scholarly journals Dynamics and Spatial Shape of Short-Period Meteoroid Streams

1989 ◽  
Vol 8 ◽  
pp. 287-293 ◽  
Author(s):  
P.B. Babadzhanov ◽  
Yu.V. Obrubov

AbstractAt the early stage of evolution the meteoroid streams may be considered as elliptical rings of relatively small thickness. The influence of planetary perturbations can essentially increase the stream width and its thickness. As a result one stream may produce several couples of meteor showers active in different seasons of the year. 22 short-period meteoroid streams under review may theoretically produce 104 meteor showers. The existence of 67 is confirmed by observations.

2021 ◽  
Vol 22 (11) ◽  
pp. 5851
Author(s):  
Takehito Sugasawa ◽  
Seiko Ono ◽  
Masato Yonamine ◽  
Shin-ichiro Fujita ◽  
Yuki Matsumoto ◽  
...  

The prevalence of nonalcoholic fatty liver disease (NAFLD) has been rapidly increasing worldwide. A choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) has been used to create a mouse model of nonalcoholic steatohepatitis (NASH). There are some reports on the effects on mice of being fed a CDAHFD for long periods of 1 to 3 months. However, the effect of this diet over a short period is unknown. Therefore, we examined the effect of 1-week CDAHFD feeding on the mouse liver. Feeding a CDAHFD diet for only 1-week induced lipid droplet deposition in the liver with increasing activity of liver-derived enzymes in the plasma. On the other hand, it did not induce fibrosis or cirrhosis. Additionally, it was demonstrated that CDAHFD significantly impaired mitochondrial respiration with severe oxidative stress to the liver, which is associated with a decreasing mitochondrial DNA copy number and complex proteins. In the gene expression analysis of the liver, inflammatory and oxidative stress markers were significantly increased by CDAHFD. These results demonstrated that 1 week of feeding CDAHFD to mice induces steatohepatitis with mitochondrial dysfunction and severe oxidative stress, without fibrosis, which can partially mimic the early stage of NASH in humans.


2009 ◽  
Vol 626-627 ◽  
pp. 1-4
Author(s):  
Pai Shan Pa

In the current study, a reclamation module uses micro electroetching as a precision fabrication with a new design of T-form tool to remove the defective Indium-tin-oxide (TCO) nanostructure from the optical PET surfaces of digital paper display is presented in current studies. The adopted precision reclamation process requires only a short period of time to remove the TCO nanostructure easily and cleanly is based on technical and economical considerations and is highly efficient. A large rotational diameter of the cathode accompanied by a small gap width between the cathode and the workpiece corresponds to a higher removal rate for the TCO nanostructure. A small thickness of the electrodes, or a small edge radius of the electrodes takes less time for the same amount of TCO removal. A higher feed rate of the optical PET diaphragm combines with enough electric power to drive fast etching rate. High rotational speed of the T-form tool can improve the effect of dregs discharge and is advantageous to associate with the fast feed rate of the workpiece (optical PET diaphragm).


2020 ◽  
Vol 78 (1) ◽  
Author(s):  
Romain Laurian ◽  
Cécile Jacot-des-Combes ◽  
Fabiola Bastian ◽  
Karine Dementhon ◽  
Pascale Cotton

ABSTRACT During Candida macrophage interactions, phagocytosed yeast cells feed in order to grow, develop hyphae and escape. Through numerous proteomic and transcriptomic studies, two metabolic phases have been described. A shift to a starvation mode is generally identified as early as one-hour post phagocytosis, followed by a glycolytic growth mode after C. albicans escaped from the macrophage. Healthy macrophages contain low amounts of glucose. To determine if this carbon source was sensed and metabolized by the pathogen, we explored the transcription level of a delimited set of key genes expressed in C. albicans cells during phagocytosis by macrophages, at an early stage of the interaction. This analysis was performed using a technical digital droplet PCR approach to quantify reliably the expression of carbon metabolic genes after 30 min of phagocytosis. Our data confirm the technique of digital droplet PCR for the detection of C. albicans transcripts using cells recovered after a short period of phagocytosis. At this stage, carbon metabolism is clearly oriented towards the use of alternative sources. However, the activation of high-affinity glucose transport system suggests that the low amount of glucose initially present in the macrophages is detected by the pathogen.


Solid Earth ◽  
2015 ◽  
Vol 6 (3) ◽  
pp. 823-837 ◽  
Author(s):  
J. Rodrigo Comino ◽  
C. Brings ◽  
T. Lassu ◽  
T. Iserloh ◽  
J. M. Senciales ◽  
...  

Abstract. Vineyards are one of the eco-geomorphological systems most conditioned by human activity in Germany. The vineyards of the Ruwer Valley (Germany) are characterized by high soil erosion rates and rill problems on steep slopes (between 23 and 26°) caused by the increasingly frequent heavy rainfall events as well as deterioration due to incorrect land use managements. The objective of this paper is to determine and to quantify the hydrological and erosive phenomena in one vineyard in Germany during different seasons and under different management conditions (before, during and after vintage). For this purpose, a combined methodology was applied. Climatic (rainfall depth distributions and return periods), pedological (soil analysis and classification), geomorphological (sediment movements and rills evolution) and biological (botanic marks on the vines) variables were used on the two experimental plots in the village of Waldrach (Trier, region of Rhineland-Palatinate). The results showed high infiltration rates (near 100 %) and subsurface flow which were detected by rainfall simulations performed at different times of the year (between September and December). The highest variations of the monitored rills (lateral and frontal movements) were noted before and during vintage, when footsteps occurred concentrated during a short period of time (between September and October). Finally, two maps of soil loss were generated, indicated by botanic marks on the graft union of the vines. 62.5 t ha−1 yr−1 soil loss was registered in the experimental plots of the new vineyards (2 years), while 3.4 t ha−1 yr−1 was recorded in the old one (35 years).


1962 ◽  
Vol 59 (2) ◽  
pp. 225-232 ◽  
Author(s):  
J. A. F. Rook ◽  
R. C. Campling

1. The ‘availability’ of the magnesium of diets consisting solely of roughage or succulent feeds, including herbages cut at different seasons and at different stages of growth, and of diets of hay supplemented with various concentrate feeds, was assessed in metabolism trials conducted with two non-pregnant, non-lactating Shorthorn cows.2. The highest daily intakes of magnesium (1720 g./day) were provided by a diet of red clover: grasses and hays generally gave a considerably lower intake of magnesium (8–10 g./day), and most of the other diets provided intermediate amounts. However, with timothy hay and barley straw, intakes of 5 and 2 g./day, respectively, were recorded. Supplements to a diet of hay of dairy cubes or of oilcakes rich in protein gave a massive increase in magnesium intake but a supplement of flaked maize provided little additional magnesium.3. The ‘availability’ of the magnesium of the diets was generally low, within the range of 5–30%. With diets of single feeds no clear distinction between the various roughages and succulents in the ‘availability’ of their magnesium was established, though within the group of herbages the lowest values tended to occur with grasses cut at an early stage of growth and the highest values at the mature stage. A supplement of flaked maize increased the ‘availability’ of dietary magnesium and one of protein-rich oil cakes decreased the ‘availability’ of dietary magnesium.4. The results are discussed in relation to the development of hypomagnesaemia in cattle grazing spring pasture.


2020 ◽  
Vol 640 ◽  
pp. A58 ◽  
Author(s):  
A. Egal ◽  
P. G. Brown ◽  
J. Rendtel ◽  
M. Campbell-Brown ◽  
P. Wiegert

Aims. We present a multi-instrumental, multidecadal analysis of the activity of the Eta-Aquariid and Orionid meteor showers for the purpose of constraining models of 1P/Halley’s meteoroid streams. Methods. The interannual variability of the showers’ peak activity and period of duration is investigated through the compilation of published visual and radar observations prior to 1985 and more recent measurements reported in the International Meteor Organization (IMO) Visual Meteor DataBase, by the IMO Video Meteor Network and by the Canadian Meteor Orbit Radar (CMOR). These techniques probe the range of meteoroid masses from submilligrams to grams. The η-Aquariids and Orionids activity duration, shape, maximum zenithal hourly rates values, and the solar longitude of annual peaks since 1985 are analyzed. When available, annual activity profiles recorded by each detection network were measured and are compared. Results. Observations from the three detection methods show generally good agreement in the showers’ shape, activity levels, and annual intensity variations. Both showers display several activity peaks of variable location and strength with time. The η-Aquariids are usually two to three times stronger than the Orionids, but the two showers display occasional outbursts with peaks two to four times their usual activity level. CMOR observations since 2002 seem to support the existence of an ~12 yr cycle in Orionids activity variations; however, additional and longer term radar and optical observations of the shower are required to confirm such periodicity.


Author(s):  
Takehito Sugasawa ◽  
Seiko Ono ◽  
Masato Yonanine ◽  
Shin-ichiro Fujita ◽  
Yuki Matsumoto ◽  
...  

The prevalence of nonalcoholic fatty liver disease (NAFLD) has been rapidly increasing worldwide. A choline-deficient L-amino acid-defined high fat diet (CDHFD) has been used to create a mouse model of nonalcoholic steatohepatitis (NASH). There are some reports about the effects on mice of being fed CDAHFD for a long time, 1 to 3 months. However, the effect of this diet over a short period has been unknown. Therefore, we examined the effect of one week of feeding CDAHFD on the mouse liver. Feeding this diet for only one week induced lipid droplet deposition in the liver with increasing activity of liver-derived enzymes in the plasma. On the other hand, it did not induce fibrosis and cirrhosis. Additionally, it was demonstrated that mitochondrial respiration is significantly impaired with severe oxidative stress in the liver by CDAHFD, associated with a decreasing mitochondrial DNA copy number and complexes-proteins. In the gene expression analysis of the liver, inflammatory and oxidative stress markers were significantly increased by CDAHFD. These results demonstrated that one week of feeding CDAHFD to mice induces steatohepatitis with mitochondrial dysfunction and severe oxidative stress, without fibrosis, which can partially mimic the early stage of the NASH in humans.


Sign in / Sign up

Export Citation Format

Share Document