Riparian Ecosystems in the 21st Century: Hotspots for Climate Change Adaptation?

Riparian ecosystems in the 21st century are likely to play a critical role in determining the vulnerability of natural and human systems to climate change, and in influencing the capacity of these systems to adapt. Some authors have suggested that riparian ecosystems are particularly vulnerable to climate change impacts due to their high levels of exposure and sensitivity to climatic stimuli, and their history of degradation. Others have highlighted the probable resilience of riparian ecosystems to climate change as a result of their evolution under high levels of climatic and environmental variability. We synthesize current knowledge of the vulnerability of riparian ecosystems to climate change by assessing the potential exposure, sensitivity, and adaptive capacity of their key components and processes, as well as ecosystem functions, goods and services, to projected global climatic changes. We review key pathways for ecological and human adaptation for the maintenance, restoration and enhancement of riparian ecosystem functions, goods and services and present emerging principles for planned adaptation. Our synthesis suggests that, in the absence of adaptation, riparian ecosystems are likely to be highly vulnerable to climate change impacts. However, given the critical role of riparian ecosystem functions in landscapes, as well as the strong links between riparian ecosystems and human well-being, considerable means, motives and opportunities for strategically planned adaptation to climate change also exist. The need for planned adaptation of and for riparian ecosystems is likely to be strengthened as the importance of many riparian ecosystem functions, goods and services will grow under a changing climate. Consequently, riparian ecosystems are likely to become adaptation ‘hotspots’ as the century unfolds.     

Can Boreal and Temperate Forest Management be Adapted to the Uncertainties of 21st Century Climate Change?

Considerable uncertainties remain about magnitude and character, if not general direction of anthropogenic climate change. Global mean temperature could increase by 1.5–4.5°C or more over historic levels, and extreme weather events—drought, storms, and flooding—are likely to increase greatly in frequency. Although ecologists and foresters agree that the practice of forestry will be transformed under climate change, these uncertainties compound the challenge of achieving sustainable, adaptive forest management. In this aritcle, we (i) present a multidisciplinary synthesis of current knowledge of responses of temperate and boreal tree species and forest communities to climate change, and (ii) outline silvicultural strategies for adapting temperate and boreal forests to confront climate change. Our knowledge synthesis proceeds through critical appraisals of efforts to model future tree distributions and responses to climate change, and reviews physiological, phenological, acclimation, and epigenetic responses to climate. As is the case of climate change itself, there are numerous uncertainties about tree species and provenance responses to climate change. For example, acclimation of respiration and epigenetic conditioning of seed embryos has the potential to buffer species against limited warming. Provenances within species also display idiosyncratic responses to altered climates, implying that soemm varieties will be more resilient or resistant to climate change than others. Genetically determined limits to climatic tolerance, and the limits of tree community resistance and resilience (speed of recovery from disturbance) in the face of climate-related disturbances are largely unknown. These unknowns require managers to adopt a portfolio of silvicultural strategies, which may range from minor modifications of current practices to design of novel multi-species stands that may have no historical analogue. Forest managers must be prepared to respond nimbly as they develop, incorporate new insights about climate change and species responses to warming into their practices. Marshalling all strategies and sources of knowledge should enable forest managers to mount (at least) a partially successful response to the challenges of climate change.     

β-Lactamases and β-Lactamase Inhibitors in the 21st Century

The β-lactams retain a central place in the antibacterial armamentarium. In Gram-negative bacteria, β-lactamase enzymes that hydrolyze the amide bond of the four-membered β-lactam ring are the primary resistance mechanism, with multiple enzymes disseminating on mobile genetic elements across opportunistic pathogens such as Enterobacteriaceae (e.g., Escherichia coli) and non-fermenting organisms (e.g., Pseudomonas aeruginosa). β-Lactamases divide into four classes; the active-site serine β-lactamases (classes A, C and D) and the zinc-dependent or metallo-β-lactamases (MBLs; class B). Here we review recent advances in mechanistic understanding of each class, focusing upon how growing numbers of crystal structures, in particular for β-lactam complexes, and methods such as neutron diffraction and molecular simulations, have improved understanding of the biochemistry of β-lactam breakdown. A second focus is β-lactamase interactions with carbapenems, as carbapenem-resistant bacteria are of grave clinical concern and carbapenem-hydrolyzing enzymes such as KPC (class A) NDM (class B) and OXA-48 (class D) are proliferating worldwide. An overview is provided of the changing landscape of β-lactamase inhibitors, exemplified by the introduction to the clinic of combinations of β-lactams with diazabicyclooctanone and cyclic boronate serine β-lactamase inhibitors, and of progress and strategies toward clinically useful MBL inhibitors. Despite the long history of β-lactamase research, we contend that issues including continuing unresolved questions around mechanism; opportunities afforded by new technologies such as serial femtosecond crystallography; the need for new inhibitors, particularly for MBLs; the likely impact of new β-lactam:inhibitor combinations and the continuing clinical importance of β-lactams mean that this remains a rewarding research area.     

ISCR Elements: Novel Gene-Capturing Systems of the 21st Century?

“Common regions” (CRs), such as Orf513, are being increasingly linked to mega-antibiotic-resistant regions. While their overall nucleotide sequences show little identity to other mobile elements, amino acid alignments indicate that they possess the key motifs of IS91-like elements, which have been linked to the mobility ent plasmids in pathogenic Escherichia coli. Further inspection reveals that they possess an IS91-like origin of replication and termination sites (terIS), and therefore CRs probably transpose via a rolling-circle replication mechanism. Accordingly, in this review we have renamed CRs as ISCRs to give a more accurate reflection of their functional properties. The genetic context surrounding ISCRs indicates that they can procure 5′ sequences via misreading of the cognate terIS, i.e., “unchecked transposition.” Clinically, the most worrying aspect of ISCRs is that they are increasingly being linked with more potent examples of resistance, i.e., metallo-β-lactamases in Pseudomonas aeruginosa and co-trimoxazole resistance in Stenotrophomonas maltophilia. Furthermore, if ISCR elements do move via “unchecked RC transposition,” as has been speculated for ISCR1, then this mechanism provides antibiotic resistance genes with a highly mobile genetic vehicle that could greatly exceed the effects of previously reported mobile genetic mechanisms. It has been hypothesized that bacteria will surprise us by extending their “genetic construction kit” to procure and evince additional DNA and, therefore, antibiotic resistance genes. It appears that ISCR elements have now firmly established themselves within that regimen.     

What Is the Accurate Prevalence of Obesity in Sweden in the 21st Century? Methodological Experiences From the Skaraborg Project

Objective: To examine the impact of non‐response to self‐reported body weight and height in health questionnaires for the estimation of obesity prevalence. Methods and Procedures: A cross‐sectional population‐based health survey in the community of Vara with 16,009 residents (in year 2002) in South‐western Sweden. Participants randomly selected in strata by sex and age among residents being 30–74 years old were consecutively invited to the local health care center for a health examination, including two visits. Self‐reported information on body weight and height were obtained by health questionnaires at the first visit, and measured information on both variables at the second visit. For this study 1,809 subjects (904 men and 905 women) completed both visits (participation rate 81%), and a nurse measured body weight and height of all at visit two. Participants not self‐reporting body weight and/or height at the first visit were defined as non‐responders. Results: Both male and female non‐responders were significantly older than responders. Female non‐responders had significantly higher BMI (29.8 ± 5.8 kg/m²) than female responders (26.6 ± 5.3 kg/m²), (P < 0.001). No similar findings were seen in men. Non‐responders were more likely to be obese than responders both in men (odds ratio (OR) 2.06, 95% confidence interval (CI) 1.03–4.11) and in women (OR 2.24, 95% CI 1.25–4.02). Discussion: Non‐responders to self‐reported body weight and height in health questionnaires contribute to the underestimation of obesity. Measured body weight and height are to prefer when describing the accurate prevalence of obesity in populations.     

Regulating genomics in the 21st century: from logos to pathos?

There is currently an important change in the governance of genomics. In the past, much of the regulatory discussion about genomics has focused on issues of risk. Today, a new discussion is evolving that emphasizes the uncertainties involved in the development and diffusion of genomics into society. The increasing importance of emotional language and the focus on trust in the discussion about genomics reflects the attempt to substitute for the shortcomings of logos with ethos and pathos.     

Cadmium and health in the 21st Century – historical remarks and trends for the future

The first health effect of cadmium (Cd) was lung damage, reported in workers already in the 1930's, while bone effects and proteinuria were reported in the 1940's. After World War II, a bone disease with fractures and severe pain, the itai-itai disease, a form of Cd-induced renal osteomalacia, was identified in Japan. Subsequently, the toxicokinetics and toxicodynamics of Cd were described including its binding to the protein metallothionein. International warnings of health risks from cadmium pollution were issued in the 1970's. WHO, 1992, identified renal dysfunction as the critical effect and a crude quantitative evaluation was presented. In the 1990's population groups in China exposed to Cd via rice were studied and new information on skeletal, renal and reproductive toxicity of Cd was obtained in the ChinaCad project. There was a decrease in Bone Mineral Density (BMD), an increased prevalence of fractures and an increased urinary content of marker proteins of renal dysfunction among persons with long term exposure to Cd. The development of such biomarkers can be seen as a result of applied 'proteomics' research. Variation in metallothionein gene expression was related to development of renal dysfunction, supporting the usefulness of this 'genomic' approach. The ongoing rapid development of 'genomics' and 'proteomics' technologies will improve possibilities for molecular epidemiology studies in the future, providing an even better basis for preventive action. In many countries, Cd exposures are now under better control than in the past. The target for the 21st century is to achieve a totally acceptable exposure situation without adverse health effects from Cd.     

Will Tropical Biodiversity Survive our Approach to Global Change?

Because global change is almost synonymous with climate change, research has emphasized perhaps too much the effects of climate change over other global concerns that might be equally detrimental to biodiversity and humanity. These include unsustainable land use and massive conversion and degradation of natural habitats. Perhaps by the time we understand the effects of global climate change on tropical forests, there may not be any left to admire.     

Are we prepared for animal cell technology in the 21st century?

Large scale animal cell culture for the production of complex therapeutic proteins has been a major success of the biotechnology industry. Today, approximately half of the $ 5 billion annual turnover of the biotechnology industry is based upon this technology, in many cases with reactors of more than 10 m³. As we look towards the 21 st century, however, we can see novel approaches to the production of therapeutic proteins, by means of gene and cellular therapies. These technologies present new engineering challenges to the animal cell technologist. Are we prepared to meet these challenges? The needs include: small-scale reactors for the preparation of autologous cell lines, methods for the production of viruses to be used as vectors in gene therapy, artificial organ and the processing of xenogenic cell lines and tissues for cellular implants in humans. More attention should be given to three-dimensional cell cultures. Mass transfer considerations need to be extended beyond just oxygen transfer, to include cellular communication in small systems; this is becoming increasingly important for the control and optimise growth and product formation. Apart from improvements of large-scale systems, substantial advantages could be gained by studying new methods for the production and delivery of therapeutic proteins, using small-scale cell culture systems. We should adapt teaching, regulatory, patent and clinical infrastructure to meet this challenge in a harmonious way.     

African trypanosomes in the 21st century: what is their future in science and in health?

The African trypanosomes remain well recognised for their role as an interesting model eukaryote for basic science, but are loosing ground in their ability to contribute to understanding common cellular mechanisms. At the same time, the diseases they cause remain as prevalent as ever, but appear increasingly irrelevant in their wider medical, social, economic and political context. What can be done to keep trypanosome biology relevant and vigorous in the 21st century?     

Will Temperature Effects or Phenotypic Plasticity Determine the Thermal Response of a Heterothermic Tropical Bat to Climate Change?

The proportion of organisms exposed to warm conditions is predicted to increase during global warming. To better understand how bats might respond to climate change, we aimed to obtain the first data on how use of torpor, a crucial survival strategy of small bats, is affected by temperature in the tropics. Over two mild winters, tropical free-ranging bats (Nyctophilus bifax, 10 g, n = 13) used torpor on 95% of study days and were torpid for 33.5±18.8% of 113 days measured. Torpor duration was temperature-dependent and an increase in ambient temperature by the predicted 2°C for the 21^st century would decrease the time in torpor to 21.8%. However, comparisons among Nyctophilus populations show that regional phenotypic plasticity attenuates temperature effects on torpor patterns. Our data suggest that heterothermy is important for energy budgeting of bats even under warm conditions and that flexible torpor use will enhance bats’ chance of survival during climate change.     

Is Cassava the Answer to African Climate Change Adaptation?

This paper examines the impacts of climate change on cassava production in Africa, and questions whether cassava can play an important role in climate change adaptation. First, we examine the impacts that climate change will likely have on cassava itself, and on other important staple food crops for Africa including maize, millets, sorghum, banana, and beans based on projections to 2030. Results indicate that cassava is actually positively impacted in many areas of Africa, with ?3.7% to +17.5% changes in climate suitability across the continent. Conversely, for other major food staples, we found that they are all projected to experience negative impacts, with the greatest impacts for beans (?16%?±?8.8), potato (?14.7?±?8.2), banana (?2.5%?±?4.9), and sorghum (?2.66%?±?6.45). We then examined the likely challenges that cassava will face from pests and diseases through the use of ecological niche modeling for cassava mosaic disease, whitefly, brown streak disease and cassava mealybug. The findings show that the geographic distribution of these pests and diseases are projected to change, with both new areas opening up and areas where the pests and diseases are likely to leave or reduce in pressure. We finish the paper by looking at the abiotic traits of priority for crop adaptation for a 2030 world, showing that greater drought tolerance could bring some benefits in all areas of Africa, and that cold tolerance in Southern Africa will continue to be a constraint for cassava despite a warmer 2030 world, hence breeding needs to keep a focus on this trait. Importantly, heat tolerance was not found to be a major priority for crop improvement in cassava in the whole of Africa, but only in localized pockets of West Africa and the Sahel. The paper concludes that cassava is potentially highly resilient to future climatic changes and could provide Africa with options for adaptation whilst other major food staples face challenges.