Interference-Aware Hybrid MAC protocol for Cognitive Radio Ad-Hoc Networks with Directional Antennas

CR and PU hidden terminals in multi-channel Cognitive MAC protocols result in increased packet drops. This is due to inefficient node synchronization with existing “Control Channel” design. To date, In-band and Out-of-band CCC based MAC protocols are proposed to avoid PU and CR hidden terminals. But, In-band CCC based CR-MAC protocols cannot efficiently resolve the hidden terminal packet drops due to imperfect node synchronization whereas out-of-band CCC based MAC is vulnerable to intruder attacks and channel saturation. To overcome this, we propose an Interference-aware hybrid CCC cognitive MAC protocol with directional RTS/CTS and data transmission. In addition, adaptive power control algorithm is proposed to avoid interference to hidden PU and CR nodes at edge coverage area. Experimental results show that proposed Hybrid cognitive MAC protocol has increased link aggregate throughput and reduced cognitive control overhead in comparison with existing CCC based CR-MAC protocols

On the Eigenvalue Based Detection for Multiantenna Cognitive Radio System

Eigenvalue based spectrum sensing can make detection by catching correlation features in space and time domains, which can not only reduce the effect of noise uncertainty, but also achieve high detection probability. Hence, the eigenvalue based detection is always a hot topic in spectrum sensing area. However, most existing algorithms only consider part of eigenvalues rather than all the eigenvalues, which does not make full use of correlation of eigenvalues. Motivated by this, this paper focuses on multiantenna system and makes all the eigenvalues weighted for detection. Through the analysis of system model, we transfer the eigenvalue weighting issue to an optimal problem and derive the theoretical expression of detection threshold and probability of false alarm and obtain the close form expression of optimal solution. Finally, we propose new weighting schemes to give promotions of the detection performance. Simulations verify the efficiency of the proposed algorithms

Effects of different methionine sources on growth performance, meat yield and blood characteristics in broiler chickens

Three graded levels of MHA (methionine hydroxyl analogue) added into the broilers’ diets were based on the assumption that the relative bioavailability of MHA sources to DL-methionine (DLM) on a molar basis was 100%, 90% or 80% to meet the requirement of total sulphur amino acids. DLM was used as the reference control group. Live body weight at 21 and 35 days was retarded (p < 0.05) in chicks fed a diet containing 100% equivalent MHA-FA (methionine hydroxyl analogue free acid) across dietary treatments. Chicks fed the diet containing MHA-Ca vs. MHA-FA grew faster at 35 days (p < 0.05). Chicks consumed least (p < 0.05) when 100% equivalent MHA-FA was added during 1–21 days. FCR was enhanced in MHA-Ca (methionine hydroxyl analogue calcium salt) vs. MHA-FA at all days measured. MHA effect on mortality, being higher (p < 0.05) in chicks on MHA-FA vs. MHA-Ca, was noted. Serum concentration of total cholesterol was lowest (p < 0.05) in chicks fed on DLM-added diet, but highest (p < 0.05) in those fed 100% equivalent MHA-Ca. Serum concentration of immunoglobulin A was low (p < 0.05) in chicks fed on 100% or 80% equivalent MHA-Ca compared with the rest of treatments. Collectively, MHA-Ca performed better than MHA-FA as to performance traits

Tannin–Titanium Oxide Multilayer as a Photochemically Suppressed Ultraviolet Filter

UV filters can initiate redox reactions of oxygen and water when exposed to sunlight, generating reactive oxygen species (ROS) that deteriorate the products containing them and cause biological damages. This photochemical reactivity originates from the high chemical potential of UV filters, which also determines the optical properties desirable for sunscreen applications. We hypothesize that this dilemma can be alleviated if the photochemical pathway of UV filters is altered to coupling with redox active molecules. Here, we employ tannic acid (TA) as a key molecule for controlling the photochemical properties of titanium dioxide nanoparticles (TiO₂ NPs). TA provides an unusual way for layer-by-layer assembly of TiO₂ NPs by the formation of a ligand-to-metal charge transfer complex that alters the nature of UV absorption of TiO₂ NPs. The galloyl moieties of TA efficiently scavenge ROS due to the stabilization of ROS by intramolecular hydrogen bonding while facilitating UV screening through direct charge injection from TA to the conduction band of TiO₂. The TiO₂–TA multilayers assembled in open porous polymer microspheres substantially increased sun protection while dramatically reducing ROS under UV exposure. The assembled structure exhibits excellent in vivo anti-UV skin protection against epidermal hyperplasia, inflammation, and keratinocyte apoptosis without long-term toxicity

Establishment of Immunoglobulin Heavy (IGH) Chain Clonality Testing by Next-Generation Sequencing for Routine Characterization of B-Cell and Plasma Cell Neoplasms

Immunoglobulin heavy chain (IGH) clonality testing by next-generation sequencing (NGS) offers unique advantages over current low-throughput methods in the assessment of B-cell lineage neoplasms. Clinical use remains limited because assays are not standardized and validation/implementation guidelines are not yet developed. Herein, we describe our clinical validation and implementation of NGS IGH clonality testing and summarize our experience based on extensive routine use. NGS-based clonality testing targeting IGH FR1, FR2, FR3, and the conserved leader sequence upstream of FR1 was validated using commercially available kits. Data were analyzed by commercial and in-house–developed bioinformatics pipelines. Performance characteristics were evaluated directly comparing with capillary electrophoresis (CE) assays (BIOMED-2 primers). Assays were monitored after implementation (>1.5 years), concurrently testing by CE methods. A total of 1189 clinical samples were studied (94 validation, 1095 postimplementation). NGS showed superior performance compared with CE assays. For initial assessment, clonality detection rate was >97% for all malignancy types. Concordance with CE was 96%; discordances were related to higher sensitivity/resolution of NGS and improved detection in cases with high somatic hypermutation. Routine NGS clonality assessment is feasible and superior to existing assays, enabling accurate and specific index clone assessment and future tracking of all rearrangements in a patient sample. Successful implementation requires new standardization, validation, and implementation processes, which should be performed as a multicenter and multidisciplinary collaboration