Towards mitigation of greenhouse gases by small changes in farming practices: understanding local barriers in Spain.

Small changes in agricultural practices have a large potential for reducing greenhouse gas emissions. However, the implementation of such practices at the local level is often limited by a range of barriers. Understanding the barriers is essential for defining effective measures, the actual mitigation potential of the measures, and the policy needs to ensure implementation. Here we evaluate behavioural, cultural, and policy barriers for implementation of mitigation practices at the local level that imply small changes to farmers. The choice of potential mitigation practices relevant to the case study is based on a literature review of previous empirical studies. Two methods that include the stakeholders? involvement (experts and farmers) are undertaken for the prioritization of these potential practices: (a) Multi-criteria analysis (MCA) of the choices of an expert panel and (b) Analysis of barriers to implementation based on a survey of farmers. The MCA considers two future climate scenarios ? current climate and a drier and warmer climate scenario. Results suggest that all potential selected practices are suitable for mitigation considering multiple criteria in both scenarios. Nevertheless, if all the barriers for implementation had the same influence, the preferred mitigation practices in the case study would be changes in fertilization management and use of cover crops. The identification of barriers for the implementation of the practices is based on the econometric analysis of surveys given to farmers. Results show that farmers? environmental concerns, financial incentives and access to technical advice are the main factors that define their barriers to implementation. These results may contribute to develop effective mitigation policy to be included in the 2020 review of the European Union Common Agricultural Policy.

Gender differences of the spanish adult population in barriers to active living

Proyecto I+D+i DEP19801: Gender differences of the spanish adult population in barriers to active living

Gender differences of the spanish adult population in cultural barriers to active living

Proyecto I+D+i DEP19801: Gender differences of the spanish adult population in cultural barriers to active living

Gender differences of the spanish adult population in barriers to active living

Social research on the needs, barriers and innovations in sport and physical activities to adult women in Spain

Vehicle induced loads on pedestrian barriers

This paper is a continuation of a previous one, Sanz-Andrés, Santiago-Prowald, Baker and Quinn (J. Wind Eng. Ind. Aerodyn. 91 (2003) 925) concerning the loads generated on a structural panel (traffic sign) by vehicle running along the road, although obviously, the results are also applicable to the effects of other moving vehicles such as trains. The structural panel was modelized as a large plate whose largest dimension is perpendicular to the vehicle motion direction. In this paper a similar approach is used to develop a mathematical model for the vehicle-induced load on pedestrian barriers, modelized as a large plate whose largest dimension is parallel to the vehicle motion direction. The purpose of the work is to develop a model simple enough to give analytical results, although with the physical phenomena correctly accounted for, such as to be able to explain, at least qualitatively, the main characteristics of the phenomenon, as observed in the experiments performed by Quinn et al. (J. Wind Eng. Ind. Aerodyn. 89 (2001) 831). Actually, in spite of the model simplicity, results of the theoretical model show a reasonable good quantitative agreement with the experimental results. The aim of this and previous publications is to provide to the transport infrastructure community with some simple tools that can help to explain, and in some cases also to compute, the unsteady loading produced by moving vehicles on persons and installations placed close to the roads or tracks.

Barriers to the adoption of photovoltaic systems: The state of the art

Although photovoltaic (PV) systems have become much more competitive, the diffusion of PV systems still remains low in comparison to conventional energy sources. What are the current barriers hindering the diffusion of PV systems? In order to address this, we conducted an extensive and systematic literature review based on the Web of Science database. Our state-of-the-art review shows that, despite the rapid development and maturity of the technology during the past few years, the adoption of PV systems still faces several barriers. The wide adoption of PV systems-either as a substitute for other electricity power generation systems in urban areas or for rural electrification-is a challenging process. Our results show that the barriers are evident for both low- and high-income economies, encompassing four dimensions: sociotechnical, management, economic, and policy. Although the barriers vary across context, the lessons learned from one study can be valuable to others. The involvement of all stakeholders-adopters, local communities, firms, international organizations, financial institutions, and government-is crucial to foster the adoption.

The meningococcal PilT protein is required for induction of intimate attachment to epithelial cells following pilus-mediated adhesion

The ability of Neisseria meningitidis (MC) to interact with cellular barriers is essential to its pathogenesis. With epithelial cells, this process has been modeled in two steps. The initial stage of localized adherence is mediated by bacterial pili. After this phase, MC disperse and lose piliation, thus leading to a diffuse adherence. At this stage, microvilli have disappeared, and MC interact intimately with cells and are, in places, located on pedestals of actin, thus realizing attaching and effacing (AE) lesions. The bacterial attributes responsible for these latter phenotypes remain unidentified. Considering that bacteria are nonpiliated at this stage, pili cannot be directly responsible for this effect. However, the initial phase of pilus-mediated localized adherence is required for the occurrence of diffuse adherence, loss of microvilli, and intimate attachment, because nonpiliated bacteria are not capable of such a cellular interaction. In this work, we engineered a mutation in the cytoplasmic nucleotide-binding protein PilT and showed that this mutation increased piliation and abolished the dispersal phase of bacterial clumps as well as the loss of piliation. Furthermore, no intimate attachment nor AE lesions were observed. On the other hand, PilT− MC remained adherent as piliated clumps at all times. Taken together these data demonstrate that the induction of diffuse adherence, intimate attachment, and AE lesions after pilus-mediated adhesion requires the cytoplasmic PilT protein.

Transgene organization in rice engineered through direct DNA transfer supports a two-phase integration mechanism mediated by the establishment of integration hot spots

Organization of transgenes in rice transformed through direct DNA transfer strongly suggests a two-phase integration mechanism. In the “preintegration” phase, transforming plasmid molecules (either intact or partial) are spliced together. This gives rise to rearranged transgenic sequences, which upon integration do not contain any interspersed plant genomic sequences. Subsequently, integration of transgenic DNA into the host genome is initiated. Our experiments suggest that the original site of integration acts as a hot spot, facilitating subsequent integration of successive transgenic molecules at the same locus. The resulting transgenic locus may have plant DNA separating the transgenic sequences. Our data indicate that transformation through direct DNA transfer, specifically particle bombardment, generally results in a single transgenic locus as a result of this two-phase integration mechanism. Transgenic plants generated through such processes may, therefore, be more amenable to breeding programs as the single transgenic locus will be easier to characterize genetically. Results from direct DNA transfer experiments suggest that in the absence of protein factors involved in exogenous DNA transfer through Agrobacterium, the qualitative and/or quantitative efficiency of transformation events is not compromised. Our results cast doubt on the role of Agrobacterium vir genes in the integration process.

Gene therapy in allergic encephalomyelitis using myelin basic protein-specific T cells engineered to express latent transforming growth factor-β1

A myelin basic protein (MBP)-specific BALB/c T helper 1 (Th1) clone was transduced with cDNA for murine latent transforming growth factor-β1 (TGF-β1) by coculture with fibroblasts producing a genetically engineered retrovirus. When SJL x BALB/c F1 mice, immunized 12–15 days earlier with proteolipid protein in complete Freund’s adjuvant, were injected with 3 × 106 cells from MBP-activated untransduced cloned Th1 cells, the severity of experimental allergic encephalomyelitis (EAE) was slightly increased. In contrast, MBP-activated (but not resting) latent TGF-β1-transduced T cells significantly delayed and ameliorated EAE development. This protective effect was negated by simultaneously injected anti-TGF-β1. The transduced cells secreted 2–4 ng/ml of latent TGF-β1 into their culture medium, whereas control cells secreted barely detectable amounts. mRNA profiles for tumor necrosis factor, lymphotoxin, and interferon-γ were similar before and after transduction; interleukin-4 and -10 were absent. TGF-β1-transduced and antigen-activated BALB/c Th1 clones, specific for hemocyanin or ovalbumin, did not ameliorate EAE. Spinal cords from mice, taken 12 days after receiving TGF-β1-transduced, antigen-activated cells, contained detectable amounts of TGF-β1 cDNA. We conclude that latent TGF-β1-transduced, self-reactive T cell clones may be useful in the therapy of autoimmune diseases.

Maternal death and obstetric care audits in Nigeria : a systematic review of barriers and enabling factors in the provision of emergency care

Acknowledgements We would like to thank Yutaka Osakabe for co-ordinating the retrieval of full text articles. The John D. and Catherine T. MacArthur Foundation supported this study, grant number 12-100074-000-INP

Barriers to recombination between closely related bacteria: MutS and RecBCD inhibit recombination between Salmonella typhimurium and Salmonella typhi

Previous studies have shown that inactivation of the MutS or MutL mismatch repair enzymes increases the efficiency of homeologous recombination between Escherichia coli and Salmonella typhimurium and between S. typhimurium and Salmonella typhi. However, even in mutants defective for mismatch repair the recombination frequencies are 102- to 103-fold less than observed during homologous recombination between a donor and recipient of the same species. In addition, the length of DNA exchanged during transduction between S. typhimurium and S. typhi is less than in transductions between strains of S. typhimurium. In homeologous transductions, mutations in the recD gene increased the frequency of transduction and the length of DNA exchanged. Furthermore, in mutS recD double mutants the frequency of homeologous recombination was nearly as high as that seen during homologous recombination. The phenotypes of the mutants indicate that the gene products of mutS and recD act independently. Because S. typhimurium and S. typhi are ≈98–99% identical at the DNA sequence level, the inhibition of recombination is probably not due to a failure of RecA to initiate strand exchange. Instead, these results suggest that mismatches act at a subsequent step, possibly by slowing the rate of branch migration. Slowing the rate of branch migration may stimulate helicase proteins to unwind rather than extend the heteroduplex and leave uncomplexed donor DNA susceptible to further degradation by RecBCD exonuclease.

Characterization of a genetically engineered inactivation-resistant coagulation factor VIIIa

Individuals with hemophilia A require frequent infusion of preparations of coagulation factor VIII. The activity of factor VIII (FVIII) as a cofactor for factor IXa in the coagulation cascade is limited by its instability after activation by thrombin. Activation of FVIII occurs through proteolytic cleavage and generates an unstable FVIII heterotrimer that is subject to rapid dissociation of its subunits. In addition, further proteolytic cleavage by thrombin, factor Xa, factor IXa, and activated protein C can lead to inactivation. We have engineered and characterized a FVIII protein, IR8, that has enhanced in vitro stability of FVIII activity due to resistance to subunit dissociation and proteolytic inactivation. FVIII was genetically engineered by deletion of residues 794-1689 so that the A2 domain is covalently attached to the light chain. Missense mutations at thrombin and activated protein C inactivation cleavage sites provided resistance to proteolysis, resulting in a single-chain protein that has maximal activity after a single cleavage after arginine-372. The specific activity of partially purified protein produced in transfected COS-1 monkey cells was 5-fold higher than wild-type (WT) FVIII. Whereas WT FVIII was inactivated by thrombin after 10 min in vitro, IR8 still retained 38% of peak activity after 4 hr. Whereas binding of IR8 to von Willebrand factor (vWF) was reduced 10-fold compared with WT FVIII, in the presence of an anti-light chain antibody, ESH8, binding of IR8 to vWF increased 5-fold. These results demonstrate that residues 1690–2332 of FVIII are sufficient to support high-affinity vWF binding. Whereas ESH8 inhibited WT factor VIII activity, IR8 retained its activity in the presence of ESH8. We propose that resistance to A2 subunit dissociation abrogates inhibition by the ESH8 antibody. The stable FVIIIa described here provides the opportunity to study the activated form of this critical coagulation factor and demonstrates that proteins can be improved by rationale design through genetic engineering technology.

Vaccination with irradiated autologous melanoma cells engineered to secrete human granulocyte–macrophage colony-stimulating factor generates potent antitumor immunity in patients with metastatic melanoma

We conducted a Phase I clinical trial investigating the biologic activity of vaccination with irradiated autologous melanoma cells engineered to secrete human granulocyte–macrophage colony-stimulating factor in patients with metastatic melanoma. Immunization sites were intensely infiltrated with T lymphocytes, dendritic cells, macrophages, and eosinophils in all 21 evaluable patients. Although metastatic lesions resected before vaccination were minimally infiltrated with cells of the immune system in all patients, metastatic lesions resected after vaccination were densely infiltrated with T lymphocytes and plasma cells and showed extensive tumor destruction (at least 80%), fibrosis, and edema in 11 of 16 patients examined. Antimelanoma cytotoxic T cell and antibody responses were associated with tumor destruction. These results demonstrate that vaccination with irradiated autologous melanoma cells engineered to secrete granulocyte–macrophage colony-stimulating factor stimulates potent antitumor immunity in humans with metastatic melanoma.

Separation of the arterial wall from blood contact using hydrogel barriers reduces intimal thickening after balloon injury in the rat: The roles of medial and luminal factors in arterial healing

The objective of this study was to clarify the relative roles of medial versus luminal factors in the induction of thickening of the arterial intima after balloon angioplasty injury. Platelet-derived growth factor (PDGF) and thrombin, both associated with thrombosis, and basic fibroblast growth factor (bFGF), stored in the arterial wall, have been implicated in this process. To unequivocally isolate the media from luminally derived factors, we used a 20-μm thick hydrogel barrier that adhered firmly to the arterial wall to block thrombus deposition after balloon-induced injury of the carotid artery of the rat. Thrombosis, bFGF mobilization, medial repopulation, and intimal thickening were measured. Blockade of postinjury arterial contact with blood prevented thrombosis and dramatically inhibited both intimal thickening and endogenous bFGF mobilization. By blocking blood contact on the two time scales of thrombosis and of intimal thickening, and by using local protein release to probe, by reconstitution, the individual roles of PDGF-BB and thrombin, we were able to conclude that a luminally derived factor other than PDGF or thrombin is required for the initiation of cellular events leading to intimal thickening after balloon injury in the rat. We further conclude that a luminally derived factor is required for mobilization of medial bFGF.

RNA-controlled polymorphism in the in vivo assembly of 180-subunit and 120-subunit virions from a single capsid protein

Repeated, specific interactions between capsid protein (CP) subunits direct virus capsid assembly and exemplify regulated protein–protein interactions. The results presented here reveal a striking in vivo switch in CP assembly. Using cryoelectron microscopy, three-dimensional image reconstruction, and molecular modeling, we show that brome mosaic virus (BMV) CP can assemble in vivo two remarkably distinct capsids that selectively package BMV-derived RNAs in the absence of BMV RNA replication: a 180-subunit capsid indistinguishable from virions produced in natural infections and a previously unobserved BMV capsid type with 120 subunits arranged as 60 CP dimers. Each such dimer contains two CPs in distinct, nonequivalent environments, in contrast to the quasi-equivalent CP environments throughout the 180-subunit capsid. This 120-subunit capsid utilizes most of the CP interactions of the 180-subunit capsid plus nonequivalent CP–CP interactions. Thus, the CP of BMV, and perhaps other viruses, can encode CP–CP interactions that are not apparent from mature virions and may function in assembly or disassembly. Shared structural features suggest that the 120- and 180-subunit capsids share assembly steps and that a common pentamer of CP dimers may be an important assembly intermediate. The ability of a single CP to switch between distinct capsids by means of alternate interactions also implies reduced evolutionary barriers between different capsid structures. The in vivo switch between alternate BMV capsids is controlled by the RNA packaged: a natural BMV genomic RNA was packaged in 180-subunit capsids, whereas an engineered mRNA containing only the BMV CP gene was packaged in 120-subunit capsids. RNA features can thus direct the assembly of a ribonucleoprotein complex between alternate structural pathways.