454 research outputs found
Metamorphism of the Oddanchatram anorthosite, Tamil Nadu, South India
The Oddanchatram anorthosite is located in the Madurai District of Tamil Nadu, near the town of Palni. It is emplaced into a granulite facies terrain commonly presumed to have undergone its last regional metamorphism in the late Archean about 2600 m.y. The surrounding country rock consists of basic granulites, charnockites and metasedimentary rocks including quartzites, pelites and calc-silicates. The anorthosite is clearly intrusive into the country rock and contains many large inclusions of previously deformed basic granulite and quartzite within 100 meters of its contact. Both this intrusion and the nearby Kaduvar anorthosite show evidence of having been affected by later metamorphism and deformation
Chemistry of the older supracrustals of Archaean age around Sargur
In the Archaeans of the Karnataka craton two stratigraphically distinct volcano-sedimentary sequences occur, namely the older supracrustals of the Sargur type and the younger Dharwar greenstones. The dividing line between these is the 3 by old component of the Peninsular gneiss. The trace and rare earth element chemistry of the Sargur metasediments show, in general, marked similarity to the Archaean sediments. The significant departures are in the nickel and chromium abundances. The REE data of the Sargur pelites of the Terakanambi region represented by Silli-gt-bio-feldspar schists and paragneisses show LREE enrichment and flat to depleted HREE pattern. Banded iron formations have very low REE abundance. They show slightly enriched LREE and flat to depleted HREE pattern. REE abundance in the Mn-horizons is comparable to that of the Archaean sediments. Mn-horizons show enriched LREE and flat HREE with anamolous Eu. REE patterns of these bands is well evolved and has similarities with PAAS
Unique Observations of a Geomagnetic SI^+ -- SI^- Pair: Solar Sources and Associated Solar Wind Fluctuations
The paper describes the occurrence of a pair of oppositely directed sudden
impulses (SI), in the geomagnetic field (X), at ground stations, called
SI -- SI pairs, that occurred between 1835 UT and 2300 UT on 23
April 1998. The SI -- SI pair, was closely correlated with
corresponding variations in the solar wind density, while solar wind velocity
and the southward component of the interplanetary magnetic field (Bz) did not
show any correspondence. Further, this event had no source on the visible solar
disk. However, a rear-side partial halo coronal mass ejection (CME) and an M1.4
class solar flare behind the west limb, took place on 20 April 1998, the date
corresponding to the traceback location of the solar wind flows. This event
presents empirical evidence, which to our knowledge, is the best convincing
evidence for the association of specific solar events to the observations of an
SI -- SI pair. In addition, it shows that it is possible for a
rear side solar flare to propagate a shock towards the earth.Comment: The paper has just been accepted in the Journal of Geophysical
Research (Space Physics) on 20 September 2010. It is 17 pages with 4 figure
Multi-wavelength study of the star-formation in the S237 H II region
We present a detailed multi-wavelength study of observations from X-ray,
near-infrared to centimeter wavelengths to probe the star formation processes
in the S237 region. Multi-wavelength images trace an almost sphere-like shell
morphology of the region, which is filled with the 0.5--2 keV X-ray emission.
The region contains two distinct environments - a bell-shaped cavity-like
structure containing the peak of 1.4 GHz emission at center, and elongated
filamentary features without any radio detection at edges of the sphere-like
shell - where {\it Herschel} clumps are detected. Using the 1.4 GHz continuum
and CO line data, the S237 region is found to be excited by a radio
spectral type of B0.5V star and is associated with an expanding H{\sc ii}
region. The photoionized gas appears to be responsible for the origin of the
bell-shaped structure. The majority of molecular gas is distributed toward a
massive {\it Herschel} clump (M 260 M), which
contains the filamentary features and has a noticeable velocity gradient. The
photometric analysis traces the clusters of young stellar objects (YSOs) mainly
toward the bell-shaped structure and the filamentary features. Considering the
lower dynamical age of the H\,{\sc ii} region (i.e. 0.2-0.8 Myr), these
clusters are unlikely to be formed by the expansion of the H\,{\sc ii} region.
Our results also show the existence of a cluster of YSOs and a massive clump at
the intersection of filamentary features, indicating that the collisions of
these features may have triggered cluster formation, similar to those found in
Serpens South region.Comment: 21 pages, 14 figures, 1 table, Accepted for publication in The
Astrophysical Journa
WhatsApp control: a new norm to succeed in LIMS adoption
Background: Adoption of the LIMS (laboratory information management system) serves varied purposes in the diagnostic laboratory and might take a very lengthy period for its implementation. But, without controls being put in place, it can create a barrier to the project’s execution and prevent it from being finished on time.
Methods: A WhatsApp group with 22 members, including lab technicians, heads of lab sections, a billing manager, an operations assistant manager, an assistant nursing caretaker, and administrative staff, was created. The assistant operations manager posted the daily pending report status in the WhatsApp group to help the lab team ratify, correct, and complete the assignments. To track pending report closures in real-time, the WhatsApp group mediated weekly follow-ups. The laboratory services department head informed the team monthly on the project’s status. The nonparametric Wilcoxon rank test and paired student t-test were performed to compare pre and post-survey responses before and after the seven-month intervention period.
Results: The non-parametric Wilcoxon rank test and paired t-test results of the post-test demonstrated that the participant’s answer had improved significantly since the pre-test. The questionnaire showed that participants liked the new WhatsApp control mechanism. The number of pending reports reduced from 4,000 to 240 in seven months, a statistically significant decrease at a p value of 0.01. This supports the newly implemented WhatsApp control.
Conclusions: Based on this interventional study, WhatsApp-based controls can be employed in conjunction with more conventional ways to regulate process outcomes during LIMS adoption
Splenic artery aneurysm: a case report with review of literature
Splenic Artery Aneurysm (SAA) is very rare in occurrence and they occur in approximately 1% of the population and are usually an incidental finding,but the necropsy studies have given rates as high as 10%. For its rarity in occurrence here we present a case of splenic artery aneurysm in a 40 year old alcoholic presenting with upper and lower gastrointestinal bleeding. He was diagnosed as splenic artery aneurysm on CT scan and confirmed by laparotomy and pathological examination
Privately Aligning Language Models with Reinforcement Learning
Positioned between pre-training and user deployment, aligning large language
models (LLMs) through reinforcement learning (RL) has emerged as a prevailing
strategy for training instruction following-models such as ChatGPT. In this
work, we initiate the study of privacy-preserving alignment of LLMs through
Differential Privacy (DP) in conjunction with RL. Following the influential
work of Ziegler et al. (2020), we study two dominant paradigms: (i) alignment
via RL without human in the loop (e.g., positive review generation) and (ii)
alignment via RL from human feedback (RLHF) (e.g., summarization in a
human-preferred way). We give a new DP framework to achieve alignment via RL,
and prove its correctness. Our experimental results validate the effectiveness
of our approach, offering competitive utility while ensuring strong privacy
protections
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