84 research outputs found
The Western Australian regional forest agreement: economic rationalism and the normalisation of political closure
This article explores the constraints imposed by economic rationalism on environmental policy-making in light of Western Australia\u27s (WA) Regional Forest Agreement (RFA) experience. Data derived from interviews with WA RFA stakeholders shed light on their perceptions of the RFA process and its outcomes. The extent to which involvement of science and the public RFA management enabled is analysed. The findings point to a pervasive constrainedness of WA\u27s RFA owing to a closing of the process by the administrative decision-making structures. A dominant economic rationality is seen to have normalised and legitimised political closure, effectively excluding rationalities dissenting from an implicit economic orthodoxy. This article argues for the explication of invisible, economic constraints affecting environmental policy and for the public-cum-political negotiation of the points of closure within political processes
Parent of origin genetic effects on methylation in humans are common and influence complex trait variation
Parent-of-origin effects (POE) are observed when there are different effects from alleles inherited from the two parents on phenotypic measures. Here, Zeng et al. study POE on DNA methylation in 5,101 individuals and identify genetic variants that associate with methylation variation via POE and their potential phenotypic consequences
Amyloid Plaques Beyond Aβ: A Survey of the Diverse Modulators of Amyloid Aggregation
Aggregation of the amyloid-β (Aβ) peptide is strongly correlated with Alzheimer’s disease (AD). Recent research has improved our understanding of the kinetics of amyloid fibril assembly and revealed new details regarding different stages in plaque formation. Presently, interest is turning toward studying this process in a holistic context, focusing on cellular components which interact with the Aβ peptide at various junctures during aggregation, from monomer to cross-β amyloid fibrils. However, even in isolation, a multitude of factors including protein purity, pH, salt content, and agitation affect Aβ fibril formation and deposition, often producing complicated and conflicting results. The failure of numerous inhibitors in clinical trials for AD suggests that a detailed examination of the complex interactions that occur during plaque formation, including binding of carbohydrates, lipids, nucleic acids, and metal ions, is important for understanding the diversity of manifestations of the disease. Unraveling how a variety of key macromolecular modulators interact with the Aβ peptide and change its aggregation properties may provide opportunities for developing therapies. Since no protein acts in isolation, the interplay of these diverse molecules may differentiate disease onset, progression, and severity, and thus are worth careful consideration
Assessing ecological resilience to human induced environmental change in shallow lakes
Sudden unpredictable changes in ecosystems are an increasing source of concern because of
their inherent unpredictability and the difficulties involved in restoration. Our understanding
of the changes that occur across different trophic levels and the form of this change is lacking.
This is especially true of large shallow lakes, where characteristics such as fetch and depth
are close to theoretical boundary values for hysteretic behaviour. The development of
reliable indicators capable of predicting these changes has been the focus of much research
in recent years. The success of these early warning indicators (EWIs) has so far been mixed.
There remain many unknowns about how they perform under a wide variety of conditions
and parameters. Future climate change is predicted to have a wide range of impacts through
the interaction of combined pressures, making the understanding of EWIs and the in-lake
processes that occur during regime shifts imperative. Loch Leven, Scotland, UK, is a large
shallow lake with a history of eutrophication, research and management and as such is an
ideal study site to better understand resilience and regime shifts under a range of interacting
stressors.
The objectives of this research are to: (1) analyse long term data to identify the occurrence
of common tipping points within the chemical (water column nutrient concentrations) and
biological (macrophytes, phytoplankton, zooplankton) components of the loch, then test
these tipping points using five statistical early warning indicators (EWIs) across multiple
rolling window sizes; and (2) quantify the changes in lake ecology using a before/after
analysis and testing for non-linearity, combined with modelling using the aquatic ecosystem
process model PCLake to determine the level of resilience following a regime shift during
recovery from eutrophication; (3) using PCLake, examine the sensitivity of Loch Leven to
regime shifts in the face of predicted environmental change (e.g. climate change, nutrient
pollution).
Statistical analysis identified tipping points across all trophic levels included, from physical
and chemical variables through to apex predators. The success of EWIs in predicting the
tipping points was highly dependent on the number of EWIs used, with window size having
a smaller impact. The 45% window size had the highest overall accuracy across all EWIs but
only detected 16.5% more tipping points than the window size with the lowest overall
accuracy. Differences between individual EWI performance and usage of them as a group
was substantial with a 29.7% increase between the two. In both individual and group use of
EWIs, false positives (early warning without a tipping point) were more common than true
positives (tipping point preceded by EWI), creating significant doubts about their reliability
as management tools.
Significant change was seen across multiple variables and trophic levels in the before/after
analysis following sudden recovery from eutrophication, with most variables also showing
evidence of non-linear change. Modelling of responses to nutrient loading for chlorophyll,
zooplankton and macrophytes, under states from before and after the shift, indicate
hysteresis and thus the presence of feedback mechanisms. The modelling of responses to
nutrient loading and predicted climate change in temperature and precipitation
demonstrated that increases in temperature and decreases in summer precipitation
individually had large impacts on chlorophyll and zooplankton at medium to high phosphorus
(P) loads. However, modelling of the combined effects of these changes resulted in the
highest lake chlorophyll concentrations of all tested scenarios. At low P loads higher
temperatures and increased winter precipitation had the greatest impact on system
resilience with a lower Critical Nutrient Load (CNL). The difference between chlorophyll and
zooplankton as opposed to macrophytes was in the presence of a lower CNL for the increased
winter precipitation-only scenarios which was not seen in the macrophytes. This highlights
the potential role of high winter inputs potentially loaded with particulate matter in reducing
resilience at lower P loads.
This research has highlighted the vulnerability and low resilience of Loch Leven to
environmental change. The presence of multiple tipping points and high levels of EWI activity
show a high level of flexibility in the system. Coupled with the occurrence of widespread
trophic change during a sudden recovery and a small level of hysteresis and high levels of
sensitivity to climate change, the low levels of resilience become clear. The impact of lake-specific
characteristics such as moderate depth, large fetch and a heterogeneous bed
morphology is particularly evident in the limitations on macrophyte cover and the reliance
on zooplankton to determine the hysteresis offset (amount of phosphorus (P) loading
between the two CNL). The presence of these characteristics can be used to identify other
lakes vulnerable to change. Improving the predictive capabilities of resilience indicators such
as EWIs, and better understanding of the ecological changes that occur during non-linear
change in response to recovery and climate change, can help target relevant ecosystem
components for preventative management. These actions may become necessary under
even the most conservative estimates of environmental change
Reviewing the use of resilience concepts in forest sciences
Purpose of the review Resilience is a key concept to deal with an uncertain future in forestry. In recent years, it has received increasing attention from both research and practice. However, a common understanding of what resilience means in a forestry context, and how to operationalise it is lacking. Here, we conducted a systematic review of the recent forest science literature on resilience in the forestry context, synthesising how resilience is defined and assessed.
Recent findings Based on a detailed review of 255 studies, we analysed how the concepts of engineering resilience, ecological resilience, and social-ecological resilience are used in forest sciences. A clear majority of the studies applied the concept of engineering resilience, quantifying resilience as the recovery time after a disturbance. The two most used indicators for engineering resilience were basal area increment and vegetation cover, whereas ecological
resilience studies frequently focus on vegetation cover and tree density. In contrast, important social-ecological resilience indicators used in the literature are socio-economic diversity and stock of natural resources. In the context of global change, we expected an increase in studies adopting the more holistic social-ecological resilience concept, but this was not the observed trend. Summary Our analysis points to the nestedness of these three resilience concepts, suggesting that they are complementary rather than contradictory. It also means that the variety of resilience approaches does not need to be an obstacle for operationalisation of the concept. We provide guidance for choosing the most suitable resilience concept and indicators based on the management, disturbance and application context
Lactation and cardiovascular risk factors in mothers in a population-based study: the HUNT-study
<p>Abstract</p> <p>Background</p> <p>Lactation has beneficial short term effects on maternal metabolic health, but the long term effects are less well known.</p> <p>Methods</p> <p>We studied the association between lifetime duration of lactation and cardiovascular risk factors in mothers later in life among 21,368 parous women aged 20 to 85 years attending the second Nord-Trøndelag Health Study (HUNT2) in 1995–1997, Norway, a cross-sectional population-based study. General linear modelling was used to calculate mean values of known cardiovascular risk factor levels in five categories of lifetime duration of lactation. Logistic regression was conducted to estimate odds ratios of hypertension, obesity and diabetes.</p> <p>Results</p> <p>Among women aged 50 years or younger, lifetime duration of lactation was significantly and inversely associated with body mass index (<it>P</it>-trend, < 0.001), waist circumference (<it>P</it>-trend, < 0.001), systolic and diastolic blood pressure (both <it>P</it>-trends, < 0.001), and serum levels of triglycerides, total cholesterol and low density lipoprotein cholesterol (all <it>P</it>-trends, < 0.001) after adjustment for covariates. Parous women aged 50 years or younger who had never lactated had higher prevalence of hypertension, obesity and diabetes. In this age group, compared to women who had lactated for 24 months or more, parous women who had never lactated had an OR for hypertension of 1.88 (95% CI 1.41, 2.51), an OR for obesity of 3.37 (95% CI 2.51, 4.51) and an OR for diabetes of 5.87 (95% CI 2.25, 15.3). Among women older than 50 years there were no clear associations.</p> <p>Conclusion</p> <p>Lifetime duration of lactation was associated with long term reduced cardiovascular risk levels in mothers aged 50 years or younger.</p
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