846 research outputs found
Management of Turcicum leaf blight [Exserohilum turcicum (Pass.) Leonard & Suggs] of maize (Zea mays L.) through integration of host resistance and fungicide at Bako, western Ethiopia
Open Access JournalTurcicum leaf blight (TLB) (Exserohilum turcicum) is a major disease affecting maize production in western Ethiopia. The objectives of this study were to determine the effect of maize varieties integrated with fungicides on epidemics of turcicum leaf blight; to determine the effect of turcicum leaf blight severity on yield and yield components of maize; and to assess the cost and benefit of using fungicides. The field experiment was conducted at Bako Agricultural Research Center in 2014 main cropping season using six maize varieties (BH-540, BH-543, BH-546, BH-660, BH-661 and AMHQ-760) integrated with foliar sprays of the systemic fungicide propiconazole (Tilt) at the rate of 350 ml ha-1 and the contact fungicide mancozeb (Dithane M-45) at 2.6 kg ha-1. The experiment was arranged in 3 × 6 factorial combinations in split plot design with three replications. A pinch of ground maize leaf infected by E. turcicum was inoculated at third-fifth leaves. Unsprayed plots were left as control or check for each variety. Disease severity was scored using 1 to 5 scale on 12 randomly-tagged plants in the central rows. Integration effects of varieties with fungicides significantly affected the grain yield and thousand kernel weight (TKW) of maize varieties. The highest (11383 kg ha-1) grain yield was obtained from propiconazole-treated hybrid maize variety BH-546. Turcicum leaf blight resulted in grain yield losses of up to 40.7% on the unsprayed plots of the susceptible variety BH-543. Percent severity index, AUDPC, incidence and disease progress rates were negatively correlated with yield components regardless of grain yield loss. The highest marginal benefit (ETB 48,801.28 ha-1) and marginal rate of return (ETB 6.33) were obtained from propiconazole-treated varieties BH-543 and BH-546, respectively. This study contributes to integrated TLB management options, and to make a valid recommendation for TLB management strategy, the study should be repeated over years and locations where TLB of maize is of major economic importance
Visceral leishmaniasis patients display altered composition and maturity of neutrophils as well as impaired neutrophil effector functions
Immunologically, active visceral leishmaniasis (VL) is characterised by profound immunosuppression, severe systemic inflammatory responses and an impaired capacity to control parasite replication. Neutrophils are highly versatile cells, which play a crucial role in the induction as well as the resolution of inflammation, the control of pathogen replication and the regulation of immune responses. Neutrophil functions have been investigated in human cutaneous leishmaniasis, however, their role in human visceral leishmaniasis is poorly understood. In the present study we evaluated the activation status and effector functions of neutrophils in patients with active VL and after successful anti-leishmanial treatment. Our results show that neutrophils are highly activated and have degranulated; high levels of arginase, myeloperoxidase and elastase, all contained in neutrophils’ granules, were found in the plasma of VL patients. In addition, we show that a large proportion of these cells are immature. We also analysed effector functions of neutrophils that are essential for pathogen clearance and show that neutrophils have an impaired capacity to release neutrophil extracellular traps, produce reactive oxygen species and phagocytose bacterial particles, but not Leishmania parasites. Our results suggest that impaired effector functions, increased activation and immaturity of neutrophils play a key role in the pathogenesis of VL
The impacts of public participation in area-based urban regeneration: a case study of the London Borough of Newham
MPhilPublic participation is a key part of the urban regeneration policies in Britain strongly promoted by the New Labour government. The main aim of this study is to investigate the impacts of public participation in area-based urban regeneration where poverty and multiple deprivation are prevalent. The case study area is the London Borough of Newham, a borough that benefits from many of these policy initiatives for a variety of aspects of social, economic and environmental regeneration. Following the completion of their budgeted project life, however, the outcomes of many of the regeneration initia-tives in Newham and elsewhere are not always sustainable. One of the many possible explanations for the failure of initiatives to secure a long-term improvement in the qual-ity of life of the residents is the lack of ownership by local people which is a conse-quence of non- or little public participation in the regeneration process. This often re-flects the almost non-existence of social networks among communities undergoing re-generation and the lack of empowerment of residents from the outset and throughout the lifetime of projects.
The thesis argues that a good stock of social networks and well developed community empowerment will lead to a higher level of participation that could help regeneration initiatives to become more sustainable. It is based on a programme of research that used a range of mixed methods, including surveys, interviews and observation, to investigate the nature of participation in Newham regeneration settings. The findings explore the extent of participation and consider the views of a range of stakeholders on its role in the regeneration process. As well as critically evaluating current Newham regeneration initiatives in relation to the degree to which they meaningfully encourage public partici-pation, the study also sets out to develop ideal models of participation. It explores dif-ferent approaches to engaging with local people and social networks at neighbourhood level, and emphasises to the importance of evaluating regeneration in relation to its par-ticipatory goals. The thesis concludes by reiterating the importance of a meaningful public participation in the national and local policy regimes. It also sets out the signifi-cance of the research in understanding the role of participation in Britain’s area based urban regeneration strategies
On the variational limits of lattice energies on prestrained elastic bodies
We study the asymptotic behaviour of the discrete elastic energies in
presence of the prestrain metric , assigned on the continuum reference
configuration . When the mesh size of the discrete lattice in
goes to zero, we obtain the variational bounds on the limiting (in the sense of
-limit) energy. In case of the nearest-neighbour and
next-to-nearest-neibghour interactions, we derive a precise asymptotic formula,
and compare it with the non-Euclidean model energy relative to
Linearization and localization of nonconvex functionals motivated by nonlinear peridynamic models
We consider a class of nonconvex energy functionals that lies in the
framework of the peridynamics model of continuum mechanics. The energy
densities are functions of a nonlocal strain that describes deformation based
on pairwise interaction of material points, and as such are nonconvex with
respect to nonlocal deformation. We apply variational analysis to investigate
the consistency of the effective behavior of these nonlocal nonconvex
functionals with established classical and peridynamic models in two different
regimes. In the regime of small displacement, we show the model can be
effectively described by its linearization. To be precise, we rigorously derive
what is commonly called the linearized bond-based peridynamic functional as a
-limit of nonlinear functionals. In the regime of vanishing
nonlocality, the effective behavior the nonlocal nonconvex functionals is
characterized by an integral representation, which is obtained via
-convergence with respect to the strong topology. We also prove
various properties of the density of the localized quasiconvex functional such
as frame-indifference and coercivity. We demonstrate that the density vanishes
on matrices whose singular values are less than or equal to one. These results
confirm that the localization, in the context of -convergence, of
peridynamic-type energy functionals exhibit behavior quite different from
classical hyperelastic energy functionals.Comment: 30 page
Statistička analiza nanokapsuliranja niskomolekularnog heparina
The objective of this study was to use Box-Behnken design (BBD) to investigate the influence of formulation variables on the properties of heparin-loaded poly(lactic-co-glycolic acid) (PLGA)-Eudragit-RLPO (E-RLPO) nanoparticles (NP) in terms of mean diameter (as size) and drug encapsulation efficiency. The NPs were prepared by the double emulsion solvent evaporation method. The independent variables were: X1 olymer mass ratio (PLGA:E-RLPO) in the oil phase, X2 concentration of polyvinyl alcohol (PVA) as emulsion stabilizer, and X3 volume of the external aqueous phase (W2). Particle size (analyzed by dynamic light scattering) and encapsulation efficiency (EE, estimated by spectrophotometry) were the investigated responses. The polynomial equation obtained from regression analysis of the reduced model (p = 0.0002, F = 25.7952 and R2 = 0.96) provided an excellent fit. The optimal size for the NP was found to be 134.2 ± 16.5 nm with formulation variables of 48.2:61.8, 0.321 (%, m/V) and 263 mL for X1, X2 and X3, respectively. Probably, due to electrostatic interaction between the negatively charged drug and the positively charged E-RLPO, the percent EE of heparin was between 74.4 ± 6.5 % (lowest value) and 92.1 ± 5.3 % (highest value). The data suggest that BBD is a useful tool in rational design of heparin-loaded NPs.Box-Behnkenovo dizajniranje (BBD) primijenjeno je za praćenje utjecaja formulacijskih varijabli na svojstva nanočestica (NP) s heparinom. Za izradu nanočestica korišten je kopolimer mliječne i glikolne kiseline (PLGA) i Eudragit-RLPO (E-RLPO). Nanočestice su pripravljene metodom dvostruke evaporacije otapala iz emulzije. Nezavisne varijable bile su: X1 omjer masa polimera (PLGA : E-RLPO) u uljnoj fazi, X2 koncentracija polivinil alkohola (PVA) kao stabilizatora emulzije i X3 volumen vanjske vodene faze (W2). Zavisne varijable bile su veličina čestica (analizirana pomoću dinamičkog rasapa svjetlosti) i učinkovitost inkapsuliranja (EE) (praćena spektrofotometrijski). Polinomska jednadžba dobivena regresijskom analizom reduciranog modela odlično je odgovarala (p = 0,0002, F = 25,7952 i R2 = 0,96). Optimalna veličina nanočestica bila je 134,2 ± 16,5 nm s formulacijskim varijablama 48,2:61,8, 0,321 (%, m/V) i 263 mL for X1, X2 odnosno X3. Vjerojatno je zbog elektrostatskih interakcija između negativno nabijene ljekovite tvari i pozitivno nabijenog E-RLPO učinkovitost inkapsuliranja heparina varirala od 74,4 ± 6,5 % (najniža vrijednost) do 92,1 ± 5,3 % (najviša vrijednost). Rezultati sugeriraju da je BBD vrlo korisno u racionalnom dizajniranju nanočestica s heparinom
Effect of graded levels of Tagasaste (Chamaecytisus palmensis) leaves supplementation on performance of yearling Menz sheep in Ethiopian Highlands
The effects of supplementation with graded levels of tagasaste (Chamaecytisus palmensis) leaves on feed intake, digestibility, and body weight gain (BWG) and carcass characteristics were studied using thirty yearling and intact male Menz sheep. The sheep were blocked into six blocks of five sheep based on their initial body weight and animals from each block were randomly assigned to five treatment groups with six replications per treatment in randomized complete block design (RBCD). Barley straw was fed ad libitum as a sole diet in treatment 1 (T1) and as a basal diet supplemented with 100, 200, 300 and 400g dried tagasaste leaf in the other treatments i.e. T2, T3, T4 and T5, respectively. A 90- day growth experiment and 7- day digestibility trial were conducted. Dry matter (DM), organic matter (OM), and crude protein (CP) intakes increased (P0.05) among treatments, but dressing percentage on empty body weight basis have higher than on slaughter weight basis this imply that the influence of digesta. Supplementing a basal diet of barley straw with tagasaste leaves improved DM intake, BWG, digestibility of nutrients and carcass. It is concluded that 400g/d/head of tagasaste leaf can serve as a protein supplement to low quality feed during dry season for efficient performance of sheep
IL-17 Receptor Signaling in Oral Epithelial Cells Is Critical for Protection against Oropharyngeal Candidiasis
Signaling through the IL-17 receptor (IL-17R) is required to prevent oropharyngeal candidiasis (OPC) in mice and humans. However, the IL-17-responsive cell type(s) that mediate protection are unknown. Using radiation chimeras we were able to rule out a requirement for IL-17RA in the hematopoietic compartment. We saw remarkable concordance of IL-17-controlled gene expression in C. albicans-infected human oral epithelial cells (OECs) and in tongue tissue from mice with OPC. To interrogate the role of the IL-17R in OECs, we generated mice with conditional deletion of IL-17RA in superficial oral and esophageal epithelial cells (Il17ra(ΔK13)). Following oral Candida infection, Il17ra(ΔK13) mice exhibited fungal loads and weight loss indistinguishable from Il17ra(−/−) mice. Susceptibility in Il17ra(ΔK13) mice correlated with expression of the antimicrobial peptide β-defensin 3 (BD3, Defb3). Consistently, Defb3(−/−) mice were susceptible to OPC. Thus, OECs dominantly control IL-17R-dependent responses to OPC through regulation of BD3expression
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