scholarly journals Shear behavior of DFDP-1 borehole samples from the Alpine Fault, New Zealand, under a wide range of experimental conditions

2015 ◽  
Vol 104 (6) ◽  
pp. 1523-1535 ◽  
Author(s):  
Matt J. Ikari ◽  
Sebastian Trütner ◽  
Brett M. Carpenter ◽  
Achim J. Kopf
2021 ◽  
Author(s):  
Carolyn Boulton ◽  
D Moore ◽  
D Lockner ◽  
V Toy ◽  
John Townend ◽  
...  

Principal slip zone gouges recovered during the Deep Fault Drilling Project (DFDP-1), Alpine Fault, New Zealand, were deformed in triaxial friction experiments at temperatures, T, of up to 350°C, effective normal stresses, σn′, of up to 156 MPa, and velocities between 0.01 and 3 μm/s. Chlorite/white mica-bearing DFDP-1A blue gouge, 90.62 m sample depth, is frictionally strong (friction coefficient, μ, 0.61-0.76) across all experimental conditions tested (T = 70-350°C, σn′ = 31.2-156 MPa); it undergoes a transition from positive to negative rate dependence as T increases past 210°C. The friction coefficient of smectite-bearing DFDP-1B brown gouge, 128.42 m sample depth, increases from 0.49 to 0.74 with increasing temperature and pressure (T = 70-210°C, σn′ = 31.2-93.6 MPa); the positive to negative rate dependence transition occurs as T increases past 140°C. These measurements indicate that, in the absence of elevated pore fluid pressures, DFDP-1 gouges are frictionally strong under conditions representative of the seismogenic crust.


2021 ◽  
Author(s):  
◽  
Kathy Barbara Rose Hill

<p>New Zealand, because of its wide range of habitats and rapidly changing, well-studied palaeohistory provides an excellent opportunity to investigate the impact of earth processes on the distribution of taxa. There are now a variety of studies on plants that investigate such patterns, and a growing number of studies on animal taxa. Most studies have supported the hypothesis that current patterns of distribution of New Zealand taxa were created by dispersal, mediated by landscape and climatic conditions over time, and have contradicted the panbiogeographic hypothesis that explained distributions via vicariant landscape changes such as lateral displacement along the Alpine Fault. This thesis presents a detailed phylogeographic history of a widespread, endemic New Zealand cicada, Maoricicada campbelli, that is abundant throughout much of the South Island and is also found in the central volcanic plateau of the North Island. Mitochondrial DNA sequences of 223 individuals from 70 populations of M. campbelli were studied using both traditional phylogenetic methods and nested clade analysis (NCA). As found in a previous study of 35 M. campbelli individuals, geographic structuring was strong, with two main clades (North Island+northern South Island versus Otago) representing diverse lineages that may in fact be different species. Population structuring within the northern South Island clade suggested that the central South Island was mostly uninhabitable during glacial periods and demonstrated a sister-group relationship between northern and southern Southern Alps populations to the exclusion of the more central Southern Alps populations. Population histories estimated from NCA support the hypothesis that most M. campbelli populations were formed through dispersal rather than via fragmentation or Alpine Fault vicariance. Three areas of ring-species-like secondary contact were found between the Otago and northern South Island clades, between lineages that had been isolated for approximately 2.3my. Further study is predicted to confirm the presence of additional suspected contact zones, and will demonstrate whether the different lineages are reproductively isolated or hybridising at these areas of secondary contact.</p>


2021 ◽  
Author(s):  
◽  
Kathy Barbara Rose Hill

<p>New Zealand, because of its wide range of habitats and rapidly changing, well-studied palaeohistory provides an excellent opportunity to investigate the impact of earth processes on the distribution of taxa. There are now a variety of studies on plants that investigate such patterns, and a growing number of studies on animal taxa. Most studies have supported the hypothesis that current patterns of distribution of New Zealand taxa were created by dispersal, mediated by landscape and climatic conditions over time, and have contradicted the panbiogeographic hypothesis that explained distributions via vicariant landscape changes such as lateral displacement along the Alpine Fault. This thesis presents a detailed phylogeographic history of a widespread, endemic New Zealand cicada, Maoricicada campbelli, that is abundant throughout much of the South Island and is also found in the central volcanic plateau of the North Island. Mitochondrial DNA sequences of 223 individuals from 70 populations of M. campbelli were studied using both traditional phylogenetic methods and nested clade analysis (NCA). As found in a previous study of 35 M. campbelli individuals, geographic structuring was strong, with two main clades (North Island+northern South Island versus Otago) representing diverse lineages that may in fact be different species. Population structuring within the northern South Island clade suggested that the central South Island was mostly uninhabitable during glacial periods and demonstrated a sister-group relationship between northern and southern Southern Alps populations to the exclusion of the more central Southern Alps populations. Population histories estimated from NCA support the hypothesis that most M. campbelli populations were formed through dispersal rather than via fragmentation or Alpine Fault vicariance. Three areas of ring-species-like secondary contact were found between the Otago and northern South Island clades, between lineages that had been isolated for approximately 2.3my. Further study is predicted to confirm the presence of additional suspected contact zones, and will demonstrate whether the different lineages are reproductively isolated or hybridising at these areas of secondary contact.</p>


2021 ◽  
Author(s):  
Carolyn Boulton ◽  
D Moore ◽  
D Lockner ◽  
V Toy ◽  
John Townend ◽  
...  

Principal slip zone gouges recovered during the Deep Fault Drilling Project (DFDP-1), Alpine Fault, New Zealand, were deformed in triaxial friction experiments at temperatures, T, of up to 350°C, effective normal stresses, σn′, of up to 156 MPa, and velocities between 0.01 and 3 μm/s. Chlorite/white mica-bearing DFDP-1A blue gouge, 90.62 m sample depth, is frictionally strong (friction coefficient, μ, 0.61-0.76) across all experimental conditions tested (T = 70-350°C, σn′ = 31.2-156 MPa); it undergoes a transition from positive to negative rate dependence as T increases past 210°C. The friction coefficient of smectite-bearing DFDP-1B brown gouge, 128.42 m sample depth, increases from 0.49 to 0.74 with increasing temperature and pressure (T = 70-210°C, σn′ = 31.2-93.6 MPa); the positive to negative rate dependence transition occurs as T increases past 140°C. These measurements indicate that, in the absence of elevated pore fluid pressures, DFDP-1 gouges are frictionally strong under conditions representative of the seismogenic crust.


2019 ◽  
Author(s):  
Christopher John ◽  
Greg M. Swain ◽  
Robert P. Hausinger ◽  
Denis A. Proshlyakov

2-Oxoglutarate (2OG)-dependent dioxygenases catalyze C-H activation while performing a wide range of chemical transformations. In contrast to their heme analogues, non-heme iron centers afford greater structural flexibility with important implications for their diverse catalytic mechanisms. We characterize an <i>in situ</i> structural model of the putative transient ferric intermediate of 2OG:taurine dioxygenase (TauD) by using a combination of spectroelectrochemical and semi-empirical computational methods, demonstrating that the Fe (III/II) transition involves a substantial, fully reversible, redox-linked conformational change at the active site. This rearrangement alters the apparent redox potential of the active site between -127 mV for reduction of the ferric state and 171 mV for oxidation of the ferrous state of the 2OG-Fe-TauD complex. Structural perturbations exhibit limited sensitivity to mediator concentrations and potential pulse duration. Similar changes were observed in the Fe-TauD and taurine-2OG-Fe-TauD complexes, thus attributing the reorganization to the protein moiety rather than the cosubstrates. Redox difference infrared spectra indicate a reorganization of the protein backbone in addition to the involvement of carboxylate and histidine ligands. Quantitative modeling of the transient redox response using two alternative reaction schemes across a variety of experimental conditions strongly supports the proposal for intrinsic protein reorganization as the origin of the experimental observations.


2008 ◽  
Vol 61 ◽  
pp. 362-367
Author(s):  
H.M. Harman ◽  
N.W. Waipara ◽  
C.J. Winks ◽  
L.A. Smith ◽  
P.G. Peterson ◽  
...  

Bridal creeper is a weed of natural and productive areas in the northern North Island of New Zealand A classical biocontrol programme was initiated in 20052007 with a survey of invertebrate fauna and pathogens associated with the weed in New Zealand Although bridal creeper was attacked by a wide range of generalist invertebrates their overall damage affected


2021 ◽  
Vol 22 (15) ◽  
pp. 7879
Author(s):  
Yingxia Gao ◽  
Yi Zheng ◽  
Léon Sanche

The complex physical and chemical reactions between the large number of low-energy (0–30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.


Author(s):  
Baoliang Chen ◽  
Peng Liu ◽  
Feiyun Xiao ◽  
Zhengshi Liu ◽  
Yong Wang

Quantitative assessment is crucial for the evaluation of human postural balance. The force plate system is the key quantitative balance assessment method. The purpose of this study is to review the important concepts in balance assessment and analyze the experimental conditions, parameter variables, and application scope based on force plate technology. As there is a wide range of balance assessment tests and a variety of commercial force plate systems to choose from, there is room for further improvement of the test details and evaluation variables of the balance assessment. The recommendations presented in this article are the foundation and key part of the postural balance assessment; these recommendations focus on the type of force plate, the subject’s foot posture, and the choice of assessment variables, which further enriches the content of posturography. In order to promote a more reasonable balance assessment method based on force plates, further methodological research and a stronger consensus are still needed.


Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 255
Author(s):  
Marie Tahon ◽  
Silvio Montresor ◽  
Pascal Picart

Digital holography is a very efficient technique for 3D imaging and the characterization of changes at the surfaces of objects. However, during the process of holographic interferometry, the reconstructed phase images suffer from speckle noise. In this paper, de-noising is addressed with phase images corrupted with speckle noise. To do so, DnCNN residual networks with different depths were built and trained with various holographic noisy phase data. The possibility of using a network pre-trained on natural images with Gaussian noise is also investigated. All models are evaluated in terms of phase error with HOLODEEP benchmark data and with three unseen images corresponding to different experimental conditions. The best results are obtained using a network with only four convolutional blocks and trained with a wide range of noisy phase patterns.


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