title: Bovine mastitis and ecology of Streptococcus uberis

authors: Pryor, Shona Marie

subjects: Bovine

abstract: Bovine mastitis caused by Streptococcus uberis is a common problem in pasture-based dairying systems. This study examines both the ecology of S. uberis and infection of the bovine mammary gland on a New Zealand dairy farm. Initially, the REP-PCR strain typing method was developed and the potential of MALDI-TOF mass spectrometry evaluated as a strain typing method. While strain-specific mass spectra were obtained with MALDI-TOF mass spectrometry, the irreproducibility of spectra was its major downfall. With further work, this rapid method could be very useful for strain typing S. uberis on a large scale. Using optimised REP-PCR and anchored typing methods, multiple S. uberis strains were isolated and strain typed from the dairy environment, including farm races and paddocks, faeces, teat skin, the cow body and from intramammary infections. High strain diversity was observed in all sampled locations; however, some strains were found at more than one site, suggesting transmission may occur between the environment and cows. The most likely means of S. uberis distribution throughout the dairy farm was via excretion with faeces and, although not all cow faeces contained this pathogen, the gastrointestinal tract of some cows appeared to be colonised by specific strains, resulting in persistent shedding of this bacteria in the faeces.
Infection of the mammary gland is likely to occur through contamination of the teat skin with highly diverse environmental strains of S. uberis. However, only one or two strains are generally found in milk from mastitis cases, suggesting that, although infection may arise from a random or opportunistic event, a strain selection process may take place. Intramammary challenge with multiple strains of S. uberis revealed that selection of a single infective strain can occur within the mammary gland. The predominance of one strain over others may be related to production of virulence factors allowing enhanced ability to establish in the gland and evade the immune response, or due to direct competition between strains through the production of antimicrobial factors such as bacteriocins. In addition to strain-specific factors, the individual cow and quarter response may play an important role in the development of infection and selection of the infective strain.
Using results from this study, a model of S. uberis strain transmission has been proposed, which includes potential mechanisms of infection and persistence of S. uberis within the mammary gland.

text: Bovine mastitis and ecology of Streptococcus uberis Bovine mastitis caused by Streptococcus uberis is a common problem in pasture-based dairying systems. This study examines both the ecology of S. uberis and infection of the bovine mammary gland on a New Zealand dairy farm. Initially, the REP-PCR strain typing method was developed and the potential of MALDI-TOF mass spectrometry evaluated as a strain typing method. While strain-specific mass spectra were obtained with MALDI-TOF mass spectrometry, the irreproducibility of spectra was its major downfall. With further work, this rapid method could be very useful for strain typing S. uberis on a large scale. Using optimised REP-PCR and anchored typing methods, multiple S. uberis strains were isolated and strain typed from the dairy environment, including farm races and paddocks, faeces, teat skin, the cow body and from intramammary infections. High strain diversity was observed in all sampled locations; however, some strains were found at more than one site, suggesting transmission may occur between the environment and cows. The most likely means of S. uberis distribution throughout the dairy farm was via excretion with faeces and, although not all cow faeces contained this pathogen, the gastrointestinal tract of some cows appeared to be colonised by specific strains, resulting in persistent shedding of this bacteria in the faeces.
Infection of the mammary gland is likely to occur through contamination of the teat skin with highly diverse environmental strains of S. uberis. However, only one or two strains are generally found in milk from mastitis cases, suggesting that, although infection may arise from a random or opportunistic event, a strain selection process may take place. Intramammary challenge with multiple strains of S. uberis revealed that selection of a single infective strain can occur within the mammary gland. The predominance of one strain over others may be related to production of virulence factors allowing enhanced ability to establish in the gland and evade the immune response, or due to direct competition between strains through the production of antimicrobial factors such as bacteriocins. In addition to strain-specific factors, the individual cow and quarter response may play an important role in the development of infection and selection of the infective strain.
Using results from this study, a model of S. uberis strain transmission has been proposed, which includes potential mechanisms of infection and persistence of S. uberis within the mammary gland.

year: 2008

title: Bottom-up propositionalization

authors: Kramer, Stefan

abstract: In this paper, we present a new method for propositionalization that works in a bottom-up, data-driven manner. It is tailored for biochemical databases, where the examples are 2-D descriptions of chemical compounds. The method generates all frequent fragments (i.e., linearly connected atoms) up to a user-specified length. A preliminary experiment in the domain of carcinogenicity predictions showed that bottom-up propositionalization is a promising approach to feature construction from relational data.

text: Bottom-up propositionalization In this paper, we present a new method for propositionalization that works in a bottom-up, data-driven manner. It is tailored for biochemical databases, where the examples are 2-D descriptions of chemical compounds. The method generates all frequent fragments (i.e., linearly connected atoms) up to a user-specified length. A preliminary experiment in the domain of carcinogenicity predictions showed that bottom-up propositionalization is a promising approach to feature construction from relational data.

year: 2000-07

title: Indigenous Peoples and the Protection of Their Secret Knowledge: A Promising Pathway Ahead

authors: Masoni, Claudia

abstract: This work focuses on the intangible, secret aspects of indigenous peoples’ cultures and how such secret information is protected by indigenous guardians or holders. This is because much of indigenous culture is imbued with spiritual significance for indigenous peoples and, consequently, it is not made available to the rest of the community and the world at large.
This thesis examines the reasons why it is important to preserve indigenous cultures and secret practices that today survive in indigenous communities. The thesis demonstrates that secrecy is seen as essential to the preservation of indigenous secret knowledge. Indigenous guardians are responsible for the preservation of the information, and they commonly use secrecy to preserve the knowledge and, when they share it, they choose limited, confidential circumstances to do so. This work argues that it is important to make reasonable space in the existing body of laws which have so far failed to effectively protect indigenous secret practices and information. The case study described in this thesis helps understand how states are currently trying to listen, understand and accommodate indigenous claims brought forward at the national and international fora. The thesis reviews the legal protection currently available to indigenous secret knowledge in national and international law. The first 6 chapters introduce indigenous cultures, holism and indigenous peoples and international law, and chapter 7 describes the New Zealand case Wai 262 and the recommendations given by the Waitangi Tribunal. The remaining chapters analyse indigenous cultures and intellectual property laws, identifying gaps in the existing mechanisms for protection and underlining why, as of today, intellectual property law does not guarantee adequate protection to indigenous secret knowledge. The last chapter analyses the law of breach of confidence as a possible instrument to safeguard indigenous secret information and the duty of care performed by indigenous guardians in preserving such knowledge. It argues that the existing law of confidentiality can usefully evolve to protect cultural secret information as a growing category in its own right and that indigenous secret information can find protection as confidential information.

text: Indigenous Peoples and the Protection of Their Secret Knowledge: A Promising Pathway Ahead This work focuses on the intangible, secret aspects of indigenous peoples’ cultures and how such secret information is protected by indigenous guardians or holders. This is because much of indigenous culture is imbued with spiritual significance for indigenous peoples and, consequently, it is not made available to the rest of the community and the world at large.
This thesis examines the reasons why it is important to preserve indigenous cultures and secret practices that today survive in indigenous communities. The thesis demonstrates that secrecy is seen as essential to the preservation of indigenous secret knowledge. Indigenous guardians are responsible for the preservation of the information, and they commonly use secrecy to preserve the knowledge and, when they share it, they choose limited, confidential circumstances to do so. This work argues that it is important to make reasonable space in the existing body of laws which have so far failed to effectively protect indigenous secret practices and information. The case study described in this thesis helps understand how states are currently trying to listen, understand and accommodate indigenous claims brought forward at the national and international fora. The thesis reviews the legal protection currently available to indigenous secret knowledge in national and international law. The first 6 chapters introduce indigenous cultures, holism and indigenous peoples and international law, and chapter 7 describes the New Zealand case Wai 262 and the recommendations given by the Waitangi Tribunal. The remaining chapters analyse indigenous cultures and intellectual property laws, identifying gaps in the existing mechanisms for protection and underlining why, as of today, intellectual property law does not guarantee adequate protection to indigenous secret knowledge. The last chapter analyses the law of breach of confidence as a possible instrument to safeguard indigenous secret information and the duty of care performed by indigenous guardians in preserving such knowledge. It argues that the existing law of confidentiality can usefully evolve to protect cultural secret information as a growing category in its own right and that indigenous secret information can find protection as confidential information.

year: 2017