title: Identifying Host Species of Dactylanthus taylorii using DNA Barcoding

authors: Parker, Cassarndra Marie

subjects: Dactylanthus

abstract: The population of the endangered endemic holoparasitic plant, Dactylanthus taylorii Hook F. (Balanophoraceae), in Pureora Forest Park was selected as the trial population for developing a method to accurately identify host species using DNA barcoding methods. The marker used was psbA-trnH, and ten samples were able to be successfully identified using the protocol trialed. Of these samples, nine were identified as Pseudopanax arboreus, with one result of Podocarpus totara. The marker used (psbA-trnH) provided adequate levels of variation to discriminate between the host species sequenced in the pilot study. Further work will focus on refining the protocol and trialing a second region for greater resolution of the Pseudopanax species cluster. The method used is relatively simple to employ, and resulted in no mortality of host or tuber. The ability to accurately identify hosts paves the way for the creation of an accurate host list which reflects the true host range and preferences of Dactylanthus taylorii. Globally, few host lists are accurate, and this poses significant challenges for managers. Future work will expand upon this study, collecting host root samples from populations across New Zealand to determine host preferences.

text: Identifying Host Species of Dactylanthus taylorii using DNA Barcoding The population of the endangered endemic holoparasitic plant, Dactylanthus taylorii Hook F. (Balanophoraceae), in Pureora Forest Park was selected as the trial population for developing a method to accurately identify host species using DNA barcoding methods. The marker used was psbA-trnH, and ten samples were able to be successfully identified using the protocol trialed. Of these samples, nine were identified as Pseudopanax arboreus, with one result of Podocarpus totara. The marker used (psbA-trnH) provided adequate levels of variation to discriminate between the host species sequenced in the pilot study. Further work will focus on refining the protocol and trialing a second region for greater resolution of the Pseudopanax species cluster. The method used is relatively simple to employ, and resulted in no mortality of host or tuber. The ability to accurately identify hosts paves the way for the creation of an accurate host list which reflects the true host range and preferences of Dactylanthus taylorii. Globally, few host lists are accurate, and this poses significant challenges for managers. Future work will expand upon this study, collecting host root samples from populations across New Zealand to determine host preferences.

year: 2015

title: Long‐term residual properties and durability of glass fiber reinforced polymer composite exposed to alkaline solution and natural weather for a decade

authors: Ahmad Sawpan, Moyeenuddin

abstract: This paper presents a comprehensive analysis of the residual thermal and mechanical properties of pultruded glass fiber reinforced polymer composite bars following a decade of conditioning in an alkaline solution and exposure to natural weather conditions. The study focuses on evaluating the changes in the glass transition temperature (Tg) of the polymer matrix and its impact on the bar's mechanical performance. The results indicate that the Tg retained approximately 94.7% of its initial value, with the decrease attributed to the plasticizing effect of absorbed water. The flexural modulus, flexural strength, and transverse shear strength were found to retain 91.8%, 77.2%, and 97.3% of their original values, respectively. The reductions in strength and stiffness were primarily attributed to a weakening in the bonding between the fibers and the polymer matrix. Fractographic analysis revealed that the failure of the plasticized and softened polymer matrix contributed to the observed reductions in strength. Interestingly, the short beam shear strength remained relatively unchanged, as the diffusion of water into the core of the bars at ambient temperatures had a minimal effect. This slower water diffusion in the core led to insignificant degradation of the short beam shear strength.

Highlights
○ GFRP bars were exposed to alkaline solution and natural weather for a decade.
○ The water diffusion was a key factor in determining the residual properties of the GFRP bars.
○ The absorbed water plasticises the polymer matrix in GFRP bars.
○ The mechanical property losses in GFRP bars were associated with changes in the matrix property.

text: Long‐term residual properties and durability of glass fiber reinforced polymer composite exposed to alkaline solution and natural weather for a decade This paper presents a comprehensive analysis of the residual thermal and mechanical properties of pultruded glass fiber reinforced polymer composite bars following a decade of conditioning in an alkaline solution and exposure to natural weather conditions. The study focuses on evaluating the changes in the glass transition temperature (Tg) of the polymer matrix and its impact on the bar's mechanical performance. The results indicate that the Tg retained approximately 94.7% of its initial value, with the decrease attributed to the plasticizing effect of absorbed water. The flexural modulus, flexural strength, and transverse shear strength were found to retain 91.8%, 77.2%, and 97.3% of their original values, respectively. The reductions in strength and stiffness were primarily attributed to a weakening in the bonding between the fibers and the polymer matrix. Fractographic analysis revealed that the failure of the plasticized and softened polymer matrix contributed to the observed reductions in strength. Interestingly, the short beam shear strength remained relatively unchanged, as the diffusion of water into the core of the bars at ambient temperatures had a minimal effect. This slower water diffusion in the core led to insignificant degradation of the short beam shear strength.

Highlights
○ GFRP bars were exposed to alkaline solution and natural weather for a decade.
○ The water diffusion was a key factor in determining the residual properties of the GFRP bars.
○ The absorbed water plasticises the polymer matrix in GFRP bars.
○ The mechanical property losses in GFRP bars were associated with changes in the matrix property.

year: 2023-10-09

title: Kuta (Eleocharis sphacelata, Cyperaceae), a locally important and highly valued weaving plant

authors: Wehi, Priscilla M.

subjects: Northland (N.Z.)

abstract: This article introduces and discusses kuta (Eleocharis sphacelata, Cyperaceae), a tall spikerush found on the margins of shallow lakes in New Zealand, which, although often overlooked, is considered in Northland to be a valuable weaving resource.

text: Kuta (Eleocharis sphacelata, Cyperaceae), a locally important and highly valued weaving plant This article introduces and discusses kuta (Eleocharis sphacelata, Cyperaceae), a tall spikerush found on the margins of shallow lakes in New Zealand, which, although often overlooked, is considered in Northland to be a valuable weaving resource.

year: 2006