Bt and Gypsy Moth Essay Example | Topics and Well Written Essays - 1000 words

Bt and Gypsy Moth - Essay Example trees. Sparks, Michaels and Daniels (2013) reiterate that the larvae of Lymantria dispar have often caused significant defoliation in the past. Lymantria dispar’s life cycle usually start over the season of winter when the insects lay large masses of eggs. Ruiu and Roberto (2013) reiterate that these eggs hatch in generous numbers over the seasons of spring. Lymantria dispar represents a noteworthy risk to forests in various parts of the world. Preservation of the Cork Oak Forest would require implementation of proper management programs. In the past, forest conservation bodies have often considered several management approaches to control the adverse effects of Lepidopteran defoliators. However, some biological and practical limitations have of alternative pest control methods to contain the infestation of the defoliators over large tracks of lands have been observed. Currently, environmental conservation bodies have concentrated on the use of entomopathogenic microorganisms such as Bacillusthuringiensis (Btk) given the reason that these organisms’ impacts can be felt over large areas. Bacillusthuringiensis (Btk) products have become increasingly crucial as integrated means of pest management and are incessantly being employed in the control of pests in agro systems and forests around the globe. Bacillusthuringiensis (Btk) formulae that are used in the control of Lepidoptera consist of a concoction that includes parasporal bodies such as crystals and bacterial spores. The parasporal bodies contain insecticidal toxins such as the cry proteins. In the view of Sparks, Michaels and Daniels (2013), the gypsy moths consume the proteins which become activated after they are injected into their bodies. The proteins then become bound to specific plasma membrane receptors on the midgut section of the insect pests; epithelium. They sip into the cell membrane and determine the formation of

A research into Sick Building Syndrome who suffers more male or female Coursework - 1

A research into Sick Building Syndrome who suffers more male or female - Coursework Example When twenty percent or more of a building’s occupants complain of these conditions, it is said that these individuals may be suffering from sick building syndrome (Akovali, 2007). Sick building syndrome is described as a condition wherein a group of people in the same building or similar structure experiences acute health symptoms which improves or disappears once they go out of the building. These symptoms include headache; irritated eyes, nose, and throat; cough; dry and itchy skin; dizziness and nausea; inability to concentrate; sensitivity to odours; and fatigue. Its underlying cause remains unclear. However most attribute the phenomenon to inadequate building ventilation, contaminants and stress (Fraser, 2008). According to the study by Bischof and Bullinger (1998), symptoms of sick building syndrome were reported on both air-conditioned and naturally-ventilated buildings. However, incidents of SBS were more evident in poorly maintained air-conditioned buildings. Inadequate building ventilation. At the start of the 20th century, building ventilation standards set the ventilation rate to 15 cubic feet per minute per occupant. However, the oil crisis in the 1970s caused a reduction of ventilation rates to 5 cfm. The reduced flow of outdoor air was discovered to cause discomfort and acute health symptoms among the building’s occupants. In order to minimize energy use and attain an acceptable Indoor Air Quality level, the American National Standards Institute / American Society of Heating, Refrigerating, and Air-Conditioning Engineers had updated its ventilation standard to 20 cfm for office spaces (Environmental Protection Agency, 1991). Airborne contaminants. Ventilation systems for office buildings usually acquire air from the outside. As outdoor air gets inside the building, it also brings airborne contaminants. Sources of contaminants include motor vehicle fumes, plumbing and building exhausts;