Modelling transport of larval New Zealand abalone (Haliotis iris) along an open coast

2006 ◽  
Vol 57 (5) ◽  
pp. 519 ◽  
Author(s):  
S. A. Stephens ◽  
N. Broekhuizen ◽  
A. B. Macdiarmid ◽  
C. J. Lundquist ◽  
L. McLeod ◽  
...  
Keyword(s):  
New Zealand ◽  
Larval Dispersal ◽  
Release Site ◽  
High Energy ◽  
Energy Conditions ◽  
Important Species ◽  
Open Coast ◽  
Successful Recruitment ◽  
Starting Point ◽  
Near Shore

The dispersal and transport of larval New Zealand abalone Haliotis iris was simulated using coupled two-dimensional hydrodynamic and Lagrangian particle-trajectory models. The aim was to estimate pelagic larval dispersal potential along the open coast, as a starting point from which basic management questions can be made for this recreationally and commercially important species. Larval dispersal was simulated from representative spawning sites under a range of representative hydrodynamic conditions, including wave-induced circulation cells. Larval presence over near-shore reef habitat declined as the energy of the flow field and corresponding larval dispersal and transport increased. Thus, spawning during high-energy conditions will promote dispersal and transport but reduce successful recruitment on near-shore reefs. This indicates that seeding of the adjacent coast is likely to be sporadic, with existing populations necessarily being somewhat self-recruiting. Results suggest that an ideal management system would ensure that adult populations were maintained at intervals of 10–30 km along the coast to maintain larval supply to areas in between. Dispersal characteristics were specific to the release site, and the simulations suggest that marine reserves can be positioned to accordingly achieve desired functions: for example, optimal choices can be made for seeding areas, recruitment or self-maintaining areas.

scholarly journals Wave and Tidal Controls on Embayment Circulation and Headland Bypassing for an Exposed, Macrotidal Site

2018 ◽  
Vol 6 (3) ◽  
pp. 94 ◽  
Author(s):  
R. McCarroll ◽  
Gerd Masselink ◽  
Nieves Valiente ◽  
Tim Scott ◽  
Erin King ◽  
...  
Keyword(s):  
Extreme Events ◽  
High Energy ◽  
Water Levels ◽  
Energy Conditions ◽  
Coastal Change ◽  
Extreme Waves ◽  
Starting Point ◽  
Wide Range ◽  
Order Of Magnitude ◽  
A Site

Headland bypassing is the transport of sediment around rocky headlands by wave and tidal action, associated with high-energy conditions and embayment circulation (e.g., mega-rips). Bypassing may be a key component in the sediment budget of many coastal cells, the quantification of which is required to predict the coastal response to extreme events and future coastal change. Waves, currents, and water levels were measured off the headland of a sandy, exposed, and macrotidal beach in 18-m and 26-m depths for 2 months. The observations were used to validate a Delft3D morphodynamic model, which was subsequently run for a wide range of scenarios. Three modes of bypassing were determined: (i) tidally-dominated control during low–moderate wave conditions [flux O (0–102 m3 day−1)]; (ii) combined tidal- and embayment circulation controls during moderate–high waves [O (103 m3 day−1)]; and (iii) multi-embayment circulation control during extreme waves [O (104 m3 day−1)]. A site-specific bypass parameter is introduced, which accurately (R2 = 0.95) matches the modelled bypass rates. A 5-year hindcast predicts bypassing is an order of magnitude less than observed cross-shore fluxes during extreme events, suggesting that bypassing at this site is insignificant at annual timescales. This work serves a starting point to generalise the prediction of headland bypassing.

scholarly journals Antibacterial Effects of New Zealand Plant  Extracts against Mycobacteria

2021 ◽  
Author(s):  
◽  
Emma Anne Earl
Keyword(s):  
New Zealand ◽  
Current Knowledge ◽  
Antimycobacterial Activity ◽  
World Population ◽  
Bacteriostatic Activity ◽  
Native Plant ◽  
Important Species ◽  
Plant Samples ◽  
Starting Point ◽  
Drug Resistant Strains

<p>Mycobacterium tuberculosis, the causative agent of tuberculosis (TB) has infected approximately 1/3 of the world population, with 9.4 million new TB cases in 2008. In addition to increased cases of drug-resistant strains it is vital that novel antitubercular compounds are discovered in order to treat infections and reduce the time of current TB therapy courses. Natural resources such as plants are now being considered as the focus for discovering new compounds. Plants have long been investigated as a source of antibiotics for the treatment of human disease. New Zealand (NZ) contains a unique and diverse flora; however, to current knowledge no native plants have been examined for antimycobacterial activity. Using ethnobotany as a basis for selection, a total of 58 native plant samples were collected and tested for direct antimycobacterial activity. Samples were extracted with sterile distilled water (SDW), ethanol (EtOH) or methanol (MeOH) and screened for inhibition against the surrogate species, Mycobacterium smegmatis. Active plant samples were then validated for bacteriostatic activity towards M. bovis BCG and M. tuberculosis H37Ra as well as other clinically-important species. Nine extracts from the species Laurelia novae-zelandiae, Lophomyrtus bullata, Metrosideros excelsa, Myoporum laetum, Pittosporum tenuifolium, Pseudopanax crassifolius and Pseudowintera colorata were found to be active against M. smegmatis. Two active extracts were the bark and cambium extracts of Laurelia novae-zelandiae (Pukatea), which were reportedly used by indigenous Māori for the treatment of tubercular lesions. Upon further investigation these extracts also demonstrated bactericidal activity towards M. smegmatis as well as bacteriostatic activity towards the slow-growing species M. bovis BCG and M. tuberculosis. Purification techniques were then performed to improve the efficiency of activity and initial exploration of delivery systems was also examined. The bioactive extracts determined in this research offer a starting point for identifying their chemical basis of antimycobacterial activity with the objective of potentially discovering new anti-tubercular drugs.</p>

scholarly journals Antibacterial Effects of New Zealand Plant  Extracts against Mycobacteria

2021 ◽  
Author(s):  
◽  
Emma Anne Earl
Keyword(s):  
New Zealand ◽  
Current Knowledge ◽  
Antimycobacterial Activity ◽  
World Population ◽  
Bacteriostatic Activity ◽  
Native Plant ◽  
Important Species ◽  
Plant Samples ◽  
Starting Point ◽  
Drug Resistant Strains

<p>Mycobacterium tuberculosis, the causative agent of tuberculosis (TB) has infected approximately 1/3 of the world population, with 9.4 million new TB cases in 2008. In addition to increased cases of drug-resistant strains it is vital that novel antitubercular compounds are discovered in order to treat infections and reduce the time of current TB therapy courses. Natural resources such as plants are now being considered as the focus for discovering new compounds. Plants have long been investigated as a source of antibiotics for the treatment of human disease. New Zealand (NZ) contains a unique and diverse flora; however, to current knowledge no native plants have been examined for antimycobacterial activity. Using ethnobotany as a basis for selection, a total of 58 native plant samples were collected and tested for direct antimycobacterial activity. Samples were extracted with sterile distilled water (SDW), ethanol (EtOH) or methanol (MeOH) and screened for inhibition against the surrogate species, Mycobacterium smegmatis. Active plant samples were then validated for bacteriostatic activity towards M. bovis BCG and M. tuberculosis H37Ra as well as other clinically-important species. Nine extracts from the species Laurelia novae-zelandiae, Lophomyrtus bullata, Metrosideros excelsa, Myoporum laetum, Pittosporum tenuifolium, Pseudopanax crassifolius and Pseudowintera colorata were found to be active against M. smegmatis. Two active extracts were the bark and cambium extracts of Laurelia novae-zelandiae (Pukatea), which were reportedly used by indigenous Māori for the treatment of tubercular lesions. Upon further investigation these extracts also demonstrated bactericidal activity towards M. smegmatis as well as bacteriostatic activity towards the slow-growing species M. bovis BCG and M. tuberculosis. Purification techniques were then performed to improve the efficiency of activity and initial exploration of delivery systems was also examined. The bioactive extracts determined in this research offer a starting point for identifying their chemical basis of antimycobacterial activity with the objective of potentially discovering new anti-tubercular drugs.</p>

scholarly journals Searching for elusive dark sectors with terrestrial and celestial observations

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Roberto Contino ◽  
Kevin Max ◽  
Rashmish K. Mishra
Keyword(s):  
Field Theory ◽  
Broad Class ◽  
High Energy ◽  
Effective Field ◽  
Dark Sector ◽  
Minimum Requirement ◽  
Conformal Field ◽  
Starting Point ◽  
The Standard Model ◽  
Visible Sector

Abstract We consider the possible existence of a SM-neutral and light dark sector coupled to the visible sector through irrelevant portal interactions. Scenarios of this kind are motivated by dark matter and arise in various extensions of the Standard Model. We characterize the dark dynamics in terms of one ultraviolet scale Λuv, at which the exchange of heavy mediator fields generates the portal operators, and by one infrared scale ΛIR, setting the mass gap. At energies ΛIR « E « Λuv the dark sector behaves like a conformal field theory and its phenomenology can be studied model independently. We derive the constraints set on this scenario by high- and low-energy laboratory experiments and by astrophysical observations. Our results are conservative and serve as a minimum requirement that must be fulfilled by the broad class of models satisfying our assumptions, of which we give several examples. The experimental constraints are derived in a manner consistent with the validity of the effective field theory used to define the portal interactions. We find that high-energy colliders give the strongest bounds and exclude UV scales up to a few TeV, but only in specific ranges of the IR scale. The picture emerging from current searches can be taken as a starting point to design a future experimental strategy with broader sensitivity.

scholarly journals Multiwavelength Observations of Fast Radio Bursts

Universe ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 76
Author(s):  
Luciano Nicastro ◽  
Cristiano Guidorzi ◽  
Eliana Palazzi ◽  
Luca Zampieri ◽  
Massimo Turatto ◽  
...  
Keyword(s):  
Radio Burst ◽  
High Energy ◽  
Medium Size ◽  
Radio Bursts ◽  
Starting Point ◽  
Key Points ◽  
Fast Radio Burst ◽  
Theoretical Results ◽  
Observational Strategy ◽  
Shed Light

The origin and phenomenology of the Fast Radio Burst (FRB) remains unknown despite more than a decade of efforts. Though several models have been proposed to explain the observed data, none is able to explain alone the variety of events so far recorded. The leading models consider magnetars as potential FRB sources. The recent detection of FRBs from the galactic magnetar SGR J1935+2154 seems to support them. Still, emission duration and energetic budget challenge all these models. Like for other classes of objects initially detected in a single band, it appeared clear that any solution to the FRB enigma could only come from a coordinated observational and theoretical effort in an as wide as possible energy band. In particular, the detection and localisation of optical/NIR or/and high-energy counterparts seemed an unavoidable starting point that could shed light on the FRB physics. Multiwavelength (MWL) search campaigns were conducted for several FRBs, in particular for repeaters. Here we summarize the observational and theoretical results and the perspectives in view of the several new sources accurately localised that will likely be identified by various radio facilities worldwide. We conclude that more dedicated MWL campaigns sensitive to the millisecond–minute timescale transients are needed to address the various aspects involved in the identification of FRB counterparts. Dedicated instrumentation could be one of the key points in this respect. In the optical/NIR band, fast photometry looks to be the only viable strategy. Additionally, small/medium size radiotelescopes co-pointing higher energies telescopes look a very interesting and cheap complementary observational strategy.

scholarly journals Diverse floodplain deposits of reworked loess in a monsoon climate (Hanzhong Basin, central China)

2021 ◽  
pp. 1-17
Author(s):  
Jef Vandenberghe ◽  
Xun Yang ◽  
Xianyan Wang ◽  
Shejiang Wang ◽  
Huayu Lu
Keyword(s):  
Soil Formation ◽  
High Energy ◽  
Central China ◽  
Energy Conditions ◽  
Middle Pleistocene ◽  
Sedimentary Sequences ◽  
Varied Intensity ◽  
Floodplain Deposits ◽  
Flooding Events ◽  
Floodplain Sediments

Abstract This paper describes an assemblage of diverse floodplain facies of reworked loess (facies b, c) in a Middle Pleistocene monsoonal setting of the Hanzhong Basin, central China. The vertical and lateral sedimentary sequences show changing energy conditions. Apart from the highest energy in the channel facies (facies a), a relatively high energy floodplain environment (facies b) prevailed in waterlogged conditions, with small, laterally migrating (sub)channels. Facies b generally interfingers with aggrading horizontal sheets of overbank deposits in alluvial pools and swamps in a floodplain with much lower energy (facies c), in which phases of stability (soil formation) occasionally interrupted overbank deposition. Reworked loess forms the main part of the floodplain deposits. The paleosols are considered to have been formed under low hydrodynamic conditions in an interglacial environment. These interglacial conditions follow the commonly assumed glacial conditions of channel facies a. The sedimentary successions in the floodplain show a recurrent composition and cyclicity between wet and dry floodplain sedimentation terminated by stability with soil formation. The cyclic rhythm of stacked high- and low-energy floodplain sediments is attributed to varied intensity of different hydrodynamic flooding events that may have been due to changing monsoonal rainfall or simple intrinsic fluvial behavior.

Potential contribution of the wastewater sector to energy supply

2011 ◽  
Vol 63 (8) ◽  
pp. 1765-1771 ◽  
Author(s):  
S. Heubeck ◽  
R. M. de Vos ◽  
R. Craggs
Keyword(s):  
New Zealand ◽  
Potential Energy ◽  
Biological Treatment ◽  
High Energy ◽  
Technology Selection ◽  
Energy Yield ◽  
Potential Contribution ◽  
Energy Potential ◽  
Treatment Technologies ◽  
Future Potential

The biological treatment of wastewater could yield high energy fuels such as methane and alcohols, however most conventional treatment systems do not recover this energy potential. With a simple model of the energy yields of various wastewater treatment technologies it is possible to demonstrate how minor shifts in technology selection can lead the industry from being identified as predominantly energy intensive, to being recognised as a source of energy resources. The future potential energy yield is estimated by applying energy yield factors to alternative use scenarios of the same wastewater loads. The method for identifying the energy potential of wastewater was demonstrated for the New Zealand wastewater sector, but can equally be applied to other countries or regions. The model suggests that by using technologies that maximise the recovery of energy from wastewater, the potential energy yield from this sector would be substantially increased (six fold for New Zealand).

scholarly journals Involvement of Progranulin in Hypothalamic Glucose Sensing and Feeding Regulation

Endocrinology ◽  
2011 ◽  
Vol 152 (12) ◽  
pp. 4672-4682 ◽  
Author(s):  
Hyun-Kyong Kim ◽  
Mi-Seon Shin ◽  
Byung-Soo Youn ◽  
Churl Namkoong ◽  
So Young Gil ◽  
...  
Keyword(s):  
Neuropeptide Y ◽  
Energy Condition ◽  
Physiological Role ◽  
High Energy ◽  
Glucose Sensing ◽  
Energy Conditions ◽  
Related Peptide ◽  
Feeding Regulation ◽  
Nocturnal Feeding ◽  
Hypothalamic Regulation

Progranulin (PGRN) is a secreted glycoprotein with multiple biological functions, including modulation of wound healing and inflammation. Hypothalamic PGRN has been implicated in the development of sexual dimorphism. In the present study, a potential role for PGRN in the hypothalamic regulation of appetite and body weight was investigated. In adult rodents, PGRN was highly expressed in periventricular tanycytes and in hypothalamic neurons, which are known to contain glucose-sensing machinery. Hypothalamic PGRN expression levels were decreased under low-energy conditions (starvation and 2-deoxy-D-glucose administration) but increased under high-energy condition (postprandially). Intracerebrovetricular administration of PGRN significantly suppressed nocturnal feeding as well as hyperphagia induced by 2-deoxyglucose, neuropeptide Y, and Agouti-related peptide. Moreover, the inhibition of hypothalamic PGRN expression or action increased food intake and promoted weight gain, suggesting that endogenous PGRN functions as an appetite suppressor in the hypothalamus. Investigation of the mechanism of action revealed that PGRN diminished orexigenic neuropeptide Y and Agouti-related peptide production but stimulated anorexigenic proopiomelanocortin production, at least in part through the regulation of hypothalamic AMP-activated protein kinase. Notably, PGRN was also expressed in hypothalamic microglia. In diet-induced obese mice, microglial PGRN expression was increased, and the anorectic response to PGRN was blunted. These findings highlight a physiological role for PGRN in hypothalamic glucose-sensing and appetite regulation. Alterations in hypothalamic PGRN production or action may be linked to appetite dysregulation in obesity.

From Adatom Migration to Chemical Kinetics: Models for MBE, Mombe and MOCVD

1993 ◽  
Vol 312 ◽  
Author(s):  
D. D. Vvedensky ◽  
T. Shitarat ◽  
P. Smilauer ◽  
T. Kaneko ◽  
A. Zangwill
Keyword(s):  
Experimental Data ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
High Energy ◽  
Atomic Scale ◽  
Basic Model ◽  
Mobile Species ◽  
Local Environments ◽  
Starting Point

AbstractThe application of Monte Carlo simulations to various epitaxial growth methods is examined from the standpoint of incorporating only those kinetics processes that are required to explain experimental data. A basic model for molecular-beam epitaxy (MBE) is first introduced and some of the features that make it suitable for describing atomic-scale processes are pointed out. Extensions of this model for cases where the atomic constituents of the growing surface are delivered in the form of heteroatomic molecules are then considered. The experimental scenarios that is discussed is the homoepitaxy of GaAs(001) using metalorganic molecular-beam epitaxy (MOMBE) with triethylgallium (TEG) and precursors and using MOCVD with trimethylgallium (TMG). For MOMBE, the comparisons between simulations and experiments are based on reflection high-energy electron diffraction intensities, by analogy with comparisons made for MBE, while for metalorganic chemical vapor deposition (MOCVD) the simulations are compared to in situ glancingincidence x-ray scattering measurements. In both of these cases, the inclusion of a second mobile species to represent the precursor together with various rules for the decomposition of this molecule (in terms of rates and local environments) with be shown to provide a useful starting point for explaining the general trends in the experimental data and for further refinements of the model.

Stigma, decriminalisation, and violence against street-based sex workers: Changing the narrative

Sexualities ◽  
2018 ◽  
Vol 22 (7-8) ◽  
pp. 1288-1308 ◽  
Author(s):  
Lynzi Armstrong
Keyword(s):  
New Zealand ◽  
Sex Work ◽  
Sex Workers ◽  
Negative Impact ◽  
Worker Safety ◽  
Worker Rights ◽  
Sex Worker ◽  
Multiple Risks ◽  
Ongoing Work ◽  
Starting Point

It is well documented that sex workers manage risks in their work – such as the potential for violence and the multiple risks associated with stigma. While sex workers are commonly understood to be a stigmatised population, few studies have considered in depth how stigma operates in different legislative contexts, how it relates to sex-worker safety, and how it may be reduced. Stigma is understood to be exacerbated by the criminalisation of sex work, which defines sex workers as deviant others and consequently renders them more vulnerable to violence. However, as full decriminalisation of sex work is still relatively rare, there has been little in-depth exploration into the relationship between this legislative approach, risks of violence, and stigma. Drawing on the findings of in-depth interviews with street-based sex workers and sex-worker rights advocates, in this article I explore the links between stigma and violence, and discuss the challenges of reducing stigma associated with sex work in New Zealand, post-decriminalisation. I argue that while decriminalisation has undoubtedly benefited sex workers in New Zealand, stigma continues to have a negative impact – particularly for street-based sex workers. Decriminalisation should therefore be considered an essential starting point. However, ongoing work must focus on countering stigmatising narratives, to enable a safer society for all sex workers.

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