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This activity discusses a two-day unit on ecology implemented during the summer of 2004 using the project-based science instructional (PBSI) approach. Through collaborative fieldwork, group discussions, presentations, and reflections, students planned, implemented, and reported their own scientific investigations on the environmental health of their local park in the borough of Queens, New York City. Students' questions included a wide range of topics that dealt with plants, animals, soil and water, and the interactions and relationships between these variables. Findings from students' reports and presentations indicated that the pH of the soil and pond water system at the park, as well as the characteristics of terrestrial and aquatic organisms, differ by location. In addition, results of the unit of instruction demonstrated that it is possible to teach students science content and process in a reasonably short period using the PBSI approach.     

福建畲族人群体型特征

史料记载早在唐代以前畲族就居住在粤、闽、赣三省的交界处,现今畲族主要分布在福建、浙江、江西、广东、安徽、湖南、贵州等7个省份,但关于畲族的起源与迁移在学界一直存在较大争议。本研究在福建省福安市和福鼎市随机选取畲族年满18周岁的成人504人(其中男289人,女215人) 测量身高、体质量、肱骨内外上髁间径、股骨内外上髁间径、上臂紧张围、小腿围、肱三头肌皮褶、肩胛下皮褶、髂前上棘皮褶及小腿内侧皮褶等10 项体质指标,利用Heath-Carter 体型法分析福建东部畲族人群的体型,畲族男性平均体型（5.02-3.76-1.76）为偏中胚层的内胚层型,女性平均体型（6.91-3.50-1.23）为偏中胚层的内胚层型。将福建畲族三个因子值与其他少数民族及汉族进行比较,结果显示畲族体型与汉族群体更为接近,其中与闽南语族群汉族、闽东语族群汉族和广西汉族最为相近,与南方少数民族族群反而差异更大,提示在畲族的形成过程与汉族有着很大联系。本研究为畲族族源研究提供生物学方面的参考依据,也为我国人类学研究补充必要的数据和资料。     

Don't Fence Me In

There are many applications of applied psychophysiology. Some are relevant to AAPB's interests, some are not. However, in no case should we exclude them from our purview merely by defining them out of our existence.     

The plant genetic background affects the efficiency of the pepper major nematode resistance genes Me1 and Me3

Key message

The plant genetic background influences the efficiency of major resistance genes to root-knot nematodes in pepper and has to be considered in breeding strategies.

Abstract

Root-knot nematodes (RKNs), Meloidogyne spp., are extremely polyphagous plant parasites worldwide. Since the use of most chemical nematicides is being prohibited, genetic resistance is an efficient alternative way to protect crops against these pests. However, nematode populations proved able to breakdown plant resistance, and genetic resources in terms of resistance genes (R-genes) are limited. Sustainable management of these valuable resources is thus a key point of R-gene durability. In pepper, Me1 and Me3 are two dominant major R-genes, currently used in breeding programs to control M. arenaria, M. incognita and M. javanica, the three main RKN species. These two genes differ in the hypersensitive response induced by nematode infection. In this study, they were introgressed in either a susceptible or a partially resistant genetic background, in either homozygous or heterozygous allelic status. Challenging these genotypes with an avirulent M. incognita isolate demonstrated that (1) the efficiency of the R-genes in reducing the reproductive potential of RKNs is strongly affected by the plant genetic background, (2) the allelic status of the R-genes has no effect on nematode reproduction. These results highlight the primary importance of the choice of both the R-gene and the genetic background into which it is introgressed during the selection of new elite cultivars by plant breeders.