Landscape constraints on mire lateral expansion

Little is known about the long-term expansion of mire ecosystems, despite their importance in the globalcarbon and hydrogeochemical cycles. It has been firmly established that mires do not expand linearlyover time. Despite this, mires are often assumed to have expanded at a constant rate after initiationsimply for lack of a better understanding. There has not yet been a serious attempt to determine the rateand drivers of mire expansion at the regional, or larger spatial scales. Here we make use of a naturalchronosequence, spanning the Holocene, which is provided by the retreating coastline of NorthernSweden. By studying an isostatic rebound area we can infer mire expansion dynamics by looking at theportion of the landscape where mires become progressively scarce as the land becomes younger. Ourresults confirms that mires expanded non-linearly across the landscape and that their expansion isrelated to the availability of suitably wet areas, which, in our case, depends primarily on the hydro-edaphic properties of the landscape. Importantly, we found that mires occupied the wettest locationsin the landscape within only one to two thousand years, while it took mires three to four thousand yearsto expand into slightly drier areas. Our results imply that the lateral expansion of mires, and thus peataccumulation is a non-linear process, occurring at different rates depending, above all else, on thewetness of the landscape

Cortisol levels and suicidal behavior: a meta-analysis

Suicide is a major cause of death worldwide, responsible for 1.5% of all mortality. The causes of suicidal behavior are not fully understood. Dysregulated hypothalamic-pituitary-adrenal (HPA) axis activity, as measured by cortisol levels, is one potential risk factor. This meta-analytic review aimed i) to estimate the strength and variability of the association between naturally fluctuating cortisol levels and suicidal behavior and ii) to identify moderators of this relationship. A systematic literature search identified 27 studies (N = 2226; 779 suicide attempters & 1447 non-attempters) that met the study eligibility criteria from a total of 417 unique records initially examined. Estimates of effect sizes (r) obtained from these studies were analysed using Comprehensive Meta-Analysis. In these analyses, we compared participants identified as having a past history of suicide attempt(s) to those with no such history. Study quality, mean age of sample and percentage of male participants were examined as potential moderators. Overall, there was no significant effect of suicide group on cortisol. However, significant associations between cortisol and suicide attempts were observed as a function of age. In studies where the mean age of the sample was below 40 years the association was positive (i.e., higher cortisol was associated with suicide attempts; r = .234, p < .001), and where the mean age was 40 or above the association was negative (i.e., lower cortisol was associated with suicide attempts; r = - .129, p < .001). These findings confirm that HPA axis activity, as indicated by age-dependent variations in cortisol levels, is associated with suicidal behavior. The challenge for theory and clinical practice is to explain the complete reversal of the association with age and to identify its clinical implications

Cognition, behaviour and academic skills after cognitive rehabilitation in Ugandan children surviving severe malaria: a randomised trial

<p>Abstract</p> <p>Background</p> <p>Infection with severe malaria in African children is associated with not only a high mortality but also a high risk of cognitive deficits. There is evidence that interventions done a few years after the illness are effective but nothing is known about those done immediately after the illness. We designed a study in which children who had suffered from severe malaria three months earlier were enrolled into a cognitive intervention program and assessed for the immediate benefit in cognitive, academic and behavioral outcomes.</p> <p>Methods</p> <p>This parallel group randomised study was carried out in Kampala City, Uganda between February 2008 and October 2010. Sixty-one Ugandan children aged 5 to 12 years with severe malaria were assessed for cognition (using the Kaufman Assessment Battery for Children, second edition and the Test of Variables of Attention), academic skills (Wide Range Achievement Test, third edition) and psychopathologic behaviour (Child Behaviour Checklist) three months after an episode of severe malaria. Twenty-eight were randomised to sixteen sessions of computerised cognitive rehabilitation training lasting eight weeks and 33 to a non-treatment group. Post-intervention assessments were done a month after conclusion of the intervention. Analysis of covariance was used to detect any differences between the two groups after post-intervention assessment, adjusting for age, sex, weight for age z score, quality of the home environment, time between admission and post-intervention testing and pre-intervention score. The primary outcome was improvement in attention scores for the intervention group. This trial is registered with Current Controlled Trials, number ISRCTN53183087.</p> <p>Results</p> <p>Significant intervention effects were observed in the intervention group for learning mean score (SE), [93.89 (4.00) vs 106.38 (4.32), <it>P </it>= 0.04] but for working memory the intervention group performed poorly [27.42 (0.66) vs 25.34 (0.73), <it>P </it>= 0.04]. No effect was observed in the other cognitive outcomes or in any of the academic or behavioural measures.</p> <p>Conclusions</p> <p>In this pilot study, our computerised cognitive training program three months after severe malaria had an immediate effect on cognitive outcomes but did not affect academic skills or behaviour. Larger trials with follow-up after a few years are needed to investigate whether the observed benefits are sustained.</p> <p>Trial registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN53183087">ISRCTN53183087</a></p

Adaptation of the multidimensional scale of perceived social support in a Ugandan setting

Background: The Multidimensional Scale of Perceived Social Support (MSPSS) was developed in the USA. The adequacy of its use in Uganda to guarantee its reliability and validity has not been ascertained.Aim: Thus the aim of the present study was to adapt the MSPSS scale by testing the validity and reliability of the scale in a Ugandan setting.Methods: A cross-sectional design was employed and 240 respondents were consecutively recruited from postnatal clinics in Mulago hospital. Analysis of reliability and validity of the adapted MSPSS was done. Cronbach alpha and principal component analyses were respectively generated.Results: Three subscales of the MSPSS that had been identified in other populations were evident in the Ugandan population. Using the Cronbach’s alpha, the MSPSS demonstrated good internal consistency at .83. A dendrogram indicated that all sub items of the MSPSS were inter-linked. Exploratory Factor analysis derived three components. Principal Component analysis using rotated varimax generated high loadings on all subscales.Conclusion: The adapted MSPSS can reliably be used in Uganda.Key Words: Multidimensional Scale of Perceived social support, (MSPSS), adaptation, social support, validity, reliabilityAfrican Health Sciences 2009; 9(S): 35-4

Topography and time shape mire morphometry and large-scale mire distribution patterns in the northern boreal landscape

Peatlands are major terrestrial soil carbon stores, and open mires in boreal landscapes hold a considerable fraction of the global peat carbon. Despite decades of study, large-scale spatiotemporal analyses of mire arrangement have been scarce, which has limited our ability to scale-up mire properties, such as carbon accumulation to the landscape level. Here, we use a land-uplift mire chronosequence in northern Sweden spanning 9,000 years to quantify controls on mire distribution patterns. Our objectives include assessing changes in the spatial arrangement of mires with land surface age, and understanding modifications by upland hydrotopography. Characterizing over 3,000 mires along a 30 km transect, we found that the time since land emergence from the sea was the dominant control over mire coverage, especially for the establishment of large mire complexes. Mires at the youngest end of the chronosequence were small with heterogenous morphometry (shape, slope, and catchment-to-mire areal ratios), while mires on the oldest surfaces were variable in size, but included larger mires with more complex shapes and smaller catchment-to-mire ratios. In general, complex topography fragmented mires by constraining the lateral expansion, resulting in a greater number of mires, but reduced total mire area regardless of landscape age. Mires in this study area occurred on slopes up to 4%, indicating a hydrological boundary to peatland expansion under local climatic conditions. The consistency in mire responses to spatiotemporal controls illustrates how temporal limitation in peat initiation and accumulation, and topographic constraints to mire expansion together have shaped present day mire distribution patterns

A preliminary examination of the construct validity of the KABC-II in Ugandan children with a history of cerebral malaria

Background: Several diseases and adverse conditions affect the cognitive development of children in Sub-Saharan African. There is need to assess these children to determine which abilities are affected and the severity of the damage so as to plan interventions accordingly. However most psychological tests developed in the West have not been validated in this region making it impossible to know whether they measure what they were intended to in African children. Objective: To examine the construct validity of the Kaufman Assessment Battery for Children, Second Edition (KABC-II) in Ugandan children. Methods: Sixty five Ugandan children aged 7 to 16 years (Mean=9.90, SD=2.46) were tested using the KABC-II 44.59 months (SD=2.82) after an episode of cerebral malaria. The KABC-II scales of Sequential Processing, Simultaneous Processing, Planning and Learning were administered. In order to identify which factors result from administering the KABC-II in these children, factor analysis using principal component analysis with Varimax rotation was applied to the subtests making up the above scales. Results: Five factors emerged after factor analysis comprising of subtests measuring Sequential Processing, Simultaneous Processing, Planning and Learning. The fifth scale comprised of subtests measuring immediate and delayed recall. Conclusion: This preliminary study in Ugandan children shows the KABC-II to have good construct validity with subtests measuring similar abilities loading on the same factor. The KABC-II can be used in assessing Ugandan children after a few modifications. Further analysis of its psychometric properties in Ugandan children is required

Landscape constraints on mire lateral expansion

Little is known about the long-term expansion of mire ecosystems, despite their importance in the global carbon and hydrogeochemical cycles. It has been firmly established that mires do not expand linearly over time. Despite this, mires are often assumed to have expanded at a constant rate after initiation simply for lack of a better understanding. There has not yet been a serious attempt to determine the rate and drivers of mire expansion at the regional, or larger spatial scales. Here we make use of a natural chronosequence, spanning the Holocene, which is provided by the retreating coastline of Northern Sweden. By studying an isostatic rebound area we can infer mire expansion dynamics by looking at the portion of the landscape where mires become progressively scarce as the land becomes younger. Our results confirms that mires expanded non-linearly across the landscape and that their expansion is related to the availability of suitably wet areas, which, in our case, depends primarily on the hydro-edaphic properties of the landscape. Importantly, we found that mires occupied the wettest locations in the landscape within only one to two thousand years, while it took mires three to four thousand years to expand into slightly drier areas. Our results imply that the lateral expansion of mires, and thus peat accumulation is a non-linear process, occurring at different rates depending, above all else, on the wetness of the landscape

Time geography : a model for psychiatric life charting?

Since many years, life charting has been used to describe the life course and life events ofpsychiatric patients. The aim of the present study was to describe and evaluate timegeographic life charts of 11 former psychiatric patients in order to promote systematicdescriptions of their life events over time. Information on all events which was gatheredfrom the life charts was analysed by manifest content analysis and reduced to four categories:information received by asking only about moves, social capacity, predisposing lifeevents and/or stressful as well as precipitating life events. Our findings showed that this kindof life charts offered a comprehensive and structured picture. They describe a detailed lifesituation from one time period to another, where geographical sites serve as anchors. Thepatients expressed satisfaction with this method of combining an interview with a timegeographic life line