Authors:A. Sheikhi-Garjan, A. Hosseini-Gharalari, M. Mahjob, M. Rashid, Q. Sabahi, M. Safari, F. Jalilyan, and R. Arbabtafti
accuracy and spray coverage evaluation . Appl. Eng. Agric. , 10 , 463 – 470 .
Donskoff , M. ( 1996 ): Prospects for international cooperation of Sunn Pest research and control . FAO Plant Production and Protection Paper, Rome, Italy, No. , 138
Authors:G. Ónodi, Gy. Kröel-Dulay, E. Kovács-Láng, P. Ódor, Z. Botta-Dukat, B. Lhotsky, S. Barabás, J. Garadnai, and M. Kertész
Aboveground plant biomass is one of the most important features of ecosystems, and it is widely used in ecosystem research. Non-destructive biomass estimation methods provide an important toolkit, because the destructive harvesting method is in many cases not feasible. However, only few studies have compared the accuracy of these methods in grassland communities to date. We studied the accuracy of three widely used methods for estimation of aboveground biomass: the visual cover estimation method, the point intercept method, and field spectroscopy. We applied them in three independent series of field samplings in semi-arid sand grasslands in Central Hungary. For each sampling method, we applied linear regression to assess the strength of the relationship between biomass proxies and actual aboveground biomass, and used coefficient of determination to evaluate accuracy. We found no evidence that the visual cover estimation, which is generally considered as a subjective method, was less accurate than point intercept method or field spectroscopy in estimating biomass. Based on our three datasets, we found that accuracy was lower for the point intercept method compared to the other two methods, while field spectroscopy and visual cover estimation were similar to each other in the semi-arid sand grassland community. We conclude that visual cover estimation can be as accurate for estimating aboveground biomass as other approaches, thus the choice amongst the methods should be based on additional pros and cons associated with each of the method and related to the specific research objective.
Ad hoc decisions during fieldwork reduce the accuracy and reliability of vegetation maps. A method is proposed to objectify vegetation (thematic aspects) mapping (spatial aspects) for monitoring (temporal aspects). The most accurate and reliable description of the vegetation is a list of all plant species found within a plot. Therefore, the proposed method is an interpolation of a spatially representative sample of permanent plots combined with aerial photo interpretation. The method is objective because surveyors do not have to make decisions during fieldwork based on their personal judgement. Moreover, it is flexible, because the classification and interpolation methods can be adapted to specific views or needs depending on the aim of a study. The method was applied to an area in the north of the Netherlands in 1998. A sampling design with a density of 1 plot/ha was used, and interpolated with a perpendicular bisector. In 2002, the number of plots/ha was doubled. The influence of sample density on the mapping results was studied because it is an important decision to be made before fieldwork. Two plots/ha seem to be sufficient in order to obtain reliable information on patterns of plant species composition and vegetation types of the area, and their change over time. However, in patches where vegetation varies on a very small spatial scale this plot density was insufficient.
Different sampling strategies are simulated by changing quadrat size, quadrat shape, sample size and the arrangement of quadrats in a tropical rain forest of Hainan (South China). The simulation uses enumeration data of trees, and derived variables such as species richness, species importance, and species population density, to compare the efficiency of the sampling. The results verify that greater sampling efficiency is to be expected using systematic sampling than random sampling. Quadrat size has substantial influence on parameter estimation, but quadrat shape has negligible effect except when the quadrat is extremely long and narrow.
Authors:Pascal Meylan, Luc Paris, and Oliver Liesenfeld
, Thalib L , Tan HK , Paul M , Wallon M , et al. : Screening for congenital toxoplasmosis: accuracy of immunoglobulin M and immunoglobulin A tests after birth . J Med Screen 14 , 8 – 13 ( 2007
Authors:Ingrid E. Pereira, Kyssia P. Silva, Laura M. Menegati, Aimara C. Pinheiro, Elaine A. O. Assunção, Maria De Lourdes P. Araújo, Elfadil Abass, Malcolm S. Duthie, Ulrich Steinhoff, and Henrique C. Teixeira
accuracy of each antigen-specific ELISA, and association between assays were tested by Spearman coefficient correlation. Material and methods Serum samples A total of 88 dog serum samples were obtained from the Zoonosis Control Center serum repository
poor academic English are also considered as common reasons for direct rejection. English language polishing is a must to publish a scientific paper in a peer-reviewed scholarly journal [ 1, 2, 6, 13, 15 ]. Obviously, the accuracy and fluency of the