scholarly journals Diet influence on egg production of the copepod Acartia tonsa (Dana, 1896)

2010 ◽  
Vol 82 (2) ◽  
pp. 333-339 ◽  
Author(s):  
Priscila F. Teixeira ◽  
Sonia M. Kaminski ◽  
Tatiana R. Avila ◽  
Alessandro P. Cardozo ◽  
José G.F. Bersano ◽  
...  
Keyword(s):  
Egg Production ◽  
Isochrysis Galbana ◽  
Threshold Value ◽  
Acartia Tonsa ◽  
Thalassiosira Weissflogii ◽  
Chaetoceros Muelleri ◽  
Experimental Conditions ◽  
Male And Female ◽  
Experimental Medium ◽  
Controlled Conditions

Egg production in the copepod Acartia tonsa was evaluated using different densities of the microalgae Thalassiosira weissflogii, Chaetoceros muelleri and Isochrysis galbana. Male and female were kept under controlled conditions (salinity 30, 20°C, photoperiod 12L:12D), acclimated to the experimental conditions and left over a period of 24 h to allow copulation. Algal densities tested were equivalent in biovolume and corresponded to 0, 2.5, 5, 10, 20, 40 and 60.10³ cells.mL-1 of T weissflogii. Ten acclimated female were separated, transferred to glass bottles and exposed for further 24 h to the corresponding experimental medium. After this period, the eggs were fixed and counted. Copepod egg production reached a threshold value when T weissflogii, C. muelleri and I. galbana were supplied at 10.10³, 140.10³ and 640.10³ cells.mL-1, respectively. Mean egg production corresponded to 28.0 ± 0.5, 20.1 ± 1.0 and 22.0 ± 3.5 eggs.female-1 .day-1, respectively. Copepods fed T weissflogii showed the highest mean egg production while those fed I. galbana reached a maximum egg production when the algae were supplied at a density two- to fourfold higher, considering the biovolume of T weissflogii and C. muelleri. These differences are explained considering the different sizes of the microalgae used to feed the copepods.

Feeding ecology of Apocyclops procerus (Copepoda, Cyclopoida) under experimental conditions

Crustaceana ◽  
2015 ◽  
Vol 88 (3) ◽  
pp. 283-297
Author(s):  
M. Guenther ◽  
R. Durst ◽  
W. S. Felismino ◽  
V. T. Pessoa ◽  
S. Neumann-Leitão
Keyword(s):  
Food Supply ◽  
Egg Production ◽  
Feeding Habits ◽  
Adult Life ◽  
Isochrysis Galbana ◽  
First Record ◽  
Chaetoceros Muelleri ◽  
Experimental Conditions ◽  
Adult Life Span ◽  
Copepoda Cyclopoida

Copepods are key links between primary producers and higher pelagics. We investigated, for the first time, under laboratory conditions, some aspects of the reproductive behaviour and feeding preferences of Apocyclops procerus (Copepoda: Cyclopoida) under different conditions of salinity and food supply. This is also its first record for Pernambuco (NE Brazil). The females carry their eggs until their eclosion and present several cycles of egg production without being further fecundated. Egg production and adult life span were not affected by differences in salinity or food supply. Offspring predation was also observed. From the three microalgae species offered to A. procerus individuals, Thalassiosira weissflogii, Chaetoceros muelleri (Ochrophyta) and Isochrysis galbana (Haptophyta), the small round-shaped I. galbana was preferred over the large and spiny diatoms, in spite of its lower nutritional value. The high salinity tolerance and apparently omnivorous feeding habits of A. procerus may enable it to predominate in estuarine waters.

THE PITUITARY AND ADRENAL RESPONSES TO ADMINISTRATION OF OESTRIOL IN GONADECTOMIZED RATS

1961 ◽  
Vol 38 (1) ◽  
pp. 50-58 ◽  
Author(s):  
N. E. Borglin ◽  
L. Bjersing
Keyword(s):  
Pituitary Gland ◽  
Adrenal Cortex ◽  
Clinical Experience ◽  
Uterine Cervix ◽  
Morphological Changes ◽  
Physiological Significance ◽  
Female Rats ◽  
Experimental Conditions ◽  
Male And Female ◽  
Male And Female Rats

ABSTRACT Oestriol (oestra-1,3,5(10)-triene-3,16α,17β-triol) is a weakly oestrogenic substance which, however, in contrast to what was formerly believed, is of physiological significance. Its effect is localized largely to the uterine cervix and vagina. Clinical experience argues both for and against an effect on the pituitary gland. This investigation is concerned with the morphological changes in the pituitary gland and adrenal cortex of gonadectomized male and female rats after the injection of oestriol. It was found that oestriol has the same type of action on these glands as other oestrogens, but under the experimental conditions used, this effect proved much weaker than that produced by oestradiol (oestra-1,3,5(10)-triene-3,17β-diol).

scholarly journals Development of a Protocol and a Diagrammatic Scale for Quantification of Bacterial Leaf Streak Disease on Young Plants of Maize

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 2921-2927
Author(s):  
Renata Rodrigues Robaina ◽  
Talita Vigo Longhi ◽  
Douglas Mariani Zeffa ◽  
Leandro Simões Azeredo Gonçalves ◽  
Rui Pereira Leite
Keyword(s):  
Disease Incidence ◽  
The United States ◽  
Bacterial Suspension ◽  
Bacterial Leaf Streak ◽  
Experimental Conditions ◽  
Maize Production ◽  
Maize Hybrids ◽  
Controlled Conditions ◽  
Maize Plants ◽  
Diagrammatic Scale

Bacterial leaf streak (BLS), caused Xanthomonas vasicola pv. vasculorum (Xvv), has become a major concern for maize production, mainly in the United States and South America. Therefore, this study aimed to establish a protocol for Xvv inoculation in young maize plants under controlled conditions and to develop and validate a diagrammatic scale for evaluation of maize hybrids in regard to BLS resistance. The study was carried out in three steps: the establishment of a protocol for inoculation of Xvv in young maize plants under controlled conditions; the development and validation of a diagrammatic scale for BLS severity evaluation; and the screening for BLS resistance of 45 hybrids using the proposed protocol for bacterial inoculation and the diagrammatic scale developed in this study. Besides reproducing a more natural Xvv infection, the bacterial suspension spraying without injury inoculation method induced higher disease incidence and severity, as well as reproducibility of results under the experimental conditions established in this study. The proposed diagrammatic scale allowed evaluating BLS severity with up to 97.49% of the leaf area affected by the disease. Further, the use of the diagrammatic scale resulted in an increase of accuracy from 0.909 up to 0.992. The reaction of 45 maize hybrids to BLS allowed establishing six major groups of susceptibility to the disease. The most resistant maize hybrids to BLS formed a group of 13 hybrids, with disease severity below 5%.

Effects of adult stocking density on egg production and viability in cultures of the calanoid copepod Acartia tonsa (Dana)

2007 ◽  
Vol 38 (7) ◽  
pp. 764-772 ◽  
Author(s):  
Per M Jepsen ◽  
Nikolaj Andersen ◽  
Thue Holm ◽  
Anders T Jørgensen ◽  
Jonas K Højgaard ◽  
...  
Keyword(s):  
Egg Production ◽  
Calanoid Copepod ◽  
Stocking Density ◽  
Acartia Tonsa

scholarly journals In vitro effects of artesunate on the survival of worm pairs and egg production of Schistosoma mansoni

2009 ◽  
Vol 83 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Y. Mitsui ◽  
M. Miura ◽  
Y. Aoki
Keyword(s):  
Schistosoma Mansoni ◽  
Adult Worm ◽  
Survival Time ◽  
Egg Production ◽  
Inhibitory Effect ◽  
Male And Female ◽  
Paired Male ◽  
In Vitro Effects ◽  
Paired Female

AbstractThe effect of artesunate (ART) on the survival time of adult worm pairs of Schistosoma mansoni and on their egg output during in vitro culture was assessed. ART significantly decreased the survival time of both paired male and female worms at concentrations of 5, 10, 20 and 40 mg l− 1 during in vitro cultivation. An inhibitory effect of ART on the daily egg output of paired female worms during in vitro cultivation was also observed.

scholarly journals Effects of Sex and 17 β-Estradiol on Cardiac Fibroblast Morphology and Signaling Activities In Vitro

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2564
Author(s):  
Kelsey Watts ◽  
William J. Richardson
Keyword(s):  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Cellular Level ◽  
Cellular Morphology ◽  
Structural Level ◽  
Experimental Conditions ◽  
Male And Female ◽  
Protein Protein Interaction ◽  
Complex Signaling

Several studies have demonstrated estrogen’s cardioprotective abilities in decreasing the fibrotic response of cardiac fibroblasts (CFs). However, the majority of these studies are not sex-specific, and those at the cellular level utilize tissue culture plastic, a substrate with a much higher stiffness than physiological conditions. Understanding the intrinsic differences between male and female CFs under more physiologically “healthy” conditions will help to elucidate the divergences in their complex signaling networks. We aimed to do this by conducting a sex-disaggregated analysis of changes in cellular morphology and relative levels of profibrotic signaling proteins in CFs cultured on 8 kPa stiffness plates with and without 17 β-estradiol (E2). Cyclic immunofluorescent analysis indicated that there was a negligible change in cellular morphology due to sex and E2 treatment and that the differences between male and female CFs occur at a biochemical rather than structural level. Several proteins corresponding to profibrotic activity had various sex-specific responses with and without E2 treatment. Single-cell correlation analysis exhibited varied protein–protein interaction across experimental conditions. These findings demonstrate the need for further research into the dimorphisms of male and female CFs to develop better tailored sex-informed prevention and treatment interventions of cardiac fibrosis.

scholarly journals Subchronic Toxicity Assessment of Phytolacca americana L. (Phytolaccaceae) in F344 Rats

2020 ◽  
Vol 15 (7) ◽  
pp. 1934578X2094165
Author(s):  
Hyoung-Yun Han ◽  
Kang-Hyun Han ◽  
Jun-Ho Ahn ◽  
Se-Myo Park ◽  
Soojin Kim ◽  
...  
Keyword(s):  
Body Weight ◽  
Adverse Effects ◽  
Clinical Chemistry ◽  
Toxicity Assessment ◽  
Phytolacca Americana ◽  
Subchronic Toxicity ◽  
Experimental Conditions ◽  
Male And Female ◽  
Long Term Treatment ◽  
F344 Rats

Phytolacca americana L. is traditionally used in Korea, Japan, and China as a diuretic, antibacterial, antiviral, anticancer, and anti-inflammatory agent, and also in the treatment of hepatitis B, psoriasis, edema, and rheumatism. In this study, we evaluated the subchronic toxicity of an aqueous extract of P. americana (PAAE) in male and female F344 rats. The rats were orally administered PAAE (0, 500, 1000, and 2000 mg/kg body weight) once daily for 13 weeks. Mortality rate, body weight, food consumption, and organ weights were measured and assessed. Additionally, ophthalmological, hematological, and histopathological parameters were evaluated. Urinalysis and necropsy were also performed. The clinical chemistry values for potassium in the treated female groups (500, 1000, and 2000 mg/kg/ body weight/day) were higher than those in the control. Further, the relative weights of the kidneys in the treated female groups (1000 and 2000 mg/kg/ body weight/day) were higher than those in the control. However, these changes were not consistent in either sex, and no abnormalities were found in the corresponding pathological findings. Thus the results showed no adverse effects in all the parameters assessed. The findings show that after 13 weeks of treatment, the “no-observed-adverse-effect level” of PAAE is 2000 mg/kg body weight in both male and female F344 rats under the experimental conditions applied. Although treatment-related adverse effects were not seen, potassium-level changes in the blood should be examined to establish the safety profile of PAAE after long-term treatment.

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