146 research outputs found
Role of diffusion Weighted Imaging (DWI) in determining response to neoadjuvant chemoradiation in locally advanced carcinoma rectum
OBJECTIVES:
To assess the role of DWI in predicting response to neoadjuvant chemoradiotherapy in patients with locally advanced carcinoma rectum (LARC) compared with T2W imaging. Secondarily, to evaluate the accuracy of tumour regression grade (TRG) assessed using MRI (T2W and DWI) in comparison with histopathological TRG.
METHODS:
A prospective analysis of 70 patients with LARC, who underwent neoadjuvant CRT and subsequent surgery was done. All patients underwent pre- and post-CRT T2W MR and DWI. The tumour volumes on T2W and DW images, difference in tumour volumes, pre and post-CRT ADC, difference in tumour ADC were measured. The TRG on T2W MRI and DWI were independently assessed. Histopathologic tumour regression grade was the standard of reference. The diagnostic accuracy of the tests in predicting complete response was compared using ROC analysis. The agreement between the MR tumour regression grades and histopathology was assessed using kappa statistic.
RESULTS:
The range of volumetric and ADC values in each TRG category were derived. The groups were subdivided into complete response (CR, n=13) and non-CR groups. Tumour volume reduction rate (TVRR) calculated on DWI and T2W MR were both useful in assessing complete response, with the accuracy of DWI being superior (AUC 0.92 for DWI vs 0.72 for T2W). The tumour ADC increase rate (TAIR) and absolute increase (ΔADC) though statistically significant as a predictor of response was inferior to tumour volumetry on DWI (AUC 0.7). Using a cut-off value for the tumour volume reduction rate of more than 94% on DWI, the sensitivity and specificity for predicting CR was 83.3% with NPV of 95.7%.
There was fair agreement between the TRG based on MRI (76.4%, kappa 0.25, p <0.01) /DWI (74.6%, kappa 0.24, p <0.01) and histopathological TRG Pre- and post-CRT volumetry, ADC values when viewed independently were not reliable.
CONCLUSION:
The parameters found to be of significance in assessing response to neoadjuvant CRT are tumour volume reduction rate - TVRR on DWI and T2W, tumour ADC increase rate – TAIR and ΔADC. Among these, volumetry based on DWI was superior with high diagnostic accuracy in predicting complete response. TVRR based on T2W and changes in ADC values had similar diagnostic accuracies.
Tumour regression grade assessed using T2W MRI and DWI are also useful as prognostic markers for disease recurrence and overall survival
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Geospatial approach for assessing spatiotemporal dynamics of urban green space distribution among neighbourhoods: A demonstration in Mumbai
Green spaces are an integral part of urban landscape and offer numerous benefits related to quality of urban life. However, due to various factors, the distribution of green spaces among city neighbourhoods is often skewed. Hence, urban planners require effective tools to routinely map and monitor the greening/ un-greening phenomena among the neighbourhoods. This study caters to this need by adopting a geospatial green space distribution assessment approach that encompasses green space quantity, quality and accessibility aspects. The green space distribution indicators were derived from remote sensing data, which facilitates cost-effective green space assessments at desired time scales. In this study, the approach is demonstrated in Mumbai, a typical city in a developing country undergoing urbanization transition accompanied by stark environmental challenges. The study results revealed that the green spaces in Mumbai had generally diminished, fragmented and disaggregated between 2001 and 2011. However, the level of degeneration of green spaces was found to vary significantly among the neighbourhoods. The results also unveiled that the verdant spaces in the city's western suburbs had experienced the worst degradation during the study period. These results would aid Mumbai's planners in formulating local greening strategies in a cost-effective manner. Further, the study has wider implications for green space planning, especially in the understudied, fast-urbanizing developing countries
ANALYSIS OF NONNEGATIVE LEAST SQUARES ALGORITHMS
Nonnegative least squares problems (NNLS) which are least squares solutions
that are constrained to take nonnegative values often arise in many applications like
image processing, data mining, etc. There have been several approaches to solve such a
problem like the active set method by Lawson and Hanson, FNNLS by Bro and Jong, the
Quasi-Newton minimization method, and Randomized projections methods. In this
thesis, we evaluated the performance properties of all these algorithms by implementing
them in MATLAB and compared the results. The results obtained showed that
Randomized projections seem to work very efficiently, producing results around 3 times
faster than Quasi-Newton method with a relative error of 3.25% for randomly generated
matrices using MATLAB
Using distance sampling with camera traps to estimate the density of group-living and solitary mountain ungulates
This work is part of a project initiated under the National Mission for Sustaining the Himalayan Ecosystem (NMSHE) Programme funded by the Department of Science and Technology, Government of India (grant no.: DST/SPLICE/CCP/NMSHE/TF-2/WII/2014[G]). The Miriam Rothschild Travel Bursary Programme provided funding for a 4-week internship for R. Pal with S.T. Buckland at St Andrews University, UK.Throughout the Himalaya, mountain ungulates are threatened by hunting for meat and body parts, habitat loss, and competition with livestock. Accurate population estimates are important for conservation management but most of the available methods to estimate ungulate densities are difficult to implement in mountainous terrain. Here, we tested the efficacy of the recent extension of the point transect method, using camera traps for estimating density of two mountain ungulates: the group-living Himalayan blue sheep or bharal Pseudois nayaur and the solitary Himalayan musk deer Moschus leucogaster. We deployed camera traps in 2017-2018 for the bharal (summer: 21 locations; winter: 25) in the trans-Himalayan region (3,000-5,000 m) and in 2018-2019 for the musk deer (summer: 30 locations; winter: 28) in subalpine habitats (2,500-3,500 m) in the Upper Bhagirathi basin, Uttarakhand, India. Using distance sampling with camera traps, we estimated the bharal population to be 0.51 ± SE 0.1 individuals/km2 (CV = 0.31) in summer and 0.64 ± SE 0.2 individuals/km2 (CV = 0.37) in winter. For musk deer, the estimated density was 0.4 ± SE 0.1 individuals/km2 (CV = 0.34) in summer and 0.1 ± SE 0.05 individuals/km2 (CV = 0.48) in winter. The high variability in these estimates is probably a result of the topography of the landscape and the biology of the species. We discuss the potential application of distance sampling with camera traps to estimate the density of mountain ungulates in remote and rugged terrain, and the limitations of this method.Publisher PDFPeer reviewe
Wunderlich--Herlyn--Werner syndrome
A 25 year old married and nulliparous woman with regular menstrual cycles presented with dyspareunia, infertility, increasing dysmenorrhea and recent onset vulval swelling in the gynaec outpatient department at Bhaskar medical college & Bhaskar General Hospital, Moinabad, Telangana. Gynaecological examination, ultrasound, MRI & laparoscopy helped in the diagnosis of right hematometrocolpos with noncommunicating right hemivagina,uterus didelphys with absent right kidney and right ureter commonly named as Wunderlich--Herlyn--Werner syndrome or Obstructed Hemivagina with Ipsilateral Renal Agenesis(OHVIRA) syndrome. Left half of uterus, cervix , vagina along with left kidney and ureter were normal. Vaginal septal resection was done draining out the hematometrocolpos and patient’s symptoms were relieved. It also improved the chances for fertility. Wunderlich -Herlyn--Werner syndrome or Obstructed Hemivagina and ipsilateral renal agenesis (OHVIRA syndrome) is a rare mullerian anomaly.
Glass fiber reinforced ultra-high strength concrete with silica fume
Konvencionalni beton pojačan staklenim vlaknima (GFRC) ima široku primjenu u visokim zgradama, mostovima i radovima obnove. U ovom istraživanju razvijene su mješavine betona pojačanog staklenim vlaknima ultravisoke čvrstoće kako bi se smanjila veličina nosivih elemenata. Varijacija postotka staklenih vlakana bila je 0 %, 0,03 %, 0,06 %, 0,09 % i 0,12 %. U ovom istraživanju izrađeno je i ispitano deset greda, s dva omjera raspona i statičke visine (a/d) od 1,6 i 2. Svi testirani uzorci opterećeni su do sloma, no vrijednosti čvrstoće su varirale. Točnije, uzorci pojačani s 0,09 i 0,06-postotnim staklenim vlaknima pokazali su najveću savojnu i posmičnu čvrstoću. Rezultati dobiveni ovim istraživanjem mogu se iskoristiti za odabir optimalnih mješavina betona ultravisoke čvrstoće pojačanog staklenim vlaknima u zadovoljavajućim radnim uvjetima.Conventional glass fiber-reinforced concrete (GFRC) has wide applications in high-rise buildings, bridges, and renovation works. In this study, ultra-high-strength glass fiber reinforced concrete (UHS-GFRC) mixtures were developed to minimize the size of the structural members. The percentage of glass fiber was varied as 0%, 0.03%, 0.06%, 0.09%, and 0.12%. In this investigation, ten beams were cast and tested, with two span-to-effective-depth (a/d) ratios of 1.6 and 2. All the tested specimens attained their respective strengths; however, the strength values varied. Specifically, the specimens reinforced with 0.09% and 0.06% of glass fiber exhibited the highest flexural and shear strengths, respectively. The results obtained in this study can be utilized to select optimum mixtures of UHS-GFRC under satisfying service conditions
Loss of genetic diversity and inbreeding in Kashmir red deer (Cervus elaphus hanglu) of Dachigam National Park, Jammu & Kashmir, India
BACKGROUND: Hangul (Cervus elaphus hanglu), the eastern most subspecies of red deer, is now confined only to the mountains in the Kashmir region of Jammu & Kashmir State of India. It is of great conservation significance as this is the last and only hope for Asiatic survivor of the red deer species in India. Wild population of free ranging hangul deer inhabiting in and around Dachigam National Park was genetically assessed in order to account for constitutive genetic attributes of hangul population using microsatellite markers. RESULTS: In a pool of 36 multi-locus genotypes, 30 unique individuals were identified based on six microsatellite loci. The estimated cumulative probability of identity assuming all individuals were siblings (P(ID) sibs) was 0.009 (9 in 1000). Altogether, 49 different alleles were observed with mean (± s.e.) allelic number of 8.17 ± 1.05, ranging from 5 to 11 per locus. The observed heterozygosity ranged between 0.08 and 0.83, with mean 0.40 ± 0.11 and the inbreeding coefficient ranged between −0.04 and 0.87 with mean 0.38 ± 0.15. Majority of loci (5/6) were found to be informative (PIC value > 0.5). All loci deviated from Hardy-Weinberg equilibrium except Ca-38 (P > 0.05) and none of the pairs of loci showed significant linkage disequilibrium except the single pair of Ca-30 and Ca-43 (P < 0.05). CONCLUSIONS: The preliminary findings revealed that hangul population is significantly inbred and exhibited a low genetic diversity in comparison to other deer populations of the world. We suggest prioritizing the potential individuals retaining high heterozygosity for ex situ conservation and genetic monitoring of the hangul population should be initiated covering the entire distribution range to ensure the long term survival of hangul. We speculate further ignoring genetics attributes may lead to a detrimental effect which can negatively influence the reproductive fitness and survivorship of the hangul population in the wild
Decreasing brown bear (Ursus arctos) habitat due to climate change in Central Asia and the Asian Highlands
Around the world, climate change has impacted many species. In this study, we used bioclimatic variables and biophysical layers of Central Asia and the Asian Highlands combined with presence data of brown bear (Ursus arctos) to understand their current distribution and predict their future distribution under the current rate of climate change. Our bioclimatic model showed that the current suitable habitat of brown bear encompasses 3,430,493 km2 in the study area, the majority of which (>65%) located in China. Our analyses demonstrated that suitable habitat will be reduced by 11% (378,861.30 km2) across Central Asia and the Asian Highlands by 2,050 due to climate change, predominantly (>90%) due to the changes in temperature and precipitation. The spatially averaged mean annual temperature of brown bear habitat is currently −1.2°C and predicted to increase to 1.6°C by 2,050. Mean annual precipitation in brown bear habitats is predicted to increase by 13% (from 406 to 459 mm) by 2,050. Such changes in two critical climatic variables may significantly affect the brown bear distribution, ethological repertoires, and physiological processes, which may increase their risk of extirpation in some areas. Approximately 32% (1,124,330 km2) of the total suitable habitat falls within protected areas, which was predicted to reduce to 1,103,912 km2 (1.8% loss) by 2,050. Future loss of suitable habitats inside the protected areas may force brown bears to move outside the protected areas thereby increasing their risk of mortality. Therefore, more protected areas should be established in the suitable brown bear habitats in future to sustain populations in this region. Furthermore, development of corridors is needed to connect habitats between protected areas of different countries in Central Asia. Such practices will facilitate climate migration and connectivity among populations and movement between and within countries
Invasive Group A Streptococcal Infection in High School Football Players, New York City, 2003
After being notified that 2 high school football teammates were hospitalized with confirmed or suspected invasive group A streptococcal infections, we conducted an investigation of possible spread among other team members. This investigation highlights a need for guidelines on management of streptococcal and other infectious disease outbreaks in team sport settings
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