To date, projections of human migration induced by sea-level change (SLC) largely suggest large-scale displacement away from vulnerable coastlines. However, results from our model of Bangladesh ...suggest counterintuitively that people will continue to migrate toward the vulnerable coastline irrespective of the flooding amplified by future SLC under all emissions scenarios until the end of this century. We developed an empirically calibrated agent-based model of household migration decision-making that captures the multi-faceted push, pull and mooring influences on migration at a household scale. We then exposed ∼4800 000 simulated migrants to 871 scenarios of projected 21st-century coastal flooding under future emissions pathways. Our model does not predict flooding impacts great enough to drive populations away from coastlines in any of the scenarios. One reason is that while flooding does accelerate a transition from agricultural to non-agricultural income opportunities, livelihood alternatives are most abundant in coastal cities. At the same time, some coastal populations are unable to migrate, as flood losses accumulate and reduce the set of livelihood alternatives (so-called 'trapped' populations). However, even when we increased access to credit, a commonly-proposed policy lever for incentivizing migration in the face of climate risk, we found that the number of immobile agents actually rose. These findings imply that instead of a straightforward relationship between displacement and migration, projections need to consider the multiple constraints on, and preferences for, mobility. Our model demonstrates that decision-makers seeking to affect migration outcomes around SLC would do well to consider individual-level adaptive behaviors and motivations that evolve through time, as well as the potential for unintended behavioral responses.
Certification schemes that aim to provide an assurance on animal welfare have been developed in many countries but there is no internationally agreed mechanism for recognising the equivalence of ...animal welfare schemes. The lack of standardisation is a complication in international trade as the lack of clarity may impede demand for products from animals reared according to specified levels of welfare. An important first step is to define a credible best practice framework for animal welfare certification schemes that could apply in any country. Schemes may aim to provide assurance on minimum levels of welfare or may also aim to promote welfare improvement within their scheme membership. It is proposed here that certification schemes wishing to make animal welfare claims could adopt a scheme level continuous improvement approach, as already used in quality and environmental certification schemes, to promote improvement at a farm level. It is suggested that this can be achieved by using the following four generic principles. Firstly the scheme can operate a management system that co-ordinates scheme activities which actively promote improvement in animal welfare within participating farms. This management system should include the following generic steps: plan (establish the objectives including desired outcomes, scheme requirements and monitoring processes), do (implement scheme inspection systems and support structures), check (measure and monitor the process and results) and improve (take action to improve performance). Secondly the scheme should develop progressive resources and outcomes requirements that comply with relevant legislation, encourage the provision of opportunities valued by the animals, promote farm level continuous improvement in important welfare outcomes and require innovation not to compromise welfare goals. Thirdly the scheme should target its assessment and support resources on important welfare concerns. Activities should include assessment of relevant welfare requirements and outcomes, promoting interest amongst farmers in their management, ensuring technical advice is available and insisting on remedial action for those farmers with consistent poor outcomes. Finally by taking an evidence-based, participatory and transparent approach the scheme should also embrace external scrutiny and involvement.
•Animal welfare certification schemes are an important part of food chain integrity.•Schemes can use resource, outcome or continuous improvement-based approaches.•There are no international standards for higher welfare schemes.•Schemes should include a scheme level management system that actively promotes farm level continuous improvement.
Climate change is likely to drive migration from environmentally stressed areas. However quantifying short and long-term movements across large areas is challenging due to difficulties in the ...collection of highly spatially and temporally resolved human mobility data. In this study we use two datasets of individual mobility trajectories from six million de-identified mobile phone users in Bangladesh over three months and two years respectively. Using data collected during Cyclone Mahasen, which struck Bangladesh in May 2013, we show first how analyses based on mobile network data can describe important short-term features (hours–weeks) of human mobility during and after extreme weather events, which are extremely hard to quantify using standard survey based research. We then demonstrate how mobile data for the first time allow us to study the relationship between fundamental parameters of migration patterns on a national scale. We concurrently quantify incidence, direction, duration and seasonality of migration episodes in Bangladesh. While we show that changes in the incidence of migration episodes are highly correlated with changes in the duration of migration episodes, the correlation between in- and out-migration between areas is unexpectedly weak. The methodological framework described here provides an important addition to current methods in studies of human migration and climate change.
Large-scale data from digital infrastructure, like mobile phone networks, provides rich information on the behavior of millions of people in areas affected by climate stress. Using anonymized data on ...mobility and calling behavior from 5.1 million Grameenphone users in Barisal Division and Chittagong District, Bangladesh, we investigate the effect of Cyclone Mahasen, which struck Barisal and Chittagong in May 2013. We characterize spatiotemporal patterns and anomalies in calling frequency, mobile recharges, and population movements before, during and after the cyclone. While it was originally anticipated that the analysis might detect mass evacuations and displacement from coastal areas in the weeks following the storm, no evidence was found to suggest any permanent changes in population distributions. We detect anomalous patterns of mobility both around the time of early warning messages and the storm’s landfall, showing where and when mobility occurred as well as its characteristics. We find that anomalous patterns of mobility and calling frequency correlate with rainfall intensity (
r
= .75,
p
< 0.05) and use calling frequency to construct a spatiotemporal distribution of cyclone impact as the storm moves across the affected region. Likewise, from mobile recharge purchases we show the spatiotemporal patterns in people’s preparation for the storm in vulnerable areas. In addition to demonstrating how anomaly detection can be useful for modeling human adaptation to climate extremes, we also identify several promising avenues for future improvement of disaster planning and response activities.
NAD+-reducing NiFe hydrogenases are valuable biocatalysts for H2-based energy conversion and the regeneration of nucleotide cofactors. While most hydrogenases are sensitive toward O2 and elevated ...temperatures, the soluble NAD+-reducing NiFe hydrogenase from Hydrogenophilus thermoluteolus (HtSH) is O2-tolerant and thermostable. Thus, it represents a promising candidate for biotechnological applications. Here, we have investigated the catalytic activity and active-site structure of native HtSH and variants in which a glutamate residue in the active-site cavity was replaced by glutamine, alanine, and aspartate. Our biochemical, spectroscopic, and theoretical studies reveal that at least two active-site states of oxidized HtSH feature an unusual architecture in which the glutamate acts as a terminal ligand of the active-site nickel. This observation demonstrates that crystallographically observed glutamate coordination represents a native feature of the enzyme. One of these states is diamagnetic and characterized by a very high stretching frequency of an iron-bound active-site CO ligand. Supported by density-functional-theory calculations, we identify this state as a high-valent species with a biologically unprecedented formal Ni(IV) ground state. Detailed insights into its structure and dynamics were obtained by ultrafast and two-dimensional infrared spectroscopy, demonstrating that it represents a conformationally strained state with unusual bond properties. Our data further show that this state is selectively and reversibly formed under oxic conditions, especially upon rapid exposure to high O2 levels. We conclude that the kinetically controlled formation of this six-coordinate high-valent state represents a specific and precisely orchestrated stereoelectronic response toward O2 that could protect the enzyme from oxidative damage.
The secondary loss of neurons and glia over the first 24 h after spinal cord injury (SCI) contributes to the permanent functional deficits that are the unfortunate consequence of SCI. The progression ...of this acute secondary cell death in specific neuronal and glial populations has not previously been investigated in a quantitative manner. We used a well-characterized model of SCI to analyze the loss of ventral motoneurons (VMN) and ventral funicular astrocytes and oligodendrocytes at 15 min and 4, 8, and 24 h after an incomplete midthoracic contusion injury in the rat. We found that both the length of lesion and the length of spinal cord devoid of VMN increased in a time-dependent manner. The extent of VMN loss at specified distances rostral and caudal to the injury epicenter progressed symmetrically with time. Neuronal loss was accompanied by a loss of glial cells in ventral white matter that was significant at the epicenter by 4 h after injury. Oligodendrocyte loss followed the same temporal pattern as that of VMN while astrocyte loss was delayed. This information on the temporal–spatial pattern of cell loss can be used to investigate mechanisms involved in secondary injury of neurons and glia after SCI.
The CpFe(CO)(CN)2− unit is an excellent structural model for the Fe(CO)(CN)2 moiety of the active site found in NiFe hydrogenases. Ultrafast infrared (IR) pump–probe and 2D-IR spectroscopy have ...been used to study KCpFe(CO)(CN)2 (M1) in a range of protic and polar solvents and as a dry film. Measurements of anharmonicity, intermode vibrational coupling strength, vibrational relaxation time, and solvation dynamics of the CO and CN stretching modes of M1 in H2O, D2O, methanol, dimethyl sulfoxide, and acetonitrile reveal that H-bonding to the CN ligands plays an important role in defining the spectroscopic characteristics and relaxation dynamics of the Fe(CO)(CN)2 unit. Comparisons of the spectroscopic and dynamic data obtained for M1 in solution and in a dry film with those obtained for the enzyme led to the conclusion that the protein backbone forms an important part of the bimetallic active site environment via secondary coordination sphere interactions.
The foot and mouth disease (FMD) epidemic in the UK in 2001 highlighted the threat of infectious diseases to rare and valuable livestock and stimulated a renewed interest in biosecurity and ...conservation. However, not all diseases resemble FMD: their transmission routes and pathological effects vary greatly, so biosecurity strategies must take this into account. Realism is also needed as to which diseases to exclude and which will have to be tolerated. The aim should be to minimise disease generally and to exclude those diseases that threaten the existence of livestock or preclude their national or international movement. Achieving this requires a team effort, bearing in mind the livestock species involved, the farming system ('open' or 'closed') and the premises. Effective biosecurity demands that practically every aspect of farm life is controlled, including movements of people, vehicles, equipment, food, manure, animal carcasses and wildlife. Above all, biosecurity strategies must cover the disease risks associated with moving the livestock themselves and this will require quarantine if adult or juvenile animals are imported into the herd or flock. The present paper emphasises the important role that reproductive technologies, such as artificial insemination and embryo transfer, can have in biosecurity strategies because they offer much safer ways for getting new genetic materials into herds/flocks than bringing in live animals. Embryo transfer is especially safe when the sanitary protocols promoted by the International Embryo Transfer Society and advocated by the Office International des Epizooties (the 'World Organisation for Animal Health') are used. Embryo transfer can also allow the full genetic complement to be salvaged from infected animals. Cryobanking of genetic materials, especially embryos, is another valuable biosecurity strategy because it enables their storage for conservation in the face of contingencies, such as epidemic disease and other catastrophes.
PDF
![Understanding the [NiFe] Hy...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1520-6106_1520-5207/small "Understanding the [NiFe] Hydrogenase Active Site Environment through Ultrafast Infrared and 2D-IR Spectroscopy of the Subsite Analogue K[CpFe(CO)(CN)2] in Polar and Protic Solvents")
