The wireless sensor network (WSN) signifies to a gathering of spatially spread and committed sensors for observing and logging the physical states of the environment and for organizing the information gathered at the central Base station. Many security threats may affect the functioning of these networks. Security of the data in the system depends on the cryptographic procedure and the methods where encryption and decryption keys are developed among the sensors. Symmetric key foundation is one of the best applicable ideal models for safe exchanges in WSNs. The main goal is to improve and evaluate certain issues, such as node attack, to provide better key strength, connectivity, security for node interaction, and throughput. Uniform Balanced Incomplete Block design (UBIBD) is used to generate the keys allocated by the base station to the cluster head. The cluster head distributes keys to its members using Symmetric Balanced Incomplete Block design (SBIBD), and the keys are refreshed on a regular basis to avoid out-of-date entries. In wireless sensor networks, compromised nodes can be used to inject false reports. The concept of interacting between sensor nodes using keys and establishing a secure connection aids in ensuring the network's security.

Key distribution is an important problem in wireless sensor networks where sensor nodes are randomly scattered in adversarial environments. Due to the random deployment of sensors, a list of keys must be pre-distributed to each sensor node before deployment. To establish a secure communication, two nodes must share common key from their key-rings. Otherwise, they can find a key- path in which ensures that either two neighboring nodes have a key in common from source to destination. combinatorial designs are powerful mathematical tools with comprehensive and simple structures. Recently, many researchers have used combinatorial designs as key pre-distribution scheme in wireless sensor networks. In this paper we consider a hybrid key pre-distribution scheme based on Balanced Incomplete Block design. We consider a new approach for choosing key-rings in the hybrid symmetric design to improve the connectivity and resilience. Performance and security properties of the proposed scheme are studied both analytically and computationally. The obtained results show that our scheme provides better resilience than symmetric design.

Objective: Despite advances in revascularization therapy, coronary artery disease (CAD) poising a leading cause of morbidity and mortality risks worldwide, continues to challenge the medical community. This study aimed at examining the efficacy of bone marrow stem cells combination therapy used for cardiovascular regenerative therapies, and also to identify isolation procedure of autologous bone marrow stem cells (ABMSCs) might affect cell functionality and therapeutic efficacy, administrated through intra-myocardial and during coronary artery bypass graft (CABG).Materials and Methods: The Yazd Cardiovascular research center was investigating to establish a xeno-free protocol with lees processing steps for cell therapy and treatment of cardiovascular disease. After thoughtful consideration of both statistical and clinical principles, we recruited 15 patients to receive either combinations of ABMSCs or placebo. The overall baseline age of the patients was 60+9 years, and due to severe ischemic cardiomyopathy, need to have coronary bypass surgery. Each patient received a median of 5×107±1×107 ABMSC combinations harvested by the special procedure or an equal volume of diluent (placebo). Changes in left ventricular ejection fraction from baseline and wall motion, examined by magnetic resonance imaging and by echocardiography, respectively.Results: ABMSC delivery was successful in all patients with no arrhythmias, no elevated cardiac enzymes or complications related to the delivery. Compared with the placebo-control group, the ABMSC group had significant changes in routine clinical and biochemical test values (p<0.05). Weekly angina frequency was significantly lower in the cell-injected group than in placebo group. Left ventricular ejection fraction, end-systolic volume and wall motion was found to be significantly improved in the ABMSC group compared to the placebo group over the follow-up period.Conclusion: The designed protocol should be considered as an alternative method of ABMSC application in clinical trial for improving blood flow and contractile function of the heart, and also to safely deliver large number of cells regardless of different stem cell processing steps and RBC or xeno-contamination. This study indicates that the beneficial effect of special way which we used for ABMSC transplantation, would be pronounced in CAD patients.

In this paper, we consider statistics on permutations of lengthn represented geometrically as bargraphs having the same number of horizontal steps. More precisely, we nd the joint distribution of the descent and up step statistics on the bargraph representations, thereby obtaining a new rened count of permutations of a given length. To do so, we consider the distribution of the parameters on permutations of a more general multiset of which Sn is a subset. In addition to nding an explicit formula for the joint distribution on this multiset, we provide counts for the total number of descents and up steps of all its members, supplying both algebraic and combinatorial proofs. Finally, we derive explicit expressions for the sign balance of these statistics, from which the comparable results on permutations follow as special cases.