Eleven orchards of the Vf resistant apple variety Santana that where planted between 1998 and 2000 where monitored for apple scab lesions on fruits form 2002 to 2005. The results where evaluated in respect tot the applied resistance management practices. We conclude that fungicide treatments on the major primary scab infections are the key factor in the resistance management on Vf resistant apple varieties. From a practical viewpoint these early season fungicide applications are also necessary for the control of powdery mildew, as the main Vf- resistant apple cultivars appear to be relatively susceptible to powdery mildew.
relevance will require case-by-case studies. How can we quantify the delay in the build-up of resistance? Measurements of selection, the selection coefficient, or a related quantity, from field experiments or model studies gives some insight, but it does not tell us how much more durable the effective disease control from an at-risk fungicide will be due to using it in a mixture. To be relevant, mixtures must increase effective disease control by at least one growing season. We therefore need to measure the success of a resistance management method in terms of years of effective disease control after the fungicide is introduced (25– 27,60,61). The models calculating the number of years of effective disease control (25–27,60) were parameterized for Mycosphaerella graminicola on winter wheat, and the fungicides pyraclostrobin as the at-risk fungicide and chlorothalonil as the mixing partner. Here we have done additional calculations with two different dose response curves for the mixing component (Fig. 2), one for chlorothalonil and one representing a hypo- thetical mixing partner with a lower disease control efficacy. The findings are summarized in Tables 1 and 2.
11 Read more
The insecticide resistance profile for many areas of the country was determined, each at a specific time, during 2011–2014. However, 9 sites in districts where IRS was being implemented were selected for longitudinal moni- toring of mosquito populations. In these sites, light traps (developed by the US Centers for Disease Control and Pre- vention [CDC]) and pyrethrum spray catches were used to monitor mosquito density and behavior; insecticide bioassays (18) were performed every 6 months to monitor prevalence of resistance. In 2014, the IRMTWG decided that the NMCC should increase the number of sites be- ing monitored from 9 to 24 sentinel sites spread across the country. When resistance is detected by using a diagnostic dose, quantifying the strength of that resistance and de- termining how the resistance may impact vector control are needed. In Burkina Faso, the strength of resistance increased significantly over just 3 years (19), leading to decreased effectiveness of bed nets. Consequently, CDC bottle bioassays (20) will be used to measure intensity of resistance in the original 9 sentinel sites.
Through a large detailed experiment involving crosses between sensitive (QRD14) and strongly resistant (QRD569) strains, we determined that genes for resistance have no particular dominance in most of the various R. dominica life stages, with one notable exception. We also determined that the resistance factors are expressed in all life stages (egg, larva, adult), and eggs and pupae have been confirmed to be the most tolerant life stages, even in resistant insects. This suggests a constitutively expressed resistance factor that does not appear to be 'switched off' at any stage of development.
18 Read more
to organophosphate is good for vector control and resist- ance management. Although, the level of resistance to car- bamate observed in this study may not have any serious implication on vector control, there is a need for constant monitoring and resistance surveillance to prevent resist- ance to these insecticides rising to a level that could affect insecticide resistance management strategies in the coun- try. Environmental variables such as ecology, seasons and land use settings were marginally or non-significantly as- sociated with carbamate and organophosphate resistance (Table 3). Culex species in Ghana and most West African countries are not epidemiologically important but many households spent a considerable amount of money and re- sources to prevent their nuisance [17,18]. Furthermore, the influence of Culex species on the use of insecticide treated net has been highlighted by several studies [19,20]. These reasons emphasise the importance of controlling and monitoring insecticide resistance in Culex species.
10 Read more
Low levels of bendiocarb resistance were detected in An. funestus in the original 1999 baseline . Resistance was still detectable by bioassay and associated with high fre- quencies of an altered AChE resistance mechanism in the 2002–06 collections, which is the likely cause of this resistance. This, coupled with the appearance of car- bamate resistance in Mozambican An. arabiensis, the sec- ond malaria vector in the region (Coleman et al in press), and the high economic costs associated with bendiocarb use, prompted an operational change of insecticide in 2006 back to DDT. The levels of pyrethroid resistance still segregating in An. funestus at this point were considered too high to justify a switch back to pyrethroid treatment. The decline in pyrethroid resistance at some sites suggests that with the correct resistance management strategy in place, pyrethroids may again play a role in southern Mozambique's malaria control programmes . Conclusion
To ensure that we can maintain control in the medium to long term and establish evidence-based insecticide resistance management plans, more than a single new insecticide class will be required, as we already have resistance issues with all existing public health insecticide classes. Ideally, any new insecticide should not be introduced as a single treatment, resulting in a high resistance selection pressure. Introducing several insecticides in rotation, mosaic or mixture formats should reduce the likelihood of resistance selection signifi- cantly, as long as none of the insecticides share a common target site or metabolic detoxification pathway. The current portfolio of IVCC projects is designed to produce three new insecticide classes by around 2023, with no cross-resistance to current insecticide classes. A range of projects have been devel- oped with industrial partners that has resulted in more than 4.5 million compounds being screened in simple mosquito mor- tality tests, with the most promising leads taken forward into further development. An overview of the current portfolio and projected timelines is given in figure 2.
Specific IRM strategies targeting the Aedes genus may be more likely to succeed if they tar- get immature stages rather than imago. Firstly, larvae have no possibility to escape the treat- ment, reducing the possibility for behavioral resistance contrary to adults. Secondly, several larvicides covering 4 chemical classes (organophosphates, juvenile hormone mimics, chitin synthesis inhibitors, and spinosyns), plus a biological agent, Bti, are available for larval control, all of which could be rotated easily, in contrast to space sprays that rely solely on 2 chemical classes (pyrethroids and organophosphates). Bti, due to its unique mode of action as a mixture of toxins, has a high potential for Aedes control and resistance management. After more than 30 years of use, no resistance has been reported so far . The product is cheap, safe, registered in many countries, and can then be widely deployed in regions where mosquitoes have become resistant to chemical insecticides. In areas where IRS and targeted IRS can be massively deployed for dengue control, pyrethroids should not be used as a single treatment but as part of a coordinated rotation using nonpyrethroid insecticides . The use of noninsecticidal tools is an efficient way to reduce the selection pressure on vector populations , and it has the advantage to be applied within an IVM strategy, which aims to improve vector control effi- cacy while optimizing the use of available resources .
22 Read more
Figure 6. The Simulated evolution of glyphosate resistance in A. palmeri populations in continuous glyphosate-resistant cotton when burndown (solid line, black diamonds), first post-emergence (solid line, white circles), second post-emergence (dashed line, black triangles), third post-emergence (dashed line, black crosses) and final post-emergence (dotted line, white triangles) herbicides are substituted for notional alternative herbicide modes of action with identical efficacy. A population is deemed to be resistant when 20% of individuals are phenotypically resistant (RS or RR genotype). Resistance risk is a measure of the proportion of populations (of 1000 runs) in which resistance is predicted at simulation year x.
36 Read more
Some aspects of underlying models within WSW are based on similar models in RIM, although WSW adds much greater temporal resolution and biological detail and realism, as it works on a daily time step. WSW represents a single paddock or section of paddock within a farm and aims to be able to represent any kind of farming system, with crops sown and harvested on any day of the year, although the current version is best suited to simulating a southern Australian agricultural system. Unlike RIM, the model requires detailed daily weather data for the period simulated, and is thus able to simulate the effects of specific variations in such data, such as season-to-season variation in timing of opening rains and differences in weather in different locations. There is also some representation of the effects of different soil types. WSW has been constructed so that new weed species can easily be added to the model and populations including multiple weed species can be simulated without difficulty. The accuracy of these simulations depends of course on the adequacy of the parameterisation of each species included in the model. The level of biological detail in WSW is relatively complex and realistic compared to RIM. For example, multiple seedbank cohorts are represented for different soil layers and age cohorts. Different weed plant cohorts for every separate germination date are also included. Resistance is not explicitly represented in the model at all, although it can be included by assuming a decline in efficacy of a certain herbicide over time.
Global Influenza Surveillance and Response System (GISRS) through its collaborating centers and reference laboratories in 113 member states conducts influenza virus surveillance and provides recommendations regarding the laboratory diagnosis, vaccines, antiviral susceptibility, and risk assess- ment. In addition, GISRS also provides global alerts on the emergence of novel influenza viruses. Therefore, GISRS serves as a single and timely source on worldwide status and management of the influenza virus, including drug-resistant IAV. In addition, CDC (USA) also puts out timely updates and advisories on influenza virus.
14 Read more
To evaluate the impact of pig farm management on the genetic diversity and on the virulence of Campylobacter coli, we characterized isolates from 19 organic pig farms (62 isolates) and from 24 conventional pig farms (58 isolates). The 120 C. coli isolates were typed using pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) and the presence of nine virulence genes was screened using real-time PCR. The capacity of adhesion and invasion of 61 isolates (32 from organic and 29 from conventional farms) were then tested on human intestinal Caco-2 cells. A total of 59 PFGE types and of 50 sequence types (STs) were identified. Twelve PFGE types and nine STs, accounting for 34 and 41.6% of the isolates, respectively, were common between the two production systems with ST854 dominating (18.3% of the isolates). Twenty-nine PFGE types and 25 STs were only found in isolates from organic farms, and 18 PFGE types and 16 STs from conventional farms. No significant differences were found in diversity despite the differences in rearing systems, except at the locus level for the glnA, gltA, and uncA genes. All isolates, regardless of their origin, carried the ceuE, iam, ciaB, and flaA genes and more than 95% of the isolates carried the cadF and cdtABC genes. No significant differences were found in pathogenicity between the two farming systems. The pathogenicity of the C. coli isolates was low compared to C. jejuni control strains tested. The plasmid gene virb11 was detected in only 13 isolates from organic farms; these isolates showed greater invasion capacity than those without this gene. Our study indicates that pig farm management does not significantly affect the diversity and the virulence of Campylobacter coli isolated from pigs. The common genotypes between conventional and organic farms may indicate that some genotypes are adapted to pigs.
10 Read more
In all cases of resistance in aquatics thus far, the underlying issue has been continuous use and /or long-term exposure to the herbicide. This has been the case for most resistance developments in terrestrial cropping systems and it is not surprising that this is same in the aquatic environment. The major difference is the development of resistance without genetic recombination, especially with dioecious hydrilla. This biotype only reproduces asexually in the U.S. so the development of resistance was thought to be minimal, given the clonal and theoretically identical plants. However, it was discovered that genetic variability exists in asexually propagated hydrilla and more than likely other predominantly vegetative species.
11 Read more
DOI: 10.4236/gep.2017.59005 73 Journal of Geoscience and Environment Protection Thus, overlapping frames about the process were co-constructed by the project managers and the local communities, which enabled them to collaborate and implement the process for a relatively important period of time in the different cases. Resistance emerged later due to the change in discourses of the projects or the managers, which triggered the construction of opposing frames. Resistance to change is thus the product of the parties’ interactive discursive choices . The outcome of a change process is thus determined by the interdependence between the people involved and the way in which the process is built. It cannot be understood or explained by the behaviour of an involved individual or an in- teraction but by chains of interactions that happened during the course of the process in which discourses play a determinant role  . The conflict in the Agoua case emerged when the project changed its discourse and announced the start of the implementation of the zoning plan. This discourse triggered frame shift to the local communities’ side and they started considering the project as negative. The local communities reacted to the discourse of the project by ex- pressing negative discourses, which reflected their new frames. In the case of the OSN forests, the conflict also emerged when the new forest rangers appointed held discourse about the institutional setting, which rejected the informal insti- tutions co-constructed by the former forest rangers and the local communities. The local communities in this case also made sense of this change in the dis- course held by the new forest rangers by constructing negative frames to charac- terize them, expressed it in their discourses and thus opposed to the change in roles and responsibilities. The conflict arose in the case of the PNP from the shift of the eco-guards’ frames about the park management directorate in reaction to their feeling that the park management directorate was not respecting its prom- ises concerning their career. The opposition of frames raised in this case from the lack of overt and clear communication between the park management direc- torate and the eco-guards about the needs and expectations of the eco-guards, what made this conflict a hidden one. The park management directorate consi- dered the eco-guards as exaggerating their needs whereas the eco-guards viewed the park management directorate as untrustworthy because it was not fulfilling its promises of the beginning towards them. So in all these cases, conflict arose in correlation with the shift of discourses held in the different interactional con- texts, which led to the shift in frames from positive to negative. The opposing discourses of both parties were constructed and held only in we-groups without bringing them to the fore to be discussed at meetings involving both parties.
19 Read more
Infections caused by Candida species is one of the major clinical threats in immunocompromised patients. Although, many antifungal drugs are currently in clinical practice, further novel antifungal drugs and new drug targets are in need due to the fear of antifungal drug resistance and re-emergence of infections. It has become imperative to understand the molecular mechanisms of drug resistance to combat the multidrug resistant fungal infections. Recently, many strategies are being implemented for the prevention of emergence of drug resistance in Candidal infections. Aggressive surveillance of resistance and development of appropriate protocol and guidelines for antifungal drug therapy is the major need today. Antifungal susceptibility testing in all cases is recommended for effective management of Candidal infections. Furthermore molecular, genetic and biological research is necessary to understand the underlying molecular drug resistance mechanisms in antifungal therapy and to discover newer antifungal drugs with high efficacy. Also, there is a need for integration of different disciplines in establishing the management protocol for Candidal infections. Furthermore, exploiting the diagnostic methods including the molecular techniques facilitates effective clinical management to reduce the morbidity and mortality due to candidal infections.
To minimize this phenomenon, however, resistance to change, managers could initiate a set of activities, such as preparation time change through discussions with those involved in this process, supporting and encouraging those involved in the process of change through effective participation in it, organizing debates on issues of change, interpersonal influence.
Psychology is a related domain for understanding the willingness and resistance aspects. This relates to understanding attitudes and behavior. In this domain of change management and psychology, Icek Azjen’s(1985) work on Theory of Planned Behavior is well acknowledged. In his model Azjen discusses the aspects of Attitude, Subjective Norm, Perceived behavior controls, Intention and behavior as the 5 aspects towards understanding the aspects of planned behavior. The DINAMO project (1997) conducted many experiments with Dutch police to validate this Azjen model towards understanding Willingness to change.The attitude has been studied in the areas of Cognition, Affect and Conation.
The advent of oncologic molecular typing has galvanized the discipline of personalized medicine. Recognition of common mutations within particular tumors has shown and holds tremendous promise for targeted individualized therapies. In melanoma, studies show an early favorable response to BRAF V600E inhibitors in treating BRAF V600E mutant melanomas. However, many challenges remain. The first and foremost is the other half of metastatic melanomas which do not harbor BRAF mutations. Another challenge is that although overall survival increases for those using BRAF inhibitors, complete resolution only occurs in a minor- ity and most cases relapse through secondary resistance. Other targeted therapies, such as tyrosine kinase inhibitors, are being explored in melanomas with activating c-KIT mutations, and therapies such as MEK inhibitors are being developed to exploit regulation of the MAPK pathway.
Organizational life is experienced as complex, frequently unexpected and ambiguous (Alvesson 2004, p.49). Yet managerialist and technocratic accounts tend to stress order and reasoned behaviour (Czarniawska 2003), privileging the perspective of “instrumental rationality” ie purposive, goal directed action (Watson 2002, p.81). Without denying the power and success of this perspective it does not really represent the fabric of social experience and it is precisely at this level the management task often occurs. Ambiguity stresses that there will always be multiple points of view. People will always operate within bounded rationality. Labelling different published accounts of events as stories acknowledges their ambiguity as claims about what happened. We know that stories are told from particular points of view and told for specific purposes. This opens up a focus on rhetorical character of discourse, with all its contradictions and evasions (Potter and Wetherell 1987) and allows us to hunt for the stories that are not told (Boje 2001, p.18).
15 Read more
Anticoagulants are a class of drugs commonly used to prevent the blood from forming dangerous clots that could result in a stroke. Warfarin is an oral anticoagulant. Warfarin differs from most other drugs in that the dosage required to achieve a desired therapeutic effect varies greatly among individuals. Resistance to warfarin has been described as the inability to prolong the prothrombin time or raise the international normalized ratio (INR) into the therapeutic range when the drug is given at normally prescribed doses. However, a higher warfarin requirement does not itself establish the diagnosis of warfarin resistance. Warfarin resistance can be classified as acquired versus hereditary. It can be diagnosed by laboratory studies and can be managed.