140 research outputs found
Contraceptive Choice Among Married Women In Guizhou Province : Socio-Cultural And Relationship Factors [HQ766.5.C6 L926 2008 f rb].
Kajian ini menganalisis perbezaan ketara dalam amalan perancangan keluarga dan tren di daerah Guizhou berbanding dengan daerah lain di negara China walaupun terdapat hanya satu polisi yang sama bagi seluruh negara,
This study analysed the stark difference of family planning practices and trends in Guizhou Province compared to the other provinces in China despite one common family planning policy for the whole of Chin
Why does the apparent mass of a coronal mass ejection increase?
Mass is one of the most fundamental parameters characterizing the dynamics of
a coronal mass ejection (CME). It has been found that CME apparent mass
measured from the brightness enhancement in coronagraph images shows an
increasing trend during its evolution in the corona. However, the physics
behind it is not clear. Does the apparent mass gain come from the mass outflow
from the dimming regions in the low corona, or from the pileup of the solar
wind plasma around the CME when it propagates outwards from the Sun? We
analyzed the mass evolution of six CME events. Their mass can increase by a
factor of 1.6 to 3.2 from 4 to 15 Rs in the field of view (FOV) of the
coronagraph on board the Solar Terrestrial Relations Observatory (STEREO). Over
the distance about 7 to 15 Rs, where the coronagraph occulting effect can be
negligible, the mass can increase by a factor of 1.3 to 1.7. We adopted the
`snow-plough' model to calculate the mass contribution of the piled-up solar
wind in the height range from about 7 to 15 Rs. For 2/3 of the events, the
solar wind pileup is not sufficient to explain the measured mass increase. In
the height range from about 7 to 15 Rs, the ratio of the modeled to the
measured mass increase is roughly larger than 0.55. Although the ratios are
believed to be overestimated, the result gives evidence that the solar wind
pileup probably makes a non-negligible contribution to the mass increase. It is
not clear yet whether the solar wind pileup is a major contributor to the final
mass derived from coronagraph observations. However, our study suggests that
the solar wind pileup plays increasingly important role in the mass increase as
a CME moves further away from the Sun.Comment: 27 pages, 2 tables, 9 figures, accepted by Ap
Characteristics of events with metric-to-decahectometric type II radio bursts associated with CMEs and flares in relation to SEP events
A gradual solar energetic particle (SEP) event is thought to happen when
particles are accelerated at a shock due to a fast coronal mass ejection (CME).
To quantify what kind of solar eruptions can result in such SEP events, we have
conducted detailed investigations on the characteristics of CMEs, solar flares
and m-to-DH wavelength type II radio bursts (herein after m-to-DH type II
bursts) for SEP-associated and non-SEP-associated events, observed during the
period of 1997-2012. Interestingly, 65% of m-to-DH type II bursts associated
with CMEs and flares produced SEP events. The SEP-associated CMEs have higher
sky-plane mean speed, projection corrected speed, and sky-plane peak speed than
those of non-SEP-associated CMEs respectively by 30%, 39%, and 25%, even though
the two sets of CMEs achieved their sky-plane peak speeds at nearly similar
heights within LASCO field of view. We found Pearson's correlation coefficients
between the speeds of CMEs speeds and logarithmic peak intensity of SEP events
are cc = 0.62 and cc = 0.58, respectively. We also found that the
SEP-associated CMEs are on average of three times more decelerated (-21.52
m/s2) than the non-SEP-associated CMEs (-5.63 m/s2). The SEP-associated m type
II bursts have higher frequency drift rate and associated shock speed than
those of the non-SEP-associated events by 70% and 25% respectively. The average
formation heights of m and DH type II radio bursts for SEP-associated events
are lower than for non-SEP-associated events. 93% of SEP-associated events
originate from the western hemisphere and 65% of SEP-associated events are
associated with interacting CMEs. The obtained results indicate that, at least
for the set of CMEs associated with m-to-DH type II bursts, SEP-associated CMEs
are more energetic than those not associated with SEPs, thus suggesting that
they are effective particle accelerators.Comment: 19 pages, 10 figures, 3 tables, accepted for publication by ApS
Effect of various dietary fats on fatty acid profile in duck liver: Efficient conversion of short-chain to long-chain omega-3 fatty acids
Citation: Chen, X., Du, X., Shen, J., Lu, L., & Wang, W. (2016). Effect of various dietary fats on fatty acid profile in duck liver: Efficient conversion of short-chain to long-chain omega-3 fatty acids. Experimental Biology and Medicine, 1535370216664031. https://doi.org/10.1177/1535370216664031Omega-3 fatty acids, especially long-chain omega-3 fatty acids, have been associated with potential health benefits for chronic disease prevention. Our previous studies found that dietary omega-3 fatty acids could accumulate in the meat and eggs in a duck model. This study was to reveal the effects of various dietary fats on fatty acid profile and conversion of omega-3 fatty acids in duck liver. Female Shan Partridge Ducks were randomly assigned to five dietary treatments, each consisting of 6 replicates of 30 birds. The experimental diets substituted the basal diet by 2% of flaxseed oil, rapeseed oil, beef tallow, or fish oil, respectively. In addition, a dose response study was further conducted for flaxseed and fish oil diets at 0.5%, 1%, and 2%, respectively. At the end of the five-week treatment, fatty acids were extracted from the liver samples and analyzed by GC-FID. As expected, the total omega-3 fatty acids and the ratio of total omega-3/omega-6 significantly increased in both flaxseed and fish oil groups when compared with the control diet. No significant change of total saturated fatty acids or omega-3 fatty acids was found in both rapeseed and beef tallow groups. The dose response study further indicated that 59Ð81% of the short-chain omega-3 ALA in flaxseed oil-fed group was efficiently converted to long-chain DHA in the duck liver, whereas 1% of dietary flaxseed oil could produce an equivalent level of DHA as 0.5% of dietary fish oil. The more omega-3 fatty acids, the less omega-6 fatty acids in the duck liver. Taken together, this study showed the fatty acid profiling in the duck liver after various dietary fat consumption, provided insight into a dose response change of omega-3 fatty acids, indicated an efficient conversion of short- to long-chain omega-3 fatty acid, and suggested alternative long-chain omega-3 fatty acid-enriched duck products for human health benefits
Molecular Characterization and Expression of α-Globin and β-Globin Genes in the Euryhaline Flounder (Platichthys flesus)
In order to understand the possible role of globin genes in fish salinity adaptation, we report the molecular characterization and expression of all four subunits of haemoglobin, and their response to salinity challenge in flounder. The entire open reading frames of α1-globin and α2-globin genes were 432 and 435 bp long, respectively, whereas the β1-globin and β2-globin genes were both 447 bp. Although the head kidney (pronephros) is the predicted major site of haematopoiesis, real-time PCR revealed that expression of α-globin and β-globin in kidney (mesonephros) was 1.5 times higher than in head kidney. Notably, the α1-globin and β1-globin mRNA expression was higher than α2-globin and β2-globin in kidney. Expression levels of all four globin subunits were higher in freshwater- (FW-) than in seawater- (SW-)adapted fish kidney. If globins do play a role in salinity adaptation, this is likely to be more important in combating the hemodilution faced by fish in FW than the dehydration and salt loading which occur in SW
Transcriptomic variation of hepatopancreas reveals the energy metabolism and biological processes associated with molting in Chinese mitten crab, Eriocheir sinensis
Molting is a critical developmental process for crustaceans, yet the underlying molecular mechanism is unknown. In this study, we used RNA-Seq to investigate transcriptomic profiles of the hepatopancreas and identified differentially expressed genes at four molting stages of Chinese mitten crab (Eriocheir sinensis). A total of 97,398 transcripts were assembled, with 31,900 transcripts annotated. Transcriptomic comparison revealed 1,189 genes differentially expressed amongst different molting stages. We observed a pattern associated with energy metabolism and physiological responses during a molting cycle. In specific, differentially expressed genes enriched in postmolt were linked to energy consumption whereas genes enriched in intermolt were related to carbohydrates, lipids metabolic and biosynthetic processes. In premolt, a preparation stage for upcoming molting and energy consumption, highly expressed genes were enriched in response to steroid hormone stimulus and immune system development. The expression profiles of twelve functional genes detected via RNA-Seq were corroborated through real-time RT-PCR assay. Together, our results, including assembled transcriptomes, annotated functional elements and enriched differentially expressed genes amongst different molting stages, provide novel insights into the functions of the hepatopancreas in energy metabolism and biological processes pertaining to molting in crustaceans
Properties of a Small-scale Short-duration Solar Eruption with a Driven Shock
Large-scale solar eruptions have been extensively explored over many years.
However, the properties of small-scale events with associated shocks have been
rarely investigated. We present the analyses of a small-scale short-duration
event originating from a small region. The impulsive phase of the M1.9-class
flare lasted only for four minutes. The kinematic evolution of the CME hot
channel reveals some exceptional characteristics including a very short
duration of the main acceleration phase ( 2 minutes), a rather high maximal
acceleration rate (50 km s) and peak velocity (1800 km
s). The fast and impulsive kinematics subsequently results in a
piston-driven shock related to a metric type II radio burst with a high
starting frequency of 320 MHz of the fundamental band. The type II source
is formed at a low height of below less than
minutes after the onset of the main acceleration phase. Through the band split
of the type II burst, the shock compression ratio decreases from 2.2 to 1.3,
and the magnetic field strength of the shock upstream region decreases from 13
to 0.5 Gauss at heights of 1.1 to 2.3 . We find that the
CME () and flare
() consume similar amount of magnetic
energy. The same conclusion for large-scale eruptions implies that small- and
large-scale events possibly share the similar relationship between CMEs and
flares. The kinematic particularities of this event are possibly related to the
small footpoint-separation distance of the associated magnetic flux rope, as
predicted by the Erupting Flux Rope model.Comment: 20 pages, 16 figure
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