Topo-edaphic controls over woody plant biomass in South African savannas

The distribution of woody biomass in savannas reflects spatial patterns fundamental to ecosystem processes, such as water flow, competition, and herbivory, and is a key contributor to savanna ecosystem services, such as fuelwood supply. While total precipitation sets an upper bound on savanna woody biomass, the extent to which substrate and terrain constrain trees and shrubs below this maximum remains poorly understood, often occluded by local-scale disturbances such as fire and trampling. Here we investigate the role of hillslope topography and soil properties in controlling woody plant aboveground biomass (AGB) in Kruger National Park, South Africa. Large-area sampling with airborne Light Detection and Ranging (LiDAR) provided a means to average across local-scale disturbances, revealing an unexpectedly linear relationship between AGB and hillslope-position on basalts, where biomass levels were lowest on crests, and linearly increased toward streams (<i>R</i><sup>2</sup> = 0.91). The observed pattern was different on granite substrates, where AGB exhibited a strongly non-linear relationship with hillslope position: AGB was high on crests, decreased midslope, and then increased near stream channels (<i>R</i><sup>2</sup> = 0.87). Overall, we observed 5-to-8-fold lower AGB on clayey, basalt-derived soil than on granites, and we suggest this is due to herbivore-fire interactions rather than lower hydraulic conductivity or clay shrinkage/swelling, as previously hypothesized. By mapping AGB within and outside fire and herbivore exclosures, we found that basalt-derived soils support tenfold higher AGB in the absence of fire and herbivory, suggesting high clay content alone is not a proximal limitation on AGB. Understanding how fire and herbivory contribute to AGB heterogeneity is critical to predicting future savanna carbon storage under a changing climate

Community Composition and Abundance of Bacterial, Archaeal and Nitrifying Populations in Savanna Soils on Contrasting Bedrock Material in Kruger National Park, South Africa

Savannas cover at least 13% of the global terrestrial surface and are often nutrient limited, especially by nitrogen. To gain a better understanding of their microbial diversity and the microbial nitrogen cycling in savanna soils, soil samples were collected along a granitic and a basaltic catena in Kruger National Park (South Africa) to characterize their bacterial and archaeal composition and the genetic potential for nitrification. Although the basaltic soils were on average 5 times more nutrient rich than the granitic soils, all investigated savanna soil samples showed typically low nutrient availabilities, i.e., up to 38 times lower soil N or C contents than temperate grasslands. Illumina MiSeq amplicon sequencing revealed a unique soil bacterial community dominated by Actinobacteria (20–66%), Chloroflexi (9–29%), and Firmicutes (7–42%) and an increase in the relative abundance of Actinobacteria with increasing soil nutrient content. The archaeal community reached up to 14% of the total soil microbial community and was dominated by the thaumarchaeal Soil Crenarchaeotic Group (43–99.8%), with a high fraction of sequences related to the ammonia-oxidizing genus Nitrosopshaera sp. Quantitative PCR targeting amoA genes encoding the alpha subunit of ammonia monooxygenase also revealed a high genetic potential for ammonia oxidation dominated by archaea (~5 × 107 archaeal amoA gene copies g−1 soil vs. mostly < 7 × 104 bacterial amoA gene copies g−1 soil). Abundances of archaeal 16S rRNA and amoA genes were positively correlated with soil nitrate, N and C contents. Nitrospira sp. was detected as the most abundant group of nitrite oxidizing bacteria. The specific geochemical conditions and particle transport dynamics at the granitic catena were found to affect soil microbial communities through clay and nutrient relocation along the hill slope, causing a shift to different, less diverse bacterial and archaeal communities at the footslope. Overall, our results suggest a strong effect of the savanna soils' nutrient scarcity on all microbial communities, resulting in a distinct community structure that differs markedly from nutrient-rich, temperate grasslands, along with a high relevance of archaeal ammonia oxidation in savanna soils

KINEROS2-AGWA: Model Use, Calibration, and Validation

KINEROS (KINematic runoff and EROSion) originated in the 1960s as a distributed event-based model that conceptualizes a watershed as a cascade of overland flow model elements that flow into trapezoidal channel model elements. KINEROS was one of the first widely available watershed models that interactively coupled a finite difference approximation of the kinematic overland flow equations to a physically based infiltration model. Development and improvement of KINEROS continued from the 1960s on a variety of projects for a range of purposes, which has resulted in a suite of KINEROS-based modeling tools. This article focuses on KINEROS2 (K2), a spatially distributed, event-based watershed rainfall-runoff and erosion model, and the companion ArcGIS-based Automated Geospatial Watershed Assessment (AGWA) tool. AGWA automates the time-consuming tasks of watershed delineation into distributed model elements and initial parameterization of these elements using commonly available, national GIS data layers. A variety of approaches have been used to calibrate and validate K2 successfully across a relatively broad range of applications (e.g., urbanization, pre- and post-fire, hillslope erosion, erosion from roads, runoff and recharge, and manure transport). The case studies presented in this article (1) compare lumped to stepwise calibration and validation of runoff and sediment at plot, hillslope, and small watershed scales; and (2) demonstrate an uncalibrated application to address relative change in watershed response to wildfire

Chronic Oedema and the older person: The effects of ageing upon treatment outcomes

Chronic oedema (CO) and lymphoedema (LO) are long-term conditions that can become more complicated or are more likely to develop with age. The ageing process can involve alterations in the structures that support the normal function of the lymphatic system or put it at greater risk of damage. The main three components (skin care, exercise and compression therapy) within the management of CO/LO can become more difficult to apply with age. This is because of reduced healing rates, decreased cardiovascular capacity and deterioration in vascular and arterial structures. The impact of ageing and how this can affect patients and treatment outcomes requires careful consideration

The Supreme Court and the Transformation of Juvenile Sentencing

In the past decade, the Supreme Court has transformed the constitutional landscape of juvenile crime regulation. In three strongly worded opinions, the Court held that imposing harsh criminal sentences on juvenile offenders violates the Eighth Amendment prohibition against cruel and unusual punishment. In combination, these cases create a special status for juveniles under Eighth Amendment doctrine as a category of offenders whose culpability is mitigated by their youth and immaturity, even for the most serious offenses. The Court also emphasized that juveniles are more likely to reform than adult offenders, and that most should be given a meaningful opportunity to demonstrate that they have done so. In short, because of young offenders’ developmental immaturity, harsh sentences that may be suitable for adult criminals are seldom appropriate for juveniles. These opinions announce a powerful constitutional principle – that “children are different” for purposes of criminal punishment. In articulating this principle, the Supreme Court has also provided general guidance to courts sentencing juveniles and to lawmakers charged with implementing the rulings. At the same time, the Court did not directly address the specifics of implementation and it left many questions unanswered about the implications of the opinions for juvenile sentencing regulation. In the years since Roper, Graham, and Miller, courts and legislatures have struggled to interpret the opinions and to create procedures and policies that are compatible with constitutional principles and doctrine. This report addresses the key issues facing courts and legislatures under this new constitutional regime, and provides guidance based on the Supreme Court’s Eighth Amendment analysis and on the principles the Court has articulated. Part I begins with the constitutional sentencing framework, grounded in the opinions and embodying the key elements of the Court’s analysis. It then explains the underlying developmental knowledge that supports the constitutional framework and the “children are different” principle. Part II Part II examines how courts and legislatures have responded to the Eighth Amendment opinions, through reforms of state laws regulating juvenile life without parole (JLWOP). While some state lawmakers appear to ignore or subvert the Supreme Court’s holdings, others have responded in ways that clearly embody the principles underlying Miller and Graham. In Montgomery v. Louisiana, the Court held that Miller applies retroactively because it established a substantive rule of constitutional law. Part III translates Miller’s directive that specific factors be considered in making individualized sentencing decisions. The report\u27s aim is to guide courts and clinicians in structuring sentencing hearings that incorporate sound developmental research and other evidence supporting or negating mitigation, without going beyond the limits of science. Part IV explores the broader implications of the Supreme Court’s developmental framework for juvenile sentencing and parole, implications that have already sparked law reforms beyond the relatively narrow holdings of Graham and Miller. Finally, the paper ends on a cautionary note, pointing to evidence that constitutionally sound, developmentally-based policies may be vulnerable to political and other pressures. Aside from mandates in the holdings themselves, reforms can be dismantled or discounted if conditions change. Measures to sustain the current trend in law reform are discussed

Exploring haemodynamics of haemodialysis using extrema points analysis model

Background: Haemodialysis is a form of renal replacement therapy used to treat patients with end stage renal failure. It is becoming more appreciated that haemodialysis patients exhibit higher rates of multiple end organ damage compared to the general population. There is also a strong emerging evidence that haemodialysis itself causes circulatory stress. We aimed at examining haemodynamic patterns during haemodialysis using a new model and test that model against a normal control. Methods: We hypothesised that blood pressures generated by each heart beat constantly vary between local peaks and troughs (local extrema), the frequency and amplitude of which is regulated to maintain optimal organ perfusion. We also hypothesised that such model could reveal multiple haemodynamic aberrations during HD. Using a non-invasive cardiac output monitoring device (Finometer®) we compared various haemodynamic parameters using the above model between a haemodialysis patient during a dialysis session and an exercised normal control after comparison at rest. Results: Measurements yielded 29,751 data points for each haemodynamic parameter. Extrema points frequency of mean arterial blood pressure was higher in the HD subject compared to the normal control (0.761Hz IQR 0.5-0.818 vs 0.468Hz IQR 0.223-0.872, P < 0.0001). Similarly, extrema points frequency of systolic blood pressure was significantly higher in haemodialysis compared to normal. In contrary, the frequency of extrema points for TPR was higher in the normal control compared to HD (0.947 IQR 0.520-1.512 vs 0.845 IQR 0.730-1.569, P < 0.0001) with significantly higher amplitudes. Conclusion: Haemodialysis patients potentially exhibit an aberrant haemodynamic behaviour characterised by higher extrema frequencies of mean arterial blood pressure and lower extrema frequencies of total peripheral resistance. This, in theory, could lead to higher variation in organ perfusion and may be detrimental to vulnerable vascular beds

Mãe, cadê o bebê? Repercussões do nascimento prematuro de um irmão

O objetivo deste artigo foi investigar as repercussões do nascimento prematuro do bebê sobre o(s) seu(s) irmão(s), sob a perspectiva materna, durante a internação do recém-nascido na Unidade de Terapia Intensiva Neonatal. O estudo contou com a participação de 37 mães, entrevistadas no 15º dia após o parto. Elas responderam a instrumentos que contemplaram dados demográficos familiares, informações clínicas do bebê e da mãe, e a experiência da maternidade no contexto da prematuridade. A entrevista sobre maternidade continha questões acerca do irmão do bebê, cujas respostas foram examinadas a partir de análise de conteúdo qualitativa. Os resultados revelaram alteração na rotina dos irmãos em razão da maior ausência materna. Os sentimentos e reações dos irmãos incluíram questionamentos, preocupações, ciúme e ansiedade, ao lado de contentamento e curiosidade. A visita do irmão ao bebê prematuro não foi permitida por alguns hospitais. Evidencia-se a importância de os irmãos serem atendidos em suas necessidades de cuidado nesse período de hospitalização do bebê

Institutional Response to Crisis

The Institutional Response to Crisis panel focuses on analyzing and understanding institutions and the crises they might face, more specifically the limits and opportunities for preparing for a crisis, responding to crises, and the long-term consequences of crises. The panelists provide both theoretical analyses and specific, personal experiences to discuss these points. As panel moderator Noah Pickus, the director of the Kenan Institute for Ethics at Duke University stated in his opening: Crises are no rare thing in human history and it seems as if of late we turn around everyday and there\u27s another one that stares us in the face. Questions/themes/discussion topics Should institutions respond to crises? How do institutions respond to crises? Response to crisis as a springboard for long term change within an institution Leadership opportunities within a crisi

Rapid response of habitat structure and above-ground carbon storage to altered fire regimes in tropical savanna

Fire regimes across the globe have been altered through changes in land use, land management, and climate conditions. Understanding how these modified fire regimes impact vegetation structure and dynamics is essential for informed biodiversity conservation and carbon management in savanna ecosystems. We used a fire experiment at the Territory Wildlife Park (TWP), northern Australia, to investigate the consequences of altered fire regimes for vertical habitat structure and above-ground carbon storage. We mapped vegetation three-dimensional (3-D) structure in high spatial resolution with airborne lidar across 18 replicated 1&thinsp;ha plots of varying fire frequency and season treatments. We used lidar-derived canopy height and cover metrics to extrapolate field-based measures of woody biomass to the full extent of the experimental site (R2=0.82, RMSE&thinsp;=&thinsp;7.35&thinsp;t&thinsp;C&thinsp;ha−1) and analysed differences in above-ground carbon storage and canopy structure among treatments. Woody canopy cover and biomass were highest in the absence of fire (76&thinsp;% and 39.8&thinsp;t&thinsp;C&thinsp;ha−1) and lowest in plots burnt late in the dry season on a biennial basis (42&thinsp;% and 18.2&thinsp;t&thinsp;C&thinsp;ha−1). Woody canopy vertical profiles differed among all six fire treatments, with the greatest divergence in height classes &lt;5&thinsp;m. The magnitude of fire effects on vegetation structure varied along the environmental gradient underpinning the experiment, with less reduction in biomass in plots with deeper soils. Our results highlight the large extent to which fire management can shape woody structural patterns in savanna landscapes, even over time frames as short as a decade. The structural profile changes shown here, and the quantification of carbon reduction under late dry season burning, have important implications for habitat conservation, carbon sequestration, and emission reduction initiatives in the region.</p