| 21. |
- Komatsu, Kimberly J., et al.
(författare)
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Global change effects on plant communities are magnified by time and the number of global change factors imposed
- 2019
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 116:36, s. 17867-17873
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Tidskriftsartikel (refereegranskat)abstract
- Accurate prediction of community responses to global change drivers (GCDs) is critical given the effects of biodiversity on ecosystem services. There is consensus that human activities are driving species extinctions at the global scale, but debate remains over whether GCDs are systematically altering local communities worldwide. Across 105 experiments that included over 400 experimental manipulations, we found evidence for a lagged response of herbaceous plant communities to GCDs caused by shifts in the identities and relative abundances of species, often without a corresponding difference in species richness. These results provide evidence that community responses are pervasive across a wide variety of GCDs on long-term temporal scales and that these responses increase in strength when multiple GCDs are simultaneously imposed.Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (<10 y). In contrast, long-term (≥10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity–ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously.
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| 22. |
- Lippert, Marcus, 1974-
(författare)
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Communities in the Digital Age : Towards a Theoretical Model of Communities of Practice and Information Technology
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The global change towards a knowledge economy forces organizations to seek new and better ways to manage knowledge work and learning. Organizations have recognized that dfferent information technologies can play an important role in their quest to make the desired changes take place. Along with this increasing interest in information technologies we have also noticed a growing interest in a specific type of community, referred to as communities of practice (CoP). A considerable body of research that studies communities of practice in relation to IT continues to grow. Despite this we are far from a theoretical model of the relation between communities of practice and IT that may guide future research and understanding in a fruitful way.The basis for this thesis are the lack of a theoretical model to describe a dialectical relation between communities of practice and information technologies and how these relations come into being. The purpose of this thesis and research study is to contribute to existing theories of communities of practice by developing a theoretical model of a dialectical relation between information technology and communities of practice. In line with this, the study addresses the following research question How do a community of practice and information technology constitute and shape each other? Furthermore, the research study adheres to an interpretative philosophy, a qualitative research design, and longitudinal research case study conducted at Siemens Sweden.This research study was divided in two parts. Part One presented the theoretical chapters and a theoretical working model, referred to as the CoPIT model (Community of Practice model of Information Technology). In Part Two the initial CoPIT model was confronted with empirical data and used to analyze and illustrate the relation between CoP and IT. The main conclusion drawn from the research study is that the CoPIT model makes sense and is relevant, and also that the general principles upon which it is founded hold true. Furthermore, from the empirical confrontation of the CoPIT model we can draw the conclusion that relations exist both between IT in general and the CoP component’s specific constructs and between CoP in general and the IT component’s specific constructs. These key findings validate the point of departure of this study that there is a dialectical relation between CoP and IT, and that they mutually constitute each other over time.
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| 23. |
- Mathias, Andrew, et al.
(författare)
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Prognostic implications of mutation-specific QTc standard deviation in congenital long QT syndrome
- 2013
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Ingår i: Heart Rhythm. - : Elsevier BV. - 1547-5271. ; 10:5, s. 720-725
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Individual corrected QT interval (QTc) may vary widely among carriers of the same long QT syndrome (LOTS) mutation. Currently, neither the mechanism nor the implications of this variable penetrance are well understood. OBJECTIVES To hypothesize that the assessment of QTc variance in patients with congenital LOTS who carry the same mutation provides incremental prognostic information on the patient-specific QTc. METHODS The study population comprised 1206 patients with LOTS with 95 different mutations and >= 5 individuals who carry the same mutation. Multivariate Cox proportional hazards regression analysis was used to assess the effect of mutation-specific standard deviation of QTc (QTcSD) on the risk of cardiac events (comprising syncope, aborted cardiac arrest, and sudden cardiac death) from birth through age 40 years in the total population and by genotype. RESULTS Assessment of mutation-specific QTcSD showed large differences among carriers of the same mutations (median QTcSD 45 ms). Multivariate analysis showed that each 20 ms increment in QTcSD was associated with a significant 33% (P=.002) increase in the risk of cardiac events after adjustment for the patient-specific QTc duration and the family effect on QTc. The risk associated with QTcSD was pronounced among patients with long QT syndrome type 1 (hazard ratio 1.55 per 20 ms increment; P<.001), whereas among patients with long QT syndrome type 2, the risk associated with QTcSD was not statistically significant (hazard ratio 0.99; P=.95; P value for QTcSD-by-genotype interaction=.002). CONCLUSIONS Our findings suggest that mutations with a wider variation in QTc duration are associated with increased risk of cardiac events. These findings appear to be genotype-specific, with a pronounced effect among patients with the long QT syndrome type 1 genotype.
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| 24. |
- Migdalovich, Dimitry, et al.
(författare)
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Mutation and gender-specific risk in type 2 long QT syndrome: Implications for risk stratification for life-threatening cardiac events in patients with long QT syndrome
- 2011
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Ingår i: Heart Rhythm. - : Elsevier BV. - 1547-5271. ; 8:10, s. 1537-1543
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Men and women with type 2 long QT syndrome (LQT2) exhibit time-dependent differences in the risk for cardiac events. We hypothesized that data regarding the location of the disease-causing mutation in the KCNH2 channel may affect gender-specific risk in LQT2. OBJECTIVE This study sought to risk-stratify LQT2 patients for life-threatening cardiac events based on clinical and genetic information. METHODS The risk for life-threatening cardiac events from birth through age 40 years (comprising aborted cardiac arrest [ACA] or sudden cardiac death [SCD]) was assessed among 1,166 LQT2 male (n = 490) and female (n = 676) patients by the location of the LQTS-causing mutation in the KCNH2 channel (prespecified in the primary analysis as pore-loop vs. non-pore-loop). RESULTS During follow-up, the cumulative probability of life-threatening cardiac events years was significantly higher among LQT2 women (26%) as compared with men (14%; P <.001). Multivariate analysis showed that the risk for life-threatening cardiac events was not significantly different between women with and without pore-loop mutations (hazard ratio 1.20; P = .33). In contrast, men with pore-loop mutations displayed a significant > 2-fold higher risk of a first ACA or SCD as compared with those with non-pore-loop mutations (hazard ratio 2.18; P = .01). Consistently, women experienced a high rate of life-threatening events regardless of mutation location (pore-loop: 35%, nonpore-loop: 23%), whereas in men the rate of ACA or SCD was high among those with pore-loop mutations (28%) and relatively low among those with non-pore-loop mutations (8%). CONCLUSION Combined assessment of clinical and mutation-specific data can be used for improved risk stratification for life-threatening cardiac events in LQT2.
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| 25. |
- Miles, Elizabeth A, et al.
(författare)
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The Salmon in Pregnancy Study : study design, subject characteristics, maternal fish and marine n-3 fatty acid intake, and marine n-3 fatty acid status in maternal and umbilical cord blood
- 2011
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Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 94:6, s. 1986S-1992S
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Oily fish provides marine n-3 (omega-3) fatty acids that are considered to be important in the growth, development, and health of the fetus and newborn infant. OBJECTIVES: The objectives were to increase salmon consumption among pregnant women and to determine the effect on maternal and umbilical cord plasma marine n-3 fatty acid content. DESIGN: Women (n = 123) with low habitual consumption of oily fish were randomly assigned to continue their habitual diet or were provided with 2 portions of farmed salmon/wk to include in their diet from week 20 of pregnancy until delivery. RESULTS: Median weekly consumption frequency of study salmon in the salmon group was 1.94 portions, and total fish consumption frequency was 2.11 portions/wk in the salmon group and 0.47 portions/wk in the control group (P < 0.001). Intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from the diet, from seafood, and from oily fish were higher in the salmon group (all P < 0.001). Percentages of EPA and DHA in plasma phosphatidylcholine decreased during pregnancy in the control group (P for trend = 0.029 and 0.008, respectively), whereas they increased in the salmon group (P for trend for both < 0.001). EPA and DHA percentages were higher in maternal plasma phosphatidylcholine at weeks 34 and 38 of pregnancy and in umbilical cord plasma phosphatidylcholine in the salmon group (P < 0.001 for all). CONCLUSION: If pregnant women, who do not regularly eat oily fish, eat 2 portions of salmon/wk, they will increase their intake of EPA and DHA, achieving the recommended minimum intake; and they will increase their and their fetus' status of EPA and DHA. This trial was registered at clinicaltrials.gov as NCT00801502.
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| 26. |
- Morel, Alexandra C., et al.
(författare)
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Carbon dynamics, net primary productivity and human-appropriated net primary productivity across a forest–cocoa farm landscape in West Africa
- 2019
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 25:8, s. 2661-2677
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Tidskriftsartikel (refereegranskat)abstract
- Terrestrial net primary productivity (NPP) is an important metric of ecosystem functioning; however, there are little empirical data on the NPP of human-modified ecosystems, particularly smallholder, perennial crops like cocoa (Theobroma cacao), which are extensive across the tropics. Human-appropriated NPP (HANPP) is a measure of the proportion of a natural system's NPP that has either been reduced through land-use change or harvested directly and, previously, has been calculated to estimate the scale of the human impact on the biosphere. Additionally, human modification can create shifts in NPP allocation and decomposition, with concomitant impacts on the carbon cycle. This study presents the results of 3 years of intensive monitoring of forest and smallholder cocoa farms across disturbance, management intensity, distance from forest and farm age gradients. We measured among the highest reported NPP values in tropical forest, 17.57 ± 2.1 and 17.7 ± 1.6 Mg C ha−1 year−1 for intact and logged forest, respectively; however, the average NPP of cocoa farms was still higher, 18.8 ± 2.5 Mg C ha−1 year−1, which we found was driven by cocoa pod production. We found a dramatic shift in litterfall residence times, where cocoa leaves decomposed more slowly than forest leaves and shade tree litterfall decomposed considerably faster, indicating significant changes in rates of nutrient cycling. The average HANPP value for all cocoa farms was 2.1 ± 1.1 Mg C ha−1 year−1; however, depending on the density of shade trees, it ranged from −4.6 to 5.2 Mg C ha−1 year−1. Therefore, rather than being related to cocoa yield, HANPP was reduced by maintaining higher shade levels. Across our monitored farms, 18.9% of farm NPP was harvested (i.e., whole cocoa pods) and only 1.1% (i.e., cocoa beans) was removed from the system, suggesting that the scale of HANPP in smallholder cocoa agroforestry systems is relatively small.
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| 27. |
- Morel, Alexandra C., et al.
(författare)
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Landscape and management influences on smallholder agroforestry yields show shifts during a climate shock
- 2024
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Ingår i: Agriculture, Ecosystems and Environment. - 0167-8809. ; 366
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Tidskriftsartikel (refereegranskat)abstract
- Sustaining yields for smallholder perennial agriculture under a rapidly changing climate regime may require consideration of landscape features and on-farm management decisions in tandem. Optimising landscape and management may not be possible for maximising yields in any one year but maintaining heterogeneous landscapes could be an important climate adaptation strategy. In this study, we observed elevation, forest patch and shade management gradients affecting smallholder coffee (Coffea arabica) yields in a ‘normal’ year versus the 2015/16 El Niño. We generally found a benefit to yields from having leguminous shade trees and low canopy openness, while maintaining diverse shade or varying canopy openness had more complex influences during a climate shock. The two years of observed climate shock were dominated by either drought or high temperatures, with yield responses generally negative. Climate projections for East Africa predict more erratic rainfall and higher temperatures, which will disproportionately impact smallholder farmers.
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| 28. |
- Morel, Alexandra C., et al.
(författare)
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The Ecological Limits of Poverty Alleviation in an African Forest-Agriculture Landscape
- 2019
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Ingår i: Frontiers in Sustainable Food Systems. - : Frontiers Media SA. - 2571-581X. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Cocoa yields in Ghana remain low. This has variously been attributed to low rates of fertilizer application, pollinator limitation, and particularly dry growing conditions. In this paper we use an African forest-agriculture landscape dominated by cocoa (Theobroma cacao) to develop an ecological production function, allowing us to identify key ecological and management limits acting on cocoa yields simultaneously. These included more consistent application of fertilizers inter-annually, distributing rotting biomass throughout the farm and reducing the incidence of capsid attacks. By relaxing these limits, we estimate plausible increases in yields and, by extension, farm incomes. Our analysis reveals that resulting increases in cocoa yields requiring both ecological and intensive management interventions could be significant (113 ± 60%); however, benefits are disproportionately realized by the wealthiest households. We found that wealthier households benefited proportionally more from ecological intensification methods (e.g., leaving more rotting biomass in their farms) and the poorest households benefited proportionally more from capital-intensive intensification methods (e.g., pesticide and fertilizer applications). We treated poverty as multi-dimensional, and show that only certain dimensions of poverty (school attendance, assets, and food security) are significantly related to cocoa incomes, while several other dimensions (access to clean water, sanitation and electricity, and infant mortality) are not. We explore how increased household cocoa incomes could impact different dimensions of poverty. Our findings suggest, that if all households adopted the optimal level of each of these management options, and in so doing had similar poverty profiles to those households already managing optimally, we would see the community-averaged probability: a child of a household misses school decrease from 47 to 31%, a household would be able to acquire assets increase from 40 to 59% and a household would have access to an adequate amount of food increase from 62 to 79%.
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| 29. |
- Morel, Alexandra C., et al.
(författare)
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The structures underpinning vulnerability : Examining landscape-society interactions in a smallholder coffee agroforestry system
- 2019
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 14:7
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Tidskriftsartikel (refereegranskat)abstract
- Smallholder farmers dependent on rain-fed agriculture are particularly vulnerable to extreme climate events and, therefore, it is necessary to identify adaptive measures that would increase farmer resilience to these shocks. The management options in a low-input system, like forest coffee (Coffea arabica), are limited and there are several factors out of farmers' control driving their vulnerability to changing climatic conditions. These can relate to social structures and landscape factors, which can interact to reduce farmers' adaptive capacity, creating a state of contextual vulnerability. We explored the potential synergies of this interaction across elevation, patch area and shade management gradients for smallholder coffee farms around the UNESCO Yayu Coffee Forest Biosphere Reserve in Ethiopia before, during and immediately following the 2015/16 El Niño. We documented a dramatic collapse in coffee yields across all farms, resulting in coffee incomes 29.5% ±18.0% and 19.5% ±10.0% of 2014 incomes in 2015 and 2016, respectively. We identified farms at elevations between 1500 and 1600 m with canopy openness between 40% and 45% as being consistently low yielding over our study period. We found these farmers had the highest rates of income diversification and, therefore, were already exhibiting adaptive capacity. Farmers with the largest income losses were spatially concentrated between 1600 and 1700 m, located in larger patch areas with lower canopy openness. Farmers at this elevation have access to poor infrastructure, restrictions on shade management and reported higher dependence on income from coffee, indicating an interaction of biotic and social factors exacerbating their vulnerability. Unfortunately, due to a nationally declared state of emergency, we were unable to survey farmers on the adaptive measures they undertook; therefore, we are limited in assessing their resilience. However, we do show the importance of considering both biotically and socially-mediated influences for assessing smallholder vulnerability, particularly barriers to diversifying incomes.
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| 30. |
- Mowbray, Carol T, et al.
(författare)
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Consumer Drop-in Centers : Operations, Services, and Consumer Involvement
- 2002
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Ingår i: Health & Social Work. - : National Association of Social Workers. - 0360-7283 .- 1545-6854. ; 27:4, s. 248-261
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Tidskriftsartikel (refereegranskat)abstract
- Interest in involvement of consumers in mental health and psychiatric rehabilitation services delivery has expanded in recent years, encompassing self-help approaches, consumers employed as providers in formal agencies, and consumers operating their own services. This study reports results from in-depth phone surveys conducted with 32 consumer drop-in centers in Michigan. Results indicate that centers operate in many ways like other human services businesses, albeit with much smaller budgets. Funding levels, salaries, and services showed great heterogeneity among the centers and in comparison with reports in the literature. Centers autonomously run by consumers and centers with consumer involvement (operated by a non-consumer agency) were found to differ significantly on several variables, including consumer control, funding and service levels, and challenges. Implications for the growth and increased use of consumer drop-in centers are discussed.
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