Iron deficiency anemia is one of the most prevalent nutritional deficiency worldwide. The commonly used cut-off values for identifying iron deficiency are extrapolated from older children and may not be suitable for i...Iron deficiency anemia is one of the most prevalent nutritional deficiency worldwide. The commonly used cut-off values for identifying iron deficiency are extrapolated from older children and may not be suitable for infants. Therefore, our study aimed to establish appropriate cut-off values for the evaluation of iron status in Chinese infants. Pregnant women who delivered at 〉37 gestational weeks with normal iron status were recruited. Later, infants with normal birth weight and who were breastfed in the first 4 months were selected. Blood samples were collected to assess hemoglobin, serum ferritin, soluble transferrin receptor, mean corpuscular volume and free erythrocyte protoporphyrin. Cut-offs of all iron indices were determined as the limit of 95% confidence interval.展开更多
Humus forms, especially the occurrence and the thickness of the horizon of humified residues （OH）, provide valuable information on site conditions. In mountain forest soils, humus forms show a high spatial variabili...Humus forms, especially the occurrence and the thickness of the horizon of humified residues （OH）, provide valuable information on site conditions. In mountain forest soils, humus forms show a high spatial variability and data on their spatial patterns is often scarce. Our aim was to test the applicability of various vegetation features as proxy for OH thickness. Subalpine coniferous forests dominated by Picea abies （L.） H. Karst. and Larix decidua Mill. were studied in the Province of Trento, Italian Alps, between ca. 900 and 22o0 m a.s.1. Braun-Blanquet vegetation relevds and OH thickness were recorded at 152 plots. The vegetation parameters, tested for their suitability as indicators of OH thickness, encompassed mean Landolt indicator values of the herb layer （both unweighted and cover-weighted means） as well as parameters of vegetation structure （cover values of plant species groups） calculated from the releves. To our knowledge, the predictive power of Landolt indicator values （LIVs） for humus forms had not been tested before. Correlations between OHthickness and mean LIVs were strongest for the soil reaction value, but indicator values for humus, nutrients, temperature and light were also significantly correlated with OH thickness. Generally, weighting with species cover reduced the indicator quality of mean LIVs for OH thickness. The strongest relationships between OH thickness and vegetation structure existed in the following indicators： the cover of forbs （excluding graminoids and ferns） and the cover of Erieaeeae in the herb layer. Regression models predicting OH thickness based on vegetation structure had almost as much predictive power as models based on LIVs. We conclude that LIVs analysis can produce fairly reliable information regarding the thickness of the OH horizon and, thus, the humus form. If no releve data are readily available, a field estimation of the cover values of certain easily distinguishable herb layer species groups is much faster than a vegetation survey with consecutive indicator value analysis, and might be a feasible way of quickly indicating the humus form.展开更多
Background:The exclusion of tourist species from samples is important to avoid bias in community analyses.However,in practice,this is a very difficult task.The commonly used methods by researchers,when the habitat of ...Background:The exclusion of tourist species from samples is important to avoid bias in community analyses.However,in practice,this is a very difficult task.The commonly used methods by researchers,when the habitat of the species is not known,have several shortcomings:first,they exclude not only pseudo-rare species but also genuinely rare species;second,the results obtained with those methods depend on the abundance of the sampling;and third,they follow very subjective rules.The aims of this study were:(i)to propose a methodology to detect and exclude habitat-tourist species from the database used to carry out analyses in community ecology studies,(ii)to evaluate how the presence of habitat-tourist species affects the richness estimates,and(iii)to assess the effect of including juvenile spiders in the detection of tourist species and the effect of removing them from the richness estimates.Results:When the adult+juvenile dataset was considered,twenty-one habitat-tourist species were detected:8 in forest foliage,11 in forest leaf litter,and 2 in grassland.When habitat-tourist species were considered with this dataset,richness overestimation was significant in foliage and in leaf litter,and the final slopes of the richness estimation curves were significantly steeper in leaf litter.When only the adult dataset was considered,eight habitat-tourist species were detected:3 in forest foliage,4 in forest leaf litter,and just one in grassland.The inclusion of habitat-tourist species in this dataset showed an overestimation of richness,but this was not significant.Conclusions:The proposed methodology contributes to solving the problem of tourist species,which was recognized as one of the great problems in biodiversity studies.This study showed that common estimators overestimate species richness when habitat-tourist species are included,leading to erroneous conclusions.Besides,this research showed that the inclusion of juveniles(e.g.spiders)could improve the analysis outputs because it allowed the detection of more habitat-tourist species.展开更多
基金supported by Natural Science Foundation of China(Grant No.30972483)The Chinese clinical trial registry number is ChiCTR-TRC-12002838
文摘Iron deficiency anemia is one of the most prevalent nutritional deficiency worldwide. The commonly used cut-off values for identifying iron deficiency are extrapolated from older children and may not be suitable for infants. Therefore, our study aimed to establish appropriate cut-off values for the evaluation of iron status in Chinese infants. Pregnant women who delivered at 〉37 gestational weeks with normal iron status were recruited. Later, infants with normal birth weight and who were breastfed in the first 4 months were selected. Blood samples were collected to assess hemoglobin, serum ferritin, soluble transferrin receptor, mean corpuscular volume and free erythrocyte protoporphyrin. Cut-offs of all iron indices were determined as the limit of 95% confidence interval.
基金funded by the German Research Foundation(DFG)(Grant No.Br1106/23-1)the Swiss National Science Foundation(SNF)(Grant No.205321L_141186)the Austrian Science Fund(FWF)
文摘Humus forms, especially the occurrence and the thickness of the horizon of humified residues （OH）, provide valuable information on site conditions. In mountain forest soils, humus forms show a high spatial variability and data on their spatial patterns is often scarce. Our aim was to test the applicability of various vegetation features as proxy for OH thickness. Subalpine coniferous forests dominated by Picea abies （L.） H. Karst. and Larix decidua Mill. were studied in the Province of Trento, Italian Alps, between ca. 900 and 22o0 m a.s.1. Braun-Blanquet vegetation relevds and OH thickness were recorded at 152 plots. The vegetation parameters, tested for their suitability as indicators of OH thickness, encompassed mean Landolt indicator values of the herb layer （both unweighted and cover-weighted means） as well as parameters of vegetation structure （cover values of plant species groups） calculated from the releves. To our knowledge, the predictive power of Landolt indicator values （LIVs） for humus forms had not been tested before. Correlations between OHthickness and mean LIVs were strongest for the soil reaction value, but indicator values for humus, nutrients, temperature and light were also significantly correlated with OH thickness. Generally, weighting with species cover reduced the indicator quality of mean LIVs for OH thickness. The strongest relationships between OH thickness and vegetation structure existed in the following indicators： the cover of forbs （excluding graminoids and ferns） and the cover of Erieaeeae in the herb layer. Regression models predicting OH thickness based on vegetation structure had almost as much predictive power as models based on LIVs. We conclude that LIVs analysis can produce fairly reliable information regarding the thickness of the OH horizon and, thus, the humus form. If no releve data are readily available, a field estimation of the cover values of certain easily distinguishable herb layer species groups is much faster than a vegetation survey with consecutive indicator value analysis, and might be a feasible way of quickly indicating the humus form.
基金This research was financed by project PI F 003/2015 of the SGCyT-UNNE(Argentina)by a CONICET doctoral fellowship awarded to the first author.
文摘Background:The exclusion of tourist species from samples is important to avoid bias in community analyses.However,in practice,this is a very difficult task.The commonly used methods by researchers,when the habitat of the species is not known,have several shortcomings:first,they exclude not only pseudo-rare species but also genuinely rare species;second,the results obtained with those methods depend on the abundance of the sampling;and third,they follow very subjective rules.The aims of this study were:(i)to propose a methodology to detect and exclude habitat-tourist species from the database used to carry out analyses in community ecology studies,(ii)to evaluate how the presence of habitat-tourist species affects the richness estimates,and(iii)to assess the effect of including juvenile spiders in the detection of tourist species and the effect of removing them from the richness estimates.Results:When the adult+juvenile dataset was considered,twenty-one habitat-tourist species were detected:8 in forest foliage,11 in forest leaf litter,and 2 in grassland.When habitat-tourist species were considered with this dataset,richness overestimation was significant in foliage and in leaf litter,and the final slopes of the richness estimation curves were significantly steeper in leaf litter.When only the adult dataset was considered,eight habitat-tourist species were detected:3 in forest foliage,4 in forest leaf litter,and just one in grassland.The inclusion of habitat-tourist species in this dataset showed an overestimation of richness,but this was not significant.Conclusions:The proposed methodology contributes to solving the problem of tourist species,which was recognized as one of the great problems in biodiversity studies.This study showed that common estimators overestimate species richness when habitat-tourist species are included,leading to erroneous conclusions.Besides,this research showed that the inclusion of juveniles(e.g.spiders)could improve the analysis outputs because it allowed the detection of more habitat-tourist species.
