Vermi-remediation impacts on growth and metals bioaccumulation in tomato irrigated with wastewater.

Due to their persistence in the environment, and their highly toxic and bioaccumulative nature, heavy metals are well known to the environment. Vermicompost has gained popularity because it improves soil properties and, most importantly, remediates and immobilizes heavy metals. The present study assessed vermicompost effects on heavy metal bioaccumulation in tomato plants irrigated with wastewater. A plastic bag experiment was carried out with 5 kg of growing media in each bag. Growing media contain garden soil with four levels of vermicompost mixed at 0%, 5%, 15%, and 25%. The pots were irrigated with wastewater from different industries and tap water, which was taken as control. Wastewater was collected from the pharmaceutical industry, plastic industry, and sewage water of Hayatabad Industrial Estate, Peshawar. Vermicompost application significantly affected all tomatoes' growth attributes and heavy metals concentration. Results revealed that minimum Cd (2.48 mg kg-1), Cr (1.27 mg kg-1), Cu (4.10 mg kg-1), and Pb (0.62 mg kg-1) concentrations were recorded in tomatoes cultivated in 25 % vermicompost amended soil, while, maximum Cd (5.23 mg kg-1), Cr (2.29 mg kg-1), Cu (8.84 mg kg-1) and Pb (2.18 mg kg-1) concentrations were reported in sewage water irrigated plants., Overall, vermicompost applied at 25% significantly enhanced plant growth and yield, reducing the bioavailability and bioaccumulation of heavy metals. From the finding of this study, it is observed that wastewater irrigation of plants should be avoided because of the high level of heavy metals; in contrast, the application of vermicompost is highly recommended as compost reduces heavy metals bioaccumulation and enhances productivity.

Spontaneous coronary artery dissection (SCAD) and takotsubo cardiomyopathy (TCM) - A potential association.

Background: Spontaneous coronary artery dissection and takotsubo cardiomyopathy are increasingly recognized in the last two decades. Case reports have shown both entities can present concomitantly - however, little is known about their association. Methods: In this retrospective study we aimed to explore a potential association between SCAD and TCM using the Nationwide Inpatient Sample. The odds of having TCM among patients with SCAD compared with those who did not have SCAD were calculated as an odds ratio. Conversely, the odds of having SCAD among patients with TCM compared with those who did not have TCM were also calculated. The primary outcome was the odds of TCM among patients with a primary diagnosis of SCAD and vice versa. The secondary endpoint was the odds of in-hospital mortality among patients with SCAD, and/or TCM. Results: Hospitalized patients who had SCAD were 7.12 (95 % CI: 6.28-8.08) times more likely to also have TCM than those who did not have SCAD (p < 0.0001).), while patients with TCM were 6.91 (95 % CI: 6.07-7.85) times more likely to have SCAD compared to those who didn't have TCM adjusted for age, gender, race, hypertension, hyperlipidemia, and diabetes mellitus (p < 0.0001). Conclusion: This data indicate that patients with either SCAD or TCM are seven times more likely to be diagnosed concomitantly with both, compared to the patients without either diagnosis [after adjusting for age, gender, race, hypertension, hyperlipidemia, and diabetes mellitus]. Our data are consistent with the growing body of evidence supporting an association between SCAD and TCM and raise the question of a common pathophysiologic mechanism.

Nickel(II) Complexes of Tripodal Ligands as Catalysts for Fixation of Atmospheric CO2 as Organic Carbonates.

The fixation of atmospheric CO2 into value-added products is a promising methodology. A series of novel nickel(II) complexes of the type [Ni(L)(CH3 CN)2 ](BPh4 )2 1-5, where L=N,N-bis(2-pyridylmethyl)-N', N'-dimethylpropane-1,3-diamine (L1), N,N-dimethyl-N'-(2-(pyridin-2-yl)ethyl)-N'-(pyridin-2-ylmethyl) propane-1,3-diamine (L2), N,N-bis((4-methoxy-3,5-dimethylpyridin-2-ylmethyl)-N',N'-dimethylpropane-1,3-diamine (L3), N-(2-(dimethylamino) benzyl)-N',N'-dimethyl-N-(pyridin-2-ylmethyl) propane-1,3-diamine (L4) and N,N-bis(2-(dimethylamino)benzyl)-N', N'-dimethylpropane-1,3-diamine (L5) have been synthesized and characterized as the catalysts for the conversion of atmospheric CO2 into organic cyclic carbonates. The single-crystal X-ray structure of 2 was determined and exhibited distorted octahedral coordination geometry with cis-α configuration. The complexes have been used as a catalyst for converting CO2 and epoxides into five-membered cyclic carbonates under 1 atmospheric (atm) pressure at room temperature in the presence of Bu4 NBr. The catalyst containing electron-releasing -Me and -OMe groups afforded the maximum yield of cyclic carbonates, 34% (TON, 680) under 1 atm air. It was drastically enhanced to 89% (TON, 1780) under pure CO2 gas at 1 atm. It is the highest catalytic efficiency known for CO2 fixation using nickel-based catalysts at room temperature and 1 atm pressure. The electronic and steric factors of the ligands strongly influence the catalytic efficiency. Furthermore, all the catalysts can convert a wide range of epoxides (ten examples) into corresponding cyclic carbonate with excellent selectivity (>99%) under this mild condition.

Synergy of 1-MCP and hypobaric treatments prevent fermented flavour and improve consumers' acceptability of 'Shughri' pear.

Development of fermented flavour during storage reduces acceptability of Shughri pear. Therefore, the current study was designed to investigate the combined effect of 1-Methylcyclopropene (1-MCP) and hypobaric treatment on stability of Shughri pear during 120 days of storage. Fruit were treated individually or combinedly with 25, 50, and 75 kilo pascal hypobaric treatments for 4 h and 1-MCP (0.3 µLL-1 and 0.6 µLL-1) for 24 h, whereas control received no treatment. The pears were stored for 120 days at (0 ± 1 °C, 85 ± 5% RH), and were evaluated after every 30 days. After cold storage, pears were shifted to simulated retail conditions (20 ± 3 °C, 65 ± 5% RH). The combination of 25 kPa + 0.6 µLL-1 1-MCP significantly (P ≤ 0.05) delayed fruit ripening, reduced Alcohol dehydrogenase (ADH), and Pyruvate decarboxylase (PDC) activities, maintained the quality, and led to higher consumers' acceptability of the pear followed by 50 kPa + 0.6 µLL-1 and 25 kPa + 0.3 µLL-1. The control fruit were marketable for a week after storage with relatively less acceptability due to fermented flavour compared to treated fruit, marketable for more than two weeks. Among all the treatments, the synergy of 1-MCP and hypobaric treatment 25 kPa + 0.6 µLL-1 1-MCP improved the postharvest storage life and quality parameters, preventing development of fermented flavour in the pears. The experiment was conducted on pilot scale, for commercial application, the results of this study should be validated on large scale.

Alkanna tinctoria-based sustainable alkanin natural colorant for eco-dyeing of wool.

The awareness of sustainability and widespread utilization of green technologies in textile dye houses are revolutionizing not only textile industries but related fields. The current study is concerned with ultrasonic (US)-assisted utilization of extracts of Alkanna tinctoria (a source of natural alkanin dye) for wool dyeing. The extracts are obtained in various media, and both extracts and wool fabrics have been  US treated for 15-60 min. Dyeing is performed by applying variable parameters and utilizing herbal-based extracts as a source of bio-mordant, hence improving the fastness rating and enhancing color strength. Good color strength and fastness ratings are obtained using irradiated extract at 4 pH when the US-treated wool fabric is dyed at 65 °C for 60 min before and after chemical and bio-mordanting. For comparative studies, chemical mordants are also employed. In contrast to chemical mordants, the bio-mordants have made the dyeing process more sustainable with good to excellent fastness rating.

Designing a Propellane-based Nonlinear Optically Active System Absorbing in Three Different Wavelength Regions.

The aim of this work is to demonstrate the possibility of using propellane in designing a molecule that can absorb in three different wavelength regions and their nonlinear optical (NLO) activity can be fine-tuned by varying the three wings. We considered 22 tailor-made propellane derivatives consisting of phenyl, naphthyl, and biphenyl wings for this purpose. Using the state-of-the-art linear and quadratic response methods within TD-DFT and RI-CC2 theories and a suitable generalized few-state model that quantifies the effect of orientation of different transition moments on NLO properties, we discussed how and why the linear and nonlinear optical activity of propellane vary when the three wings are assembled successively to construct a full-propellane.

The Impact of Authentic Leadership on Innovative Work Behavior: Mediating Roles of Proactive Personality and Employee Engagement.

The purpose of the study is to investigate the impact of authentic leadership and proactive personality on innovative work behavior through dual mediation approach. This study applied a judgment sampling technique and data were gathered from 311 high-tech manufacturing industries of Shenzhen, China. The measurement model and structural model were tested using structural equation modeling technique through AMOS 24 software. The results indicate that authentic leadership has a positive and significant effect on proactive personality. Meanwhile, findings show that proactive personality has a significant impact on innovative work behavior. Moreover, findings show that proactive personality positively mediates the relationship between authentic leadership and innovative work behavior. Furthermore, findings illustrate that work engagement positively mediates the relationship between proactive personality and innovative work behavior. This study provides insightful and valuable implications to high-tech manufacturing industries executives and regulators interested in organizational productivity.

The Impact of Transformational Leadership on Affective Organizational Commitment and Job Performance: The Mediating Role of Employee Engagement.

This study investigated the impact of transformational leadership on affective organizational commitment and job performance with the mediating role of employee engagement. This study gathered data from 845 hotel employees in China and the structural equation modeling technique was used to verify the results. The findings indicated that transformational leadership has a positive effect on affective organizational commitment and job performance. Meanwhile, results showed that employee engagement partially mediates in the relationship between transformational leadership, affective organizational commitment, and job performance. This study contributes to the research on transformational leadership in the Chinese hospitality sector and analyzes its effects on work performance metrics. Furthermore, theoretical and practical implications were also discussed in this article.

Callus Induction, Proliferation, Enhanced Secondary Metabolites Production and Antioxidants Activity of Salvia moorcroftiana L. as Influenced by Combinations of Auxin, Cytokinin and Melatonin

Abstract: Tissue culture technique is one of the best methods to reproduce salvia plant Therefore, the aim of this research was to enhance the in-vitro callus proliferation and production of secondary metabolites of S. moorcroftiana using different combinations of auxin, cytokinin and melatonin. Initially, callus induction was optimized using indole acetic acid (IAA), 2, 4-dichlorophenoxy acetic acid (2,4-D), and naphthalene acetic acid (NAA) applied at different concentrations in combination with 1 mg L-1 of 6-benzylaminopurine (BAP). The results indicates that earliest days to callus induction (14.67 days) was occurred in the media fortified with 2, 4-D+BAP (2.0+1.0 mgL-1). Whereas the highest callus initiation (100%) was induced on MS medium incorporated with 2,4-D+BAP (1+1mgL-1). Furthermore, maximum fresh weight was obtained when 2,4- D + BAP at the rate of (1+ 1mg L-1) was incorporated and dry weight was attained when 2,4- D + BAP at the rate of (2+1 mg L-1) was added to MS media. The maximum fresh and dry weight was obtained when melatonin at rate of 1.5 mg L-1 was supplemented with MS media including 2,4-D + BAP (1+1mg L-1), moreover the maximum DPPH scavenging activity, total phenolic and flavonoid content was noted when supplemented with melatonin at rate of 1.5 mg L-1. In conclusion, among various concentrations of plant growth regulators, 2,4- D + BAP at the rate of (1+ 1mg L-1) along with 1.5 g L-1 melatonin was the best for callus growth and production of secondary metabolites of S. moorcroftiana.

Biochar supplementation regulates growth and heavy metal accumulation in tomato grown in contaminated soils.

Biochar application has recently gained increased attention to reclaim heavy metal degraded soils. In this context, the present study investigated the effects of biochar on the growth regulation and heavy metal accumulation in tomato grown on contaminated soils. A two-factorial design with factor A including three treatments with mine (contaminated soil) and garden soil in the following ratio viz., T1 = 1:2, T2 = 1:1, and T3 = 2:1, and garden soil only as control; whereas factor B consists of biochar amendments at three levels viz., B1 (3%), B2 (6%), and B3 (9%). Our results revealed significant negative effects of heavy metal-contaminated soil on plant growth, and besides resulted heavy metal accumulation in tomato fruit. Tomato plants showed maximum reduction of growth in T3 followed by T2, and lowest in T1, a similar pattern was found for accumulation of heavy metals in the fruit. However, the application of biochar reduced the bioavailability and accumulation of heavy metals in the tomato fruit, as well as improved plant growth in contaminated soils. Overall, among the three biochar treatments, B2 was determined as the optimum level for improved growth coupled with reduced heavy metal accumulation in the tomato fruit. Besides, biochar application decreased the daily intake of metals and human health risk index values, thus alleviating the health risk. Hence, the present study demonstrated a positive role of biochar in reclaiming heavy metal-contaminated soils and in increasing the plant growth.

Fitness cost, realized heritability and stability of resistance to spiromesifen in house fly, Musca domestica L. (Diptera: Muscidae).

The house fly, Musca domestica L. (Diptera: Muscidae), is an insect pest of public health and veterinary importance. Spiromesifen is a new chemistry insecticide widely used for the management of sucking insect pests of vegetables and crops. In the present study, assessment of resistance risk and fitness costs associated with spiromesifen resistance in M. domestica was studied. Moreover, stability of resistance to spiromesifen and other tested insecticides (fipronil, spinosad, and bifenthrin) was evaluated in the spiromesifen-selected-strain (SPIRO-SEL-POP). After 7-generations of selection with spiromesifen, SPIRO-SEL-POP developed 108.76-fold resistance compared with the unselected strain (UNSEL-POP). The estimated value of realized heritability was 0.59 for spiromesifen resistance. Due to withdrawal of spiromesifen selection for five generations (F6-F10) on SPIRO-SEL-POP, a decline in LC50 values against spiromesifen, spinosad and bifenthrin was 0.16, 0.14 and 0.13-folds, respectively. In biological trait experiments, larval weight of Cross1 (SPIRO-SEL-POP♀ × UNSEL-POP♂) and SPIRO-SEL-POP was significantly lower than that of Cross2 (SPIRO-SEL-POP♂ × UNSEL-POP♀) and UNSEL-POP. Pupal weight of SPIRO-SEL-POP was higher when compared with Cross1 while it was similar to that of Cross2 and UNSEL-POP. Adult emergence rate of UNSEL-POP was higher than Cross1, but similar to the Cross2 and SPIRO-SEL-POP. The SPIRO-SEL-POP and Cross1 showed the lowest relative fitness when compared with USEL-POP and Cross2. Intrinsic rate of natural increase of SPIRO-SEL-POP was much lower than that of UNSEL-POP and Cross2 followed by Cross1. The SPIRO-SEL-POP exhibited lower biotic potential when compared with UNSEL-POP and Cross2 but similar to Cross1. Fecundity and hatching rates were lower in SPIRO-SEL-POP compared to UNSEL-POP. It could be concluded that spiromesifen resistance in M. domestica comes with a cost and is instable. Therefore, spiromesifen rotation with other insecticides and withdraw of its usage for some period could help to sustain its efficacy by delaying the development of resistance.

Remediation of industrial wastewater using four hydrophyte species: A comparison of individual (pot experiments) and mix plants (constructed wetland).

Remediation and management of industrial wastewater (IWW) using hydrophytes act as one of the cost effective and environmentally friendly technologies. The present study was conducted to assess the role and efficiency of selected four hydrophyte species through constructed wetland (CW) for the removal of heavy metals (HMs) from IWW. Samples of wastewater (WW) were collected from the main drain of Hayatabad Industrial Estate (Peshawar, Pakistan) and analysed for HMs like cadmium (Cd), copper (Cu) and lead (Pb) along with basic physicochemical parameters like pH, electric conductivity (EC), total suspended solids (TSS), total dissolved solids (TDS), dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), dissolved organic carbon (DOC) through standard analytical methods. Four hydrophytes species such as Typha latifolia (cattail), Eichhornia crassipes (water hyacinth), Lemna gibba (duck weed) and Pistia stratiotes (water cabbage) were transplanted into CW (mix cultivation). Each selected species was also cultivated in individual pots for investigating their efficiency to remove HMs. The Cd, Cu and Pb removal efficiency of CW was recorded as 39.5%, 80.3% and 85.5%, respectively. The removal efficacy of hydrophyte species including cattail, water hyacinth, duck weed and water cabbage was 96.2%, 72.2%, 60.4% and 93.3%, respectively for Cd, while 83.6%, 82.3%, 90.0% and 81.7% for Cu and 95.9%, 78.0%, 91.3% and 97.1% for Pb, respectively. Findings of T-Test and One-Way ANOVA showed that the concentrations of Cd, Cu and Pb in IWW were significantly (P ≤ 0.01) reduced by the treatment of hydrophytes revealing the higher efficiency of CW and selected species used in this study. The HMs were removed in order of Pb > Cu > Cd. Most efficient removal for Cd was found by water cabbage, Cu by duck weed and Pb by water hyacinth. It was concluded that CW is one of the environmentally friendly and cost-effective technologies that can be used for the treatment of IWW due to the efficiency of hydrophytes species in terms of HMs removal.

Impedance Model of Cylindrical Nanowires for Metamaterial Applications.

In metamaterials, metallic nanowires are used for creating artificial materials to functionalize them for various nanophotonics applications. Strong polarization-dependent response coupled with complex dielectric function at optical frequencies gives additional degrees of freedom to achieve scattering, absorption, and other benefits that go much beyond what is possible with conventional materials. In this paper, we propose an extended cylindrical wave impedance approach at optical frequencies to model the internal and external impedance of the metallic nanowire. Equivalent analytical expression for the scattering, extinction, and absorption cross-sectional area efficiencies are derived in terms of impedances. The motivation is to develop an all-mode solution ( TM n and TE n modes), by bringing the complex problem of plasmonic nanowire to linear system theory, where established methods can be applied to enable new applications. The equivalence of the impedance solution is compared with electromagnetic field solution and numerical full-wave field simulations. The proposed solution is accurate and may contribute to the rapid and efficient future designs for the metallic nanowire-based nanophotonic metamaterials.

Concentrations, dietary exposure, and human health risk assessment of heavy metals in market vegetables of Peshawar, Pakistan.

The present study was carried out to assess heavy metal concentrations in ready-to-eat vegetables (RTEs) collected from open markets. Samples of RTEs including lettuce, coriander, and carrot were collected from five different local markets of Peshawar, Pakistan including Industrial estate, Board, Agriculture University, Firdos, and Hashtnaghri on four different dates, i.e., 21st March, 04th April, 19th April, and 05th May, 2016. The samples were analyzed through atomic absorption spectrophotometer to see the amount of heavy metals present in them. The elements studied were cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb). Maximum Cd, Cr, Cu, Ni, and Pb concentrations in samples collected from different markets were 0.68, 5.28, 12.31, 7.61, and 25.04 mg kg-1, respectively, whereas maximum Cd, Cr, Cu, Ni, and Pb concentrations in RTEs collected at different dates were 0.59, 4.08, 14.85, 7.23, and 21.97 mg kg-1, respectively. The mean Cd, Cr, and Pb concentrations exceeded the permissible limits, while Cu and Ni were found within the limits set by FAO/WHO in all studied RTEs. The daily dietary intake and hazard quotient (HQ) showed great variations. The HQ was found > 1 for Pb in all studied vegetables, while it was < 1 for Cd, Cr, Cu, and Ni with few exceptions. It can be concluded from the study that heavy metal concentrations were above the permissible toxicity levels and their continuous consumption may cause several health issues.

Potential Application of Venom Proteins in Designing of Medicines for Treating Human Neurodegenerative Disorders.

BACKGROUND: Neurodegenerative disorder are persistently increasing and relentlessly affecting the individuals, families and society as whole. Regrettably these disorders are resistant to the available drugs, the outcomes are only palliative while the side effects of the therapy harm the patient compliance as well as treatment. Drugs from venomous source have been considered as an effective alternative for such types of disorders, particularly neurodegenerative diseases. Due to emerging advancement in the field of proteomics, genomics and molecular biology, characterization and screening of these novel compounds become more assessable. CONCLUSION: In this reverence, the present study reviews the current consideration of the mode of action and the future prediction concerning the use of novel compounds isolated from arthropods and other venomous animals in the treatment of major neurodegenerative diseases such as Parkinson disease, Alzheimer disease, Multiple Sclerosis, Epilepsy and Amyotrophic Lateral Sclerosis.

The effects of biochar and rice husk on adsorption and desorption of cadmium on to soils with different water conditions (upland and saturated).

Hard wood derived biochar (BCH) and rice husk (RCH) were applied to soils having upland and saturated conditions to investigate their effects on adsorption and desorption of Cd by conducting incubation and batch experiments. The results obtained from the experiments indicated that BCH increased Cd sorption by 59-71% onto saturated soil (SS), while by 57-84% onto upland soil (US). The application of RCH also increased the sorption of Cd onto the soils under both water conditions but the increases were less as compared to BCH. With RCH application, 21-41% increases in sorption of Cd on SS and 38-54% on US soils were observed. The Langmuir equation fitted sorption of Cd better than Freundlich with R2 > 0.95 for all selected treatments. Both electrostatic and non-electrostatic mechanisms played their important roles in the adsorption of Cd in the amended soils. BCH enhanced non-electrostatic adsorption as compared to RCH and thus control and induced greater specific adsorption capacity. High desorption percentage of pre-adsorbed Cd on soils were observed both with and without amendments. Decreases in desorption percentage of pre-adsorbed Cd on both soils were observed with BCH with a highest decrease on SS (39%). The application of selected amendments into different soils increased Cd adsorption of soils through both electrostatic and non-electrostatic mechanisms and the contribution of both the mechanisms varied with types of amendments and soil conditions. BCH material showed promising results in Cd adsorption as compared to RCH for different selected soils and conditions but cost-benefit analysis is needed in field condition.

Evaluation of antibiotic resistant bacteria in underground drinking water and transfer of their resistant character to normal flora of the body.

The untreated surface water for drinking and domestic use is an alarming situation to public health especially in prevalence of antibiotics resistant bacteria. This investigation aimed to isolate and identify the antibiotic resistance bacteria in underground water samples in district Dera Ismail Khan, Pakistan. The underground water samples were collected from four different places using hand pumps (Khyber town, riverside, Gomal University and united town). Cultured on nutrient agar media, identified by Gam staining and biochemical tests. There after antibiotic resistance assay were performed by measuring zone of inhibition of different antibiotics by disc diffusion method. Six different bacterial colonies were isolated and identified as Enterobacteriaceae, Serriata specie, Proteues, Pseudomonas, all these bacterial colonies were 33% resistant to chloramphenicol with and 100% resistant to amoxicillin. Some colonies were also considered as resistant, according to the criteria of National Committee for Clinical Records (NCCL) that less than 10mm zone of inhibition are considered as resistant. Subsequently, the chloramphenicol resistance bacteria were analyzed for their ability to transfer resistant gene to sensitive bacteria. In in-vitro method, an isolate M1b (resistant) was found capable to transfer resistance gene to M1a isolate (sensitive) in nutrient rich environment. It was concluded that antibiotics resistance bacteria found in underground water, moreover capable of transferring the antibiotic resistant character to suitable recipient i.e. normal flora of the body or to other pathogens by conjugation.

Soil contamination with cadmium, consequences and remediation using organic amendments.

Cadmium (Cd) contamination of soil and food crops is a ubiquitous environmental problem that has resulted from uncontrolled industrialization, unsustainable urbanization and intensive agricultural practices. Being a toxic element, Cd poses high threats to soil quality, food safety, and human health. Land is the ultimate source of waste disposal and utilization therefore, Cd released from different sources (natural and anthropogenic), eventually reaches soil, and then subsequently bio-accumulates in food crops. The stabilization of Cd in contaminated soil using organic amendments is an environmentally friendly and cost effective technique used for remediation of moderate to high contaminated soil. Globally, substantial amounts of organic waste are generated every day that can be used as a source of nutrients, and also as conditioners to improve soil quality. This review paper focuses on the sources, generation, and use of different organic amendments to remediate Cd contaminated soil, discusses their effects on soil physical and chemical properties, Cd bioavailability, plant uptake, and human health risk. Moreover, it also provides an update of the most relevant findings about the application of organic amendments to remediate Cd contaminated soil and associated mechanisms. Finally, future research needs and directions for the remediation of Cd contaminated soil using organic amendments are discussed.

Selection, Realized Heritability, and Fitness Cost Associated With Dimethoate Resistance in a Field Population of Culex quinquefasciatus (Diptera: Culicidae).

Mosquitoes are known to be vectors of numerous diseases leading to human morbidity and mortality at large scale in the world. Insecticide resistance has become a serious concern in controlling the insect vectors of public health importance. Dimethoate is an organophosphate insecticide used to control different insect pests including mosquitoes. Biological parameters of susceptible, unselected, and dimethoate-selected strains of Culex quinquefasciatus Say were studied in the laboratory to recognize resistance development potential and associated fitness cost. The dimethoate-selected strain showed 66.48-fold resistance to dimethoate compared with the susceptible strain after three continuous selections of generations. Realized heritability estimates of dimethoate resistance in Cx. quinquefasciatus yielded a value of 0.19. In dimethoate-selected strain, the biological traits including larval weight, survival from first instar to pupae, fecundity, number of next-generation larvae, relative fitness, net reproductive rate, intrinsic rate of natural increase, and biotic potential were significantly reduced as compared with the unselected strain. However, adult longevity, mean relative growth rate, weight of egg raft, female ratio, pupal duration, and emergence rate of the dimethoate-selected strain did not differ significantly compared with that of the unselected strain. This study provides useful information to devise retrospective management strategy for dimethoate resistance in Cx. quinquefasciatus.

Larval Habitat Substrates Could Affect the Biology and Vectorial Capacity of Culex quinquefasciatus (Diptera: Culicidae).

Culex quinquefasciatus Say is an important disease vector throughout much of the world. Experiments were conducted to determine the effects of different larval habitat substrates on the fitness and biting efficiency of Cx. quinquefasciatus adults. Our findings indicate that the development time (egg to adult) of larvae reared in irrigation water was 8.63 d while that of larvae reared in distilled water was 17.10 d (Effect size = 0.95). However, the rate of adult emergence was similar for all the tested treatments. Furthermore, the mean weight of an egg raft varied between larval habitats: distilled water (1.83 mg), rainfall water (1.25 mg), irrigation water (1.52 mg), and sewerage water (2.52 mg) (Effect size = 0.91). But, the fecundity (eggs per female) and hatchability (%) were statistically similar in all the rearing mediums (Effect size = 0.79). Longevity of females in all the tested populations did not differ significantly (Effect size = 0.91). The mean relative growth rates of larvae reared in tap water (0.80) and distilled water (0.86) habitats were lower than growth rates in all other rearing habitats (Effect size = 0.96). The intrinsic rate of natural increase in tap water (0.27) and irrigation water (0.35) was significantly higher than that in distilled water (0.09) and sewerage water (0.16) (Effect size = 0.84). Adults reared in rain water had the highest biting efficiency among all the tested populations. These results provide useful information for the management of Cx. quinquefasciatus.