Impact of control strategies on bellyache bush (Jatropha gossypiifolia L.) mortality, seedling recruitment, population dynamics, pasture yield and cost analysis

2011 ◽  
Vol 33 (3) ◽  
pp. 277 ◽  
Author(s):  
Faiz F. Bebawi ◽  
Joseph S. Vitelli ◽  
Shane D. Campbell ◽  
Robert J. Mayer
Keyword(s):  
Best Practice ◽  
Seedling Recruitment ◽  
Control Strategies ◽  
Cost Effective ◽  
Effective Control ◽  
Invasive Weed ◽  
Population Demographics ◽  
Jatropha Gossypiifolia ◽  
Pasture Yield

Bellyache bush (Jatropha gossypiifolia L.) is an invasive weed that has the potential to greatly reduce biodiversity and pasture productivity in northern Australia’s rangelands. This paper reports an approach to develop best practice options for controlling medium to dense infestations of bellyache bush using combinations of control methods. The efficacy of five single treatments including foliar spraying, slashing, stick raking, burning and do nothing (control) were compared against 15 combinations of these treatments over 4 successive years. Treatments were evaluated using several attributes, including plant mortality, changes in population demographics, seedling recruitment, pasture yield and cost of treatment. Foliar spraying once each year for 4 years proved the most cost-effective control strategy, with no bellyache bush plants recorded at the end of the study. Single applications of slashing, stick raking and to a lesser extent burning, when followed up with foliar spraying also led to significantly reduced densities of bellyache bush and changed the population from a growing one to a declining one. Total experimental cost estimates over 4 successive years for treatments where burning, stick raking, foliar spraying, and slashing were followed with foliar spraying were AU$408, AU$584, AU$802 and AU$789 ha–1, respectively. Maximum pasture yield of 5.4 t ha–1 occurred with repeated foliar spraying. This study recommends that treatment combinations using either foliar spraying alone or as a follow up with slashing, stick raking or burning are best practice options following consideration of the level of control, changes in pasture yield and cost effectiveness.

scholarly journals Genetic Variations in Bionomics of Culex quinquefasciatus (Diptera: Culicidae) Mosquito Population in Minna, North Central Nigeria

2016 ◽  
Vol 8 ◽  
pp. IJIS.S32516 ◽  
Author(s):  
Azubuike C. Ukubuiwe ◽  
Israel K. Olayemi ◽  
Aisha I. Jibrin
Keyword(s):  
Culex Quinquefasciatus ◽  
Control Strategies ◽  
Preliminary Investigation ◽  
Cost Effective ◽  
Immature Stage ◽  
Effective Control ◽  
Mosquito Vector ◽  
North Central ◽  
Mosquito Vector Control ◽  
Vectorial Competence

The need to have an improved knowledge on the bioecology of Culex quinquefasciatus, a prerequisite in the development of cost-effective control strategies, has informed the present preliminary investigation to put in better perspective variations that exist in the egg rafts of the species. Freshly laid egg rafts were collected and incubated at ambient temperature in well-labeled plastic trays. The results showed overall inconsistency in all indices monitored for the egg rafts. Generally, survivorship was high for the species. All immature stage and adult parameters measured varied significantly among the egg rafts and between/within sexes of the species. Therefore, this study suggests the presence of inherent variation in the bionomics of egg rafts of C. quinquefasciatus, probably influenced by the environment and hence underscores the need for additional studies to further elucidate the roles of genetics and environment in vectorial competence of the species, in order to develop robust sustainable mosquito vector control protocols.

scholarly journals Prevention of Influenza Pandemic by Multiple Control Strategies

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Roman Ullah ◽  
Gul Zaman ◽  
Saeed Islam
Keyword(s):  
Optimal Control ◽  
Control Strategies ◽  
Influenza Pandemic ◽  
Antiviral Treatment ◽  
Cost Effective ◽  
Effective Control ◽  
Numerical Techniques ◽  
Multiple Control ◽  
Control Functions ◽  
Transmission Of Disease

We present the prevention of influenza pandemic by using multiple control functions. First, we adjust the control functions in the pandemic model, then we show the existence of the optimal control problem, and, by using both analytical and numerical techniques, we investigate cost-effective control effects for the prevention of transmission of disease. To do this, we use four control functions, the first one for increasing the effect of vaccination, the second one for the strategies to isolate infected individuals, and the last two for the antiviral treatment to control clinically infectious and hospitalization cases, respectively. We completely characterized the optimal control and compute the numerical solution of the optimality system by using an iterative method.

Modeling Population Dynamics of Kochia (Bassia scoparia) in Response to Diverse Weed Control Options

Weed Science ◽  
2019 ◽  
Vol 67 (1) ◽  
pp. 57-67 ◽  
Author(s):  
O. Adewale Osipitan ◽  
J. Anita Dille ◽  
Muthukumar V. Bagavathiannan ◽  
Stevan Z. Knezevic
Keyword(s):  
Population Dynamics ◽  
Population Growth ◽  
Weed Control ◽  
Seed Production ◽  
Seedling Recruitment ◽  
Control Strategies ◽  
Effective Control ◽  
Parameter Estimates ◽  
Herbicide Resistant

AbstractKochia [Bassia scoparia(L.) A. J. Scott] is a problematic weed species across the Great Plains, as it is spreading fast and has developed herbicide-resistant biotypes. It is imperative to understand key life-history stages that promote population expansion ofB. scopariaand control strategies that would provide effective control of these key stages, thereby reducing population growth. Diversifying weed control strategies has been widely recommended for the management of herbicide-resistant weeds. Therefore, the objectives of this study were to develop a simulation model to assess the population dynamics ofB. scopariaand to evaluate the effectiveness of diverse weed control strategies on long-term growth rates ofB. scopariapopulations. The model assumed the existence of a glyphosate-resistant (GR) biotype in theB. scopariapopulation, but at a very low proportion in a crop rotation that included glyphosate-tolerant corn (Zea maysL.) and soybean [Glycine max(L.) Merr.]. The parameter estimates used in the model were obtained from various ecological and management studies onB. scoparia. Model simulations indicated that seedling recruitment and survival to seed production were more important than seedbank persistence forB. scopariapopulation growth rate. Results showed that a diversified management program, including glyphosate, could provide excellent control ofB. scopariapopulations and potentially eliminate already evolved GRB. scopariabiotypes within a given location. The most successful scenario was a diverse control strategy that included one or two preplant tillage operations followed by preplant or PRE application of herbicides with residual activities and POST application of glyphosate; this strategy reduced seedling recruitment, survival, and seed production during the growing season, with tremendous negative impacts on long-term population growth and resistance risk inB. scoparia.

scholarly journals Nosocomial infections in neonatal intensive care units: Cost-effective control strategies in resource-limited countries

2013 ◽  
Vol 40 (2) ◽  
pp. 125-132
Author(s):  
SN Uwaezuoke ◽  
HA Obu
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Hand Hygiene ◽  
Neonatal Intensive Care Unit ◽  
Nosocomial Infections ◽  
Neonatal Intensive Care ◽  
Control Strategies ◽  
Cost Effective ◽  
Effective Control ◽  
Resource Limited

Background: Nosocomial infections or hospital-acquired infectionsconstitute a global health problem. They lead to significant morbidity and mortality in both developed and resource-limited countries. The neonatal intensive care unit (NICU) is a suitable environment for disseminating these infections; underscoring the need for preventive intervention measures.Objectives: This review aims to highlight the global burden of nosocomialinfections in neonatal intensive care units (NICUs), to discuss their epidemiology and clinical spectrum, as well as the costeffective control strategies in resource-limited settings.Sources: Sources of information were from Google searches andPubMed- linked articles using the key words- nosocomial infections,neonatal intensive care unit, control. Related articles from hard copiesof medical literature and journals were also gathered.Results: Although paucity of data exists on the incidence of nosocomialinfections in NICUs in developing countries, reports from developedcountries indicate a range of 6% to 25%. Much higher figures were noted in some developing countries. Several risk factors for nosocomial infections were identified but varied in different NICUs surveyed. Effective control strategies have been recommended but hand washing or hand hygiene appears universally applicable in both developed and resource-limitedcountries. Economic analyses of these strategies in developed countrieshave established their costeffectiveness while the adaptability of hand hygiene program to resource-limited settings has been demonstrated in a World Health Organization pilot study in sub- Saharan Africa.Conclusion: Hand washing or hand hygiene by health-care personnelremains the most important evidence-based and cost-effective controlstrategy for the spread of nosocomial infections in NICUs in resource-limited countries.Key words: nosocomial infections; neonatal intensive care unit;control.

The role of non-toxic prefeed and postfeed in the development and maintenance of 1080 bait shyness in captive brushtail possums

2000 ◽  
Vol 27 (1) ◽  
pp. 69 ◽  
Author(s):  
J. G. Ross ◽  
G. J. Hickling ◽  
D. R. Morgan ◽  
C. T. Eason
Keyword(s):  
Cost Effective ◽  
Effective Control ◽  
Trichosurus Vulpecula ◽  
Control Operation ◽  
Control Option

Shyness to sodium monofluoroacetate (1080) in cereal bait can persist in sub-lethally poisoned possum (Trichosurus vulpecula) populations for at least 2 years. We investigated the use of non-toxic cereal ‘prefeed’ and ‘postfeed’ as ways of inhibiting and overcoming such shyness. The postfeed result was also compared with changing to a non-cereal, gel-based 1080 bait. Prefeeding had a significant effect on the number of possums that became ‘bait shy’ following an approximate LD20 1080 dose, with 97% of non-prefed possums developing an aversion to 1080 cereal bait compared with only 22% of prefed possums. In contrast, postfeeding with cereal was relatively ineffective in reducing the number of 1080 bait-shy possums, with mortality of these possums being 30% compared with 0% of non-postfed possums. In contrast, the gel 1080 bait killed 64% of 1080 cereal bait-shy possums. These results suggest that 1080 bait shyness can be markedly reduced by prefeeding non-toxic bait to possums prior to each control operation. However, this may not be the most cost-effective control option, given the observed efficacy of follow-up baiting with 1080 gel.

Benefits and feasibility of local elimination of possum populations

2006 ◽  
Vol 33 (7) ◽  
pp. 605 ◽  
Author(s):  
D. R. Morgan ◽  
G. Nugent ◽  
B. Warburton
Keyword(s):  
Control Strategies ◽  
Cost Effective ◽  
Population Characteristics ◽  
Effective Control ◽  
Brushtail Possum ◽  
Control Approach ◽  
Initial Cost ◽  
Regulatory Status ◽  
The Cost

Introduction of the brushtail possum (Trichosurus vulpecula) to New Zealand has resulted in serious ecological and economic impacts and considerable control efforts. Recovery of possum populations after control occurs through immigration from adjacent areas and breeding of survivors and immigrants. If complete local elimination can be achieved, the recovery of populations will depend solely on immigration and therefore should be substantially slowed (particularly in very large areas). To compare the cost-effectiveness of four control strategies over the long term (60 years), we constructed a deterministic bioeconomic model based on 23 variables describing population characteristics, sizes of the sink (i.e. area controlled) and source (of reinfestation) areas, and costs. Sensitivity analysis showed that the most influential variables related primarily to cost and effectiveness of control, whereas factors describing immigration after control had relatively little influence. When the most influential variables were varied, the model predicted that local elimination of possums followed by ‘perimeter’ control is likely to be a more cost-effective control strategy under most scenarios than the current ‘knockdown-then-maintenance-control’ approach. Possum-control technology and its application have improved greatly in the last three decades such that it now appears that local elimination is, technically, a realistic goal, and is possibly already being achieved occasionally. Constraining factors include unreliable monitoring/detection at ultralow densities, inappropriate selection and use of control options, lack of incentive under the present contracting system, initial cost, contracting capacity, and the future regulatory status of poisons. However, these difficulties can be overcome, facilitating the adoption of long-term local elimination strategies that are better suited to managing possum populations in perpetuity.

scholarly journals Multiple Control Strategies for Prevention of Avian Influenza Pandemic

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Roman Ullah ◽  
Gul Zaman ◽  
Saeed Islam
Keyword(s):  
Optimal Control ◽  
Avian Influenza ◽  
Control Strategies ◽  
Influenza Pandemic ◽  
Antiviral Treatment ◽  
Cost Effective ◽  
Effective Control ◽  
Multiple Control ◽  
Control Functions ◽  
The Cost

We present the prevention of avian influenza pandemic by adjusting multiple control functions in the human-to-human transmittable avian influenza model. First we show the existence of the optimal control problem; then by using both analytical and numerical techniques, we investigate the cost-effective control effects for the prevention of transmission of disease. To do this, we use three control functions, the effort to reduce the number of contacts with human infected with mutant avian influenza, the antiviral treatment of infected individuals, and the effort to reduce the number of infected birds. We completely characterized the optimal control and compute numerical solution of the optimality system by using an iterative method.

scholarly journals Ventilator-associated pneumonia among ICU patients in WHO Southeast Asian region: A systematic review

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247832
Author(s):  
Sanjeev Kharel ◽  
Anil Bist ◽  
Shyam Kumar Mishra
Keyword(s):  
Antibiotic Resistance ◽  
Control Strategies ◽  
Health Resources ◽  
Cost Effective ◽  
Effective Control ◽  
Ventilator Associated Pneumonia ◽  
Asian Region ◽  
The World ◽  
Limited Health ◽  
Gram Negative Organisms

Ventilator-associated pneumonia (VAP) is one of the most frequent ICU-acquired infections and a leading cause of death among patients in Intensive Care Unit (ICU). The South East Asian Region is a part of the world with limited health resources where infectious diseases are still underestimated. We aimed to review the literature in this part of the world to describe incidence, mortality and microbiological evidence of VAP and explore preventive and control strategies. We selected 24 peer-reviewed articles published from January 1, 2000 to September 1, 2020 from electronic databases and manual searching for observational studies among adult patients diagnosed with VAP expressed per thousand days admitted in ICU. The VAP rates ranged from 2.13 to 116 per thousand days, varying among different countries of this region. A significant rate of mortality was observed in 13 studies ranging from 16.2% to 74.1%. Gram negative organisms like Acinetobacter spp., Pseudomonas aeruginosa and Klebsiella pneumoniae and Gram-positive organisms like Staphylococcus aureus and Enterococcus species were frequently found. Our findings suggest an alarming situation of VAP among patients of most of the countries of this region with increasing incidence, mortality and antibiotic resistance. Thus, there is an urgent need for cost effective control and preventive measures like interventional studies and educational programs on staff training, hand hygiene, awareness on antibiotic resistance, implementation of antibiotic stewardship programs and appropriate use of ventilator bundle approach.

scholarly journals Jubatagrass (Cortaderia jubata) Control Using Chemical and Mechanical Methods

2008 ◽  
Vol 1 (1) ◽  
pp. 82-90 ◽  
Author(s):  
Joseph M. DiTomaso ◽  
Jennifer J. Drewitz ◽  
Guy B. Kyser
Keyword(s):  
Seedling Recruitment ◽  
Cost Effective ◽  
High Volume ◽  
Early Summer ◽  
Effective Control ◽  
Native Plant ◽  
Mechanical Removal ◽  
Mechanical Methods ◽  
Low Volume ◽  
Herbicide Control

AbstractJubatagrass is one of the most invasive plants along the California and southern Oregon coast. It establishes dense populations that can severely impact native plant diversity and conifer seedling recruitment following forestry operations. This goal of this study was to evaluate the effectiveness of both manual removal and several herbicide control options and application techniques. In addition, a cost analysis was also conducted for the most successful herbicide control methods. Results demonstrate that mechanical removal through digging is effective, although labor intensive. Among the herbicides tested, glyphosate applied as a high-volume (spray-to-wet) application (0.6% ae) in early summer, low-volume application (2.4% ae) in early summer or fall, and ropewick technique in early summer or fall (> 9.9% ae) all provided ≥ 88% jubatagrass control, but the low-volume treatments were the most cost effective. Although the graminicide sethoxydim at the highest rate (0.36% ai) did not give effective control, fluazifop applied in the fall in a low-volume treatment (0.98% ai) gave 87% control of jubatagrass. Imazapyr gave some level of control but does not appear to provide an economical option for jubatagrass management. Results of this study demonstrate that in addition to the more conventional methods of mechanical removal and spray-to-wet glyphosate (0.6% ae), control of jubatagrass can also be equally or more effective with low-volume and ropewick applications of glyphosate.

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