Drought tolerance and implications for vegetation-climate interactions in the Amazon forest

2012 Spring.Includes bibliographical references.On seasonal and annual timescales, the Amazon forest is resistant to drought, but more severe droughts can have profound effects on ecosystem productivity and tree mortality. The majority of climate models predict decreased rainfall in tropical South America over this century. Until recently, land surface models have not included mechanisms of forest resistance to seasonal drought. In some coupled climate models, the inability of tropical forest to withstand warming and drying leads to replacement of forest by savanna by 2050. The main questions of this research are: What factors affect forest drought tolerance, and what are the implications of drought tolerance mechanisms for climate? Forest adaptations to drought, such as development of deep roots, enable Amazon forests to withstand seasonal droughts, and the maintenance of transpiration during dry periods can affect regional climate. At high levels of water stress, such as those imposed during a multiyear rainfall exclusion experiment or during interannual drought, trees prevent water loss by closing their stomata. We examine forest response to drought in an ecosystem model (SiB3 - the Simple Biosphere model) compared to two rainfall exclusion experiments in the Amazon. SiB3 best reproduces the observed drought response using realistic soil parameters and annual LAI, and by adjusting soil depth. SiB3's optimal soil depth at each site serves as a proxy for forest drought resistance. Based on the results at the exclusion sites, we form the hypothesis that forests with periodic dry conditions are more adapted to drought. We parameterize stress resistance as a function of precipitation climatology, soil texture, and percent forest cover. The parameterization impacts carbon and moisture fluxes during extreme drought events. The loss of productivity is of similar magnitude as plot-based measurements of biomass loss during the 2005 drought. Changing stress resistance in SiB3 also affects surface evapotranspiration during dry periods, which has the potential to affect climate through changing sensible and latent heat fluxes. We examine the effects of forest stress resistance on climate through coupled experiments of SiB3 in a GCM. In a single column model, we find evidence for a more active hydrologic cycle due to increased stress resistance. The boundary layer responds through changes in its depth, relative humidity, and turbulent kinetic energy, and the changes feed back to influence wet season onset and intensity. In a full global GCM, increased stress resistance often decreases drought intensity through enhanced ET and changes to circulation. The circulation responds to changes in atmospheric latent heating and can affect precipitation in the South Atlantic Convergence Zone

The utility of scoring systems in critically ill cirrhotic patients admitted to a general intensive care unit

Purpose: This study aimed to establish which prognostic scoring tool provides the greatest discriminative ability when assessing critically ill cirrhotic patients in a general intensive care unit (ICU) setting.<p></p> Methods: This was a 12-month, single-centered prospective cohort study performed in a general, nontransplant ICU. Forty clinical and demographic variables were collected on admission to calculate 8 prospective scoring tools. Patients were followed up to obtain ICU and inhospital mortality. Receiver operating characteristic curve analysis was used to determine the discriminative ability of the scores. Univariate and multivariate analyses were used to identify any independent predictors of mortality in these patients. The incorporation of any significant variables into the scoring tools was assessed.<p></p> Results: Fifty-nine cirrhotic patients were admitted over the study period, with an ICU mortality of 31%. All scores other than the renal-specific Acute Kidney Injury Network score had similar discriminative abilities, producing area under the curves of between 0.70 and 0.76. None reached the clinically applicable level of 0.8. The Sequential Organ Failure Assessment score was the best performing score. Lactate and ascites were individual predictors of ICU mortality with statistically significant odds ratios of 1.69 and 5.91, respectively. When lactate was incorporated into the Child-Pugh score, its prognostic accuracy increased to a clinically applicable level (area under the curve, 0.86).<p></p> Conclusions: This investigation suggests that established prognostic scoring systems should be used with caution when applied to the general, nontransplant ICU as compared to specialist centers. Our data suggest that serum arterial lactate may improve the prognostic ability of these scores

A survey of women's experiences of using period tracker applications: Attitudes, ovulation prediction and how the accuracy of the app in predicting period start dates affects their feelings and behaviours

INTRODUCTION: Using an online survey, the aim of this study was to ask women about their real-life experiences of using period tracker apps, their attitudes towards using their app, the information the app provided regarding ovulation and how the accuracy of the app in predicting period start dates affects their feelings and behaviours if their period comes earlier or later than predicted. METHODS: This mixed-methods observational study was conducted by an online survey of 50 multiple-choice and open-ended questions. The survey was generated with Qualtrics XM® and promoted via social media. It was open to any person who had used a period tracker. RESULTS: From 375 total responses, 330 complete responses were obtained, giving a completion rate of 88.0%. Respondents were aged between 14 and 54, with a mean age of 26.0 (±7.81). When asked what was the best thing about using the app, 29.7% (98/330) of respondents selected 'To know when I'm ovulating'. Respondents were asked if their period ever started earlier than the app predicted; 54.9% (189/330) said it had and 72.1% (238/330) said it had started later than predicted. When asked how they felt if their period arrived earlier or later than expected, thematic analysis of periods starting earlier revealed four themes: feeling unaffected, being frustrated/unprepared, feeling anxious/stressed and feeling confused/intrigued. Thematic analysis when their period arrived later revealed six themes: anxious/concerned about pregnancy, disappointed about pregnancy, seeking advice/informing healthcare professionals, thoughts about menopause, feeling unaffected and being better prepared. CONCLUSION: Period trackers need to be clearer on their intended use and reliability, especially for period due date and ovulation. Qualitative analysis shows the impact of inaccurate predictions on aspects of the users' health. This study calls for period tracker app companies to update their apps to provide transparency to their users about their intended use and capabilities

JULES-BE:Representation of bioenergy crops and harvesting in the Joint UK Land Environment Simulator vn5.1

We describe developments to the land surface model JULES, allowing for flexible user-prescribed harvest regimes of various perennial bioenergy crops or natural vegetation types. Our aim is to integrate the most useful aspects of dedicated bioenergy models into dynamic global vegetation models, in order that assessment of bioenergy options can benefit from state-of-the-art Earth system modelling. A new plant functional type (PFT) representing Miscanthus is also presented. The Miscanthus PFT fits well with growth parameters observed at a site in Lincolnshire, UK; however, global observed yields of Miscanthus are far more variable than is captured by the model, primarily owing to the model's lack of representation of crop age and establishment time. Global expansion of bioenergy crop areas under a 2 ?C emissions scenario and balanced greenhouse gas mitigation strategy from the IMAGE integrated assessment model (RCP2.6- SSP2) achieves a mean yield of 4.3 billion tonnes of dry matter per year over 2040-2099, around 30 % higher than the biomass availability projected by IMAGE. In addition to perennial grasses, JULES-BE can also be used to represent short-rotation coppicing, residue harvesting from cropland or forestry and rotation forestry

A vision for reinvigorating global mental health

Across individuals, communities, and ecosystems, unequal ways of living mean different experiences and expressions of wellbeing and distress. What would it mean for Global Mental Health (GMH) to start with these disparities in lived-experience, radically, rather than take them as stumbling blocks to unite under a broad GMH umbrella? This question builds on a tradition of critically appraising the GMH field (see e.g. [1]), seeking a re-shaping of GMH around a shared vision deeply rooted in relationality, equity, and care

Conducting Research with Tribal Communities: Sovereignty, Ethics, and Data-Sharing Issues

When conducting research with American Indian tribes, informed consent beyond conventional Institutional Review Board (IRB) review is needed because there may be potential for adverse consequences at a community or governmental level that are unrecognized by academic researchers. This paper reviews sovereignty, research ethics, and data-sharing considerations when doing community-based participatory health-related or natural resource-related research with American Indian nations and presents a model material and data-sharing agreement that meets tribal and university requirements. Only tribal nations themselves can identify potential adverse outcomes, and they can do this only if they understand the assumptions and methods of the proposed research. Tribes much be truly equal partners in study design, data collection, interpretation, and publication. Advances in protection of intellectual property rights are also applicable to IRB reviews, as are principles of sovereignty and indigenous rights, all of which affect data ownership and control. Academic researchers engaged in tribal projects should become familiar with all three areas: sovereignty, ethics and informed consent, and intellectual property rights (IPR). We recommend developing an agreement with tribal partners that reflects both health-related IRB and natural resource-related IPR considerations

Anatomical differences in three wing muscles of the Grey heron (Ardea cinerea), the Common buzzard (Buteo buteo) and the Common kestrel (Falco tinnunculus): a possible functional interpretation

In this paper, a description of the coracobrachialis caudalis, the scapulotriceps and the extensor carpi radialis muscles is presented in three different species (Common kestrel, Common buzzard and Grey heron) that exhibit notably differing flight styles. The primary goal of this research is to describe the gross anatomy of species not previously examined. Secondly, we attempt to advance a functional interpretation of the structures studied, to understand if such noticeable differences in flight style could have induced a differentiation in the above mentioned wing muscles. Regarding the coracobrachialis caudalis muscle, the Grey heron exhibited an unusual conformation with two \u201creversed\u201d heads and a great amount of fibrous bundles. Moreover, the \u201canchors\u201d of the scapulotriceps muscle were well developed in the Grey heron and vestigial in the Common kestrel, while an intermediate situation was observed in the Common buzzard. In addition, the extensor carpi radialis muscle showed interesting findings concerning the number of heads and their disposition. Our data may corroborate some previously advanced functional interpretation. In particular, the structure of the coracobrachialis muscle is in line with the hypothesis of its role as muscular strut. Moreover, the humeral and scapular anchors could play a role in increasing the scapulotriceps tension during some phases of the beat cycle or it may be involved in maintaining wing posture. Regarding the different number of heads and the disposition of the extensor carpi radialis muscle, we believe that it could play a role in maintaining the wing position. Although a correct functional interpretation can be obtained only through multidisciplinary studies, we believe that an in-depth gross anatomy study should always be conducted beforehand, to serve as basis for further and more specific research

Evaluation of JULES-crop performance against site observations of irrigated maize from Mead, Nebraska

We use the results to point to future priorities for model development and describe how our methodology can be adapted to set up model runs for other sites and crop varietie