121 research outputs found
Southern extensions for Holocene records of Australian pelican (Pelecanus conspicillatus) and New Zealand musk duck (Biziura delautouri) in New Zealand
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Substance deposition assessment in obstructed pulmonary system through numerical characterization of airflow and inhaled particles attributes
Background Chronic obstructive pulmonary disease (COPD) and asthma are considered as the two most widespread obstructive lung diseases, whereas they affect more than 500 million people worldwide. Unfortunately, the requirement for detailed geometric models of the lungs in combination with the increased computational resources needed for the simulation of the breathing did not allow great progress to be made in the past for the better understanding of inflammatory diseases of the airways through detailed modelling approaches. In this context, computational fluid dynamics (CFD) simulations accompanied by fluid particle tracing (FPT) analysis of the inhaled ambient particles are deemed critical for lung function assessment. Also they enable the understanding of particle depositions on the airways of patients, since these accumulations may affect or lead to inflammations. In this direction, the current study conducts an initial investigation for the better comprehension of particle deposition within the lungs. More specifically, accurate models of the airways obstructions that relate to pulmonary disease are developed and a thorough assessment of the airflow behavior together with identification of the effects of inhaled particle properties, such as size and density, is conducted. Our approach presents a first step towards an effective personalization of pulmonary treatment in regards to the geometric characteristics of the lungs and the in depth understanding of airflows within the airways. Methods A geometry processing technique involving contraction algorithms is established and used to employ the different respiratory arrangements associated with lung related diseases that exhibit airways obstructions. Apart from the normal lung case, two categories of obstructed cases are examined, i.e. models with obstructions in both lungs and models with narrowings in the right lung only. Precise assumptions regarding airflow and deposition fraction (DF) over various sections of the lungs are drawn by simulating these distinct incidents through the finite volume method (FVM) and particularly the CFD and FPT algorithms. Moreover, a detailed parametric analysis clarifies the effects of the particles size and density in terms of regional deposition upon several parts of the pulmonary system. In this manner, the deposition pattern of various substances can be assessed. Results For the specific case of the unobstructed lung model most particles are detected on the right lung (48.56% of total, when the air flowrate is 12.6 L/min), a fact that is also true when obstructions arise symmetrically in both lungs (51.45% of total, when the air flowrate is 6.06 L/min and obstructions occur after the second generation). In contrast, when narrowings are developed on the right lung only, most particles are pushed on the left section (68.22% of total, when the air flowrate is 11.2 L/min) indicating that inhaled medication is generally deposited away from the areas of inflammation. This observation is useful when designing medical treatment of lung diseases. Furthermore, particles with diameters from 1 μm to 10 μm are shown to be mainly deposited on the lower airways, whereas particles with diameters of 20 μm and 30 μm are mostly accumulated in the upper airways. As a result, the current analysis indicates increased DF levels in the upper airways when the particle diameter is enlarged. Additionally, when the particles density increases from 1000 Kg/m3 to 2000 Kg/m3, the DF is enhanced on every generation and for all cases investigated herein. The results obtained by our simulations provide an accurate and quantitative estimation of all important parameters involved in lung modeling. Conclusions The treatment of respiratory diseases with inhaled medical substances can be advanced by the clinical use of accurate CFD and FPT simulations and specifically by evaluating the deposition of inhaled particles in a regional oriented perspective in regards to different particle sizes and particle densities. Since a drug with specific characteristics (i.e. particle size and density) exhibits maximum deposition on particular lung areas, the current study provides initial indications to a qualified physician for proper selection of medication
From Ideal to Practice and Back Again: Beginning Teachers Teaching for Social Justice
The five authors of this article designed a multicase study to follow recent graduates of an elementary preservice teacher education program into their beginning teaching placements and explore the ways in which they enacted social justice curricula. The authors highlight the stories of three beginning teachers, honoring the plurality of their conceptions of social justice teaching and the resiliency they exhibited in translating social justice ideals into viable pedagogy. They also discuss the struggles the teachers faced when enacting social justice curricula and the tenuous connection they perceived between their conceptions and their practices. The authors emphasize that such struggles are inevitable and end the article with recommendations for ways in which teacher educators can prepare beginning teachers for the uncertain journey of teaching for social justice
Expectations for population growth at new breeding locations for the vulnerable New Zealand sea lion (Phocarctos hookeri) using a simulation model
Copyright © 2003 Elsevier Ltd. All rights reserved.Management plans for threatened or recovering large vertebrate species that are increasing in population size and range focus on the establishment of viable populations within set temporal limits. New Zealand (Hookers) sea lions (Phocarctos hookeri) were declared a threatened species in 1997, and New Zealand legislation requires that threatened species of marine mammals must be managed to reduce human-induced mortality and achieve a non-threatened status within 20 years. The present breeding distribution of P. hookeri is highly localised, with over 95% of total annual pup production located at Auckland Islands and almost all of the remainder at Campbell Island. Breeding elsewhere has been ephemeral or restricted to <10 adult females. The only recorded sustainable breeding at a new location has been at Otago, South Island, New Zealand. This breeding population consisted of a total of four breeding females in 2002 and is derived from one immigrant female that gave birth to her first pup in the 1993/1994 breeding season. The New Zealand Department of Conservation management plan specifies that to achieve a non-threatened status P. hookeri (1) at Otago must increase in the number of breeding females to greater-or-equal, slanted10, and (2) must establish greater-or-equal, slantedtwo new breeding locations within the 20-year time frame, each with greater-or-equal, slanted10 breeding females. This study 1) projects the population growth trends at a new location (Otago) to see if it will achieve greater-or-equal, slanted10 breeding females within the legislated time frame, and (2) examines the likelihood that other breeding locations will establish elsewhere given the demographic information available for this species. We present 20 deterministic and three stochastic Leslie matrix model scenarios for female population growth for the initial years following the start of breeding at a new location. Our results indicate that (1) a new breeding population derived from one immigrant female is unlikely to reach 10 breeding females in 20 years; this duration is more likely to be 23–41 years (deterministic models) or 23–26 years (stochastic model), (2) the likelihood of two new sites establishing within 20 years is unquantifiable, but the probability is low, and (3) if the legislated outcome and time limit are not revised in the population management plan, the feasibility and effectiveness of re-locating young females could be investigated.http://www.elsevier.com/wps/find/journaldescription.cws_home/405853/description#descriptio
Distribution and biomass of two squid species off southern New Zealand: Nototodarus sloanii and Moroteuthis ingens
The distribution and biomass of two species of squid, the ommastrephid arrow squid Nototodarus sloanii and the onychoteuthid squid Moroteuthis ingens, were analysed off southern New Zealand. These two species are the most important and abundant species in this region of the South Pacific Ocean. Data were obtained from extensive NIWA research cruises over 10 years. There was a sharp demarcation between the distribution of the two species, with N. sloanii occurring predominantly shallower than 600 m, with the greatest biomass less than 300 m. In contrast, M. ingens had the highest biomass between 650 and 700 m and occurred down to 1400 m. The biomass of N. sloanii reached more than 3500 kg · km-2, with an average catch rate of over 186 kg · km-2. In contrast, the biomass of M. ingens was more than an order of magnitude less, with all catch weights less than 200 kg · km-2 and an average catch rate less than 17 kg · km-2. The separation of these two species appeared to be related to depth, temperature and, possibly, salinity. N. sloanii occurred predominantly in warmer, shallower subtropical waters while M. ingens occurred in deeper, cooler subantarctic and antarctic intermediate water masses. The Subtropical Front formed a major barrier between the distribution of these two squid species
An experimental study of nightime air-pollutant transport over complex terrain in Athens
The Design and Use of a Nest Box for Yellow-eyed Penguins Megadyptes Antipodes: a Response to a Conservation Need
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