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The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.
In the current opioid epidemic, identifying high-risk patients among those with substance and opioid use may prevent deaths. The objective of this study was to determine whether frequent emergency department (ED) use and degree of frequent use are associated with mortality among ED patients with substance and opioid use.
This cohort study used linked population-based ED (National Ambulatory Care Reporting System) and mortality data from Alberta. All adults ≥ 18 years with substance or opioid use-related visits based on diagnostic codes from April 1, 2012, to March 31, 2013, were included (n = 16,389). Frequent use was defined by ≥ 5 visits in the previous year. Outcomes were unadjusted and adjusted (for age, sex, income) mortality within 90 days (primary), and 30 days, 365 days, and 2 years (secondary). To examine degree, frequent use was subcategorized into 5–10, 11–15, 16–20, and > 20 visits.
Frequent users were older, lower income, and made lower acuity visits than non-frequent users. Frequent users with substance use had higher mortality at 365 days (hazard ratio [HR] 1.36 [1.04, 1.77]) and 2 years (HR 1.32 [1.04, 1.67]), but not at 90 or 30 days. Mortality did not differ for frequent users with opioid use overall. By degree, patients with substance use and > 20 visits/year and with opioid use and 16–20 visits/year demonstrated a higher 365-day and 2-year mortality.
Among patients with substance use, frequent ED use and extremely frequent use (> 20 visits/year) were associated with long-term but not short-term mortality. These findings suggest a role for targeted screening and preventive intervention.
We have measured line-strength indices as a function of radius in several elliptical galaxies. All of them show strong radial gradients in Mg, but much weaker gradients in Fe and Hβ. The isophotes and contours of constant line-strength have the same flattening. More luminous galaxies have shallower gradients, contrary to the prediction of models of dissipative collapse. Most of the galaxies observed show weak central emission which can partially fill the Balmer absorption lines.
The kinematic properties of elliptical galaxies are summarized. New developments are discussed in four areas: (i) the Faber-Jackson relation and the role of second parameters (ii) the luminosity-rotation relation (iii) the figures of elliptical galaxies and (iv) the mass-to-light ratio as a function of radius.
Motions of nearby elliptical galaxies reveal a large-scale velocity flow relative to cosmic rest towards the point 1=307±10, b = 9±10. The data are fit best by a two-component flow model. The smaller component is due to Virgo, which induces a velocity at the Local Group of 250 km/s. The main flow is due to a more massive concentration located a distance of 4350±350 km/s towards 1=307, b=9, which induces a local velocity here of 570±60 km/s. This larger component falls off away from the mass concentration roughly as r−1. The Centaurus double cluster and its neighbors are in the direction of the mass concentration but are in the foreground and are falling into it. Galaxy counts, radial velocity surveys, and the motions of nearby spirals are consistent with the above model. The IRAS dipole results are less clear but may also be consistent. There is evidence that the distant mass concentration is non-spherical, with the Centaurus cloud a substantial sub-condensation in the foreground. The formal agreement of the large-scale flow with biased (b=2) cold dark matter is low, but the simple methods used so far to assess this are uncertain. The main weakness of the present data in comparing to theory is the fact that they do not penetrate far enough to show the velocity field on all sides of the mass concentration. Sphericity and total extent of the flow are therefore still unknown.
The peculiar motions for spiral galaxies and elliptical galaxies within V = 3500 km/s are compared to the model predictions of the mass concentration (MC) velocity field model of Lynden-Bell et al. The large-scale motions defined by over 600 galaxies from three independent sets of data (Aaronson et al.; de Vaucouleurs and Peters and elliptical galaxies) are in substantial agreement with this model.
Burnout occurs among students when they suddenly lose interest in their studies due to feeling physically and emotionally drained. They experience further emotional depletion due to study demands, distrustfulness and detachment about their work. This study investigated the relationship between the Five-Factor Model (FFM) personality traits and burnout, as operationalised by Maslach's three dimensions of burnout, namely exhaustion, cynicism and reduced personal efficacy. Previous Western research was replicated in order to contribute to the cross-cultural literature on burnout. The Maslach Burnout Inventory – Student Survey University Form and the NEO – Personality Inventory Revised Form S were subjected to stepwise forward regression using FFM factors and facets to predict the scores on each burnout dimension. Five hundred and seventy-seven Filipino college students (age 17 to 24) from private universities and colleges within Metro Manila participated. Results revealed that neuroticism and conscientiousness predict all three burnout constructs. However, certain facets of neuroticism and conscientiousness are more important than others. At the facet level, facets of agreeableness and openness contributed to prediction of burnout as well.
Integrated weed management (IWM) relies upon multiple chemical, physical, or biological weed management techniques to achieve an acceptable level of weed control. Agents that selectively suppress weeds but not crops and that can be manipulated in agriculture will be promising components for inclusion in IWM. We used a meta-analytic approach to investigate the potential of arbuscular mycorrhizal fungi (AMF) to contribute to IWM. We quantified the effect of crop and weed host status (strong and weak AMF hosts are divided in this study by a 10% root length colonization threshold), AMF diversity (single vs. mixed), and soil N and P fertility management on plant mycorrhizal growth responses (MGRs). Our results indicated that weak host weeds had consistently lower MGRs than strong host crops in both controlled and field conditions. Moreover, these differences in MGRs between weak host weeds and strong host crops were more pronounced under mixed AMF inoculum and low N and P nutrient availability. In contrast, MGR of strong host weeds was not different from strong host crops in general. However, we observed a wide range of MGRs among strong host weeds, some of which had much lower MGRs than strong host crops. In addition, in the presence of N and P fertilizers, strong host crops had a stronger positive response to AMF than strong host weeds. Thus, our meta-analysis indicates that AMF have potential to contribute to weed control by direct and indirect pathways: directly suppress weak host weeds, and indirectly suppress some strong host weeds mediating by competitive effects exerted by strong host crops. We suggest that management practices affecting AMF diversity and crop and weed mycorrhizal responses could be chosen to improve the contribution of AMF to IWM. Better understanding is needed of crop–weed–AMF interactions and management practices that enhance this form of weed management.
We have used a new distance estimator for elliptical galaxies to determine the peculiar velocities, with respect to a uniform Hubble flow, of approximately 400 galaxies. The relative distances of five clusters in common with those of Aaronson et al. (1981, 1986), based on the infrared Tully-Fisher relation for spirals, are in good agreement.
We do not see the reflex of the Local Group motion with respect to the microwave background out to recession velocities of 6000 km s−1. Rather, the frame of elliptical galaxies appears to be moving with respect to the microwave background with a velocity of 600 km s−1 towards 1 = 312°, b = +6°. This motion is consistent with a re-analysis of the Rubin et al. (1976) data on the magnitude-diameter relation for ScI galaxies and with the nearby and cluster samples of Aaronson et al. (1982, 1986).
The SMAC cluster sample (Hudson et al. 1999), with a depth of ˜ 12000km s-1, has a bulk velocity of ˜ 600 km s-1, with respect to the Cosmic Microwave Background (CMB) frame. Other surveys (Willick 1999, hereafter LP10k; Lauer & Postman 1994, hereafter ACIF) have also yielded large bulk motions on similarly large scales. Taken at face value, these results appear to be in conflict with bulk flows expected from favoured cosmological models. However, at the same time, other surveys (notably Dale et al. 1999, hereafter SC) have found rather small bulk motions on large scales. We have measured bulk flows from the above mentioned surveys plus SNIa (Riess et al. 1995) in a consistent way. The results are given in Table 1. The measurement errors are due to peculiar velocity errors. Note that these are the errors typically quoted. Based on these errors alone, there appears to be conflict between some of the surveys (e.g. SC vs SMAC).
There is a growing body of evidence indicating young ages, 8 ± 3 Gyrs, for elliptical galaxies and significant age gradients with a younger population residing at the centre. The data appear to be consistent with a scenario where elliptical galaxies are assembled hierarchically with low luminosity galaxies forming first. Late star formation, associated with the last merging event and usually involving only a small fraction of the galaxy mass, could then account for the low age estimates of some luminous galaxies.
Two classes of elliptical galaxies are now recognised (Kormendy & Bender 1996). Luminous ellipticals rotate slowly (Davies et al. 1983and tend to have boxy isophotes. Ellipticals fainter than L∗ exhibit an increasing tendency to be rotationally supported and to possess a stellar disk component. This dichotomy led Bender, Burstein & Faber (1992) to suggest that the physical variable that controls the ultimate nature of a forming galaxy is the degree of gaseous dissipation that occurs in the final merger it experiences. Low luminosity systems experience more dissipative mergers which generate high rotation, disky end products. As bigger galaxies are formed, the mergers become increasingly stellar, producing the classical slow rotating ellipticals. They termed this the gas/stellar continuum. This global dichotomy is also reflected in the bimodality of core morphologies of the heterogeneous sample of local ellipticals observed with HST. The low luminosity disky galaxies have ‘hard’ cores with a steep slope in the luminosity profile at small radii, whereas the luminous galaxies have ‘soft’ cores with flat profiles at small radii (e.g. Faber et al. 1997).
Normally elliptical galaxies are thought to be old, evolved systems, but recently a controversy has arisen over the age of ellipticals. Measurements by Gonzáles (1993, Ph.D. thesis, UCSC) show that the Hβ absorption indices of ellipticals span a range of values. Population synthesis models indicate that the Hβ index is a good age indicator and hence, contrary to normal perception, the ages of ellipticals seem to span a range of values.
IAU Commission 28 (IAU C28: Galaxies) was founded in the late 1930s at which time it had only a small membership (see the historical notes by Sadler et al. 2007). When C28 ended its existence in 2015 there were well over 1000 members on its books. The membership had grown to the point where the effort to keep track of active participants had become a major task. During the C28s tenure 27 IAU Symposia have been devoted to galaxies, the third highest number (Mickaelian 2014)
Two broad aims drive weed science research: improved management and improved
understanding of weed biology and ecology. In recent years, agricultural
weed research addressing these two aims has effectively split into separate
subdisciplines despite repeated calls for greater integration. Although some
excellent work is being done, agricultural weed research has developed a
very high level of repetitiveness, a preponderance of purely descriptive
studies, and has failed to clearly articulate novel hypotheses linked to
established bodies of ecological and evolutionary theory. In contrast,
invasive plant research attracts a diverse cadre of nonweed scientists using
invasions to explore broader and more integrated biological questions
grounded in theory. We propose that although studies focused on weed
management remain vitally important, agricultural weed research would
benefit from deeper theoretical justification, a broader vision, and
increased collaboration across diverse disciplines. To initiate change in
this direction, we call for more emphasis on interdisciplinary training for
weed scientists, and for focused workshops and working groups to develop
specific areas of research and promote interactions among weed scientists
and with the wider scientific community.
KMOS is a cryogenic infrared spectrograph fed by twentyfour deployable integral field units that patrol a 7.2 arcminute diameter field of view at the Nasmyth focus of the ESO VLT. It is well suited to the study of galaxy clusters at 1 < z < 2 where the well understood features in the restframe V-band are shifted into the KMOS spectral bands. Coupled with HST imagining, KMOS offers a window on the critical epoch for galaxy evolution, 7-10 Gyrs ago, when the key properties of cluster galaxies were established. We aim to investigate the size, mass, morphology and star formation history of galaxies in the clusters. Here we describe the instrument, discuss the status of the observations and report some preliminary results.