1,230 research outputs found
Recreating Pastoralist Futures
Research experience in southern Africa is used to reflect on key determinants of pastoral futures and how they might need to be addressed. The paper begins with a brief review of what we mean by marginality. A set of observations on key issues defining the option sets for pastoralism in the future is then presented. The first of these is that only a small number of structures or processes actually control the behaviour of social-ecological systems such as pastoralist systems. A second observation is that the future is so uncertain that there is a need to learn to design for robustness across plausible futures. Coupled to this is the observation that a reliable understanding of how we might manage adaptive capacity in pastoral people and communities is needed. Lastly it is suggested that a vital frontier in research is the set of relationships between cognition, emotions and behaviour at the scales of the individual and society
The Properties of Brightest Cluster Galaxies in X-Ray Selected Clusters
We present the K-band Hubble diagram for 162 brightest cluster galaxies
(BCGs) in X-ray selected clusters, 0.01<z<0.83. The sample incorporates that of
Burke, Collins, & Mann (2000) and includes additional infrared data from the
2MASS extended source catalogue. We show that below z=0.1 the BCGs show no
correlation with their environment, however, above z=0.1 BCGs in more X-ray
luminous clusters are more uniform in their photometric properties. This
suggests that there may be two populations of BCGs which have different
evolutionary histories.Comment: 2 pages, to appear in the proceedings of the Sesto 2001 conference on
tracing cosmic evolution with galaxy cluster
Gold-alkynyls in catalysis : Alkyne activation, gold cumulenes and nuclearity
The use of cationic gold(i) species in the activation of substrates containing CC bonds has become a valuable tool for synthetic chemists. Despite the seemingly simple label of 'alkyne activation', numerous patterns of reactivity and product structure are observed in systems employing related substrates and catalysts. The complications of mechanistic determination are compounded as the number of implicated gold(i) centres involved in catalysis increases and debate about the bonding in proposed intermediates clouds the number and importance of potential reaction pathways. This perspective aims to illustrate some of the principles underpinning gold-alkynyl interactions whilst highlighting some of the contentious areas in the field and offering some insight into other, often ignored, mechanistic possibilities based on recent findings
Cross-Lagged Relations Between Motives and Substance Use: Can Use Strengthen Your Motivation Over Time?
Motives for substance use have garnered considerable attention due to the strong predictive utility of this construct, both in terms of use and problems associated with use. The current study examined the cross-lagged relations between alcohol use and motives, and marijuana use and motives over three yearly assessment periods in a large sample (N = 526, 48% male) of college students. The relations between substance use and motives were assessed at each time point, allowing for the examination of these inter-relations over time. Results indicated different trends based on the type of substance. For alcohol use, cross-lagged trends were found between freshman and sophomore year for coping, social, and conformity motives with cross-lagged relations between enhancement motives and alcohol use across all years. However, outside of enhancement motives, cross-lagged relations were not found between sophomore and junior year. In contrast, cross-lagged effects were found for marijuana use and coping, enhancement, and expansion motives between sophomore and junior year, but not freshman year. These results suggest that people’s expectations that drinking or smoking marijuana makes activities more reinforcing and helps them cope with distress may perpetuate use. In turn, use itself may enhance these expectations over time. Results have direct implications for treatment, with recommended focus on motives, behavior activation, and healthy coping skills in order to interrupt the cycle of substance use
Bendamustine combined with rituximab for patients with relapsed or refractory diffuse large B cell lymphoma
Patients with relapsed or refractory diffuse large B cell lymphoma (DLBCL) are treated with salvage regimens and may be considered for high-dose chemotherapy and autologous stem cell transplantation if disease is chemosensitive. Bendamustine is active in indolent B cell lymphomas and chronic lymphocytic leukemia but has not been extensively studied in aggressive lymphomas. This trial examines the combination of bendamustine and rituximab in patients with relapsed and refractory DLBCL. Patients received bendamustine at 90 mg/m2 (n = 2) or 120 mg/m2 (n = 57) on days 1 and 2 and rituximab at 375 mg/m2 on day 1 every 28 days for up to 6 cycles. The study evaluated objective response rate (ORR), duration of response (DOR), progression-free survival (PFS), and treatment safety. Fifty-nine patients were treated, and 48 were evaluable for response. Median age was 74; 89 % had stage III or IV disease, and 63 % had high revised International Prognostic Index scores; the median number of prior therapies was 1. Based on analysis using the intent-to-treat population, the ORR was 45.8 % (complete response, 15.3 %; partial response, 30.5 %). The median DOR was 17.3 months, and the median PFS was 3.6 months. Grade 3 or 4 hematological toxicities included neutropenia (36 %), leukopenia (29 %), thrombocytopenia (22 %), and anemia (12 %). The combination of bendamustine and rituximab showed modest activity in patients with relapsed and refractory DLBCL and has an acceptable toxicity profile
Road induced edge effects on a forest bird community in tropical Asia
Background: Edge effects cause changes in bird community richness, abundance, and/or distribution within a landscape, but the avian guilds most influenced can vary among regions. Although Southeast Asia has the highest rates of deforestation and projected species loss, and is currently undergoing an explosive growth in road infrastructure, there have been few studies of the effects of forest edges on avian communities in this region.
Methods: We examined avian community structure in a dry evergreen forest in northeastern Thailand adjacent to a five-lane highway. We evaluated the richness and abundance of birds in 11 guilds at 24 survey points on three parallel transects perpendicular to the edge. At each point, 10-min surveys were conducted during February‒August 2014 and March‒August 2015. Vegetation measurements were conducted at 16 of the bird survey points and ambient noise was measured at all 24 survey points.
Results: We found a strongly negative response to the forest edge for bark-gleaning, sallying, terrestrial, and understory insectivores and a weakly negative response for arboreal frugivore-insectivores, foliage gleaning insectivores, and raptors. Densities of trees and the percentage canopy cover were higher in the interior, and the ambient noise was lower. In contrast, arboreal nectarivore-insectivores responded positively to the forest edge, where there was a higher vegetation cover in the ground layer, a lower tree density, and a higher level of ambient noise.
Conclusion: Planners should avoid road development in forests of high conservation value to reduce impacts on biodiversity. Where avoidance is impossible, a number of potential mitigation methods are available, but more detailed assessments of these are needed before they are applied in this region
Interpersonal and affective dimensions of psychopathic traits in adolescents : development and validation of a self-report instrument
We report the development and psychometric evaluations of a self-report instrument designed to screen for psychopathic traits among mainstream community adolescents. Tests of item functioning were initially conducted with 26 adolescents. In a second study the new instrument was administered to 150 high school adolescents, 73 of who had school records of suspension for antisocial behavior. Exploratory factor analysis yielded a 4-factor structure (Impulsivity α = .73, Self-Centredness α = .70, Callous-Unemotional α = .69, and Manipulativeness α = .83). In a third study involving 328 high school adolescents, 130 with records of suspension for antisocial behaviour, competing measurement models were evaluated using confirmatory factor analysis. The superiority of a first-order model represented by four correlated factors that was invariant across gender and age was confirmed. The findings provide researchers and clinicians with a psychometrically strong, self-report instrument and a greater understanding of psychopathic traits in mainstream adolescents
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