A STEPWISE COMPUTER PROGRAM FOR ESTIMATING DEVELOPMENT TIME AND SURVIVAL OF AEDES VEXANS (DIPTERA: CULICIDAE) LARVAE AND PUPAE IN FIELD POPULATIONS IN SOUTHERN ALBERTA

1979 ◽  
Vol 111 (11) ◽  
pp. 1241-1253 ◽  
Author(s):  
J. D. Slater ◽  
G. Pritchard

AbstractGrowth and survival rates for larvae and pupae of Aedes vexans (Meigen) were measured in the laboratory at constant temperatures of 10°, 15°, 20°, 25°, and 30 °C. Growth rates in all stages increased with temperature except for 1st stage larvae which developed marginally faster at 25°C than at 30°C. The shortest stage at all temperatures was the 2nd, followed in most cases by the 3rd, 1st, and 4th larval stages, and then pupae; pupae and 4th stage larvae took markedly longer to develop at low temperatures. Average survival rate was about 99% every 3 h for larvae and 98% for pupae. At 10° and 15°C, 1st and 2nd stage larvae survived no better than later stages, but at the higher temperatures survival to the 3rd stage larva was better than 90% but decreased markedly in the 3rd and 4th stages. Overall survival was highest at 25°C. Mosquitoes reared at 10°C did not pupate, while those reared at 30 °C pupated but adults did not emerge.These laboratory data were used in a computer program whose output under field temperature regimes was compared with events in the field. The program works in 3 h time-steps. Rate of development varies with temperature and utilizes a modification of the algorithm of Stinner et al. (1975); the modification removes time as the independent variable in the development equation. Mortality rates are constant at 1% every 3 h for larvae and 2% for pupae. The program’s predictions for graduation from one stage to the next in the field population were all within about 13 h of the observed times and at the start of the pupal stage after 400 h, the output was running 13 h slow. The program appears to run slow at median temperatures below 10 °C and fast at median temperatures above 14°C. Events in the laboratory rearings are offered as possible explanations for these discrepancies. Predicted population size was close to that observed until the late 4th stage larva, from which point it deviated markedly. Pupal mortality in the field was much higher than in the laboratory.

1976 ◽  
Vol 54 (12) ◽  
pp. 2174-2184 ◽  
Author(s):  
Donald James McQueen

A simulation model for a Porcellio spinicornis Say population was constructed using laboratory data for rates of growth, reproduction, and survival and using winter survival rates observed in the field. The simulated output was compared with field data collected from 1971 to 1973. The expected and observed weight distributions and reproductive periodicities showed good agreement. The expected and observed patterns of numerical change also agreed for all life-history stages, except 18-month-old individuals, which disappeared from the field counts more quickly than expected. Sensitivity analysis showed that the time at which reproduction began each year was not as critical to population growth as were the effects of minor shifts in temperature on individual growth and survival rates. Furthermore, individual growth rate emerged as the factor having the greatest effect on patterns of population growth. Since the laboratory data on growth was reasonably accurate it is probable that the simulation model adequately describes the processes that determine the changes observed in the field population monitored during this study. All of the evidence indicated that during the period of study the population did not increase or decrease and that temperature conditions modifying demographic rates could have accounted for this observation.


2019 ◽  
Vol 11 (4) ◽  
pp. 311-321 ◽  
Author(s):  
Restiana Wisnu Ariyati ◽  
Sri Rejeki ◽  
Lestari L. Widowati ◽  
Tita Elfitasari ◽  
Roel H. Bosma

Abstract The sustainability of prawn farming in brackish water ponds is controversial because of low yields and a history of mangrove clearing. Low yields are due largely to insufficient preparation of pond bottoms. Mangrove trees are often planted on pond bunds as window dressing. This study examines the effect of three types of liquid compost from vegetable, fruit, and both vegetable and fruit in tanks to which whole or chopped Avicennia marina leaves have been added to mimic local pond conditions. In a split-plot design, 28 square tanks were each stocked with one hundred 15-day-old post-larvae tiger prawns (Penaeus monodon). Four tanks were used as controls and 24 were assigned to the treatments, 12 with whole and 12 with chopped leaves. Of the treatment tanks, 4 received liquid compost from vegetable, 4 received fruit, and 4 received mixed vegetable and fruit. Shrimp were weighed at the start, halfway point, and the end of the 50-day trial, and fed at 5% of the estimated total weight; survival was counted at the end. The survival rates of treatments and controls (65–76%) were not significantly different. Shrimp in water with vegetable compost grew significantly faster (2.7% day−1) than in both treatments with fruit (2.5% day−1), while all treatments were associated with significantly faster growth than were the controls (2.0% day−1). The lower growth rate of shrimp fed fruit compost may have been due to dinoflagellates, which are known to negatively affect shrimp. Shrimp in tanks with chopped mangrove leaves grew slightly better than shrimp in tanks with whole mangrove leaves.


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1078D-1079
Author(s):  
Pranitha Patil ◽  
Sung Park

Heavy metal contamination in the ground and its effects on human health has been a major concern. The objective of this experiment is to determine how cadmium affects transgenic and nontransgenic (control) petunia plants. Initially, the petunia seed germination medium (SGM) was prepared, and petunia seeds were sterilized and cultured on the SGM medium. During the actual experiment, using 8-day-old germinated petunia, the SGM-Cd media containing four different concentrations (0, 50, 100, and 200 μM) of CdCl2 were prepared. Plant growth and survival rates in four concentrations of SGM-Cd media were recorded. Over 20 days of observations, the plants showed two distinct differences: color and growth. For the first few days, all of the plants grew very slowly, but the plants showed marked differences in growth and color at later days. On the final day, 22 Jan., the control plants on 0 μM of CdCl2 grew 4.2 cm, while the transgenic plant grew 2.4 cm and showed a dark shade of green color. The control plants on 50 μM grew 1.38 cm, while the transgenic plants grew 2.2 cm. The control plants on 100 μM grew 1.14 cm, while the transgenic plants grew a total of 1.7 cm. Both control and transgenic plants on 200 μM had similar growth of 0.94 cm and showed very light shade of green color. The hypothesis in this experiment was confirmed because CdCl2 impacted the growth of the control and transgenic plants by stunting the growth of the plant and changing its color. It is also demonstrated here that transgenic plants containing the heavy metal transport (HMT) gene can grow better than control because of the specific HMT gene that allowed the plant to uptake more CdCl2 into the central vacuole.


2017 ◽  
Vol 42 (2) ◽  
pp. 99 ◽  
Author(s):  
B. Bakrie ◽  
Y. Sastro ◽  
N. R. Sudolar

This research aimed at investigating the effect using molasses and cornmeal as additives with Lactobacillus sp. and Streptomyces sp. as inoculums during fermentation on the quality of silage flour made from dead chickens. The study was conducted using a completely randomized factorial design, consisting of 2 factors with 5 replications. The materials used were the newly dead chickens which were chopped and mixed thoroughly with all ingredients; then transferred into a 5 liters plastic box for fermentation. Observations were made after 3 weeks fermentation, including: a) physical characteristics, b) microbial contents, and c) nutritional contents. The data were calculated using variance analysis utilizing computer program of SPSS version 21.0. It was found that based on the protein contents the Lactobacillus sp. (19.0%) was better than the Streptomyces sp. (17.8%) if combined with molasses and corn meal as the accelerators. However, the fat contents produced were relatively similar for both of the inoculums (mean of 37.8%). It can be concluded that in order to obtain a best fermented product in terms of the protein and fat content, the dead chicken should be fermented using molasses and cornmeal as the accelerator and Lactobacillus sp. as the inoculum.


Parasitology ◽  
1946 ◽  
Vol 37 (3-4) ◽  
pp. 192-201 ◽  
Author(s):  
J. F. A. Sprent

A description is given of the processes of copulation, formation of the egg and spermatozoon, cleavage, embryogeny and hatching in B. phlebotomum. These processes were found to be essentially similar to those in other strongyle nematodes.The anatomy of the first three larval stages is described and the observations of Conradi & Barnette (1908) and Schwartz (1924) were largely confirmed.Penetration of the skin of calves by the infective larva was observed histologically. The larvae were found to have reached the dermis within 30 min. and to have penetrated the cutaneous blood vessels within 60 min. of application to the skin. The larvae were found in the lung where the third ecdysis was in progress 10 days after penetration of the skin. A description is given of the growth of the third-stage larva in the lung, the changes which take place during the third ecdysis, and the anatomy of the fourth-stage larva.The fourth-stage larvae exsheath in the lungs and travel to the intestine. After a period of growth in which sexual differentiation takes place, the fourth ecdysis occurs and the adult parasite emerges. The time required for the attainment of maturity was found to be somewhere between 30 and 56 days after penetration of the skin.This paper was written at the Ministry of Agriculture and Fisheries Veterinary Laboratories, Wey-bridge, and the writer would like to express his gratitude to the Director, Prof. T. Dalling, also to Dr W. R. Wooldridge, chairman of the Council of the Veterinary Educational Trust for their help and encouragement. The writer's thanks are also due to Dr H. A. Baylis, Prof. R. T. Leiper and Dr E. L. Taylor for their advice and help on technical points, and to Mr R. A. O. Shonekan, African laboratory assistant, for his able co-operation.


Parasitology ◽  
1943 ◽  
Vol 35 (1-2) ◽  
pp. 27-36 ◽  
Author(s):  
D. Keilin ◽  
P. Tate

The larval stages of the celery fly, Acidia heraclei, have been described, and it is shown that this larva agrees with other biontophagous dipterous larvae in having the pharynx devoid of ventral ridges. The transparency of the larvae permits the internal anatomy to be seen clearly in the living larva, and by this means the structure of the perispiracular glands is clearly revealed.The braconid Adelura apii occurs as a parasite of Acidia heraclei larvae, and its first. stage larva is described in detail. This larva is densely hairy, has a long, curved, hairy, tail-like appendage and, by the more rapid growth of the ventral surface, it develops a dorsal curvature which obscures the true orientation so that the true dorsal surface appears externally to be ventral. In these respects the first stage larva of Adelura apii resembles that of A. gahani described by de la Baume-Pluvinel. The later larval stages of A. apii, of which there are at least two, are naked, lack the tail-like appendage and do not differ from the normal type of parasitic hymenopterous larvae.A yeast-like fungus occurs as a parasite in the blood of Acidia heraclei larvae. It is always found associated with existing or abortive infection of the larvae with Adelura apii. Dense mycelial masses sometimes occur in the gut of A. apii pupae and are probably derived from the yeast cells parasitic in the host larvae. It is suggested that this is a unique case of a fungus parasitic in a host larva (Acidia heraclei) undergoing part of its development in a parasitic braconid (Adelura apii), adult females of which transmit the fungus to the host larva during oviposition.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Mikhail Kosiborod ◽  
Silvio Inzucchi ◽  
Harlan M Krumholz ◽  
Lan Xiao ◽  
Phillip G Jones ◽  
...  

Background: Elevated blood glucose (BG) on admission is associated with higher mortality risk in patients (pts) hospitalized with AMI. However, the prognostic value of average BG, which reflects overall glycemic exposure much better than admission BG, is unknown. Furthermore, the nature of the relationship between average BG and mortality has not been determined. Methods: We evaluated a cohort of 16,871 AMI pts hospitalized from January 2000-December 2005, using Cerner Corporation’s Health Facts® database from 40 hospitals, which contains demographics, clinical and comprehensive laboratory data. Logistic regression models evaluated the nature of the relationship between mean BG during the entire AMI hospitalization and in-hospital mortality, after adjusting for multiple patient factors and confounders. Similar analyses were performed in subgroups of pts with and without diabetes (DM). Results: A J-shaped relationship was observed between mean BG and in-hospital mortality, which persisted after multivariable adjustment (Figure ). Mortality increased with each 10 mg/dL incremental rise in mean BG over >120 mg/dL, and with incremental decline in mean BG <80 mg/dL. The slope of these relationships was much steeper in pts without DM. Conclusions: Average BG during the entire AMI hospitalization is a powerful independent predictor of in-hospital mortality. Both persistent hyper- and hypoglycemia are associated with adverse prognosis. Whether strategies directed at optimizing BG control will improve survival remains to be established. Association Between Mean BG and In-Hospital Mortality After Multivariable Adjustment (Reference: Mean BG 100 to <110)


2016 ◽  
Vol 5 (4) ◽  
pp. 13 ◽  
Author(s):  
Daud Kassam ◽  
Marcus Sangazi

<p>Most fish farmers in Malawi culture unimproved fish strains whose growth is slow and mature while still small. Four strains of <em>Oreochromis</em>, namely; selectively-bred/improved <em>O. shiranus</em> (F<sub>8</sub>), two reciprocal F<sub>1</sub> <em>Oreochromis</em> hybrids, and <em>O. karongae</em> as a control (mean weight 2.5 ± 0.7 g) were stocked at a density of 5fish/m<sup>2 </sup>in 9m<sup>2 </sup>hapas replicated three times, and cultured for 90 days at Bunda Fish Farm. Fish were fed twice a day with feed formulated using maize bran and soybean containing 30% crude protein throughout the experimental period. The final mean weights were significantly different (p&lt;0.05) across the treatments whereby; hybrid <em>O. shiranus</em> (male) X <em>O. karongae</em> (female) was 12.09g, hybrid <em>O. shiranus</em> (female) X <em>O. karongae</em> (male) was 9.72g, improved <em>O. shiranus</em> (F<sub>8</sub>) registered 9.23g, and <em>O. karongae</em> was the least with 9.00g. Apparent food conversion ratio was also statistically different (p&lt;0.05) across the treatments whereby; <em>O. karongae</em> was 3.63, hybrid <em>O. shiranus</em> (female) X <em>O. karongae</em> (male) was 3.25, improved <em>O. shiranus</em> (F<sub>8</sub>) was 3.16 and hybrid <em>O. shiranus</em> (male) X <em>O. karongae</em> (female) was lowest with 2.26. There were no significant differences on the water quality parameters across the treatments throughout the experimental period and were within the required ranges for growth and survival of tilapias fish species. The results suggest that <em>Oreochromis</em> hybrids may be suitable candidates for aquaculture in terms of production as they performed better than the improved <em>O. shiranus</em> and the control <em>O. karongae</em>.</p>


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Guangchuan Wang ◽  
Dongxiao Meng ◽  
Guangjun Huang ◽  
Qingshan Pei ◽  
Lianhui Zhao ◽  
...  

Aims. To evaluate the safety and effectiveness of percutaneous transhepatic antegrade embolization (PTAE) with 2-octyl cyanoacrylate assisted with balloon occlusion of the left renal vein or gastrorenal shunts (GRSs) for the treatment of isolated gastric varices (IGVs) with large GRSs. Methods. Thirty patients with IGVs associated with large GRSs who had underwent PTAE assisted with a balloon to block the opening of the GRS in the left renal vein were retrospectively evaluated and followed up. Clinical and laboratory data were collected to evaluate the technical success of the procedure, complications, changes in the liver function using Child-Pugh scores, worsening of the esophageal varices, the rebleeding rate, and survival. Laboratory data obtained before and after PTAE were compared (paired-sample t-test). Results. PTAE was technically successful in all 30 patients. No serious complications were observed except for one nonsymptomatic pulmonary embolism. During a mean follow-up of 30 months, rebleeding was observed in 4/30 (13.3%) patients, worsening of esophageal varices was observed in 4/30 (13.3%) patients, and newly developed or aggravated ascites were observed on CT in 3/30 (10%) patients. Significant improvement was observed in Child-Pugh scores (p=0.009) and the international normalized ratio (INR) (p=0.004) at 3 months after PTAE. The cumulative survival rates at 1, 2, 3, and 5 years were 96.3%, 96.3%, 79.9%, and 79.9%, respectively. Conclusion. Balloon-assisted PTAE with 2-octyl cyanoacrylate is technically feasible, safe, and effective for the treatment of IGV associated with a large GRS.


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