A new security model to prevent denial‐of‐service attacks and violation of availability in wireless networks

Wireless networks are deployed in many critical areas, such as health care centers, hospitals, police departments, and airports. In these areas, communication through the networks plays a vital role, and real‐time connectivity along with constant availability of the networks is highly important. However, one of the most serious threats against the networks availability is the denial‐of‐service attacks. In wireless networks, clear text form of control frames is a security flaw that can be exploited by the attackers to bring the wireless networks to a complete halt. To prevent the denial‐of‐service attacks against the wireless networks, we propose two distinct security models. The models are capable of preventing the attacks by detecting and discarding the forgery control frames belonging to the attackers. The models are implemented and evaluated under various experiments and trials. The results have proved that the proposed models significantly improve the security performance of the wireless networks. This gives advantage of safe communication that can substantially enhance the network availability while maintaining the quality of the network performance. Copyright © 2011 John Wiley & Sons, Ltd.     

Formation of protein adducts of 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine in cooked foods

Heterocyclic amines (HCAs) are mutagenic and carcinogenic compounds found in cooked meat and fish. Although HCAs are known to form adducts with protein after metabolic activation, adduct formation during cooking has not been elucidated. In this study, we showed that 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) is released from high molecular weight compounds by acid or enzymatic hydrolysis of cooked foods. Formation of free and protein adduct forms of PhIP was dependent on cooking temperature and time, and PhIP–protein adducts were estimated to form after formation of free PhIP. We also demonstrated that PhIP–protein adduct is formed by heating of PhIP and albumin as a model protein. A new adduct peak including [M+H]⁺ (m/z=225) of PhIP as a fragment ion was detected in the high molecular weight fraction of heat‐treated protein by LC–MS analysis. From model experiments by heating of PhIP and amino acids, the adduct was estimated to be produced by condensation of the amino group of PhIP and the carboxyl group of protein. PhIP–protein adducts were detected in several cooked meat and fish at ng/g food level as PhIP content. These results suggest that food‐borne protein adducts of HCAs may influence human HCA exposure and carcinogenic risk.     

混凝土小型空心砌块复合墙体受弯和受剪性能试验研究

对两种连接方式(钢筋连接和钢丝网片连接)的混凝土小型空心砌块足尺复合墙体交替进行了平面内低周反复加载试验和先外后内低周反复加载试验(即平面外加载试验完成后再进行平面内加载试验),旨在了解复合墙体的开裂和裂缝发展过程以及墙体连接筋的应变变化,研究墙体的抗震性能和变形能力。平面外低周反复加载试验结果表明,两种连接方式复合墙体的延性性能几乎相同,钢丝网片连接能更好地增加墙体的整体性和平面外抗震性能。文中比较了复合墙体在平面外加载试验的基础上进行平面内加载与直接进行平面内加载试验结果的差异,对试验结果的分析表明,平面外加载试验后墙体裂缝的存在降低了墙体的刚度,故而再进行平面内加载试验时墙体的开裂荷载有所降低,但对极限荷载、墙体延性及耗能均无明显影响。     

Rev-erbα Knockout Reduces Ethanol Consumption and Preference in Male and Female Mice

Alcohol use is a contributor in the premature deaths of approximately 3 million people annually. Among the risk factors for alcohol misuse is circadian rhythm disruption; however, this connection remains poorly understood. Inhibition of the circadian nuclear receptor REV-ERBα is known to disrupt molecular feedback loops integral to daily oscillations, and impact diurnal fluctuations in the expression of proteins required for reward-related neurotransmission. However, the role of REV-ERBα in alcohol and substance use-related phenotypes is unknown. Herein, we used a Rev-erbα knockout mouse line and ethanol two-bottle choice preference testing to show that disruption of Rev-erbα reduces ethanol preference in male and female mice. Rev-erbα null mice showed the lowest ethanol preference in a two-bottle choice test across all genotypes, whereas there were no ethanol preference differences between heterozygotes and wildtypes. In a separate experiment, alcohol-consuming wildtype C57Bl/6N mice were administered the REV-ERBα/β inhibitor SR8278 (25 mg/kg or 50 mg/kg) for 7 days and alcohol preference was evaluated daily. No differences in alcohol preference were observed between the treatment and vehicle groups. Our data provides evidence that genetic variation in REV-ERBα may contribute to differences in alcohol drinking.     

Testis-Specific Isoform of Na+-K+ ATPase and Regulation of Bull Fertility

An advanced understanding of sperm function is relevant for evidence-based male fertility prediction and addressing male infertility. A standard breeding soundness evaluation (BSE) merely identifies gross abnormalities in bulls, whereas selection based on single nucleotide polymorphisms and genomic estimated breeding values overlooks sub-microscopic differences in sperm. Molecular tools are important for validating genomic selection and advancing knowledge on the regulation of male fertility at an interdisciplinary level. Therefore, research in this field is now focused on developing a combination of in vitro sperm function tests and identifying biomarkers such as sperm proteins with critical roles in fertility. The Na⁺-K⁺ ATPase is a ubiquitous transmembrane protein and its α4 isoform (ATP1A4) is exclusively expressed in germ cells and sperm. Furthermore, ATP1A4 is essential for male fertility, as it interacts with signaling molecules in both raft and non-raft fractions of the sperm plasma membrane to regulate capacitation-associated signaling, hyperactivation, sperm-oocyte interactions, and activation. Interestingly, ATP1A4 activity and expression increase during capacitation, challenging the widely accepted dogma of sperm translational quiescence. This review discusses the literature on the role of ATP1A4 during capacitation and fertilization events and its prospective use in improving male fertility prediction.     

铁细菌对L245钢腐蚀行为的影响研究

采用挂片、电化学实验和SEM等手段研究了L245钢在含有铁细菌(FB)的页岩气压裂产出水中的腐蚀行为.结果 表明:有、无FB压裂产出水都会对L245钢造成腐蚀,但失重分析和极化曲线分析都证明FB的存在促进了L245钢的腐蚀;电化学阻抗拟合结果表明,在不含FB的页岩气压裂产出水中,L245钢的腐蚀速率在前5d逐渐增大,后...     

Physicochemical and sensory characteristics of commercially available rice-based Doenjang and their correlation to consumer acceptability for Korean young adults

Food Science and Biotechnology - There is an increased demand for rice doenjang by consumers who are allergic to beans as well as for those seeking diverse flavors. The objective of this study was...     

The effects of storage time and sunlight on microplastic pollution in bottled mineral water

The microplastic particles (MPs) and effects of storage time and direct sunlight on the MPs in bottled mineral waters were investigated by three experiments conditions. The mean MPs concentration was 63.9 ± 38.9 MPs/L. Pellet forms, white/yellow colour and sizes < 100 μm were predominant MPs, accounted for 35.3%, 51% and 60.2% of the total MPs, respectively. Storage of bottled water under darkness and sunlight caused an increase of 1.5% and 2.5% of MPs pollution, respectively. Also, the estimated daily intake (EDI) of MPs was 2.1, 6.4 and 9.6 MPs/kg BW.day for adults, children and infants, respectively. It is concluded that high storage time and direct sunlight may lead to a greater MPs pollution in mineral water and also high human intake through drinking bottled water. Therefore, it is suggested to reduce the expiry date of the bottled mineral water and avoid sunlight contact before consumption.