Continental-scale effects of nutrient pollution on stream ecosystem functioning     

Woodward G  Gessner MO  Giller PS  Gulis V  Hladyz S  Lecerf A  Malmqvist B  McKie BG  Tiegs SD  Cariss H  Dobson M  Elosegi A  Ferreira V  Graça MA  Fleituch T  Lacoursière JO  Nistorescu M  Pozo J  Risnoveanu G  Schindler M  Vadineanu A  Vought LB  Chauvet E 《Science (New York, N.Y.)》2012,336(6087):1438-1440

Excessive nutrient loading is a major threat to aquatic ecosystems worldwide that leads to profound changes in aquatic biodiversity and biogeochemical processes. Systematic quantitative assessment of functional ecosystem measures for river networks is, however, lacking, especially at continental scales. Here, we narrow this gap by means of a pan-European field experiment on a fundamental ecosystem process--leaf-litter breakdown--in 100 streams across a greater than 1000-fold nutrient gradient. Dramatically slowed breakdown at both extremes of the gradient indicated strong nutrient limitation in unaffected systems, potential for strong stimulation in moderately altered systems, and inhibition in highly polluted streams. This large-scale response pattern emphasizes the need to complement established structural approaches (such as water chemistry, hydrogeomorphology, and biological diversity metrics) with functional measures (such as litter-breakdown rate, whole-system metabolism, and nutrient spiraling) for assessing ecosystem health.  相似文献   

Treatment of sickle cell anemia mouse model with iPS cells generated from autologous skin   总被引：2，自引：0，他引：2  

Hanna J  Wernig M  Markoulaki S  Sun CW  Meissner A  Cassady JP  Beard C  Brambrink T  Wu LC  Townes TM  Jaenisch R 《Science (New York, N.Y.)》2007,318(5858):1920-1923

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Identifying risk factors of highly pathogenic avian influenza (H5N1 subtype) in Indonesia     

Loth L  Gilbert M  Wu J  Czarnecki C  Hidayat M  Xiao X 《Preventive veterinary medicine》2011,102(1):50-58

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Prevalence,species distribution and antimicrobial resistance patterns of methicillin-resistant staphylococci in Lithuanian pet animals     

Modestas Ruzauskas  Natacha Couto  Sigita Kerziene  Rita Siugzdiniene  Irena Klimiene  Marius Virgailis  Constan?a Pomba 《Acta veterinaria Scandinavica》2015,57(1)

Background

The bacterial genus Staphylococcus consists of many species that causes infections in pet animals. Antimicrobial resistant staphylococci cause infections that are difficult to treat and they are important from the point of one health perspective. The aim of this study was to determine the prevalence of methicillin-resistant Staphylococcus (MRS) species, including methicillin-resistant S. aureus (MRSA) in diseased pet animals (Group A) and kennel dogs (Group B) in Lithuania and to characterize the isolates according to their antimicrobial resistance.

Results

Twenty-one MRS isolates were obtained from 395 clinical samples (5.3 %; CI 95 % 3.5-8.0) of Group A animals. Sixteen, four and one isolates were from dogs, cats and a pet rabbit, respectively. The mecA gene was present in 20 isolates, whereas one isolate was positive for the mecC gene. Twenty-one MRS isolates (20.0 %; CI 95 % 13.5-28.6) were obtained from the vagina of female dogs (n = 105) (Group B). All isolates carried the mecA gene. Twelve MRS species were isolated of which S. pseudintermedius was the most common (18/42) followed by S. haemolyticus (8/42) and S. lentus (4/42). MRSA was not found. All MRS strains were susceptible to vancomycin, linezolid, daptomycin and quinupristin/dalfopristin. Resistance to tetracycline (16/21), clindamycin (15/21) and erythromycin (14/21) was the most common types of resistance in Group A animals. Three isolates also demonstrated resistance to rifampin. Resistance toward gentamicin (16/21), ciprofloxacin (15/21), macrolides (15/21) and tetracycline (12/21) was the most common in kennel dogs (Group B). The most common genes encoding resistance to antimicrobials (excluding beta-lactams) in isolates from Group A pets were tetK (21/42), aph(3′)-IIIa (11/42) and aac(6'')-Ie-aph(2'''')-Ia (9/42).

Conclusions

A wide range of MRS species were found in pet animals in Lithuania. MRSA was not found.  相似文献   

Phosphorus desorption and isotope exchange kinetics in agricultural soils     

Sabina Braun  Timothy I. McLaren  Emmanuel Frossard  J. R. Marius Tuyishime  Gunnar Börjesson  Jon Petter Gustafsson 《Soil Use and Management》2022,38(1):515-527

To improve phosphorus (P) fertilization and environmental assessments, a better understanding of release kinetics of solid-phase P to soil solution is needed. In this study, Fe (hydr)oxide-coated filter papers (Fh papers), isotopic exchange kinetics (IEK) and chemical extractions were used to assess the sizes of fast and slowly desorbing P pools in the soils of six long-term Swedish field experiments. The P desorption data from the Fh-paper extraction of soil (20 days of continual P removal) were fitted with the Lookman two-compartment desorption model, which estimates the pools of fast (Q₁) and slowly (Q₂) desorbing P, and their desorption rates k₁ and k₂. The amounts of isotope-exchangeable P (E) were calculated (E_1min to E_{>3 months}) and compared with Q₁ and Q₂. The strongest relationship was found between E_{1 min} and Q₁ (r² = .87, p < .01). There was also an inverse relationship between the IEK parameter n (the rate of exchange) and k₁ (r² = .52, p < .01) and k₂ (r² = .52, p < .01), suggesting that a soil with a high value of n desorbs less P per time unit. The relationships between these results show that they deliver similar information, but both methods are hard to implement in routine analysis. However, Olsen-extractable P was similar in magnitude to Q₁ (P-Olsen = 1.1 × Q₁ + 2.3, r² = .96), n and k₁ were related to P-Olsen/P-CaCl₂, while k₂ was related to P-oxalate/P-Olsen. Therefore, these extractions can be used to estimate the sizes and desorption rates of the different P pools, which could be important for assessments of plant availability and leaching.  相似文献   

Adhesive systems used in the European particleboard,MDF and OSB industries*     

George I. Mantanis  Eleftheria Th. Athanassiadou  Marius C. Barbu  Kris Wijnendaele 《Wood material science & engineering》2018,13(2):104-116

In this work, the adhesive systems used today in the European industries of particleboard, medium density fibreboard (MDF) and oriented strand board (OSB) are discussed. The structure of particleboard, MDF and OSB markets in Europe in relation to the types of adhesives and product specifications are presented as well. It is noticeable that new markets for wood-based panels like particleboard and fibreboard, known as non-furniture markets, are growing in Europe at a fast rate. It was concluded that most of the technological changes concerning the adhesive systems applied and additives have been realised from the need for niche panel products, the obligation to reach even lower formaldehyde emissions, and the necessity to decrease production costs due to the stringent competition in the market of wood-based panels.  相似文献   

Predicting dynamic modulus of elasticity of Norway spruce structural timber by forest inventory,airborne laser scanning and harvester-derived data     

Carolin Fischer  Olav A. Høibø  Geir I. Vestøl  Marius Hauglin  Endre H. Hansen  Terje Gobakken 《Scandinavian Journal of Forest Research》2018,33(6):603-612

Norway spruce structural timber is one of the most important products of the Norwegian sawmilling industry, and a high grade-yield of structural timber is therefore important for the economic yield. Presorting of logs suited for production of structural timber might be one option to increase the grade yield. In this study, dynamic modulus of elasticity (E_dyn) of structural timber was predicted based on forest inventory data at site level and single-tree data from airborne laser scanning (ALS) and harvester. The models were based on 611 boards from 4 sites in southeastern Norway. Important variables at site level were elevation, site index (SI), and mean stand age. However, when combining data from all information sources, mean stand age and site index were the only significant variables at site level. Tree height and variables describing the crown, like crown length and crown volume, were important vaiables extracted from ALS data. Stem diameter measures and tapering were important variables measured by the harvester. The combined model with variables from all three information sources reduced the variance the most, especially when using individual tree age instead of average stand age. However, combining all these data requires accurate positioning of the trees by the harvester.  相似文献   

Anthropogenic factors and the risk of highly pathogenic avian influenza H5N1: prospects from a spatial-based model     

Mathilde Paul  Saraya Tavornpanich  David Abrial  Patrick Gasqui  Myriam Charras-Garrido  Weerapong Thanapongtharm  Xiangming Xiao  Marius Gilbert  Francois Roger    Christian Ducrot 《Veterinary research》2010,41(3)

Beginning in 2003, highly pathogenic avian influenza (HPAI) H5N1 virus spread across Southeast Asia, causing unprecedented epidemics. Thailand was massively infected in 2004 and 2005 and continues today to experience sporadic outbreaks. While research findings suggest that the spread of HPAI H5N1 is influenced primarily by trade patterns, identifying the anthropogenic risk factors involved remains a challenge. In this study, we investigated which anthropogenic factors played a role in the risk of HPAI in Thailand using outbreak data from the “second wave” of the epidemic (3 July 2004 to 5 May 2005) in the country. We first performed a spatial analysis of the relative risk of HPAI H5N1 at the subdistrict level based on a hierarchical Bayesian model. We observed a strong spatial heterogeneity of the relative risk. We then tested a set of potential risk factors in a multivariable linear model. The results confirmed the role of free-grazing ducks and rice-cropping intensity but showed a weak association with fighting cock density. The results also revealed a set of anthropogenic factors significantly linked with the risk of HPAI. High risk was associated strongly with densely populated areas, short distances to a highway junction, and short distances to large cities. These findings highlight a new explanatory pattern for the risk of HPAI and indicate that, in addition to agro-environmental factors, anthropogenic factors play an important role in the spread of H5N1. To limit the spread of future outbreaks, efforts to control the movement of poultry products must be sustained.  相似文献   

Towards sustainable forest management in the European Union through polycentric forest governance and an integrated landscape approach     

Lazdinis  Marius  Angelstam  Per  Pülzl  Helga 《Landscape Ecology》2019,34(7):1737-1749

Context

Achieving sustainable development as an inclusive societal process, and securing sustainability and resilience of human societies as well as the natural environment are wicked problems. Realising sustainable forest management (SFM) policy in local landscapes is one example.

Objectives

Using the European Union as a case study for the implementation of SFM policy across multiple governance levels in different contexts, we discuss the benefits of adopting an integrated landscape approach with place and space, partnership and sustainability as three pillars.

Methods

We map the institutional frameworks for implementing SFM policy within all EU member states. Next, we analyse whether or not there is EU-level forest governance, and how power is distributed among EU, member state and operational levels.

Results

Mechanisms to steer a centralized forest governance approach towards SFM in the EU are marginal. Instead, there is a polycentric forest governance with 90 national and sub-national governments, which create and implement own and EU-wide SFM-related policies. Additionally, both among and within regional governance units there is a large variation in governance arrangements linked to land ownership at the operational level.

Conclusions

To effectively translate EU-wide SFM and SFM-related policies into action in local landscapes, it is crucial to acknowledge that there are different land ownership structures, landscape histories and alternative value chains based on multiple ecosystem services. Therefore regionally adapted landscape approaches engaging multiple stakeholders and actors through evidence-based landscape governance and stewardship towards sustainable forest landscape management are needed. Model Forest, Long-Term Socio-Ecological Research platform and Biosphere Reserve are three of many examples.

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Sensitivity of southern quebec lakes to acidic precipitation     

Marius Lachance  Bernard Bobée  Yves Grimard 《Water, air, and soil pollution》1985,25(2):115-132

Physico-chemical data from 258 Quebec lakes were collected during spring and summer 1980. These data are examined in order obtain a first general diagnosis of lake acidification in Quebec. The spatial variation of the mineralization of lakes is interpreted in relation to lithology and glacial deposits, allowing the identification of Shield areas particularly threatened by acid precipitation. A strong south-west to north-east gradient in sulphate concentration is observed and interpreted as a result of long range atmospheric transport of S and as an indication of increased sulphate levels in southern Quebec lakes. The frequency distribution of pH values and the relation between pH and sulphate are examined; the results obtained suggest that many Shield lakes are probably affected by acid precipitation. A comparison is made between spring and summer conditions; data obtained in spring show a substantial decrease in pH and alkalinity.  相似文献