Seroprevalence of <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> in sheep and goats in Rahim Yar Khan (Punjab), Pakistan

Toxoplasmosis, an infection caused by Toxoplasma (T.) gondii Apicomplexa protozoan, is widespread in humans and other animal species, having already been reported in many countries and different climates. In Pakistan, no data is available on this aspect among food animals. This study was undertaken to determine the seroprevalence of T. gondii infection in sheep and goats. A total of 200 serum samples from sheep and goats, were collected from urban area of Rahim Yar Khan (Punjab), Pakistan and tested for Toxoplasmosis with a commercial latex agglutination kit (Eiken Chemical Co., Ltd. Japan). The overall seroprevalence of Toxoplasmosis was 19%. Goats had a significantly higher (p < 0.01) prevalence (25.4%) as compared to the sheep (11.2%); and higher (p < 0.01) in the female (24%) than in the males (19%) for both species. In the present study the male (both in sheep and goat) are found less seropositive T. gondii (OR = 0.23; 99% C.I. = 0.01, 1.81) as compared to female sheep and goat. The prevalence was significantly higher (p < 0.01) in adult sheep than younger animals. Among both the sheep and goats the group from 1–1.5 years are highly seropositive (OR = 1.75; 99% C.I. = 0.47, 6.51) as compared to the group less than one year of age followed by the 2–2.5 years age group (OR = 1.63; 99% C.I. = 0.50, 5.74) whereas group with more than 3 years of age least seropositive.     

Effect of induced pyrexia on the disposition kinetics of ciprofloxacin in dogs

Ciprofloxacin was administered intravenously @ 5 mg/kg body weight to six healthy dogs. After a washout period of two weeks, fever was induced by injecting Escherichia (E) coli endotoxin. Ciprofloxacin was administered again. Blood samples were collected at various time intervals and analyzed for ciprofloxacin with HPLC. The kinetic analysis revealed the volume of distribution in healthy vs. febrile dogs as 2.12 ± 0.32 vs. 1.79 ± 0.43 L/Kg, respectively. The elimination half life was 2.23 ± 0.78 and 2.07 ± 0.74 hours in healthy and febrile dogs, respectively. Similarly, dogs under healthy and febrile conditions showed comparable total plasma clearance of 0.66 ± 0.06 and 0.60 ± 0.07 L/Kg/h, respectively. All these and other investigated kinetic parameters were statistically non significant. This study concludes that the pharmacokinetic behavior of ciprofloxacin is similar under healthy and febrile conditions. Thus, the kinetic studies of fluoroquinolones conducted in normal/healthy animals may be used to depict the pharmacokinetic parameters in diseased animals.     

Prallethrin induced serum biochemical changes in Wistar rats

The present study was designed as a repeated dose 28-day oral toxicity study in rodent. All the rats were randomly divided into five groups (C1, C2, T1, T2 and T3) each containing 10 Wistar rats (5 male and 5 female). Group C1 served as control as no treatment was administered. Group C2 was administered groundnut oil (1 ml/100 g b.wt) and served as vehicle control. Group T1 was put on high dose 153.33 mg/kg b.wt (LD50/3), while group T2 received intermediate dose of 92 mg/kg b.wt (LD50/5), and group T3 was administered low dose of 46 mg/kg b.wt (LD50/10) of Prallethrin suspended in 1 ml/100 g b.wt of groundnut oil. Blood samples were collected from all groups on the 7th, 14th, 21st and 28th day of the experiment for measurement of serum glucose, serum urea, serum triglyceride, serum cholesterol, serum aspartate aminotransferase (AST), serum alanine aminotransferase (ALT) and serum alkaline phosphatase (ALP). According to data obtained on the 7th day of the study, no statistically significant change in any of the treatment groups was observed as compared to the control group. On the 14th day of the study, in comparison to the control group, triglyceride level and ALP activity were found to be significantly increased in the group T1 female and group T1 male rats respectively. On the 21st day of the study, compared to the controls, significant increase in cholesterol and ALP levels were present in both T1 and T2 females and in addition to this total protein and triglycerides levels were also significantly increased in group T1 female rats. In group T1 male total protein, triglycerides, ALT and ALP activity was found to be increased significantly as compared to healthy control group. On the 28th day, all the recorded biochemical parameters were found to be significantly increased, except BUN and AST in group T1 female rats. In group T2 female rats, significantly increased cholesterol, ALT and ALP levels were observed. In group T3 female rats, none of the parameters were found to be significantly affected. Among male rats, only total protein level was found to be increased in groups T2 and T3. Whereas, total protein, triglyceride, ALT and ALP were significantly elevated in group T1 male rats at the end of the study. In conclusion, the results of this study demonstrate that subacute oral administration of Prallethrin; at dose levels of 1/3 LD50 and 1/5 LD50 for 28 days induces moderate toxic effects on different biochemical parameters.     

Molecular characterization, ecology, and epidemiology of a novel Tymovirus in Asclepias viridis from Oklahoma

Native virus-plant interactions require more understanding and their study will provide a basis from which to identify potential sources of emerging destructive viruses in crops. A novel tymovirus sequence was detected in Asclepias viridis (green milkweed), a perennial growing in a natural setting in the Tallgrass Prairie Preserve (TGPP) of Oklahoma. It was abundant within and frequent among A. viridis plants and, to varying extents, within other dicotyledonous and one grass (Panicum virgatum) species obtained from the TGPP. Extracts from A. viridis containing the sequence were infectious to a limited number of species. The virus genome was cloned and determined to be closely related to Kennedya yellow mosaic virus. The persistence of the virus within the Oklahoma A. viridis population was monitored for five successive years. Virus was present in a high percentage of plants within representative areas of the TGPP in all years and was spreading to additional plants. Virus was present in regions adjacent to the TGPP but not in plants sampled from central and south-central Oklahoma. Virus was present in the underground caudex of the plant during the winter, suggesting overwintering in this tissue. The RNA sequence encoding the virus coat protein varied considerably between individual plants (≈3%), likely due to drift rather than selection. An infectious clone was constructed and the virus was named Asclepias asymptomatic virus (AsAV) due to the absence of obvious symptoms on A. viridis.     

Excretion,distribution and depletion of [14C]cypermethrin and cis and trans isomers of 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid administered orally to laying hens

Radiolabelled racemic cypermethrin, and the cis and trans isomers of 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid (labelled at C-1 of the cyclopropane ring) were each separately administered orally in feed for three consecutive days to White Leghorn laying hens. The amount of individual compound dosed was approximately 7.5 mg per hen per day. Radiocarbon was eliminated very rapidly in excreta. Tissue residues were generally very low with the exception of fat depots, but trace amounts of radiocarbon residues were still detectable in fat, liver and kidney 11 days post-treatment. Residues were detected in the egg albumen of hens treated with cypermethrin and cis isomer of the acid, but none was detected from trans acid. Metabolites identified included products arising from the hydrolysis of the ester bond of cypermethrin, followed by oxidative attack on one or both methyl groups. The rate of oxidative attack on methyl groups was influenced by the geometry of the dichlorovinyl group. On the basis of the metabolites identified a metabolic pathway for cypermethrin in laying hens was proposed which included hydrolysis of the ester bond followed by oxidation of methyl group(s). The data indicate that use of cypermethrin as recommended should not produce residues in eggs and meat of laying hens at levels that are of toxic concern.     

Effect of waste water and fly ash application on physiological determinants,yield, and heavy metal contents of yellow mustard (B. campestris cv. P. Gold)

A pot experiment was conducted to study the comparative effect of waste water (WW) and ground water (GW) alone and along with different nitrogen (N), phosphorus (P), and potassium (K) combinations (N₀P₀K₀, N₄₀P₁₅K₁₅, N₆₀P₃₀K₃₀, N₈₀P₄₅K₄₅) together with different levels of fly ash (FA) (FA₀, FA₁₀, FA₂₀), to obtain a suitable combination of fertilizers, FA and water based on the growth, physiology, yield, and heavy metal contents of Brassica campestris cv. Pusa Gold. Results revealed that WW irrigation proved beneficial over GW. All the parameters increased in both levels of FA₁₀ and FA₂₀ along with three doses of NPK but FA at 20 t ha^?1 proved better. The effect was more efficacious with both wastes together which makes NPK optimum at N₆₀P₃₀K₃₀ instead of N₈₀P₄₅K₄₅ treatment combinations and thereby lowered input of fertilizers. Therefore, utilization of these wastes may be recommended for the purpose of irrigation, soil amendment, and as a source of nutrients in augmenting the mustard yield.     

Histomorphological changes in digestive tract of golden mahseer (<Emphasis Type="Italic">Tor putitora</Emphasis>) during different developmental stages

Histomorphological changes in digestive tract of golden mahseer (Tor putitora) were examined in larvae [starting from hatching to 45 days post-hatching (dph)], fry, fingerling, and adult. Digestive tract appeared during hatching, on the dorsal side of yolk sac, as a straight tube with a narrow lumen. Mouth opening and appearance of liver and pancreas were observed at 2 dph, and subsequently anal opening, appearance of goblet cells in esophagus, and posterior intestine were evident at 3 dph. The remodeling of oral cavity in terms of epithelial stratification, appearance of taste buds, and goblet cells were observed in a window of 4–5 dph. Intestinal folding was found to be initiated at 8 dph. From 12 to 45 dph, thickening of oral and esophageal mucosal/extramucosal layers, increase in intestinal folding, increases in the density of goblet cells in entire gut were observed. Within the same time window, other histological changes such as disappearance of vacuoles in liver, and abundance of zymogen granules in pancreas were also observed. Supranuclear vesicles in mid-to-posterior intestine were found to be prominent from first feeding to 45 dph; however, this phenomenon was no longer evident in fry and fingerling. Overall, the increase in intestinal folding and complexity of extramucosal layer were found to be continuous from the first appearance to adult, and this inferred the fact that the nutritional physiology, in terms of digestion and assimilation, progressively changes throughout the life stages of golden mahseer. Findings of this study will, therefore, help in preparing diets for different life stages of this fish, and in addition, the present information widens the understanding of digestive physiology of golden mahseer.     

POTATO TUBER YIELD AND QUALITY AS AFFECTED BY RATES AND SOURCES OF POTASSIUM FERTILIZER

Among the major nutrients, potassium (K) not only improves yields but also improves quality parameters. Field experiments were conducted to assess the comparative effect of sources and rates of K fertilizer on potato yield and quality on a sandy loam soil. Graded doses of potassium, i.e., 0, 150 and 225 kg ha^?1 K₂O from sulfate and muriate of potash were applied in triplicate. Recommended dose of nitrogen (N) and phosphorus (P) applied uniformly. Significant increase in tuber yield was observed with 150 kg ha^?1 K₂O from both the sources over control. Increase in tuber yield with 225 kg ha^?1 K₂O was statistically non significant compared to 150 kg ha^?1. The dry matter and specific gravity were more affected with sulfate of potash (SOP) than muriate of potash (MOP). The quality parameters like dry matter, specific gravity, starch contents, vitamin C, chips color and taste were improved with K application.     

A new equation to simulate the contact between soil and maize residues of different sizes during their decomposition

The availability of soil nutrients, which are recycled through the decomposition of crop residues, is important for the management of cropped soils. However, knowledge regarding the influence of contact between crop residues and soil on the dynamics of carbon (C) and nitrogen (N) in soil is limited. In particular, the effect of particle size on decomposition is not well-known, and conceptual approaches for modelling the soil-residue contact in a decomposition model remain scarce. Therefore, we analysed and modelled the effect of maize stem particle length on decomposition. We incubated maize stem residues with particle sizes of 0.02, 0.5, 2 and 5 cm in length in a loamy soil at 25 °C over 301 days. We continuously measured the mineralisation of C and N and determined the chemical evolution of the remaining particles. We used the decomposition model CANTIS which takes into account the soil-residue contact, using a contact factor, K_MZ. The decomposition rates of smaller maize particles were higher than those of larger particles during the early phases of decomposition. However, these differences were not maintained after 301 days. These results suggest that a larger size of the maize particles only slowed the rate of mineralisation in the short term but did not modify decomposition in the medium term. We proposed a new formalism for expressing the changes in soil-residue contact with different particle sizes. The contact factor K_MZ was calculated using the standardised specific surface area and can be applied more widely to residues that differ in morphology and density.