758 research outputs found
A test of tau neutrino interactions with atmospheric neutrinos and K2K
The presence of a tau component in the flux of atmospheric neutrinos inside
the Earth, due to flavor oscillations, makes these neutrinos a valuable probe
of interactions of the tau neutrino with matter. We study -- analytically and
numerically -- the effects of nonstandard interactions in the nu_e-nu_tau
sector on atmospheric neutrino oscillations, and calculate the bounds on the
exotic couplings that follow from combining the atmospheric neutrino and K2K
data. We find very good agreement between numerical results and analytical
predictions derived from the underlying oscillation physics. While improving on
existing accelerator bounds, our bounds still allow couplings of the size
comparable to the standard weak interaction. The inclusion of new interactions
expands the allowed region of the vacuum oscillation parameters towards smaller
mixing angles, 0.2 ~< sin^2 theta_{23} ~< 0.7, and slightly larger mass squared
splitting, 1.5 * 10^{-3} eV^2 ~< |\Delta m^2_{23}| ~< 4.0 * 10^{-3} eV^2,
compared to the standard case. The impact of the K2K data on all these results
is significant; further important tests of the nu_e-nu_tau exotic couplings
will come from neutrino beams experiments such as MINOS and long baseline
projects.Comment: 8 figures, some typos corrected, minor editing in the reference
Effect of screentime in college students during the COVID-19 online classes on their neck posture and postural control: an observational study
Background: Corona virus which is the source of severe acute pulmonary syndrome causes an airway tract contamination (COVID 19). Prolonged sitting for online classes in the college students leads to the enlarged postural deviation, increased low back pain. Prolonged static contraction of skeletal muscles of the cervical region, lower back leads to impaired flow of blood to the muscle groups together with edema and accumulation of waste metabolites will trigger the muscle spasm.
Methods: Total 30 college students aged between 18-25 years who attended the online classes during COVID-19 were included in this study by using a questionnaire. The outcome measures used were the measurement of CV angle, SEBT and BBS. The postural control was estimated by using star excursion balance test and Berg balance scale.
Results: Using Karl Pearson’s correlation coefficient, a positive correlation was observed between CV angle and BBS (r = 0.82). Between BMI and CV angle there exists a statistically significant negative correlation (r = -0.564).
Conclusions: This study proved that there exists a forward neck posture in the students who attended the online classes during the COVID-19 pandemic and that also affected their postural control
Checklist of marine bivalves and gastropods off Kollam, Kerala
Species diversity of any region can be illustrated
by means of an available checklist. It provides an
overview of the species that have been recorded.
and can be considered to understand the local
fauna. Fortnightly surveys were carried out to
collect the shell-molluscs samples during 2012 - 2014
period from the by-catch of shrimp/fish trawlers
landed at Sakthikulangara-Neendakara Fishing
Harbour, Kollam. Collected bivalves and gastropods
included both empty shells and living animals.
Collected shells were brought to the laboratory and
placed in freezer for 24 hours. This would liquefy
the mollusc body and allowed easy extraction with
a strong jet of water
Thermal expansion of doped lanthanum gallates
Thermal expansion of several compositions of Sr and Mg-doped LaGaO3 including an A-site deficient composition (La0.9Sr0.1)0.98(Ga0.8Mg0.2)O2.821 were measured in the temperature range from 298 to 1273 K. The effect of doping on thermal expansion was studied by varying the composition at one site of the perovskite structure (either A or B), while keeping the composition at the other site invariant. Thermal expansion varied nonlinearly with temperature and exhibited an inflexion between 550 and 620 K, probably related to the change in crystal structure from orthorhombic to rhombohedral. The dependence of average thermal expansion coefficient (α av) on the dopant concentration on either A or B site of the perovskite structure was found to be linear, when the composition at the other site was kept constant. Mg doping on the B-site had a greater effect on the average thermal expansion coefficient than Sr doping on the A-site. Cation deficiency at the A-site decreases thermal expansion when compositions at both sites are held constant
Rare observation of scar-bearing cuttlebone in a wild-caught Sepia pharaonis (Cephalopoda: Sepiidae) from southeastern Arabian Sea
A rare observation of the severely fractured cum healing cuttlebone of wild-caught Sepia pharaonis is reported and discussed here. The observation showed that cuttlebone of one specimen was severely affected by scars. Scars were interpreted as oval-shaped teeth marks on the dorsal side having a diameter of 23 mm. Several other teeth marks (3-4 numbers) were also observed at the anterodorsal region. Fracture was completely healed at the dorsal side while fracture (19 mm length) was notable in posteroventral region. Inverted ‘V’shaped blackline was also observed on the posteroventral region. However, scar-bearing cuttlebones was more or less symmetrical with respect to the sagittal plane
Scope for light assisted fishing in Southeastern Arabian Sea
Scope for light assisted fishing in
Southeastern Arabian Se
Mussel Culture
Mariculture of bivalves greater importance in meeting the
increasing protein demands of the human population. Bivalve
groups such as oyster, mussel and clam are the most important
cultivable organisms all over the world. Of these, P. viridis
andP.indica forms the most dominant cultivable species. The
Central Marine Fisheries Research Institute (CMFRI) has developed
eco-friendly techniques for mussel culture. Recently, CMFRI has
taken up efforts to popularize mussel culture in all coastal districts
of Kerala
Rare occurrence of Reinhardt’s cranch squid Liocranchia reinhardti (Cephalopod: Cranchiidae) from southeastern Arabian Sea
Single individual of the rare cranchiid squid Liocranchia reinhardti
belonging to the Cranchiidae family was caught in a bottom trawl
operated at 80 m in southeastern Arabian Sea. The morphometric
measurements and indices of the specimen are provided. Statolith
microstructure analysis revealed that the L. reinhardti with 118 mm
dorsal mantle length (DML) had an age of 71 days with growth rate of
1.66 mm DML/day
Oyster Farming Techniques
Oysters, mussels, clams, scallops, cockles and abalones are major
groups of molluscs which are cultured in different parts of the
world. Edible oysters are the most important among them, as they
are great delicacy and there is growing demand. There is an
increasing interest in oyster culture in tropical countries in recent
years. In India there is a growing demand for oyster meat in some
parts of the country. They are highly esteemed sea food and
considered a delicacy in USA, Europe, Japan etc. It is said that
‘oyster’ is scientifically the best known marine animal. It is one of
the most widely cultivated species. As early as the first century BC
the Romans were the first to develop simple methods of collecting
oyster seeds and growing them for food
Paralarva of the sharpear enope squid Ancistrocheirus lesueurii (Oegopsida: Ancistrocheiridae) in the southeastern Arabian Sea
First morphological description of an early stage paralarva of the
sharpear enope squid Ancistrocheirus lesueurii from southeastern
Arabian Sea is presented. The paralarva was collected at dusk by
using surface tows of zooplankton nets in February 2012. The
presence of paralarva A. lesueurii indicates that this species
completes its life cycle in this sea. A comparison of the arm
formula of paralarva and adult stages shows a major change in
the formula during metamorphosis to adult
- …