Effects of potassium and gibberellic acid on stem growth of whole sunflower plants

Abstract The effects of gibberellic acid (GA₃) on whole sunflower (Helianthus annuus L.) plants grown at three potassium (K) levels (0.0, 0.5 and 5.0 mM) were studied. A tenfold increase in the length of the first internode was observed when plants grown without K were treated with GA₃. The uneven K distribution along the plant (higher K content in the higher internodes) was enhanced by GA₃ treatment. Gibberellic acid increased the content of reducing sugars, especially in K-deficient plants. An increase in the K level in the nutrient solution resulted in a decrease of the osmotic potential of stem segments. Osmotic potential differences within the elongating first internode were increased by GA₃ treatment.     

A taxonomic revision of the Hilara maura-group (Diptera: Empididae) in Europe

Abstract. The European species of the Hilara maura-group are revised. Three species are described as new to science, namely, H.nitidorella sp.n., H.discalis sp.n. (both temperate Central and Western Europe) and H.mauroides sp.n. (Caucasus, male only). A further five species, H.hybrida Collin, H.femorella Zetterstedt, H.sulcitarsis Strobl, H.tyrolensis Strobl and H.bartaki Straka are redescribed, and H.eumera Loew, 1873 becomes a new synonym of H.nitidula Zetterstedt, 1838. Seven lectotypes are designated. All IS European species are keyed, the main differential characters are illustrated, and additional data on biology and distribution are given. The Hilara maura-group is recognized as a monophyletic group within the genus, characterized by a set of apomorphous characters, and the hypothetical phylogenetic relationships of the species, classified into four natural complexes, are demonstrated.     

Vestiges of an ancestral host plant: preference and performance in the butterfly Polygonia faunus and its sister species P. c‐album

1. In the study of the evolution of insect–host plant interactions, important information is provided by host ranking correspondences among female preference, offspring preference, and offspring performance. Here, we contrast such patterns in two polyphagous sister species in the butterfly family Nymphalidae, the Nearctic Polygonia faunus, and the Palearctic P. c‐album. 2. These two species have similar host ranges, but according to the literature P. faunus does not use the ancestral host plant clade – the ‘urticalean rosids’. Comparisons of the species can thus test the effects of a change in insect–plant associations over a long time scale. Cage experiments confirmed that P. faunus females avoid laying eggs on Urtica dioica (the preferred host of P. c‐album), instead preferring Salix, Betula, and Ribes. 3. However, newly hatched larvae of both species readily accept and grow well on U. dioica, supporting the general theory that evolutionary changes in host range are initiated through shifts in female host preferences, whereas larvae are more conservative and also can retain the capacity to perform well on ancestral hosts over long time spans. 4. Similar rankings of host plants among female preference, offspring preference, and offspring performance were observed in P. c‐album but not in P. faunus. This is probably a result of vestiges of larval adaptations to the lost ancestral host taxon in the latter species. 5. Female and larval preferences seem to be largely free to evolve independently, and consequently larval preferences warrant more attention.     

Allatostatin-like peptide in the brain-retrocerebral complex of the earwig Labidura riparia: cyclic variations related to the reproductive cycle

Summary

A polyclonal antibody raised against allatostatin-3 of Blattella germanica (BLAST-3) has been used to immunolocalize allatostatin-like peptides in the brain-retrocerebral complex of Labidura riparia adult females. Strongly stained immunoreactive cells are observed in the pars intercerebralis (14 cells) and mainly in the pars lateralis (32 cells). Fibres leading to the corpus allatum are also stained. In the deutocerebrum, one cell is immunostained at the root of each antennal nerve. In the tritocerebmm two cells in each brain hemisphere are weakly immunostained. During the reproductive cycle, these cells and their axons show immunoreactivity at previtellogenic, ovulation and ovarian arrest periods. During vitellogenesis, immunoreactivity is restricted to only four perikarya in the pars intercerebralis.

When young vitellogenic females are injected with 20-hydroxyecdysone (20E), which inhibits vitellogenesis, full immunoreactivity reappears, suggesting sensibility of these cells to 20E as is expected for a negative feed-back loop (Sayah et al., 1995).

These results show that BLAST-3-like material is produced periodically in Labidura in correlation with low levels of juvenile hormone and the absence of vitellogenesis. This study contributes to provide information on the degree of homology of allatostatins across various insects.     

Barriers and facilitators to implement shared decision making in multidisciplinary sciatica care: a qualitative study

Background

Venous thromboembolism (VTE) is a common preventable cause of mortality in hospitalized medical patients. Despite rigorous randomized trials generating strong recommendations for anticoagulant use to prevent VTE, nearly 40% of medical patients receive inappropriate thromboprophylaxis. Knowledge-translation strategies are needed to bridge this gap.

Methods

We conducted a 16-week pilot cluster randomized controlled trial (RCT) to determine the proportion of medical patients that were appropriately managed for thromboprophylaxis (according to the American College of Chest Physician guidelines) within 24 hours of admission, through the use of a multicomponent knowledge-translation intervention. Our primary goal was to determine the feasibility of conducting this study on a larger scale. The intervention comprised clinician education, a paper-based VTE risk assessment algorithm, printed physicians’ orders, and audit and feedback sessions. Medical wards at six hospitals (representing clusters) in Ontario, Canada were included; three were randomized to the multicomponent intervention and three to usual care (i.e., no active strategies for thromboprophylaxis in place). Blinding was not used.

Results

A total of 2,611 patients (1,154 in the intervention and 1,457 in the control group) were eligible and included in the analysis. This multicomponent intervention did not lead to a significant difference in appropriate VTE prophylaxis rates between intervention and control hospitals (appropriate management rate odds ratio = 0.80; 95% confidence interval: 0.50, 1.28; p = 0.36; intra-class correlation coefficient: 0.022), and thus was not considered feasible. Major barriers to effective knowledge translation were poor attendance by clinical staff at education and feedback sessions, difficulty locating preprinted orders, and lack of involvement by clinical and administrative leaders. We identified several factors that may increase uptake of a VTE prophylaxis strategy, including local champions, support from clinical and administrative leaders, mandatory use, and a simple, clinically relevant risk assessment tool.

Conclusions

Hospitals allocated to our multicomponent intervention did not have a higher rate of medical inpatients appropriately managed for thromboprophylaxis than did hospitals that were not allocated to this strategy.     

Expression and regulation of neurotrophic and angiogenic factors during human intervertebral disc degeneration

Introduction

The degenerate intervertebral disc (IVD) becomes innervated by sensory nerve fibres, and vascularised by blood vessels. This study aimed to identify neurotrophins, neuropeptides and angiogenic factors within native IVD tissue and to further investigate whether pro-inflammatory cytokines are involved in the regulation of expression levels within nucleus pulposus (NP) cells, nerve and endothelial cells.

Methods

Quantitative real-time PCR (qRT-PCR) was performed on 53 human IVDs from 52 individuals to investigate native gene expression of neurotrophic factors and their receptors, neuropeptides and angiogenic factors. The regulation of these factors by cytokines was investigated in NP cells in alginate culture, and nerve and endothelial cells in monolayer using RT-PCR and substance P (SP) protein expression in interleukin-1 (IL-1β) stimulated NP cells.

Results

Initial investigation on uncultured NP cells identified expression of all neurotrophins by native NP cells, whilst the nerve growth factor (NGF) receptor was only identified in severely degenerate and infiltrated discs, and brain derived neurotrophic factor (BDNF) receptor expressed by more degenerate discs. BDNF expression was significantly increased in infiltrated and degenerate samples. SP and vascular endothelial growth factor (VEGF) were higher in infiltrated samples. In vitro stimulation by IL-1β induced NGF in NP cells. Neurotropin-3 was induced by tumour necrosis factor alpha in human dermal microvascular endothelial cells (HDMECs). SP gene and protein expression was increased in NP cells by IL-1β. Calcitonin gene related peptide was increased in SH-SY5Y cells upon cytokine stimulation. VEGF was induced by IL-1β and interleukin-6 in NP cells, whilst pleiotrophin was decreased by IL-1β. VEGF and pleiotrophin were expressed by SH-SY5Y cells, and VEGF by HDMECs, but were not modulated by cytokines.

Conclusions

The release of cytokines, in particular IL-1β during IVD degeneration, induced significant increases in NGF and VEGF which could promote neuronal and vascular ingrowth. SP which is released into the matrix could potentially up regulate the production of matrix degrading enzymes and also sensitise nerves, resulting in nociceptive transmission and chronic low back pain. This suggests that IL-1β is a key regulatory cytokine, involved in the up regulation of factors involved in innervation and vascularisation of tissues.     

燕麦EST-SSR标记的开发和利用

为拓展分子标记在燕麦种质资源分析与鉴定中的应用,利用公共数据库中的25376条EST(expressed sequence tags)序列,开展了燕麦EST-SSR功能性标记的开发和利用研究。25376条EST序列经拼接去冗余后获得了11618条序列,从中筛选出含有不同重复基元的SSR且重复次数较多、长度较长的556条EST序列进行引物设计,开发了50对燕麦EST-SSR引物,通过筛选得到40对有效的EST-SSR引物。选取其中4对引物对5个燕麦种质资源进行了PCR扩增及产物测序,结果表明扩增条带多态性是由SSR差异造成的。利用40对ESTSSR引物对15个六倍体燕麦种质资源进行遗传多样性分析,共扩增出89个等位基因,平均每对引物产生2.23个等位基因;UPGMA聚类分析表明,15个六倍体燕麦种质资源在Dice系数为0.93处聚为3支,基本上是按照不同种进行聚类的,在相同种中又根据地理来源分别聚集成支。利用40对EST-SSR引物对31个遗传背景不清的燕麦种质资源进行基因组倍性鉴定,发现这些种质中可能存在有四倍体和二倍体的燕麦新资源。本研究开发的燕麦EST-SSR功能性标记将在燕麦遗传多样性分析、遗传图谱构建及燕麦属内种间基因组鉴定等方面发挥重要作用。     

藏南布丹拉山南坡种子植物区系海拔格局分析

生态群落交错区通常因物种丰富、区系成分复杂而被视为关键带.藏南布丹拉山处在半湿润向半干旱的生态环境过渡带上,因其特殊的自然地理环境而有着丰富的山地植物多样性,但这一重要生态过渡区的种子植物组成和区系成分海拔分布格局目前尚缺乏了解.为了理清布丹拉山南坡种子植物区系成分及其垂直分布变化格局,该文通过野外植物群落的样方调查、...     

Systematics of Oreobates and the Eleutherodactylus discoidalis species group (Amphibia, Anura), based on two mitochondrial DNA genes and external morphology

We present morphological and molecular (mitochondrial DNA, mtDNA) evidence supporting the validity and monophyly of the genus Oreobates . This genus also includes members of the former Eleutherodactylus discoidalis species group plus Eleutherodactylus heterodactylus . The presence of prominent conical subarticular tubercles and prominent supernumerary tubercles associated with the axis of fingers and toes, the presence of glandular axillary pads, and the absence of vocal sacs are proposed as morphological synapomorphies. Species of this taxon form a well-supported crown clade in a phylogeny including members of the genera Craugastor and Eleutherodactylus s.l. The sister taxon to Oreobates is the Eleutherodactylus martinicensis series; Oreobates does not appear to be closely related to the Eleutherodactylus binotatus series or to members of the Eleutherodactylus dolops and Eleutherodactylus nigrovittatus species groups. The taxonomic status of all species of Oreobates is reassessed. Hylodes philippi and Hylodes verrucosus are removed from the synonymy of Oreobates quixensis . We redescribe Oreobates cruralis on the basis of the holotype and new material from Bolivia and Peru, and restrict its distribution to the humid forests of the lowlands and adjacent foothills of the Andes, from southern Peru to central Bolivia. Oreobates granulosus is rediscovered, redescribed, and resurrected, on the basis of the examination of the holotype and additional material from Peru. Phylogenetic analyses of partial 16S mtDNA are used to test the independence of lineages (species). The 14 species of Oreobates are distributed from southern Ecuador to northern Argentina. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 737–773.