Trade-offs between succulent and non-succulent epiphytes underlie variation in drought tolerance and avoidance.

Epiphyte communities comprise important components of many forest ecosystems in terms of biomass and diversity, but little is known regarding trade-offs that underlie diversity and structure in these communities or the impact that microclimate has on epiphyte trait allocation. We measured 22 functional traits in vascular epiphyte communities across six sites that span a microclimatic gradient in a tropical montane cloud forest region in Costa Rica. We quantified traits that relate to carbon and nitrogen allocation, gas exchange, water storage, and drought tolerance. Functional diversity was high in all but the lowest elevation site where drought likely limits the success of certain species with particular trait combinations. For most traits, variation was explained by relationships with other traits, rather than differences in microclimate across sites. Although there were significant differences in microclimate, epiphyte abundance, and diversity, we found substantial overlap in multivariate trait space across five of the sites. We found significant correlations between functional traits, many of which related to water storage (leaf water content, leaf thickness, hydrenchymal thickness), drought tolerance (turgor loss point), and carbon allocation (specific leaf area, leaf dry matter content). This suite of trait correlations suggests that the epiphyte community has evolved functional strategies along with a drought avoidance versus drought tolerance continuum where leaf succulence emerged as a pivotal overall trait.

Technique and protocols for cardiothoracic time-resolved contrast-enhanced magnetic resonance angiography sequences: a systematic review.

AIM: To review contrast medium administration protocols used for cardiothoracic applications of time-resolved, contrast-enhanced magnetic resonance angiography (MRA) sequences. MATERIALS AND METHODS: A systematic search of the literature (Medline/EMBASE) was performed to identify articles utilising time-resolved MRA sequences, focusing on type of sequence, adopted technical parameters, contrast agent (CA) issues, and acquisition workflow. Study design, year of publication, population, magnetic field strength, type, dose, and injection parameters of CA, as well as technical parameters of time-resolved MRA sequences were extracted. RESULTS: Of 117 retrieved articles, 16 matched the inclusion criteria. The study design was prospective in 9/16 (56%) articles, and study population ranged from 5 to 185 patients, for a total of 506 patients who underwent cardiothoracic time-resolved MRA. Magnetic field strength was 1.5 T in 13/16 (81%), and 3 T in 3/16 (19%) articles. The administered CA was gadobutrol (Gadovist) in 6/16 (37%) articles, gadopentetate dimeglumine (Magnevist) in 5/16 (31%), gadobenate dimeglumine (MultiHance) in 2/16 (13%), gadodiamide (Omniscan) in 2/16 (13%), gadofosveset trisodium (Ablavar, previously Vasovist) in 1/16 (6%). CA showed highly variable doses among studies: fixed amount or based on patient body weight (0.02-0.2 mmol/kg) and was injected with a flow rate ranging 1-5 ml/s. Sequences were TWIST in 13/16 (81%), TRICKS in 2/16 (13%), and CENTRA 1/16 articles (6%). CONCLUSION: Time-resolved MRA sequences were adopted in different clinical settings with a large spectrum of technical approaches, mostly in association with different CA dose, type, and injection method. Further studies in relation to specific clinical indications are warranted to provide a common standardised acquisition protocol.

Patient's posteroanterior chest radiographs are routinely displayed at different sizes on PACS: Cause and prevalence.

OBJECTIVE: Sequential posteroanterior chest radiographs (CXRs) on any one patient are commonly displayed at different sizes on PACS monitors. The purpose of this study was to determine the cause of these differences, the percentage of radiographs affected, the relative change in magnification seen and if radiologists were aware of this display difference. METHODS: Differences in routine radiographer collimation pre-acquisition and image cropping (shuttering) post acquisition were noted. From three different hospitals, 300 posteroanterior (PA) erect CXRs with prior comparative studies were viewed side-by-side on a standard landscape display monitor. Variation in display size was calculated using the number of detector elements in the autofitted axis of the radiograph, when compared with the prior study. Correlation between patient gender and extent of magnification between images was recorded. Following this, a national survey was circulated to see if radiologists were aware of this phenomenon. RESULTS: Large variations in display size were noted. The mean extent of magnification between sequential PA chest radiographs was ±6.8% (range 0-21.6%). 98% of CXRs had some degree of variability in display size. There was no significant difference in the extent of variation in magnification based on age or gender. 86% of the radiologists who responded to the survey (n = 132) were unaware of any display size variability. CONCLUSION: Sequential DR acquired chest radiographs are routinely displayed with varying degrees of magnification on PACS monitors due to differences in radiographer practice and auto-fit display settings. Most radiologists surveyed were unaware of these differences and their causation.

Change from transrectal to transperineal ultrasound-guided prostate biopsy under local anaesthetic eliminates sepsis as a complication.

Transrectal ultrasound-guided (TRUS) biopsy of the prostate is associated with increased risk of post-procedural sepsis with associated morbidity, mortality, re-admission to hospital, and increased healthcare costs. In the study institution, active surveillance of post-procedural infection complications is performed by clinical nurse specialists for prostate cancer under the guidance of the infection prevention and control team. To protect hospital services for acute medical admissions related to the coronavirus disease 2019 (COVID-19) pandemic, TRUS biopsy services were reduced nationally, with exceptions only for those patients at high risk of prostate cancer. In the study institution, this change prompted a complete move to transperineal (TP) prostate biopsy performed in outpatients under local anaesthetic. TP biopsies eliminated the risk of post-procedural sepsis and, consequently, sepsis-related admission while maintaining a service for prostate cancer diagnosis during the COVID-19 pandemic.

Meticillin-resistant Staphylococcus aureus (MRSA) environmental contamination in a radiology department.

AIM: To explore the potential risk to patients and healthcare workers of acquiring meticillin-resistant Staphylococcus aureus (MRSA) in clinical and non-clinical areas within a radiology department. MATERIALS AND METHODS: High-risk sites in clinical and non-clinical areas within the Department of Radiology were identified and 125 environmental swabs were obtained by an infection control nurse specialist. Decontamination methods and protocols were reviewed and compared against international decontamination best practice. RESULTS: One of 125 samples was culture positive for MRSA. The positive sample was isolated from the surface of the bore of the magnetic resonance imaging (MRI) unit. A hypochlorite cleaning agent was applied using a long-handled brush to clean the bore of the MRI unit. A repeat environmental screen found the MRI unit to be culture negative for MRSA. CONCLUSION: This study has demonstrated that standard decontamination measures are adequate to prevent environmental contamination with MRSA in a radiology department. However, the MRI unit requires special attention because of its long bore and difficult access.

Subtraction of time-resolved magnetic resonance angiography images improves visualization of the pulmonary veins and left atrium in adults with congenital heart disease: a novel post-processing technique.

To describe a novel time-resolved magnetic resonance angiography (TR-MRA) postprocessing technique using the time-resolved angiography with interleaved stochastic trajectories (TWIST) method to evaluate the pulmonary veins and left atrium in adults with congenital heart disease undergoing cardiac MRI. Institutional ethics committee approved the study. 21 consecutive adult patients (14 female, 7 male patients, mean age 28 years) with known congenital heart disease who underwent a cardiac MRI were included. Post-processing of the TR-MRA sequences created novel "subtracted" datasets. Two independent observers reviewed the conventional TWIST and novel subtracted TWIST data sets in source and maximum intensity projection (MIP) coronal reformats to assess visualization of the pulmonary veins and left atrium based on a 5-point scale. Quantitative signal to noise (SNR) comparison was performed. TR-MRA yielded diagnostic image data in 20/21 patients (95.2%). The novel "subtracted" TR-MRA technique improved visualization of the pulmonary veins and left atrium compared to the source TR-MRA sequence in 16/20 patients (mean scores 3.34 ± 0.69 vs. 2.92 ± 0.69, p < 0.008). Further improved visualization of the pulmonary veins and left atrium was observed in the subtracted MIP TWIST sequences compared to the MIP TWIST images (mean scores 4.43 ± 0.80 vs. 3.02 ± 0.87 vs., p < 0.001). No significant SNR difference between the source and novel subtracted group was observed (85.4 vs. 70.4, p = 0.57). Compared to source TR-MRA images, subtraction of TR-MRA images is a novel postprocessing technique that improves visualization of the pulmonary veins and left atrium in a substantial number of patients.

Managing animal disease risk in Australia: the impact of climate change.

Climate change is one of a number of factors that are likely to affect the future of Australian agriculture, animal production and animal health, particularly when associated with other factors such as environmental degradation, intensive animal production, an increasing human population, and expanding urbanisation. Notwithstanding the harshness and variability of Australia's climate, significant livestock industries have been developed, with the majority of products from such industries exported throughout the world. A critical factor in achieving market access has been an enviable animal health status, which is underpinned by first class animal health services with a strong legislative basis, well-trained staff, engagement of industry, effective surveillance, good scientific and laboratory support, effective emergency management procedures, a sound quarantine system, and strong political support. However, enhancements still need to be made to Australia's animal health system, for example: re-defining the science-policy interface; refining foresight, risk analysis, surveillance, diagnostics, and emergency management; improving approaches to education, training, technology transfer, communications and awareness; and engaging more with the international community in areas such as capacity building, the development of veterinary services, and disease response systems. A 'one health' approach will be adopted to bring together skills in the fields of animal, public, wildlife and environmental health. These initiatives, if managed correctly, will minimise the risks resulting from global warming and other factors predisposing to disease.

The role of 3D printing in preoperative planning for heart transplantation in complex congenital heart disease.

BACKGROUND: The presence of a structural cardiac defect in the setting of dextrocardia is extremely rare. Graspable models allow enhanced appreciation of aberrant structures and vascular relations, particularly in rare and complex cases. This is the first case report of the use of a replica of a patients' anatomy to plan the surgical strategy in the setting of dextrocardia. AIMS: We intend to demonstrate the benefit of three-dimensional printing to enhance preoperative planning in complex congenital heart disease undergoing heart transplantation. The anomalous structures encountered include situs inversus dextrocardia, transposition of the great vessels, a single atrium and a dilated double-outlet single right ventricle. METHODS: Computed Tomography acquisition was performed with the use of ECG multiphase gating technology and contrast enhancement. The structures of interest were segmented and the generated 3D mesh was exported as a stereolithographic (STL) file. The model was printed on a Z-Corp 250 binder jetting printer. Post processing techniques were used to enhance model strength. RESULTS: Pre-operative 3D visualisation of the patients' anatomy allowed for a more comprehensive surgical strategy to be planned, thus reducing the intra-operative duration and cross-clamp time which are recognised to correlate with reduced patient morbidity. CONCLUSION: The ongoing advances in medical image procurement and 3D processing software and printing technology will continue to enhance preoperative planning and thereby improve patient care. We demonstrate the pivotal role played by such technologies in advancing spatial comprehension of complex aberrant anatomy.

Meeting the requirements of importing countries: practice and policy for on-farm approaches to food safety.

In light of the increasing consumer demand for safe, high-quality food and recent public health concerns about food-borne illness, governments and agricultural industries are under pressure to provide comprehensive food safety policies and programmes consistent with international best practice. Countries that export food commodities derived from livestock must meet both the requirements of the importing country and domestic standards. It is internationally accepted that end-product quality control, and similar methods aimed at ensuring food safety, cannot adequately ensure the safety of the final product. To achieve an acceptable level of food safety, governments and the agricultural industry must work collaboratively to provide quality assurance systems, based on sound risk management principles, throughout the food supply chain. Quality assurance systems on livestock farms, as in other parts of the food supply chain, should address food safety using hazard analysis critical control point principles. These systems should target areas including biosecurity, disease monitoring and reporting, feedstuff safety, the safe use of agricultural and veterinary chemicals, the control of potential food-borne pathogens and traceability. They should also be supported by accredited training programmes, which award certification on completion, and auditing programmes to ensure that both local and internationally recognised guidelines and standards continue to be met. This paper discusses the development of policies for on-farm food safety measures and their practical implementation in the context of quality assurance programmes, using the Australian beef industry as a case study.

Mediastinal lymph node size in an Asian population.

There is a high incidence of respiratory tuberculosis in the British population of Indian subcontinent (Asian) ethnic origin. Granulomatous diseases can cause long term lymph node enlargement. Separate computed tomography (CT) criteria for normal nodal size could therefore be necessary when staging thoracic malignancy in Asian patients. The objective of this study was to measure mediastinal lymph node size in an Asian population, and to correlate nodal size with previous tuberculosis. Chest CT scans on all Asian patients over a 5 year period were reviewed and those with pulmonary disease, malignancy or grossly distorted anatomy were excluded. The study group consisted of 48 patients (26 male, 22 female) aged 10-75 years (mean 47 years). All nodes were measured and the site of those greater than 7 mm was recorded using the American Thoracic Society (ATS) lymph node map. 81.3% of patients had nodes less than or equal to 7 mm at all ATS stations, 10.4% had nodes of 8-10 mm and 8.3% had nodes greater than 10 mm. All nodes measuring more than 7 mm were in regions 4R, 10R and 7. Fourteen patients had signs of previous tuberculosis, and in this group 50% had nodes greater than 7 mm as compared with 6% in the group with no signs of previous tuberculosis (p < 0.001, X2 test). Despite these differences only four of the 48 patients (8.3%) had nodes greater than 10 mm, which is in keeping with other general population studies. Thus the generally accepted size criteria for mediastinal lymph node enlargement (greater than 10 mm) can reasonably be applied to all Asian patients when staging lymphoma or bronchogenic carcinoma.

Assessment of mammographic film processor performance in a hospital and mobile screening unit.

In contrast to the majority of mammographic breast screening programmes, film processing at this centre occurs on site in both hospital and mobile trailer units. Initial (1989) quality control (QC) sensitometric tests revealed a large variation in film processor performance in the mobile unit. The clinical significance of these variations was assessed and acceptance limits for processor performance determined. Abnormal mammograms were used as reference material and copied using high definition 35 mm film over a range of exposure settings. The copies were than matched with QC film density variation from the mobile unit. All films were subsequently ranked for spatial and contrast resolution. Optimal values for processing time of 2 min (equivalent to film transit time 3 min and developer time 46 s) and temperature of 36 degrees C were obtained. The widespread anomaly of reporting film transit time as processing time is highlighted. Use of mammogram copies as a means of measuring the influence of film processor variation is advocated. Careful monitoring of the mobile unit film processor performance has produced stable quality comparable with the hospital based unit. The advantages of on site film processing are outlined. The addition of a sensitometric step wedge to all mammography film stock as a means of assessing image quality is recommended.

The American Thoracic Society lymph node map: a CT demonstration.

It is now a decade since the American Thoracic Society (ATS) lymph node map was first described. Recently it has been upgraded to include supraclavicular and superior diaphragmatic lymph nodes. By standardising terminology the map aids in the provision of a more valid data base to evaluate diagnostic techniques and therapeutic protocols. Despite these potential benefits the map has failed to gain widespread use amongst European radiologists. This essay illustrates the relationship of the nodal stations to normal anatomy utilizing calcified nodes on CT scans. The ease with which the map can be applied to cross-sectional anatomy is emphasized. It is hoped that the images will act as a teaching aid to promote greater acceptance and use of the ATS map. The relationship of the nodal stations to the new American Joint Classification of disease extent is also outlined.

Imaging of acute head injury.

This article reviews the neuroradiological evaluation of acute head injury with an emphasis on CT and MR imaging. Subacute and chronic head injury are not discussed. CT remains the modality of choice in the emergency setting, permitting rapid, comprehensive assessment of the great majority of head injuries. MR is most useful in patients in whom there is a discrepancy between clinical symptoms and CT findings. In addition, MR is the imaging modality of choice in the subacute and chronic setting. The superior contrast resolution of MR permits optimal evaluation of nonhemorrhagic (and hemorrhagic) white matter shearing injuries, and the lack of beam-hardening artifact permits a more thorough evaluation of the brain stem, posterior fossa, and cortical surface.

Quality assurance and meat inspection in Australia.

The aim of meat inspection in Australia is to contribute to the production of safe and wholesome food, comply with the requirements of importing countries, and support national animal health objectives. An analysis of the role of quality assurance (QA) in the meat inspection systems at federally inspected establishments shows that the position of Australia as a leading meat exporter is aided by a co-regulatory, QA-based approach to meat inspection, which is equally applicable to all species at slaughter. Technical developments in meat inspection at the national and international level during the 1990s led to significant enhancements in QA systems. Quality assurance is implemented through nationally uniform documented systems, which are designed to achieve consistent standards of meat safety. These systems are complemented by hazard analysis critical control point-based QA programmes which meet the quality-standards of the International Organization for Standardization. Quality assurance programmes aim for a 'whole of chain' approach, so that the system is implemented 'from the paddock to the plate', or from pre-harvest through to post-harvest, i.e., from on-farm practices to the refrigeration, storage and transportation stages. The QA elements of meat inspection employed in production systems in Australia have significantly contributed to the consistent achievement of meat safety objectives that are appropriate to contemporary risks.

Economic aspects of foot and mouth disease: perspectives of a free country, Australia.

Australia is a significant livestock producer and a major exporter of livestock, livestock products and livestock genetic material. An outbreak of foot and mouth disease (FMD) would have severe economic consequences on the economy. A recent study found that in an outbreak lasting six months, real gross domestic product in Australia would fall by an estimated 0.6% (AUS$3.5 billion), employment by 0.8%, and a depreciation of 3% would be recorded in the exchange rate in the first year. Much of this impact would be due to the loss of export markets. Given the significant consequences of an outbreak of FMD, Australia invests considerable resources in prevention and planning. These measures can be viewed at three levels, namely: pre-border, border and post-border. Australia recently further enhanced quarantine at the border to minimise the risk of entry of FMD. However, no matter how much is invested, there is no guarantee that FMD will not enter the country. Accordingly, it is important to ensure that comprehensive contingency plans are also in place. Recent outbreaks in previously free countries have shown that a large outbreak of FMD poses major problems for the animal health services of a country and a combined government and industry response is required.

Revised post-mortem inspection procedures for cattle and pigs slaughtered at Australian abattoirs.

Revised procedures for the post-mortem inspection of cattle and pigs at Australian abattoirs were developed as minimum national requirements. Comparative trials of current and revised procedures were conducted at 3 and 4 Australian abattoirs for pigs and cattle respectively. Residual pathological changes after inspection and removal of lesions from heads, carcases or viscera were recorded by an evaluation team with the data used to determine relative effectiveness. For cattle, there was no significant difference between current and revised procedures. Although it had been proposed to eliminate routine incision of cervical lymph nodes for pigs, it was found necessary to retain this procedure. The data also revealed a significant variation in detection of pathology between abattoirs for both species. Parasitic conditions accounted for the greatest proportion of undetected lesions in both species for both current and revised procedures. These comprised mainly fascioliasis in cattle and ascariasis in pigs. The former was associated with the study being conducted in eastern Australia. Chronic interstitial nephritis was also a common undetected lesion, reinforcing the need for intensified inspection of kidneys. However, such residual pathology was considered to be of only limited significance to human health. The revised procedures and findings are discussed in the context of animal and human health and of the importance of the meat industry to Australian exports. Some attention has been given to specific conditions likely to be affected by the proposals including tuberculosis, bovine cysticercosis, fascioliasis, porcine arthritis and salmonellosis. The role of meat inspection in monitoring for specific diseases is discussed.(ABSTRACT TRUNCATED AT 250 WORDS)