Exploiting Lack of Hardware Reciprocity for Sender-Node Authentication at the PHY Layer

This paper proposes to exploit the so-called reciprocity parameters (modelling non-reciprocal communication hardware) to use them as decision metric for binary hypothesis testing based authentication framework at a receiver node Bob. Specifically, Bob first learns the reciprocity parameters of the legitimate sender Alice via initial training. Then, during the test phase, Bob first obtains a measurement of reciprocity parameters of channel occupier (Alice, or, the intruder Eve). Then, with ground truth and current measurement both in hand, Bob carries out the hypothesis testing to automatically accept (reject) the packets sent by Alice (Eve). For the proposed scheme, we provide its success rate (the detection probability of Eve), and its performance comparison with other schemes

Molecular phylogeny and morphological characterization of Leucocoprinus birnbaumii from Punjab, Pakistan

Background: Leucocoprinus in Agaricaceae is a genus distributed worldwide and represented by nearly 50 species. From Pakistan, only four species in this genus have been known so far.Methods: The specimen was identified by morphological and anatomical characters combining with sequence analysis of nrDNA-ITS region.Results: Leucocoprinus birnbaumii, a bright yellow mushroom found on wood log from Sialkot district, Punjab, Pakistan. This species is identified by its medium sized bell-shaped pileus bearing the same colored squamule with sulcate striate margins, presence of metachromatic basidiospores and pseudoparaphyses around the basidia. Molecular data also supported its taxonomy as L. birnbaumii. The species is being described for the first time based on morphological and anatomical characters in combination with molecular phylogeny using ITS region of nrDNA.Conclusion: Leucocoprinus birnbaumii is widely distributed in Asia, Africa, Europe, North America and South America. It grows in tropical and sub-tropical areas. Its occurrence in Sialkot, Punjab, Pakistan with humid subtropical climate represents its wide ecological amplitude and geographic distribution.Keywords: Humid subtropical climate; ITS; nrDNA; Taxonomy   

Dissemination of Bt cotton in cotton growing belt of Pakistan

AbstractBackground: Adoptability of biotech crops has climbed up dramatically in the world from 1.7 million hectares in its introductory period in 1996 to 170 million hectare in 2012. Area planted to biotech crop increased to over one-fourth of the world total in 2005-06. The data collected also demonstrates that developing countries like Pakistan are making tremendous development in production of Biotech crops especially cotton.Methodology: Random samples have been collected and received from different cotton growing areas of Pakistan from 2007 to date for Bt gene confirmation and expression. Genomic DNA was isolated and analyzed through internal reference primers from SadI gene of cotton genome. Samples were analyzed by PCR for detection of Bt genes including CEMB Cry1Ac+2A double Bt gene. ELISA was done for confirmation of Bt protein by using Envirologix Quantiplate ELISA kit Cry1Ab/Ac Cat # AP003 and Quantiplate ELISA kit Cry2A Cat # AP005 according to manufacturer instruction.Results: Development of Bt Cotton in Pakistan is as old as in advanced countries of the world. Pakistan has become the fourth country of the world for production of indigenous Bt cotton by utilizing their local cotton varieties for genetic modifications. The support of various documentary proofs like research articles, patents, projects, Ph. D and M.Phil studies generated by Centre of Excellence in Molecular Biology (CEMB) greatly strengthen the data of Bt cotton development in Pakistan. Pakistan Central Cotton Committee (PCCC)declared locally developed Bt cotton as the best performing of all over Pakistan among other international product.Conclusion: Progress made in development of indigenous Bt cotton variety by CEMB Pakistan and their excellent performance in field determined their increased adoptability ratio in farmers. The formal approval process which is going to be completed in near future will open the doors for farmers and breeders to utilize this material for better economy of Pakistan

PHY Layer Authentication via Drifting Oscillators

PHY layer authentication of a wireless sender has gained much interest recently. In this paper, we consider the famous Alice, Bob and Eve model and investigate (for the first time) the feasibility of using time-varying clock offsets for sender-node-authentication at Bob. Specifically, we exploit the fact (and de-facto problem) that clock offset between every node pair is unique; moreover, the two clock offsets between any two node pairs drift independently and randomly over time. Therefore, an explicit mechanism is needed to track the time-varying clock offsets. To this end, we model oscillator drift as brownian motion frequency and phase drift, and present a novel framework which is based on interplay between a hypothesis testing device and a bank of two Kaiman filters; one KF (KFh0) tracks Alice's clock while other KF (KFh1) tracks Eve's clock. Building on aforementioned framework, we then propose a novel sender-node-authentication method (so-called MHF method) by means of which Bob can automatically accept (reject) a received packet if it is sent by Alice (Eve). Finally, simulation results are presented which corroborate the efficiency of the proposed method.QC 20150223</p

The effects of remote ischaemic preconditioning when combined with dexmedetomidine on renal ischaemia reperfusion injury in rats

Uzak İskemik Önkoşullama İle Birlikte Kullanılan Deksmedetomidinin Sıçan Renal İskemi Reperfüzyon Hasarına Etkileri Dr.Emine AYDIN, DEÜTF Anesteziyoloji ve Reanimasyon AD, İZMİR Amaç: Bu çalışmada sıçan renal iskemi reperfüzyon (İR) modelinde, tek taraflı alt ekstremiteye uygulanacak uzak iskemik önkoşullama (UİÖK) ile birlikte deksmedetomidin verilmesinin böbrek hasarına etkisini histopatolojik ve aktif kaspaz 3 immunoreaktivitesini değerlendirmek amaçlanmıştır. Gereç ve Yöntem: Ağırlıkları 250-300 g arasında değişen 28 adet sıçan dört gruba ayrıldı. Grup I (Sham,n=7)'de laparotomi sonrası anestezinin 65. dk.'sinde renal pediküller açığa çıkarılarak sıçanlar 130 dk. anestezi altında bekletildi. Grup II (İR,n=7)'de anestezinin 65. dk.'sinde bilateral renal pediküllere klemp konuldu, 60 dk. iskemi uygulanıp ardından klemp açılarak 24 saat reperfüzyon yapıldı. Grup III (İR+deksmedetomidin,n=7)'de Grup II'deki işlemin ardından reperfüzyonun 5. dk.'sinde 100 mcg/ kg intraperitoneal deksmedetomidin verildi, 24 saat reperfüzyon yapıldı. Grup IV (İR+UİÖK+Deksmedetomidin,n=7)'de laparotomi sonrası sol arka bacağa 3 döngü 10/ 10 dk. İ/R uygulandıktan 5 dk. sonra (toplam 65 dk. sonra) Grup III'deki işlemler tekrarlandı. Bulgular: Histopatolojik hasar skorları ve aktif kaspaz-3 immunreaktivitesi Sham grubunda diğer gruplara göre anlamlı olarak düşük bulundu. Grup III ve IV'de, Grup II'ye göre histopatalojik hasar skoru daha düşük saptandı (p=0,03, p=0,05). Aktif kaspaz-3 immunreaktivitesi Grup II ile kıyaslandığında Grup IV'de anlamlı olarak düşük bulunurken (p=0,01), Grup II ve Grup III arasında anlamlı fark saptanmadı (p=0,06). Sonuç: Deksmedetomidin ile farmakolojik koşullama ve UİÖK'ye deksmedetomidin eklenmesi böbrek İR hasarını histomorfolojik olarak anlamlı düzeyde azaltmakta, iki yöntemin birlikte uygulanması aktif kaspaz 3 üzerinden apoptozisi önlemektedir The Effects of Remote Ischaemic Preconditioning When Combined with Dexmedetomidine on Renal Ischaemia Reperfusion Injury In Rats Dr. Emine AYDIN, Dokuz Eylul University, School of Medicine, Dept. of Anaesthesiology, IZMIR Background: The aim of this study was to evaluate the effects of remote ischaemic preconditioning (RIP) by brief ischemia of unilateral hind limb when combined with dexmedetomidine on renal ischaemia reperfusion (IR) injury by histopathology and active caspase-3 immunoreactivity in rats. Materials and Methods: 28 Wistar albino male rats weighing approximately 250-300 g were divided into 4 groups. Group I (Sham,n=7): Laparotomy and renal pedicle dissection were performed at 65th min of anaesthesia and the rats were observed under anaesthesia 130 minutes. Group II (IR,n=7): At 65th min of anaesthesia bilateral renal pedicles were clamped. After 60 min ischaemia 24 hours of reperfusion was performed. Group III (IR+dexmedetomidine,n=7): The same surgical procedure was performed with IR group and at the fifth minute of reperfusion (100 µg /kg intra-peritoneal) dexmedetomidine was administered. Reperfusion lasted 24 hours. Group IV (IR+RIP+dexmedetomidine,n=7): After laparotomy, three cycles of ischaemic preconditioning (10 min ischaemia and 10 min reperfusion) were applied to the left hind limb and after five minutes, the same procedure was performed with group III. Results: Histopathological injury scores and active caspase-3 immunoreactivity was significantly lower in the Sham group compared to the other groups. Histopathological injury scores in group III and IV were significantly lower than group II (p=0.03, p=0.05). Active caspase-3 immunoreactivity was significantly lower in the group IV than group II (p=0.01) and there was no significant difference between group II and III (p=0.06). Conclusions: Pharmacologic conditioning with dexmedetomidine and RIP when combined with dexmedetomidine significantly decreases renal IR injury histomorphologically. Combined use of two methods prevents apoptosis via active caspase

A Distributed Relay Beamforming-enhanced TDMA System

Token-passing wireless network protocols (TP-WNP) (e.g., EchoRing), designed for hard real-time systems, typically need to provide ultra-low-latency coupled with ultra-high-reliability guarantees. In this paper, we initiate a study to investigate the feasibility of distributed relay beamforming (DRBF) in a TP-WNP with the aim to enhance its reliability (and latency) performance even further. Specifically, we consider employing &amp;#36;N&amp;#36; i) amplify-and- forward (AF), ii) decode-and-forward (DF) relays in a wireless network running a TP-WNP. The relays operate in FDD mode, and do distributed transmit beamforming to realize low-latency, highly- reliable communication between each of the &amp;#36;M&amp;#36; source- destination pairs in the TP-WNP (a.k.a TDMA) system. The enablers/pre-requisites for the proposed DRBF-TDMA system are frequency, phase and timing synchronization among the relay nodes. To this end, we propose a novel distributed method for frequency synchronization among the AF/DF relay nodes operating in FDD mode. Furthermore, for oscillators with drift, we derive a rule of thumb which provides us the maximum relaying delay &amp;#36;T_{delay}&amp;#36; up to which the proposed frequency synchronization method is effective. For phase and timing synchronization, we employ standard techniques from the literature. Our simulation results verify the analytical results, i.e., by means of proposed DRBF using &amp;#36;N&amp;#36; AF (DF) relays, upto a factor of &amp;#36;N&amp;#36; (&amp;#36;N^2&amp;#36;) gains in received SNR can be achieved, at each of the &amp;#36;M&amp;#36; destination nodes in the proposed system.QC 20150715</p

Engineered Disease Resistance in Cotton Using RNA-Interference to Knock down Cotton leaf curl Kokhran virus-Burewala and Cotton leaf curl Multan betasatellite Expression

Cotton leaf curl virus disease (CLCuD) is caused by a suite of whitefly-transmitted begomovirus species and strains, resulting in extensive losses annually in India and Pakistan. RNA-interference (RNAi) is a proven technology used for knockdown of gene expression in higher organisms and viruses. In this study, a small interfering RNA (siRNA) construct was designed to target the AC1 gene of Cotton leaf curl Kokhran virus-Burewala (CLCuKoV-Bu) and the beta C1 gene and satellite conserved region of the Cotton leaf curl Multan betasatellite (CLCuMB). The AC1 gene and CLCuMB coding and non-coding regions function in replication initiation and suppression of the plant host defense pathway, respectively. The construct, V b, was transformed into cotton plants using the Agrobacterium-mediated embryo shoot apex cut method. Results from fluorescence in situ hybridization and karyotyping assays indicated that six of the 11 T-1 plants harbored a single copy of the V beta transgene. Transgenic cotton plants and non-transgenic (susceptible) test plants included as the positive control were challenge-inoculated using the viruliferous whitefly vector to transmit the CLCuKoV-Bu/ CLCuMB complex. Among the test plants, plant V beta-6 was asymptomatic, had the lowest amount of detectable virus, and harbored a single copy of the transgene on chromosome six. Absence of characteristic leaf curl symptom development in transgenic V beta-6 cotton plants, and significantly reduced begomoviral-betasatellite accumulation based on real-time polymerase chain reaction, indicated the successful knockdown of CLCuKoV-Bu and CLCuMB expression, resulting in leaf curl resistant plants.Pakistan-U. S. Cotton Productivity Enhancement Program, ICARDA - United States Department of Agriculture (USDA), Agricultural Research Service (ARS) [58-6402-0-178F]; USDA-ARS Non-Assistance [58-6402-2-763]; Cotton Incorporated-Core Program [06-829]Open Access Journal.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]