bluuebunny/crossref_metadata_2025 huggingface dataset:
Electroluminescence from carbon nanotube films resistively heated in air
Authors: Janas Dawid , Czechowski Nikodem , Krajnik Bartosz , Mackowski Sebastian , Koziol Krzysztof K.
Published: May 2013

Light emission from carbon nanotube (CNT) films was explored in both the near-infrared and the infrared spectral regions upon application of external bias voltage. We obviated the need to use sophisticated vacuum apparatus by employing state-of-the-art optics and detection system. It enabled us to sensitively probe electroluminescence at relatively low temperatures (T ∼ 300 °C) in ambient conditions and investigate the character of emission from CNT assemblies in real life conditions. The observed spectral response revealed distinct features and the results strongly suggest that CNT assemblies are promising candidates for optoelectronic applications, particularly in the field of telecommunication.
Femtosecond laser plasma plume characteristics in the nanojoule ablation regime
Authors: Banerjee S. P. , Chen Zhijiang , Fedosejevs R.
Published: May 2013

Laser ablation of chromium with nanojoule energy UV femtosecond pulses under background pressure conditions between 0.3 Torr and 700 Torr is studied and the corresponding plasma plume images at different times after irradiation are measured. The ablation focal spot is less than or the order of a micron when 170 nJ of laser pulse energy is used. This low pulse energy leads to short lifetimes of the plasma of the order of tens of nanoseconds. The plume shape changes with ambient pressure due to the collision with background gas. An axially stretched plume changes to a more circular plume as the pressure increases. In addition, a separation of the ionic and atomic components is observed at lower pressure. These two components move at significantly different velocities as well. The plasma plume expands at almost constant velocity at very low pressure but exhibits significant deceleration at higher pressure reaching an asymptotic stopping distance. Plume images are also obtained near the ablation threshold pulse energy. The plume characteristics are compared to different models of plume expansion.
Engineering polarization rotation in ferroelectric bismuth titanate
Authors: Roy Amritendu , Prasad Rajendra , Auluck Sushil , Garg Ashish
Published: May 2013

We report a combined experimental-theoretical study showing that collective application of rare earth doping on Bi-site of ferroelectric bismuth titanate (Bi4Ti3O12) and epitaxial strain leads to only a small increase in c-axis polarization, resolving conflicts of previous experimental data on c-axis oriented thin films. However, as shown by our first principles calculations, a modest c-axis polarization can be induced by simultaneous Bi(A) and Ti(B) site doping in bismuth titanate. This approach, correlating doping, epitaxial strain, and polarization in ferroic oxides, could be useful to tailor oxide compositions, assisting in the growth of epitaxial films along easy growth directions yielding reasonable polarization.
Scaling-induced enhancement of X-ray luminescence in CsI(Na) crystals
Authors: Liu Fang , Ouyang Xiaoping , Tang Minghua , Xiao Yongguang , Liu Bin , Zhang Xuebin , Feng Yi , Zhang Jinping , Liu Jinliang
Published: May 2013

We report on the diameter dependence luminescence property of CsI(Na) crystals under X-ray excitation. When CsI(Na) crystal diameter decreases to nano-scale, the X-ray excited luminescence decay time is speeding up from ∼600 ns to ∼10 ns and 420 nm Na-related cathodeluminescence is affected drastically. The reason is confirmed that diameter reduction leads surface effect to accelerate the excitons' quenching. These measurement results identify a critical distinguished boundary ∼20 μm) of crystal diameter, which provide a new way to potential application of CsI(Na) crystals in the development of fast X-ray and gamma scintillator film detectors with large area.
Effects of two-step Mg doping in p-GaN on efficiency characteristics of InGaN blue light-emitting diodes without AlGaN electron-blocking layers
Authors: Ryu Han-Youl , Lee Jong-Moo
Published: May 2013

A light-emitting diode (LED) structure containing p-type GaN layers with two-step Mg doping profiles is proposed to achieve high-efficiency performance in InGaN-based blue LEDs without any AlGaN electron-blocking-layer structures. Photoluminescence and electroluminescence (EL) measurement results show that, as the hole concentration in the p-GaN interlayer between active region and the p-GaN layer increases, defect-related nonradiative recombination increases, while the electron current leakage decreases. Under a certain hole-concentration condition in the p-GaN interlayer, the electron leakage and active region degradation are optimized so that high EL efficiency can be achieved. The measured efficiency characteristics are analyzed and interpreted using numerical simulations.
Pressure-dependent electrical conductivity of freestanding three-dimensional carbon nanotube network
Authors: Camilli Luca , Pisani Claudia , Passacantando Maurizio , Grossi Valentina , Scarselli Manuela , Castrucci Paola , De Crescenzi Maurizio
Published: May 2013

The dependence of electrical conductivity on compression of a freestanding three-dimensional carbon nanotube (CNT) network is investigated. This macrostructure is made of mm-long and entangled CNTs, forming a random skeleton with open pores. The conductivity linearly increases with the applied compression. This behaviour is due to increase of percolating pathways—contacts among neighbouring CNTs—under loads that is highlighted by in situ scanning electron microscopy analysis. The network sustains compressions up to 75% and elastically recovers its morphology and conductivity during the release period. The repeatability coupled with the high mechanical properties makes the CNT network interesting for pressure-sensing applications.
Stress-modulated exciton polariton Josephson effect in a semiconductor microcavity
Authors: Zhang Chuanyi , Jin Guojun
Published: May 2013

We demonstrate that the exciton polariton Josephson effect can be effectively modulated by a uniaxial stress in a semiconductor microcavity. By increasing the stress, we can show there are two critical transition stresses, which correspond to the 0-π and dc-ac transition, respectively. We find that the ac Josephson frequency increases with the stress and the macroscopic quantum self-trapping can appear by regulating the stress. We also find that the Shapiro steps emerge under appropriate conditions, but some steps are suppressed. In contrast to a conventional superconducting tunnel junction, it is exposed that all the rich phenomena come from the competition between the interaction of exciton polaritons and the energy difference induced by the stress. It is feasible that these results can be experimentally verified.
First-principles study of native point defects in Bi2Se3
Authors: Xue L. , Zhou P. , Zhang C. X. , He C. Y. , Hao G. L. , Sun L. Z. , Zhong J. X.
Published: May 2013

Using first-principles method within the framework of the density functional theory, we study the influence of native point defect on the structural and electronic properties of Bi2Se3. Se vacancy in Bi2Se3 is a double donor, and Bi vacancy is a triple acceptor. Se antisite (SeBi) is always an active donor in the system because its donor level (ɛ(+1/0)) enters into the conduction band. Interestingly, Bi antisite (BiSe1) in Bi2Se3 is an amphoteric dopant, acting as a donor when μe < 0.119 eV (the material is typical p-type) and as an acceptor when μe > 0.251 eV (the material is typical n-type). The formation energies under different growth environments (such as Bi-rich or Se-rich) indicate that under Se-rich condition, SeBi is the most stable native defect independent of electron chemical potential μe. Under Bi-rich condition, Se vacancy is the most stable native defect except for under the growth window as μe > 0.262 eV (the material is typical n-type) and ΔμSe < −0.459 eV (Bi-rich), under such growth window BiSe1 carrying one negative charge is the most stable one.
Development of an accreditation program for Point of Care Testing (PoCT) in general practice
Authors: Tirimacco Rosy , Glastonbury Briony , Laurence Caroline O. , Bubner Tanya K. , Shephard Mark D. , Beilby Justin J.
Published: May 2013

Objectives.
To describe the development and evaluation of an accreditation program for Point of Care Testing (PoCT) in general practice, which was part of the PoCT in general practice (GP) Trial conducted in 2005–07 and funded by the Australian Government.

Setting and participants.
Thirty general practices based in urban, rural and remote locations across South Australia, New South Wales and Victoria, which were in the intervention arm of the PoCT Trial were part of the accreditation program. A PoCT accreditation working party was established to develop an appropriate accreditation program for PoCT in GP. A multidisciplinary accreditation team was formed consisting of a medical scientist, a general practitioner or practice manager, and a trial team representative.

Methodology and sequence of events.
To enable practices to prepare for accreditation a checklist was developed describing details of the accreditation visit. A guide for surveyors was also developed to assist with accreditation visits. Descriptive analysis of the results of the accreditation process was undertaken.

Outcomes.
Evaluation of the accreditation model found that both the surveyors and practice staff found the process straightforward and clear. All practices (i.e. 100%) achieved second-round accreditation.

Discussion and lessons learned.
The accreditation process highlighted the importance of ongoing education and support for practices performing PoCT.

What is known about the topic?
Currently there is no rebate for Point of Care testing in Australia. Before the Australian Government can consider a rebate it has to be shown that PoCT is safe for patient care. Implementation of a quality framework and an accreditation model for PoCT is vital to ensure that clinical care is not compromised by use of this technology.

What does this paper add?
This paper provides a model for PoCT accreditation that meets requirements of both the GP and scientific community. It reports on the first government-funded PoCT in general practice trial and illustrates what needs to be considered if the Government decides to fund PoCT in general practice.

What are the implications for practitioners?
Description of a PoCT accreditation process highlights to practitioners what is entailed in following the interim standards for PoCT currently available. This study is an important piece of work as it shows that PoCT in general practice can be performed safely within a quality framework that meets scientific accreditation requirements.
The active management of surgical waiting lists: a urological surgery case study
Authors: Briggs Russell J. , Smith Katrina M. , Dejager Ebony M. , Callahan John T. , Abernethy Jennifer A. , Dunn Eddie J. , Hunter-Smith David J.
Published: May 2013

Elective surgery waiting list management is a major public healthcare issue. This case study describes an integrated multifaceted approach to waiting list management at Peninsula Health, a public health service in Victoria, Australia. At the commencement of this study it was recognised that several issues associated with the urological surgical service constituted potential clinical risk. These included: recall mechanisms for multiple surveillance procedures; significant resource deficits; and long surgery waiting times. Responding to these issues a multifaceted approach to wait list management was implemented including: audit; direct lines of communication between clinical and administrative staff; urgent caseload management; utilisation of the Elective Surgery Access Scheme; financial and resource analysis justifying the appointment of a full-time urologist, and the establishment of a urology service from a satellite campus; implementation of a recall database; development of an outpatient service; and commencement of a day surgery initiative. This approach yielded results that included a 67% reduction in the number of ‘ready for care’ patients and a 78% reduction in the number of patients classified as ‘overdue for surgery’. Average wait time for semi-urgent and non-urgent patients reduced from 248 days to 180 days in the 10-month period. What is known about the topic? Currently there are ~3000 people on the elective surgery waiting list in Victoria. Reasons for delays are multifactorial including shortage of beds, lack of surgeons, theatres and equipment. Patients are placed on the surgery waiting list according to a clinical urgency category assigned by their specialist. These categories are used by the hospitals to ensure that the patients with the greatest need are treated in the shortest period of time. Despite this, the numbers on the elective waiting lists within certain surgical specialities continue to grow and the numbers seen within the recommended time decreases. What does this paper add? This paper outlines a management strategy for the urology wait list at a large Victorian hospital. It outlines six approaches, the implementation of which had a measurable positive effect on the waiting list numbers. What are the implications for practitioners? The strategies put into place have been sustainable and continue to ensure that the urology waiting list is well managed.
Social impact bonds and their application to preventive health
Authors: Fitzgerald John L.
Published: May 2013

Although preventive health in Australia has been acknowledged as central to national health and wellbeing, efforts to reform the delivery of preventive health have to date produced limited results. The financing of preventive health at a national level is based on outcome- or performance-based funding mechanisms; however, delivery of interventions and activities at a state level have not been subjected to outcome-based funding processes. A new financing tool being applied in the area of social services (social impact bonds) has emerged as a possible model for application in the prevention arena. This paper explores key issues in the consideration of this funding model in the prevention arena. When preventive health is conceptualised as a merit good, the role of government is clarified and outcome measures fully articulated, social impact bonds may be a viable funding option to supplement core public health activities.

What is known about the topic?
The complexities of outcome monitoring in preventive health are well understood. Likewise, the problem of linking funding to outcomes from preventive health practice has also been debated at length in health policy. However, not much is known about the application of social impact bonds into the preventive health arena.

What does this paper add?
This paper discusses the limitations and opportunities facing the application of the social impact bond financing model in the preventive health arena. This has not been undertaken previously.

What are the implications for practitioners?
Social impact bonds have received significant recent attention from federal and state government treasury departments as potential financing tools for government. Health policy practitioners are watching this space very closely to see the outcomes of a New South Wales trial. Health promotion practitioners and primary care practitioners who deliver preventive services will need to keep abreast of this issue as it will have significant impact on their practice if states and territories introduce outcome-based funding processes.
Diet of the Large-footed Myotis Myotis Mcropus at A Forest Stream Roost in Northern New South Wales
Authors: Law B , Urquhart CA
Published: May 2013

RECENT evidence indicates that the large-footed
myotis Myotis macropus (previously Myotis
adversus) is the sole representative of its genus in
Australia (Cooper et al. in press). These are small
bats that forage over pools of water in small streams,
rivers and lakes, using large feet to trawl for prey
along water surfaces (Dwyer 1970; Thompson and
Fenton 1982). Little is known about their diet. Fish
have been confirmed in the diet of M. macropus at a
population that forages over a large lake, near
Brisbane (Robson 1984). Unidentified insect material
formed the bulk of the species? diet in Robson?s
study. A small number of scats were also examined
from M. macropus caught on the Murray River in
South Australia (Jansen 1987). These contained fish
remains and insects, particularly Chironominae
(midges) and Culicidae (mosquitoes). We studied the
diet of M. macropus at a forest stream to determine
the importance of aquatic prey and thus to help guide
management strategies for the species.
Should immunocontraception be used for wildlife population management?
Authors: Cooper DW
Published: May 2013

Immunocontraception involves eliciting an immune response against eggs, sperm or hormones
so that successful reproduction is prevented. Work in Australasia is aimed at European rabbits
(Oryctolagus cuniculus), red foxes (Vulpes vulpes), house mice (Mus musculus), common
brushtail possums (Trichosurus vulpecula), koalas (Phascolartcos cinereus) and kangaroos
(Macropus spp.), with the vaccines involved all containing self antigens or their relatives. Two
fundamental problems have been inadequately addressed in this research. The first problem is
that it is difficult to obtain strong immune responses against self antigens and so the vaccines
may be ineffective. Most published data on the effect of immunocontraceptives on reproduction
involve the use of an adjuvant of which there are many kinds. The materials enhance the
immune response greatly. The most frequently used is Freund?s adjuvant which can cause
chronic suffering. Its use on wildlife will lead to very negative public perceptions. There has
been no convincing demonstration that successful immunocontraception is possible with any
method of vaccination likely to be used in the field, if success is defined as contraception of a
proportion of the population high enough for management requirements. If it is assumed that
success can be achieved, the second fundamental problem arises with two potential
consequences. Even with adjuvant, a substantial minority of the vaccinated animals remains
fertile. The first consequence is that since failure to be contracepted is likely to be in part
genetic, there is likely to be rapid selection for these non-responders. The method will become
ineffective in a few generations. The second problem is that the offspring of the animals which
breed will have altered immune responses. Their capacities to respond to their own pathogens or
to harbor pathogens of other species in the same ecosystem are likely to be changed. The
presence of chlamydia in P. cinereus and bovine tuberculosis in New Zealand T. vulpecula
means that responses to these pathogens would have to be studied in offspring of
immunocontracepted parents to ensure that the offspring were not more susceptible to them.
New Zealand intentions to put an immunocontraceptive into a T. vulpecula gut worm must be
viewed with caution by Australia. The eggs of transgenic worms will be easily transplanted
either accidentally or deliberately back into Australia, and so infect T. vulpecula in Australia.
Diets of the re-introduced greater bilby (Macrotis lagotis) and burrowing bettong (Bettongia lesueur) in the Arid Recovery Reserve, Northern South Australia.
Authors: Bice J. , Moseby K.
Published: May 2013

The diets of re-introduced populations of the greater bilby (Macrotis lagotis) and burrowing bettong (Bettongia lesueur) were compared in arid South Australia. Scats were collected during five sampling periods over 15 months and dietary items were usually identified to species or genus level using macro and micro-histological techniques. Both species consumed a wide variety of food items but M. lagotis exhibited a greater use of invertebrate material and B. lesueur consumed more roots and perennial vegetation. Both species consumed a variety of seeds. There was high seasonal variation in the diets of both species and they appeared to be opportunistic dietary generalists, a condition beneficial for survival in the unpredictable arid zone climate. Although both species consumed items from the same broad dietary categories there was little dietary overlap of specific food items. Where overlap existed it was either temporally separated or comprised less than 19% of the total dietary volume suggesting a degree of resource partitioning between the two species. Whilst M. lagotis appears to have adapted to arid conditions by moving to follow ephemeral growth, B. lesueur is more sedentary and relies more on perennial vegetation. Within re-introduced confined populations where species movement is limited, M. lagotis may be more susceptible to population decline when conditions are dry, whereas B. lesueur may cause significant damage to perennial vegetation before experiencing population decline.
Patagonian huemul deer (Hippocamelus bisulcus) under captive conditions: an historical overview
Authors: Vidal Fernando , Smith-Flueck Jo Anne M. , Flueck Werner T. , Arias Eduardo
Published: May 2013

Huemul (Hippocamelus bisulcus) is a native deer of Patagonia whose endangered status has raised concerns for several decades, and yet conservation efforts to reverse this situation have not succeeded for most populations. Captive breeding projects attempted in the past were short-lived; animals were often lost due to poor methodology or unsanitary conditions during capture, transport stresses and rudimentary husbandry, and reintroductions could not be realised. Despite inappropriate capture and transport techniques of the past, a few individuals did make it to captive centres where they managed to survive for several years, with a minimum of eight births recorded. Regardless of the successes, it is the past failures that impinge upon today’s conservation efforts. In Argentina, a recent financially backed proposal – establishing a huemul breeding centre and including an in situ reintroduction program – was prevented by the prevailing opinion that captive breeding was neither feasible nor a necessary conservation tool for huemul. In Chile, the Huilo Huilo Foundation was able to obtain government consent and to establish the only captive breeding project in the last two decades with the main objective of reintroducing individuals in the future. Here we present some of the historical accounts to demonstrate the suitability of the species to captivity. We then describe the Chilean semi-captive breeding program (begun in 2005) including capture, transport, site selection, construction design and maintenance procedures of the two centres. The first centre has grown from an initial two adults to nine individuals. The second centre, which initially served for rehabilitation of an injured male, is awaiting arrival of some females. The success of the current program demonstrates that huemul can do well in captivity, and wherever considered beneficial, could serve as a significant conservation tool for the recovery of the species, inclusive of a research program and reintroductions to qualified sites.
Ewe nutrition in early and mid- to late pregnancy has few effects on fetal development
Authors: Martín N. P. , Kenyon P. R. , Morel P. C. H. , Pain S. J. , Jenkinson C. M. C. , Hutton P. G. , Morris S. T. , Peterson S. W. , Firth E. C. , Blair H. T.
Published: May 2013

Maternal nutrition affects fetal development, with potential lifelong consequences. The study reported here compared the anatomical development (dimensions and organs) of twin fetuses at Day 140 of gestation, from 58 twin-bearing ewes fed at one of three different nutritional treatments in early pregnancy [Day 21–50, Low (LD21–50) versus Medium (MD21–50) versus High (HD21–50)] and one of two different nutritional treatments in mid- to late pregnancy (Day 50–140, Medium (MD50–140) versus High (HD50–140)]. There were no effects (P > 0.05) of either early or mid- to late pregnancy nutrition on placental weight and fetal bodyweight or size measurements at Day 140. Semitendinosus muscles from LD21–50-HD50–140 fetuses were heavier (P < 0.05) than those from LD21–50-MD50–140 and HD21–50-HD50–140 fetuses, and fetuses from LD21–50 dams had lighter (P < 0.05) mammary glands compared with those from MD21–50 and HD21–50 dams, even after adjustment for fetal weight. Maternal nutrition also affected (P < 0.05) the weights of the fetal thyroid and brain. These results suggest that farmers can limit ewe nutrition in early pregnancy with only minor effects on the fetus. To investigate potential lifetime effects, a larger cohort of these animals is currently being monitored.
Livestock nutrition – a perspective on future needs in a resource-challenged planet
Authors: Hegarty R. S.
Published: May 2013

Global agriculture will be challenged by future population growth in the developing nations in Africa and Asia, concurrent with regional changes in climate that will adversely affect local crop and fodder production. The uncoupling of animal production from land area by global trade in high energy grains and protein meals, which has underpinned industrialised livestock production in the developed world, is forecast to continue in some population growth hotspots of the developing world. However, the projected rise in fossil fuel costs and the greenhouse gas emissions associated with their use will increasingly favour use of non-cereal energy sources, and the extent of feeding cereal grains to livestock in the developing world into the middle of this century is uncertain. Meeting the developing world’s growing demand for meat, milk and eggs in the face of the 3-fold challenge of population growth, climate change and fossil energy decline, demands a fresh vision, and the development of fresh technologies for animal nutrition in coming decades. How can high efficiency production be achieved from feeds of low metabolisability? This question is as critical for aquaculture as it is for land-based production. Enhancing ruminant capacity to generate animal product from crop by-products is fundamental in this achievement, but livestock access to crop residues will be in competition with the emerging second-generation (cellulosic) biofuels industry. Industrial technologies that treat crop residues to improve their nutritive value at source, not just as end-user treatments, will be required. There is scope to boost animal production and also reduce enteric greenhouse gas emissions (e.g. nitrate supplements) and the expanded capability in rumen microbiology may deliver targeted tools to mitigate emissions and increase energy yield from cellulosic feedstuffs. The greatest challenge of tomorrow’s nutritionist, however, is to provide local feed energy resources and enhanced nutrient utilisation, allowing a high yield of animal product without reliance on imported cereal grains and oilseed meals.
Restoration treatments improve seedling establishment in a degraded Mediterranean-type Eucalyptus ecosystem
Authors: Ruthrof Katinka X. , Douglas Tegan K. , Calver Michael C. , Barber Paul A. , Dell Bernard , Hardy Giles E. St. J.
Published: May 2013

Restoration of degraded Mediterranean-type ecosystems (MTEs) with long, hot and dry summers is challenging. To develop management guidelines, we evaluated techniques that could improve seedling establishment in two degraded Eucalyptus gomphocephala DC (tuart) woodlands, given weed and herbivore control. These techniques aimed to mimic favourable conditions for species that primarily recruit following disturbance events (e.g. fire). Trial 1 investigated the response of 5-month-old seedlings and broadcast seed in plots that contained a created ashbed, were ripped, or were ripped and contained an ashbed. Trial 2 examined the response of 5-month-old seedlings to treatments providing a nutrient or moisture source (slow-release fertiliser tablet, chelating agent, slow-release fertiliser tablet plus chelating agent, zeolite, hydrated hydrophilic co-polymers and dry hydrophilic co-polymers). Results indicated that created ashbeds enhance establishment for a range of species and reduce weed cover, with or without ripping. Broadcast seeding was not successful in returning species to site. Higher growth rates were recorded in seedlings treated with a nutrient source. The present study has shown that it is possible to re-establish local plant species in degraded woodlands through several techniques that mimic disturbance (e.g. fire). Strong early growth may be the vital start seedlings need in MTEs in the face of reinvading weed species, herbivory and a drying climate.
Reproductive biology of Monttea aphylla (Scrophulariaceae)
Authors: Tadey Mariana
Published: May 2013

Monttea aphylla is an aphyllus shrub abundant in the Monte Desert, Argentina. This species presents particular floral syndromes including violet, tubular flowers with trichome elaiophores that produce oil. Oil flowers are associated with specialised bees with an oil-collecting apparatus. To better understand the reproductive biology of M. aphylla, the mating system, flowering phenology, the associated pollinator assemblage and foraging behaviour was determined at the southern-most part of its distributional range. Results were compared with those of previous studies and discussed. At this southern location M. aphylla is a self-incompatible species; it relies on pollinators for fruit production and presented a low fruit set. Flowering occurred during the spring, from October to December. M. aphylla was pollinated by three species of bees (Apidae); two generalist species (Centris brethesi and Mesonychium jenseni) and one specialist to M. aphylla (Centris vardyorum). M. jenseni is a cleptoparasite of Centris species. Centris species are oil-collecting bees and showed territorial behaviour (i.e. they always visited a restricted group of plants which they protected from other visitors), they visited several flowers/plants, which enhanced geitonogamous self-pollination and reduced pollination efficiency, and which might explain the low natural fruit set observed in M. aphylla. C. vardyorum was the most important pollinator of M. aphylla in the study area. The reproductive biology of M. aphylla differs along its distributional range. Apparently, southern populations of M. aphylla are more specialised than the northern populations, the former being pollinated by a few related pollinator species whereas at the northern location a variety of visitors were observed.
Fertilisation residues alter leaf scleromorphy in an evergreen savannah shrub (Maprounea brasiliensis, Euphorbiaceae)
Authors: Delgado Marina Neves , Gomes Misléia Rodrigues de Aguiar , Báo Sônia Nair , Rossatto Davi Rodrigo
Published: May 2013

In the present study, we examined how residues of nitrogen (N), phosphorus (P) and calcium (Ca) fertilisers affect leaf anatomical traits in Maprounea brasiliensis (Euphorbiaceae), a typical and dominant cerrado (Brazilian savannah) species adapted to dystrophic soils. We predicted that fertiliser residues would alter qualitative and quantitative aspects of M. brasiliensis leaves and would decrease their scleromorphy. Leaves were sampled from plants that were growing in soils previously fertilised with N, P and Ca and in plants that were growing in soils without fertiliser residues. We measured the thickness of the cuticle, the epidermis of adaxial and abaxial surfaces, thickness of palisade parenchyma and spongy parenchyma, total thickness of the leaf, total area of the midrib and leaf mass per area (LMA). We found that plants under fertiliser residues produced fewer scleromorphic leaves with low LMA, thinner cuticle and epidermis and thicker palisade and spongy parenchyma. They also showed a decrease in the size and area occupied by the leaf midvein. However, plants under fertiliser residues produced similar leaf thickness as did the plants in the control group. Our results showed that residual effects of fertilisation changed structural patterns of a typical species of cerrado. Thus, further studies about fertilisation effects on leaf traits are needed because larger areas of the central cerrado are being occupied for agricultural production.
Substituted Phosphorous Triazatetrabenzocorroles: Correlation Between Structure and Excited State Properties
Authors: Zhang Xian-Fu , Chang Yakuan , Peng Yanling , Zhang Fushi
Published: May 2013

The photophysical properties of five novel phthalocyanine analogues, dihydroxy phosphorus(v) triazatetrabenzocorrole (PTBC) substituted with –NO2, –SO3H, OiPr, and –NH2, respectively, were studied by a combination of absorption, steady-state emission, time-resolved fluorescence, and laser flash photolysis. All substituents, even for the strong electron-donating –NH2, cause only a slight red shift of their absorption and emission maxima. These complexes are generally monomeric in organic solution, whereas the sulfonated derivative, PTBC(SO3H)4, slightly aggregates in aqueous buffer. Distinct from phthalocyanines, PTBCs substituted with –NO2 or –NH2 still show high photo activities. The electron-withdrawing –NO2 and –SO3H decrease the fluorescence quantum yield but increase the triplet formation yield to 0.76 and 0.82, respectively. All PTBCs have long triplet lifetimes and hence generate singlet oxygen efficiently with a quantum yield from 0.43 to 0.75. Together with the ground-state absorption properties, the results suggest that these PTBCs may be used as excellent photosensitizers for photodynamic therapy.
Structure Correlation Study of Some Diels–Alder Cycloadducts of Anthracene
Authors: Goh Yit W. , White Jonathan M.
Published: May 2013

Crystal structures of some Diels–Alder cycloadducts of anthracene and a variety of dienophiles reveal structural effects consistent with the manifestation of the early stages of the retro Diels–Alder reaction in the ground state structure. The symmetrical cycloadducts 3 and 4 reveal a qualitative relationship between structure and reactivity, whereas the cycloadducts of 9-methoxyanthracene show structural effects suggestive of the early stages of an asynchronous retro Diels–Alder reaction.
Synthesis of an Isotopically-labelled Antarctic Fish Antifreeze Glycoprotein Probe
Authors: Wojnar Joanna M. , Evans Clive W. , DeVries Arthur L. , Brimble Margaret A.
Published: May 2013

Antifreeze glycoproteins (AFGPs) are glycosylated polypeptides produced by Antarctic and Arctic fishes, which allow them to survive in seawater at sub-zero temperatures. An investigation into the postulated enteric uptake of AFGP synthesized in the exocrine pancreas of Antarctic fishes required a custom-prepared AFGP probe that incorporated seven isotopically-labelled Ala residues for detection by mass spectrometry. The AFGPs are composed of a repetitive three amino acid unit (Ala-Ala-Thr), in which the threonine residue is glycosylated with the disaccharide β-d-Gal-(1→3)-α-d-GalNAc. The synthesis of isotopically-labelled AFGP8 (1), as well as the optimized synthesis of the protected glycosylated amino acid building block 2, is reported.
Towards Conducting Metal-Organic Frameworks
Authors: D'Alessandro Deanna M. , Kanga Jehan R. R. , Caddy James S.
Published: May 2013

The realization of metal-organic frameworks (MOFs) as electronic conductors is a highly sought after goal, which has the potential to revolutionize the areas of catalysis, solid-state sensors and solar energy conversion devices. To date, the design and synthesis of MOFs that exhibit through-framework conduction has been limited; however, significant interest is now emerging owing to the fascinating prospects for integrating multiple functions. This highlight article introduces the field of conducting nanoporous materials and discusses recent specific examples along with key design features that will underlie future developments in the area.
Disordered Mesoporous Gadolinosilicate Nanoparticles Prepared Using Gadolinium Based Ionic Liquid Emulsions: Potential as Magnetic Resonance Imaging Contrast Agents
Authors: Liu Guozhen , Tse Nicholas M. K. , Hill Matthew R. , Kennedy Danielle F. , Drummond Calum J.
Published: May 2013

Gadolinium doped mesoporous silica (gadolinosilicate) nanoparticles were synthesized using a novel approach aimed at incorporating Gd ions into a porous silica network. The ionic liquid, gadolinium (Z)-octadec-9-enoate (Gd Oleate) was utilized in a dual role, as a soft template to generate porous silica and also to act as a gadolinium source for incorporation into the silicate. The generated silicate materials were characterized for size, structure and composition, confirming that gadolinium was successfully doped into the silicate network in a mesoporous nanoparticulate form. Proton relaxivity results indicated that the gadolinium doped silicates had slightly lower longitudinal relaxivity and much higher transverse relaxivity than the commercial contrast agent Magnevist®, suggesting that the mesoporous nanoparticulate materials have potential as contrast agents for magnetic resonance imaging.
A Review of Catalytic Systems for Glycerol Oxidation: Alternatives for Waste Valorization
Authors: Beltrán-Prieto Juan Carlos , Kolomazník Karel , Pecha Jiří
Published: May 2013

Endeavours leading to the study of glycerol oxidation result from the imperative necessity for wise utilization of surplus glycerine generated as by-product from biodiesel manufacture. The oxidation of glycerol is one of the most promising reactions as it leads to the generation of valuable glycerol derivatives that find broad application in pharmaceutical, polymer, and food industries. This review highlights the processing alternatives for glycerol by means of biocatalyst-mediated, heterogeneous, homogeneous, and electrochemical oxidation. The current state of the art is evaluated and recommendations for further research and future directions are included.
Sensors and imaging techniques for the assessment of the delay of wheat senescence induced by fungicides
Authors: Berdugo Carlos Andres , Mahlein Anne-Katrin , Steiner Ulrike , Dehne Heinz-Wilhelm , Oerke Erich-Christian
Published: May 2013

Near-range and remote sensing techniques are excellent alternatives to destructive methods for measuring beneficial effects of fungicides on plant physiology. Different noninvasive sensors and imaging techniques have been used and compared to measure the effects of three fungicidal compounds (bixafen, fluoxastrobin and prothioconazole) on wheat (Triticum aestivum L.) physiology under disease-free conditions in the greenhouse. Depending on the fungicidal treatment, changes in green leaf area and yield parameters were observed. Chlorophyll fluorescence of leaves was useful for measuring differences in the effective quantum yield of PSII. Reflectance measurements of wheat leaves were highly sensitive to changes in plant vitality. The spectral vegetation indices were useful for determining the differences among treatments in terms of leaf senescence, pigments and water content. The analysis of ear and leaf surface temperature was reliable for detecting effects of fungicides on plant senescence. Using nondestructive sensors, it was possible to assess a delay in senescence of wheat due to fungicide application. Furthermore, it was deduced that sensors and imaging methods are useful tools to estimate the effects of fungicides on wheat physiology. Physiological parameters measured by the sensors were actually more sensitive than yield parameters to assess the effect caused by fungicide application on wheat physiology.
Phylogenetic relationships of the spider family Psechridae inferred from molecular data, with comments on the Lycosoidea (Arachnida : Araneae)
Authors: Bayer Steffen , Schönhofer Axel L.
Published: May 2013

We investigated the relative phylogenetic position of the spider genera Psechrus Thorell, 1878 and Fecenia Simon, 1887 comprising the family Psechridae Simon, 1890 within the order Araneae (plus 50 outgroup taxa) using molecular data of the nuclear 28S rRNA gene and the mitochondrial cytochrome c oxidase subunit I (COI) gene. We further revised the placement of genera formerly hypothesised in Psechridae and tested morphological species and species-group hypotheses recently proposed for Psechrus and Fecenia. Our results showed both genera as monophyletic and included within Lycosoidea but indicated no support for a monophyletic family Psechridae. Support for relationships to particular genera of other families (Lycosidae, Pisauridae) was found to be equally low. Previous removal of the genera Stiphidion Simon, 1902, Poaka Forster & Wilton, 1973, Tengella Dahl, 1901 (Metafecenia F. O. Pickard-Cambridge, 1902) and Themacrys Simon, 1906 from Psechridae is confirmed by recovering most of them outside Lycosoidea. For Tengella (part of Lycosoidea) a close relation to Psechridae is not supported. In the species-rich genus Psechrus, morphologically predefined species groups were generally recovered as monophyletic. COI information was applied to test the morphological species hypotheses for 28 Psechridae species, most of them represented by more than one specimen. Our analyses corroborated all proposed species and indicated COI as reliable for barcoding both Psechrus and Fecenia. COI enabled assignment of a juvenile specimen to Fecenia protensa, establishing the first species record for Brunei.
Relationships between land use and nitrogen and phosphorus in New Zealand lakes
Authors: Abell Jonathan M. , Özkundakci Deniz , Hamilton David P. , Miller Steven D.
Published: May 2013

Developing policies to address lake eutrophication requires an understanding of the relative contribution of different nutrient sources and of how lake and catchment characteristics interact to mediate the source–receptor pathway. We analysed total nitrogen (TN) and total phosphorus (TP) data for 101 New Zealand lakes and related these to land use and edaphic sources of phosphorus (P). We then analysed a sub-sample of lakes in agricultural catchments to investigate how lake and catchment variables influence the relationship between land use and in-lake nutrients. Following correction for the effect of co-variation amongst predictor variables, high producing grassland (intensive pasture) was the best predictor of TN and TP, accounting for 38.6% and 41.0% of variation, respectively. Exotic forestry and urban area accounted for a further 18.8% and 3.6% of variation in TP and TN, respectively. Soil P (representing naturally-occurring edaphic P) was negatively correlated with TP, owing to the confounding effect of pastoral land use. Lake and catchment morphology (zmax and lake : catchment area) and catchment connectivity (lake order) mediated the relationship between intensive pasture and in-lake nutrients. Mitigating eutrophication in New Zealand lakes requires action to reduce nutrient export from intensive pasture and quantifying P export from plantation forestry requires further consideration.
Influence of Excited Molecules on Electron Swarm Transport Coefficients and Gas Discharge Kinetics
Authors: Petrovi Zoran Lj. , Vrhovac Slobodan B. , Jovanovi Jasmina V. , Raspopovi Zoran M. , Bzeni Svetlan A.
Published: May 2013

In this paper we study different effects of excited molecules on swarm
parameters, electron energy distribution functions and gas discharge modeling.
First we discuss a possible experiment in parahydrogen to resolve the
discrepancy in hydrogen vibrational excitation cross section data. Negative
differential conductivity (NDC) is a kinetic phenomenon which manifests itself
in a particular dependence of the drift velocity on E/N
and it is affected by superelastic collisions with excited states. A complete
kinetic scheme for argon required to model excited state densities in gas
discharges is also described. These results are used to explain experiments in
capacitively and inductively coupled RF plasmas used for processing. The paper
illustrates the application of atomic and molecular collision data, swarm data
and the theoretical techniques in modeling of gas discharges with large
abundances of excited molecules. It is pointed out that swarm experiments with
excited molecules are lacking and that there is a shortage of reliable data,
while the numerical procedures are sufficiently developed to include all the
important effects.
Quantum Electrodynamics in Strong Magnetic Fields. I. Electron States
Authors: Melrose DB , Parle AJ
Published: May 2013

Dirac's equation in the presence of a static magnetic field is solved in terms of both cartesian and cylindrical coordinates, and solutions are found for three different spin operators. Choosing the spin to correspond to the parallel component Ilz of the magnetic moment operator leads to wavefunctions (a) which are symmetric between electron and positron states and (b) which are eigenfunctions of the Hamiltonian including radiative corrections. A vertex function [y:',~(k)l~ is defined and shown to be proportional to a gauge independent quantity [T::~(k)l". Symmetry properties of [T~:~(k)l~ are derived in the case where the spin corresponds to Ilz. The use of the vertex function is illustrated by deriving the electron propagator in coordinate space from the vacuum expectation value. Properties of functions J~, _n(x) which appear extensively and are related to generalized Laguerre polynomials are derived and summarized in the Appendix.
Boltzmann Equation Theory of Charged Particle Transport in Neutral Gases: Perturbation Treatment
Authors: Vrhovac Slobodan B. , Petrovic Zoran Lj.
Published: May 2013

This paper examines the formal structure of the Boltzmann equation (BE) theory
of charged particle transport in neutral gases. The initial value problem of
the BE is studied by using perturbation theory generalised to non-Hermitian
operators. The method developed by R�sibois was generalised in order to
be applied for the derivation of the transport coecients of swarms of charged
particles in gases. We reveal which intrinsic properties of the operators
occurring in the kinetic equation are sucient for the generalised diffusion
equation (GDE) and the density gradient expansion to be valid. Explicit
expressions for transport coecients from the (asymmetric) eigenvalue problem
are also deduced. We demonstrate the equivalence between these microscopic
expressions and the hierarchy of kinetic equations. The establishment of the
hydrodynamic regime is further analysed by using the time-dependent
perturbation theory. We prove that for times t ?
τ0
(τ0 is the relaxation time),
the one-particle distribution function of swarm particles can be transformed
into hydrodynamic form. Introducing time-dependent transport coecients
?
*(p)
(?q,t), which can be related
to various Fourier components of the initial distribution function, we also
show that for the long-time limit all ?
*(p)
(?q,t) become time and
?q independent in the same
characteristic time and achieve their hydrodynamic values.