Emamectin benzoate, a semisynthetic bioinsecticide, has been used frequently for the management of lepidopteran pests of cotton worldwide. To assess the resistance risk and design strategy for resistance management, life history traits... more
Emamectin benzoate, a semisynthetic bioinsecticide, has been used frequently for the management of lepidopteran pests of cotton worldwide. To assess the resistance risk and design strategy for resistance management, life history traits were established for emamectin benzoate-resistant, unselected and susceptible S. litura strains based on the laboratory observations. Bioassay results showed that the emamectin benzoate-selected strain developed a resistance ratio of 911-fold compared with that of the susceptible strain. The emamectin-selected strain had a relative fitness of 0.37 and lower prepupal and pupal weights, prolonged larval duration and development time, lower fecundity and hatchability compared with the susceptible strain. Mean population growth rates, such as intrinsic rate of population increase and biotic potential, were lower for the emamectin-selected strain compared with the susceptible strain. Development of resistance can cost considerable fitness for the emamectin-selected strain. The present study provided useful information for determining potential management strategies to overcome development of resistance.
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In this study, methyl 2-(quinolin-8-yloxy) acetate (2) obtained by reaction of 8-hydroxyquinoline (1) with methyl chloroacetate was condensed with hydrazine hydrate to afford the carbohydrazide (3). Thio/semicarbazide derivatives (4a, 4b,... more
In this study, methyl 2-(quinolin-8-yloxy) acetate (2) obtained by reaction of 8-hydroxyquinoline (1) with methyl chloroacetate was condensed with hydrazine hydrate to afford the carbohydrazide (3). Thio/semicarbazide derivatives (4a, 4b, 4c, 4d, 4e, 4f, 4g) were obtained by treatment of the 3 with substituted phenyl iso/thioisocyanates. The 4a, 4b, 4c, 4d, 4e, 4f, 4g on acidic and basic intramolecular cyclization led to N-(aryl)-5-((quinolin-8-yloxy)methyl)-1,3,4-oxa/thiadiazol-2-amines (5a, 5b, 5c, 5d, 5e, 5f, 5g) and 4-aryl-5-((quinolin-8-yloxy)methyl)-2H-1,2,4-triazole-3(4H)-thiones (6a, 6b, 6c, 6d, 6e, 6f, 6g), respectively. All the synthesized compounds were characterized by spectroscopic techniques and elemental analyses. The thiosemicarbazide (4c) was also confirmed by X-ray crystallography.
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Research Interests: Chemistry, Organic Chemistry, Photochemistry, Fluorescence, Palladium, and 3 moreTetrahedron, Tetra, and Aryl
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Oxycarenus hyalinipennis Costa is a polyphagous insect pest and can develop insecticide resistance. The resistance of O. hyalinipennis to neonicotinoids (clothianidin and dinotefuran), flonicamid, and conventional insecticides; carbamates... more
Oxycarenus hyalinipennis Costa is a polyphagous insect pest and can develop insecticide resistance. The resistance of O. hyalinipennis to neonicotinoids (clothianidin and dinotefuran), flonicamid, and conventional insecticides; carbamates (methomyl and carbosulfon), organophosphates (chlorpyrifos and malathion), and pyrethroids (cypermethrin and zeta-cypermethrin) was evaluated. The O. hyalinipennis populations were sampled from four locations in Pakistan and performed bioassays against the insecticides by leaf dip protocol. The O. hyalinipennis’ populations showed low resistance to carbosulfan (resistance ratio (RR) = 2.06–6.34) and methomyl (RR = 2.78–7.27), moderate to high resistance to chlorpyrifos (RR = 30–45), malathion (RR = 20.29–88.19), and flonicamid (RR = 14.24–46.97), in comparison with the susceptible strain. Susceptibility to low resistance against cypermethrin (RR = 1.27–2.82), zeta-cypermethrin (RR = 2.62–3.38), and clothianidin (RR = 1.74–3.40), and low to moderate resistance to dinotefuran (RR = 3.84–13.43) in the field populations, was observed compared to the susceptible strain. A rotational usage of carbamates and pyrethroids with an integrated pest management tool should be considered to deal with O. hyalinipennis’ insecticide resistance.
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House fly, Musca domestica L., (Diptera: Muscidae) is an insect pest of public health and veterinary importance with ability to develop resistance to insecticides. Methoxyfenozide, an ecdysone agonist, is a bio-rational insecticide being... more
House fly, Musca domestica L., (Diptera: Muscidae) is an insect pest of public health and veterinary importance with ability to develop resistance to insecticides. Methoxyfenozide, an ecdysone agonist, is a bio-rational insecticide being used for the management of various insect pests, including house flies. To design an effective resistance management strategy, life history traits based on laboratory observations were established for methoxyfenozide resistant (MXY-SEL), unselected counterpart (UNSEL) and reciprocal cross strains of house fly. The MXY-SEL developed a resistance ratio of 160.99 after 30 generations of selection with methoxyfenozide compared to the UNSEL. The MXY-SEL showed very low cross-resistance to cyromazine, fipronil and chlorpyrifos and no cross-resistance to spinosad and bifenthrin, when compared to the Methoxy-Field population. Resistance to methoxyfenozide, cyromazine, fipronil, spinosad, chlorpyrifos, and bifenthrin was unstable in the MXY-SEL. The MXY-SEL had a reduced relative fitness (0.31), with lower hatchability, lower number of next generation larvae, lower intrinsic rate of natural increase, and lower biotic potential compared to the UNSEL. Disadvantageous life history traits of the MXY-SEL suggest that development of resistance to methoxyfenozide has considerable costs of fitness for this strain. Moreover, the unstable resistance to tested chemicals provides useful information to preserve the efficacy of these chemicals.
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Abstract Spotted bollworm, Earias vittella Fabricius (Lepidoptera: Noctuidae), is a serious pest of cotton and okra in South Asia, including Pakistan. E. vittella has developed resistance to most classes of insecticides, particularly... more
Abstract Spotted bollworm, Earias vittella Fabricius (Lepidoptera: Noctuidae), is a serious pest of cotton and okra in South Asia, including Pakistan. E. vittella has developed resistance to most classes of insecticides, particularly pyrethroids. The aim of this study was to monitor the resistance status of four different field populations of E. vittella collected from Punjab, Pakistan in 2009–2010 to pyrethroid, organophosphate and biorational insecticides. Due to time constraints, we were unable to produce our own susceptible population, therefore we used the data from a published susceptible population of our institute. For the five pyrethroids evaluated, the range of resistance ratios were 211–432 fold for lambda-cyhalothrin, 146–417 fold for bifenthrin, 42–123 fold for cypermethrin, 17–31 fold for deltamethrin and 30–61 fold for esfenvalerate when compared to published results for the susceptible population. For the two organophosphate insecticides evaluated, the range of resistance ratios were 13–26 fold for profenofos and 12–30 for triazophos. For the two biorational insecticides evaluated, the range of resistance ratio were 2.1–5.0 fold for emamectin benzoate and 15–20 fold for spinosad. A good insecticide rotation could be between insect growth regulators and neurotoxic insecticides to prevent resistance development in the E. vittella . IPM programs for controlling this pest should not be including broad spectrum insecticides, like most conventional ones, due to low selectivity of these active ingredients on natural enemies and pollinators.
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ABSTRACT Mealybug, Phenacoccus solenopsis Tinsley is a devastating pest of cotton and many other crops and ornamental plants. P. solenopsis has ability to develop resistance to most chemical classes of insecticides. The aim of present... more
ABSTRACT Mealybug, Phenacoccus solenopsis Tinsley is a devastating pest of cotton and many other crops and ornamental plants. P. solenopsis has ability to develop resistance to most chemical classes of insecticides. The aim of present study was to monitor the resistance to new chemical insecticides in different field populations of P. solenopsis. Six populations of P. solenopsis, collected from Multan, Khanewal, Muzaffar Garh, Mailsi, Bahawalpur, and Sahiwal, were tested for resistance to selected new chemical insecticides by the leaf dip method. The resistance ratios were in the range of 4.0e30.9-fold for nitenpyram, 12.6 e105.0-fold for acetamiprid, 3.4e79.0-fold for emamectin benzoate, 0.4e2.3 fold for indoxacarb, 12.1 e28.9 for pyriproxyfen, 13.0e37.4 for cyromazine, 7.2e35.0 for methoxyfenozide, and 5.5e17.0-fold for lufenuron compared to the laboratory susceptible strain. Regular insecticide resistance monitoring and integrated management plans including the judicious use of insecticides with correct application rates and methods and rotation of insecticides with different modes of action are required to delay insecticide resistance development in P. solenopsis.
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This paper presents a compact-sized rectangular slotted patch antenna which operates over Industrial, Scientific, and Medical (ISM) (2.40-2.48 GHz) band. This implantable antenna is fed by coaxial feed of $\mathbf{50}\ \Omega$. It is kept... more
This paper presents a compact-sized rectangular slotted patch antenna which operates over Industrial, Scientific, and Medical (ISM) (2.40-2.48 GHz) band. This implantable antenna is fed by coaxial feed of $\mathbf{50}\ \Omega$. It is kept in phantom skin tissue of dimensions $\mathbf{50x50x50}\ mm^{3}$. Simulation of this antenna is carried out through the High Frequency Structure Simulator (HFSS). By employing the shorting pin and open-ended slots; the proposed antenna has obtained an effective size reduction at a fixed frequency operation. As a result, the obtained peak gain is −14 dB and bandwidth is 290 MHz. The results show that the proposed antenna has effective size reduction, excellent performance, and Bandwidth due to which the antenna is used in Biotelemetry application.
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BACKGROUND Imidacloprid, a neonicotinoid insecticide, is widely sprayed alone or mixed with other insecticides against Dysdercus koenigii, a potential pest of cotton in Pakistan. Recently, resistance to imidacloprid in field populations... more
BACKGROUND Imidacloprid, a neonicotinoid insecticide, is widely sprayed alone or mixed with other insecticides against Dysdercus koenigii, a potential pest of cotton in Pakistan. Recently, resistance to imidacloprid in field populations of D. koenigii has developed because of its overuse. Herein, we have investigated inheritance of imidacloprid resistance in D. koenigii and its cross-resistance to other insecticides. RESULTS The imidacloprid selected population had a 91421-fold increase in resistance to imidacloprid after six generations. Overlapping 95% fiducial limits of LC50s of the F1 (Imida-Sel ♂ × Sus-ST ♀) and F1 † (Imida-Sel ♀ × Sus-ST ♂) suggested an autosomal and incomplete dominant resistance to imidacloprid (DLC = 0.84 for F1 and 0.86 for F1 † ). Reciprocal backcrosses of the F1 and F1 † with Sus-ST predicted a polygenic inheritance. Realized heritability of imidacloprid resistance was 0.38. When mean slope = 1.74 and h2 = 0.38, then 3-13 generations would be required for a ten-fold increase in LC50s at 90-20% intensity of selection. Very high cross-resistance to emamectin benzoate (143-fold), deltamethrin (1675-fold), lambda-cyhalothrin (140-fold), and moderate cross-resistance to acetamiprid (37-fold) in the imidacloprid-selected strain compared to the Field-Pop were observed. CONCLUSION Imidacloprid resistance developed very quickly under continuous selection pressure in the laboratory. These factors might lead to an increasing likelihood of resistance development in field populations, if imidacloprid is continuously used without insecticide rotation for prolonged periods. The present results would be supportive for better management of D. koenigii by devising an effective resistance management strategy. This article is protected by copyright. All rights reserved.
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This review article encapsulates the recent developments in the metal-free approaches used to construct oxazole moiety.
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Drug development has been a principal driving force in the rapid maturation of the field of medicinal chemistry during the past several decades. During this period, the intriguing and challenging molecular architectures of... more
Drug development has been a principal driving force in the rapid maturation of the field of medicinal chemistry during the past several decades. During this period, the intriguing and challenging molecular architectures of nitrogen-containing heterocycles with potential bioactive properties have received significant attention from researchers engaged in the areas of natural product synthesis and heterocyclic methodology, and constituted a continuous stimulus for development in bio(organic) chemistry. In this perspective, the current review article is an effort to summarize recent developments in the environmentally benign synthetic methods providing access to quinazoline and quinazolinone scaffolds with promising biological potential. This article also aims to discuss potential future directions on the development of more potent and specific analogues for various biological targets.
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Today, machine learning based on neural networks has become mainstream, in many application domains. A small subset of machine learning algorithms, called Convolutional Neural Networks (CNN), are considered as state-ofthe- art for many... more
Today, machine learning based on neural networks has become mainstream, in many application domains. A small subset of machine learning algorithms, called Convolutional Neural Networks (CNN), are considered as state-ofthe- art for many applications (e.g. video/audio classification). The main challenge in implementing the CNNs, in embedded systems, is their large computation, memory, and bandwidth requirements. To meet these demands, dedicated hardware accelerators have been proposed. Since memory is the major cost in CNNs, recent accelerators focus on reducing the memory accesses. In particular, they exploit data locality using either tiling, layer merging or intra/inter feature map parallelism to reduce the memory footprint. However, they lack the flexibility to interleave or cascade these optimizations. Moreover, most of the existing accelerators do not exploit compression that can simultaneously reduce memory requirements, increase the throughput, and enhance the energy efficiency. To tackle these limitations, we present a flexible accelerator called MOCHA. MOCHA has three features that differentiate it from the state-of-the-art: (i) the ability to compress input/ kernels, (ii) the flexibility to interleave various optimizations, and (iii) intelligence to automatically interleave and cascade the optimizations, depending on the dimension of a specific CNN layer and available resources. Post layout Synthesis results reveal that MOCHA provides up to 63% higher energy efficiency, up to 42% higher throughput, and up to 30% less storage, compared to the next best accelerator, at the cost of 26-35% additional area.
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Spontaneous splenic rupture is an uncommon but life threatening acute emergency. Up to one half cases of Atraumatic splenic rupture (ASR) are preceded by splenomegaly. Hematological malignancies can present with splenomegaly and have... more
Spontaneous splenic rupture is an uncommon but life threatening acute emergency. Up to one half cases of Atraumatic splenic rupture (ASR) are preceded by splenomegaly. Hematological malignancies can present with splenomegaly and have clinical features of left upper quadrant (LUQ) pain and fullness. Abdominal pain is one of the commonest reasons for consulting Gastroenterology in the in-patient setting. We present a case of a patient who developed symptoms due to ASR which was not evident on initial imaging. While there are multiple causes of ASR, neoplastic etiologies account for about a third of these cases. Hairy Cell Leukemia (HCL) is a rare lymphoid neoplasm which oft en presents with nausea, vomiting, and LUQ pain. Splenomegaly is a common manifestation of this disease, although ASR occurs much less frequently. Th is report highlights a case of a 64-year-old woman with known comorbidities of hypertension and diabetes, who presented with persistent nausea, vomiting and epigastric pain, for one week. Prior to presentation, she had complained of intermittent abdominal pain for 16 months. A computerized tomography (CT) scan of abdomen done a year earlier had revealed a nonspecifi c wedgeshaped, low attenuating lesion in the spleensuspicious for a splenic infarct. On examination, she was hemodynamically stable, with mild discomfort in the LUQ and palpable splenomegaly which was confi rmed by imaging studies. Th e patient was thought to have gastroparesis secondary to uncontrolled diabetes mellitus, and was being treated conservatively. Patient was then noted to have a signifi cant drop in Hematocrit without signs of active gastrointestinal bleeding. Her abdomen became distended with moderate LUQ tenderness. A repeat CT scan of abdomen showed evidence of intraperitoneal hemorrhage. Th e patient underwent emergent angiography and a bleeding splenic vessel was identifi ed and embolized. She underwent an open splenectomy for ASR. A 6 cm laceration was found on the lower pole of the spleen. Pathology of the specimen unexpectedly returned positive for HCL. Patients with splenomegaly oft en present with symptoms of nausea, vomiting, and minimal LUQ tenderness. Careful clinical evaluation and urgent investigations should be undertaken in these patients as they may develop serious complications. ASR is an important and life threatening complication which may develop acutely or insidiously and should be monitored for in any patient with splenomegaly of unknown cause.
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Experiments have been conducted using Water only cyclone to reduce ash in coal from Cherat region of Khyber Pakhtunkhwa in Pakistan, varying the associated design and operation parameters. These parameters were optimized on the bases of... more
Experiments have been conducted using Water only cyclone to reduce ash in coal from Cherat region of Khyber Pakhtunkhwa in Pakistan, varying the associated design and operation parameters. These parameters were optimized on the bases of yield and the ash percent in clean coal. It was observed that the vortex finder diameter has a greatest effect on the clean coal yield. The selected optimum parameter values were cyclone inclination 30 degree, cyclone inlet pressure 100 kPa, vortex finder diameter 54 mm, apex diameter 26 mm, solid feed concentration 18% and the vortex finder length 240 mm. By optimization the operating and design parameters of Water only cyclone the clean coal of less than 15% ash was produced from 30% raw coal ash. The indigenous coal of the above given specification can be utilized in cement industry.
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The presence of heterocycles and heteroaromatics as ubiquitous components in a diverse variety of synthetic drugs, biologically active molecules, and natural products has inspired the researchers to develop new strategies and technologies... more
The presence of heterocycles and heteroaromatics as ubiquitous components in a diverse variety of synthetic drugs, biologically active molecules, and natural products has inspired the researchers to develop new strategies and technologies for their easy accessibility. Among them, six membered nitrogenous heterocycles gained immense interest, and significant efforts have been made to the development of synthetic strategies which could lead to the discovery of architecturally complex and diverse molecules with high efficiency, low cost, less organic waste and shorter reaction time. Access to such systems by one-pot multi-component approach with inherent advantages of step-economy, operational simplicity, synthetic efficiency, and environmental compatibility is particularly attractive. The current review article highlights the recent developments in the synthesis of six membered nitrogen-containing heterocyclic scaffolds through one-pot multi-component assembly approach.
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The palladium‐catalyzed exhaustive Suzuki‐Miyaura cross‐coupling reaction gives access to various multiarylated fluorobenzenes with interesting optical properties.