Larvicidal, Histopathological, Antibacterial Activity of Indigenous Fungus Penicillium sp. Against Aedes aegypti L and Culex quinquefasciatus (Say) (Diptera: Culicidae) and Its Acetylcholinesterase Inhibition and Toxicity Assessment of Zebrafish (Danio rerio)

Fungal metabolites are considered to be most efficient tools to overcome the issues related to insecticide resistance and environmental pollution. The present study focus on the evaluation of the mosquito larvicidal efficacy of metabolites of seven indigenous fungal isolates (Penicillium sp. Aspergillus niger, A. flavus, A. parasiticus, Rhizopus sp. Mucor sp. and Aspergillus sp.) on the larvae of Aedes aegypti and Culex quinquefasciatus under the laboratory condition. The preliminary screening of the isolate, Penicillium sp. showed better larvicidal effect when compared to other fungi. The fungus was grown on Potato Dextrose Broth (PDB) in the laboratory (at 25°C) and maintained in the relative humidity (at 76 ± 4% for 15 days). Larvicidal potency of mycelial ethyl acetate extract (MEAE) of Penicillium sp. was performed against 1st to 4th instars larvae of Ae. aegypti and Cx. quinquefasciatus using four different concentrations (100, 200, 300, and 500 μg/ml) that showed better larval mortality values (μg/ml) of LC50 = 6.554, 5.487, 6.874, 6.892, and the LC90 = 11.486, 10.366, 12.879, 13.865 for Ae. aegypti and LC50 = 7.000, 13.943, 18.129, 25.212 and the LC90 = 12.541, 23.761, 30.923, 41.696 for Cx. quinquefasciatus. Exposure of metabolite to larvae resulted in behavior changes i.e., excitation, up and down with aggressive movement, anal papillae biting behavior. Further, the larvae treated with Penicillium sp. metabolite exhibited significant reduction in the levels of acetylcholinesterase. The 4th instar mosquito larvae treated with the 500 μg/ml mycelia extract showed severe histological damages. During the antibacterial analysis of Penicillium sp.- mycelium the maximum growth inhibition zone was recorded in Shigella dysenteriae (31.2 mm) and Klebsiella pneumoniae (31.1 mm) followed by others. In addition, to check the toxicity of Penicillium sp. MEAE against embryos of Zebrafish, a model system, using different concentrations of metabolites (1.0, 0.5, 0.125 mg/ml, 30, 3.0, and 0.5 μg/ml) and life-stage parameters were observed at 124 hpf. Furthermore, the Fourier Transformed Infrared and GCMS spectrum analysis of mycelium reflected several chemical compounds. The outcome of the study clearly shows that Penicillium sp. metabolites could serve as an ideal eco-friendly, single-step and inexpensive source for the control of Ae. aegypti and Cx. quinquefasciatus larvae

The Relationship between Organisational Culture and Humanitarian Supply Chain Collaboration in Long-Term Aid

In recent times, there is an increase in the need for longterm aid. Since no actor can handle long-term aid alone, there is an increased need for collaboration between the actors. The actors in the long-term aid possess a variety of organisational cultures. Commercial supply chain literature informs that differences in organisational cultures between the partners in a supply chain lead to a strain in the collaborative relationship. In some instances, the differences result in ceasure of collaboration between partners. This thesis investigates the relationship between organisational culture and humanitarian supply chain collaboration in long-term aid. The aim of the thesis is to examine the influence of organisational culture on buyer-supplier collaboration in long-term aid. The thesis is both timely and relevant for a number of reasons. First, the increasing occurrence of natural and manmade disasters has led to a corresponding increase in long-term aid programmes. Second, longterm aid requires collaboration among multiple actors from differing organisational cultures. Finally, unlike commercial supply chain collaboration, this process has not yet been perfected in HSC contexts. The thesis investigates how differences of organisational culture influence collaboration in long-term HSC aid provision. This thesis takes a qualitative research approach. The findings included a framework that explains how organisational cultural attributes influence supply chain collaboration. The organisational leadership, or antecedent, influences organisational learning and organisational flexibility (organisational cultural elements). These elements influence information sharing (collaborative behaviour) through organisational routines. It can be further argued that there are four mechanisms through which organisational culture develops: organisational routines, organisational practices, organisational flexibility, and organisational learning. These mechanisms influence the mechanisms of supply chain collaboration: information sharing, trust, mutuality, and commitment. The thesis also finds the existence of humanitarian institutional logic as an overarching mechanism that mitigates the influence of organisational cultural differences on collaboration between actors

Investigating antireflection properties of hybrid silicon nanostructures comprising rod-like nanopores and nano-textured surface

In the present work, we have fabricated hybrid silicon (Si) nanostructures comprising vertical rod-like nanopores and nano-textured surface by metal assisted chemical etching (MACE) method at room temperature. The as-received p-type Upgraded Metallurgical grade (UMG) Si wafers were chemical polished, prior to investigating the etching effects at the metal nanoparticle semiconductor interface. The influence of metal silver nanoparticle (AgNPs) concentration on the formation of hybrid nanostructures were studied systematically. Depending on the surface morphology, the hybrid structures exhibited constant 10% average reflectance in the UV–Visible spectral region or average 7.5% reflectance in range of 200–400 nmsubmittedVersio

Influence of metal assisted chemical etching time period on mesoporous structure in as-cut upgraded metallurgical grade silicon for solar cell application

In this work, upgraded metallurgical grade silicon (UMG-Si) wafer was used to fabricate mesoporous nanostructures, as an effective antireflection layer for solar photovoltaic cells. The length of the vertical Si nanostructure (SiNS) arrays was altered by varying the etching time period during metal assisted chemical etching process, using a silver catalyst. The optical, structural, morphological changes and the antireflection properties of Si nanostructures formed on UMG-Siwafer were analysed. SEM and photoluminescence studies indicate that Si nanocrystals are formed on the surface and along the vertical nanowires. The pore size depends on the Ag nanoparticle size distribution. All the samples demonstrated a luminescence band centred around 2.2 eV. From the optical results, samples etched for 45 min show strong absorption in the visible spectrum. The minimum and maximum surface reflectance in the visible region was observed for 15 min and 60 min etched SiNS. Based on the observed results, 15 min etched Si with a uniform porous structure has minimum reflectance across the entire silicon UV–Vis absorption spectrum, making it worth further investigation as a candidate for use as an antireflection layer in silicon based solar cells

Investigating antireflection properties of hybrid silicon nanostructures comprising rod-like nanopores and nano-textured surface

In the present work, we have fabricated hybrid silicon (Si) nanostructures comprising vertical rod-like nanopores and nano-textured surface by metal assisted chemical etching (MACE) method at room temperature. The as-received p-type Upgraded Metallurgical grade (UMG) Si wafers were chemical polished, prior to investigating the etching effects at the metal nanoparticle semiconductor interface. The influence of metal silver nanoparticle (AgNPs) concentration on the formation of hybrid nanostructures were studied systematically. Depending on the surface morphology, the hybrid structures exhibited constant 10% average reflectance in the UV–Visible spectral region or average 7.5% reflectance in range of 200–400 n

DFT calculations as an efficient tool for prediction of Raman and infra-red spectra and activities of newly synthesized cathinones

AbstractInitially made for medical treatment for Parkinsonism, obesity, and depression, cathinones have become illegal drugs for the “recreational use”. The mechanism of action of synthetic cathinones consists of the inhibition of monoamine transporters. DFT (Density Functional Theory) calculations on the selected cathinones (3-FMC, 4-FMC, 4-MMC, Buphedrone, Butylone, Ethylone, MDPV, Methcathinone, and Methylone) were performed using B3LYP level of the Gaussian 09 program suite. The unscaled B3LYP/6–31G vibrational wavenumbers are in general larger than the experimental values, so the use of selective scaling was necessary. The calculated spectra of selected cathinones are in good correlation with the experimental spectra which demonstrates that DFT is a good tool for the prediction of spectra of newly synthesized and insufficiently experimentally characterised cathinones. Also, HOMO-LUMO (Highest Occupied Molecular Orbital-Lowest Unoccupied Molecular Orbital) analysis shows that 3-FMC possesses the minimum energy gap of 3.386 eV, and the molecule 4-FMC possesses the maximum energy gap of 4.205 eV among the investigated cathinones. It indicates that 3-FMC would be highly reactive among all the cathinones under investigation.</jats:p