Use Of Control Strategies Research Articles

Resistance of Lepidopteran Egg Parasitoids, Trichogramma japonicum and Trichogramma chilonis, to Insecticides Used for Control of Rice Planthoppers.

Trichogramma wasps are commonly used as biocontrol agents to manage lepidopteran rice pests in rice fields. However, lepidopteran pests synergistically occur with rice planthoppers which are not targeted by Trichogramma. The use of Trichogramma parasitoids in field-based pest control efforts is greatly affected by the application of insecticides targeting planthoppers. As such, insecticide-resistant strains of Trichogramma are urgently needed for the incorporation of these beneficial natural enemies into integrated pest management programs in rice agroecosystems. In the present study, Trichogramma japonicum Ahmead (Hymenoptera: Trichogrammitidae) and Trichogramma chilonis Ishii (Hymenoptera: Trichogrammitidae) were treated with sublethal doses of four insecticides which target rice planthoppers, to generate tolerant strains in the laboratory. The resistance rate of T. japonicum to imidacloprid was the highest (17.8-folds) after 10 successive treatments and experienced 2.5, 4.72, and 7.41-fold increases in tolerance to thiamethoxam, buprofezin, and nitenpyram, respectively. Tolerance of T. chilonis to imidacloprid, thiamethoxam, buprofezin, and nitenpyram were 8.8, 6.9, 4.43, and 5.67-fold greater, respectively. The emergence and deformity (without spreading wings or short wings) rates of T. japonicum and T. chilonis gradually recovered with an increased exposure time of treatments. The fecundity of T. japonicum treated with thiamethoxam was significantly higher than that of the control and T. chilonis treated with thiamethoxam and nitenpyra. Our results demonstrate that screening for insecticide-tolerant/resistant Trichogramma strains was feasible, especially in the pairing of T. japonicum and imidacloprid, which could provide a valuable biological control tool that can be combined with traditional chemical control strategies for use in IPM of rice agroecosystems.

Organic Control Strategies for Use in IPM of Invertebrate Pests in Apple and Pear Orchards.

Simple SummaryReductions in the numbers of chemical plant protection products that are approved and a move towards organic production has changed the way growers produce fruit in Europe. This is likely the result of public pressure and the need for less reliance on broad-spectrum interventions. This review summarises organic approaches that could be adopted as part of integrated pest management strategies in apple and pear orchards. It focuses on control methods to target key and emerging European insect pests through biological, cultural, and physical control strategies. Growers of organic tree fruit face challenges in controlling some pests more easily suppressed by broad-spectrum insecticides in conventionally managed orchards. In recent decades, there has been a move towards organically growing varieties normally reliant on synthetic chemical pesticides (e.g., Gala), often to meet retailer/consumer demands. This inevitably makes crop protection in organic orchards more challenging, as modern varieties can be less tolerant to pests. In addition, there have been substantial reductions in plant protection product (PPP) approvals, resulting in fewer chemical options available for integrated pest management (IPM)-maintained orchards. Conversely, the organic management of fruit tree pests involves many practices that could be successfully implemented in conventionally grown crops, but which are currently not. These practices could also be more widely used in IPM-maintained orchards, alleviating the reliance on broad-spectrum PPP. In this review, we evaluate organic practices, with a focus on those that could be incorporated into conventional apple and pear production. The topics cover cultural control, biological control, physical and pest modifications. While the pests discussed mainly affect European species, many of the methods could be used to target other global pests for more environmentally sustainable practices.

Application of energy-saving control strategy in air conditioning terminal equipment based on constant temperature difference of chilled water

Effectively reducing the energy consumption of central air conditioning systems is an important aspect of building energy efficiency. The energy consumption of terminal equipment accounts for over 25% of that of air conditioning systems. Although the heat and moisture exchange mechanism of the terminal unit has been extensively studied, studies on control strategies for terminal unit operation are lacking. This study proposes an energy-saving optimization control strategy for terminal units based on the constant temperature difference of chilled water in an engineering application study. A fan coil unit (FCU) controller was designed and manufactured, and a Local Area Network (LAN) control system was constructed and compared to determine the optimal control strategy. When adopting the energy-saving optimization control strategy for the terminal unit based on a constant chilled water temperature difference, the energy consumption of the terminal equipment was significantly decreased by 7.2%. The flow rate of chilled water was reduced by 26.94% when the indoor air temperature requirements were met, effectively reducing the energy consumption of the central air-conditioning system. The adjustment time required to reach a stable indoor temperature was reduced and environmental comfort was improved. These results demonstrate the potential of this control strategy for use in engineering practices to replace traditional control modes.

Cost-Based Adaptive Droop Control Strategy for VSC-MTDC system

This study proposes a cost-based adaptive (CBA) droop control strategy for use in a voltage source converter (VSC)-based multi-terminal high voltage direct current (MTDC) system. Rather than using a fixed droop gain, we suggest the CBA droop control scheme, which reduces the total incremental generation cost of ac systems, while sharing the burden based on the available capacity of VSCs at the post-contingency-steady-state operating point. Following a certain VSC outage in the MTDC system, unbalanced power is allocated based on the equal incremental cost principle to reduce the total active power generation cost. The results were verified through a transient simulation on an MTDC system with four monopole VSCs, and outage contingency scenarios were presented with three groups of generation cost curves. The results indicate that the CBA droop control strategy can provide greater contributions to the economic operation of the MTDC system, while achieving robust control.

Laboratory and Greenhouse Evaluation of a Granular Formulation of Beauveria bassiana for Control of Western Flower Thrips, Frankliniella occidentalis.

Western flower thrips (WFT) is one of the most important pests of horticultural crops worldwide because it can damage many different crops and transmit various plant viruses. Given these significant impacts on plant production, novel methodologies are required to maximize regulation of WFT to minimize crop losses. One particular approach is to develop control strategies for the non-feeding, soil-dwelling stages of WFT. Control of these stages could be enhanced through the use of granules impregnated with entomopathogenic fungi mixed in the soil. The use of soil-applied fungi contrasts with existing approaches in which entomopathogenic fungi are formulated as oil-based suspensions or water-based wettable powders for foliar applications against the feeding stages of WFT. To examine the efficacy of this approach, we evaluated the effects of a granular formulation of Beauveria bassiana on the soil-dwelling, pupal phases of Frankliniella occidentalis in laboratory bioassays and greenhouse experiments. Based on micromorphological observations of fungal conidia during the infection process after treatment of WFT with a B. bassiana suspension, fungal conidia complete the process of surface attachment, germination, and penetration of the body wall of the WFT pupa and enter the host within 60 h of treatment. Given these results, we undertook a controlled greenhouse experiment and applied B. bassiana granules to soil used to cultivate eggplants. Populations of F. occidentalis on eggplants grown in treated soil were 70% lower than those on plants grown in the untreated soil after 8 weeks. Furthermore, when measuring the survival and growth of B. bassiana on granules under different soil moisture conditions, survival was greatest when the soil moisture content was kept at 20%. These results indicate that the application of B. bassiana-impregnated granules could prove to be an effective biological control strategy for use against F. occidentalis under greenhouse conditions.

Gastrointestinal Parasites in Shelter Dogs: Occurrence, Pathology, Treatment and Risk to Shelter Workers.

Simple SummaryDespite evidence of a minor role of gastrointestinal parasites in causing disease in owned pet populations prophylactically treated with anthelmintics, gastrointestinal parasitism remains an important consideration in the care of animals in shelters, and in owned pet populations in developing countries, where regular prophylactic treatment is lacking. In addition, the zoonotic potential of many organisms is a universal public health concern. Animal shelters facilitate spread of gastrointestinal parasites to incoming animals and shelter staff if there is overcrowding and frequent exposure to a contaminated environment. The prevalence of gastrointestinal parasites in shelter dogs is typically higher than in owned dogs. In this review, we report the prevalence of parasites in shelter dogs worldwide, and review parasite control strategies for use in shelters. We also discuss whether the shelter environment might magnify risks for development of parasiticide resistance in resident parasite populations. We recommend an integrated parasite control approach based on sanitation measures to reduce environmental contamination and accompanied with appropriate use of anthelmintics in shelter dogs. Ideally, every animal should be treated after fecal examination for parasites during its stay in the shelter, although it is recognized that for many shelters, the resources to do this might be prohibitive.Dogs entering shelters can carry gastrointestinal parasites that may pose serious risks to other animals, shelter staff and visitors. Shelters provide an environment that could facilitate the spread of parasitic infections between animals. Nematodes and protozoa that transmit through ingestion or skin penetration are major enteric parasites of concern in shelter settings. Ancylostoma spp., Uncinaria stenocephala, Toxocara canis, Toxascaris leonina, Trichuris vulpis and Dipylidium caninum are the major helminths while Giardia, Cryptosporidium, Isospora spp. and Sarcocystis spp. are the most prevalent protozoan parasites in shelter dogs. The prevalence of gastrointestinal parasites in shelter dogs is typically higher than in owned dogs. A range of cost-effective drugs is available for prevention and control of helminths in shelters, notably fenbendazole, pyrantel, oxantel, and praziquantel. Parasiticide options for protozoan parasites are often cost-prohibitive or limited by a lack of veterinary registration for use in dogs. Environmental control measures reliant upon hygiene and facility management are therefore a mainstay for control and prevention of protozoan parasites in shelters. This philosophy should also extend to helminth control, as integrated parasite control strategies can allow anthelmintics to be used more sparingly and judiciously. The purpose of this article is to comprehensively review the current knowledge on the prevalence of gastrointestinal parasites most commonly found in dogs in shelters, canvass recommended treatment programs in shelter dogs, and to explore the likelihood that parasiticide resistance might emerge in a shelter environment.

57 Take Charge of Burn Pain: Development and Feasibility

Burn related pain is a common experience post‐injury impacting physical, psychological and social recovery, and reducing long‐term function and community participation. While there have been extensive efforts to develop acute pain control strategies for use during the hospitalization phase of burn care, and self‐management pain management approaches have proven efficacy in other painful conditions, self‐management strategies for managing chronic pain due to burn injury have not been developed or tested. The goals of this project are to develop, and evaluate the efficacy of pain self-management, web‐based intervention, using an RCT design. This paper reports on the development of the program and provides data on the initial feasibility and acceptability. The the Take Charge of Burn Pain online self-management program (www.takechargeofburnpain.org) was developed in conjunction with the Phoenix Society, using a participatory action research model. This process resulted in a cognitive-behavioral based, 7 session, interactive program that utilizes the principles of self-management to provide knowledge, self-monitoring, pain coping skill development and practice. In the RCT, persons with burn related pain are randomized to standard care plus web-based education attention control) or standard care plus the TCB-Pain web-based self- management pain intervention. Patient reported outcomes are gathered via web-based questionnaires at baseline, 2 months and 5 month follow-up. Eligibility criteria are: 18 to 70 years of age, having experienced a burn injury requiring hospitalization at least 6 months prior to enrollment; 2) Reporting a pain severity score on the Brief Pain inventory of 4 (0‐10) or higher; 3) Reporting pain of at least 3 months duration; and 4) English speaking. The 108 participants are 56.5% female, 70% white, 14% Latino/Hispanic, 76% have more than high school education, and a mean age of 43. At program completion participants report high levels of satisfaction with the program (86% reported benefits equal or exceed effort put into the program). Of the 108 participants that have been enrolled 28 (26%) have not started the program and 12 (11%) inactive and 64 (60%) have completed. Participants report high levels of satisfaction with the program and perceive benefits at program completion. There are significant numbers of individuals who enroll in the program and do not complete. Additional research is needed to identify methods to enhance program completion and determine the long term impact on pain, pain interference, distress and quality of life. The Take Charge of Burn Pain program is designed to be part of a multi-modal pain program by providing an accessible, web‐based system, to develop evidenced‐based pain self‐management skills.

Avian Interferon-Inducible Transmembrane Protein Family Effectively Restricts Avian Tembusu Virus Infection.

Avian Tembusu virus (ATMUV) is a highly pathogenic flavivirus that causes significant economic losses to the Chinese poultry industry. Our previous experiments demonstrated that ATMUV infection effectively triggered host innate immune response through MDA5 and TLR3-dependent signaling pathways. However, little information is available on the role of interferon-stimulated genes (ISGs) in defending against ATMUV infection. In this study, we found that ATMUV infection induced robust expression of type I and type III interferon (IFNs) in duck tissues. Furthermore, we observed that expression of interferon-inducible transmembrane proteins (IFITMs) was significantly upregulated in DEF and DF-1 cells after infection with ATMUV. Similar results were obtained from in vivo studies using ATMUV-infected ducklings. Importantly, we showed that knockdown of endogenous IFITM1 or IFITM3 by specific shRNA markedly enhanced ATMUV replication in DF-1 cells. However, disruption of IFITM2 expression had no obvious effect on the ATMUV replication. In addition, overexpression of chicken or duck IFITM1 and IFITM3 in DF-1 cells impaired the replication of ATMUV. Taken together, these results reveal that induced expression of avian IFITM1 and IFITM3 in response to ATMUV infection can effectively restrict the virus replication, and suggest that increasing IFITM proteins in host may be a useful strategy for control of ATMUV infection.

Wind Energy Conversion System for Rural Application

This paper presents the use of induction generator with suitable control strategy for use as standalone wind energy conversion system. This may find application in remote rural areas where extension of 11 kV feeder may not be feasible due to physical terrain and where drawing of line may not be economically viable if loads are dispersed over wide area. This Induction machine is driven from a prim em over which is usually a wind turbine. The stator terminals of the induction machine is connected to a voltage source converter. The voltage source converter (VSC) is a three level diode clamped VSC. The terminals of the converter are connected to a capacitor and a battery. The battery is initially charged to 12 V and provides initial magnetisation for the Induction Generator. The terminals of the stator are also connected to an induction motor represented by RL load. Control strategy has been developed to keep the DC voltage constant irrespective of variation of load and rotor speeds. The total harmonic distortion in the line voltage of the induction machine is ensured to be within limits by employing three level converter. The proposed system is mathematically modelled using SIMULINK/MATLAB. The simulated results validate the theory studied.

Onboard screening dockside testing as a new means of managing paralytic shellfish poisoning risks in federally closed waters

Paralytic shellfish poisoning (PSP) is the foodborne intoxication associated with the consumption of seafood contaminated with naturally occurring neurotoxins known as paralytic shellfish toxins. To protect public health from this potentially fatal syndrome, harvesting closures are implemented when toxins exceed the regulatory action level. Traditional monitoring programs established by state shellfish authorities allow for timely closures in state waters with minimal negative impacts on industry. However, such monitoring programs are not feasible in federal offshore waters given their distance from shore and the range of their spatial coverage. Thus innovative management strategies were investigated for these offshore resources. Georges Bank, an offshore resource with an estimated market value of more than $3 billion in Atlantic surfclams and ocean quahogs, has been closed to harvesting following a temporary ban in 1989 and a subsequent indefinite closure in 1990 due to the risk of PSP. As a means of managing this risk and allowing harvest of safe shellfish from this important resource, the Onboard Screening Dockside Testing Protocol (referred to as the Protocol) was developed by the US Food and Drug Administration (FDA), National Marine Fisheries Service (NMFS), state shellfish control authorities, and industry. The Protocol, which sets forth control measures to ensure product safety and public health protection, was endorsed by the Interstate Shellfish Sanitation Conference (ISSC) for pilot testing. Briefly, the pilot study Protocol required that (1) the fishing vessel receive a permit from NMFS to harvest in closed waters, (2) a minimum of five shellfish samples per intended harvest lot be tested for PSP toxins onboard, and (3) harvesting only occur when the samples tested from the intended fishing area are negative using the Jellett Rapid Tests or Abraxis Shipboard ELISA kits. Finally, product landed under the Protocol was confirmed to be safe for consumption using the mouse bioassay (MBA) prior to its introduction into commerce. This paper presents data from the pilot study, with primary focus on the advantages and challenges of the field kits employed onboard compared to the dockside MBA, which has served as the longstanding regulatory method for PSP toxins. In 2010 alone, the successful pilot study resulted in the safe harvest of over $2.7 million worth of surfclams in an area that has otherwise been unavailable for decades. Due to the success of this pilot study, the Protocol was adopted into the National Shellfish Sanitation Program Model Ordinance as an approved marine biotoxin control strategy for use in federal waters at the 2011 ISSC Biennial Meeting. In January 2013 a portion of Georges Bank was reopened for the harvest of Atlantic surfclams and ocean quahogs to fishermen following the Protocol.

Evaluation of GeneXpert® system for detection of methicillin-resistant Staphyloccocus aureus in clinical samples

Infections caused by methicillin-resistant Staphyloccocus aureus strains (MRSA) have reached epidemic proportions globally, being the major cause of nosocomial infections. Rapid identification of MRSA in nasal swabs or in clinical samples is considered a useful strategy for control and treatment of these infections. GeneXpert system (Cepheid Europe,Vira-Solelch, Maurence-Scopont-France) can detect by real-time PCR in approximately one hour methicillin-resistant S. aureus or coagulase-negative staphylococci (CoNS) in clinical samples, in comparison with 24 hours for the culture or 48 hours for the antimicrobial susceptibility testing. In this study GeneXpert system was compared with traditional tests for MRSA detection in nasal swabs, bloodcultures and surgical wound swabs. Materials and methods. Eighteen nasal swabs, 23 blood-cultures and 13 surgical wound swabs were tested. The samples were cultured on blood-agar and mannitol-salt agar. Identification of isolates was carried out with traditional tests (Gram staining, catalase, coagulase) and automatic Phoenix system. Methicillin-susceptibility was evaluated according to 2010 CLSI guidelines. GeneXpert system was performed according to manufacturers instructions, by using the specific kits and methicillin-resistance was detected by amplification of the genic sequences spa, SCC e mecA. Results. The results showed a 100% accordance between GeneXpert system and traditional tests for detection of methicillin-resistant staphylococci. In particular, among 18 nasal swabs, no MRSA was detected, while 1 bloodculture (4.3%) and 4 surgical wound swabs (30.7%) were positive for MRSA. Conclusions. GeneXpert system allows a rapid detection of MRSA in clinical samples and shows the same sensitivity and specificity as traditional tests. Therefore, it represents a further effective diagnostic method for prevention and treatment of nosocomial infections due to methicillin-resistant staphylococci.

BRAHMS: Novel middleware for integrated systems computation

Biological computational modellers are becoming increasingly interested in building large, eclectic models, including components on many different computational substrates, both biological and non-biological. At the same time, the rise of the philosophy of embodied modelling is generating a need to deploy biological models as controllers for robots in real-world environments. Finally, robotics engineers are beginning to find value in seconding biomimetic control strategies for use on practical robots. Together with the ubiquitous desire to make good on past software development effort, these trends are throwing up new challenges of intellectual and technological integration (for example across scales, across disciplines, and even across time) – challenges that are unmet by existing software frameworks. Here, we outline these challenges in detail, and go on to describe a newly developed software framework, BRAHMS, that meets them. BRAHMS is a tool for integrating computational process modules into a viable, computable system; its generality and flexibility facilitate integration across barriers, such as those described above, in a coherent and effective way. We go on to describe several cases where BRAHMS has been successfully deployed in practical situations. We also show excellent performance in comparison with a monolithic development approach. Additional benefits of developing in the framework include source code self-documentation, automatic coarse-grained parallelisation, cross-language integration, data logging, performance monitoring, and will include dynamic load-balancing and ‘pause and continue’ execution. BRAHMS is built on the nascent, and similarly general purpose, model markup language, SystemML. This will, in future, also facilitate repeatability and accountability (same answers ten years from now), transparent automatic software distribution, and interfacing with other SystemML tools.

Beyond Our Pages

Beyond Our Pages

IMAGING AND CONTROL FOR ADAPTIVE RADIOTHERAPY

This paper reviews existing techniques to deliver radiotherapy treatment and describes the requirements from a control engineering view point to adapt radiation delivery to organs motion. The first part describes recent evolution of radiotherapy research; the second part focuses on imaging modalities used in radiotherapy; the third part reviews image processing techniques to detect organ movement; the final section compares traditional PID with predictive control strategies for use in patient positioning devices.

Adaptive traffic control system: Control strategy, prediction, resolution, and accuracy

AbstractRecent advances in traffic control methods have led to flexible control strategies for use in an adaptive traffic control system (ATCS). ATCS aims at controlling the imminent traffic, which is yet to arrive and hence not known perfectly. Therefore, volume prediction is an essential part. Associated with the prediction are two aspects: resolution and accuracy. Recent studies indicate a tradeoff between prediction resolution and accuracy: finer resolutions, larger errors. It is imperative to study the relationship and tradeoff between the control strategy, prediction resolution, and its associated error, which are crucial to the development of ATCS. This study investigates this relationship through an extensive simulation of scenarios in Hong Kong with a recently developed dynamic traffic control model, DISCO. Based on the Hong Kong scenarios conducted with DISCO, the major findings include: (i) the importance of resolution outweighs that of error; (ii) dynamic timing plans generally outperform time‐invariant timing plans; (iii) up to a certain extent, overestimated predictions lead to better results than underestimated predictions.

Impact and Control of Forest Diseases in Canada

For the period 1977-1981, estimates of annual timber losses in Canada as a result of disease are 65 million m3. Intensive forest management presents an opportunity for utilizing pathological recommendations for reducing these losses in order to maintain forest productivity. Control of nursery diseases, root rot, dwarf mistltoes, and Dutch elm disease has been most successful. The accuracy of net inventory volume has been greatly improved. There is a need to develop more reliable surveys for loss estimates and to predict future fosses, particularly on an individual stand basis. The utilization of biological information to develop new control strategies for use in intensive forest management is a challenge facing forest pathologists and forest managers in Canada today.

Direct Flux and Torque Regulation in a PWM Inverter-Induction Motor Drive

A dc motor drive is controlled by varying the armature current and field current. The field is a measure of flux, and the armature current times field current is a measure of torque. Various approximate means of estimating the flux and torque levels in an induction motor exist. Most of these methods are sensitive to motor parameter value changes and do not work well near zero speed. Also, the harmonics in the motor voltage and current due to the nonsinusoidal inverter waveform cause errors in the estimated torque. A practical method has been developed to measure the flux level in an induction motor in the actual operating environment. Using the flux signals and stator current, the actual electromagnetic torque can be obtained. This torque signal responds correctly to motor saturation and inverter voltage waveform harmonics. The motor can be designed to operate without the customarily required flux margin, since the flux level is accurately controlled. The control strategy for use with these feedback signals does not require the use of a tachometer.

A Comparison of Learner Control and Machine Control Strategies for Computer‐Assisted Instruction

A learner control strategy for use in CAI sequences is presented and is compared to a machine control strategy. The procedure followed was to write two sequences to introduce students to the language and functional design of the CLIP computer; one employing each strategy. The sequences were taken by 26 students, after which they were examined on the content and answered attitude questionnaires. An important result of this investigation is that students taking the sequence with the strategy of learner control, learn as much as students using the machine control strategy; they also retain most of what they learn, whereas students taking the machine controlled sequence forget a significant amount after two weeks. Furthermore, they appear to have a slightly more favourable attitude to their lessons.