200 research outputs found
Jurassic frogs and the evolution of amphibian endemism in the Western Ghats
The diversity of frogs and toads (Anurans) in tropical
evergreen forests has recently gained importance with
reports of several new species1. We describe here a
fossorial frog taxon related to the African Heleophrynidae and Seychellian Sooglossidae from the Western Ghats of India. This frog possesses a suite of
unique ancient characters indicating that it is a transitional form between Archaeobatrachians and Neobatrachians. Molecular clock analysis based on the
nucleotide diversity in mitochondrial 12S and 16S genes dates this frog as a Gondwana relic, which evolved 150–195 Mya during the mid-Jurassic period.With this taxon, the evolution of endemism in the Western Ghats and other Gondwana break up landmasses is now dated much before the Cretaceous–Tertiary boundary. We propose that sea level surges in the late Jurassic2 isolated tablelands creating insular amphibian fauna. Reduction in area may have promoted stochastic extinctions and resulted in amphibian endemism. Our study reinforces the conservation significance of the Western Ghats as major global hotspot of biodiversity. The habitat of this endemic amphibian
lineage is currently endangered due to various upcoming
dam projects, which is a cause of serious conservation
concern
Management outcomes in pubic diastasis: our experience with 19 patients
<p>Abstract</p> <p>Background</p> <p>Pubic diastasis, a result of high energy antero-posterior compression (APC) injury, has been managed based on the Young and Burguess classification system. The mode of fixation in APC II injury has, however, been a subject of controversy and some authors have proposed a need to address the issue of partial breach of the posterior pelvic ring elements in these injuries.</p> <p>Methods</p> <p>The study included a total of 19 patients with pubic diastasis managed by us from May 2006 to December 2007. There was a single patient with type I APC injury who treated conservatively. Type II APC injuries (13 patients) were treated surgically with symphyseal plating using single anterior/superior plates or double perpendicularly placed plates. Type III injuries (5 patients) in addition underwent posterior fixation using plates or percutaneous sacro-iliac screws. The outcome was assessed clinically (Majeed score) and radiologically.</p> <p>Results</p> <p>The mean follow-up was for 2.9 years (6 months to 4.5 years). Among the 13 patients with APC II injuries, the clinical scores were excellent in one (7.6%), good in 6 (46.15%), fair in 4 (30.76%) and poor in 2 (15.38%). Radiological scores were excellent in 2 (15.38%), good in 8 (61.53%), fair in 2 (15.38%) and poor in one patient (7.6%). Among the 5 patients with APC III injuries, there were 2 patients each with good (50%) and fair (50%) clinical scores while one patient was lost on long term follow up. The radiological outcomes were also similar in these. Complications included implant failure in 3 patients, postoperative infection in 2 patients, deep venous thrombosis in one patient and bladder herniation in one of the patients with implant failure.</p> <p>Conclusions</p> <p>There is no observed dissimilarity in outcomes between isolated anterior and combined symphyseal (perpendicular) plating techniques in APC II injuries. Single anterior symphyseal plating along with posterior stabilisation provides a stable fixation in type III APC injuries. Limited dissection ensuring adequate intactness of rectus sheath is important to avoid long term post-operative complications.</p
Development of new genomic microsatellite markers from robusta coffee (Coffea canephora Pierre ex A. Froehner) showing broad cross-species transferability and utility in genetic studies
<p>Abstract</p> <p>Background</p> <p>Species-specific microsatellite markers are desirable for genetic studies and to harness the potential of MAS-based breeding for genetic improvement. Limited availability of such markers for coffee, one of the most important beverage tree crops, warrants newer efforts to develop additional microsatellite markers that can be effectively deployed in genetic analysis and coffee improvement programs. The present study aimed to develop new coffee-specific SSR markers and validate their utility in analysis of genetic diversity, individualization, linkage mapping, and transferability for use in other related taxa.</p> <p>Results</p> <p>A small-insert partial genomic library of <it>Coffea canephora</it>, was probed for various SSR motifs following conventional approach of Southern hybridisation. Characterization of repeat positive clones revealed a very high abundance of DNRs (1/15 Kb) over TNRs (1/406 kb). The relative frequencies of different DNRs were found as AT >> AG > AC, whereas among TNRs, AGC was the most abundant repeat. The SSR positive sequences were used to design 58 primer pairs of which 44 pairs could be validated as single locus markers using a panel of arabica and robusta genotypes. The analysis revealed an average of 3.3 and 3.78 alleles and 0.49 and 0.62 PIC per marker for the tested arabicas and robustas, respectively. It also revealed a high cumulative PI over all the markers using both sib-based (10<sup>-6 </sup>and 10<sup>-12 </sup>for arabicas and robustas respectively) and unbiased corrected estimates (10<sup>-20 </sup>and 10<sup>-43 </sup>for arabicas and robustas respectively). The markers were tested for Hardy-Weinberg equilibrium, linkage dis-equilibrium, and were successfully used to ascertain generic diversity/affinities in the tested germplasm (cultivated as well as species). Nine markers could be mapped on robusta linkage map. Importantly, the markers showed ~92% transferability across related species/genera of coffee.</p> <p>Conclusion</p> <p>The conventional approach of genomic library was successfully employed although with low efficiency to develop a set of 44 new genomic microsatellite markers of coffee. The characterization/validation of new markers demonstrated them to be highly informative, and useful for genetic studies namely, genetic diversity in coffee germplasm, individualization/bar-coding for germplasm protection, linkage mapping, taxonomic studies, and use as conserved orthologous sets across secondary genepool of coffee. Further, the relative frequency and distribution of different SSR motifs in coffee genome indicated coffee genome to be relatively poor in microsatellites compared to other plant species.</p
Genetic heterogeneity in wild isolates of cellular slime mold social groups
This study addresses the issues of spatial distribution, dispersal, and genetic heterogeneity in social groups of the cellular slime molds (CSMs). The CSMs are soil amoebae with an unusual life cycle that consists of alternating solitary and social phases. Because the social phase involves division of labor with what appears to be an extreme form of "altruism", the CSMs raise interesting evolutionary questions regarding the origin and maintenance of sociality. Knowledge of the genetic structure of social groups in the wild is necessary for answering these questions. We confirm that CSMs are widespread in undisturbed forest soil from South India. They are dispersed over long distances via the dung of a variety of large mammals. Consistent with this mode of dispersal, most social groups in the two species examined for detailed study, Dictyostelium giganteum and Dictyostelium purpureum, are multi-clonal
Intra and extraarticular localized pigmented villonodular synovitis
A 28 year old woman had a history of knee trauma and presented with unilateral knee acute swelling and pain symptoms with sudden onset, which was there from last 2 years. She had been treated for seronegative rheumatoid patient for 1 year. Recent expansion of the LPVNS (localized pigmented villonodular synovitis) caused the development of a tender palpable soft tissue mass in the anterolateral aspect of the knee and acute reduced mobility. Preoperative magnetic resonance imaging of the knee revealed the presence of only the soft tissue mass and mild degenerative changes. Open synovectomy was performed successfully to excise the mass. Intraoperatively, macroscopic features of the bright brown inflamed synovium suggested LPVNS, which was confirmed histopathologically. Postoperatively, the symptoms of limited mobility and pain were appreciably relieved. Recurrence was not observed during the clinical follow up at 1, 6 or 18 months after surgery. Here, we reported the unique case of localized pigmented villonodular synovitis of the knee in a misdiagnosed patient with intra and extraarticular lesion, which might be attributed to the history of knee trauma and the focal defect of the lateral patellar retinaculum. Open synovectomy effectively relieved the symptoms of limited mobility and pain and no recurrence was observed prior to 18 months postoperatively. To reduce misdiagnosis, MRI examinations are recommended for all patients suspected of having PVNS, including those who have a history of hyperuricemia
Cloning and sequencing of complete τ-crystallin cDNA from embryonic lens of Crocodylus palustris
τ-Crystallin is a taxon-specific structural protein found in eye lenses. We present here the cloning and sequencing of complete τ-crystallin cDNA from the embryonic lens of Crocodylus palustris and establish it to be identical to the τ-enolase gene from non-lenticular tissues. Quantitatively, the τ-crystallin was found to be the least abundant crystallin of the crocodilian embryonic lenses. Crocodile τ-crystallin cDNA was isolated by RT-PCR using primers designed from the only other reported sequence from duck and completed by 5'- and 3'-rapid amplification of cDNA ends (RACE) using crocodile gene specific primers designed in the study. The complete τ-crystallin cDNA of crocodile comprises 1305 bp long ORF and 92 and 409 bp long untranslated 5'- and 3'-ends respectively. Further, it was found to be identical to its putative counterpart enzyme τ-enolase, from brain, heart and gonad, suggesting both to be the product of the same gene. The study thus provides the first report on cDNA sequence of τ-crystallin from a reptilian species and also re-confirms it to be an example of the phenomenon of gene sharing as was demonstrated earlier in the case of peking duck. Moreover, the gene lineage reconstruction analysis helps our understanding of the evolution of crocodilians and avian species
Complementary feeding at 4 versus 6 months of age for preterm infants born at less than 34 weeks of gestation: a randomised, open-label, multicentre trial
Background Evidence on the optimal time to initiation of complementary feeding in preterm infants is scarce.
We examined the effect of initiation of complementary feeding at 4 months versus 6 months of corrected age on
weight for age at 12 months corrected age in preterm infants less than 34 weeks of gestation.
Methods In this open-label, randomised trial, we enrolled infants born at less than 34 weeks of gestation with no major
malformation from three public health facilities in India. Eligible infants were tracked from birth and randomly
assigned (1:1) at 4 months corrected age to receive complementary feeding at 4 months corrected age (4 month group), or
continuation of milk feeding and initiation of complementary feeding at 6 months corrected age (6 month group), using
computer generated randomisation schedule of variable block size, stratified by gestation (30 weeks or less, and
31–33 weeks). Iron supplementation was provided as standard. Participants and the implementation team could not be
masked to group assignment, but outcome assessors were masked. Primary outcome was weight for age Z-score at
12 months corrected age (WAZ12) based on WHO Multicentre Growth Reference Study growth standards. Analyses were
by intention to treat. The trial is registered with Clinical Trials Registry of India, number CTRI/2012/11/003149.
Findings Between March 20, 2013, and April 24, 2015, 403 infants were randomly assigned: 206 to receive
complementary feeding from 4 months and 197 to receive complementary feeding from 6 months. 22 infants in the
4 month group (four deaths, two withdrawals, 16 lost to follow-up) and eight infants in the 6 month group (two deaths,
six lost to follow-up) were excluded from analysis of primary outcome. There was no difference in WAZ12 between
two groups: –1·6 (SD 1·2) in the 4 month group versus –1·6 (SD 1·3) in the 6 month group (mean difference 0·005,
95% CI –0·24 to 0·25; p=0·965). There were more hospital admissions in the 4 month group compared with the
6 month group: 2·5 episodes per 100 infant-months in the 4 month group versus 1·4 episodes per 100 infant-months
in the 6 month group (incidence rate ratio 1·8, 95% CI 1·0–3·1, p=0·03). 34 (18%) of 188 infants in the 4 month
group required hospital admission, compared with 18 (9%) of 192 infants in the 6 month group.
Interpretation Although there was no evidence of effect for the primary endpoint of WAZ12, the higher rate of hospital
admission in the 4 month group suggests a recommendation to initiate complementary feeding at 6 months over
4 months of corrected age in infants less than 34 weeks of gestation
Minimal hepatic encephalopathy: consensus statement of a working party of the Indian National Association for study of the liver
Hepatic encephalopathy (HE) is a major complication that develops in some form and at some stage in a majority of patients with liver cirrhosis. Overt HE occurs in approximately 30-45% of cirrhotic patients. Minimal HE (MHE), the mildest form of HE, is characterized by subtle motor and cognitive deficits and impairs health-related quality of life. The Indian National Association for Study of the Liver (INASL) set up a Working Party on MHE in 2008 with a mandate to develop consensus guidelines on various aspects of MHE relevant to clinical practice. Questions related to the definition of MHE, its prevalence, diagnosis, clinical characteristics, pathogenesis, natural history and treatment were addressed by the members of the Working Party
Stereospecific conversion of alcohols into pinacol boronic esters using lithiation-borylation methodology with pinacolborane
The synthesis of primary and secondary pinacol boronic esters via
lithiation–borylation of carbamates and benzoates with pinacolborane is described. This new protocol enables the highly selective
synthesis of enantioenriched and geometrically defined boronic esters
that cannot otherwise be accessed by alternative methodologies
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