根螨属螨类进境风险分析

通过对根螨进境风险进行定性分析,初步认为花叶芋根螨(Rhizoglyphus caladii)、小根螨(R.minutus)、长毛根螨(R.setosus)和单列根螨(R.singularis)为检疫性有害生物;刺足根螨(R.echinopus)和罗宾根螨(R.robini)为限定的非检疫性有害生物。     

食物对刺足根螨生长发育、繁殖及休眠体产生的影响

在(25±1)℃、(95±5)%RH、全黑暗条件下,研究了4种食物对刺足根螨生长发育、繁殖及休眠体产生的影响。结果表明:取食马铃薯、马铃薯淀粉及鱼粉后,刺足根螨能完成世代发育,但其取食滤纸不能完成世代发育;在适宜的温湿度条件下,供试的4种食物对刺足根螨休眠体的产生无影响。     

猎物对巴氏钝绥螨生长发育和繁殖的影响

在(25±1)℃、90%RH以上、无光照实验条件下,以腐食酪螨和刺足根螨为猎物,研究了巴氏钝绥螨的生长发育和繁殖情况。结果表明,以腐食酪螨幼螨为猎物,巴氏钝绥螨可正常发育和繁殖,雌、雄成螨寿命分别为(34.250±1.361)和(23.950±1.606)d;以刺足根螨为猎物时,无法发育到成螨;成螨寿命明显缩短,雌、雄分别为(7.300±0.619)和(6.567±0.609)d,显著短于捕食腐食酪螨的巴氏钝绥螨,而且雌螨不能产卵。     

根螨——一类重要地下害螨

<正> 根螨Rhizoglyphus spp,在土壤中为害植物的地下部分,是世界性的害螨。随着我国蔬菜和花卉(特别是球根、球茎类)种植面积的扩大,根螨的为害值得重视,现根据有关文献编写此文,以供参考。     

中国巨刺螨属一新种和雷氏巨刺螨的重新描述(中气门目,巨刺螨科)(英文)

记述了采自广西的扁颅蝠Tylonycteris robustula(Thomas,1915)体表的寄生革螨1新种:拟雷氏巨刺螨Macronyssus pararadovskyi Tian,Jin et Zhang,sp.nov..新种与雷氏巨刺螨Macronyssus radovskyi(Domrow,1963)近似,二者的区别在于:新种背毛有27对,具有Z3;雌螨生殖腹板具有3根副毛,或部分标本为1根副毛在板的末端,另1对副毛位于板外;雄螨胸生殖腹板上具有4对胸毛和20根腹毛.而雷氏巨刺螨背毛有26对,不具有Z3.雌螨生殖腹板不具有副毛,即副毛均不在生殖腹板上;雄螨胸生殖腹板上具有4对胸毛和18根腹毛.另外,依据采自广西褐扁颅蝠Tylonycterispachypus(Temminck,1840)体表的标本,对雷氏巨刺螨Macronyssus radovskyi(Domrow,1963)的雌、雄螨成体和第1若螨进行了重新描述.所有标本均保存于贵州大学昆虫研究所标本馆.     

刺足根螨的人工饲养技术

介绍一种人工饲养刺足根螨Rhizoglyphus echinopus(FumouzeetRobin)的技术。用马铃薯薄片法在室内已连续饲养3代,卵孵化率、幼螨、若螨存活率均超过90%,该方法可用于室内大量饲养刺足根螨。     

革螨跗感器的结构和功能

本文进一步研究了:④厩真厉螨截肢前后的爬行行为,表明第1对足其感觉功能;②用古拉广厉螨分别截各对足驱避反应的对比试验,见到只有当截去第1对足跗节时失去嗅觉功能,而截去第Ⅱ、Ⅲ、Ⅳ对足时,各组都仍有嗅觉功能;⑤对格氏血厉螨、厩真厉螨、毒厉螨和鼠颚毛厉螨进行涂漆前后的驱避试验,显示当跗感器被涂满封闭,则嗅觉功能消失;④以0.5%结晶紫或龙胆紫液染色的截肢标本,观察了厩真厉螨、毒厉螨、格氏血厉螨、古拉广厉螨及尾足螨股一种螨,足Ⅰ跗节末端凹窝中,至少都存在两类感毛,钝钉型感毛和长而尖的刚毛型感毛;⑤厩真厉螨雌螨和幼螨跗感器的钝钉毛分别为8根和5根,另外各有2根短而尖的毛,分别测定了长度,描述了形态特点;⑥透射电镜观察厩真厉螨、毒厉螨等的跗感器钝钉毛,毛外围有表皮壁,壁上有很多微孔,内有中心腔,腔内有树突。属化感器——嗅觉器;⑦电生理技术研究,当用氨和醋酸的气体刺激厩真厉螨、毒厉螨的离体足Ⅰ时,均产生明显的应激电位差,充分证明足Ⅰ辩节有嗅觉功能。     

噻虫嗪施用对二斑叶螨种群动态的影响

为了明确新烟碱类杀虫剂噻虫嗪对非靶标害虫二斑叶螨Tetranychus urticae种群的影响,本研究在玻璃温室的盆栽苗和设施大棚内,采用噻虫嗪灌根、喷雾等不同施用方式,研究了二斑叶螨的种群动态变化。盆栽苗的模拟结果表明,噻虫嗪施用后,二斑叶螨卵和成若螨的数量均显著高于清水处理;而噻虫嗪灌根处理叶螨数量在初期显著高于喷雾处理,后期无显著差异;设施棚内采用噻虫嗪进行灌根施用,发现二斑叶螨雌成螨自然种群数量也显著高于对照处理区。结果表明,噻虫嗪灌根会刺激田间叶螨种群的快速增长,因此在田间施用噻虫嗪时应特别注意对叶螨的防控。     

中国江西棉田棉足绒螨新种记述(蜱螨亚纲：绒螨科)

记述了中国江西省棉田的绒螨一新种,即棉足绒螨的幼螨后螨态。新种的成螨成其它种类的区别为须胫节仅具1根刺状毛,冠脊权有1根前中毛。     

中国拉绒螨属幼螨一新种(真螨目:约绒螨科)

拉绒螨属(Lassenia)隶于真螨目(Acariformcs)的约绒螨科(Johnstonianidae),1957年由Newell建立。该属在我国尚属初次报导。拉绒螨属的幼螨栖于潮湿环境,寄生于双翅目昆虫体上。根据以下特征可将它与其他约绒螨幼螨区分开来:躯体背面前部的盾板上有较短的前感毛、较长的后感毛、前侧毛和后侧毛各一对;喙有发达的原喙毛、第二喙毛和第三喙毛;基节Ⅱ前方有发育完好的拉氏器(Lassenia-organ);须肢跗节长圆柱形,后方有感棒一根,末端和亚末端各有荆毛一根;跗节Ⅰ和Ⅱ背荆毛基部有伴毛(Companion seta)一根(Newell,1957)。     

Ambiguities and Asymmetries in Consent and Refusal: Reply to Manson

John Harris claims that is it ‘palpable nonsense’ to suggest that ‘a child (or anyone) might competently consent to a treatment but not be competent to refuse it.’ In ‘Transitional Paternalism: How Shared Normative Powers Give Rise to the Asymmetry of Adolescent Consent and Refusal’ Neil Manson aims to explain away the apparent oddness of this asymmetry of consent and refusal, by appealing to the idea of shared normative powers, presenting joint bank accounts as an example. In this article, I will argue that Manson's account fails to explain away the oddness. Rather, I will argue that there are ambiguities to which Manson has not paid sufficient attention. In fact, as odd as it may sound, I argue that Manson actually agrees with Harris (at least in relation to the asymmetry of competence). He fails to recognize that he agrees with Harris because he is not careful enough to distinguish between different asymmetries, which I have labelled the asymmetries of choice, permissibility and competence.     

Manson's triple error

The author discusses the significance, implications and limitations of Manson's work. How did Patrick Manson resolve some of the major problems raised by the filarial worm life cycle? The Amoy physician showed that circulating embryos could only leave the blood via the percutaneous route, thereby requiring a bloodsucking insect. The discovery of a new autonomous, airborne, active host undoubtedly had a considerable impact on the history of parasitology, but the way in which Manson formulated and solved the problem of the transfer of filarial worms from the body of the mosquito to man resulted in failure. This article shows how the epistemological transformation operated by Manson was indissociably related to a series of errors and how a major breakthrough can be the result of a series of false proposals and, consequently, that the history of truth often involves a history of error.     

The roles of two amino acid residues in the active site of L-lactate monooxygenase. Mutation of arginine 187 to methionine and histidine 240 to glutamine.

Lactate monooxygenase (LMO) catalyzes the conversion of L-lactate to acetate, CO(2), and water with the incorporation of molecular oxygen. Arginine 187 of LMO is highly conserved within the family of L-alpha-hydroxyacid oxidizing enzymes (Lê, K. H. D., and Lederer, F. (1991) J. Biol. Chem. 266, 20877-20881). By comparison with the equivalent residue in flavocytochrome b(2) from Saccharomyces cerevisiae (Pike, A. D., Chapman, S. K, Manson, F. D. C,. Reid, G. A. , Gondry, M., and Lederer, F. (1996) in Flavins and Flavoproteins (Stevenson, K. J., Massey, V., and Williams, C. H., Jr., eds) pp. 571-574, University of Calgary Press, Calgary, AB, Canada), arginine 187 might be expected to have an important role in catalytic efficiency and substrate binding in LMO. Histidine 240 is predicted to be close to the substrate binding site of LMO, although it is not conserved within the enzyme family. Arginine 187 has been replaced with methionine (R187M), and histidine 240 has been replaced with glutamine (H240Q). L-Lactate oxidation by R187M is very slow. The binding of L-lactate to the mutant enzyme appears to be very weak, as is the binding of oxalate, a transition state analogue. The binding of pyruvate to the reduced enzyme is also very weak, resulting in complete uncoupling of enzyme turnover, with H(2)O(2) and pyruvate as the final products. In addition, anionic forms of the flavin are unstable. The K(d) for sulfite is increased nearly 400-fold by this mutation. The semiquinone form of R187M is also thermodynamically unstable, although the overall midpoint potential for the two-electron reduction of R187M is only 34 mV lower than for the wild-type enzyme. H240Q more closely resembles the wild-type enzyme. The steady-state activity of H240Q is completely coupled. The k(cat) is similar to that for the wild-type enzyme.     

Ronald Ross and the malaria-mosquito cycle

This essay examines briefly Ronald Ross's research on malaria in India between 1895 and 1899, during which time he elucidated the role of the Anopheles mosquito in the transmission of the disease. During his crucial experimental work in 1898, he used birds, human malaria being relatively uncommon in Calcutta. This article is based largely on the correspondence between Ross and Patrick Manson, which has just been edited.     

Neutralizing Antibodies in Sera from Macaques Immunized with Attenuated Simian Immunodeficiency Virus

Infection with attenuated simian immunodeficiency virus (SIV) in rhesus macaques has been shown to raise antibodies capable of neutralizing an animal challenge stock of primary SIVmac251 in CEMx174 cells that correlate with resistance to infection after experimental challenge with this virulent virus (M. S. Wyand, K. H. Manson, M. Garcia-Moll, D. C. Montefiori, and R. C. Desrosiers, J. Virol. 70:3724–3733, 1996). Here we show that these neutralizing antibodies are not detected in human and rhesus peripheral blood mononuclear cells (PBMC). In addition, neutralization of primary SIVmac251 in human and rhesus PBMC was rarely detected with plasma samples from a similar group of animals that had been infected either with SIVmac239Δnef for 1.5 years or with SIVmac239Δ3 for 3.2 years, although low-level neutralization was detected in CEMx174 cells. Potent neutralization was detected in CEMx174 cells when the latter plasma samples were assessed with laboratory-adapted SIVmac251. In contrast to primary SIVmac251, laboratory-adapted SIVmac251 did not replicate in human and rhesus PBMC despite its ability to utilize CCR5, Bonzo/STRL33, and BOB/gpr15 as coreceptors for virus entry. These results illustrate the importance of virus passage history and the choice of indicator cells for making assessments of neutralizing antibodies to lentiviruses such as SIV. They also demonstrate that primary SIVmac251 is less sensitive to neutralization in human and rhesus PBMC than it is in established cell lines. Results obtained in PBMC did not support a role for neutralizing antibodies as a mechanism of protection in animals immunized with attenuated SIV and challenged with primary SIVmac251.     

The malariology centenary

The year 1898 was one of the most significant years in the history of malariology. One hundred years later scientists gathered at the Accademia Nazionale dei Lincei, Rome, to commemorate the Malariology Centenary. This paper provides a short overview of some of the key developments and discoveries in malaria research which took place at the end of the 19th century. The major contributions of Alphonse Laveran, Patrick Manson, Ronald Ross, Battista Grassi and a number of scientists of the Italian School of Malariology to the understanding of the transmission of malaria by Anopheles mosquitoes are described. This paper also highlights the importance of an historical perspective in furthering our understanding of the 'Malaria Challenge after One Hundred Years of Malariology'.     

The human bitter taste receptor, hTAS2R16, discriminates slight differences in the configuration of disaccharides

Sweetness and bitterness are key determinants of food acceptance and rejection, respectively. Sugars, such as sucrose and fructose, are generally recognized as sweet. However, not all sugars are sweet, and even anomers may have quite different tastes. For example, gentiobiose is bitter, whereas its anomer, isomaltose, is sweet. Despite this unique sensory character, the molecular basis of the bitterness of gentiobiose remains to be clarified. In this study, we used calcium imaging analysis of human embryonic kidney 293T cells that heterologously expressed human taste receptors to demonstrate that gentiobiose activated hTAS2R16, a bitter taste receptor, but not hT1R2/hT1R3, a sweet taste receptor. In contrast, isomaltose activated hT1R2/hT1R3. As a result, these anomers elicit different taste sensations. Mutational analysis of hTAS2R16 also indicated that gentiobiose and β-d-glucopyranosides, such as salicin share a common binding site of hTAS2R16.     

Tumor suppression in the absence of p53-mediated cell-cycle arrest, apoptosis, and senescence

Cell-cycle arrest, apoptosis, and senescence are widely accepted as the major mechanisms by which p53 inhibits tumor formation. Nevertheless, it remains unclear whether they are the rate-limiting steps in tumor suppression. Here, we have generated mice bearing lysine to arginine mutations at one (p53(K117R)) or three (p53(3KR); K117R+K161R+K162R) of p53 acetylation sites. Although p53(K117R/K117R) cells are competent for p53-mediated cell-cycle arrest and senescence, but not apoptosis, all three of these processes are ablated in p53(3KR/3KR) cells. Surprisingly, unlike p53 null mice, which rapidly succumb to spontaneous thymic lymphomas, early-onset tumor formation does not occur in either p53(K117R/K117R) or p53(3KR/3KR) animals. Notably, p53(3KR) retains the ability to regulate energy metabolism and reactive oxygen species production. These findings underscore the crucial role of acetylation in differentially modulating p53 responses and suggest that unconventional activities of p53, such as metabolic regulation and antioxidant function, are critical for suppression of early-onset spontaneous tumorigenesis.     

Lethal intergroup aggression by chimpanzees in Kibale National Park, Uganda

Chimpanzees (Pan troglodytes) have hostile intergroup relations throughout most or all of their geographic range. Hostilities include aggressive encounters between members of neighboring communities during foraging and during patrols in which members of one community search for neighbors near territory boundaries. Attacks on neighbors involve coalitions of adult males, and are sometimes fatal. Targets include members of all age/sex classes, but the risk of lethal intergroup coalitionary aggression is highest for adult males and infants, and lowest for sexually swollen females. The best-supported adaptive explanation for such behavior is that fission-fusion sociality allows opportunities for low-cost attacks that, when successful, enhance the food supply for members of the attackers' community, improve survivorship, and increase female fertility. We add to the database on intergroup coalitionary aggression in chimpanzees by describing three fatal attacks on adult males, plus a fourth attack on an adult male and an attack on a juvenile that were almost certainly fatal. Observers saw four of these attacks and inferred the fifth from forensic and behavioral evidence. The attackers were males in two habituated, unprovisioned communities (Ngogo and Kanyawara) in Kibale National Park, Uganda. We also summarize data on other intercommunity attacks at Ngogo. Our observations are consistent with the "imbalance of power" hypothesis [Manson & Wrangham, Current Anthropology 32:369-390, 1991] and support the argument that lethal coalitionary intergroup aggression by male chimpanzees is part of an evolved behavioral strategy.     

R391: a conjugative integrating mosaic comprised of phage,plasmid, and transposon elements

The conjugative, chromosomally integrating element R391 is the archetype of the IncJ class of mobile genetic elements. Originally found in a South African Providencia rettgeri strain, R391 carries antibiotic and mercury resistance traits, as well as genes involved in mutagenic DNA repair. While initially described as a plasmid, R391 has subsequently been shown to be integrated into the bacterial chromosome, employing a phage-like integration mechanism closely related to that of the SXT element from Vibrio cholerae O139. Analysis of the complete 89-kb nucleotide sequence of R391 has revealed a mosaic structure consisting of elements originating in bacteriophages and plasmids and of transposable elements. A total of 96 open reading frames were identified; of these, 30 could not be assigned a function. Sequence similarity suggests a relationship of large sections of R391 to sequences from Salmonella, in particular those corresponding to the putative conjugative transfer proteins, which are related to the IncHI1 plasmid R27. A composite transposon carrying the kanamycin resistance gene and a novel insertion element were identified. Challenging the previous assumption that IncJ elements are plasmids, no plasmid replicon was identified on R391, suggesting that they cannot replicate autonomously.