227 research outputs found
Carbon implications of forest restitution in post-socialist Romania
The collapse of socialism in 1989 triggered a phase of institutional restructuring in Central and Eastern Europe. Several countries chose to privatize forests or to return them to pre-socialist owners. Here, we assess the implications of forest restitution on the terrestrial
The collapse of socialism in 1989 triggered a phase of institutional restructuring in Central and Eastern Europe. Several countries chose to privatize forests or to return them to pre-socialist owners. Here, we assess the implications of forest restitution on the terrestrial carbon balance. New forest owners have strong incentives to immediately clearcut their forests, resulting in increased terrestrial emissions. On the other hand, logging generally decreased after 1989 and forests are expanding on unused or abandoned farmland, both of which may offset increased logging on restituted forests. We mapped changes in forest cover for the entire country of Romania using Landsat satellite images from 1990 to 2010. We use our satellite estimates, together with historic data on logging rates and changes in forest cover, to parameterize a carbon book-keeping model for estimating the terrestrial carbon flux (above and below ground) as a consequence of land use change and forest harvest. High logging rates during socialism resulted in substantial terrestrial carbon emissions and Romania was a net carbon source until the 1980s. After the collapse of the Soviet Union forest harvest rates decreased dramatically, but since restitution laws were implemented they have increased by 60% (from 15 122 ± 5397 ha y − 1 in 2000 to 23 884 ± 11 510 ha y − 1 in 2010), but still remain lower than prior to 1989. Romania currently remains a terrestrial carbon sink, offsetting 7.6% ± 2.5% of anthropogenic carbon emissions. A further increase in logging could result in net emissions from terrestrial ecosystems during the coming decades. However, forest expansion on degraded land and abandoned farmland offers great potential for carbon sequestration.
decreased after 1989 and forests are expanding on unused or abandoned farmland, both of
which may offset increased logging on restituted forests. We mapped changes in forest cover
for the entire country of Romania using Landsat satellite images from 1990 to 2010. We use
our satellite estimates, together with historic data on logging rates and changes in
forest cover, to parameterize a carbon book-keeping model for estimating the
terrestrial carbon flux (above and below ground) as a consequence of land use change
and forest harvest. High logging rates during socialism resulted in substantial
terrestrial carbon emissions and Romania was a net carbon source until the 1980s.
After the collapse of the Soviet Union forest harvest rates decreased dramatically,
but since restitution laws were implemented they have increased by 60% (from
15 122 ± 5397 ha y − 1 in 2000 to
23 884 ± 11 510 ha y − 1 in 2010),
but still remain lower than prior to 1989. Romania currently remains a terrestrial carbon sink, offsetting
7.6% ± 2.5%
of anthropogenic carbon emissions. A further increase in logging could result in net
emissions from terrestrial ecosystems during the coming decades. However, forest
expansion on degraded land and abandoned farmland offers great potential for carbon
sequestration.Peer Reviewe
Serum steroid profiling by isotopic dilution-liquid chromatography-mass spectrometry: comparison with current immunoassays and reference intervals in healthy adults.
BACKGROUND:
The simultaneous, rapid and reliable measurement of a wide steroid panel is a powerful tool to unravel physiological and pathological hormone status. Clinical laboratories are currently dominated by high-throughput immunoassays, but these methods lack specificity due to cross-reactivity and matrix interferences. We developed and validated an isotopic dilution-liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) method for the simultaneous measurement of cortisol, corticosterone, 11deoxycortisol, androstenedione, deoxycorticosterone (DOC), testosterone, 17OHprogesterone, dehydroepiandrosterone (DHEA) and progesterone in serum, and compared it to routine immunoassays employed in our laboratory. We also established adult reference intervals in 416 healthy subjects.
METHODS:
0.9 ml of serum were spiked with labelled internal standards (IS) and extracted on C18 cartridges. Eluate was injected into a two-dimensional LC-system, purified in a perfusion column and separated on a C8 column during a 21 min gradient run. Analytes were revealed by atmospheric pressure chemical ionization (APCI) followed by multiple reaction monitoring (MRM) analysis.
RESULTS:
Of the four immunoassays compared with the ID-LC-MS/MS method, only the results of ElecsysE170 for cortisol, testosterone in males and progesterone>1 ng/ml were in agreement with ID-LC-MS/MS. ElecsysE170 for testosterone in females and progesterone<1 ng/ml, Immulite2000 for androstenedione, DSL-9000 for DHEA and 17OHP Bridge for 17OHprogesterone, respectively, showed poor agreement. Reference intervals and steroid age and fertility related fluctuations were established.
CONCLUSION:
Our ID-LC-MS/MS method proved to be reliable and sensitive in revealing steroid circulating concentrations in adults and in highlighting the limits of routine immunoassays at low concentrations
Characterizing degradation of palm swamp peatlands from space and on the ground: an exploratory study in the Peruvian Amazon
Peru has the fourth largest area of peatlands in the Tropics. Its most representative land cover on peat is a Mauritia flexuosa dominated palm swamp (thereafter called dense PS), which has been under human pressure over decades due to the high demand for the M. flexuosa fruit often collected by cutting down the entire palm. Degradation of these carbon dense forests can substantially affect emissions of greenhouse gases and contribute to climate change. The first objective of this research was to assess the impact of dense PS degradation on forest structure and biomass carbon stocks. The second one was to explore the potential of mapping the distribution of dense PS with different degradation levels using remote sensing data and methods. Biomass stocks were measured in 0.25 ha plots established in areas of dense PS with low (n = 2 plots), medium (n = 2) and high degradation (n = 4). We combined field and remote sensing data from the satellites Landsat TM and ALOS/PALSAR to discriminate between areas typifying dense PS with low, medium and high degradation and terra firme, restinga and mixed PS (not M. flexuosa dominated) forests. For this we used a Random Forest machine learning classification algorithm. Results suggest a shift in forest composition from palm to woody tree dominated forest following degradation. We also found that human intervention in dense PS translates into significant reductions in tree carbon stocks with initial (above and below-ground) biomass stocks (135.4 ± 4.8 Mg C ha−1) decreased by 11 and 17% following medium and high degradation. The remote sensing analysis indicates a high separability between dense PS with low degradation from all other categories. Dense PS with medium and high degradation were highly separable from most categories except for restinga forests and mixed PS. Results also showed that data from both active and passive remote sensing sensors are important for the mapping of dense PS degradation. Overall land cover classification accuracy was high (91%). Results from this pilot analysis are encouraging to further explore the use of remote sensing data and methods for monitoring dense PS degradation at broader scales in the Peruvian Amazon. Providing precise estimates on the spatial extent of dense PS degradation and on biomass and peat derived emissions is required for assessing national emissions from forest degradation in Peru and is essential for supporting initiatives aiming at reducing degradation activities
positive predictive value for malignancy on surgical excision of breast lesions of uncertain malignant potential b3 diagnosed by stereotactic vacuum assisted needle core biopsy vancb a large multi institutional study in italy
Abstract Percutaneous core biopsy (CB) has been introduced to increase the ability of accurately diagnosing breast malignancies without the need of resorting to surgery. Compared to conventional automated 14 gauge needle core biopsy (NCB), vacuum-assisted needle core biopsy (VANCB) allows obtaining larger specimens and has recognized advantages particularly when the radiological pattern is represented by microcalcifications. Regardless of technical improvements, a small percentage of percutaneous CBs performed to detect breast lesions are still classified, according to European and UK guidelines, in the borderline B3 category, including a group of heterogeneous lesions with uncertain malignant potential. We aimed to assess the prevalence and positive predictive values (PPV) on surgical excision (SE) of B3 category (overall and by sub-categories) in a large series of non-palpable breast lesions assessed through VANCB, also comparison with published data on CB. Overall, 26,165 consecutive stereotactic VANCB were identified in 22 Italian centres: 3107 (11.9%) were classified as B3, of which 1644 (54.2%) proceeded to SE to establish a definitive histological diagnosis of breast pathology. Due to a high proportion of microcalcifications as main radiological pattern, the overall PPV was 21.2% (range 10.6%–27.3% for different B3 subtypes), somewhat lower than the average value (24.5%) from published studies (range 9.9%–35.1%). Our study, to date the largest series of B3 with definitive histological assessment on SE, suggests that B3 lesions should be referred for SE even if VANCB is more accurate than NCB in the diagnostic process of non-palpable, sonographically invisible breast lesions
Projected heat-related mortality under climate change in the metropolitan area of Skopje
A Senescence-Like Cell-Cycle Arrest Occurs During Megakaryocytic Maturation: Implications for Physiological and Pathological Megakaryocytic Proliferation
During normal megakaryocyte development, in response to thrombopoetin, mature cells enter a senescence-like state in which they shed platelets; this state, characterized by cell cycle arrest, is defective in malignant megakaryocytes
Past and future carbon fluxes from land use change, shifting cultivation and wood harvest
Carbon emissions from anthropogenic land use (LU) and land use change (LUC) are quantified with a Dynamic Global Vegetation Model for the past and the 21st century following Representative Concentration Pathways (RCPs). Wood harvesting and parallel abandonment and expansion of agricultural land in areas of shifting cultivation are explicitly simulated (gross LUC) based on the Land Use Harmonization (LUH) dataset and a proposed alternative method that relies on minimum input data and generically accounts for gross LUC. Cumulative global LUC emissions are 72 GtC by 1850 and 243 GtC by 2004 and 27–151 GtC for the next 95 yr following the different RCP scenarios. The alternative method reproduces results based on LUH data with full transition information within <0.1 GtC/yr over the last decades and bears potential for applications in combination with other LU scenarios. In the last decade, shifting cultivation and wood harvest within remaining forests including slash each contributed 19% to the mean annual emissions of 1.2 GtC/yr. These factors, in combination with amplification effects under elevated CO2, contribute substantially to future emissions from LUC in all RCPs
Height-diameter allometry and above ground biomass in tropical montane forests: Insights from the Albertine Rift in Africa
Tropical montane forests provide an important natural laboratory to test ecological theory. While it is well-known that some aspects of forest structure change with altitude, little is known on the effects of altitude on above ground biomass (AGB), particularly with regard to changing height-diameter allometry. To address this we investigate (1) the effects of altitude on height-diameter allometry, (2) how different height-diameter allometric models affect above ground biomass estimates; and (3) how other forest structural, taxonomic and environmental attributes affect above ground biomass using 30 permanent sample plots (1-ha; all trees ≥ 10 cm diameter measured) established between 1250 and 2600 m asl in Kahuzi Biega National Park in eastern Democratic Republic of Congo. Forest structure and species composition differed with increasing altitude, with four forest types identified. Different height-diameter allometric models performed better with the different forest types, as trees got smaller with increasing altitude. Above ground biomass ranged from 168 to 290 Mg ha-1, but there were no significant differences in AGB between forests types, as tree size decreased but stem density increased with increasing altitude. Forest structure had greater effects on above ground biomass than forest diversity. Soil attributes (K and acidity, pH) also significantly affected above ground biomass. Results show how forest structural, taxonomic and environmental attributes affect above ground biomass in African tropical montane forests. They particularly highlight that the use of regional height-diameter models introduces significant biases in above ground biomass estimates, and that different height-diameter models might be preferred for different forest types, and these should be considered in future studies
Protecting 30% of the planet for nature: costs, benefits, and economic implications:Working paper analysing the economic implications of the proposed 30% target for areal protection in the draft post-2020 Global Biodiversity Framework
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