Block Diagonal Hybrid Precoding and Power Allocation for QoS-Aware BDMA Downlink Transmissions

Beam Division Multiple Access (BDMA) with hybrid precoding has recently been proposed for multi-user multiple-input multiple-output (MU-MIMO) systems by simultaneously transmitting multiple digitally precoded users' data-streams via different beams. In contrast to most existing works that assume the number of radio frequency (RF) chains must be greater than or equal to that of data-streams, this work proposes a novel BDMA downlink system by first grouping transmitting data-streams before digitally precoding data group by group. To fully harvest the benefits of this new architecture, a greedy user grouping algorithm is devised to minimize the inter-group interference while two digital precoding approaches are developed to suppress the intra-group interference by maximizing the signal-to-interference-and-noise ratio (SINR) and the signal-to-leakage-and-noise ratio (SLNR), respectively. As a result, the proposed BDMA system requires less RF chains than the total number of transmit data-streams. Furthermore, we optimize the power allocation to satisfy each user's quality of service (QoS) requirement using the D.C. (difference of convex functions) programming technique. Simulation results confirm the effectiveness of the proposed scheme.

Abstract S5-05: Impact of pre-operative exercise on breast cancer gene expression

Background: Exercise is linked to a lower risk of developing and dying from breast cancer, but the biological mechanisms through which exercise could impact breast cancer are unclear. In animal models, exercise impacts tumor formation and progression, but there are few data regarding direct effects of exercise on tumor tissue in humans. The Pre-Operative Health and Body (PreHAB) Study was a randomized window of opportunity trial designed to explore the impact of exercise on molecular pathways in women with breast cancer.

Methods: Inactive women with Stage I-III breast cancer were enrolled through Dana-Farber Cancer Institute and Yale University prior to surgery. Participants were randomized 1:1 to an aerobic and strength training exercise intervention or mind body control intervention and participated in the interventions between enrollment and the time of surgery. Tumor tissue was collected at enrollment and surgery; samples were reviewed by a breast pathologist and were macrodissected to include sections of tumor with at least 10% cellularity. Capture RNA-sequencing of the transcriptome coding regions was performed using the Illumina Truseq RNA access platform.

Results: 49 women were randomized (27 exercise and 22 control). At baseline, mean age was 52.6, BMI was 30.2kg/m2 and exercise was 49 min/wk. Mean time between enrollment and surgery was 4.2 weeks. Participants in the exercise arm significantly increased exercise vs. controls (increase of 203 vs. 23 min/wk, p<0.0001). Transcriptomic analysis was performed on the tumors from the pre and post intervention biopsies from 32 patients (16 exercise and 16 control). Quality Control analysis of the RNA-sequencing data showed an average read depth of 25 million reads per sample, mapping ∼79% to exonic regions. Principal Component Analysis revealed no read bias or batch effects and unsupervised clustering showed that pre- and post-operative samples clustered together by patient. Differential gene expression analysis by DEseq2 revealed a limited number of individual genes with significant changes after the intervention. KEGG pathway analysis, however, of 214 KEGG pathways using the bioconductor package GAGE (Generally Applicable Gene-Set Enrichment for Pathway Analysis) demonstrated upregulation of 13 unique pathways between the baseline biopsy and surgical excision in exercise participants and none in mind body participants (q<0.1). The top ranked upregulated pathway was cytokine-cytokine receptor interactions (q=6.93E-05, set size=238 genes). Il6, CCL3 and other cytokines are among the genes upregulated in this pathway. Analysis also demonstrated downregulation of 13 unique pathways (q<0.1) including cell cycle, RNA transport and DNA replication pathways, in exercise participants over the intervention period.

Conclusions: A pre-operative exercise intervention led to alterations in gene expression in tumor tissue in women with breast cancer. Validation in additional data sets and an analysis of which cellular compartments within the tumor are responsible for the changes is needed. These findings demonstrate that exercise may have a direct effect on breast tumor tissue in humans, providing new insights into the biologic mechanisms through which exercise could lower the risk of developing and dying from breast cancer.

Citation Format: Ligibel JA, Irwin M, Dillon D, Barry W, Giobbie-Hurder A, Frank E, Winer EP, McTiernan A, Cornwell M, Pun M, Brown M, Jeselsohn R. Impact of pre-operative exercise on breast cancer gene expression [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr S5-05.

Pulmonary Functions are Impaired among Carpet Factory Workers: A Spirometric Evaluation

INTRODUCTION

Carpet factory produces various types of dusts and workers occupationally get exposed to them continuously. It has adverse health effects and most notably to the pulmonary functions. Nepal is one of the carpet exporter developing countries and still does have many factories within Kathmandu valley. However, the health hazards especially the status of pulmonary function of carpet factory workers from Nepal has not been studied.

METHODS

A cross-sectional comparative study was designed to recruit carpet factory workers and healthy controls to assess their pulmonary functions. A total of 118 subjects (59 males and 59 females) were recruited (60 carpet factory workers and 58 controls). Pulmonary function tests were carried out using Medical International Research Spirolab II portable spirometer.

RESULTS

The carpet factory workers had significantly less FEV1 (90.37 ±16.6 % vs. 103.89±9.79%, p<0.001), FVC (87.78 ± 15.48 % vs. 102.81 ± 8.41 %, p < 0.001) and PEFR (66.19 ± 20.29 % vs. 102.81 ± 11.09 %, p < 0.001) as compared to control group. Similarly the carpet factory workers had significantly higher FEV1/FVC ratio (89.96 ± 6.42 % vs. 87.12 ± 4.58 %, p = 0.007) as compared to control.

CONCLUSIONS

Carpet industry dusts exposure adversely affects pulmonary functions among its workers. The findings significant increase in the FEV1/FVC ratio and decrease in FEV1, FVC, and PEFR suggest that the effects are both restrictive and obstructive patterns of lung disease.

Estimation of Physiological Cost Index as an Energy Expenditure Index using MacGregor's Equation

INTRODUCTION

Physical activity and energy expenditure can be quantified by measuring heart rate, oxygen uptake and respiratory quotient. The Physiological Cost Index (PCI) proposed by MacGregor is a simple and straightforward method to estimate the energy expenditure index. Here, we aim to estimate the energy expenditure among young Asian population using MacGregor's equation.

METHODS

A total of 50 young randomly selected healthy females performed 50m, 100m and 150m walking test at their self-selected preferred speed. The physiological cost index values for 100 m walk at speeds slower and faster than the preferred speed were also obtained. The physiological cost index during exercise was calculated using MacGregor's equation considering heart rate and speed of walking over the varying distances.

RESULTS

The PCI values on three different distances are consistent during self selected preferred speed. The PCI estimation on second and third tests for all three distances walked consistently reproducible. However for each distance walked, the first test the PCI was significantly higher than the second and third test values. The PCI values increased significantly when subjects walked either slower (p = 0.02) or faster (p = 0.001) than their normal preferred speed.

CONCLUSION

The physiological cost index values were similar for varying distances walks. The PCI was the least at the preferred speed of walking and increased when the subjects either walked slower or faster than the preferred speed. The first estimation was higher than subsequent estimations.

Snodgrass Tubularized Incised Plate Urethroplasty for Distal and Midpenile Hypospadias

Introduction: Despite hundreds of repair techniques for hypospadias, the introduction of tubularized incised plate urethroplasty (TIP) by Warren T. Snodgrass has become popular because of good functional and cosmetic outcome. The objective of this study was to share our experience of Snodgrass tubularized incised plate (TIP) urethroplasty for the repair of distal and mid-penile hypospadias. Materials and Methods: This prospective study was carried out for a period of 24 months. It included 46 male patients with the mean age of 4.1 years (18 months to 10 years). Proximal hypospadias and those distal with moderate to severe chordee were excluded. All cases underwent TIP urethroplasty as described by Snodgrass and the neourethra was covered by single or double layer of dorsal prepucial layer. The results were analyzed on the basis of duration of surgery, types of postoperative complications like urethrocutaneous fistula, meatal stenosis and wound dehiscence. Functional results assessed with ease of voiding, force and direction of urinary stream and cosmetic with external look of penis. Results: The overall complication rate requiring surgical intervention was 8 (17.3%). Mean duration of surgery was 66 minutes (60-80 minutes). Urethrocutaneous fistula occurred in 5 (10.8%), meatal stenosis in 1 (2.1%) and wound dehiscence in 2 (4.3%) patient. The cosmetic appearance was excellent in all patients involved in this study except 2 cases of wound dehiscence. All of them had vertically oriented slit like meatus with straight urinary stream. Conclusion: Tubularized incised plate urethroplasty gives good functional and excellent cosmetic results with low rate of complications in distal and mid-penile hypospadias. DOI: http://dx.doi.org/10.3126/jnps.v34i1.8692 J Nepal Paediatr Soc 2014;34(1):29-33