Several hundred sporophores of Ganoderma were collected from 5 - 40 years old palm trees infected with basal stem rot in 5 oil palm estates in Peninsular Malaysia. Based on the morphometric studies of the pores, dessepiments and basidiospores dimensions and other morphological characteristics, the sporophores were identified as belonging to a single species, G. boninense Pat

Akgun, Berk

Koyluoglu, O. Ozan

Krunz, Marwan

IEEE Transactions on Information Forensics and Security

arXiv

© 2018 IEEE. We consider a single-cell massive multiple-input multiple-output (MIMO) system in which a base station (BS) with a large number of antennas transmits simultaneously to several single-antenna users. The BS acquires the channel state information (CSI) for various receivers using uplink pilot transmissions. We demonstrate the vulnerability of the CSI estimation process to pilot-contamination (PC) attacks. In our attack model, the attacker aims at minimizing the sum rate of downlink transmissions by contaminating the uplink pilots. We first study these attacks for two downlink power allocation strategies under the assumption that the attacker knows the locations of the BS and its users. Later on, we relax this assumption and consider the case when such knowledge is probabilistic. The formulated problems are solved using stochastic optimization, Lagrangian minimization, and game-theoretic methods. A closed-form solution for a special case of the problem is obtained. Furthermore, we analyze the achievable individual secrecy rates under PC attacks and provide an upper bound on these rates. We also study this scenario without a priori knowledge of user locations at the attacker by introducing chance constraints. Our results indicate that such attacks can degrade the throughput of a massive MIMO system by more than 50%

Akgun, B

Krunz, M

Ozan Koyluoglu, O

OPUS - University of Technology Sydney

Vulnerabilities of massive MIMO systems to pilot contamination attacks

Ho, Yin Wan

Nawawi, A.

Universiti Putra Malaysia Institutional Repository

Pertanika 8(3), 425 - 428 (1985)COMMUNICATION IGanoderma boninense Pat. from Basal Stem Rot of Oil Palm(Elaeis guineensis) in Peninsular MalaysiaABSTRAKBeberapa ratus sporofor bagi Ganoderma adalah dikumpulkan daripada kelapa sawit yangberumur 5 - 40 tahun dengan reputan pangkal batang dalam 5 buah estet kelapa sawit di Semenan-jung Malaysia. Berdasarkan kepada kajian morfometrik bagi dimensi liang, desepimen dan basidio-spora dan ciri-ciri morfologi lain bagi sporofor, sporofor itu dikenalpastikan sebagai satu spesies, G.boninense Pat.ABSTRACTSeveral hundred sporophores of Ganoderma were collected from 5 - 40 years old palm treesinfected with basal stem rot in 5 oil palm estates in Peninsular Malaysia. Based on the morphometricstudies of the pores, dessepiments and basidiospores dimensions and other morphological characte-ristics, the sporophores were identified as belonging to a single species, G. boninense Pat.INTRODUCTIONThe basal stem infection of oil palm (Elaeisguineensis Jacq.) by Ganoderma in Malaysia wasfirst recorded by Thompson in 1931. For manyyears, the disease was thought to be economicallyunimportant as only very old palms over 25 yearswere infected. It was normal practice to leave theinfected palm to rot away by itself in the field.Such was the situation until around 1957 -1958when Ganoderma infections were reported to beincreasing in many estates and affecting muchyounger palms of around 5 years old. Basal stemrot was more prevalent in coastal areas than ininland areas and incidence of disease on youngpalms was higher in areas previously grown withcoconut (Turner, 1965a). The disease is nowconsidered to be the most annihilating disease offield palms causing significant losses in SoutheastAsia (Turner, 1981). The disease has also beenrecorded in Indonesia, Nigeria, Ghana, Zaire,Cameroun, Angola, Tanzania and NorthRhodesia (Turner, 1981).The taxonomy of Ganoderma species asso-ciated with the disease is still controversial. InMalaysia, several Ganoderma species particular-ly G. lucidum (Navaratnam, 1961; 1964;Turner, 1965b) had been reported to he thecausal agent of the disease. However, reports ofSteyaert (1967, 1972) showed that G. lucidum isconfined mainly to temperate regions. Thispaper reports the identification of Ganodermasporophores from palms infected with basal stemrot from various oil palm estates in PeninsularMalaysia.MATERIALS AND METHODSCollection of Ganoderma sporophores weremade from infected field palms ranging from5 - 40 years in Highland Estate, Kelang,Selangor; United Plantations, Teluk Intan,Perak; Oil Palm Research Station, Banting,Selangor; Layang-Layang Oil Palm ResearchStation, Johore and Federal Land DevelopmentAuthority, Jerantut, Pahang. A hundredsporophores were collected from each of theestates mentioned. Sporophores were also col-lected from cut stumps (about 80 cm high) of in-fected oil palm from the same estates incubatedin a shady area of the Botaq.y Garden in Univer-sity of Malaya.Y.W. HO AND A. NAWAWIThe method for preparation of sporophoresections for microscopic examination was adapt-ed from the method by Steyaert (1967). Asample of 10 pores, 10 dessepiments and 50basidiospores were measured for each sporo-phore. For each pore, two perpendiculardiameters were measured and for each basi-diospore' the length and width were taken.Basidiospores were collected either bysqueezing the spores out of the pore layer ontothe slides or by placing a .clean slide under asporulating sporophore. The basidiospores weremounted with Canada Balsam. Excess xylenefrom the Canada Balsam was eliminated bygentle warming. The basidiospores prepared bythis method were found to retain their form andsize without shrinkage.The system of Steyaert (1967, 1972) wasused for identification of Ganoderma species. Allspecimens identified were re-confirmed by Dr.R. L. Steyaert of Jardine Botanique De L'Etat,Brussel, Belgium.RESULTS AND DISCUSSIONFrom macroscopic and microscopic exami-nations, the sporophores collected could bedivided into 2 groups.Sporophores in the first group measured upto 11 cm in diameter but the majority wereabout 5 cm in diameter. They were either stalk-ed or sessile. Some were flat and bracket-shap~d~others were lobed. The dorsal surface was glossy,blackjsh-brown in colour with concentric mark-ings. The edge was white when fresh. The under-surface was also white. The cuticle was about 70PPl thick, underlain by a fine yellow margin. Thebases of the tubes were auburn in colour. Thecuticle was made up of globular, stalked ele-ments, somewhat wedge-shaped, 30 - 50 p.-nlong and 5 - 10 Pim wide at the terminal globularpart. The pores were circular, 110 - 300 P\ffi indiameter. The dessepiments measured 30 - 130P~ and distances between the axes of pores were185 - 235 prtn. Basidiospores were yellowish-brown, ellipsoidal, 8.5 -11.5 X 5.2 - 6.5 Piffi.The sporophores in the second group weremuch larger, usually measuring up to 15 cm indiameter. They were either stalked or sessile.The dorsal surface was shiny and varnished,orange-coloured in young sporophore, deepen-ing to a dark-brown colour with concentric rings.when mature. The growing margin was notwhite as in the first type but was orange. Thecuticle was thin (about 40 J,Llm) with globularelements measuring 60 -75 Piffi long an4- 7 -12plJX1 wide at the apex. The context layer wasbrown and very thick, constituting about ~ to% of the total thickness of the sporophore. Thepores were circular, 90 - 220 pm in diameter,the dessepiments were about 20 - 100 pro thickand the distances between the axes of the poreswere 110 - 220 pm. Basidiospores were pale-brown, ellipsoidal, averaging 9.0 -12.5 X 4.5-7.0.J..L~.Personal communication with Steyaert con-firmed sporophores of the first group to be G.bonz'nense Pat. (Plate 1) and the sporophores ofthe second group was suggested to be "G. m£n£-atocinctum Stey.-like".PltJtel: S/HWoplaorw 0/ G........... Oft in/ectedstem of oil palm.426 PERTANIKA VOL. 8 NO.3, 1985G. BONINENSE PAT. FROM BASAL STEM ROT OF OIL PALM IN PENINSULAR MALAYSIAIt was observed that the morphology andsize of the basidiospore, dessepiment, pore andthe distance between the axes of the pores weresimilar in both G. bont'nense and G. mt'nt'ato-dnctum. However, the morphology of the sporo-phores and the measurements of the cuticlethickness were slightly different. It was mainlyfrom these differences especially the orangeborder in the sporophore that Steyaert (1967)distinguished G. mt'nt'atocz'nctum as a separatespecies from G. bont'nense. However, later(1973, personal communication) Steyaert doubt-ed the validity of separating G. mt'nt'atocinctumas a new species based mainly on the presence ofthe orange border. He felt that if the orangeborder was not permanent, G. minz'atodnctumcould be considered as a synonym of G. boni-nense. Since the orange borders of the sporo-phores of the second group ("G. minz'atocinc-tum-like") were not distinct when the sporo-phores stopped growing it is very likely thatsporophores of this group are also G. boninense.The measurements of the sporophores andbasidiospores ~f G. boninense'in this study werequite similar to those reported by Varghese etal., (1976) for unidentified Ganoderma speciesfrom basal stem rots of oil palm. The morpho-IOgTcal characteristics of their sporophores andbasidiospores (pore size, 122.8 - 179.8 }.L\Ill; des-sepiment thickness, 81.8 - 179.3 J.LIID; basidio-spore, 6.4 -12.5 X 3.6 - 6.8 ·wen) conformedwith those of G. boninense. They also reportedthat the morphological and physiologicalcharacteristics of the Ganoderma species causingbasal stem rot in oil palm were clearly differentfrom the Ganoderma species causing basal stemrot in tea and Hevea rubber.It is found from the present survey of Gano-derma in the various oil palm estates that G.bont'nense is not confined to anyone area but ispresent in all the estates surveyed. The speciescan cause serious infection in palms above 5years of age.Steyaert"(1967) reported that the hosts of G.bonine~e (specimens se~t by Turner in 1965,collected from the Oil Palm Research StationBanting) were mainly c~conut palms. Now, G:bonz'nense is found to be associated with basalstem rot of oil palm not only in Banting estatebut also in many other oil palm estates.Previous reports by other workers (Vargheseet al., 1976; Turner, 1981) suggested that severalspecies and not just one species may be involvedin causing the disease but whether the species areall equally virulent and whether dual or multipleinfection can occur are not known (Turner,1981).ACKNOWLEDGEMENTSThanks are due to Dr. R.L. Steyaert ofJardine Botanique De L'Etat Brussel, Belgiumfor confirming the identification of all thespecimens and for his invaluable suggestions andcomments.Y.W.HoA. Nawawi 1Department of Bt'ology,Faculty of Sdence and Environmental Studies,Universz'ti Pertanian Malaysia,Serdang, Selangor, Malaysia.REFERENCESNAVARATNAM, 5.1. (1961): Successful inoculation ofoil palms with a pure culture of Ganodermalucidum. Malay. Agr.J. 4:J: 233 - 238.NAVARATNAM, 5.1. (1964): Basal stem rot of oil palmson ex-coconut estates. Planter. 40: 256 - 259:5TEYAERT, R.L. (1967): Les Ganoderma palmicoles.Bull.Jard. Bot. Nat. Belg. :J7: 465 - 492.STEYAERT, R.L. (1972): Species of. Ganoderma andrelated genera mainly of Bogor and Leidenherbaria. Persoonia. 7: 55 - 118.THOMPSON, A. (1931): Stem rot of oil palm in Malaya.Bull. Dep. Agr. S.S. and F.M.S., Sci. Ser. 6.TURNER, P.O. (1965a): The incidence of Ganodermadisease of oil palms in Malaya and its relation toprevious crop. Ann. Appl. Biol. 55: 417 - 423.IDepartment of Botany, University of Malaya, Kuala Lumpur, Malaysia.PERTANIKA VOL. 8 NO.3, 1985Y.W. HO AND A. NAWAWITURNER, P.D. (1965b): Infection of oil palms byGanoderma. Phytopathological notes. Phyto-pathology. 55: 957.TURNER, P.D. (1981): Oil Palm Diseases and Dis-orders. The Incorporated Society of Planters,Kuala Lumpur, Malaysia.VARGHESE, G., CHEW, P.S. and LIM, J.K. (1976):Biology and chemically assisted biological contr()lof Ganoderma. Proc. Int. Rubb. Con[, KualaLumpur, 1975, III: 278 - 292.(Recez'ved 10 September, 1985) .428 PERTANIKA VOL. 8 NO.3, 1985

Ganoderma boninense Pat. from basal stem rot of oil palm

(Elaeis guineensis) in Peninsular Malaysia

We consider a single-cell massive multiple-input multiple-output (MIMO) system in which a base station (BS) with a large number of antennas transmits simultaneously to several single-antenna users. The BS acquires the channel state information (CSI) for various receivers using uplink pilot transmissions. We demonstrate the vulnerability of the CSI estimation process to pilot-contamination (PC) attacks. In our attack model, the attacker aims at minimizing the sum rate of downlink transmissions by contaminating the uplink pilots. We first study these attacks for two downlink power allocation strategies under the assumption that the attacker knows the locations of the BS and its users. Later on, we relax this assumption and consider the case when such knowledge is probabilistic. The formulated problems are solved using stochastic optimization, Lagrangian minimization, and game-theoretic methods. A closed-form solution for a special case of the problem is obtained. Furthermore, we analyze the achievable individual secrecy rates under PC attacks and provide an upper bound on these rates. We also study this scenario without a priori knowledge of user locations at the attacker by introducing chance constraints. Our results indicate that such attacks can degrade the throughput of a massive MIMO system by more than 50%.National Science Foundation [CNS-1409172, CNS-1513649, IIP-1265960, CNS-1748692]; Qatar Foundation [NPRP 8-052-2-029]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 repository@u.library.arizona.edu

Ozan Koyluoglu, O.

The University of Arizona

Vulnerabilities of Massive MIMO Systems to Pilot Contamination Attacks

http://psasir.upm.edu.my/2372/1/Ganoderma_boninense_Pat._from_Basal_Stem_Rot_of_Oil_Palm.pdf

Ganoderma boninense Pat. from basal stem rot of oil palm (Elaeis guineensis) in Peninsular Malaysia

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