Increased life span in a polyphenic butterfly artificially selected for starvation resistance

Starvation resistance is closely associated with fitness in natural populations of many organisms. It often co-varies with longevity and is a relevant target for understanding the evolution of aging. We selected for increased starvation resistance in the seasonally polyphenic butterfly Bicyclus anynana in a warm, wet-seasonal environment over 17 generations. We measured the response to selection for two selected lines compared to that of an unselected stock. Results show an increase in survival under adult starvation of 50%-100%. In addition, selection lines showed an increase in life span under normal adult feeding of 30%-50%. Female reproduction was changed toward laying fewer but larger eggs. The results indicate a sex-specific response to selection: females reallocated resources toward a more durable body, whereas males appeared to increase starvation resistance through changed metabolic rate. The phenotype produced by artificial selection resembles the form that occurs in the cool, dry-season environment, which suggests that selection has targeted the regulatory mechanisms for survival that are also involved in the suite of traits (including starvation resistance) central to the adaptive plastic response of this butterfly to seasonal conditions. In general, these results imply that the regulation of life span involves mechanisms of phenotypic plasticity.     

The consequences of uncertainties in land use, climate and vegetation responses on the terrestrial carbon

The IPCC SRES narratives were implemented in IMAGE 2.2 to evaluate thefuture condition of the climate system (including the biosphere). A series of scenario experiments was used to assess possible ranges in emissions and concentrations of greenhouse gases, climate change and impacts. These experiments focussed on the role of the terrestrial carbon cycle. The experiments show that the SRES narratives dominate human emissions and not natural processes. In contrary, atmospheric CO2 concentration strongly differs between the experiments. Atmospheric CO2 concentrations range for A1B from 714 to 1009 ppmv CO2 in 2100. The spread of this range is comparable with the full SRES range as implemented in IMAGE 2.2 (515-895 μmol/mol CO2). The most important negative and positive feedback processes in IMAGE 2.2 on the build-up of CO2 concentrations are CO2 fertilisation and soil respiration respectively. Indirect effects of these processes furtherchange land-use patterns, deforestation rates and alter the natural C fluxes. The cumulative effects of these changes have a pronounced influence on the final CO2 concentrations. Our scenario experiments highlight the importance of a proper parameterisation of feedback processes, C-cycle and land use in determining the future states of the climate system.     

Vasoplegia after implantation of a continuous flow left ventricular assist device: incidence,outcomes and predictors

Background

Vasoplegia after routine cardiac surgery is associated with severe postoperative complications and increased mortality. It is also prevalent in patients undergoing implantation of pulsatile flow left ventricular assist devices (LVAD). However, less is known regarding vasoplegia after implantation of newer generations of continuous flow LVADs (cfLVAD). We aim to report the incidence, impact on outcome and predictors of vasoplegia in these patients.

Methods

Adult patients scheduled for primary cfLVAD implantation were enrolled into a derivation cohort (n?=?118, 2006–2013) and a temporal validation cohort (n?=?73, 2014–2016). Vasoplegia was defined taking into consideration low mean arterial pressure and/or low systemic vascular resistance, preserved cardiac index and high vasopressor support. Vasoplegia was considered after bypass and the first 48?h of ICU stay lasting at least three consecutive hours. This concept of vasoplegia was compared to older definitions reported in the literature in terms of the incidence of postoperative vasoplegia and its association with adverse outcomes. Logistic regression was used to identify independent predictors. Their ability to discriminate patients with vasoplegia was quantified by the area under the receiver operating characteristic curve (AUC).

Results

The incidence of vasoplegia was 33.1% using the unified definition of vasoplegia. Vasoplegia was associated with increased ICU length-of-stay (10.5 [6.9–20.8] vs 6.1 [4.6–10.4] p?=?0.002), increased ICU-mortality (OR 5.8, 95% CI 1.9–18.2) and one-year-mortality (OR 3.9, 95% CI 1.5–10.2), and a higher incidence of renal failure (OR 4.3, 95% CI 1.8–10.4). Multivariable analysis identified previous cardiothoracic surgery, preoperative dopamine administration, preoperative bilirubin levels and preoperative creatinine clearance as independent preoperative predictors of vasoplegia. The resultant prediction model exhibited a good discriminative ability (AUC 0.80, 95% CI 0.71–0.89, p?<? 0.01). Temporal validation resulted in an AUC of 0.74 (95% CI 0.61–0.87, p?<? 0.01).

Conclusions

In the era of the new generation of cfLVADs, vasoplegia remains a prevalent (33%) and critical condition with worse short-term outcomes and survival. We identified previous cardiothoracic surgery, preoperative treatment with dopamine, preoperative bilirubin levels and preoperative creatinine clearance as independent predictors.

     

Shellfish Reefs Increase Water Storage Capacity on Intertidal Flats Over Extensive Spatial Scales

Ecosystem engineering species can affect their environment at multiple spatial scales, from the local scale up to a significant distance, by indirectly affecting the surrounding habitats. Structural changes in the landscape can have important consequences for ecosystem functioning, for example, by increasing retention of limiting resources in the system. Yet, it remains poorly understood how extensive the footprint of ecosystem engineers on the landscape is. Using remote sensing techniques, we reveal that depression storage capacity on intertidal flats is greatly enhanced by engineering by shellfish resulting in intertidal pools. Many organisms use such pools to bridge low water events. This storage capacity was significantly higher both locally within the shellfish reef, but also at extensive spatial scales up to 115 m beyond the physical reef borders. Therefore, the footprint of these ecosystem engineers on the landscape was more than 5 times larger than their actual coverage; the shellfish cover approximately 2% of the total intertidal zone, whereas they influence up to approximately 11% of the area by enhancing water storage capacity. We postulate that increased residence time of water due to higher water storage capacity within engineered landscapes is an important determinant of ecosystem functioning that may extend well beyond the case of shellfish reefs provided here.     

Human plasma protein <Emphasis Type="Italic">N</Emphasis>-glycosylation

Glycosylation is the most abundant and complex protein modification, and can have a profound structural and functional effect on the conjugate. The oligosaccharide fraction is recognized to be involved in multiple biological processes, and to affect proteins physical properties, and has consequentially been labeled a critical quality attribute of biopharmaceuticals. Additionally, due to recent advances in analytical methods and analysis software, glycosylation is targeted in the search for disease biomarkers for early diagnosis and patient stratification. Biofluids such as saliva, serum or plasma are of great use in this regard, as they are easily accessible and can provide relevant glycosylation information. Thus, as the assessment of protein glycosylation is becoming a major element in clinical and biopharmaceutical research, this review aims to convey the current state of knowledge on the N-glycosylation of the major plasma glycoproteins alpha-1-acid glycoprotein, alpha-1-antitrypsin, alpha-1B-glycoprotein, alpha-2-HS-glycoprotein, alpha-2-macroglobulin, antithrombin-III, apolipoprotein B-100, apolipoprotein D, apolipoprotein F, beta-2-glycoprotein 1, ceruloplasmin, fibrinogen, immunoglobulin (Ig) A, IgG, IgM, haptoglobin, hemopexin, histidine-rich glycoprotein, kininogen-1, serotransferrin, vitronectin, and zinc-alpha-2-glycoprotein. In addition, the less abundant immunoglobulins D and E are included because of their major relevance in immunology and biopharmaceutical research. Where available, the glycosylation is described in a site-specific manner. In the discussion, we put the glycosylation of individual proteins into perspective and speculate how the individual proteins may contribute to a total plasma N-glycosylation profile determined at the released glycan level.