Publications by authors named "M Elske van den Akker-van Marle"

6 Publications

  • Page 1 of 1

Fire and deforestation dynamics in Amazonia (1973-2014).

Global Biogeochem Cycles 2017 01 12;31(1):24-38. Epub 2017 Jan 12.

NASA Goddard Institute for Space Studies New York New York USA; Center for Climate Systems Research Columbia University New York New York USA.

Consistent long-term estimates of fire emissions are important to understand the changing role of fire in the global carbon cycle and to assess the relative importance of humans and climate in shaping fire regimes. However, there is limited information on fire emissions from before the satellite era. We show that in the Amazon region, including the Arc of Deforestation and Bolivia, visibility observations derived from weather stations could explain 61% of the variability in satellite-based estimates of bottom-up fire emissions since 1997 and 42% of the variability in satellite-based estimates of total column carbon monoxide concentrations since 2001. This enabled us to reconstruct the fire history of this region since 1973 when visibility information became available. Our estimates indicate that until 1987 relatively few fires occurred in this region and that fire emissions increased rapidly over the 1990s. We found that this pattern agreed reasonably well with forest loss data sets, indicating that although natural fires may occur here, deforestation and degradation were the main cause of fires. Compared to fire emissions estimates based on Food and Agricultural Organization's Global Forest and Resources Assessment data, our estimates were substantially lower up to the 1990s, after which they were more in line. These visibility-based fire emissions data set can help constrain dynamic global vegetation models and atmospheric models with a better representation of the complex fire regime in this region.
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http://dx.doi.org/10.1002/2016GB005445DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5324547PMC
January 2017

Selection of polymorphic peptides from GRA6 and GRA7 sequences of Toxoplasma gondii strains to be used in serotyping.

Clin Vaccine Immunol 2009 Aug 3;16(8):1158-69. Epub 2009 Jun 3.

Center for Parasite Immunology and Biology, INSA, Porto, Portugal.

The evaluation of Toxoplasma gondii isolates obtained from geographical environments other than Europe and North America revealed the existence of atypical strains that are not included in the three archetypal clonal lineages (lineages I, II, and III). GRA6 and GRA7 are polymorphic genes that have been used for the genotyping of Toxoplasma. The coding regions of GRA6 and GRA7 from 49 nonarchetypal strains were sequenced and compared with the sequences of type I, II, and III reference strains. Eighteen and 10 different amino acid sequences were found for GRA6 and GRA7, respectively. The polymorphisms found between the different sequences were analyzed, with the objective of defining peptides to be used for the serotyping of Toxoplasma infections. Two peptides specific for clonal lineages I and III (peptides GRA7I and GRA7III, respectively) were selected from the GRA7 locus. Three peptides specific for some atypical strains (peptides Am6, Af6, and Am7) were selected from both the GRA6 and the GRA7 loci. Serum samples from humans infected with Toxoplasma strains of known genotypes were serotyped with the selected peptides. Peptide GRA7III seems to be a good candidate for the serotyping of infections caused by type III strains. Peptide GRA7I had a very low sensitivity. Peptides Am6 and Af6 had low specificities, since they reacted with serum samples from patients infected with strains belonging to the three archetypal lineages. Although peptide Am7 was specific, it had low sensitivity.
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http://dx.doi.org/10.1128/CVI.00092-09DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2725539PMC
August 2009

Toxoplasma strain type and human disease: risk of bias during parasite isolation?

Trends Parasitol 2004 Apr;20(4):160-2; discussion 162-3

Department of Parasitology, EA 2070, IFR53, UFR Médecine, Hôpital Maison-Blanche, 45 Rue Cognacq-Jay, 51092 Reims Cedex, France.

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http://dx.doi.org/10.1016/j.pt.2004.01.009DOI Listing
April 2004

Left ventricular mass in dippers and nondippers with newly diagnosed hypertension.

Angiology 2003 Nov-Dec;54(6):661-9

Department of Geriatrics, Ist Institute of Medicine, La Sapienza University, Rome, Italy.

Hypertensive subjects can be subdivided into 2 groups, dippers and nondippers, according to the presence or the lack of a nocturnal fall of blood pressure of more than 10%. Several studies have investigated cardiac organ damage in the 2 groups with discordant results, but they included subjects with different onset, severity, and treatment of hypertension. The authors selected 23 dippers and 17 nondippers affected by newly (< 1 year) diagnosed grades 1 and 2 hypertension, never treated, who underwent 24-hour ambulatory blood pressure monitoring and M-mode echocardiography. They did not find significant differences between the 2 groups as regards the echocardiographic left ventricular and atrial dimensions or regarding the left ventricular mass, left ventricular mass index, or relative wall thickness. Also no significant differences were found in the rate of either left ventricular remodeling or left ventricular hypertrophy. These data suggest that nondipping status is not associated with a higher level of cardiac involvement in the early phases of hypertension compared to dipping status.
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http://dx.doi.org/10.1177/000331970305400605DOI Listing
January 2004

Non-progression of cervical intraepithelial neoplasia estimated from population-screening data.

Br J Cancer 1997 ;75(1):124-30

Department of Public Health, Faculty of Medicine, Erasmus University Rotterdam, The Netherlands.

Non-progression and duration of preclinical neoplastic lesions of the cervix uteri were studied using screening data from a previously unscreened population, Maribo County, Denmark (1966-82). To estimate regression rates, the incidence of clinical cancer before the screening programme was related to the prevalence and incidence of preclinical lesions estimated from the detection rates of first smear and third and subsequent smears respectively. Duration was estimated from the time lag between the cumulative incidence of preclinical lesions and the combined cumulative incidence of clinical cancer and the estimated 'incidence of regression'. Of all preclinical lesions in women aged 25-50, 24% progressed, 39% regressed and 38% remained. Even if we assume no onset of preclinical lesions above age 50, we estimated that 48% of the preclinical lesions would not progress to clinical cancer in the women's lifetime. The estimated mean duration of preclinical lesions was 16 years. In Maribo County during the 1970s, the positive rate (1.6%) was low compared with current rates in several countries. We conclude that the detection of non-progressive lesions was outweighed by the prevention of clinical cancer.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2222698PMC
http://dx.doi.org/10.1038/bjc.1997.20DOI Listing
February 1997

Gelation of proteins from milk.

Faraday Discuss 1995 (101):185-200

NIZO, Netherlands Institute for Dairy Research, Ede, The Netherlands.

We give a quantitative treatment of the destabilization of three types of milk protein dispersions. For this we consider the proteins as adhesive-hard-sphere bio-colloids. If the attractive interactions become strong enough the system passes the percolation threshold and gels. Macroscopic properties of these gels are studied by measuring viscoelasticity and permeability coefficients. These coefficients are related to structural (fractal) properties of the gels which were measured using scattering and confocal scanning laser microscopy (CLSM) techniques. The behaviour of the protein gels can be understood on a qualitative level.
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http://dx.doi.org/10.1039/fd9950100185DOI Listing
November 1996