Formation of specialized propagules resistant to desiccation and cryopreservation in the threatened moss Ditrichum plumbicola (ditrichales, bryopsida)

Background and Aims Successful cryopreservation of bryophytes is linked to intrinsic desiccation tolerance and survival can be enhanced by pre-treatment with abscisic acid (ABA) and sucrose. The pioneer moss Ditrichum plumbicola is naturally subjected to desiccation in the field but showed unexpectedly low survival of cryopreservation, as well as a poor response to pre-treatment. The effects of the cryopreservation protocol on protonemata of D. plumbicola were investigated in order to explore possible relationships between the production in vitro of cryopreservation-tolerant asexual propagules and the reproductive biology of D. plumbicola in nature. Methods Protonemata were prepared for cryopreservation using a four-step protocol involving encapsulation in sodium alginate, pre-treatment for 2 weeks with ABA and sucrose, desiccation for 6 h and rapid freezing in liquid nitrogen. After each stage, protonemata were prepared for light and electron microscopy and growth on standard medium was monitored. Further samples were prepared for light and electron microscopy at intervals over a 24-h period following removal from liquid nitrogen and re-hydration. Key Results Pre-treatment with ABA and sucrose caused dramatic changes to the protonemata. Growth was arrested and propagules induced with pronounced morphological and cytological changes. Most cells died, but those that survived were characterized by thick, deeply pigmented walls, numerous small vacuoles and lipid droplets in their cytoplasm. Desiccation and cryopreservation elicited no dramatic cytological changes. Cells returned to their pre-dehydration and cryopreservation state within 2 h of re-hydration and/or removal from liquid nitrogen. Regeneration was normal once the ABA/sucrose stimulus was removed. Conclusions The ABA/sucrose pre-treatment induced the formation of highly desiccation- and cryopreservation-tolerant propagules from the protonemata of D. plumbicola. This parallels behaviour in the wild, where highly desiccation-tolerant rhizoids function as perennating organs allowing the moss to endure extreme environmental conditions. An involvement of endogenous ABA in the desiccation tolerance of D. plumbicola is suggested.

Considering research enquiry into biophilic urbanism and office worker productivity

In cities, people spend a significant portion of their time indoors, much of which is in office buildings. The quality and nature of these spaces have the potential to be a strong determinant of people’s health and wellbeing. There is a body of evidence that suggests experiences of nature increase the rate of attention recovery, reduce stress, depression and anxiety, and increase cognitive abilities. Further, the presence of nature inside buildings (such as pot plants and internal green walls) can improve indoor air quality, potentially reducing illness and increasing cognitive function. Urban design that integrates nature into the built environment to provide these benefits, among others, is called ‘biophilic urbanism’ and is the subject of growing international interest and research. The potential for these benefits to increase worker productivity in office buildings is of particular interest, as this could significantly increase the financial performance of office building-based organisations. However, productivity is a complex concept that is difficult to define, and affected by a multitude of factors, which make it difficult to measure. This inability to quantify productivity increases from investments in nature- experiences in office buildings is currently a significant barrier to such investments. Within this context, this paper considers opportunities for research to explore the relationship between office-based nature experiences and productivity, by reviewing existing research in this field and reflecting on the authors’ own experiences. This review has a particular focus on the importance of quantifying this link in order to encourage private property owners to voluntarily integrate nature into buildings to provide city-wide ecosystem service benefits. The paper begins with a contextual overview of how biophilic urbanism can potentially increase worker productivity. Existing methods of measuring and evaluating the performance of biophilic urbanism within the context of office buildings are then explored, along with a discussion of issues with such methods that are currently limiting investment in biophilic urbanism to increase worker productivity and wellbeing. This includes a summary of a survey within a Perth office building to explore the impact of views of nature through a window. Drawing on these insights, the paper makes recommendations regarding opportunities for focusing future investigations to enhance understanding of how biophilic urbanism can contribute to increased wellbeing and productivity in office buildings. This paper builds on work conducted as part of the Sustainable Built Environment National Research Centre Project 1.5, Harnessing the Potential of Biophilic Urbanism in Australia, which considered the role of nature integrated into the built environment in responding to emerging challenges of climate change, resource shortages and population pressures, while providing a host of co- benefits to a range of stakeholders.

Considering research enquiry into biophilic urbanism and office worker productivity

In cities, people spend a significant portion of their time indoors, much of which is in office buildings. The quality and nature of these spaces have the potential to be a strong determinant of people’s health and wellbeing. There is a body of evidence that suggests experiences of nature increase the rate of attention recovery, reduce stress, depression and anxiety, and increase cognitive abilities. Further, the presence of nature inside buildings (such as pot plants and internal green walls) can improve indoor air quality, potentially reducing illness and increasing cognitive function. Urban design that integrates nature into the built environment to provide these benefits, among others, is called ‘biophilic urbanism’ and is the subject of growing international interest and research. The potential for these benefits to increase worker productivity in office buildings is of particular interest, as this could significantly increase the financial performance of office building-based organisations. However, productivity is a complex concept that is difficult to define, and affected by a multitude of factors, which make it difficult to measure. This inability to quantify productivity increases from investments in nature- experiences in office buildings is currently a significant barrier to such investments. Within this context, this paper considers opportunities for research to explore the relationship between office-based nature experiences and productivity, by reviewing existing research in this field and reflecting on the authors’ own experiences. This review has a particular focus on the importance of quantifying this link in order to encourage private property owners to voluntarily integrate nature into buildings to provide city-wide ecosystem service benefits. The paper begins with a contextual overview of how biophilic urbanism can potentially increase worker productivity. Existing methods of measuring and evaluating the performance of biophilic urbanism within the context of office buildings are then explored, along with a discussion of issues with such methods that are currently limiting investment in biophilic urbanism to increase worker productivity and wellbeing. This includes a summary of a survey within a Perth office building to explore the impact of views of nature through a window. Drawing on these insights, the paper makes recommendations regarding opportunities for focusing future investigations to enhance understanding of how biophilic urbanism can contribute to increased wellbeing and productivity in office buildings. This paper builds on work conducted as part of the Sustainable Built Environment National Research Centre Project 1.5, Harnessing the Potential of Biophilic Urbanism in Australia, which considered the role of nature integrated into the built environment in responding to emerging challenges of climate change, resource shortages and population pressures, while providing a host of co- benefits to a range of stakeholders.

Spontaneous large volume adipose tissue generation from a vascularized pedicled fat flap inside a chamber space

A novel method of spontaneous generation of new adipose tissue from an existing fat flap is described. A defined volume of fat flap based on the superficial inferior epigastric vascular pedicle in the rat was elevated and inset into a hollow plastic chamber implanted subcutaneously in the groin of the rat. The chamber walls were either perforated or solid and the chambers either contained poly(D,L-lactic-co-glycolic acid) (PLGA) sponge matrix or not. The contents were analyzed after being in situ for 6 weeks. The total volume of the flap tissue in all groups except the control groups, where the flap was not inserted into the chambers, increased significantly, especially in the perforated chambers (0.08 ± 0.007 mL baseline compared to 1.2 ± 0.08 mL in the intact ones). Volume analysis of individual component tissues within the flaps revealed that the adipocyte volume increased and was at a maximum in the chambers without PLGA, where it expanded from 0.04 ± 0.003 mL at insertion to 0.5 ± 0.08 mL (1250% increase) in the perforated chambers and to 0.16 ± 0.03 mL (400% increase) in the intact chambers. Addition of PLGA scaffolds resulted in less fat growth. Histomorphometric analysis rather than simple hypertrophy documented an increased number of adipocytes. The new tissue was highly vascularized and no fat necrosis or atypical changes were observed.

The experience of learning in “The Cube” : Queensland University of Technology’s giant interactive multimedia environment

In this paper we report findings of the first phase of an investigation, which explored the experience of learning amongst high-level managers, project leaders and visitors in QUT’s “Cube”. “The Cube” is a giant, interactive, multi-media display; an award-winning configuration that hosts several interactive projects. The research team worked with three groups of participants to understand the relationship between a) the learning experiences that were intended in the establishment phase; b) the learning experiences that were enacted through the design and implementation of specific projects; and c) the lived experiences of learning of visitors interacting with the system. We adopted phenomenography as a research approach, to understand variation in people’s understandings and lived experiences of learning in this environment. The project was conducted within the first twelve months of The Cube being open to visitors.

Key facilitators and barriers to quality of life in residential aged care : the role of design

Australia is undergoing a critical demographic transition: the population is ageing. By 2050, one in four Australians will be older than 65 years and by 2031, the number of older Australians requiring residential aged care will increase 63%, to 1.4 million (ABS, 2005). In anticipation of this global demographic transition, the World Health Organisation has advocated ‘active ageing’, identifying health, participation and security as the three key factors that enhance quality of life for people as they age (WHO, 2002). While there is considerable discussion and acceptance of active ageing principles, little is known about the experience of ‘active ageing’ for older Australians who live in Residential Aged Care Facilities (RACF). This research addresses this knowledge gap by exploring the key facilitators and barriers to quality of life and active ageing in aged care from the perspective of aged care residents (n=12). To do this, the project documented the initial expectations and daily life experience of new residents living in a RACF over a one-year period. Combined with in-depth interviews and surveys, the project utilised Photovoice methodology - where participants used photography to record their lived experiences. The initial findings suggest satisfaction with living in aged care centers around five key themes; resident’s mental attitude to living in aged care, forming positive peer and staff relationships, self-determination and maintaining independence, opportunities to participate in interesting activities, and living in a safe and comfortable physical environment. This paper reports on the last of these five key themes, focusing on the role of design in facilitating quality of life, specifically: “living within these walls��� – safety, comfort and the physical environment.

Energy efficiency in nanoscale synthesis using nanosecond plasmas

We report a nanoscale synthesis technique using nanosecond-duration plasma discharges. Voltage pulses 12.5 kV in amplitude and 40 ns in duration were applied repetitively at 30 kHz across molybdenum electrodes in open ambient air, generating a nanosecond spark discharge that synthesized well-defined MoO 3 nanoscale architectures (i.e. flakes, dots, walls, porous networks) upon polyamide and copper substrates. No nitrides were formed. The energy cost was as low as 75 eV per atom incorporated into a nanostructure, suggesting a dramatic reduction compared to other techniques using atmospheric pressure plasmas. These findings show that highly efficient synthesis at atmospheric pressure without catalysts or external substrate heating can be achieved in a simple fashion using nanosecond discharges.

Fire performance and design of load bearing light gauge steel frame wall systems exposed to realistic design fires

This paper presents the fire performance results of light gauge steel frame (LSF) walls lined with single and double plasterboards, and externally insulated with rock fibre insulation as obtained using a finite element analysis based parametric study. A validated numerical model was used to study the influence of various fire curves developed for a range of compartment characteristics. Data from the parametric study was utilized to develop a simplified method to predict the fire resistance ratings of LSF walls exposed to realistic design fire curves. Further, this paper also presents the details of suitable fire design rules based on current cold-formed steel standards and the modifications proposed by previous researchers. Of these the recently developed design rules by Gunalan and Mahendran [1] were investigated to determine their applicability to predict the axial compression strengths and fire resistance ratings (FRR) of LSF walls exposed to realistic design fires. Finally, the stud failure times obtained from fire design rules and finite element studies were compared for LSF walls lined with single and double plasterboards, and externally insulated with rock fibres under realistic design fire curves.

Diagnostics and two-dimensional simulation of low-frequency inductively coupled plasmas with neutral gas heating and electron heat fluxes

This article presents the results on the diagnostics and numerical modeling of low-frequency (∼460 KHz) inductively coupled plasmas generated in a cylindrical metal chamber by an external flat spiral coil. Experimental data on the electron number densities and temperatures, electron energy distribution functions, and optical emission intensities of the abundant plasma species in low/intermediate pressure argon discharges are included. The spatial profiles of the plasma density, electron temperature, and excited argon species are computed, for different rf powers and working gas pressures, using the two-dimensional fluid approach. The model allows one to achieve a reasonable agreement between the computed and experimental data. The effect of the neutral gas temperature on the plasma parameters is also investigated. It is shown that neutral gas heating (at rf powers≥0.55kW) is one of the key factors that control the electron number density and temperature. The dependence of the average rf power loss, per electron-ion pair created, on the working gas pressure shows that the electron heat flux to the walls appears to be a critical factor in the total power loss in the discharge.

Tailoring of ion species composition in complex plasmas with charge exchange collisions

A generic approach towards tailoring of ion species composition in reactive plasmas used for nanofabrication of various functional nanofilms and nanoassemblies, based on a simplified model of a parallel-plate rf discharge, is proposed. The model includes an idealized reactive plasma containing two neutral and two ionic species interacting via charge exchange collisions in the presence of a microdispersed solid component. It is shown that the number densities of the desired ionic species can be efficiently managed by adjusting the dilution of the working gas in a buffer gas, rates of electron impact ionization, losses of plasma species on the discharge walls, and surfaces of fine particles, charge exchange rates, and efficiency of three-body recombination processes in the plasma bulk. The results are relevant to the plasma-aided nanomanufacturing of ordered patterns of carbon nanotip and nanopyramid microemitters.

Modelling electronegative complex plasma systems

The control of the generation and assembly of the electronegative plasma-grown particles is discussed. Due to the large number of elementary processes of particle creation and loss, electronegative complex plasmas should be treated as open systems where the stationary states are sustained by various particle creation and loss processes in the plasma bulk, on the walls, and on the dust grain surfaces. To be physically self-consistent, ionization, diffusion, electron attachment, recombination, dust charge variation, and dissipation due to electron and ion elastic collisions with neutrals and fine particles, as well as charging collisions with the dust, must be accounted for.

Ion-acoustic waves in a complex plasma with negative ions

Negative ions and negatively charged micro- to nano-meter sized dust grains are ubiquitous in astrophysical as well as industrial processing plasmas. The negative ions can appear in electro-negative plasmas as a result of elementary processes such as dissociative or non-dissociative electron attachment to neutrals. They are usually rather small in number, and in general do not affect the overall plasma behavior. On the other hand, since the dust grains are almost always highly negative, even in small numbers they can take up a considerable proportion of the total negative charge in the system. The presence of dusts can affect the characteristics of most collective processes of the plasma since the charge balance in both the steady and dynamic states can be significantly altered. Another situation that often occurs is that the electron number density becomes small because of their absorption by the dust grains or the discharge walls. In this case the negative ions in the plasma can play a very important role. Here, a self-consistent theory of linear waves in complex laboratory plasmas containing dust grains and negative ions is presented. A comprehensive model for such plasmas including source and sink effects associated with the presence of dust grains and negative ions is introduced. The stationary state of the plasma as well as the dispersion and damping characteristics of the waves are investigated. All relevant processes, such as ionization, diffusion, electron attachment, negative-positive ion recombination, dust charge relaxation, and dissipation due to electron and ion elastic collisions with neutrals and dust particles, as well as charging collisions with the dusts, are taken into consideration.

A meshfree particle based model for microscale shrinkage mechanisms of food materials in drying conditions

Cells are the fundamental building block of plant based food materials and many of the food processing born structural changes can fundamentally be derived as a function of the deformations of the cellular structure. In food dehydration the bulk level changes in porosity, density and shrinkage can be better explained using cellular level deformations initiated by the moisture removal from the cellular fluid. A novel approach is used in this research to model the cell fluid with Smoothed Particle Hydrodynamics (SPH) and cell walls with Discrete Element Methods (DEM), that are fundamentally known to be robust in treating complex fluid and solid mechanics. High Performance Computing (HPC) is used for the computations due to its computing advantages. Comparing with the deficiencies of the state of the art drying models, the current model is found to be robust in replicating drying mechanics of plant based food materials in microscale.

Experimental investigation of post-fire mechanical properties of cold-formed steels

Cold-formed steel members are widely used in residential, industrial and commercial buildings as primary load-bearing elements. During fire events, they will be exposed to elevated temperatures. If the general appearance of the structure is satisfactory after a fire event then the question that has to be answered is how the load bearing capacity of cold-formed steel members in these buildings has been affected. Hence after such fire events there is a need to evaluate the residual strength of these members. However, the post-fire behaviour of cold-formed steel members has not been investigated in the past. This means conservative decisions are likely to be made in relation to fire exposed cold-formed steel buildings. Therefore an experimental study was undertaken to investigate the post-fire mechanical properties of cold-formed steels. Tensile coupons taken from cold-formed steel sheets of three different steel grades and thicknesses were exposed to different elevated temperatures up to 800 oC, and were then allowed to cool down to ambient temperature before they were tested to failure. Tensile coupon tests were conducted to obtain their post-fire stress-strain curves and associated mechanical properties (yield stress, Young’s modulus, ultimate strength and ductility). It was found that the post-fire mechanical properties of cold-formed steels are reduced below the original ambient temperature mechanical properties if they had been exposed to temperatures exceeding 300 oC. Hence a new set of equations is proposed to predict the post-fire mechanical properties of cold-formed steels. Such post-fire mechanical property assessments allow structural and fire engineers to make an accurate prediction of the safety of fire exposed cold-formed steel buildings. This paper presents the details of this experimental study and the results of post-fire mechanical properties of cold-formed steels. It also includes the results of a post-fire evaluation of cold-formed steel walls.

Domestic ecologies : gender and domesticity in Harold Pinter's Rooms

Harold Pinter's work opens the walls to the relatively closed rooms of domesticity. The room of the love affair, the unpredictable liaison, the cramped cluttered rooms of poverty and the disaffected. This study uses Pinter's rooms to analyse existing ideologies of gender, territory, power and domesticity. Pinter's rooms are more often than not reflections of familiar domestic spaces. This research investigates Pinter's rooms through a case study of a theatre set for one of his plays and textual analysis of selected works, developing an understanding of how Pinter's characters reflect behaviours within the domestic environment, mimicking while subverting domestic ecologies.