Charcoal production in the Mopane woodlands of Mozambique: what are the trade-offs with other ecosystem services?

African woodlands form a major part of the tropical grassy biome and support the livelihoods of millions of rural and urban people. Charcoal production in particular is a major economic activity, but its impact on other ecosystem services is little studied. To address this, our study collected biophysical and social datasets, which were combined in ecological production functions, to assess ecosystem service provision and its change under different charcoal production scenarios in Gaza Province, southern Mozambique. We found that villages with longer histories of charcoal production had experienced declines in wood suitable for charcoal, firewood and construction, and tended to have lower perceived availabilities of these services. Scenarios of future charcoal impacts indicated that firewood and woody construction services were likely to trade-off with charcoal production. However, even under the most extreme charcoal scenario, these services were not completely lost. Other provisioning services, such as wild food, medicinal plants and grass, were largely unaffected by charcoal production. To reduce the future impacts of charcoal production, producers must avoid increased intensification of charcoal extraction by avoiding the expansion of species and sizes of trees used for charcoal production. This is a major challenge to land managers and policymakers in the area.This article is part of the themed issue ‘Tropical grassy biomes: linking ecology, human use and conservation’.     

Glucuronidation and sulfation of p-nitrophenol in isolated rat hepatocyte subpopulations. Effects of phenobarbital and 3-methylcholanthrene pretreatment

Parenchymal cells, isolated from untreated (control), phenobarbital(PB)-or 3-methylcholanthrene(3-MC)-treated rats, were separated into four subpopulations according to cell density, and glucuronidation and sulfation of p-nitrophenol (PNP) in the hepatocyte subpopulations were investigated. PB enhanced the glucuronidation almost 2-fold but not the sulfation, while 3-MC enhanced both glucuronidation (3-fold) and sulfation (2-fold) in the original cell suspensions. Some gradation trends were found in the conjugation activities among the hepatocyte subpopulations: In the control experiment, the extent of glucuronidation in four subpopulations was virtually the same but sulfation in high-density hepatocytes was slightly higher than in low-density ones. Both glucuronidation and sulfation were higher in low-density hepatocytes from PB-treated rats, though the gradation was very modest. Glucuronidation and sulfation tended to be slightly higher in middle-density hepatocytes in the 3-MC experiment. However, no definite correlation in conjugation activities vs. cell density, like those seen in cytochrome P-450s vs. cell density in the hepatocytes isolated from PB-treated rats, were found in the subpopulations from control or inducer-treated rats. Simultaneous studies on acetylation of p-aminobenzoic acid (PABA) revealed that the activities in the subpopulations were virtually the same and the inducers had little influence on the activity.     

Studies on the effect of protoplast density and genotype mixing on cell regeneration

Genotypes of Solanum tuberosum, assessed for their differential response to a protoplast regeneration protocol, were identified. This enabled comparisons to be made in relation to their abilities to regenerate into dividing cells and colonies. Protoplasts from genotypes with contrasting regeneration responses were plated as single or mixed genotype cultures at various plating densities in replicated, randomised experiments, and the effect on the regeneration of particular cell types observed. Protoplasts from single genotype cultures showed intergenotypic variation in the extent of cell regeneration and there were significant effects of genotype mixing and density × genotype mixing interactions. Overall, the effect of mixing was beneficial to a regenerating culture but significant density genotype mixing interactions showed only a positive benefit at the lowest plating density. The protoplast mixing phenomenon was not correlated with the behaviour of the same genotypes at the plantlet level in experiments with in vitro meristem cultures.     

Inferring functional relationships of proteins from local sequence and spatial surface patterns

We describe a novel approach for inferring functional relationship of proteins by detecting sequence and spatial patterns of protein surfaces. Well-formed concave surface regions in the form of pockets and voids are examined to identify similarity relationship that might be directly related to protein function. We first exhaustively identify and measure analytically all 910,379 surface pockets and interior voids on 12,177 protein structures from the Protein Data Bank. The similarity of patterns of residues forming pockets and voids are then assessed in sequence, in spatial arrangement, and in orientational arrangement. Statistical significance in the form of E and p-values is then estimated for each of the three types of similarity measurements. Our method is fully automated without human intervention and can be used without input of query patterns. It does not assume any prior knowledge of functional residues of a protein, and can detect similarity based on surface patterns small and large. It also tolerates, to some extent, conformational flexibility of functional sites. We show with examples that this method can detect functional relationship with specificity for members of the same protein family and superfamily, as well as remotely related functional surfaces from proteins of different fold structures. We envision that this method can be used for discovering novel functional relationship of protein surfaces, for functional annotation of protein structures with unknown biological roles, and for further inquiries on evolutionary origins of structural elements important for protein function.     

Analysis of Profiles Based on Ordinal Classification Functions and Rank Tests

In this article a test for the comparison of K groups of independent profiles is suggested. It is based on rank tests, in which the criterion is obtained by using a suitably chosen ordinal classification function. This function represents a specific view on the profiles. The test, which is easy to use, can be regarded as a generalisation of other well known tests and can be applied within a variety of situations. The relationships to other procedures for the analysis of profiles are described. Some properties are discussed.     

CO2浓度升高条件下长白赤松幼苗种植密度对净光合速率的影响

1　引　　言自 19世纪 70年代工业革命以来 ,由于人类活动的影响 ,大气ＣＯ2 浓度不断升高 ,已由工业革命前的 2 80 μｍｏｌ·ｍｏｌ-1增至目前的 35 0 μｍｏｌ·ｍｏｌ-1.据预测 ,到 2 0 5 0年将比工业革命前增加 1倍 ,到本世纪末将增加到 70 0 μｍｏｌ·ｍｏｌ-1左右[4 ,12 ,18] .大气ＣＯ2 浓度升高引起的温室效应对生物过程的影响 ,无疑是研究全球变化对陆地生态系统影响的基本问题 .目前 ,这方面的研究已成为国内外学者普遍关注的一个热点[2 ,3 ,5,6,9,17] .生态系统中的生物因子不是孤立存在的 ,每个有机体既处于无机环境之中 ,同…