Projecting terrestrial biodiversity intactness with GLOBIO 4

Scenario‐based biodiversity modelling is a powerful approach to evaluate how possible future socio‐economic developments may affect biodiversity. Here, we evaluated the changes in terrestrial biodiversity intactness, expressed by the mean species abundance (MSA) metric, resulting from three of the shared socio‐economic pathways (SSPs) combined with different levels of climate change (according to representative concentration pathways [RCPs]): a future oriented towards sustainability (SSP1xRCP2.6), a future determined by a politically divided world (SSP3xRCP6.0) and a future with continued global dependency on fossil fuels (SSP5xRCP8.5). To this end, we first updated the GLOBIO model, which now runs at a spatial resolution of 10 arc‐seconds (~300 m), contains new modules for downscaling land use and for quantifying impacts of hunting in the tropics, and updated modules to quantify impacts of climate change, land use, habitat fragmentation and nitrogen pollution. We then used the updated model to project terrestrial biodiversity intactness from 2015 to 2050 as a function of land use and climate changes corresponding with the selected scenarios. We estimated a global area‐weighted mean MSA of 0.56 for 2015. Biodiversity intactness declined in all three scenarios, yet the decline was smaller in the sustainability scenario (?0.02) than the regional rivalry and fossil‐fuelled development scenarios (?0.06 and ?0.05 respectively). We further found considerable variation in projected biodiversity change among different world regions, with large future losses particularly for sub‐Saharan Africa. In some scenario‐region combinations, we projected future biodiversity recovery due to reduced demands for agricultural land, yet this recovery was counteracted by increased impacts of other pressures (notably climate change and road disturbance). Effective measures to halt or reverse the decline of terrestrial biodiversity should not only reduce land demand (e.g. by increasing agricultural productivity and dietary changes) but also focus on reducing or mitigating the impacts of other pressures.     

Mortality and Life Expectancy in Homeless Men and Women in Rotterdam: 2001–2010

Background

Data on mortality among homeless people are limited. Therefore, this study aimed to describe mortality patterns within a cohort of homeless adults in Rotterdam (the Netherlands) and to assess excess mortality as compared to the general population in that city.

Methods

Based on 10-year follow-up of homeless adults aged ≥ 20 years who visited services for homeless people in Rotterdam in 2001, and on vital statistics, we assessed the association of mortality with age, sex and type of service used (e.g. only day care, convalescence care, other) within the homeless cohort, and also compared mortality between the homeless and general population using Poisson regression. Life tables and decomposition methods were used to examine differences in life expectancy.

Results

During follow-up, of the 2096 adult homeless 265 died. Among the homeless, at age 30 years no significant sex differences were found in overall mortality rates and life expectancy. Compared with the general Rotterdam population, mortality rates were 3.5 times higher in the homeless cohort. Excess mortality was larger in women (rate ratio [RR] RR 5.56, 95% CI 3.95–7.82) as compared to men (RR 3.31, 95% CI 2.91–3.77), and decreased with age (RR 7.67, 95% CI 6.87–8.56 for the age group 20–44 and RR 1.63, 95% CI 1.41–1.88 for the age group 60+ years). Life expectancy at age 30 years was 11.0 (95% CI 9.1–12.9) and 15.9 (95% CI 10.3–21.5) years lower for homeless men and women compared to men and women in the general population respectively.

Conclusion

Homeless adults face excessive losses in life expectancy, with greatest disadvantages among homeless women and the younger age groups.     

The role of light-harvesting complex I in excitation energy transfer from LHCII to photosystem I in Arabidopsis

Photosynthesis powers nearly all life on Earth. Light absorbed by photosystems drives the conversion of water and carbon dioxide into sugars. In plants, photosystem I (PSI) and photosystem II (PSII) work in series to drive the electron transport from water to NADP⁺. As both photosystems largely work in series, a balanced excitation pressure is required for optimal photosynthetic performance. Both photosystems are composed of a core and light-harvesting complexes (LHCI) for PSI and LHCII for PSII. When the light conditions favor the excitation of one photosystem over the other, a mobile pool of trimeric LHCII moves between both photosystems thus tuning their antenna cross-section in a process called state transitions. When PSII is overexcited multiple LHCIIs can associate with PSI. A trimeric LHCII binds to PSI at the PsaH/L/O site to form a well-characterized PSI–LHCI–LHCII supercomplex. The binding site(s) of the “additional” LHCII is still unclear, although a mediating role for LHCI has been proposed. In this work, we measured the PSI antenna size and trapping kinetics of photosynthetic membranes from Arabidopsis (Arabidopsis thaliana) plants. Membranes from wild-type (WT) plants were compared to those of the ΔLhca mutant that completely lacks the LHCI antenna. The results showed that “additional” LHCII complexes can transfer energy directly to the PSI core in the absence of LHCI. However, the transfer is about two times faster and therefore more efficient, when LHCI is present. This suggests LHCI mediates excitation energy transfer from loosely bound LHCII to PSI in WT plants.

The light-harvesting antennae of photosystem I facilitate energy transfer from trimeric light-harvesting complex II to photosystem I in the stroma lamellae membrane.     

Protective antiviral immune responses to pseudorabies virus induced by DNA vaccination using dimethyldioctadecylammonium bromide as an adjuvant

To enhance the efficacy of a DNA vaccine against pseudorabies virus (PRV), we evaluated the adjuvant properties of plasmids coding for gamma interferon or interleukin-12, of CpG immunostimulatory motifs, and of the conventional adjuvants dimethyldioctadecylammonium bromide in water (DDA) and sulfolipo-cyclodextrin in squalene in water. We demonstrate that a DNA vaccine combined with DDA, but not with the other adjuvants, induced significantly stronger immune responses than plasmid vaccination alone. Moreover, pigs vaccinated in the presence of DDA were protected against clinical disease and shed significantly less PRV after challenge infection. This is the first study to demonstrate that DDA, a conventional adjuvant, enhances DNA vaccine-induced antiviral immunity.     

The role of dendritic cells in the pathogenesis of systemic lupus erythematosus

The etiology of the autoimmune disease systemic lupus erythematosus is not known, but aberrant apoptosis and/or insufficient clearance of apoptotic material have been assigned a pivotal role. During apoptosis, nucleosomes and several endogenous danger-associated molecular patterns are incorporated in blebs. Recent data indicate that apoptotic blebs induce maturation of myeloid dendritic cells, resulting in IL-17 production by T cells. In this review we summarize current knowledge on the role of dendritic cells in the pathogenesis of systemic lupus erythematosus with special emphasis on the uptake of apoptotic blebs by dendritic cells, and the subsequent induction of Th17 cells.     

Modelling multi-pulse population dynamics from ultrafast spectroscopy

Current advanced laser, optics and electronics technology allows sensitive recording of molecular dynamics, from single resonance to multi-colour and multi-pulse experiments. Extracting the occurring (bio-) physical relevant pathways via global analysis of experimental data requires a systematic investigation of connectivity schemes. Here we present a Matlab-based toolbox for this purpose. The toolbox has a graphical user interface which facilitates the application of different reaction models to the data to generate the coupled differential equations. Any time-dependent dataset can be analysed to extract time-independent correlations of the observables by using gradient or direct search methods. Specific capabilities (i.e. chirp and instrument response function) for the analysis of ultrafast pump-probe spectroscopic data are included. The inclusion of an extra pulse that interacts with a transient phase can help to disentangle complex interdependent pathways. The modelling of pathways is therefore extended by new theory (which is included in the toolbox) that describes the finite bleach (orientation) effect of single and multiple intense polarised femtosecond pulses on an ensemble of randomly oriented particles in the presence of population decay. For instance, the generally assumed flat-top multimode beam profile is adapted to a more realistic Gaussian shape, exposing the need for several corrections for accurate anisotropy measurements. In addition, the (selective) excitation (photoselection) and anisotropy of populations that interact with single or multiple intense polarised laser pulses is demonstrated as function of power density and beam profile. Using example values of real world experiments it is calculated to what extent this effectively orients the ensemble of particles. Finally, the implementation includes the interaction with multiple pulses in addition to depth averaging in optically dense samples. In summary, we show that mathematical modelling is essential to model and resolve the details of physical behaviour of populations in ultrafast spectroscopy such as pump-probe, pump-dump-probe and pump-repump-probe experiments.     

Techno-economic evaluation of an inclusion body solubilization and recombinant protein refolding process

Expression of recombinant proteins in Escherichia coli is normally accompanied by the formation of inclusion bodies (IBs). To obtain the protein product in an active (native) soluble form, the IBs must be first solubilized, and thereafter, the soluble, often denatured and reduced protein must be refolded. Several technically feasible alternatives to conduct IBs solubilization and on-column refolding have been proposed in recent years. However, rarely these on-column refolding alternatives have been evaluated from an economical point of view, questioning the feasibility of their implementation at a preparative scale. The presented study assesses the economic performance of four distinct process alternatives that include pH induced IBs solubilization and protein refolding (pH_IndSR); IBs solubilization using urea, dithiothreitol (DTT), and alkaline pH followed by batch size-exclusion protein refolding; inclusion bodies (IBs) solubilization using urea, DTT, and alkaline pH followed by simulated moving bed (SMB) size-exclusion protein refolding, and IBs solubilization using urea, DTT and alkaline pH followed by batch dilution protein refolding. The economic performance was judged on the basis of the direct fixed capital, and the production cost per unit of product (P(C)). This work shows that (1) pH_IndSR system is a relatively economical process, because of the low IBs solubilization cost; (2) substituting β-mercaptoethanol for dithiothreithol is an attractive alternative, as it significantly decreases the product cost contribution from the IBs solubilization; and (3) protein refolding by size-exclusion chromatography becomes economically attractive by changing the mode of operation of the chromatographic reactor from batch to continuous using SMB technology.     

Feasibility of acrylic acid production by fermentation

Acrylic acid might become an important target for fermentative production from sugars on bulk industrial scale, as an alternative to its current production from petrochemicals. Metabolic engineering approaches will be required to develop a host microorganism that may enable such a fermentation process. Hypothetical metabolic pathways for insertion into a host organism are discussed. The pathway should have plausible mass and redox balances, plausible biochemistry, and plausible energetics, while giving the theoretically maximum yield of acrylate on glucose without the use of aeration or added electron acceptors. Candidate metabolic pathways that might lead to the theoretically maximum yield proceed via -alanine, methylcitrate, or methylmalonate-CoA. The energetics and enzymology of these pathways, including product excretion, should be studied in more detail to confirm this. Expression of the selected pathway in a host organism will require extensive genetic engineering. A 100,000-tons/year fermentation process for acrylic acid production, including product recovery, was conceptually designed based on the supposition that an efficient host organism for acrylic acid production can indeed be developed. The designed process is economically competitive when compared to the current petrochemical process for acrylic acid. Although the designed process is highly speculative, it provides a clear incentive for development of the required microbial host, especially considering the environmental sustainability of the designed process.     

Relation between cell disruption conditions, cell debris particle size, and inclusion body release

The efficiency of physical separation of inclusion bodies from cell debris is related to cell debris size and inclusion body release and both factors should be taken into account when designing a process. In this work, cell disruption by enzymatic treatment with lysozyme and cellulase, by homogenization, and by homogenization with ammonia pretreatment is discussed. These disruption methods are compared on the basis of inclusion body release, operating costs, and cell debris particle size. The latter was measured with cumulative sedimentation analysis in combination with membrane-associated protein quantification by SDS-PAGE and a spectrophotometric peptidoglycan quantification method. Comparison of the results obtained with these two cell debris quantification methods shows that enzymatic treatment yields cell debris particles with varying chemical composition, while this is not the case with the other disruption methods that were investigated. Furthermore, the experiments show that ammonia pretreatment with homogenization increases inclusion body release compared to homogenization without pretreatment and that this pretreatment may be used to control the cell debris size to some extent. The enzymatic disruption process gives a higher product release than homogenization with or without ammonia pretreatment at lower operating costs, but it also yields a much smaller cell debris size than the other disruption process. This is unfavorable for centrifugal inclusion body purification in this case, where cell debris is the component going to the sediment and the inclusion body is the floating component. Nevertheless, calculations show that centrifugal separation of inclusion bodies from the enzymatically treated cells gives a high inclusion body yield and purity.