Identification of four distinct ‘Candidatus Phytoplasma’ species in pomegranate trees showing witches' broom,little leaf and yellowing in Jordan,and preliminary insights on their putative insect vectors and reservoir plants

During field surveys conducted in northern Jordan from June to November 2020, phytoplasma-like symptoms, including leaf yellowing/reddening and rolling, little leaf and witches' broom were observed in pomegranate. Disease incidence in 22 surveyed orchards ranged from 30% to 65%. Nested PCR-based amplification of 16S rRNA gene detected phytoplasmas in 17% of collected symptomatic pomegranate trees. Amplicon nucleotide sequence analyses allowed attributing the detected phytoplasmas to ‘Candidatus Phytoplasma solani’, ‘Ca. P. aurantifolia’, ‘Ca. P. asteris’ and ‘Ca. P. ulmi’. These phytoplasmas were found in plants showing specific symptoms and differentially distributed in the considered locations. Additionally, three cicadellids (Macrosteles sexnotatus, Cicadulina bipunctata and Psammotettix striatus) and two non-crop plants (Plantago major and Capsicum annuum) resulted hosting ‘Ca. P. asteris’ strains, and one cicadellid (Balclutha incisa) was carrying a ‘Ca. P. solani’ strain. A new pomegranate disease complex associated with multiple phytoplasmas, including ‘Ca. P. aurantifolia’ and ‘Ca. P. ulmi’, never reported before in this host plant, is described here. Moreover, preliminary indications are provided on its possible epidemiology in Jordan, involving two putative insect vectors (M. sexnotatus, B. incisa) first reported in the Country.     

New racisms,new racial subjects? The neo-liberal moment and the racial landscape of contemporary Britain

Abstract

The articles in this volume reflect upon a very specific moment in the social architecture of British society: a moment that brings financial meltdown together with some sizeable shifts in the racial and ethnic landscape of the UK. As a ‘neo-liberal revolution’ heralds the end of public services and the end of the welfare state, it proclaims ‘the end of race’ as well. But cultural retrenchment and coded xenophobia have also been sweeping the political terrain, accompanied by ‘new racisms’ and ‘new racial subjects’ that only close contextual analysis can unpick. Against those who suggest that we live in a post-racial time, the research presented offers friction. By focusing on particular locations in Britain at a particular moment, the articles explore local stories of ‘race’ and racism across changing sociopolitical ground.     

The Problem Realm and the World of Inner Experiences of Upper-Grade Students

In her chapter, the author understands ‘problems’ not as problems of solving learning tasks, but life situations which a young person has to solve. Such situations are often negative experiences. The author claims that problem situations can only be evaluated on the basis of ‘perezhivanie’ associated with them. This aspect is seldom present in psychological-pedagogical research. Most research starting from the 1920’s uses personal diaries or observations as the methods of studying life problems. But they are not able to reveal objectively relations between life problems and their ‘perezhivanie.’ The author introduces two new survey methods called “the world of perezhivanie” and “panorama of problems,” with which primary material is collected for further elaboration of the relation between problem domains and ‘perezhivanie.’ The chapter presents new methods of collecting data. Empirical results are published in other journals and books.     

Genetic sex determination,sex chromosome size and sex-specific lifespans across tetrapods

Sex differences in lifespan are ubiquitous across the tree of life and exhibit broad taxonomic patterns that remain a puzzle, such as males living longer than females in birds and vice versa in mammals. The prevailing unguarded X hypothesis explains sex differences in lifespan by differential expression of recessive mutations on the X or Z chromosome of the heterogametic sex, but has only received indirect support to date. An alternative hypothesis is that the accumulation of deleterious mutations and repetitive elements on the Y or W chromosome might lower the survival of the heterogametic sex (‘toxic Y’ hypothesis). Here, we use a new database to report lower survival of the heterogametic relative to the homogametic sex across 136 species of birds, mammals, reptiles and amphibians, as expected if sex chromosomes shape sex-specific lifespans, and consistent with previous findings. We also found that the relative sizes of both the X and the Y chromosomes in mammals (but not the Z or the W chromosomes in birds) are associated with sex differences in lifespan, as predicted by the unguarded X and the ‘toxic Y’. Furthermore, we report that the relative size of the Y is negatively associated with male lifespan in mammals, so that small Y size correlates with increased male lifespan. In theory, toxic Y effects are expected to be particularly strong in mammals, and we did not find similar effects in birds. Our results confirm the role of sex chromosomes in explaining sex differences in lifespan across tetrapods and further suggest that, at least in mammals, ‘toxic Y’ effects may play an important part in this role.     

锦带花属2个新品种

描述了2个锦带花属新品种,即贵妃锦带（Weigela florida ‘Royal’）和宝石锦带(Weigela florida‘Ruby’)。二者相近似,区别在于贵妃锦带植株稍高,株高1.5～2.0 m,花为尖晶玉红色,叶色暗绿;宝石锦带植株较矮,株高1.0～1.6 m,花为丹紫红色,叶片金黄色。这2个新品种均具有观赏特异性,抗逆性强,花期早且长等特性。     

Reduction of oxygen-pulsed cytochrome c oxidase by cytochrome c and other electron donors

1. Stopped-flow experiments were performed in which solutions containing dithionite were mixed with air-saturated buffer. Cytochrome c oxidase present in the dithionite-containing syringe is fully oxidized within the mixing time and the oxygen-pulsed form of the oxidase is produced.2. The reduction of this form by dithionite, by dithionite plus cytochrome c and by dithionite plus methyl viologen or benzyl viologen was followed and compared with the corresponding reduction reactions of the ‘resting’ oxidized enzyme. Reduction by dithionite is relatively slow, but the rate of reduction is greatly increased by addition of cytochrome c or the viologens, which are even more effective than cytochrome c on a molar basis.3. Profound differences between the transient kinetics of the reduction of the two oxidized oxidase derivatives were observed. The results are consistent with a direct reduction of cytochrome a followed by an intramolecular electron transfer to cytochrome a₃ (k^obs₁ = 7.5 s^?1 for the oxygen-pulsed oxidase).4. The spectrum of the oxygen-pulsed oxidase formed within 5 ms of the mixing closely resembles that of the ‘oxygenated’ compound, but there were small differences between the two spectra.     

基于“源-汇”理论的流域非点源污染控制景观格局调控框架——以厦门市马銮湾流域为例

基于“源-汇”理论对景观格局进行调控与优化是一种较为经济、有效的流域非点源污染控制新方法,目前尚处在探索阶段.在景观生态学及相关理论与前人已有研究的基础上,以流域整体为对象,从2个层次构建基于“源-汇”理论的流域非点源污染控制景观格局调控框架: 1)流域层次:在分析流域“源-汇”景观合理的基本组合与空间布局方式的基础上,建立了流域景观格局整体调控与优化方法;2)景观斑块类型层次:将关键“源”景观作为重点调控与优化对象,建立了包含景观单位面积污染负荷、景观坡度、起传输作用的狭长“源”景观、临河“源”景观单位岸线长度污染负荷等4项关键“源”景观识别准则,并遵循镶嵌“汇”景观、局部增补带型“汇”景观、提高原有“汇”景观消纳污染物的能力等3项调控与优化原则,针对农村地区与城区不同的关键“源”景观类型,制定了9类调控与优化方法.最后将该框架应用到厦门市马銮湾流域,基于GIS平台及研究区遥感图像与数字高程模型,制定了马銮湾流域景观格局整体调控与优化模式及3个片区关键“源”景观调控与优化方案.     

马鞍列岛海域蟹类群落结构及其多样性

基于2013年7月(夏季)、10月(秋季)、2014年3月(冬季)和5月(春季)在马鞍列岛海域桁杆虾拖网的采样数据,分析了蟹类种类组成、优势种及多样性等群落结构特征,并结合水深、底层温度和底层盐度等环境因子进行了探讨。结果表明:在研究海域共采获蟹类22种,隶属于11科15属;夏季种类数(20种)秋季(16种)春季(9种)冬季(8种);日本蟳(Charybdis japonica)和双斑蟳(Charybdis bimaculata)为蟹类群落优势种,三疣梭子蟹(Portunus trituberculatus)为夏秋季蟹类群落次优势种;丰富度指数(D)变化范围为0.43~1.01,多样性指数(H)变化范围为0.34~0.94,二者均值在秋季最高,冬季最低;均匀度指数(J)则为春季(0.70)冬季秋季夏季(0.35);底层温度是影响蟹类群落组成的最重要因子;聚类和非度量多维标度分析结果表明,各季节蟹类群落结构差异不显著,群落结构相对稳定。     

Ethnicity and naturalization

This article examines whether or not ethnicity has an independent effect on the likelihood of immigrant naturalization using the Public Use Microdata Sample [PUMS] data from the 1980 US Census. Ethnic differences in the propensity to become naturalized US citizens were analysed among four panethnic groups and across thirty‐three major ethnic groups. The results point to the continuing significance of ethnicity in the naturalization process. However, the effect of ethnicity is not as strong as the effects of other structural factors. Three hypotheses that attempt to explain ethnic differences in the propensity for naturalization were also tested. The evidence lends strong support to the forced self‐protection hypothesis, but it provides no support for the discrimination hypothesis and the cultural differences hypothesis.     

Fluid and cation secretion by the Malpighian tubules of Locusta

In vitro preparations of Locusta Malpighian tubules are able to transport K⁺ against its concentration gradient. The ‘urine’ is slightly hyper-osmotic with respect to the bathing solution and the rate of secretion is inversely dependent on the osmotic pressure of the latter. The rate of fluid secretion increases with increasing temperature; being maximal at approx 40°C. The ionic composition of the secreted fluid, as indicated by Na⁺/K⁺ ratios, is altered by the presence of 1 mM ouabain in the bathing solution. Fluid secretion is inhibited by 1 mM ouabain. In addition, oxygen consumption by the Malpighian tubules is inhibited by either the presence of 1 mM ouabain or the absence of K⁺ in the bathing solution. The relationship between respiration, active transport and the Na⁺K⁺-activated ATPase is discussed.     

Both black and symbolically white: The ‘Bajan-Brit’ return migrant as post-colonial hybrid

The research presented in this article centres on an under-researched demographic group of young return migrants, namely, second-generation Barbadians, or ‘Bajan-Brits’, who have decided to ‘return’ to the birthplace of their parents. Based on 51 in-depth interviews, the essay examines the experiences of second-generation return migrants from an interpretative perspective framed within post-colonial discourse. The article first considers the Bajan-Brits and issues of race in the UK before their decision to migrate. It is then demonstrated that on ‘return’, in certain respects, these young, black English migrants occupy a liminal position of cultural, racial and economic privilege, based on their ‘symbolic’ or ‘token’ whiteness within the post-colonial context of Barbados. But this very hybridity and inbetweeness means that they also face difficulties and associated feelings of social alienation and discrimination. The ambivalent status of this transnational group of migrants serves to challenge traditional notions of Barbadian racial identity.     

Volatile flavour components of cashew ‘apple’ (Anacardium occidentale)

An essence of fresh cashew ‘apple’, obtained by well-established procedures and possessing the characteristic aroma of that fruit, was analysed by GC and by GC/MS using both EI and CI techniques. The fruit produced a very small quantity of aroma volatiles (ca 3.6 μ/kg fresh fruit), much less than that obtained from most similar tropical fruits. Five aldehydes comprised ca 26% of the sample, but terpene hydrocarbons (ca 38%) provided the major group of compounds, consisting of four monoterpenes (ca 34%) and three sesquiterpenes (ca 4%). Important constituents of the essence included hexanal, car-3-ene, limonene, trans-hex-2-enal and benzaldehyde. Car-3-ene (24.3%) was the major constituent, and it was observed that during some recent analyses of tropical fruits this relatively uncommon aroma volatile had been identified in three out of four fruits studied of Venezuelan origin.     

The integration of 'omic' disciplines and systems biology in cattle breeding

Enormous progress has been made in the selection of animals, including cattle, for specific traits using traditional quantitative genetics approaches. Nevertheless, considerable variation in phenotypes remains unexplained, and therefore represents potential additional gain for animal production. In addition, the paradigm shift in new disciplines now being applied to animal breeding represents a powerful opportunity to prise open the 'black box' underlying the response to selection and fully understand the genetic architecture controlling the traits of interest. A move away from traditional approaches of animal breeding toward systems approaches using integrative analysis of data from the 'omic' disciplines represents a multitude of exciting opportunities for animal breeding going forward as well as providing alternatives for overcoming some of the limitations of traditional approaches such as the expressed phenotype being an imperfect predictor of the individual's true genetic merit, or the phenotype being only expressed in one gender or late in the lifetime of an animal. This review aims to discuss these opportunities from the perspective of their potential application and contribution to cattle breeding. Harnessing the potential of this paradigm shift also poses some new challenges for animal scientists - and they will also be discussed.     

The ‘death roll’ of giant fossil crocodyliforms (Crocodylomorpha: Neosuchia): allometric and skull strength analysis

In the evolution of crocodylomorphs, there were at least three giant-dimension genera: Deinosuchus from late Cretaceous of North America, Sarcosuchus from middle Cretaceous of Africa and South America, and Purussaurus from Miocene of South America. It has been suggested that these predators could have fed on very large prey as dinosaurs and megamammals. The ‘death roll’ is a spinning manoeuver executed to subdue and dismember large prey; therefore, it has been previously suggested that giant cocrodylomorphs may have used this manoeuver. However, this manoeuver can generate torsional stresses in the skull. We propose a biomechanical model to estimate the capability of a crocodylomorphs for withstanding this torsional stresses. Our results show a good correlation between a ‘death roll’ capability indicator and the feeding categories related with the actual use of ‘death roll’ in 16 living species. Here, for the first time, we propose a biomechanical approach of the implications of ‘death roll’ in fossil crocodylomorphs. We suggest that Deinosuchus and Purussaurus were able to execute death roll over dinosaurs and large mammals, respectively, but Sarcosuchus probably was not. We also found some allometry effects and, finally, we discuss palaeobiological implications based on our results.     

糙皮侧耳‘驻研1号’的选育报告

糙皮侧耳‘驻研1号’通过单孢杂交育种选育而获得的优良菌株,中低温型品种,子实体叠生,菌盖扇形,颜色受温度影响,低温下呈深黑色,高温下呈深灰色。菌柄长约5cm,直径1.5cm,六七成熟时菌盖直径5-6cm,厚1cm左右。出菇整齐,菇质韧性强,商品性状好,氨基酸总含量198.1g/kg,蛋白质含量260g/kg。生产周期45-50d,生物学效率高达89.7%,适宜河南地区秋冬季栽培。     

花叶夹竹桃穴盘扦插繁殖技术研究

采用L₉(3⁴)正交试验设计,研究插穗类型(A)、生长调节剂种类(B)及其浓度(C)对花叶夹竹桃插穗生根和苗木生理指标的影响。结果表明,影响花叶夹竹桃插穗生根和扦插苗生理指标的主要因素是插穗类型和生长调节剂种类;筛选出花叶夹竹桃扦插的最佳组合为A₁B₁C₁,即以木质化程度较轻的上部枝条作为插穗,用200 mg/L NAA处理,进行扦插育苗效果最好。     

中国传统菊花品种‘小林静’再生及转化体系的建立

以中国传统菊花品种‘小林静’叶片为外植体,建立了‘小林静’较好的再生体系及遗传转化体系.结果表明,‘小林静’叶盘最适不定芽分化培养基为MS+2.0 mg/L 6-BA+1.5 mg/L NAA,不定芽分化率为92.76％,平均再生不定芽数为2.3767个;试管苗最佳生根培养基为1/2MS,生根率达100％.移栽采用灭菌的蛭石,再生苗移栽成活率达90％以上.采用根癌农杆菌C58C1介导的叶盘转化法进行‘小林静’的遗传转化试验,农杆菌OD600=0.5-0.6,侵染10 min后,将叶片外植体接种到MS+2.0 mg/L 6-BA+1.5mg/L NAA的培养基中黑暗共培养2d,之后转接到附加10 mg/L硫酸卡那霉素和400 mg/L羧苄青霉素的分化筛选培养基中进行转化细胞的筛选,待长出抗性芽后转接至生根培养基中进行培养,最终建立了菊花品种‘小林静’的遗传转化体系.     

Defining immigrant newcomers in new destinations: symbolic boundaries in Williamsburg,Virginia

Abstract

This article examines media representations of immigration in Williamsburg, Virginia, a ‘new immigrant destination’ in the USA. Through a content analysis of coverage in Williamsburg's local newspaper, we explore how reporters, columnists and readers draw on nationally and internationally circulating discourses to produce public interpretations of immigration issues and construct symbolic boundaries between and among in-groups and ‘others’ in the community. ‘National boundaries drawn locally’ captures how media actors use nationally recognizable frames to interpret local issues and define the parameters of community and national belonging. ‘Localized symbolic boundaries’ take their meanings from place-based, cultural understandings, specific economic conditions and demographics in the local setting. Newspaper discussions in Williamsburg distinguish between ‘deserving’ foreign student workers (primarily from Eastern Europe and Asia) and ‘undeserving’, racialized, Latino ‘others’. Our analysis advances theories of boundary construction and holds implications for the politics of belonging more generally in other immigrant-receiving contexts.