title: Computerised tomography indices of raised intracranial pressure and traumatic brain injury severity in a New Zealand sample

authors: Barker-Collo, Suzanne

abstract: After traumatic brain injury (TBI) complex cellular and biochemical processes occur¹ including changes in blood flow and oxygenation of the brain; cerebral swelling; and raised intracranial pressure (ICP).² This can dramatically worsen the damage³ and contributes to mortality.

text: Computerised tomography indices of raised intracranial pressure and traumatic brain injury severity in a New Zealand sample After traumatic brain injury (TBI) complex cellular and biochemical processes occur¹ including changes in blood flow and oxygenation of the brain; cerebral swelling; and raised intracranial pressure (ICP).² This can dramatically worsen the damage³ and contributes to mortality.

year: 2012

title: Biembeddings of cycle systems using integer Heffter arrays

authors: Cavenagh, Nicholas J.

subjects: mathematics

abstract: In this paper, we use constructions of Heffter arrays to verify the existence of face 2‐colorable embeddings of cycle decompositions of the complete graph. Specifically, for n ≡ 1 (mod 4) and k ≡3(mod 4), n k ≫ ⩾ 7 and when n ≡ 0(mod 3) then k ≡ 7(mod 12), there exist face 2-colorable embeddings of the complete graph K₂ₙₖ₊₁ onto an orientable surface where each face is a cycle of a fixed length k. In these embeddings the vertices of K₂ₙₖ₊₁ will be labeled with the elements of Z₂ₙₖ₊₁ in such a way that the group, (Z₂ₙₖ₊₁, +) acts sharply transitively on the vertices of the embedding. This result is achieved by verifying the existence of nonequivalent Heffter arrays, H (n ; k), which satisfy the conditions: (1) for each row and each column the sequential partial sums determined by the natural ordering must be distinct modulo 2nk + 1; (2) the composition of the natural orderings of the rows and columns is equivalent to a single cycle permutation on the entries in the array. The existence of Heffter arrays H (n ; k) that satisfy condition (1) was established earlier in Burrage et al. and in this current paper, we vary this construction and show, for k ⩾ 11, that there are at least (n − 2)[((k − 11)/4)!/ ]² such nonequivalent H (n ; k) that satisfy both conditions (1) and (2).

text: Biembeddings of cycle systems using integer Heffter arrays In this paper, we use constructions of Heffter arrays to verify the existence of face 2‐colorable embeddings of cycle decompositions of the complete graph. Specifically, for n ≡ 1 (mod 4) and k ≡3(mod 4), n k ≫ ⩾ 7 and when n ≡ 0(mod 3) then k ≡ 7(mod 12), there exist face 2-colorable embeddings of the complete graph K₂ₙₖ₊₁ onto an orientable surface where each face is a cycle of a fixed length k. In these embeddings the vertices of K₂ₙₖ₊₁ will be labeled with the elements of Z₂ₙₖ₊₁ in such a way that the group, (Z₂ₙₖ₊₁, +) acts sharply transitively on the vertices of the embedding. This result is achieved by verifying the existence of nonequivalent Heffter arrays, H (n ; k), which satisfy the conditions: (1) for each row and each column the sequential partial sums determined by the natural ordering must be distinct modulo 2nk + 1; (2) the composition of the natural orderings of the rows and columns is equivalent to a single cycle permutation on the entries in the array. The existence of Heffter arrays H (n ; k) that satisfy condition (1) was established earlier in Burrage et al. and in this current paper, we vary this construction and show, for k ⩾ 11, that there are at least (n − 2)[((k − 11)/4)!/ ]² such nonequivalent H (n ; k) that satisfy both conditions (1) and (2).

year: 2020

title: The Effects of Contaminated Rena Sediments on Juvenile Paua (Haliotis iris)

authors: McSweeney, Caleb S.

subjects: contamiant

abstract: The grounding of the MV Rena on Otaiti resulted in the release of heavy fuel oil and container debris contaminants into the surrounding environments including the rocky shores of the adjacent Mōtītī Island. This is the habitat where significant populations of benthic paua reside. Paua (Haliotis iris) are a staple and consistent food source for Mōtītī Island. Being an offshore island with no amenities, Mōtītī Island residents are reliant on the ocean as a pataka kai (food cupboard) and are therefore acutely aware of environmental influences to the harvest of kaimoana.
This thesis aimed to address concerns relating to the effects of contaminated boundary layer water emanating from contaminated ‘Rena’ sediment on juvenile paua. Research was focused in two areas: 1) the sublethal behavioural effects of contaminated Rena sediment to Paua and 2) the accumulation of trace metals in the edible tissue and viscera mass. The experiments were carried out with the use of a close circuit aquaria in a laboratory environment, followed by a field experiment.
In all experiments, paua in control treatments were healthy by comparison to paua exposed to treatments with Rena contaminated sediments and copper as judged by survivorship and behaviour. The most likely cause of of behavioural aberrations and mortality observed was deemed to be copper as demonstrated by Diffusive Gradient in thin film (DGT) and ambient water analyses in both experiments. Copper that is bioavailable can increase quickly in the edible tissue and viscera mass as was identified as the visceral mass of Rena and copper exposed paua had a higher mean concentration of this and other trace metals.
On Otaiti, the effects to paua from the Rena ship wreck and lost container contents, know to include a medly of metals and other contaminants, is not likely to be limited to copper alone. Results demosntrate the relevance of examining the effects of water borne contaminated plumes emanating from complex mixtures of contaminants. This is rarely done in ecotoxicological studies which tend to focus on individual contaminant compounds.

text: The Effects of Contaminated Rena Sediments on Juvenile Paua (Haliotis iris) The grounding of the MV Rena on Otaiti resulted in the release of heavy fuel oil and container debris contaminants into the surrounding environments including the rocky shores of the adjacent Mōtītī Island. This is the habitat where significant populations of benthic paua reside. Paua (Haliotis iris) are a staple and consistent food source for Mōtītī Island. Being an offshore island with no amenities, Mōtītī Island residents are reliant on the ocean as a pataka kai (food cupboard) and are therefore acutely aware of environmental influences to the harvest of kaimoana.
This thesis aimed to address concerns relating to the effects of contaminated boundary layer water emanating from contaminated ‘Rena’ sediment on juvenile paua. Research was focused in two areas: 1) the sublethal behavioural effects of contaminated Rena sediment to Paua and 2) the accumulation of trace metals in the edible tissue and viscera mass. The experiments were carried out with the use of a close circuit aquaria in a laboratory environment, followed by a field experiment.
In all experiments, paua in control treatments were healthy by comparison to paua exposed to treatments with Rena contaminated sediments and copper as judged by survivorship and behaviour. The most likely cause of of behavioural aberrations and mortality observed was deemed to be copper as demonstrated by Diffusive Gradient in thin film (DGT) and ambient water analyses in both experiments. Copper that is bioavailable can increase quickly in the edible tissue and viscera mass as was identified as the visceral mass of Rena and copper exposed paua had a higher mean concentration of this and other trace metals.
On Otaiti, the effects to paua from the Rena ship wreck and lost container contents, know to include a medly of metals and other contaminants, is not likely to be limited to copper alone. Results demosntrate the relevance of examining the effects of water borne contaminated plumes emanating from complex mixtures of contaminants. This is rarely done in ecotoxicological studies which tend to focus on individual contaminant compounds.

year: 2015