K–partitioning of Signed or Weighted Bipartite Graphs

Abstract — In this work, K-partitioning of signed or weighted bipartite graph problem has been introduced, which appears as a real life problem where the partitions of bipartite graph represent two different entities and the edges between the nodes of the partitions represent the relationships among them. A typical example is the set of people and their opinions, whose strength is represented as signed numerical values. Using the weights on the edges, these bipartite graphs can be partitioned into two or more clusters. In political domain, a cluster represents strong relationship among a group of people and a group of issues. In the paper, we formally define the problem and compare different heuristics, and show through both real and simulated data the effectiveness of our approaches

Thermal performance and pressure drop of different pin-fin geometries

The purpose of this study is to show the performance of hexagonal, square and cylindrical pin-fin arrays in improving heat transfer. In the present study, the thermal performance and pressure drop of the pin-fin heat exchanger are studied. The heat exchanger consists of cylindrical, hexagonal and square pin-fins. These types of pin-fins are capable of producing beneficial effects in transport enhancement and flow control. The pin-fins were arranged in an in-line manner. The relative longitudinal pitch SL/D=2 , and the relative transverse pitch were kept constant ST/D=2 . Air and water are used as working fluids in shell side and tube side, respectively. The inlet temperatures of air are between 50 and 90° C. The cold water entering the heat exchanger at the inner channel flows across the fin and flows out at the inner channel. Such pin-fins show potential for enhancing the heat transfer rate in pin-fin cross flow heat exchanger

Left ventricular non-compaction in children and adolescents: Clinical features, treatment and follow-up

Background: Left ventricular non-compaction (LVNC) is a specific cardiomyopathy that occurs following a disruption of endomyocardial morphogenesis. This study presents clinical findings, diagnostic features, treatment and follow-up of pediatric patients diagnosed with LVNC. Methods: Patients with LVNC who were followed from January 2006 to March 2010 were included in this study. Diagnosis was made with the use of characteristic findings of magnetic resonance imaging and echocardiography. Holter electrocardiography and metabolic screening tests were also performed in all patients. Results: A total of 24 patients were studied (18 male, six female). Patient age at diagnosis was 50 ± 60 months (eight days to 15 years). Average follow-up period was 22 ± 12 months (four months to four years). Findings at diagnosis were as follows: eight (33%) patients had heart failure, five (20%) had rhythm abnormalities, five (20%) had cardiomegaly, two had murmurs, two had cyanosis, and two presented with fatigue. Ten (41%) patients had been followed previously with other diagnoses. In 21 (87.5%) patients, electrocardiographic abnormalities were noted, especially left ventricular hypertrophy and ST-T changes. Patients had an average ejection fraction of 46% (18-73%) and three of them had additional congenital heart disease (patent ductus arteriosus, aortopulmonary window and complex cyanotic heart disease). Scanning for metabolic diseases revealed fatty acid oxidation disorder in one patient, and mitochondrial disease in another. During follow-up, a permanent pacemaker was implanted in a patient with severe bradycardia and ventricular dysfunction, and three patients died. Conclusion: LVNC can be diagnosed at any age from newborn to adolescent and has a variable clinical course. Closer study of patients with cardiomegaly and heart failure can reduce delays in diagnosis of LVNC. (Cardiol J 2011; 18, 2: 176-184

ABCC5 supports osteoclast formation and promotes breast cancer metastasis to bone

INTRODUCTION: Bone is the most common site of breast cancer metastasis, and complications associated with bone metastases can lead to a significantly decreased patient quality of life. Thus, it is essential to gain a better understanding of the molecular mechanisms that underlie the emergence and growth of breast cancer skeletal metastases. METHODS: To search for novel molecular mediators that influence breast cancer bone metastasis, we generated gene-expression profiles from laser-capture microdissected trephine biopsies of both breast cancer bone metastases and independent primary breast tumors that metastasized to bone. Bioinformatics analysis identified genes that are differentially expressed in breast cancer bone metastases compared with primary, bone-metastatic breast tumors. RESULTS: ABCC5, an ATP-dependent transporter, was found to be overexpressed in breast cancer osseous metastases relative to primary breast tumors. In addition, ABCC5 was significantly upregulated in human and mouse breast cancer cell lines with high bone-metastatic potential. Stable knockdown of ABCC5 substantially reduced bone metastatic burden and osteolytic bone destruction in mice. The decrease in osteolysis was further associated with diminished osteoclast numbers in vivo. Finally, conditioned media from breast cancer cells with reduced ABCC5 expression failed to induce in vitro osteoclastogenesis to the same extent as conditioned media from breast cancer cells expressing ABCC5. CONCLUSIONS: Our data suggest that ABCC5 functions as a mediator of breast cancer skeletal metastasis. ABCC5 expression in breast cancer cells is important for efficient osteoclast-mediated bone resorption. Hence, ABCC5 may be a potential therapeutic target for breast cancer bone metastasis

Measurement of vertebral rotation in adolescent idiopathic scoliosis with low-dose CT in prone position - method description and reliability analysis

<p>Abstract</p> <p>Background</p> <p>To our knowledge there is no report in the literature on measurements of vertebral rotation with low-dose computed tomography (CT) in prone position.</p> <p>Aims</p> <p>To describe and test the reliability of this new method, compare it with other methods in use and evaluate the influence of body position on the degree of vertebral rotation measured by different radiological methods.</p> <p>Study design</p> <p>Retrospective study.</p> <p>Methods</p> <p>25 consecutive patients with adolescent idiopathic scoliosis scheduled for surgery (17 girls, 8 boys) aged 15 ± 2 years (mean ± SD) were included in the analysis of this study. The degree of the vertebral rotation was in all patients measured according to the method of Perdriolle on standing plain radiographs and on supine CT scanogram, and according to the method of Aaro and Dahlborn on axial CT images in prone position and on magnetic resonance imaging (MRI) in supine position. The measurements were done by one neuroradiologist at two different occasions. Bland and Altman statistical approach was used in the reliability assessment.</p> <p>Results</p> <p>The reliability of measuring vertebral rotation by axial CT images in prone position was almost perfect with an intraclass correlation coefficient of 0.95, a random error of the intraobserver differences of 2.3°, a repeatability coefficient of 3.2° and a coefficient of variation of 18.4%. Corresponding values for measurements on CT scanogram were 0.83, 5.1°, 7.2°, and 32.8%, respectively, indicating lower reliability of the latter modality and method. The degree of vertebral rotation measured on standing plain radiographs, prone CT scanogram, axial images on CT in prone position and on MRI in supine position were 25.7 ± 9.8°, 21.9 ± 8.3°, 17.4 ± 7.1°, and 16.1 ± 6.5°, respectively. The vertebral rotation measured on axial CT images in prone position was in average 7.5% larger than that measured on axial MRI in supine position.</p> <p>Conclusions</p> <p>This study has shown that measurements of vertebral rotation in prone position were more reliable on axial CT images than on CT scanogram. The measurement of vertebral rotation on CT (corrected to the pelvic tilt) in prone position imposes lower impact of the recumbent position on the vertebral rotation than did MRI in supine position. However, the magnitude of differences is of doubtful clinical significance.</p

Treatment of thoraco-lumbar curves in adolescent females affected by idiopathic scoliosis with a progressive action short brace (PASB): assessment of results according to the SRS committee on bracing and nonoperative management standardization criteria

<p>Abstract</p> <p>Background</p> <p>The effectiveness of conservative treatment of scoliosis is controversial. Some studies suggest that brace is effective in stopping curve progression, whilst others did not report such an effect.</p> <p>The purpose of the present study was to effectiveness of Progressive Action Short Brace (PASB) in the correction of thoraco-lumbar curves, in agreement with the Scoliosis Research Society (SRS) Committee on Bracing and Nonoperative Management Standardisation Criteria.</p> <p>Methods</p> <p>Fifty adolescent females (mean age 11.8 ± 0.5 years) with thoraco-lumbar curve and a pre-treatment Risser score ranging from 0 to 2 have been enrolled. The minimum duration of follow-up was 24 months (mean: 55.4 ± 44.5 months). Antero-posterior radiographs were used to estimate the curve magnitude (C_M) and the torsion of the apical vertebra (T_A) at 5 time points: beginning of treatment (t₁), one year after the beginning of treatment (t₂), intermediate time between t₁and t₄(t₃), end of weaning (t₄), 2-year minimum follow-up from t₄(t₅). Three situations were distinguished: curve correction, curve stabilisation and curve progression.</p> <p>The Kruskal Wallis and Spearman Rank Correlation tests have been used as statistical tests.</p> <p>Results</p> <p>C_Mmean value was 29,30 ± 5,16 SD at t₁and 14,67 ± 7,65 SD at t₅. T_Awas 12.70 ± 6,14 SD at t₁and 8,95 ± 5,82 at t₅. The variation between measures of Cobb and Perdriolle degrees at t_1,2,3,4,5and between C_Mt₅-t₁and T_At₅-t₁were significantly different.</p> <p>Curve correction was accomplished in 94% of patients, whereas a curve stabilisation was obtained in 6% of patients.</p> <p>Conclusion</p> <p>The PASB, due to its peculiar biomechanical action on vertebral modelling, is highly effective in correcting thoraco-lumbar curves.</p

Reproducibility of different screening classifications in ultrasonography of the newborn hip

<p>Abstract</p> <p>Background</p> <p>Ultrasonography of the hip has gained wide acceptance as a primary method for diagnosis, screening and treatment monitoring of developmental hip dysplasia in infants. The aim of the study was to examine the degree of concordance of two objective classifications of hip morphology and subjective parameters by three investigators with different levels of experience.</p> <p>Methods</p> <p>In 207 consecutive newborns (101 boys; 106 girls) the following parameters were assessed: bony roof angle (α-angle) and cartilage roof angle (β-angle) according to Graf's basic standard method, "femoral head coverage" (FHC) as described by Terjesen, shape of the bony roof and position of the cartilaginous roof. Both hips were measured twice by each investigator with a 7.5 MHz linear transducer (SONOLINE G60S^®ultrasound system, SIEMENS, Erlangen, Germany).</p> <p>Results</p> <p>Mean kappa-coefficients for the subjective parameters shape of the bony roof (0.97) and position of the cartilaginous roof (1.0) demonstrated high intra-observer reproducibility. Best results were achieved for α-angle, followed by β-angle and finally FHC. With respect to limits of agreement, inter-observer reproducibility was calculated less precisely.</p> <p>Conclusions</p> <p>Higher measurement differences were evaluated more in objective scorings. Those variations were observed by every investigator irrespective of level of experience.</p

Determination of quality of life in adolescents with idiopathic scoliosis subjected to conservative treatment.

<p>Abstract</p> <p>Introduction and objectives</p> <p>Physical deformities caused by adolescent idiopathic scoliosis (AIS) coupled with conservative treatment of AIS with orthesis unavoidably impacts on patients' quality of life (QoL). The present study aimed at evaluating the QoL in patients affected by AIS treated with brace. The study also sought to determine the ability of different QoL questionnaires to monitor QoL over the course of treatment.</p> <p>Materials and methods</p> <p>Data were collected in 108 consecutive patients (96 females, 16 males) affected by AIS admitted to the outpatient orthopaedic clinic of the Catholic University of the Sacred Heart in Rome (Italy). Patients were subjected to full-time (i.e., 22 hrs per day) conservative treatment with the progressive action short brace (PASB), the Lyon brace or a combination of PASB + Lyon brace. Three instruments were used for QoL determination: the Scoliosis Research Society 22 (SRS-22), Bad Sobernheim Stress Questionnaire (BSSQ) and the Brace Questionnaire (BrQ).</p> <p>Results</p> <p>A significant correlation was detected among the 3 scores (p < 0.001). The BrQ possesses a higher capacity to detect changes in QoL in relation to the patient gender, type of brace, curve severity at baseline and at the completion of treatment, and curve type. Overall, boys displayed a higher QoL than girls. In all 3 questionnaires, higher QoL scores were determined in patients treated with the PASB compared with those using the Lyon brace. QoL scores were significantly correlated with the curve severity. Higher QoL scores were obtained by participants with thoraco-lumbar curves as compared with those with other curves.</p> <p>Conclusions</p> <p>The 3 questionnaires are effective in capturing changes in QoL in AIS patients subjected to conservative treatment. However, the BrQ possesses a higher discriminatory capacity compared with the other questionnaires tested. PASB-based treatment is associated with better QoL than the Lyon bracing.</p