On the leakage resilience of secure channel establishment

Secure communication channels are typically constructed from an authenticated key exchange (AKE) protocol, which authenticates the communicating parties and establishes shared secret keys, and a secure data transmission layer, which uses the secret keys to encrypt data. We address the partial leakage of communicating parties' long-term secret keys due to various side-channel attacks, and the partial leakage of plaintext due to data compression. Both issues can negatively affect the security of channel establishment and data transmission. In this work, we advance the modelling of security for AKE protocols by considering more granular partial leakage of parties' long-term secrets. We present generic and concrete constructions of two-pass leakage-resilient key exchange protocols that are secure in the proposed security models. We also examine two techniques--heuristic separation of secrets and fixed-dictionary compression--for enabling compression while protecting high-value secrets.

Konstruktioner och valens : Verbfraser med åt i ett jämförande perspektiv

Det har knappast undgått någon som är språkligt medveten att finlandssvenskan och sverigesvenskan skiljer sig åt till vissa delar. Olikheterna återfinns på olika språkliga nivåer. Mest kända och omskrivna är de lexikologiska skillnaderna, dvs. skillnaderna på ordplanet. Betydligt mindre uppmärksamhet har ägnats syntaktiska skillnader, dvs. skillnader i hur satser och meningar byggs upp. För att öka kunskapen om finlandssvensk syntax initierade Språkvetenskapliga nämnden vid Svenska litteratursällskapet i Finland projektet Svenskan i Finland – syntaktiska drag i ett jämförande perspektiv, som pågick åren 2004–2006. Min avhandling har kommit till inom ramen för det projektet. Prepositionerna (t.ex. av, i, på, för, till, åt osv.) är så kallade funktionsord som har till uppgift att binda samman de mer betydelsetunga orden till satser och meningar. Den finlandssvenska prepositionsanvändningen skiljer sig i viss mån från den sverigesvenska, och ”åt” är en av de prepositioner som ofta lyfts fram som exempel. Finlandssvenskarna säger t.ex. ”han gav en bok åt Lena” i stället för ”han gav en bok till Lena” eller ”han gav Lena en bok”. De säger ”berätta något åt någon” (i stället för ”för”) och de säger ”ringa åt någon” i stället för ”ringa någon”. Ett huvudsyfte med min undersökning är att ta reda på hur pass stora skillnaderna är om man ser till samtliga belägg på ”åt” i ett material och inte bara till sådana som man fäster sig vid för att man vet att de avviker i finlandssvenskan. Undersökningen är korpusbaserad. Det betyder att jag letat efter alla belägg på kombinationer av verb och prepositionen ”åt” i rätt stora textmassor som finns tillgängliga i elektronisk form. Materialet ligger i Språkbanken i Finland och omfattar huvudsakligen tidningstext och skönlitteratur. Jag har använt mig av en textmassa på sammanlagt ungefär 40 miljoner löpande ord, drygt 23 miljoner finlandssvenska och drygt 19 miljoner sverigesvenska. Det materialet gav ca 20 000 åt-belägg att studera, och det visade sig något oväntat att ”åt” inte alls är vanligare i finlandssvenskan än i sverigesvenskan när det gäller skriftspråk, åtminstone inte i professionella skribenters språk. Om man kompenserar för att den finlandssvenska och den sverigesvenska korpusen inte är helt lika i fråga om genrefördelning och ålder, kommer man fram till i stort sett samma frekvens för ”åt” i båda korpusarna. För den närmare analysen av vilka mönster åt-beläggen uppvisar har jag först och främst utnyttjat konstruktionsgrammatik men också ramsemantik och valensteori. Konstruktionsgrammatiken är ingen enhetlig teori, men tanken om grammatiska konstruktioner är gemensam. Konstruktioner representerar allt från generella syntaktiska mönster till specifika mönster för språkliga enskildheter. Uppfattningen om vad som ska inbegripas i begreppet varierar, men definitionen av ”konstruktion” som ”par (eller konstellationer) av form och betydelse” är gemensam. ”Konstruktion” avser aldrig konkreta belägg i texter eller yttranden utan alltid det abstrakta mönstret bakom dessa. Och varje yttrande är resultatet av att en stor mängd konstruktioner samverkar. I min analys har jag utgått ifrån att beläggen med ”åt” kan återföras på olika konstruktioner eller mönster utifrån vad som är gemensamt för grupper av belägg. Jag har sett på vad åt-frasen i samverkan med verbet har för funktion i beläggen. En åt-fras är syntaktiskt en prepositionsfras och består av en preposition och en rektion. Exempelvis utgör ordparet ”åt skogen” en prepositionsfras där ”skogen” är rektion. Ur mitt material har jag kunnat abstrahera fram fem övergripande mönster där referenten för rektionen har olika så kallade semantiska roller. Åt-frasen kan i kombination med verbet ange mål eller riktmärke, som i t.ex. svänga åt höger, dra åt helvete, ta sig åt hjärtat, luta åt en seger för IFK. Den kan för det andra ange mottagare (t.ex. ge varsin kaka åt hundarna, bygga en bastu åt sina svärföräldrar, skaffa biljetter åt en kompis). För det tredje kan åt-frasen avse en referent som har nytta (eller skada) av en aktion (t.ex. klippa häcken åt grannen, ställa in digitalboxen åt sin moster). Åt-frasen kan slutligen avse den eller det som är föremål antingen för en kommunikationsaktion (vinka åt sin son, skratta åt eländet) eller en attityd eller känsla (glädja sig åt framgången). Utöver dessa huvudmönster finns det ett antal smärre grupper av belägg som bildar egna mönster, men de utgör sammanlagt under 3 % i bägge korpusarna. Inom grupperna kan undermönster urskiljas. I t.ex. mottagargruppen representerar ”ge varsin kaka åt hundarna” överföringskonstruktion, ”bygga en bastu åt sina svärföräldrar” produktionskonstruktion och ”skaffa biljetter åt en kompis” ombesörjningskonstruktion. Alla typer är gemensamma för bägge materialen, men andelen belägg som representerar de olika typerna skiljer sig betydligt. I det sverigesvenska materialet står t.ex. det mönster där åt-frasen avser mål eller riktmärke för en mycket större andel av beläggen än i finlandssvenskan. Också andelen belägg där åt-frasen avser någon som har nytta (eller skada) av en aktion är mycket högre i det sverigesvenska materialet. I det finlandssvenska materialet står i gengäld mottagarbeläggen för över 50 % av beläggen medan andelen i det sverigesvenska materialet är bara 30 %. Inom gruppen utgör belägg av produktions- och ombesörjningstyp dessutom en mindre andel i det finlandssvenska materialet än i det sverigesvenska. Dessa står till sin funktion nära den typ som avser den som har nytta av aktionen. De konkreta beläggen på överföring (ge varsin kaka åt hundarna) utgör en större andel i det finlandssvenska materialet än i det sverigesvenska (ca 8 % mot 3 %), men typiskt för båda materialen är hög kollokationsgrad (”kollokation” avser par eller grupper av ord som uppträder oftare tillsammans än de statiskt sett skulle göra vid helt slumpmässig förekomst). Största delen av mottagarbeläggen utgörs av fraser av typen ”ge arbete åt någon, ge eftertryck åt något, ge liv åt något; ägna tid åt något, ägna sitt liv åt något, ägna uppmärksamhet åt något”. De här slutsatserna gäller alltså skriftspråk. I talspråk ser fördelningen annorlunda ut. Typiskt för prepositionen ”åt” är överhuvudtaget hög kollokationsgrad. Det förefaller som om språkanvändarna har tydliga, färdiga mallar för var ”åt” kan komma in. Det enda mönster som verkar helt produktivt, i den meningen att elementen är i stort sett fritt kombinerbara, är kombinationer av verb och åt-fras där åt-frasen avser den som har nytta av något. Att någon utför något för någons räkning verkar överlag kunna uttryckas med prepositionen ”åt”: t.ex. ”tvätta bilen åt pappa, ringa efter en taxi åt kunden”. Till och med belägg av typen ”hon drömde åt honom att bli ordinarie adjunkt” förekommer i någon mån. Konstruktionen är produktiv i båda språkvarieteterna men uppenbart är att konstruktion med mottagare har tolkningsföreträde i vissa fall i finlandssvenskan: ”Filip skrev ett brev åt sin syster” tolkas av sverigesvenskar som att Filip skrev brevet för systerns räkning, medan finlandssvenskar överlag uppenbarligen tolkar det som att Filip skrev till sin syster, att systern var mottagare av brevet. Ungefär 20 % av alla belägg i båda materialen representerar fall där ”åt” utgör partikel. Verb och ”åt” är närmare förbundna med varandra än när ”åt” utgör normal preposition. Exempel på partikelbelägg är ”han kom inte åt strömbrytaren, det gick åt mängder med saft, landet får dra åt svångremmen, de roffade åt sig de bästa platserna”. Också partikelmaterialet ser på ett generellt plan väldigt lika ut i båda språkvarieteterna. Den största skillnaden uppvisar den reflexiva typen ”roffa åt sig”. Medan typen är mycket homogen i det sverigesvenska materialet är variationen större i det finlandsvenska. Dels uppträder fler verb i kombinationen (han köpte åt sig ett par jeans), dels vacklar ordföljden (han nappade åt sig ett paraply ~ han nappade ett paraply åt sig). Att ”åt” används mer i vissa funktioner i finlandsvenskan brukar förklaras med påverkan från finskans allativ (ändelsen -lle: hän antoi kirjan Astalle > hon gav en bok åt Asta). Allt tyder dock på att den finlandssvenska åt-användningen delvis är en relikt. I äldre sverigesvenska källor träffar man på ”åt” i sådana kontexter som numera är typiska för finlandsvenskan. Det finlandssvenska språkområdet ligger ute i periferin i relation till det språkliga centrum som förändringar sprider sig från (för svenskans del främst Stockholmstrakten) och typiskt för perifera områden är att de uppvisar ålderdomliga drag också när inga kontaktfenomen spelar in. Allativen kan naturligtvis ha bidragit till att bevara användningen av ”åt” i finlandssvenskan. Att det är just ”åt” som används” beror antagligen på att prepositionen har flest funktioner gemensamt med allativen rent kognitivt om man jämför med de betydligt mer frekventa prepositionerna ”till” och ”för”. Uppenbart är också att åt-användningen därtill lever sitt eget liv i finlandssvenskan. I vissa varieteter av finlandssvenska kan man t.ex. höra yttranden av typ ”alla fiskarna dog åt dom”. Som språklig enskildhet har det ingen finsk förebild med allativ. Yttrandet är ett exempel på töjning av en svensk konstruktion. Modell finns dels i det mönster där åt avser den som har nytta eller skada av något, dels i relationell användning av ”åt”: han är hantlangare åt Eriksson ~ han är Erikssons hantlangare. Vid språkkontakt är det överlag konstruktioner som har förebild i det låntagande språket som lånas in från det långivande språket, medan konstruktioner som saknar förebild är betydligt mindre benägna att vinna insteg.

Continuous after-the-fact leakage-resilient eCK-secure key exchange

Security models for two-party authenticated key exchange (AKE) protocols have developed over time to capture the security of AKE protocols even when the adversary learns certain secret values. Increased granularity of security can be modelled by considering partial leakage of secrets in the manner of models for leakage-resilient cryptography, designed to capture side-channel attacks. In this work, we use the strongest known partial-leakage-based security model for key exchange protocols, namely continuous after-the-fact leakage eCK (CAFL-eCK) model. We resolve an open problem by constructing the first concrete two-pass leakage-resilient key exchange protocol that is secure in the CAFL-eCK model.

Moments of flux in intermediary liability for copyright infringement

This chapter provides an overview of a recent shift in regulatory strategies to address copyright infringement toward enlisting the assistance of general purpose Internet Service Providers. In Australia, the High Court held in 2012 that iiNet, a general purpose ISP, had no legal duty to police what its subscribers did with their internet connections. We provide an overview of three recent developments in Australian copyright law since that decision that demonstrate an emerging shift in the way that obligations are imposed on ISPs to govern the actions of their users without relying on secondary liability. The first is a new privately negotiated industry code that introduces a 'graduated response' system that requires ISPs to pass on warnings to subscribers who receive allegations of infringement. The second involves a recent series of Federal Court cases where rightsholders made a partially successful application to require ISPs to hand over the identifying details of subscribers whose households are alleged to have infringed copyright. The third is a new legislative scheme that will require ISPs to block access to foreign websites that 'facilitate' infringement. We argue that these shifts represent a greater sophistication in approaches to enrolling general purpose intermediaries in the regulatory project. We also suggest that these shifts represent a potentially disturbing trend towards enforcement of copyright law in a way that does not provide strong safeguards for the legitimate constitutional due process interests of users. We conclude with a call for greater attention and research to better understand how intermediaries make decisions when governing the conduct of users, how those decisions may be influenced by both state and non-state actors, and how the rights of individuals to due process can be adequately protected.

Packed bed bioreactor for the isolation and expansion of placental-derived Mesenchymal Stromal Cells

Large numbers of Mesenchymal stem/stromal cells (MSCs) are required for clinical relevant doses to treat a number of diseases. To economically manufacture these MSCs, an automated bioreactor system will be required. Herein we describe the development of a scalable closed-system, packed bed bioreactor suitable for large-scale MSCs expansion. The packed bed was formed from fused polystyrene pellets that were air plasma treated to endow them with a surface chemistry similar to traditional tissue culture plastic. The packed bed was encased within a gas permeable shell to decouple the medium nutrient supply and gas exchange. This enabled a significant reduction in medium flow rates, thus reducing shear and even facilitating single pass medium exchange. The system was optimised in a small-scale bioreactor format (160 cm2) with murine-derived green fluorescent protein-expressing MSCs, and then scaled-up to a 2800 cm2 format. We demonstrated that placental derived MSCs could be isolated directly within the bioreactor and subsequently expanded. Our results demonstrate that the closed system large-scale packed bed bioreactor is an effective and scalable tool for large-scale isolation and expansion of MSCs.

The Benefits Planner: Improved Work Incentives in Social Security Disability Insurance Program - Changes Will Make Work More Attractive to SSDI Recipients

This newsletter will provide valuable information on how work for persons with disabilities effects government benefits, with an emphasis on the Supplemental Security Income (SSI) and Social Security Disability Insurance (SSDI) work incentives. Each newsletter will contribute to an ongoing dialogue on topics related to benefits and work.

The Benefits Planner: New York Implements Medicaid Buy-In Program - Program Allows Individuals With Disabilities to Work and Keep Medicaid

This newsletter will provide valuable information on how work for persons with disabilities effects government benefits, with an emphasis on the Supplemental Security Income (SSI) and Social Security Disability Insurance (SSDI) work incentives. Each newsletter will contribute to an ongoing dialogue on topics related to benefits and work.

Should the 40-year-old practice of releasing virulent myxoma virus to control rabbits (Oryctolagus cuniculus) be continued?

Release of virulent myxoma virus has been a key component of rabbit-control operations in Queensland, Australia, since the 1960s but its use rests on anecdotal reports. During a routine operation to release virulent myxoma virus we found no evidence to support the continued regular use of the technique in south-west Queensland. Radio-tagged rabbits inoculated with virulent myxoma virus contracted the disease but failed to pass enough virus to other rabbits to spread the disease. Rabbits with clinical signs of myxomatosis that were shot were infected with field strain derived from the original laboratory strain released in 1950 rather than the virulent strain that has been released annually. There was no change in rabbit survival or abundance caused by the release. Nevertheless, the release of virulent virus may be useful against isolated pockets of rabbits mainly because field strains are less likely to be present. Such pockets are more common now that rabbit haemorrhagic disease virus is established in Queensland.

A simple firing delay control circuit for bridge converters

A simple ramp control firing circuit, suitable for use with fully controlled, line-commutated thyristor bridge circuits, is discussed here. This circuit uses very few components and generates the synchronized firing pulses in a simple way. It operates from a single 15 V Supply and has an inherent pulse inhibit facility. This circuit provides the synchronized firing pulses for both thyristors of the same limb in a bridge. To ensure reliability, wide triggering pulses are used, which are modulated to pass through the pulse transformers1 and demodulated before being fed to the thyristor gates. The use of throe such circuits only for a three-phase bridge is discussed.

Mitä autismin kirjon opiskelijat oppivat valmentavassa koulutuksessa

The purpose of this research was to evaluate the special vocational training programme, which aimed at enhancing the pupils with autism spectrum to prepare themselves for work and independent life. The vocational training programme is based on TEACCH (Treatment and Education of Autistic and Related Communication handicapped CHildren), which takes into account the autism spectrum disorders and autistic behaviour. TEACCH is based on the principles of structured teaching, functional teaching and preparation training for work and independent life. The TEACCH has been adapted to Finnish society and the educational system. Treatment programmes were individually designed for each student´s educational needs. There is also an important role for the AAPEP rating scale (Adolescent and Adult Psychoeducational Profile). The AAPEP has been the major tool for planning and following the courses. The AAPEP is an assessment instrument designed by the TEACCH programme, and it is used to provide an evaluation of current and potential skills. The AAPEP contains three scales: a direct observation scale, a home scale and a school / work scale. The AAPEP includes six test variables: vocational skills, independent functions, functional communication, interpersonal behaviour, vocational behaviour and leisure skills; these are evaluated at three levels: pass, emerge and fail. The subjects were 49 students (65% male and 35 % female) with autism spectrum, who have been followed and tested several times, also one year after the vocational training. The design is therefore a longitudinal one. The research data were collected 1997-2004 using the AAPEP rating scales. The teachers have used the AAPEP scales and the codings have been checked by the researcher. The results of the principal component analysis (PCA) suggested that the structure of AAPEP rating scales works quite well as a hypothesis. The factor structure of the scales of the AAPEP was almost the same in these data as in the original publications. The learning-and-changes results showed that learning is a slow process, but that there were also intended changes in several AAPEP areas. The Cohen´s kappa was used as an effect-size measure and the most important result of this research showed that the student´s skills were developing on a school / work scale; vocational skills variable (0,34), vocational behaviour variable (0,28), leisure skills variable (0,26) and on a direct observation scale; interpersonal behaviour variable (0,21). On a home scale skills of some students were developing negatively and also that effect-size was small. The results showed that the students´ vocational skills and vocational behaviour will continue to develop after school in many areas. There were differences between scales. The result of this research shows that the student´s skills were developing significantly in 3 of 48 variables on a direct observation scale and also on a home scale. On a school / work scale student´s skills were developing significantly in 17 of 48 variables. This result implies that students can do the work without extra assistance if there exist continuing supports for the skills after the vocational training. The fully independent life of students will be difficult, because their independent functions, functional communications and leisure skills regressed after the schooling. This seems to indicate that they will not manage their daily life without support. The students and their parents said that the treatment programmes were individually designed for each student s educational needs, and that they were satisfied with the programmes and services. Generally, it can be concluded that vocational special education can be developed for pupils with autistic syndrome and the detailed teaching can be done using TEACCH principles and applying the tool of AAPEP.

The mechanisms of human renal epithelial cell modulation of autologous dendritic cell phenotype and function

Proximal tubule epithelial cells (PTEC) of the kidney line the proximal tubule downstream of the glomerulus and play a major role in the re-absorption of small molecular weight proteins that may pass through the glomerular filtration process. In the perturbed disease state PTEC also contribute to the inflammatory disease process via both positive and negative mechanisms via the production of inflammatory cytokines which chemo-attract leukocytes and the subsequent down-modulation of these cells to prevent uncontrolled inflammatory responses. It is well established that dendritic cells are responsible for the initiation and direction of adaptive immune responses. Both resident and infiltrating dendritic cells are localised within the tubulointerstitium of the renal cortex, in close apposition to PTEC, in inflammatory disease states. We previously demonstrated that inflammatory PTEC are able to modulate autologous human dendritic cell phenotype and functional responses. Here we extend these findings to characterise the mechanisms of this PTEC immune-modulation using primary human PTEC and autologous monocyte-derived dendritic cells (MoDC) as the model system. We demonstrate that PTEC express three inhibitory molecules: (i) cell surface PD-L1 that induces MoDC expression of PD-L1; (ii) intracellular IDO that maintains the expression of MoDC CD14, drives the expression of CD80, PD-L1 and IL-10 by MoDC and inhibits T cell stimulatory capacity; and (iii) soluble HLA-G (sHLA-G) that inhibits HLA-DR and induces IL-10 expression by MoDC. Collectively the results demonstrate that primary human PTEC are able to modulate autologous DC phenotype and function via multiple complex pathways. Further dissection of these pathways is essential to target therapeutic strategies in the treatment of inflammatory kidney disorders.

Political feminism: Activist art in Australia in 2015

Brisbane-based artist and Founding Co-Director of LEVEL artist run initiative Courtney Coombs discusses feminist activist art practice in Australia. Recent discussions both in the art world and beyond have increased the profile and demystified the notion of feminism in the twenty-first century, and the term has once again become integrated into mainstream discussion internationally and in Australia. Now that pop music star Taylor Swift has declared herself a feminist, you could be persuaded that the 'f' word has finally become socially acceptable. However, while many artists have adopted the feminist label across the country, it often feels like feminism has become a lifestyle choice rather than a political one. When the badge is so readily worn by many, society can be fooled into thinking that there is no more work to be done. With the 'f' word once again acceptable while the 'p' word (patriarchy) remains so pass , how are artists responding to the changed conditions but continued imposition of what bell hooks has described as the 'imperialist white supremacist capitalist patriarchy'?

Common SNPs explain a large proportion of the heritability for human height

SNPs discovered by genome-wide association studies (GWASs) account for only a small fraction of the genetic variation of complex traits in human populations. Where is the remaining heritability? We estimated the proportion of variance for human height explained by 294,831 SNPs genotyped on 3,925 unrelated individuals using a linear model analysis, and validated the estimation method with simulations based on the observed genotype data. We show that 45% of variance can be explained by considering all SNPs simultaneously. Thus, most of the heritability is not missing but has not previously been detected because the individual effects are too small to pass stringent significance tests. We provide evidence that the remaining heritability is due to incomplete linkage disequilibrium between causal variants and genotyped SNPs, exacerbated by causal variants having lower minor allele frequency than the SNPs explored to date.

Design and assessment of weirs for fish passage under drowned conditions

In aquatic systems, in-stream structures such as dams, weirs and road crossings can act as barriers to fish movement along waterways. There is a growing array of technological fish-pass solutions for the movement of fish across large structures such as weirs and dams. However, most existing weir structures lack dedicated fishways, and fish often have to rely on drowned conditions to move upstream. In order to assess the adequacy of a given or proposed weir for upstream fish passage under drowned conditions, it is necessary to determine, firstly, the hydraulic properties of the drowned weir with respect to the requirements of the fish community and, secondly, the duration and timing of drowning flows with respect to the hydrograph for the site and the likely timing of fish movements. This paper primarily addresses the first issue. A computer program has been developed and incorporated in a simple-to-operate spreadsheet for the determination of the hydraulic characteristics of a drowned weir which are important to fish movement. The program is based on a theoretical analysis of drowned weirs and subsequent extensive verification in laboratory experiments. Inputs to the program include site information comprising channel cross-section data, channel slope, and channel roughness, and weir information comprising weir height and the required minimum drowned depth over the weir for migrating fish passage. The program then calculates the flow rate at which the required level of drowning occurs, the velocity characteristics above the weir (including transverse distributions), and flow depths and velocities upstream and downstream of the weir. The paper discusses (briefly) the theoretical background of the program and its experimental verification. A case study is then presented that illustrates the use of the program in the field to assess fish passage opportunities at an existing weir and to develop a case for retrofitting a fishway. Some discussion is also provided on the contribution of a modelled drownout volume to the assessment of how significant a barrier a weir is to fish passage. It is shown that the program is an important new additional tool in the assessment of the adequacy of weir structures in providing for fish movement and informing associated fish passage solutions. (C) 2011 Elsevier B.V. All rights reserved.

Characterization of Actinobacteria Degrading and Tolerating Organic Pollutants

Species of the genera Rhodococcus, Gordonia and Mycobacterium are known as degraders of recalcitrant pollutants. These bacteria are good survivors in harsh environments. Due to such properties these organisms are able to occupy a wide range of environmental niches. The members of these taxa have been suggested as tools for biotechnical applications such as bioremediation and biosynthesis. At the same time several of the species are known as opportunistic human pathogens. Therefore, the detailed characterization of any isolate that has potential for biotechnological applications is very important. This thesis deals with several corynebacterial strains originating from different polluted environments: soil, water-damaged indoor walls, and drinking water distribution systems. A polyphasic taxonomic approach was applied for characterization of the isolates. We found that the strains degrading monoaromatic compounds belonged to Rhodococcus opacus, a species that has not been associated with any health problem. The taxonomic position of strain B293, used for many years in degradation research under different names, was clarified. We assigned it to the species Gordonia polyisoprenivorans. This species is classified under European Biohazard grouping 1, meaning that it is not considered a health hazard for humans. However, there are reports of catheter-associated bacteraemia caused by G. polyisoprenivorans. Our results suggested that the ability of the organism to grow on phthalate esters, used as softeners in medical plastics, may be associated with the colonization of catheters and other devices. In this thesis Mycobacterium lentiflavum, a new emerging opportunistic human pathogen, was isolated from biofilms growing in public drinking water distribution systems. Our report on isolation of M. lentiflavum from water supplies is the second report on this species from drinking water systems, which may thus constitute a reservoir of M. lentiflavum. Automated riboprinting was evaluated for its applicability in rapidly identifying environmental mycobacteria. The technique was found useful in the characterization of several species of rapidly and slowly growing environmental mycobacteria. The second aspect of this thesis refers to characterization of the degradation and tolerance power of several R. opacus, M. murale and G. polyisoprenivorans strains. R. opacus GM-14 utilizes a wide range of aromatic substrates, including benzene, 15 different halobenzenes, 18 phenols and 7 benzoates. This study revealed the high tolerance of R. opacus strains toward toxic hydrophobic compounds. R. opacus GM-14 grew in mineral medium to which benzene or monochlorobenzene was added in amounts of 13 or 3 g l-1, respectively. R. opacus GM-29 utilized toluene and benzene for growth. Strain GM-29 grew in mineral medium with 7 g l-1 of liquid toluene or benzene as the sole carbon source, corresponding to aqueous concentrations of 470 and 650 mg l-1, respectively. Most organic solvents, such as toluene and benzene, due to their high level of hydrophobicity, pass through the bacterial membrane, causing its disintegration. In this thesis the mechanisms of adaptation of rhodococci to toxic hydrophobic compounds were investigated. The rhodococcal strains increased the level of saturation of their cellular fatty acids in response to challenge with phenol, chlorophenol, benzene, chlorobenzene or toluene. The results indicated that increase in the saturation level of cellular fatty acids, particularly that in tuberculostearic acid, is part of the adaptation mechanism of strains GM-14 and GM-29 to the presence of toxic hydrophobic compounds.