31 research outputs found
Fumigant Toxicity and Oviposition Deterrency of the Essential Oil from Cardamom, Elettaria cardamomum, Against Three Storedâproduct Insects
Use of insecticides can have disruptive effects on the environment. Replacing the chemical compounds in these insecticides with plant materials, however, can be a safe method with low environmental risk. In the current study, chemical composition and insecticidal activities of the essential oil from cardamom, Elettaria cardamomum L. (Maton) (Zingiberales: Zingiberaceae) on the adults of three stored product pests was investigated. Results indicated that essential oil of E. cardamomum toxic to the bruchid beetle, Callosobruchus maculatus Fabricius (Coleoptera: Bruchidae), the red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), and the flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). Adults of E. kuehniella were more sensitive than the Coleoptera. Also, the highest mortality of these insects was seen after 12 hours. Results of the LT50 tests showed that the lethal time of mortality occurred between 10â20 hours in various test concentrations. Essential oil of E. cardamomum had a good efficacy on oviposition deterrence of C.
maculatus females, too. The chemical constituents of the essential oils were analyzed by gas chromatographyâmass spectrometry. The major constituents of cardamom were identified as 1,8-cineol, α-terpinyl acetate, terpinene and fenchyl alcohol. These results suggest that essential oil of E. cardamomum is a good choice for control of stored product pests
Approaches in biotechnological applications of natural polymers
Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento CientfĂico e TecnolĂłgico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de NvĂel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)
Ocular morbidity patterns among children in schools for the blind in Chennai
Purpose: To identify the morbidity patterns causing blindness in children attending schools for the blind in Chennai and comparing our data with similar studies done previously. Methods: A cross-sectional prevalence study was carried out in two schools for the blind in Chennai. Blind schools were visited by a team of ophthalmologists and optometrists. Students with best-corrected visual acuity (BCVA) worse than 3/60 in the better eye were included and relevant history was noted. Every student underwent anterior segment evaluation and detailed fundus examination. Morbidity of the better eye was taken as cause of blindness. Health records maintained by the school were referred to wherever available. Results: The anatomical causes of blindness include optic nerve disorders in 75 (24.8%) cases, retinal disorders in 55 (18.2%), corneal disorders in 47 (15.6%), lens-related disorders in 39 (12.9%), congenital anomalies in 11 (3.6%), and congenital glaucoma in 20 (6.6%) cases. The whole globe was involved in six cases (1.99%). Among conditions causing blindness, optic atrophy seen in 73 (24.17%) cases was the most common, followed by retinal dystrophy in 44 (14.56%), corneal scarring in 35 (11.59%), cataract in 22 (7.28%), and congenital glaucoma in 20 (6.6%) cases. Conclusion: It was found that avoidable causes of blindness were seen in 31% of cases and incurable causes in 45%. Optic nerve atrophy and retinal dystrophy are the emerging causes of blindness, underlining the need for genetic counseling and low vision rehabilitation centers, along with a targeted approach for avoidable causes of blindness