Assessment of Uncertainty in Volume Estimation of Non-Static Target: A Phantom Study using Racemosa Wood.

INTRODUCTION: CT information of the target undergoing motion/movement during its scanning has been questioned by many researchers for its preciseness as well as accuracy. The present study was taken with aim to validate the racimosa wood as lung equivalent and to assess the uncertainty in volume estimation during virtual simulation of non-static target of known dimension such as in lung cancer radiotherapy. MATERIALS AND METHODS: The racemosa wood was validated as lung equivalent material with the help of two methods. Wood insert with tumor model was put into the hollow cylinder space of dimension 6.4 cm in diameter provided in CIRS phantom. First CT image of rest position was taken and given name "No Movement". Subsequently the tumor was shifted +/-5mm, +/-15mm and +/-25 mm with respect to "Rest Position". CT images of the CIRS phantom containing tumor in wood cylinder were acquired after each movement given to wood cylinder. RESULTS: The relative electron density of racemosa wood corresponding to HU value -724 was found to be 0.275 gm/cm3. The true volume of the target was 7.8.cm3 however variation up to 9.5 cm3 was observed in CT produced volume of the target over the range of different movements. DISCUSSION: The racemosa wood was found to be having range of density (- 850 HU to - 400 HU) similar to real human lung density variation. Various studies have been performed using uniform density lung structures in their experimental setups to assess the accuracy in lung cancer radiation delivery. However, in the present work approximately real clinical setting was reproduced by putting the wood cylinder with density variation from 0.2 gm/cm3- 4.5 gm/cm3in hollow space provided in one lung structure the phantom used in this study. CONCLUSIONS: The racemosa wood was found to be lung equivalent which is available locally and cost-effective as well. Overestimation in the target volume (by CT imaging) showed a trend of increase with 3 directional movement amplitudes. The results of this study can be utilised in lung cancer radiotherapy as the same were derived from setup having clinical settings in terms of lung density variation, shape, compositions of the phantom maximally as found during the real patient radiotherapy.

Machine Learning in Differentiating Gliomas from Primary CNS Lymphomas: A Systematic Review, Reporting Quality, and Risk of Bias Assessment.

BACKGROUND: Differentiating gliomas and primary CNS lymphoma represents a diagnostic challenge with important therapeutic ramifications. Biopsy is the preferred method of diagnosis, while MR imaging in conjunction with machine learning has shown promising results in differentiating these tumors. PURPOSE: Our aim was to evaluate the quality of reporting and risk of bias, assess data bases with which the machine learning classification algorithms were developed, the algorithms themselves, and their performance. DATA SOURCES: Ovid EMBASE, Ovid MEDLINE, Cochrane Central Register of Controlled Trials, and the Web of Science Core Collection were searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. STUDY SELECTION: From 11,727 studies, 23 peer-reviewed studies used machine learning to differentiate primary CNS lymphoma from gliomas in 2276 patients. DATA ANALYSIS: Characteristics of data sets and machine learning algorithms were extracted. A meta-analysis on a subset of studies was performed. Reporting quality and risk of bias were assessed using the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) and Prediction Model Study Risk Of Bias Assessment Tool. DATA SYNTHESIS: The highest area under the receiver operating characteristic curve (0.961) and accuracy (91.2%) in external validation were achieved by logistic regression and support vector machines models using conventional radiomic features. Meta-analysis of machine learning classifiers using these features yielded a mean area under the receiver operating characteristic curve of 0.944 (95% CI, 0.898-0.99). The median TRIPOD score was 51.7%. The risk of bias was high for 16 studies. LIMITATIONS: Exclusion of abstracts decreased the sensitivity in evaluating all published studies. Meta-analysis had high heterogeneity. CONCLUSIONS: Machine learning-based methods of differentiating primary CNS lymphoma from gliomas have shown great potential, but most studies lack large, balanced data sets and external validation. Assessment of the studies identified multiple deficiencies in reporting quality and risk of bias. These factors reduce the generalizability and reproducibility of the findings.

Feasibility of measuring psychological resilience in hospitalized patients with acute illness: The Resilience After the Trauma of Acute Illness (RAFT) study.

Resilience is the 'ability to bounce back'. We want to investigate whether measurement of resilience during an acute hospital admission is feasible. We conducted a feasibility study. Resilience was measured using the Brief Resilience Scale. Results were contextualized by measuring chronic disease burden, anxiety, depression, coping strategies and personality traits. 56 or 103 patients approached took part in the study. A group of 12 patients undergoing pulmonary rehabilitation served as a control group. We found evidence of low resilience in 4/44 (9%) patients admitted as medical emergencies. Low resilience was statistically related to the Hospital Anxiety and Depression Scale and a number of coping strategies and personality traits. We found no relation between measures of resilience and previous admissions to hospital. The concept of resilience might be applicable to unscheduled admissions to hospital. Larger studies are required to establish whether low resilience is common and amenable to intervention. REC number 17/WA/0024.

Evaluation of Lung Density and Its Dosimetric Impact on Lung Cancer Radiotherapy: A Simulation Study.

BACKGROUND: The dosimetric parameters required in lung cancer radiation therapy are taken from a homogeneous water phantom; however, during treatment, the expected results are being affected because of its inhomogeneity. Therefore, it becomes necessary to quantify these deviations. OBJECTIVE: The present study has been undertaken to find out inter- and intra- lung density variations and its dosimetric impact on lung cancer radiotherapy using Monte Carlo code FLUKA and PBC algorithms. MATERIAL AND METHODS: Density of 100 lungs was recorded from their CT images along with age. Then, after PDD calculated by FLUKA MC Code and PBC algorithm for virtual phantom having density 0.2 gm/cm3 and 0.4 gm/cm3 (density range obtained from CT images of 100 lungs) using Co-60 10 x10 cm2 beams were compared. RESULTS: Average left and right lung densities were 0.275±0.387 and 0.270±0.383 respectively. The deviation in PBC calculated PDD were (+)216%, (+91%), (+)45%, (+)26.88%, (+)14%, (-)1%, (+)2%, (-)0.4%, (-)1%, (+)1%, (+)4%, (+)4.5% for 0.4 gm/cm3 and (+)311%, (+)177%, (+)118%, (+)90.95%, (+)72.23%, (+)55.83% ,(+)38.85%, (+)28.80%, (+)21.79%, (+)15.95%, (+)1.67%, (-) 2.13%, (+)1.27%, (+)0.35%, (-)1.79%, (-)2.75% for 0.2 gm/cm3 density mediums at depths of 1mm, 2mm, 3mm, 4mm, 5mm, 6 mm, 7 mm, 8mm, 9mm,10mm, 15mm, 30mm, 40mm, 50mm, 80mm and 100 mm, respectively. CONCLUSION: Large variations in inter- and intra- lung density were recorded. PBC overestimated the dose at air/lung interface as well as inside lung. The results of Monte Carlo simulation can be used to assess the performance of other treatment planning systems used in lung cancer radiotherapy.

Validation of the Gel & Wax Boluses and Comparison of their Dosimetric Performance with Virtual Bolus.

BACKGROUND: In general, radiotherapy treatment planning is performed using the virtual bolus. It is necessary to investigate physical bolus in comparison to virtual one. OBJECTIVES: In the present study, first, radiological properties of superflab Gel bolus and Paraffin wax bolus was investigated in terms of their relative electron density. Then, dosimetric performance of both the bolus (i.e. Gel and Parafin wax) was compared with Virtual bolus. MATERIAL AND METHODS: In This experimental study, the radiological property of Wax and Gel boluses was investigated using two methods. In one, the relative electron density of both the Gel and Wax boluses was calculated by measuring their linear attenuation coefficient where in another method relative electron density was calculated by recording their CT No directly from their CT scan. Later CT scan of solid water slab phantom (dimension 30x30x15 cm3), with physical boluses (i.e. Gel and Wax bolus) of appropriate thicknesses required to deliver a dose of 200 cGy at Dmax using 4 MV, 6 MV and 15 MV photon beams, was taken. These CT data sets were retrieved to TPS. A plan was done to deliver a dose of 200 cGy at Dmax using Single 4 MV, 6 MV and 15 MV photon beams. Dose at depths Dmax, 1 cm, 2 cm, 3 cm, 4 cm and 5 cm was recorded. Using this similar method, doses at depths viz Dmax, 1 cm, 2 cm, 3 cm, 4 cm and 5 cm was recorded for the Gel and Wax boluses. The differences in dose of gel and wax bolus from virtual bolus were recorded for comparison of their dosimetric performance. RESULTS: The measured (calculated) relative electron density of wax and Gel bolus was found to be 0.958 (0.926) and 0.923 (0.907), respectively. Variation in dosimetric performance of Gel and Wax with reference to Virtual bolus was studied. However, on average, Gel bolus was more consistent with virtual bolus. CONCLUSION: To avoid any dose difference between, delivered (using physical bolus) and planned (using virtual bolus), the physical boluses should be investigated for their dosimetric performance in comparison to virtual bolus. The results obtained and methodology used in this study can be applied in routine radiotherapy practices.

Evaluation of AAA and XVMC Algorithms for Dose Calculation in Lung Equivalent Heterogeneity in Photon Fields: A Comparison of Calculated Results with Measurements.

AIMS: The aims of the present work are (1) to evaluate dose calculation accuracy of two commonly used algorithms for 15 MV small photon fields in a medium encompassing heterogeneity and (2) to compare them with measured results obtained from gafchromic film EBT2. MATERIALS AND METHODS: Authors employed kailwood (Pinus Wallichiana) to mimic lung. Briefly, seven Kailwood plates, each measuring 25x25 cm2 of varying thicknesses totaling 13 cm equivalent to the mean thickness of an adult human lung, were sandwiched between 5 cm tissue equivalent material from top and 10 cm below. Physical measurements were performed using Radiochromic film EBT2. The field sizes of 1x1, 2x2, 5x5 and 10x10 cm2 were selected at 100 cm SSD. Simulations were performed using EGSnrc/DOSRZnrc Monte Carlo code. The dose variation inside the inhomogeneity and near the interface was calculated using AAA & XVMC algorithm. RESULTS: Preliminary results show that there is large variation of dose inside inhomogeneity. The maximum variation of dose inside the inhomogeneity for 1x1 cm2 was found 40% by AAA and 4.5% by XVMC compared to measured/simulated results. For the field size of 2x2 cm2, these figures were 27% by AAA & 3.5% by XVMC. For 5x5 cm2 field size, the variation is small which becomes insignificant for larger fields. CONCLUSION: The results presented in this work indicate that for smaller fields, XVMC algorithm gives more realistic prediction, while there is the need for caution on using AAA algorithm for dose calculations involving small area irradiation encompassing heterogeneities and low-density media.

Association of Relationship between Periodontal Disease and Cardiovascular Disease.

The present study was undertaken to determine the relationship between periodontal and cardiovascular disease. Previous studies have shown some co-relation between the two conditions. We included 186 patients divided into four groups. First two Groups (A1 & A2) were the patients with cardiac disease (100 in numbers) whilst Groups (B1 & B2) (86 in numbers) were treated as controls (without cardiac disease). Following markers of periodontal disease were assessed - plaque index, calculus index, gingival and periodontal index. Markers of cardiovascular disease included were LDL, HDL, total cholesterol and CRP. Ramfjords periodontal index was used to assess the extent of periodontal disease. In the present study there was a significant increase in CRP levels in Group A1 (CVD + PD) compared to controls and overall the two cardiac groups showed a significant increase in CRP compared to controls. There was a non-significant change in lipid profile markers (LDL, HDL and total cholesterol). Periodontal Disease Index (PDI) was also increased in Group A1 compared to other groups except Group B1 and overall in cardiac groups compared to non-cardiac (PD) groups. In this study no correlation between periodontal and cardiovascular disease was found. This may be due intake of statins by few patients in Group A with a confirmed diagnosis of cardiovascular disease.

Unusual presentation of chondroblastoma mimicking Trevor's disease.

Chondroblastoma is a benign bone tumor, represents 1%-2% of all primary bone tumors, typically seen in patients 10-25-year-old and more common in males. It occurs most frequently in the distal femur, proximal tibia, and proximal humerus. Soft tissue extension is extremely rare. Adjacent joints may develop effusions, but the tumor mass protruding into the joint has never been seen in case of chondroblastoma. We report a rare case of intra-articular chondroblastoma arising from proximal tibia in a 16-year-old boy and growing into the knee joint mimicking an intra-articular osteochondroma.

Performance Evaluation of Algorithms in Lung IMRT: A comparison of Monte Carlo, Pencil Beam, Superposition, Fast Superposition and Convolution Algorithms.

BACKGROUND: Inclusion of inhomogeneity corrections in intensity modulated small fields always makes conformal irradiation of lung tumor very complicated in accurate dose delivery. OBJECTIVE: In the present study, the performance of five algorithms via Monte Carlo, Pencil Beam, Convolution, Fast Superposition and Superposition were evaluated in lung cancer Intensity Modulated Radiotherapy planning. MATERIALS AND METHODS: Treatment plans for ten lung cancer patients previously planned on Monte Carlo algorithm were re-planned using same treatment planning indices (gantry angel, rank, power etc.) in other four algorithms. RESULTS: The values of radiotherapy planning parameters such as Mean dose, volume of 95% isodose line, Conformity Index, Homogeneity Index for target, Maximum dose, Mean dose; %Volume receiving 20Gy or more by contralateral lung; % volume receiving 30 Gy or more; % volume receiving 25 Gy or more, Mean dose received by heart; %volume receiving 35Gy or more; %volume receiving 50Gy or more, Mean dose to Easophagous; % Volume receiving 45Gy or more, Maximum dose received by Spinal cord and Total monitor unit, Volume of 50 % isodose lines were recorded for all ten patients. Performance of different algorithms was also evaluated statistically. CONCLUSION: MC and PB algorithms found better as for tumor coverage, dose distribution homogeneity in Planning Target Volume and minimal dose to organ at risks are concerned. Superposition algorithms found to be better than convolution and fast superposition. In the case of tumors located centrally, it is recommended to use Monte Carlo algorithms for the optimal use of radiotherapy.

Emergence of core-peripheries in networks.

A number of important transport networks, such as the airline and trade networks of the world, exhibit a characteristic core-periphery structure, wherein a few nodes are highly interconnected and the rest of the network frays into a tree. Mechanisms underlying the emergence of core-peripheries, however, remain elusive. Here, we demonstrate that a simple pruning process based on removal of underutilized links and redistribution of loads can lead to the emergence of core-peripheries. Links are assumed beneficial if they either carry a sufficiently large load or are essential for global connectivity. This incentivized redistribution process is controlled by a single parameter, which balances connectivity and profit. The obtained networks exhibit a highly resilient and connected core with a frayed periphery. The balanced network shows a higher resilience than the world airline network or the world trade network, revealing a pathway towards robust structural features through pruning.

Accumulation of Metals in Soils, Groundwater and Edible Parts of Crops Grown Under Long-Term Irrigation with Sewage Mixed Industrial Effluents.

Farmers in developing countries irrigate crops using raw urban and industrial effluents with consequent risks from metal contamination. Therefore, soils, crops and groundwater from an effluent irrigation use site were assessed for Cd, Cr, Ni and Pb. Total and available contents of metals in soil followed the order Pb>Ni>Cr>Cd. Crops accumulated more Pb, followed by Cd, Ni and Cr. Pb exceeded the permissible limit with wastewater irrigation only, but Cd exceeded the limit even with combined irrigations of wastewater and groundwater. Among crops, sugar beet assimilated highest Cd (3.14 µg g(-1)) and Pb (6.42 µg g(-1)) concentrations. Legumes accumulated more metals than cereals. Long-term use of wastewater and its conjunctive use with groundwater led to toxic accumulations of Cd, Pb, Ni and Cr. Cd with higher availability and mobility indices and lower toxicity limit, posed the maximum risk of food-chain contamination.

Revealing the structure of the world airline network.

Resilience of most critical infrastructures against failure of elements that appear insignificant is usually taken for granted. The World Airline Network (WAN) is an infrastructure that reduces the geographical gap between societies, both small and large, and brings forth economic gains. With the extensive use of a publicly maintained data set that contains information about airports and alternative connections between these airports, we empirically reveal that the WAN is a redundant and resilient network for long distance air travel, but otherwise breaks down completely due to removal of short and apparently insignificant connections. These short range connections with moderate number of passengers and alternate flights are the connections that keep remote parts of the world accessible. It is surprising, insofar as there exists a highly resilient and strongly connected core consisting of a small fraction of airports (around 2.3%) together with an extremely fragile star-like periphery. Yet, in spite of their relevance, more than 90% of the world airports are still interconnected upon removal of this core. With standard and unconventional removal measures we compare both empirical and topological perceptions for the fragmentation of the world. We identify how the WAN is organized into different classes of clusters based on the physical proximity of airports and analyze the consequence of this fragmentation.

Improvement in thermostability of metagenomic GH11 endoxylanase (Mxyl) by site-directed mutagenesis and its applicability in paper pulp bleaching process.

An attempt has been made for enhancing the thermostability of xylanase (Mxyl) retrieved from a compost-soil-based metagenomic library. The analysis of the structure of xylanase by molecular dynamics simulation revealed more structural fluctuations in ß-sheets. When the surface of ß-sheets was enriched with arginine residues by substituting serine/threonine by site-directed mutagenesis, the enzyme with four arginine substitutions (MxylM4) exhibited enhanced thermostability at 80 °C. The T 1/2 of MxylM4 at 80 °C, in the presence of birchwood xylan, increased from 130 to 150 min at 80 °C without any alteration in optimum pH and temperature and molecular mass. Improvement in thermostability of MxylM4 was corroborated by increase in T m by 6 °C over that of Mxyl. The K m of MxylM4, however, increased from 8.01 ± 0.56 of Mxyl to 12.5 ± 0.32 mg ml(-1), suggesting a decrease in the affinity as well as specific enzyme activity. The Mxyl as well as MxylM4 liberated chromophores and lignin-derived compounds from kraft pulp, indicating their applicability in pulp bleaching.

Genetic correlation between chromium resistance and reduction in Bacillus brevis isolated from tannery effluent.

AIMS: To investigate the genetic basis of Cr(VI) resistance and its reduction to Cr(III) in indigenous bacteria isolated from tannery effluent. METHODS AND RESULTS: Four bacteria resistant to high Cr(VI) levels were isolated and identified as Bacillus spp. Their Cr(VI) reduction ability was tested. To assess the genetic basis of Cr(VI) resistance and reduction, plasmid transfer and curing studies were performed. Among all, B. brevis was resistant to 180 microg Cr(VI) ml(-1) and showed the greatest degree of Cr(VI) reduction (75.8%) within 28 h and its transformant was resistant to 160 microg Cr(VI) ml(-1) and reduced 69.9% chromate. It harboured a stable 18 kb plasmid DNA. Transfer and curing studies revealed that both the chromate resistance and reduction were plasmid mediated. The presence of other metal cations did not have any significant effect on Cr(VI) bioreduction. CONCLUSIONS: Bacillus brevis was resistant to elevated Cr(VI) levels and may potentially reduce it in short time from an environment where other metal ions are also present in addition to chromium ions. The strain tested shows a positive correlation between genetic basis of Cr(VI) resistance and reduction. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first study on the genetic correlation between chromium resistance and reduction in bacteria. Such strains may potentially be useful in biotechnological applications and in situ Cr(VI) bioremediation.

Prevalence and risk factors associated with worm infestation in pre-school children (6-23 months) in selected blocks of Uttar Pradesh and Jharkhand, India.

BACKGROUND: Intestinal worm infestation is widely prevalent in developing countries and can result in impaired nutrition and development. AIMS: To estimate prevalence of and risk factors for intestinal geohelminths and other intestinal parasites in children aged 6 to 23 months. SETTINGS AND DESIGN: Cross sectional study in rural India. MATERIALS AND METHODS: Proportionate population size sampling method was used to randomly select 15 villages per block. Thereafter, house-to-house survey was done to recruit eligible children and obtain fecal sample for microbiological examination. STATISTICAL ANALYSIS: Univariate distribution of variables was assessed and comparison between categorical variables and continuous variables was done using a Chi-square test and student's t-test, respectively. Odds ratio was calculated to assess associations. RESULTS: Overall 926 children were recruited and 909 fecal samples examined. Combined prevalence of infestation with intestinal geohelminths treatable by albendazole and other intestinal parasites non-treatable by albendazole was 50.3% (457/909) and 51.6% (469/909), respectively. Exclusive use of hand pump water (OR = 1.79, CI = 1.36-2.35, P CONCLUSION: Since almost half the children are infected with intestinal geohelminths treatable by albendazole, targeted deworming of population in this age group should be considered.

Portrayal of health-related behaviours in popular UK television soap operas.

BACKGROUND: Evidence suggests that health-related story lines in popular television programmes may lead to increased viewer knowledge or behaviour change. However, little is currently known about the portrayal of common health-related behaviours on UK television soap operas. METHODS: The portrayal of 11 key health-related behaviours on the 4 most popular soap operas set and broadcast in the UK over 4 weeks in spring 2005 was assessed. RESULTS: Seven of the 11 behaviours of interest were recorded a total of 959 times during 32 h of programming (or 30 behaviours per programming hour). The behaviour most frequently recorded was alcohol-related behaviours, recorded 619 times (19.3 per programming hour). No instances of four behaviours of interest were observed: driving soon after drinking, drinking during pregnancy, smoking during pregnancy or smoking around children. CONCLUSIONS: Popular television serials offer the chance to portray "healthy" behaviours as normal, and so help change attitudes and shape behavioural norms among the viewing public. Engaging the makers of these programmes in a health promotion agenda may be a fruitful method of promoting healthy behaviours.

Chromium (VI) biosorption and bioaccumulation by chromate resistant bacteria.

In this study, strains that are capable of bioaccumulating Cr(VI) were isolated from treated tannery effluent of a common effluent treatment plant. The Cr(VI) concentration in this treated effluent was 0.96 mg/l, much above the statutory limit of 0.1 mg/l for discharge of industrial effluents into inland surface waters in India. In addition to the bioaccumulation, biosorption capabilities of living and dead cells were analysed. Two strains, identified as Bacillus circulans and Bacillus megaterium were able to bioaccumulate 34.5 and 32.0 mg Cr/g dry weight, respectively and brought the residual concentration of Cr(VI) to the permissible limit in 24 h when the initial concentration was 50 mg Cr(VI)/l. Our experimental design accounts for initial as well as final residual concentration of heavy metal while selecting heavy metal accumulating strains during batch studies. Biosorption of Cr(VI) was shown by B. megaterium and an another strain, B. coagulans. Living and dead cells of B. coagulans biosorbed 23.8 and 39.9 mg Cr/g dry weight, respectively, whereas, 15.7 and 30.7 mg Cr/g dry weight was biosorbed by living and dead cells of B. megaterium, respectively. Biosorption by the dead cells was higher than the living cells. This was due to prior pH conditioning (pH 2.5 with deionized water acidified with H2SO4) of the dead cells.

Chromate tolerant bacteria isolated from tannery effluent.

The occurrence of metal tolerant and antibiotic resistant organisms was investigated in tannery effluent. Seventy-seven isolates comprising heterotrophs (41) and coliforms (36) which were tolerant to chromate level of > 50 microg/ml were selected for detailed study. The majority of the coliforms were resistant to higher levels of chromate (200 microg/ml) whereas around 3% of the heterotrophs were resistant to Cr6+ at a level of > 150 microg/ml. All chromate tolerant heterotrophs were also tolerant to Cu2+ (100%) whereas only 58.53% coliforms were tolerant to Cu2+. Except in the case of Cd2+ a higher number of heterotrophs were found tolerant to other heavy metals tested. Both groups of isolates were found sensitive to mercury. Resistance to cephaloridine was more abundant (P < 0.001) in coliforms as compared to heterotrophs. On the other hand a significantly higher number (P < 0.01) of heterotrophs showed resistance to streptomycin and carbencillin. All coliforms were sensitive to chloramphenicol. Around 80%) and 31.70% of coliforms and heterotrophs exhibited a relationship to the combination of metals and antibiotics. Both heterotrophs and coliforms tolerant to Hg2+ were also resistant to polymixin-B.