Effect of synthetic juvenoid hormone (pyriproxyfen) on the larval stages and survival rates of fresh water prawn (Macrobrachium rosenbergii)

Possible effects of a synthetic juvenoid hormone (Pyriproxyfen) on larval development, metamorphosis and survival of a crustacean octopod, Macrobrachium rosenbergii, was studied. Although Pyriproxyfen is well known as an effective pest control product, our knowledge about its effects on crustacean metamorphosis, especially on larval stages is yet little. Macrobrachium rosenbergii is a suitable invertebrate species in the neurobiological and endocrinological researches. The species has II larval stages with obvious morphological features for every stage. In this study, larvae of the species were treated with 0.01, 0.05 and 0.1 ppm of Pyriproxyfen against a group of control for which xylene was used. In the first day of exposure to the Pyriproxyfen, all larvae were in the 1st larval stage. We studied the larval stages in samples obtained in different days and percentage of survival in the end of metamorphosis for treatment and control groups. The results showed that all concentrations of Pyriproxyfen significantly caused a delayed larval development and metamorphosis. Furthermore, the post larval survival rates of all treatment groups were less than control. These results suggest that synthetic juvenoid hormone retards the larval morphological development in Macrobrachium rosenbergii, and decreases the survival of the species

Correction factors determination for panoramic radiography using a phantom of mandible

"nBackground and Aim: Image distortion is one of the major problems in panoramic radiography. Horizontal and vertical correction factors could be determined for more efficient clinical applications. The purpose of this study was to determine horizontal and vertical correction factors in panoramic radiography. "nMaterials and Methods: In this test evaluation study in which an asymetric mandibular phantom was constructed by plexiglass and aluminium as soft and hard tissue equivalents. The right half was slightly shorter than the left half. Steel markers were installed to make vertical and horizontal measurments possible.The length of the markers as well as the intermarker distances were measured by Mitutoyo digital micrometer which was accurate within ±0.05mm. The phantom was then positioned in PM 2002 cc proline (Planmeca, Finland) panoramic machine and panoramic images were obtained. 8 times for each half of the phan. The same length and inter marker distances were measured on digitized panoramic images by Cygnus software, which was accurate whitin ±0.01 mm. Magnification and correction factors were determined for the vertical and horizontal dimensions in each region of pantomograms. "nResults: The mean vertical correction factor was 0.77±0.02 (range: 0.75-0.80) in the right and 0.77±0.05 (range: 0.75-0.85) in the left half jaw. The mean horizontal correction factor was calculated as 0.98±0.15 (range:"n0.76-1.18) in the right and 1.02±0.14 (range: 0.90-1.25) in the left half jaw. "nConclusion: Dissimilarity of vertical and horizontal correction factors among left and right half jaws and also in different regions of a half jaw is relatively considerable. However, a constant correction factor, specialy in horizontal aspect, could not be applicable. Comparing with horizontal correction factors the vertical correction factors showed less variations between different regions as well as different samples

Estimating Greenhouse Gas Emissions in the Pacific Island Countries

A national Greenhouse Gas Inventory (GHGI) outlines estimates of emissions of greenhouse gases (GHGs) from various sectors of a country such as energy, agriculture, forestry and other land use (AFOLU), waste and industrial processes and product use (IPPU). The accuracy and consistency of the inventory is a basic requirement to ensure reliability of the estimates so that opportunities for potential reductions could be realized that would eventually lead to the development of low emission scenarios to achieve near zero emissions by 2050. An analysis of the second national communications of Pacific Island Countries (PICs) to UNFCCC shows that most of the emissions from PICs are from the energy sector and probably explains why Fiji’s NDC Roadmap focuses on 30% emission reduction in the energy sector by 2030. This chapter discusses the IPCC 2006 guidelines to estimate emissions of CO2 and other non-CO2 greenhouse gases from different sectors. The uncertainties in emission estimates are discussed with more focus on data availability in the PICs. Research needed to derive country specific emission factors are also highlighted for certain sectors