Thermal stress causes nuclear and cellular abnormalities of peripheral erythrocytes in Indian major carp, rohu Labeo rohita.

Rise of water temperature as a consequence of global warming is anticipated to affect the physiological activities of fish, especially in tropical regions. In the present experiment, we exposed the Indian major carp, rohu Labeo rohita to three different temperature regimes (30 °C as control and 33 °C and 36 °C) for 60 days and observed the effects of these temperature on: major hemato-biochemical indices (Hemoglobin; Hb, Red blood cell; RBC, White blood cell; WBC and blood glucose levels), erythrocytic nuclear abnormalities (ENA), and erythrocytic cellular abnormalities (ECA) of peripheral erythrocytes along with the formation of differential leucocytes in the blood. Fish were sacrificed at day 7, 15, 30 and 60 after the start of exposure to the temperature regimes. Hb decreased significantly on days 7 and 15 at 36 °C. Throughout the study period, the decrease of RBC and increase of WBC were significant at 36 °C. Blood glucose level increased significantly initially at day 7 but decreased significantly at day 60 at 36 °C. Frequencies of ENA (binucleated, nuclear bud, nuclear bridge, karyopyknosis and notched nuclei) and ECA (twin, fusion, echinocytic, spindle, tear drop and elongated shaped) were significantly increased at the highest temperature (36 °C) at almost all of the sampling days. In the case of differential leucocyte count, high temperature caused a significant increase in the number of neutrophils and a significant decrease in the number of lymphocytes. Overall, these results indicate that chronic exposure to high temperature (36 °C) induces a number of stress responses in rohu and that temperature should be kept below 36 °C in the aquaculture setting to avoid damage to the fish.

Sensitivity of Phacidiopycnis spp. Isolates from Pome Fruit to Six Pre- and Postharvest Fungicides.

Phacidiopycnis washingtonensis and P. pyri cause speck rot and Phacidiopycnis rot on apple and pear, respectively. Infection occurs in the orchard and remains latent, and symptoms appear after months of storage. Decay management relies on orchard sanitation and pre- and postharvest fungicides. In a 2017 survey, speck rot accounted for 6.4% of apple decay in central Washington, whereas Phacidiopycnis rot accounted for 3.9 and 6.7% of total pear decay in Washington and Oregon, respectively. Sensitivities of baseline populations of 110 P. washingtonensis and 76 P. pyri isolates collected between 2003 and 2005 to preharvest fungicides pyraclostrobin (PYRA) and boscalid (BOSC) and to postharvest fungicides thiabendazole (TBZ), fludioxonil (FDL), pyrimethanil (PYRI), and difenoconazole (DFC) were evaluated using a mycelial growth inhibition assay. Mean effective concentrations necessary to inhibit 50% growth (EC50) of P. washingtonensis were 0.1, 0.3, 0.8, 1.8, 2.1, and 4.8 µg/ml for FDL, PYRI, TBZ, DFC, PYRA, and BOSC, respectively. Respective mean EC50 values for P. pyri were 0.2, 0.6, 1.6, 1.1, 0.4, and 1.8 µg/ml. The sensitivity of exposed P. washingtonensis and P. pyri populations collected in 2017 revealed potential shifts toward BOSC and PYRA resistance. The efficacy of the six fungicides to control isolates of each pathogen with different in vitro sensitivity levels was evaluated on apple and pear fruit. FDL, DFC, and PYRI controlled both Phacidiopycnis spp. regardless of their EC50 values after 5 months of storage at 0°C in a regular atmosphere. The consistent occurrence of Phacidiopycnis spp. will require continuous monitoring and development of disease management strategies based on fungicide phenotypes and efficacy of existing fungicides assessed herein.

Prevalence of inappropriate antibiotic doses among pediatric patients of inpatient, outpatient, and emergency care units in Bangladesh: A cross-sectional study.

The heterogeneous pediatric populations, their physiological differences, along with the necessity of performing additional dose calculation, make the pediatric population more vulnerable to the incidences of inappropriate antibiotic doses. This study was conducted to examine and evaluate the appropriateness of antibiotic doses. A cross-sectional study with a quantitative approach was conducted in three hospitals located in Savar from January 06, 2021 to October 17, 2022. This study had used a convenient sampling method to collect 405 filled prescription orders from heterogeneous pediatric patients prescribed by physicians from emergency, inpatient, and outpatient care units of various clinical settings. The Harriet Lane Handbook was used as reference to investigate inappropriate doses of antibiotics. Subsequently, all analyses were conducted using the RStudio 1.3.959 software. Binary logistic regression was used to assess the risk of inappropriate antibiotic prescription in pediatrics. The overall prevalence of inappropriate antibiotic dosing in pediatrics was 335 out of 545 (61.5%). Overdosing (36.3%) and oral antibiotic prescriptions (64%) were more common than underdosing (20.4%) and parenteral antibiotics (36%). The majority (230 out of 405, 56.8%) of pediatric patients had prescriptions with inappropriate antibiotic doses, with prevalence rates of 33.8% for inpatients, 86.7% for outpatients, and 50% for emergency pediatrics. The results also indicated that pediatric patients in outdoor and emergency care units, infants, toddlers, and early childhood, those prescribed two antibiotics simultaneously, and those receiving parenteral antibiotics, were less likely to have inappropriate antibiotic dosages in their prescriptions. This study demonstrated that about one out of every two prescriptions had inappropriate antibiotic doses; in particular, prescriptions containing only one antibiotic exhibited a substantial proportion of inappropriate antibiotic doses. Inappropriate antibiotic doses may result in therapeutic failure, patient harm, and antibiotic resistance. Good clinical pharmacy practice and careful adherence to pediatric dosing standards may minimize inappropriate antibiotic doses.

Quality of life of stroke survivors in Bangladesh.

Objective: In Bangladesh, the factors that contribute to the reduced quality of life were not systematically investigated in long-term stroke survivors, and only a few studies have used preference-based measures to assess the quality of life. We sought to assess the quality of life in stroke survivors who comprise physical health status, psychological state, social relationship, and surrounding environment of the stroke patients. Methods: The quality of life among stroke patients was assessed with a semi-structured questionnaire using the validated Bangla Version of the World Health Organization, Quality-of-Life scale among the patients who survived beyond 28 days of first-ever stroke occurrence presenting in the Department of Physical Medicine and Rehabilitation, Bangabandhu Sheikh Mujib Medical University in the period between November 2020 and October 2021. Results: Of the 77 patients who were identified as post-stroke patients, the mean score of overall quality of life (as assessed by Q1 and scored in a range of 1-5) was 3.14 ± 1.08. The mean scores of quality of life were highest for the psychological domain (51.18 ± 19.73) followed by environmental (52.08 ± 13.13), social (45.62 ± 22.73), and physical domains (37.18 ± 18.56). According to the classification of the Bangla Version of the World Health Organization, Quality-of-Life, 75.3% had a low physical quality of life, 37.7% had a low psychological quality of life, 53.2% had a low social quality of life, and 53.2% had a moderate environmental quality of life. The average scores for the physical, psychological, social, and environmental domains were notably lower in stroke survivors with comorbid chronic conditions such as hypertension, diabetes, heart disease, asthma or chronic obstructive pulmonary disease, obesity, and ischemic heart disease in comparison to those without such conditions. Conclusion: In our study, post-stroke patients with lower quality of life were associated with factors such as female gender, lower level of education, urban dwellers, and chronic diseases.

Impacts of Ultrasonogram-Guided, Intra-fascial, Autologous, Activated Platelet-Rich Plasma Injection in Chronic Plantar Fasciitis: A Quasi-experimental Study.

Background Plantar fasciitis is the most common cause of foot pain. Patients with plantar fasciitis typically present with 'first step pain,' which tends to decrease with activity and worse with heavy use. This study determines the effect of ultrasound-guided, single-dose, platelet-rich plasma (PRP) injection in patients with chronic plantar fasciitis. Materials and methods It was a quasi-experimental trial carried out in the Department of Physical Medicine and Rehabilitation, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh, from March 2019 to March 2022. A total of 148 patients diagnosed with chronic plantar fasciitis were selected as samples. A total of 75 patients were allocated to group A (intra-lesional injection of autologous PRP with conservative management) and 73 patients to Group B (only conservative management). Both groups of patients were allocated to conservative management with exercises, shoe modification, activities of daily living (ADLs) instruction, and oral paracetamol. Results This study shows that in group A, the mean visual analog scale (VAS) score significantly reduced to 1.47±0.51 after six months of single-dose PRP injection (p<0.001). In group B, the VAS score also decreased substantially after conservative treatment. Though in groups A and B, pain reduction was significant, in group A, the pain was decreased more compared to group B and statistically significant differences were found between the two groups at the 12th week and 24th week. The foot function index (FFI) scores decreased significantly in group A after a single dose PRP injection, compared with group B treated with conventional therapy. In group A, FFI scores decreased from 49.09±5.72 to 7.67±3.41. The study revealed a significant difference between study groups in the 12th week and 24th week regarding FFI scores. Conclusion Ultrasound-guided intra-lesional autologous PRP Injection is safe and effective and recommended in patients with chronic plantar fasciitis, especially in recalcitrant cases after the failure of conservative treatment and corticosteroid injection.

Positive impacts of COVID-19 Lock down in Bangladesh: An online investigation.

Background: This research focuses on the positive impacts of the COVID-19 lockdown on society and the environment, despite acknowledging the widespread negative effects of the pandemic and lockdown measures. The research was aimed at pinpointing and evaluating the beneficial results stemming from these measures. Method: Data for the study was collected through an online survey distributed via Google forms to adults over the age of 18 across the country. A total of 1230 participants completed the survey, mostly from rural areas (61.7%), providing valuable insights for analysis. The questionnaire encompassed personal, family, and cohesive social data, along with information on the environment and biodiversity. The study utilized structural equation modeling (SEM) and confirmatory factor analysis (CFA) to analyze the data and examine correlations between variables. Results: The findings indicated that the COVID-19 lockdown had positive implications for individuals and society, leading to increased health consciousness, improved family relationships, and constructive social attitudes. Moreover, restrictions on access to natural tourist destinations and parks during the lockdown contributed to positive changes in biodiversity. These results highlight the importance of adopting appropriate measures during pandemics to foster personal and social well-being, as well as the preservation of natural environments and biodiversity. Conclusion: This study emphasizes the need for further research to promote sustainable living in similar situations. By understanding the data appropriately, individuals can play a constructive role in future pandemics, leading to positive outcomes for both society and the environment.

Molecular analysis of transgenic melon plants showing virus resistance conferred by direct repeat of movement gene of Cucumber green mottle mosaic virus.

Cucumber green mottle mosaic virus (CGMMV) is a major limiting factor in the production of melon plants worldwide. For effective control of this virus using the transgenic approach, the direct repeat of the movement protein gene of CGMMV was used for transforming melon plants by Agrobacterium tumefaciens. PCR and Southern blot analyses of T3 confirmed that they carried the transgene. Northern blot analysis with total RNA showed that transgene transcript RNA as well as siRNA was observed in all plants tested. Separate leaves or individual plants were inoculated with CGMMV and subjected to ELISA and RNA blot analysis using the coat protein gene probe of the virus. Compared to nontransgenic control, these plants were shown to have high virus resistance. Furthermore, cytosine of the transgene DNA in the plants was methylated. Thus, these results reveal that the transgenic lines were highly resistant to the virus through RNA silencing. Key message High virus resistance was obtained in transgenic melon plants with direct repeat of movement protein gene of Cucumber green mottle mosaic tobamovirus through RNA silencing.

Effects of heavy metals on fish physiology - A review.

The pollution by heavy metals poses a serious threat to the aquatic environment and to the organisms if the concentration of heavy metals in the environment exceeds the safe limits. Due to their non-biodegradable and long persistence nature in the environment, heavy metals cause toxicity in fish by producing oxygen reactive species through oxidizing radical production. In this review, we investigated the effects of heavy metals on fish physiology with special emphasis on hemato-biochemical properties, immunological parameters especially hormones and enzymes, histopathology of different major organs and underlying molecular mechanisms. All those parameters are significantly affected by heavy metal exposure and are found to be important bio-monitoring tools to assess heavy metal toxicity. Hematological and biochemical alterations have been documented including cellular and nuclear abnormalities in different fish species exposed to different concentrations of heavy metals. Major fish organs (gills, liver, kidneys) including intestine, muscles showed different types of pathology specific to organs in acute and chronic exposure to different heavy metals. This study also revealed the expression of different genes involved in oxidative stress and detoxification of heavy metals. In a nutshell, this article shades light on the manipulation of fish physiology by the heavy metals and sought attention in the prevention and maintenance of aquatic environments particularly from heavy metals contaminations.

Risk factors associated with self-medication among the indigenous communities of Chittagong Hill Tracts, Bangladesh.

BACKGROUND: In developing countries like Bangladesh, self-medication has become a predicament associated with health risks and clinical complications. To date, no studies have been conducted on the practice of self-medication among the indigenous population living in Chittagong Hill Tract (CHT). OBJECTIVES: This study was aimed to determine the prevalence of self-medication and analyzing the factors associated with it among the indigenous population in CHT. METHODS: This cross-sectional study was conducted from late October to early December 2020; among different indigenous group populations residing in the three districts of CHT aged 18 or more. A pre-tested and semi-structured questionnaire was developed to collect data on socio-demographic characteristics, health status, frequency of self-medication, reasons for self-medication in last one year, as well as other variables. Multivariate logistic regression was performed to assess associated factors with self-medication. RESULTS: A total of 1350 people from different indigenous populations were interviewed, among whom 49.9% practiced self-medication. The rate of self-prescribed antibiotics usage (80.9%) was significantly higher compared to other drugs. Self-prescribed medications were mostly used for diarrhea and food poisoning (60.6%), cough, cold and fever (51.4%), and headache (51.4%). A common source of self-prescribed medicines was community or retail pharmacy and the most reported reason for self-prescribed medication was the long-distance of healthcare facilities from home. CONCLUSION: The prevalence of self-medication is substantially high among indigenous people and the effect is alarming. Particular concern is the misuse of antibiotics and analgesic drugs. Increasing awareness among the population of the negative effect of self-medication and implementation of proper policies and actions are urgently needed to prevent self-medication among indigenous population in Bangladesh.

Alterations in hematological parameters and the structure of peripheral erythrocytes in Nile tilapia (Oreochromis niloticus) exposed to profenofos.

The burden of pesticide use from agricultural intensification lies in the fact that pesticides may end up in aquatic ecosystems and have pernicious effects on non-target organisms, including fish. Different blood biomarkers, including hemato-biochemical indices, erythrocytic nuclear abnormalities (ENA), and erythrocytic cellular abnormalities (ECA), were observed in Nile tilapia (Oreochromis niloticus) after exposure to varying sub-lethal concentrations (0%, 5%, 10%, 20%, and 40% of 96-h LC50) of profenofos at different time intervals (7, 14, 21, and 28 days). The results revealed that glucose and white blood cell (WBC) levels significantly increased, while hemoglobin, red blood cell (RBC), and packed cell volume (PCV) significantly decreased in a time- and concentration-dependent manner. Aberrant erythrocytic morphology-derived ENA, such as nuclear degeneration, micronuclear formation, binuclear development, nuclear budding, and karyopyknosis, significantly increased with time in profenofos-exposed groups compared to controls. Between the treatment and control groups, a significant execution was discerned for teardrop and fusion type ECA. For other cellular aberrations of erythrocytes, including elongated, twin, and spindle, a significant difference appeared only at the beginning of the experiment (day 7). This study concludes that the presence of widely used profenofos in aquatic systems has a pernicious effect on Nile tilapia.

Impacts of heavy metals on early development, growth and reproduction of fish - A review.

Heavy metals pollution causes a threat to the aquatic environment and to its inhabitants when their concentrations exceed safe limits. Heavy metals cause toxicity in fish due to their non-biodegradable properties and their long persistence in the environment. This review investigated the effects of heavy metals on early development, growth and reproduction of fish. Fish embryos/larvae and each developmental stage of embryo respond differently to the intoxication and vary from species to species, types of metals and their mode of actions, concentration of heavy metals and their exposure time. Many of the heavy metals are considered as essential nutrient elements that positively improve the growth and feed utilization of fishes but upon crossing the maximum tolerable limit these metals cause not only a hazard to fish health but also to human consumers and the disruption of ecological systems. Reduced gonadosomatic index (GSI), fecundity, hatching rate, fertilization success, abnormal shape of reproductive organs, and finally failure of reproduction in fish have been attributed to heavy metal toxicity. In summary, this review sheds light on the manipulation of fish physiology by heavy metals and seeks to raise sensitivity to the prevention and control of aquatic environmental contamination, particularly from heavy metals.

Financial and Mental Health Concerns of Impoverished Urban-Dwelling Bangladeshi People During COVID-19.

Background: The COVID-19 pandemic has impacted the physical, mental and financial health of many individuals. Individuals living in impoverished crowded settings may be particularly vulnerable to COVID-19-related stressors. How substantially marginalized groups like impoverished urban-dwelling individuals have been impacted during this pandemic is poorly understood. The present study aimed to investigate the associated factors of financial concerns and symptoms of depression and posttraumatic stress disorder (PTSD) during the COVID-19 pandemic among impoverished urban-dwelling individuals residing in Dhaka, Bangladesh. Methods: A cross-sectional survey was conducted between August and September 2020 using face-to-face interviews in six disadvantaged neighborhoods ("slums") in Dhaka. Individuals were interviewed using a semi-structured questionnaire consisting of questions assessing socio-demographics, lifestyle, financial well-being relating to the COVID-19 pandemic, depression, and PTSD. Results: Four-hundred-and-thirty-five individuals (male = 54.7%; mean age = 45.0 ± 12.0 years; age range = 18-85 years) participated. Most (96.3%) reported that their household income decreased due to the COVID-19 pandemic. Factors associated with decreased household incomes included female gender, primary education, joblessness, food scarcity and depression. Depression symptoms were linked to female gender, joblessness, divorce, living in a joint family, excessive sleep and smoking. Low incomes, excessive sleep, joblessness and food scarcity were positively associated with PTSD symptoms. In contrast, less sleep appeared protective against PTSD. Conclusions: Public health initiatives, in particular mental health services that target stress and biocentric approaches that consider how humans interact with multiple facets of nature, should be introduced to mitigate against potential financial and psychological effects of the pandemic on impoverished urban-dwelling individuals in Bangladesh.

Response to coronavirus disease 2019: Case study of one baking industry in Dhaka, Bangladesh.

The coronavirus disease 2019 (COVID-19) poses significant risks to health in the workplace for employees in the manufacturing sector of Bangladesh. A variety of preventive steps are being taken by many food industries to sustain their production during this period by ensuring food safety. In response to the current outbreak, early identification, preparedness for the growing threat, and employee well-being are of utmost importance. Food health is also a concern in this regard, as workers in the food industry remain close to food and packages. The risk of spreading the virus within the industry can be held to a minimum with timely action and concerted efforts. A study was carried out in one baking industry of Bangladesh to investigate their regular activities during the pandemic period. Until the writing of this report, there were no cases of COVID-19 among employees. Thus this case study shows how one baking industry in Bangladesh prepares and responds to the COVID 19 outbreak.

Evaluation of food safety knowledge, attitude, and self-reported practices of trained and newly recruited untrained workers of two baking industries in Dhaka, Bangladesh.

In Bangladesh, with the mounting esteem of bakery products, food safety issues in bakery industries are a paramount concern nowadays. In this regard, this current study was performed to evaluate food safety knowledge, attitude, and self-reported practices of two groups (160 trained and 55 new untrained) of workers from two popular baking industries in Dhaka, Bangladesh. A self-administrated questionnaire was used to acquire the data during the study. On food safety knowledge, attitude, and self-reported practices, trained workers' scores (33.01 ± 0.09, 14.86 ± 0.03, 10.66 ± 0.25, respectively) were significantly higher than the scores (9.82 ± 0.23, 10.44 ± 0.26, 5.91 ± 0.33, respectively) of newly appointed untrained workers. The quality assurance department displayed better knowledge, attitude, and self-reported practices scores than the rest of the departments of the industries. However, compared to knowledge and attitude, the self-reported practice was not up to a satisfactory level. According to the study, training can be proved effective for improving knowledge and attitude but does not always translate those into self-reported practice and behaviors. The results also reinforce the importance of conducting training for untrained workers and suggest further behavior-based food safety training for all employees.

Resistance Breeding Through RNA Silencing of Host Factors Involved in Virus Replication.

RNA silencing is a sequence-specific suppression of gene expression conserved in eukaryotes including fungi, plants, and animals. Based on this mechanism, crop improvements have been made to confer pathogen resistance and abiotic stress tolerance. Here we have applied this technique to produce virus resistant tomato plants using host genes involved in viral replication. Tomato homologs of Arabidopsis TOM1 involved in tobamovirus replication has been isolated and used to construct the plasmids that carried inverted repeats of the genes for induction of RNA silencing. Tomato plants were transformed by the plasmids via Agrobacterium, and tested for virus resistance. Actually, the T2 and T3 plants showed resistance to tomato mosaic virus. Here we describe the method to construct RNA silencing-inducing plasmids, to transform tomato plants and to check the introduction of transgenes and virus resistance.

Increase in water temperature increases acute toxicity of sumithion causing nuclear and cellular abnormalities in peripheral erythrocytes of zebrafish Danio rerio.

Global warming and indiscriminate usages of pesticides are notable concern to all. The present study has been conducted to evaluate the effects of high temperature on acute toxicity of sumithion in adult zebrafish. A 2-day renewal bioassay system was used to determine the 96 h LC50 value of sumithion at three temperature regimes, such as 25 °C, 30 °C, and 35 °C. Blood glucose (mg/dL) level was measured in control (0.0 mg/L) and low concentration (1.0 mg/L) of sumithion during the determination of LC50 in three temperature conditions. In addition, micronucleus (MN), erythrocytic nuclear abnormalities (ENA), and erythrocytic cellular abnormalities (ECA) tests were performed in the blood erythrocytes. The 96 h LC50 value of sumithion for zebrafish was significantly lower at 35 °C, which indicates that the toxicity of sumithion increases at higher temperature. Blood glucose level was significantly increased by sumithion in all temperature conditions, while it was significantly higher in the highest (35 °C) temperature compared to the lowest (25 °C) temperature in both control and sumithion-treated fish. Similarly, frequencies of MN, ENA, and ECA were elevated by sumithion in all temperature conditions, whereas it was significantly raised in the highest (35 °C) temperature compared to the lowest (25 °C) temperature in both control and sumithion treated fish. With increasing temperature in exposure to sumithion, dissolved oxygen decreased significantly, whereas free CO2 increased significantly. On the other hand, no distinct changes were observed in pH and total alkalinity during the experimental period. Therefore, it can be inferred that increasing temperature enhances the toxicity of sumithion in the zebrafish.

Selection Pressure Pathways and Mechanisms of Resistance to the Demethylation Inhibitor-Difenoconazole in Penicillium expansum.

Penicillium expansum causes blue mold, the most economically important postharvest disease of pome fruit worldwide. Beside sanitation practices, the disease is managed through fungicide applications at harvest. Difenoconazole (DIF) is a new demethylation inhibitor (DMI) fungicide registered recently to manage postharvest diseases of pome fruit. Herein, we evaluated the sensitivity of 130 P. expansum baseline isolates never exposed to DIF and determined the effective concentration (EC50) necessary to inhibit 50% germination, germ tube length, and mycelial growth. The respective mean EC50 values of 0.32, 0.26, and 0.18 µg/ml indicate a high sensitivity of P. expansum baseline isolates to DIF. We also found full and extended control efficacy in vivo after 6 months of storage at 1°C. We conducted a risk assessment for DIF-resistance development using ultraviolet excitation combined with or without DIF-selection pressure to generate and characterize lab mutants. Fifteen DIF-resistant mutants were selected and showed EC50 values of 0.92 to 1.4 µg/ml and 1.7 to 3.8 µg/ml without and with a DIF selection pressure, respectively. Resistance to DIF was stable in vitro over a 10-week period without selection pressure. Alignment of the full CYP51 gene sequences from the three wild-type and 15 mutant isolates revealed a tyrosine to phenylalanine mutation at codon 126 (Y126F) in all of the 15 mutants but not in the wild-type parental isolates. Resistance factors increased 5 to 15-fold in the mutants compared to the wild-type-isolates. DIF-resistant mutants also displayed enhanced CYP51 expression by 2 to 14-fold and was positively correlated with the EC50 values (R 2 = 0.8264). Cross resistance between DIF and fludioxonil, the mixing-partner in the commercial product, was not observed. Our findings suggest P. expansum resistance to DIF is likely to emerge in commercial packinghouse when used frequently. Future studies will determine whether resistance to DIF is qualitative or quantitative which will be determinant in the speed at which resistance will develop and spread in commercial packinghouses and to develop appropriate strategies to extend the lifespan of this new fungicide.