INCREASE IN THE LEVEL OF RETINAL MELATONIN AND PERSISTENCE OF ITS DIURNAL RHYTHM IN RATS AFTER PINEALECTOMY

1981 ◽  
Vol 91 (3) ◽  
pp. 477-481 ◽  
Author(s):  
H. S. YU ◽  
S. F. PANG ◽  
P. L. TANG
Keyword(s):  
Diurnal Rhythm ◽  
Feedback System ◽  
Male Rats ◽  
Long Term Effects ◽  
Term Experiment ◽  
Long Term Experiment ◽  
Short And Long Term ◽  
Short Term Experiment ◽  
Compensatory Effect

To study the short- and long-term effects of pinealectomy on the level of retinal melatonin, male rats adapted to a photoperiod of 12 h light: 12 h darkness (with lights on at 06.00 h) were pinealectomized. In the short-term experiment, the rats were decapitated 1 week after pinealectomy. In the long-term experiment, 1 month was allowed for recovery. Melatonin was extracted from retinae and quantified by radioimmunoassay. A diurnal rhythm of retinal melatonin was found to persist after pinealectomy in both experiments. An increase in retinal melatonin was demonstrated 1 month after pinealectomy, indicating a compensatory effect on melatonin in the retinae of pinealectomized rats. Thus, biosynthesis of melatonin in the retina may be modulated through a negative feedback system.

EFFECT OF HEAVY MUSCULAR WORK ON THE MORPHOLOGY AND HISTOCHEMISTRY OF THE RAT TESTIS

1963 ◽  
Vol 43 (2) ◽  
pp. 311-320 ◽  
Author(s):  
M. Härkönen ◽  
E. Kontinen ◽  
M. Kormano ◽  
M. Niemi
Keyword(s):  
Leydig Cells ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
List Type ◽  
Muscular Work ◽  
Term Experiment ◽  
Long Term Experiment ◽  
Short And Long Term ◽  
Short Term Experiment

ABSTRACT The effect of short- and long-term muscular work on the Leydig cells of the rat was studied. The rats were allowed to run in a rotating wire cylinder for various periods. The amount of stress was evaluated by the involution of the thymus, ulceration of the gastric mucosa, enlargement of adrenal glands and their lipid and catecholamine contents. After a short-term experiment, periods of 16 + 10 hours' running with rest for 10 hours in between, accessory genital organs were slightly involuted 4 to 8 days following the stress. The testes were histologically and histochemically intact. Similar results were obtained after a long-term experiment, comprising continuous daily running for 10 hours over a period of 12 days. In a progressive long-term experiment, viz. daily running until exhaustion for 14 days, temporary degeneration of the Leydig cells occurred: the percentage of interstitial tissue and the size of the nuclei of the Leydig cells diminished and the number of degenerating Leydig cells significantly increased. Oxidative enzyme activity was markedly suppressed. DPN-diaphorase and β-hydroxybutyric dehydrogenase activity were very markedly decreased. The involution of the accessory genital organs was more pronounced than in the two former experiments. All these phenomena reverted to normal within ten days. In every experiment the seminiferous tubules remained histologically normal.

scholarly journals A Case Study on User Evaluation of Scientific Publication Summarization by Japanese Students

2021 ◽  
Vol 11 (14) ◽  
pp. 6287
Author(s):  
Shintaro Yamamoto ◽  
Ryota Suzuki ◽  
Tsukasa Fukusato ◽  
Hirokatsu Kataoka ◽  
Shigeo Morishima
Keyword(s):  
Scientific Publication ◽  
Automatic Summarization ◽  
Scientific Publications ◽  
Japanese University ◽  
Term Experiment ◽  
Long Term Experiment ◽  
Short And Long Term ◽  
Short Term Experiment

Summaries of scientific publications enable readers to gain an overview of a large number of studies, but users’ preferences have not yet been explored. In this paper, we conduct two user studies (i.e., short- and long-term studies) where Japanese university students read summaries of English research articles that were either manually written or automatically generated using text summarization and/or machine translation. In the short-term experiment, subjects compared and evaluated the two types of summaries of the same article. We analyze the characteristics in the generated summaries that readers regard as important, such as content richness and simplicity. The experimental results show that subjects are mainly judged based on four criteria, including content richness, simplicity, fluency, and format. In the long-term experiment, subjects read 50 summaries and answered whether they would like to read the original papers after reading the summaries. We discuss the characteristics in the summaries that readers tend to use to determine whether to read the papers, such as topic, methods, and results. The comments from subjects indicate that specific components of scientific publications, including research topics and methods, are important to judge whether to read or not. Our study provides insights to enhance the effectiveness of automatic summarization of scientific publications.

scholarly journals Short-and long-term effects of proallatotoxin (Ethoxyprecocene II) on Rhodnius prolixus females

1987 ◽  
Vol 82 (2) ◽  
pp. 247-251 ◽  
Author(s):  
Patricia de Azambuja ◽  
Eloi S. Garcia
Keyword(s):  
Egg Production ◽  
Rhodnius Prolixus ◽  
Corpus Allatum ◽  
Long Term Effects ◽  
Oocyte Growth ◽  
Egg Maturation ◽  
Term Experiment ◽  
Long Term Experiment ◽  
Short Term Experiment

Oogenesis and oviposition can be inhibited in female of Rhodnius prolixus by means of short-term experiment (first reproductive cycle) of a single dose of ethoxyprecocene II given by ingestion. The inhibition is dose-dependent as measured by oocyte growth, egg maturation and egg deposition. In a long-term experiment (second and third reproductive cycles) egg production and oogenesis can be partially or totally re-established by subsequent blood meals without ethoxyprecocene II. These findings suggest that in female R. prolixus, damage caused to corpus allatum by ethoxyprecocene II, in certain cases, is not irreversible.

scholarly journals Alley Cropping Increases Land Use Efficiency and Economic Profitability Across the Combination Cultivation Period

Agronomy ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 34 ◽  
Author(s):  
Huasen Xu ◽  
Huaxing Bi ◽  
Lubo Gao ◽  
Lei Yun
Keyword(s):  
Land Use ◽  
Crop Yields ◽  
Alley Cropping ◽  
Cropping Systems ◽  
Land Use Efficiency ◽  
Term Experiment ◽  
Long Term Experiment ◽  
Use Efficiency ◽  
Short Term Experiment

Alley cropping allows the famer to effectively use available resources and yield more benefits. Choosing suitable associated crop and mitigating the competition between trees and crops are crucial for designing the alley cropping systems. We conducted a long-term experiment, including apple (Malus pumila)/peanut (Arachis hypogaea), apple/millet (Setaria italica) and apple/maize (Zea mays) alley cropping systems with conventional intercropping distance, and corresponding monocultures (Exp.1), and a short-term experiment with improved intercropping distance in the same three combinations (Exp.2) in the Loess Plateau, China. The results showed crop yields in three alley cropping systems were lower than the corresponding monocultures. Apple yields were significantly constrained by millet and maize in the alley cropping systems, but not sensitive to the presence of peanut. Land equivalent ratios (LERs) ranged from 0.44 to 0.89 before the tree bore fruit. The LERs were greater than 1.0 after the tree bore fruit, and the apple trees made a decisive contribution to the land use advantage. Net present values of three alley cropping systems were on average 60.1% higher than the corresponding monocultures across the alley cropping period. The maximum annual present value in the first–fifth, sixth and seventh–ninth years after the alley cropping establishment was observed in the apple/maize, apple/millet and apple/peanut system, respectively. These results highlight that choosing the optimal alley cropping management and suitable associated crops at different years after establishment may allow farmers to increase the land use efficiency and economic profitability.

scholarly journals Long-term resource addition to a detrital food web yields a pattern of responses more complex than pervasive bottom-up control

2017 ◽  
Author(s):  
Kendra L. Lawrence ◽  
David H Wise
Keyword(s):  
Field Experiments ◽  
Abiotic Factors ◽  
Short Term ◽  
Bottom Up ◽  
Term Experiment ◽  
Two Factors ◽  
Long Term Experiment ◽  
Short Term Experiment ◽  
Univariate Analyses

Background. Theory predicts strong bottom-up control in detritus-based food webs, yet field experiments with detritus-based terrestrial systems have uncovered contradictory evidence regarding the strength and pervasiveness of bottom-up control processes. Two factors likely leading to contradictory results are experiment duration, which influences exposure to temporal variation in abiotic factors such as rainfall and affects the likelihood of detecting approach to a new equilibrium; and openness of the experimental units to immigration and migration. To investigate the contribution of these two factors, we conducted a long-term experiment with open and fenced plots in the forest that was the site of an earlier, short-term experiment (3.5 months) with open plots (Chen & Wise 1999) that produced evidence of strong bottom-up control for 14 taxonomic groupings of primary consumers of litter and fungi (microbi-detritivores) and their predators. Methods. We added artificial high-quality detritus to ten 2 x 2-m forest-floor plots at bi-weekly intervals from April through September in three consecutive years (Supplemented treatment). Ten comparable Ambient plots were controls. Half of the Supplemented and Ambient plots were enclosed by metal fencing. Results. Arthropod community structure (based upon 18 response variables) diverged over time between Supplemented and Ambient treatments, with no effect of Fencing on the multivariate response pattern. Fencing possibly influenced only ca. 20% of the subsequent univariate analyses. Multi- and univariate analyses revealed bottom-up control by fall of Year 1 of some, but not all, microbi-detritivores and predators. During the following two years the pattern of responses became more complex than that observed by Chen & Wise (1999). Some taxa showed consistent bottom-up control whereas many did not. Variation across years could not be explained completely by differences in rainfall because some taxa exhibited negative, not positive, responses to detrital supplementation. Discussion. Our 3-yr experiment did not confirm the conclusion of strong, pervasive bottom-up control of microbi-detritivores and predators reported by Chen and Wise (1999). Our longer-term experiment revealed a more complex pattern of responses, a pattern much closer to the range of outcomes reported in the literature for many short-term experiments. Much of the variation in responses across studies likely reflects variation in factors such as rainfall and the quality of added detritus. Nevertheless, it is also possible that long-term resource enhancement can drive a community towards a new equilibrium state that differs from what would have been predicted from the initial short-term responses exhibited by primary and secondary consumers.

Bone and mineral metabolism in aged male rats: short and long term effects of androgen deficiency.

Endocrinology ◽  
1992 ◽  
Vol 130 (5) ◽  
pp. 2906-2916 ◽  
Author(s):  
D Vanderschueren ◽  
E Van Herck ◽  
A M Suiker ◽  
W J Visser ◽  
L P Schot ◽  
...  
Keyword(s):  
Mineral Metabolism ◽  
Male Rats ◽  
Androgen Deficiency ◽  
Long Term Effects ◽  
Short And Long Term

scholarly journals Different Effects of Soy and Whey on Linear Bone Growth and Growth Pattern in Young Male Sprague-Dawley Rats

2021 ◽  
Vol 8 ◽  
Author(s):  
Meytal Bar-Maisels ◽  
Chen Menahem ◽  
Yankel Gabet ◽  
Sahar Hiram-Bab ◽  
Moshe Phillip ◽  
...  
Keyword(s):  
Food Consumption ◽  
Bone Quality ◽  
Linear Growth ◽  
Young Male ◽  
Male Rats ◽  
Term Experiment ◽  
Igf I ◽  
Long Term Experiment ◽  
Ad Libitum

The aim of this investigation was to determine the better protein for supporting optimal linear growth, as the exact composition and benefits of specific dietary proteins in supporting linear growth is unknown. In the current study, we compared the effect of soy and whey proteins, both proteins contain all essential amino acids and are considered the best proteins in their categories. Young male rats were subjected to multiple feeding protocols using iso-energetic diets containing soy or whey as the sole protein source. The rats were allowed to eat ad libitum for 11, 24, or 74 days in the first set of experiments, and the soy group was pair-fed to the whey group in the second set. The differences in weight gain, food consumption, and humeri length of the soy group that were greater at the beginning of the ad libitum experiments lessened over time. Pair-fed experiments revealed that the increased weight and humeri length resulted from the differences in food consumption. However, other parameters were protein specific. Bone quality, which was better in the soy group at 24 days, was matched by the whey group and even surpassed that of the soy group in the long-term experiment, with a significantly greater bone mineral density, cortical thickness, and growth plate. Although in the short term the levels of insulin like growth factor (IGF)-I were similar between the groups, IGF-I increased with age in the whey group, and the levels at the long-term experiment were significantly higher compared to the soy group. Furthermore, using the pair fed setup made it clear that when the difference in food consumption were no longer playing part, whey was more efficient in increasing IGF-I. There were no indications of metabolic sequelae. Although the use of soy is gaining in popularity as a sustainable protein, our findings indicate a better effect of whey on linear growth by leading to slower growth with better-organized epiphyseal growth plates and bone quality.

Long / Short Term Experimental Study on Chloride Penetration in Cracked Concrete

2009 ◽  
Vol 417-418 ◽  
pp. 765-768 ◽  
Author(s):  
In Seok Yoon ◽  
Erik Schlangen
Keyword(s):  
Chloride Penetration ◽  
Crack Healing ◽  
Short Term ◽  
Cracked Concrete ◽  
Term Experiment ◽  
Long Term Experiment ◽  
Set Up ◽  
Short Term Experiment ◽  
Penetration Behaviour

This study is focused on examining the effect of cracks on chloride penetration into concrete. In order to get reliable results, short-term and long term experiments were set up and chloride penetration behaviour through cracks was examined. It was noticed that chloride penetration through cracks tends to decrease with time. One of the explanations is crack-healing. Especially, this trend was obvious in concrete samples with larger crack width. However, measuring the border between chloride contaminated zone and healthy zone was clear in concrete of short-term experiment, while it was ambiguous in long term experiment.

Mechanisms of potassium release from calcareous soils to different salt, organic acid and inorganic acid solutions

Soil Research ◽  
2019 ◽  
Vol 57 (3) ◽  
pp. 301 ◽  
Author(s):  
M. Najafi-Ghiri ◽  
M. Niazi ◽  
M. Khodabakhshi ◽  
H. R. Boostani ◽  
H. R. Owliaie
Keyword(s):  
Citric Acid ◽  
Organic Acids ◽  
Calcareous Soils ◽  
Acid Solutions ◽  
Short Term ◽  
Term Experiment ◽  
Short And Long Term ◽  
Fixation Capacity ◽  
Short Term Experiment

Mechanisms of potassium (K) release and fixation in calcareous soils may differ from non-calcareous soils. In the current investigation, four soils with different properties were extracted three and 10 times (45 and 150min, defined as short- and long-term respectively) with 0.025molL−1 CaCl2, HCl and oxalic and citric acid solutions and the contents of calcium (Ca), magnesium (Mg), aluminium (Al) and K in the extracts were determined. Immediately after K extraction, 500mg kg–1 of K (as KCl) was added to the remaining soils and shaken for 24h and K-fixation capacity was determined. No significant difference was observed between CaCl2 and HCl solutions in K extraction from soils in the short- and long-term experiments; the concentrations of Ca, Mg and Al in the extractants showed that HCl was not able to dissolve soil minerals and the soils released K via exchange reaction of Ca (originated from CaCO3 dissolution by HCl) with interlayer K. The organic acids had similar behaviour to each other in the short-term experiment; however, partial dissolution of minerals by citric acid was observed. Oxalic acid extracted less K than other solutions in the short-term experiment due to precipitation of soluble Ca as oxalate salt and thereby less exchange of soluble Ca with non-exchangeable K. Oxalic and citric acids dissolved K-bearing minerals and released K in the long-term experiment, but oxalic acid was more effective. The K-fixation capacity of soils was lower when treated with organic acids than with CaCl2 and HCl, possibly due to the dissolution of K-fixing minerals like smectite and illite by oxalate and citrate. Long-term treatment of soils with different solutions decreased K-fixation capacity of soils due to dissolution of K-fixing minerals or flocculation of minerals by Ca and slower K diffusion to the interlayer. With respect to the highly calcareous nature of the studied soils, the soluble cations in calcareous soils (predominantly Ca and Mg) may have been exchanged with non-exchangeable K of clay minerals and buffered soluble K as well as organic acids produced by plant roots and microorganisms.

Differential effects of the administration of human chorionic gonadotropin to postnatal rats

1994 ◽  
Vol 142 (3) ◽  
pp. 527-534 ◽  
Author(s):  
F Gaytan ◽  
L Pinilla ◽  
J L Romero ◽  
E Aguilar
Keyword(s):  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Leydig Cells ◽  
Reproductive Function ◽  
Male Rats ◽  
Testicular Development ◽  
Long Term Effects ◽  
Adult Type ◽  
Short And Long Term

Abstract Neonatal and prepubertal male rats were treated with human chorionic gonadotropin (hCG, 5 IU/g body weight per day) on days 2–4 or 20–22. Depending on the date of treatment, different groups of rats were sacrificed at 5, 23, 30 and 100 days of age, in order to study the short-and long-term effects of the treatment with hCG on the development of the testes and sex accessory organs. Rats treated with hCG on days 2–4 showed increased number and size of foetal Leydig cells at 5 days of age. However, long-term effects include decreased numbers of adult-type Leydig cells, decreased weight of the testes and sex accessory organs, decreased basal and hCG-stimulated testosterone secretion, and delayed balano-preputial separation. In contrast, animals treated with hCG on days 20–22 showed similar short- and long-term effects, consisting of increased number of adult-type Leydig cells and macrophages, increased weight of the testes and sex accessory organs and advanced balano-preputial separation. In adulthood, both groups showed normal reproductive function. These results seem to indicate that the effects of hCG treatment in prepubertal rats are dependent on the type of Leydig cell stimulated, and suggest that foetal Leydig cells play a regulatory role in the early postnatal testicular development. Journal of Endocrinology (1994) 142, 527–534

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