359 research outputs found
Long–term hay meadow management maintains the target community despite local-scale species turnover
Hay meadows, which are managed using a low intensity regime, are characterised by highly diverse vegetation but have declined significantly since the mid twentieth century. Remaining species-rich meadows are often protected by statutory designations and conservation management agreements. However, long-term studies of change in the composition of meadow vegetation, and investigations of the success of conservation over the long-term are rare. Fourteen sites, which had a long history of being managed for field dried hay, were resurveyed after 25 years and redundancy analysis was undertaken to investigate changes in community composition. Investigations of the effect of soil conditions, site size and spatial distribution of the meadow sites were carried out. Although overall community composition had changed significantly, the suite of species representative of the meadow community had been maintained, and species usually associated with more intensively managed grasslands had declined. However, there were losses of particular species of conservation importance such as Alchemilla glabra and Conopodium majus, and losses and gains of species varied from site to site. There was a significant increase in the homogeneity of the meadow vegetation between the two survey years. Comparisons of indicators of soil conditions suggested that there had been no significant change for the community as a whole but analyses of the species showing the most change indicated a decrease in soil fertility. Low intensity management has been successful in maintaining the meadow community but consideration of changes in key species and losses at the site level is needed. More research is needed to establish whether fragmentation is starting to have an impact on diversity
Polycystic ovary syndrome
The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Polycystic ovary syndrome (PCOS) affects 5-20% of women of reproductive age worldwide. The condition is characterized by hyperandrogenism, ovulatory dysfunction and polycystic ovarian morphology (PCOM) - with excessive androgen production by the ovaries being a key feature of PCOS. Metabolic dysfunction characterized by insulin resistance and compensatory hyperinsulinaemia is evident in the vast majority of affected individuals. PCOS increases the risk for type 2 diabetes mellitus, gestational diabetes and other pregnancy-related complications, venous thromboembolism, cerebrovascular and cardiovascular events and endometrial cancer. PCOS is a diagnosis of exclusion, based primarily on the presence of hyperandrogenism, ovulatory dysfunction and PCOM. Treatment should be tailored to the complaints and needs of the patient and involves targeting metabolic abnormalities through lifestyle changes, medication and potentially surgery for the prevention and management of excess weight, androgen suppression and/or blockade, endometrial protection, reproductive therapy and the detection and treatment of psychological features. This Primer summarizes the current state of knowledge regarding the epidemiology, mechanisms and pathophysiology, diagnosis, screening and prevention, management and future investigational directions of the disorder.Robert J Norman, Ruijin Wu and Marcin T Stankiewic
Recommended from our members
Effects of conversion of native cerrado vegetation to pasture on soil hydro-physical properties, evapotranspiration and streamflow on the Amazonian agricultural frontier
Understanding the impacts of land-use change on landscape-hydrological dynamics is one of the main challenges in the Northern Brazilian Cerrado biome, where the Amazon agricultural frontier is located. Motivated by the gap in literature assessing these impacts, we characterized the soil hydro-physical properties and quantified surface water fluxes from catchments under contrasting land-use in this region. We used data from field measurements in two headwater micro-catchments with similar physical characteristics and different land use, i.e. cerrado sensu stricto vegetation and pasture for extensive cattle ranching. We determined hydraulic and physical properties of the soils, applied ground-based remote sensing techniques to estimate evapotranspiration, and monitored streamflow from October 2012 to September 2014. Our results show significant differences in soil hydro-physical properties between the catchments, with greater bulk density and smaller total porosity in the pasture catchment. We found that evapotranspiration is smaller in the pasture (639 ± 31% mm yr-1) than in the cerrado catchment (1,004 ± 24% mm yr-1), and that streamflow from the pasture catchment is greater with runoff coefficients of 0.40 for the pasture and 0.27 for the cerrado catchment. Overall, our results confirm that conversion of cerrado vegetation to pasture causes soil hydro-physical properties deterioration, reduction in evapotranspiration reduction, and increased streamflow
Projected Range Contractions of European Protected Oceanic Montane Plant Communities: Focus on Climate Change Impacts Is Essential for Their Future Conservation
Global climate is rapidly changing and while many studies have investigated the potential impacts of this on the distribution of montane plant species and communities, few have focused on those with oceanic montane affinities. In Europe, highly sensitive bryophyte species reach their optimum occurrence, highest diversity and abundance in the northwest hyperoceanic regions, while a number of montane vascular plant species occur here at the edge of their range. This study evaluates the potential impact of climate change on the distribution of these species and assesses the implications for EU Habitats Directive-protected oceanic montane plant communities. We applied an ensemble of species distribution modelling techniques, using atlas data of 30 vascular plant and bryophyte species, to calculate range changes under projected future climate change. The future effectiveness of the protected area network to conserve these species was evaluated using gap analysis. We found that the majority of these montane species are projected to lose suitable climate space, primarily at lower altitudes, or that areas of suitable climate will principally shift northwards. In particular, rare oceanic montane bryophytes have poor dispersal capacity and are likely to be especially vulnerable to contractions in their current climate space. Significantly different projected range change responses were found between 1) oceanic montane bryophytes and vascular plants; 2) species belonging to different montane plant communities; 3) species categorised according to different biomes and eastern limit classifications. The inclusion of topographical variables in addition to climate, significantly improved the statistical and spatial performance of models. The current protected area network is projected to become less effective, especially for specialised arctic-montane species, posing a challenge to conserving oceanic montane plant communities. Conservation management plans need significantly greater focus on potential climate change impacts, including models with higher-resolution species distribution and environmental data, to aid these communities’ long-term survival
Effect of chitosan essential oil films on the storage-keeping quality of pork meat products
Edible films based on chitosan were prepared, with
and without basil or thyme essential oils, with the aim of
assessing their protective ability against lipid oxidation and
their antimicrobial activity. Chitosan films had good oxygenbarrier
properties, which were worsened by essential oil addition,
especially when the film equilibrium moisture content
increased. Due to the oxygen-barrier effect, all the films
effectively protected pork fat from oxidation, in comparison
to unprotected samples. In spite of the worsening of the
oxygen-barrier properties, the films with essential oils were
more effective than those of pure chitosan, which points to the
chemical action of specific antioxidant compounds of the oils.
Films were effective to control microbial growth in minced
pork meat, although the incorporation of essential oils did not
improve their antimicrobial activity. Throughout the storage,
the films led to colour changes in minced pork meat associated
with the conversion of myoglobin into metmyoglobin due to
the reduction of the oxygen availability.The authors acknowledge the financial support provided by the Universitat Politecnica de Valencia (PAID-06-09-2834), Generalitat Valenciana (GV/2010/082) and Ministerio de Educacion y Ciencia (AGL2010-20694). Author J. Bonilla is deeply grateful to Generalitat Valenciana for a Santiago Grisolia Grant.Bonilla Lagos, MJ.; Vargas, M.; Atarés Huerta, LM.; Chiralt Boix, MA. (2014). Effect of chitosan essential oil films on the storage-keeping quality of pork meat products. Food and Bioprocess Technology. 7(8):2443-2450. https://doi.org/10.1007/s11947-014-1329-3S2443245078ASTM D3985. (1995). Standard test method for oxygen gas transmission rate through plastic films and sheeting using a coulometric sensor. West Conshohocken: American Society for Testing and Materials.Atarés, L., Pérez-Masiá, R., & Chiralt, A. (2011). The role of some antioxidants in the HPMC film properties and lipid protection in coated toasted almonds. Journal of Food Engineering, 104, 649–656.Aureli, P., Costantini, A., & Zolea, S. (1992). Antimicrobial activity of some plant essential oils against Listeria monocytogenes. Journal of Food Protection, 55, 344–348.Baranauskiene, R., Venskutoni, S. P. R., Viskelis, P., & Dambrauskiene, E. (2003). Influence of nitrogen fertilizers on the yield and composition of thyme (Thymus vulgaris). Journal of Agricultural and Food Chemistry, 51, 7751–7758.Bonilla, J., Atarés, L., Vargas, M., & Chiralt, A. (2012a). Edible films and coatings to prevent the detrimental effect of oxygen on food quality: possibilities and limitations. Journal of Food Engineering, 110, 208–213.Bonilla, J., Atarés, L., Vargas, M., & Chiralt, A. (2012b). Effect of essential oils and homogenization conditions on properties of chitosan-based films. Food Hydrocolloids, 26, 9–16.Burt, S. (2004). Essential oils: their antibacterial properties and potential applications in foods—a review. International Journal of Food Microbiology, 94, 223–253.Burt, S. A., & Reinders, R. D. (2003). Antibacterial activity of selected plant essential oils against Escherichia coli O157:H7. Letters in Applied Microbiology, 36, 162–167.Caner, C., Vergano, P. J., & Wiles, J. L. (1998). Chitosan film mechanical and permeation properties as affected by acid, plasticizer and storage. Journal of Food Science, 63, 1049–1053.Casariego, A., Souza, B. W. S., Cerqueira, M. A., Teixeira, J. A., Cruz, L., Díaz, R., et al. (2009). Chitosan/clay ‘films properties as affected by biopolymer and clay micro/nanoparticles’ concentrations. Food Hydrocolloids, 23, 1895–1902.Devlieghere, F., Vermeiren, L., & Debevere, J. (2004). New preservation technologies: possibilities and limitations. International Dairy Journal, 14, 273–285.Di Pasqua, R., Hoskins, N., Betts, G., & Mauriello, G. (2006). Changes in membrane fatty acids composition of microbial cells induced by addiction of thymol, carvacrol, limonene, cinnamaldehyde and eugenol in the growing media. Journal of Agricultural and Food Chemistry, 54, 2745–2749.Di Pierro, P., Sorrentino, A., Mariniello, L., Giosafatto, C. V. L., & Porta, R. (2011). Chitosan/whey protein film as active coating to extend Ricotta cheese shelf-life. LWT--Food Science and Technology, 44, 2324–2327.Fabra, M. J., Talens, P., Gavara, R., & Chiralt, A. (2012). Barrier properties of sodium caseinate films as affected by lipid composition and moisture content. Journal of Food Engineering, 109(3), 372–379.Gaysinsky, S., Davidson, P. M., Bruce, B. D., & Weiss, J. (2005). Growth inhibition of E. Coli O157:H7 and Listeria monocytogenes by carvacrol and eugenol encapsulated in surfactant micelles. Journal of Food Protection, 68, 2559–2566.Govaris, A., Botsoglou, E., Sergelidis, D., & Chatzopoulou, P. D. (2011). Antibacterial activity of oregano and thyme essential oils against Listeria monocytogenes and Escherichia coli O157:H7 in feta cheese packaged under modified atmosphere. LWT - Food Science and Technology, 44, 1240–1244.Han, J. H., & Gennadios, A. (2005). Edible films and coatings: a review. In J. H. Han (Ed.), Innovations in Food Packaging (pp. 39–262). Oxford: Elsevier Academic.Kim, J., Marshall, M. R., & Wei, C. I. (1995). Antibacterial activity of some essential oil components against five foodborne pathogens. Journal of Agricultural and Food Chemistry, 43, 2839–2845.Labuza, T. P. (1980). The effect of water activity on reaction kinetics of food deterioration. Food Technology, 34, 36–41.Mancini, R. A., & Hunt, M. C. (2005). Current research in meat color. Meat Science, 71, 100–121.Moure, A., Cruz, J. M., Franco, D., Dominguez, J. M., Sineiro, J., Dominguez, H., et al. (2001). Natural antioxidants from residual sources. Food Chemistry, 72, 145–171.Rao, M. S., Chander, R., & Sharma, A. (2005). Development of shelf-stable intermediate moisture meat products using active edible chitosan coating and irradiation. Journal of Food Science, 70, 325–331.Salame, M. (1986). Barrier polymers. In M. Bakker (Ed.), The Wiley encyclopedia of packaging technology (pp. 48–54). New York: Wiley.Sánchez-González, L., González-Martínez, C., Chiralt, A., & Cháfer, M. (2010). Physical and antimicrobial properties of chitosan–tea tree essential oil composite films. Journal of Food Engineering, 98, 443–452.Sánchez-González, L., Vargas, M., González-Martínez, C., Chiralt, A., & Cháfer, M. (2011a). Use of essential oils in bioactive edible coatings. Food Engineering Reviews, 3, 1–16.Sánchez-González, L., Cháfer, M., Hernández, M., Chiralt, A., & González-Martínez, C. (2011b). Antimicrobial activity of polysaccharide films containing essential oils. Food Control, 22, 1302–1310.Seydim, A. C., & Sarikus, G. (2006). Antimicrobial activity of whey protein based edible films incorporated with oregano, rosemary and garlic essential oils. Food Research International, 39, 639–644.Shan, B., Cai, Y. Z., Sun, M., & Corke, H. (2005). Antioxidant capacity of 26 spice extracts and characterization of their phenolic constituents. Journal of Agricultural and Food Chemistry, 53, 7749–7759.Singh, B., Falahee, M. B., & Adams, M. R. (2001). Synergistic inhibition of Listeria monocytogenes by nisin and garlic extract. Food Microbioliology, 18, 133–139.Vargas, M., Albors, A., Chiralt, A., & González-Martínez, C. (2006). Quality of cold-stored strawberries as affected by chitosan–oleic acid edible coatings. Postharvest Biology and Technology, 41, 164–171.Vargas, M., Albors, A., Chiralt, A., & González-Martínez, C. (2009). Characterization of chitosan–oleic acid composite films. Food Hydrocolloids, 23, 536–547.Vargas, M., Albors, A., & Chiralt, A. (2011). Application of chitosan-sunflower oil edible films to pork meat hamburgers. Procedia Food Science, 1, 39–43.Wan, J., Wilcock, A., & Coventry, M. J. (1998). The effect of essential oils of basil on the growth of Aeromonas hydrophila and Pseudomonas fluorescens. Journal of Applied Microbiology, 84, 152–158.Zivanovic, S., Chi, S., & Draughon, F. (2005). Antimicrobial activity of chitosan films enriched with essential oils. Journal of Food Science, 70, 45–51
Coral Colonisation of an Artificial Reef in a Turbid Nearshore Environment, Dampier Harbour, Western Australia
A 0.6 hectare artificial reef of local rock and recycled concrete sleepers was constructed in December 2006 at Parker Point in the industrial port of Dampier, western Australia, with the aim of providing an environmental offset for a nearshore coral community lost to land reclamation. Corals successfully colonised the artificial reef, despite the relatively harsh environmental conditions at the site (annual water temperature range 18-32°C, intermittent high turbidity, frequent cyclones, frequent nearby ship movements). Coral settlement to the artificial reef was examined by terracotta tile deployments, and later stages of coral community development were examined by in-situ visual surveys within fixed 25 x 25 cm quadrats on the rock and concrete substrates. Mean coral density on the tiles varied from 113 ± 17 SE to 909 ± 85 SE per m2 over five deployments, whereas mean coral density in the quadrats was only 6.0 ± 1.0 SE per m2 at eight months post construction, increasing to 24.0 ± 2.1 SE per m2 at 62 months post construction. Coral taxa colonising the artificial reef were a subset of those on the surrounding natural reef, but occurred in different proportions-Pseudosiderastrea tayami, Mycedium elephantotus and Leptastrea purpurea being disproportionately abundant on the artificial reef. Coral cover increased rapidly in the later stages of the study, reaching 2.3 ± 0.7 SE % at 62 months post construction. This study indicates that simple materials of opportunity can provide a suitable substrate for coral recruitment in Dampier Harbour, and that natural colonisation at the study site remains sufficient to initiate a coral community on artificial substrate despite ongoing natural and anthropogenic perturbations. © 2013 Blakeway et al
Recommended from our members
Changes in the variability and periodicity of precipitation in Scotland
This paper analyses the temporal and spatial changes in the amount and variability of rainfall in Scotland. The
sequential Mann–Kendall test reveals that total annual precipitation has increased across Scotland since the 1970s with
increasing trends in variability beginning between the mid-1960s and the mid-1970s. Whilst temporally consistent
increasing trends in precipitation totals prevail in the West, many weather stations in the East have experienced
subsequent trend turning points in the following two decades, explaining the larger magnitude of the trends in western Scotland in recent decades. Trend analyses on six measures of rainfall variability indicate an increase in rainfall variability during the period 1961–2000, as measured by the intra-annual variance, the winter to summer precipitation ratio and the annual cumulative sum range, with decreasing trends observed in the number of dry days. Periodicities associated with
the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation could explain the observed temporal variability of
rainfall
COPD exacerbations in general practice: variability in oral prednisolone courses
<p>Abstract</p> <p>Background</p> <p>The use of oral corticosteroids as treatment of COPD exacerbations in primary care is well established and evidence-based. However, the most appropriate dosage regimen has not been determined and remains controversial. Corticosteroid therapy is associated with a number of undesirable side effects, including hyperglycaemias, so differences in prescribing might be relevant. This study examines the differences between GPs in dosage and duration of prednisolone treatment in patients with a COPD exacerbation. It also investigates the number of general practitioners (GPs) who adjust their treatment according to the presence of diabetic co-morbidity.</p> <p>Methods</p> <p>Cross-sectional study among 219 GPs and 25 GPs in training, located in the Northern part of the Netherlands.</p> <p>Results</p> <p>The response rate was 69%. Nearly every GP prescribed a continuous dose of prednisolone 30 mg per day. Among GPs there were substantial differences in treatment duration. GPs prescribed courses of five, seven, ten, or fourteen days. A course of seven days was most common. The duration of treatment depended on exacerbation and disease severity. A course of five days was especially prescribed in case of a less severe exacerbation. In a more severe exacerbation duration of seven to fourteen days was more common. Hardly any GP adjusted treatment to the presence of diabetic co-morbidity.</p> <p>Conclusion</p> <p>Under normal conditions GPs prescribe prednisolone quite uniformly, within the range of the current Dutch guidelines. There is insufficient guidance regarding how to adjust corticosteroid treatment to exacerbation severity, disease severity and the presence of diabetic co-morbidity. Under these circumstances, there is a substantial variation in treatment duration.</p
- …
