New Reassembly Buffer Management System in 6LoWPAN

Recently, Internet of Thing (IoT) appears to be a new paradigm foreverything to be connected seamlessly to the Internet. One of the standards used to fitthe low power devices into IoT is IEEE 802.15.4 wireless sensor network (WSN). Tosupport IPv6 packet transmission over the IEEE 802.15.4 networks, the IPv6 overLow power Wireless Personal Area Network (6LoWPAN) adaptation layer isnecessary. The 6LoWPAN adaptation layer divides the packet into a number offragments before it is transmitted. At the receiver, these fragments will be reassembledto become the original packet. However, the existing reassembly process in theadaptation layer fails to consider the irregular arrival sequence of fragments which cancause the packet that has been reassembled to be corrupted. This serious impedimentin reassembly mechanism can cause unacceptable packet lost. In this paper, a newreassembly mechanism namely Multi-Reassemblies Buffer Management System (MRBMS)is proposed in the context of providing efficient 6LoWPAN packetsreassembly. In this proposed mechanism multiple reassembly buffers are createddynamically such that multiple reassembly sessions can be processed simultaneously.Each reassembly session is responsible for a packet reconstruction. The performanceof proposed MR-BMS is compared with RFC 4944-based reassembly mechanism andSICSlowPAN implementation. Results show that the proposed mechanismoutperforms RFC 4944-based reassembly mechanism and SICSlowPANimplementation with 121.7% and 16.2% higher packet delivery ratio respectivelywhen packet encountered more fragmentation. Moreover, the proposed MR-BMS hasa comparable average energy consumption with other mechanisms

Mobility management schemes and mobility issues in low power wireless sensor network

One of the current most significant active research areas in wireless communication technologies is Wireless Sensor Network (WSN). WSN is widely adopted in the ubiquitous networking due to its large applications in different fields such as healthcare, agriculture, livestock monitoring, and etc. WSN is labeled as less reliable due to few drawbacks such as energy consumption, networking cost, mobility management, and etc. The mobility management issue was given less attention in the WSN because the significant of seamless connectivity is underestimated. Based on analysis of recent literatures, our paper seeks to address the mobility issues in WSN. This paper gives an overview of the available mobility management schemes and examines mobility issues of nodes in network-based mobility schemes

Bridging the data gaps in the epidemiology of hepatitis C virus infection in Malaysia using multi-parameter evidence synthesis

BACKGROUND: Collecting adequate information on key epidemiological indicators is a prerequisite to informing a public health response to reduce the impact of hepatitis C virus (HCV) infection in Malaysia. Our goal was to overcome the acute data shortage typical of low/middle income countries using statistical modelling to estimate the national HCV prevalence and the distribution over transmission pathways as of the end of 2009. METHODS: Multi-parameter evidence synthesis methods were applied to combine all available relevant data sources - both direct and indirect - that inform the epidemiological parameters of interest. RESULTS: An estimated 454,000 (95% credible interval [CrI]: 392,000 to 535,000) HCV antibody-positive individuals were living in Malaysia in 2009; this represents 2.5% (95% CrI: 2.2-3.0%) of the population aged 15-64 years. Among males of Malay ethnicity, for 77% (95% CrI: 69-85%) the route of probable transmission was active or a previous history of injecting drugs. The corresponding proportions were smaller for male Chinese and Indian/other ethnic groups (40% and 71%, respectively). The estimated prevalence in females of all ethnicities was 1% (95% CrI: 0.6 to 1.4%); 92% (95% CrI: 88 to 95%) of infections were attributable to non-drug injecting routes of transmission. CONCLUSIONS: The prevalent number of persons living with HCV infection in Malaysia is estimated to be very high. Low/middle income countries often lack a comprehensive evidence base; however, evidence synthesis methods can assist in filling the data gaps required for the development of effective policy to address the future public health and economic burden due to HCV. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12879-014-0564-6) contains supplementary material, which is available to authorized users

Anti-Allergic Cromones Inhibit Histamine and Eicosanoid Release from Activated Human and Murine Mast Cells by Releasing Annexin A1

PMCID: PMC3601088This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

In vitro induction and proliferation of protocorm-like bodies (PLBs) from leaf segments of Phalaenopsis bellina (Rchb.f.) Christenson

An in vitro culture procedure was established to induce protocorm-like bodies (PLBs) from leaf segments of the Phalaenopsis bellina (Rchb.f.) Christenson directly from epidermal cells without intervening callus on ½ strength modified Murashige and Skoog (MS) (in Physiol Plant 15:473–497, 1962) medium supplemented with 1-Naphthaleneacetic acid (NAA; 0, 0.1, 1 mg/l) and Thidiazuron (TDZ; 0, 0.1, 1, 3 mg/l). The best response was established at 3 mg/l TDZ which induced 78% of leaf segments to form a mean number of 14 PLBs per explant after 16 weeks of culture. No PLBs were found when leaf segments were cultured on ½ strength modified MS media supplemented with 0.1 and 1 mg/l NAA. The best induction percentage for auxin: cytokinin combination was at the combination of NAA and TDZ at 1.0 and 3.0 mg/l which gave 72% induction with 9 PLBs per explant. Semi-solid ½ strength MS and liquid Vacin and Went (VW) (in Bot Gaz 110:605–613, 1949) medium were used in order to find the highest survival and number of PLBs proliferation after 3 months in culture. Half strength MS showed an average of 9 PLBs in comparison with VW with an average of 5.3 PLBs per explants. Histological observations revealed that the regenerated PLBs were generally formed from the epidermal layers of the posterior regions of the leaf segments. Scanning electron micrograph of PLBs showed the origin of newly formed PLB from the peripheral region of leaf segments

Histone hyperacetylation disrupts core gene regulatory architecture in rhabdomyosarcoma

Core regulatory transcription factors (CR TFs) orchestrate the placement of super-enhancers (SEs) to activate transcription of cell-identity specifying gene networks, and are critical in promoting cancer. Here, we define the core regulatory circuitry of rhabdomyosarcoma and identify critical CR TF dependencies. These CR TFs build SEs that have the highest levels of histone acetylation, yet paradoxically the same SEs also harbor the greatest amounts of histone deacetylases. We find that hyperacetylation selectively halts CR TF transcription. To investigate the architectural determinants of this phenotype, we used absolute quantification of architecture (AQuA) HiChIP, which revealed erosion of native SE contacts, and aberrant spreading of contacts that involved histone acetylation. Hyperacetylation removes RNA polymerase II (RNA Pol II) from core regulatory genetic elements, and eliminates RNA Pol II but not BRD4 phase condensates. This study identifies an SE-specific requirement for balancing histone modification states to maintain SE architecture and CR TF transcription

Direct pathway for sticking/desorption of H2 on Si(100)

The energetics of H2 interacting with the Si(100) surface is studied by means of ab initio total energy calculations within the framework of density functional theory. We find a direct desorption pathway from the mono-hydride phase which is compatible with experimental activation energies and demonstrate the importance of substrate relaxation for this process. Both the transition state configuration and barrier height depend crucially on the degree of buckling of the Si dimers on the Si(100) surface. The adsorption barrier height on the clean surface is governed by the buckling via its influence on the surface electronic structure. We discuss the consequences of this coupling for adsorption experiments and the relation between adsorption and desorption.