (SAGUARO) program. We searched a total of 4935 deg
2
down to a median 5
σ
transient detection depth of 21.1 AB mag using the Mt. Lemmon 1.5 m telescope, the discovery engine for SAGUARO. In addition to triggered events within 24 hr, our transient search encompassed a time interval following GW events of <120 hr, providing observations on ∼1/2 of the events accessible to the Mt. Lemmon 1.5 m telescope. We covered 2.1%–86% of the LVC total probability (
P
total
) for individual events, with a median
P
total
≈ 8% within <120 hr. Following improvements to our pipeline and the addition of serendipitous observations, we find a total of seven new optical candidates across five GW events, which we are unable to rule out after searching for additional information and comparing to kilonova models. Using both publicly available and our own late-time data, we investigated a total of 252 optical candidates for these 17 events, finding that only 65% were followed up in some capacity by the community. Of the total 252 candidates, we are able to rule out an additional 12 previously reported counterpart candidates. In light of these results, we discuss lessons learned from the SAGUARO GW counterpart search. We discuss how community coordination of observations and candidate follow-up, as well as the role of archival data, are crucial to improving the efficiency of follow-up efforts and preventing unnecessary duplication of effort with limited electromagnetic resources.
The amount of alcohol consumed during an occasion can be influenced by physical and social attributes of the setting, characteristics and state of individuals, and the interactions of these ...components. This systematic review identifies and describes the specific combinations and sequences of context-related factors that are associated with heavy drinking occasions.
We conducted a systematic literature search of MEDLINE, Embase and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. Eligible articles were event-level and event-based studies that quantitatively analysed associations of sequences or combinations of context-related factors with event-level alcohol consumption. We extracted information on study design, sample, variables, effect estimates and analytical methods. We compiled a list of combinations and sequences associated with heavier drinking (i.e., 'risky contexts') and with lighter drinking ('protective contexts'). The review protocol was registered with PROSPERO (registration number: CRD42018089500).
We screened 1902 retrieved records and identified a final sample of 65 eligible studies. Daily mood, day of week, location and drinking group characteristics are important drivers of whether an individual engages in a heavy drinking occasion. The direction and magnitude of some associations differed by gender, age, personality and motives, such that in particular social or physical contexts, some people may feel compelled to drink more while others are compelled to drink less. Very few sequences of factors were reported as being associated with event-level alcohol consumption.
Contexts or factors are experienced in specific sequences that shape the broader drinking context and influence drinking behaviours and consequences but are under-studied. Event-level studies such as those using ecological momentary assessment can harness new technologies for data collection and analysis to improve understandings of why people engage in heavy drinking. Continued event-level research will facilitate public health interventions and policies that reduce heavy drinking and alcohol-related harms.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Although common sense suggests that environmental influences increasingly account for individual differences in behavior as experiences accumulate during the course of life, this hypothesis has not ...previously been tested, in part because of the large sample sizes needed for an adequately powered analysis. Here we show for general cognitive ability that, to the contrary, genetic influence increases with age. The heritability of general cognitive ability increases significantly and linearly from 41% in childhood (9 years) to 55% in adolescence (12 years) and to 66% in young adulthood (17 years) in a sample of 11 000 pairs of twins from four countries, a larger sample than all previous studies combined. In addition to its far-reaching implications for neuroscience and molecular genetics, this finding suggests new ways of thinking about the interface between nature and nurture during the school years. Why, despite life's 'slings and arrows of outrageous fortune', do genetically driven differences increasingly account for differences in general cognitive ability? We suggest that the answer lies with genotype-environment correlation: as children grow up, they increasingly select, modify and even create their own experiences in part based on their genetic propensities.
Summary Objective To evaluate the clinical effectiveness of manual physiotherapy and/or exercise physiotherapy in addition to usual care for patients with osteoarthritis (OA) of the hip or knee. ...Design In this 2 × 2 factorial randomized controlled trial, 206 adults (mean age 66 years) who met the American College of Rheumatology criteria for hip or knee OA were randomly allocated to receive manual physiotherapy ( n = 54), multi-modal exercise physiotherapy ( n = 51), combined exercise and manual physiotherapy ( n = 50), or no trial physiotherapy ( n = 51). The primary outcome was change in the Western Ontario and McMaster osteoarthritis index (WOMAC) after 1 year. Secondary outcomes included physical performance tests. Outcome assessors were blinded to group allocation. Results Of 206 participants recruited, 193 (93.2%) were retained at follow-up. Mean (SD) baseline WOMAC score was 100.8 (53.8) on a scale of 0–240. Intention to treat analysis showed adjusted reductions in WOMAC scores at 1 year compared with the usual care group of 28.5 (95% confidence interval (CI) 9.2–47.8) for usual care plus manual therapy, 16.4 (−3.2 to 35.9) for usual care plus exercise therapy, and 14.5 (−5.2 to 34.1) for usual care plus combined exercise therapy and manual therapy. There was an antagonistic interaction between exercise therapy and manual therapy ( P = 0.027). Physical performance test outcomes favoured the exercise therapy group. Conclusions Manual physiotherapy provided benefits over usual care, that were sustained to 1 year. Exercise physiotherapy also provided physical performance benefits over usual care. There was no added benefit from a combination of the two therapies. Trial registration number Australian New Zealand Clinical Trials Registry ACTRN12608000130369.
Background. Infection is a serious complication of left ventricular assist device (LVAD) therapy. Published data regarding LVAD-associated infections (LVADIs) are limited by single-center experiences ...and use of nonstandardized definitions. Methods. We retrospectively reviewed 247 patients who underwent continuous-flow LVAD implantation from January 2005 to December 2011 at Mayo Clinic campuses in Minnesota, Arizona, and Florida. LVADIs were defined using the International Society for Heart and Lung Transplantation criteria. Results. We identified 101 episodes of LVADI in 78 patients (32%) from this cohort. Mean age (± standard deviation SD) was 57±15 years. The majority (94%) underwent Heartmate II implantation, with 62% LVADs placed as destination therapy. The most common type of LVADIs were driveline infections (47%), followed by bloodstream infections (24% VAD related, and 22% non-VAD related). The most common causative pathogens included grampositive cocci (45%), predominantly staphylococci, and nosocomial gram-negative bacilli (27%). Almost half (42%) of the patients were managed by chronic suppressive antimicrobial therapy. While 14% of the patients had intraoperative debridement, only 3 underwent complete LVAD removal. The average duration (±SD) of LVAD support was 1.5±1.0 years. At year 2 of follow-up, the cumulative incidence of all-cause mortality was estimated to be 43%. Conclusion. Clinical manifestations of LVADI vary on the basis of the type of infection and the causative pathogen. Mortality remained high despite combined medical and surgical intervention and chronic suppressive antimicrobial therapy. Based on clinical experiences, a management algorithm for LVADI is proposed to assist in the decision-making process.
Overview of the SPARC tokamak Creely, A. J.; Greenwald, M. J.; Ballinger, S. B. ...
Journal of plasma physics,
10/2020, Letnik:
86, Številka:
5
Journal Article
Recenzirano
Odprti dostop
The SPARC tokamak is a critical next step towards commercial fusion energy. SPARC is designed as a high-field ($B_0 = 12.2$ T), compact ($R_0 = 1.85$ m, $a = 0.57$ m), superconducting, D-T tokamak ...with the goal of producing fusion gain $Q>2$ from a magnetically confined fusion plasma for the first time. Currently under design, SPARC will continue the high-field path of the Alcator series of tokamaks, utilizing new magnets based on rare earth barium copper oxide high-temperature superconductors to achieve high performance in a compact device. The goal of $Q>2$ is achievable with conservative physics assumptions ($H_{98,y2} = 0.7$) and, with the nominal assumption of $H_{98,y2} = 1$, SPARC is projected to attain $Q \approx 11$ and $P_{\textrm {fusion}} \approx 140$ MW. SPARC will therefore constitute a unique platform for burning plasma physics research with high density ($\langle n_{e} \rangle \approx 3 \times 10^{20}\ \textrm {m}^{-3}$), high temperature ($\langle T_e \rangle \approx 7$ keV) and high power density ($P_{\textrm {fusion}}/V_{\textrm {plasma}} \approx 7\ \textrm {MW}\,\textrm {m}^{-3}$) relevant to fusion power plants. SPARC's place in the path to commercial fusion energy, its parameters and the current status of SPARC design work are presented. This work also describes the basis for global performance projections and summarizes some of the physics analysis that is presented in greater detail in the companion articles of this collection.
PDF
