scholarly journals Effects of the organophosphorous methyl parathion on the branchial epithelium of a freshwater fish Metynnis roosevelti

2003 ◽  
Vol 46 (3) ◽  
pp. 361-372 ◽  
Author(s):  
Marcelo Rubens Machado ◽  
Edith Fanta
Keyword(s):  
Methyl Parathion ◽  
Ionic Balance ◽  
Secondary Effects ◽  
Organophosphorous Compound ◽  
Nitrogenous Compounds ◽  
Main Site ◽  
Fish Samples ◽  
Gradual Disappearance ◽  
Sublethal Doses ◽  
Branchial Epithelium

Gills are vital structures for fish, since they are the main site for gaseous exchange as well as partially responsible for osmorregulation, acid-basic balance, excretion of nitrogenous compounds and taste. Chemicals in the water may alter the morphology of branchial cells of fish that are, therefore, a useful model for environmental impact and ecotoxicology studies. In order to investigate the effects of an organophosphorous compound, methyl parathion, on the gills of the fish, samples of Metynnis roosevelti were exposed to lethal (7ppm) and sublethal (1ppm) doses of Mentox 600 CE. Through light and scanning electron microscopy, shrinking of the branchial epithelium, followed by detachment and hyperplasia were observed. Externally, the branchial filaments presented the gradual disappearance of microridges. Even in sublethal doses, the organophosphorous reduced the health and fitness of these fish, as consequence of secondary effects derived from changes in the branchial epithelium, impairing oxygenation and ionic balance of the organism.

scholarly journals Urea nutrition of young maize and sugar-beet plants with emphasis on ionic balance and vascular transport of nitrogenous compounds.

1982 ◽  
Vol 30 (4) ◽  
pp. 317-330 ◽  
Author(s):  
M.L. van Beusichem ◽  
J.J. Neeteson
Keyword(s):  
Sugar Beet ◽  
Ionic Balance ◽  
Proton Extrusion ◽  
N Content ◽  
Nitrogenous Compounds ◽  
Xylem Exudate ◽  
Vascular Transport ◽  
N Sources ◽  
Significant Difference ◽  
Pot Trial

In a pot trial, maize cv. Prior and sugarbeet cv. Polyrave were given N as urea or ammonium. There was no significant difference between DM producton in either spp. with the different N sources, although plant N content was increased with N supplied as ammonium. Root cumulative net proton extrusion closely agreed with calculated values for net absorption of cations, indicating that urea was absorbed intact, at a rate sufficient for growth. Xylem exudate was free from urea and NH3-N suggesting metabolism in the roots. Urea appeared to be assimilated other than by enzymic breakdown. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Influence of Sublethal Doses of Permethrin and Methyl Parathion on Dispersal Behavior of Two Species of Spider Mites (Acari: Tetranychidae) on Corn

1995 ◽  
Vol 24 (2) ◽  
pp. 226-232 ◽  
Author(s):  
Ramesh Ayyappath ◽  
John F. Witkowski ◽  
Leon G. Higley ◽  
Blair D. Siegfried
Keyword(s):  
Methyl Parathion ◽  
Spider Mites ◽  
Dispersal Behavior ◽  
Sublethal Doses

Variations in Surface Textures of Quartz Sand using Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 494-495
Author(s):  
Eugene J. Amaral
Keyword(s):  
Electron Microscopy ◽  
Glass Industry ◽  
Glass Slide ◽  
Distilled Water ◽  
Early Paleozoic ◽  
Secondary Effects ◽  
Surface Textures ◽  
High Silica ◽  
Sand Deposit ◽  
The U.S

Examination of sand grain surfaces from early Paleozoic sandstones by electron microscopy reveals a variety of secondary effects caused by rock-forming processes after final deposition of the sand. Detailed studies were conducted on both coarse (≥0.71mm) and fine (=0.25mm) fractions of St. Peter Sandstone, a widespread sand deposit underlying much of the U.S. Central Interior and used in the glass industry because of its remarkably high silica purity.The very friable sandstone was disaggregated and sieved to obtain the two size fractions, and then cleaned by boiling in HCl to remove any iron impurities and rinsed in distilled water. The sand grains were then partially embedded by sprinkling them onto a glass slide coated with a thin tacky layer of latex. Direct platinum shadowed carbon replicas were made of the exposed sand grain surfaces, and were separated by dissolution of the silica in HF acid.

N transfer from white clover to perennial ryegrass, via exudation of nitrogenous compounds

Agronomie ◽  
2003 ◽  
Vol 23 (5-6) ◽  
pp. 503-510 ◽  
Author(s):  
Florence Paynel ◽  
Jean Bernard Cliquet
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
N Transfer ◽  
Nitrogenous Compounds

PHYTOCHEMICAL SCREENING AND LARVICIDAL EFFECT EVALUATION OF AZADIRACHTA INDICA (L) LEAF EXTRACT ON DERMESTES MACULATUS (DE GEER, 1774) INFESTATION OF SMOKED CLARIAS GARIEPINUS (BURCHELL, 1822)

2020 ◽  
Vol 4 (2) ◽  
pp. 41-45
Author(s):  
Sadam Sulaiman Indabo ◽  
Rufai Zakari
Keyword(s):  
Azadirachta Indica ◽  
Leaf Extract ◽  
Standard Procedure ◽  
Clarias Gariepinus ◽  
Phytochemical Screening ◽  
Range Finding ◽  
Dermestes Maculatus ◽  
Randomized Design ◽  
Fish Samples ◽  
Initial Source

Dermestes maculatus is a major pest of stored fish in Nigeria, fish is preserved with highly persistent synthetic chemicals. There have been an increasing effort at developing plant-based toxicants that are environmentally friendly. Therefore, this study was conducted to screen the leaf extract of Azadirachta indica for phytochemical constituents. The efficacy of the methanolic leaf extract of the plant against D. maculatus was also evaluated. The leaves of A. indica were obtained, processed and taken to laboratory for methanolic extraction. Phytochemical screening was carried out to identify saponins, flavonoids, alkaloids, tannins, steroids, cardiac glycosides, glycosides, triterpenes and carbohydrates using standard procedure.  Both clean and infested samples of smoke-dried Clarias gariepinus were purchased from Sabon Gari Market, Zaria. The infested samples were used as initial source of D. maculatus larvae. Range finding test was carried out prior to the bioassay. During the bioassay, clean un-infested fish samples were weighed and introduced into kilner jars and respective dosages of 0.2g, 0.4g, 0.6g and 0.8g of extract were added. Another set of fish samples without the extract were maintained as control. The experiment was arranged in Completely Randomized Design with three replicates. Fifteen larvae of D. maculatus were introduced into both treated and control containers and covered. Mortality was recorded after 24, 48, 72 and 96 hours. Data obtained revealed an increase in mortality with increasing dose and time. Mortality ranged from 1.67 to 11.00. Therefore, leaf extract of A. indica should be incorporated in the development of larvicide against D. maculatus.   

Effects of Drying Methods on the Biochemical Composition and Organoleptic Properties of Two Freshwater Fish Species (Mormyrus rume and Labeo coubie) of Cross River Obubra, Nigeria

2019 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Moisture Content ◽  
Fish Species ◽  
Nutrition Status ◽  
Drying Methods ◽  
Organoleptic Properties ◽  
Nutrient Quality ◽  
Oven Drying ◽  
Fish Samples ◽  
Fish And Fishery Products ◽  
Mormyrus Rume

Consumers all over the world are increasingly becoming aware of the health and nutrition status of fish and fishery products. There have develop some preference for fish species and even their processing methods. This study aims to investigate the effects of two drying methods (smoking and oven drying) on the biochemical components and organoleptic properties of two less preferred food fishes abundant in the study area. The fish samples Mormyrus rume and Labeo coubie were purchased from fresh landings of fishermen at Ahaha beach. The biochemical assay of the moisture, protein, fat, carbohydrate, ash, calcium (Ca), magnesium (Mg), phosphorus (P), iron (Fe), sodium (Na) and potassium (K) were conducted in the labouratory using standard methods. The proximate composition of raw M. rume was determined as moisture 70.38%, protein 17.43%, carbohydrate 1.13%, fat 5.93% and ash 2.77% while oven dried were 18.78, 63.85, 3.37, 8.73 and 7.58% respectively. All the proximate parameters and gross energy level investigated were higher (p < 0.05) in M. rume except the moisture content of dried samples of L. coubie. The mineral content were in the order Ca < Mg < Fe < Na < P and < K in both species and were higher in M. rume except Na. The drying methods showed increase in the proximate and mineral compositions in the order raw < smoking and < oven drying except moisture content that decreased respectively is both species. Organoleptic properties revealed that dried samples (smoked and oven) were not significantly different (p < 0.05) in taste, flavour, texture and overall acceptance, however while oven dried had better colour (4.33), smoked dried taste (4.63) better. The drying methods shows concentration of the required nutrients in human diets and were also found to be most palatable by the panellist. To improve fish nutrient quality smoke and oven drying should be encourage.

The Rain Calls of Frogs and the Reigning Paradigm of American Herpetology

2020 ◽  
pp. 1-35
Author(s):  
Gordon L. Miller
Keyword(s):  
Twentieth Century ◽  
Animal Communication ◽  
The United States ◽  
Emotional States ◽  
Breeding Sites ◽  
Gradual Disappearance ◽  
The Times ◽  
Traditional Natural ◽  
Breeding Seasons ◽  
The Comparative Study

American zoologists and herpetologists during the past fifty years have successfully deciphered the mating calls of frogs and toads with ever increasing precision and sophistication. However, the vocalizations most commonly termed “rain calls,” which typically occur beyond both normal breeding seasons and breeding sites, have remained a persistent puzzle. This article traces the gradual disappearance of rain calls, along with a corresponding decline in any mention of emotional states, from herpetological studies of anuran vocalizations in the United States from the middle of the twentieth century to the present and examines the historical roots of this disappearance. This evaporation of rain calls is indicative of a much larger change in the scientific climate of the times involving the transition from traditional natural history to the Neo-Darwinian, adaptationist paradigm of contemporary biology. Rain calls thus increasingly became anomalous, thereby eliminating a possibly fruitful line of inquiry in the comparative study of human-animal communication, in this case with evolution's earliest vocalizers. The contours and benefits of a more encompassing paradigm, envisioned by some leading early twentieth-century zoologists, are briefly discussed.

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