INTRODUCTION During the 1990s, the popularity of the genus Echinacea Moench (Asteraceae) as a dietary supplement in the United States increased markedly, as the general public learned of its possible efficacy in fighting colds and other illnesses (Bauer and Wagner 1991; Li 1998). Plant and medical scientists responded to this phenomenon by increasing their efforts to understand the biology, cul...

Although Chamaecrista Moench genus is a very important source of pollen to bees in the Cerrado, this relationship is almost unknown. Within flower visitors of Ch. debilis, we found hymenopterans (Apidae) as the most abundants, but Coleoptera (Buprestidae) and Lepidoptera (Noctuidae) were also collected. Bees of great size are pointed out as effective pollinators of Cassiinae. Only five out of s...

The aim of the present study was to investigate the effects of bee pollination of buckwheat crops on the seed productivity and plant development. Six plots each 4 m2 in size were arranged in a buckwheat field. Four plots in the field were isolated by a net. Nucs with bees were placed in two of the plots (one per plot). Plant productivity, height of plants and number of branches per marked plant...

Experimental evidence for the presence in mustard seedlings of an esterase that catalyzes the hydrolysis of sinapine into sinapic acid and choline has been presented previously (12). It was felt that further studies on this enzyme might be of some general biochemical interest. A preparation of sinapine esterase purified 20fold has been obtained from white mustard seedlings (Brassica hirta Moenc...

Infection with an endoparasite frequently alters host behaviour. This study provides the first quantification of larval behaviour in a baculovirus / Lepidoptera system, and attempts to assess the ecological consequences of behavioural modification during infection. Larvae of the moth Mamestra brassicae (Lepidoptera: Noctuidae) exhibited higher rates of dispersal in the laboratory and field when...

هدف: با توجه به رشد روزافزون آموزش شیوه مجازی و ویژه در شرایط گسترش پاندمی کرونایروس، نقش اساسی مدیریت کلاسی ارتقا کیفیت باید مورد قرار گیرد این پژوهش هدف تدوین مدل رابطه علّی هدفمند کلاس وضعیت روان‌شناختی پیامدهای تحصیلی دانشجویان انجام شد. روش: روش بر حسب هدف، کاربردی ماهیت از نوع توصیفی - همبستگی بود. جامعه آماری مشتمل انواع مقاطع دانشگاه­ های دولتی پیام نور شهر تهران نمونه اساس جدول مورگان ب...