On Distributed Linear Estimation With Observation Model Uncertainties

We consider distributed estimation of a Gaussian source in a heterogenous bandwidth constrained sensor network, where the source is corrupted by independent multiplicative and additive observation noises, with incomplete statistical knowledge of the multiplicative noise. For multi-bit quantizers, we derive the closed-form mean-square-error (MSE) expression for the linear minimum MSE (LMMSE) estimator at the FC. For both error-free and erroneous communication channels, we propose several rate allocation methods named as longest root to leaf path, greedy and integer relaxation to (i) minimize the MSE given a network bandwidth constraint, and (ii) minimize the required network bandwidth given a target MSE. We also derive the Bayesian Cramer-Rao lower bound (CRLB) and compare the MSE performance of our proposed methods against the CRLB. Our results corroborate that, for low power multiplicative observation noises and adequate network bandwidth, the gaps between the MSE of our proposed methods and the CRLB are negligible, while the performance of other methods like individual rate allocation and uniform is not satisfactory

On Distributed Estimation for Resource Constrained Wireless Sensor Networks

We study Distributed Estimation (DES) problem, where several agents observe a noisy version of an underlying unknown physical phenomena (which is not directly observable), and transmit a compressed version of their observations to a Fusion Center (FC), where collective data is fused to reconstruct the unknown. One of the most important applications of Wireless Sensor Networks (WSNs) is performing DES in a field to estimate an unknown signal source. In a WSN battery powered geographically distributed tiny sensors are tasked with collecting data from the field. Each sensor locally processes its noisy observation (local processing can include compression, dimension reduction, quantization, etc) and transmits the processed observation over communication channels to the FC, where the received data is used to form a global estimate of the unknown source such that the Mean Square Error (MSE) of the DES is minimized. The accuracy of DES depends on many factors such as intensity of observation noises in sensors, quantization errors in sensors, available power and bandwidth of the network, quality of communication channels between sensors and the FC, and the choice of fusion rule in the FC. Taking into account all of these contributing factors and implementing a DES system which minimizes the MSE and satisfies all constraints is a challenging task. In order to probe into different aspects of this challenging task we identify and formulate the following three problems and address them accordingly: 1- Consider an inhomogeneous WSN where the sensors\u27 observations is modeled linear with additive Gaussian noise. The communication channels between sensors and FC are orthogonal power and bandwidth-constrained erroneous wireless fading channels. The unknown to be estimated is a Gaussian vector. Sensors employ uniform multi-bit quantizers and BPSK modulation. Given this setup, we ask: what is the best fusion rule in the FC? what is the best transmit power and quantization rate (measured in bits per sensor) allocation schemes that minimize the MSE? In order to answer these questions, we derive some upper bounds on global MSE and through minimizing those bounds, we propose various resource allocation schemes for the problem, through which we investigate the effect of contributing factors on the MSE. 2- Consider an inhomogeneous WSN with an FC which is tasked with estimating a scalar Gaussian unknown. The sensors are equipped with uniform multi-bit quantizers and the communication channels are modeled as Binary Symmetric Channels (BSC). In contrast to former problem the sensors experience independent multiplicative noises (in addition to additive noise). The natural question in this scenario is: how does multiplicative noise affect the DES system performance? how does it affect the resource allocation for sensors, with respect to the case where there is no multiplicative noise? We propose a linear fusion rule in the FC and derive the associated MSE in closed-form. We propose several rate allocation schemes with different levels of complexity which minimize the MSE. Implementing the proposed schemes lets us study the effect of multiplicative noise on DES system performance and its dynamics. We also derive Bayesian Cramer-Rao Lower Bound (BCRLB) and compare the MSE performance of our porposed methods against the bound. As a dual problem we also answer the question: what is the minimum required bandwidth of the network to satisfy a predetermined target MSE? 3- Assuming the framework of Bayesian DES of a Gaussian unknown with additive and multiplicative Gaussian noises involved, we answer the following question: Can multiplicative noise improve the DES performance in any case/scenario? the answer is yes, and we call the phenomena as \u27enhancement mode\u27 of multiplicative noise. Through deriving different lower bounds, such as BCRLB,Weiss-Weinstein Bound (WWB), Hybrid CRLB (HCRLB), Nayak Bound (NB), Yatarcos Bound (YB) on MSE, we identify and characterize the scenarios that the enhancement happens. We investigate two situations where variance of multiplicative noise is known and unknown. We also compare the performance of well-known estimators with the derived bounds, to ensure practicability of the mentioned enhancement modes

Paranasal sinuses malignancies : a 12-year review of clinical characteristics

Inadequate epidemiologic investigations of the paranasal sinuses malignancies prompted this retrospective study with special emphasis on a major group of 111 tumors. Clinical records of 111 patients with histologically confirmed malignant tumors of the paranasal sinuses were investigated retrospectively from April 2000 to January 2012. Collection of data included demographic information, clinical manifestations, treatment plans, and histopathology of the tumor. There were 69 (62.16%) male and 42 (37.83%) female patients (male-to-female ratio of 1.6:1), with a median age of 49±12.2 years (range 21 to 88 years). A high level of occurrence was noticed in the fifth (26.3%) decade of life. The most frequent histological types were squamous cell carcinoma (43.5%) and adenoid cystic carcinoma (19%). Among clinical manifestations, nasal obstruction was the most frequent followed by diplopia, and facial swelling. Fifty three patients (47.74%) were treated with combined approach of surgery and radiation therapy. Paranasal sinuses malignancies are rare conditions with nonspecific symptoms which make early diagnosis of the lesions more challenging. The optimal therapeutic protocol for patients suffering from these tumors is still a somewhat controversial entity and requires further studies

Multimorbidity as an important issue among women: results of gender difference investigation in a large population-based cross-sectional study in West Asia

Objectives: To investigate the impact of gender on multimorbidity in northern Iran. Design: A cross-sectional analysis of the Golestan cohort data. Setting: Golestan Province, Iran. Study population: 49 946 residents (age 40–75 years) of Golestan Province, Iran. Main outcome measures: Researchers collected data related to multimorbidity, defined as co-existence of two or more chronic diseases in an individual, at the beginning of a representative cohort study which recruited its participants from 2004 to 2008. The researchers utilised simple and multiple Poisson regression models with robust variances to examine the simultaneous effects of multiple factors. Results: Women had a 25.0% prevalence of multimorbidity, whereas men had a 13.4% prevalence (p<0.001). Women of all age-groups had a higher prevalence of multimorbidity. Of note, multimorbidity began at a lower age (40–49 years) in women (17.3%) compared with men (8.6%) of the same age (p<0.001). This study identified significant interactions between gender as well as socioeconomic status, ethnicity, physical activity, marital status, education level and smoking (p<0.01). Conclusion: Prevention and control of multimorbidity requires health promotion programmes to increase public awareness about the modifiable risk factors, particularly among women

Low Level Laser Irradiation Effects on Proliferation and Apoptosis in Bone Marrow Mesenchymal Stem Cells

Low level laser irradiationis an effective method in treating some diseases and it could improve regeneration and wound healing. Some studies have reported that low level laser irradiation could enhance proliferation by increasing ATP level in the cells mitochondria.Mesenchymal stem cells (MSCs) are a kind of stem cells which are capable of differentiating to other cells. Nowadays, MSCs are an appropriate option for regenerative medicine. In this study we want to investigate the optimum protocol for using low level laser irradiation to improve proliferation and make less apoptosis in Mesenchymal stem cells. The Mesenchymal stem cells were isolated from femur and tibia of a male rat and cultured in culture media. The isolated cells were differentiated to adipocyte and osteocyte to confirm their multi potency. The cells were irradiated with different exposure protocols of 808 nm diode laser. After exposure the stem cells markers (CD90, CD44 and CD45), doubling time, colony forming frequency and Caspase 3 activity (for apoptosis evaluation) were assessed.Both 640 mW (8th group) and 830 mW (14th group) have best result in colony forming and doubling time; however the 8th group had the least Caspase 3 activity. The patterns of stem cells markers expression have not changed after laser irradiation.The protocol used in 8th group could improve Mesenchymal stem cells proliferation more than the rest protocols and also it might make the apoptosis less than the other group. This irradiation protocol could be useful in regenerative medicine due to its effects on Mesenchymal stem cells

Low Level Laser Irradiation Effects on Proliferation and Apoptosis in Bone Marrow Mesenchymal Stem Cells

Low level laser irradiationis an effective method in treating some diseases and it could improve regeneration and wound healing. Some studies have reported that low level laser irradiation could enhance proliferation by increasing ATP level in the cells mitochondria.Mesenchymal stem cells (MSCs) are a kind of stem cells which are capable of differentiating to other cells. Nowadays, MSCs are an appropriate option for regenerative medicine. In this study we want to investigate the optimum protocol for using low level laser irradiation to improve proliferation and make less apoptosis in Mesenchymal stem cells. The Mesenchymal stem cells were isolated from femur and tibia of a male rat and cultured in culture media. The isolated cells were differentiated to adipocyte and osteocyte to confirm their multi potency. The cells were irradiated with different exposure protocols of 808 nm diode laser. After exposure the stem cells markers (CD90, CD44 and CD45), doubling time, colony forming frequency and Caspase 3 activity (for apoptosis evaluation) were assessed.Both 640 mW (8th group) and 830 mW (14th group) have best result in colony forming and doubling time; however the 8th group had the least Caspase 3 activity. The patterns of stem cells markers expression have not changed after laser irradiation.The protocol used in 8th group could improve Mesenchymal stem cells proliferation more than the rest protocols and also it might make the apoptosis less than the other group. This irradiation protocol could be useful in regenerative medicine due to its effects on Mesenchymal stem cells

Molecular docking evaluation of celecoxib on the boron nitride nanostructures for alleviation of cardiovascular risk and inflammatory

Celecoxib (CXB) is a nonsteroidal anti-inflammatory drug (NSAID) that can be used to treat rheumatoid arthritis and ischemic heart disease. In this research, density functional theory (DFT) and molecular docking simulations were performed to study the interaction of boron nitride nanotube (BNNT) and boron nitride nanosheet (BNNS) with CXB and its inhibitor effect on pro-inflammatory cytokines. The calculated adsorption energies of CXB with the BNNT were determined in aqueous phase. The results revealed that adsorption of CXB molecule via its SO2 group on BNNT is thermodynamically favored than the NH2 and CF3 groups in the solvent environment. Adsorption of CXB on BN nanomaterials are weak physisorption in nature. This can be attributed to the fact that both phenyl groups in CXB are not on the same plane and require significant activation energies for conformational changes to obtain greater H-π interaction. Both BNNT and BNNS materials had huge sensitivity in electronic change and short recovery time during CXB interaction, thus having potential as molecular sensor and biomedical carrier for the delivery of CXB drug. IL-1A and TNF-α were implicated as vital cytokines in diverse diseases, and they have been a validated therapeutic target to manage cardiovascular risk in patients with inflammatory bowel disease. A molecular docking simulation confirms that the BNNT loaded CXB could inhibit more pro-inflammatory cytokines including IL-1A and TNF-α receptors as compared to BNNS loaded to CXB