5,072 research outputs found
Thin layer chromatographic separation of lipids in ovary, testis and gut of the sea urchin Salmacis virgulata
Sea urchins accumulate large amounts of lipid in ovary during
its reproductive cycle (Giese, 1966 ; Vivek Raja, 1980); Lipids
deposited in the developing gonads may be synthesized within
the oocytes or transported from the gut. A variety of lipid
classes are also found to occur in the ovary, testis, gut, body
wall and coelomocytes of the sea urchins (Allen, 1974; Vivek
Raja, 1980). The present experiment is designed to separate
and identify the different lipid classes present in gut, testis and
ovary of the sea urchin Salmacis virgulata employing thin layer
chromatographic metho
Determination of reproductive activity in sea urchins
The most widely used quantitative method for assessing the
reproductive activity is the gonad index (Giese and Pearse, 1974).
But, in species such as sea urchins possessing considerable
quantities of nutritive tissues in the gonad, both an increase
and a decrease in gonad index may be a consequence of changes.
in the number of nutritive cells without a corresponding change
in gametogenic cell
Induced spawning in sea urchins
The gonad wall of the sea urchin consists of an outer epithelium,
the outer surface of which is bathed in the perivisceral fluid,
a middle layer of conspicuous bands of smooth muscles and
connective tissue and an inner layer of developing gametes with
nutritive cells (Vivek Raja, 1980). The release of gametes, in
nature is effected by the contraction of the muscular bands which
is directly under the stimulatory effect of the radial nerve hormone
(Cochran and Engelmann, 1972). The gamete discharge may
be induced by acetylcholine, potassium chloride or by electrical
stimulation
QRM CONSIDERATIONS FOR MEDICINES REGULATORY AUTHORITIES
Risk management principles are effectively utilized in many areas of business and government including finance, insurance, occupational safety, public health, pharmacovigilance, and by agencies regulating these industries. In regulatory perspective it is used to assist with resource allocation including, for example, inspection planning and frequency, and inspection and assessment intensity. It is also helps evaluate the significance of products; like quality defects, potential recalls and inspectional findings. It is also find its potential; appropriateness and type of postinspection regulatory follow-up To identify risks that should be communicated between inspectors and assessors to facilitate better understanding of how risks can be or are controlled (e.g., parametric release, Process Analytical Technology (PAT)). In short QRM has become a mandatory regulatory requirement towards healthcare organizations
SDSS J092712.64+294344.0: recoiling black hole or merging galaxies?
We report long-slit spectroscopic observations of SDSS J092712+294344
carried-out at the recently commissioned 2m telescope in IUCAA Girawali
Observatory, India. This AGN-like source is known to feature three sets of
emission lines at zem = 0.6972, 0.7020 and 0.7128. Different scenarios such as
a recoiling black hole after asymmetric emission of gravitational waves, binary
black holes and possible merging systems are proposed for this object. We test
these scenarios by comparing our spectra with that from the Sloan Digital Sky
Survey (SDSS), obtained 4 years prior to our observations. Comparing the
redshifts of [OIII]4960,5008 we put a 3 sigma limit on the relative
acceleration to be less than 32 km s^-1 yr^-1 between different emitting
regions. Using the 2D spectra obtained at different position angles we show
that the [OIII]5008 line from the zem = 0.7128 component is extended beyond the
spectral point spread function. We infer the linear extent of this line
emitting region is ~8 kpc. We also find a tentative evidence for an offset
between the centroid of the [OIII]5008 line at zem = 0.7128 and the QSO trace
when the slit is aligned at a position angle of 299 degrees. This corresponds
to the zem = 0.7128 system being at an impact parameter of ~1 kpc with respect
to the zem = 0.6972 in the north west direction. Based on our observations we
conclude that the binary black hole model is most unlikely. The spatial extent
and the sizes are consistent with both black hole recoil and merging scenarios.Comment: accepted for publication in MNRAS Letter
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