180 research outputs found

    Transgenic Anopheles gambiae expressing an antimalarial peptide suffer no significant fitness cost

    Get PDF
    Mosquito-borne diseases present some of the greatest health challenges faced by the world today. In many cases, existing control measures are compromised by insecticide resistance, pathogen tolerance to drugs and the lack of effective vaccines. In light of these difficulties, new genetic tools for disease control programmes, based on the deployment of genetically modified mosquitoes, are seen as having great promise. Transgenic strains may be used to control disease transmission either by suppressing vector populations or by replacing susceptible with refractory genotypes. In practice, the fitness of the transgenic strain relative to natural mosquitoes will be a critical determinant of success. We previously described a transgenic strain of Anopheles gambiae expressing the Vida3 peptide into the female midgut following a blood-meal, which exhibited significant protection against malaria parasites. Here, we investigated the fitness of this strain relative to non-transgenic controls through comparisons of various life history traits. Experiments were designed, as far as possible, to equalize genetic backgrounds and heterogeneity such that fitness comparisons focussed on the presence and expression of the transgene cassette. We also employed reciprocal crosses to identify any fitness disturbance associated with inheritance of the transgene from either the male or female parent. We found no evidence that the presence or expression of the effector transgene or associated fluorescence markers caused any significant fitness cost in relation to larval mortality, pupal sex ratio, fecundity, hatch rate or longevity of blood-fed females. In fact, fecundity was increased in transgenic strains. We did, however, observe some fitness disturbances associated with the route of inheritance of the transgene. Maternal inheritance delayed male pupation whilst paternal inheritance increased adult longevity for both males and unfed females. Overall, in comparison to controls, there was no evidence of significant fitness costs associated with the presence or expression of transgenes in this strain

    SSR Polymorphism of Alligator sinesis and Conservation Strategy of Genetic Diversity

    Get PDF
    作者简介: 黄 磊( 1978- ) , 硕士研究生, 研究方向: 动物分子遗传 通讯作者。E-mail:wangyqnj@ jlonline. com[中文文摘]扬子鳄 (Alligatorsinensis)是中国特有的珍稀保护动物 ,为保护这一濒危物种 ,我国于 80年代初在安徽宣州先后建立了扬子鳄繁殖研究中心和国家级扬子鳄自然保护区 ,现饲养种群存鳄数量已达 10 0 0 0余头。为了揭示扬子鳄种群的遗传结构 ,共采集了 3 9个个体的样品 ,其中包括 6件剥制标本 ,按代系不同 ,分为野生群、F1代饲养群及F2 代饲养群 ,用微卫星DNA分子标记对其进行研究。分析结果显示 :扬子鳄种群在微卫星水平表现出很低的遗传多样性 ,平均等位基因数A =2 3 8,平均有效等位基因数Ne=1 60 ,平均观察杂合度Ho=0 3 74,平均期望杂合度He=0 3 50 ,平均多态信息含量PIC =0 3 2 7,3个群体间A、Ne、Ho、He、PIC及各微卫星位点等位基因频率分布无显著差异 ,但F2 代饲养群在Ami μ 6和Ami μ 2 2 2两个位点表现出极显著的遗传不平衡。扬子鳄种群遗传多样性水平低下的主要原因是近几十年来种群数量大幅减少造成 ,现阶段应将全部现存的扬子鳄作为一个整体加以保护 ,在建立新的繁殖群体时 ,应考虑保存物种遗传多样性所必需的有效种群大小 ,在种群的遗传管理上应注重低频等位基因的发现和保持.[英文文摘]Chinese alligator, Alligator sinesis , is a critically endangered endemic species under legislative protection. Results of recent investigations revealed that the number of the alligator was continuously declining in the past 50 years and less than 150 individuals were surviving in the wild until 2000. In order to prevent the extinguishing of this species, the Reproductive Research Center of Alligator sinesis and the National Nature Reserve of Alligator sinesis were set up in early 1980 s in Xuanzhou, Anhui Province. After 20 years of breeding efforts, the number of captive individuals has been brought up to more than 10, 000 in total. In order to reveal the genetic structure of Chinese alligator population, total of 39 individuals including 7 wild individuals outside of the research center were sampled to construct wild, F1 and F2 groups according to their generations, and 10 micorsatellite loci selected from 25 primer pairs originally designed for Alligator mississippiensis were employed for investigating the genetic diversity of Alligator sinesis .The results indicated that, contrasting with Alligator mississippiensis and some other endangered species, Chinese alligator had an extremely low genetic diversity level with A= 2.38, Ne= 1.60, Ho= 0.374, He= 0.350 and PIC= 0.327. There were no significant differences of A, Ne , Ho , He , PIC and each SSR locus alleles frequency distribution among 3 groups. However, Hardy Weinberg equilibrium analysis revealed that F2 captive group showed a remarkable genetic disequilibrium at loci Ami μ 6 and Ami μ 6 222 . The reason accounting for the current genetic status of Chinese alligator is dramatically shrink of the population in past decades. Due to the lack of significant difference between wild group and captive group, all survived Chinese alligator should be treated as one ESU in the next conservation practice. More attention regarding the effective population size and low frequency alleles should be emphasized in genetic management of captive alligators and establishing new separate propagation.教育部骨干教师资助计划项目(编号:GG18021002403 1740);教育部留学回国人员启动基金资

    Facial Attractiveness

    Get PDF
    Facial attractiveness has important social consequences. Despite a widespread belief that beauty cannot be defined, in fact, there is considerable agreement across individuals and cultures on what is found attractive. By considering that attraction and mate choice are critical components of evolutionary selection, we can better understand the importance of beauty. There are many traits that are linked to facial attractiveness in humans and each may in some way impart benefits to individuals who act on their preferences. If a trait is reliably associated with some benefit to the perceiver, then we would expect individuals in a population to find that trait attractive. Such an approach has highlighted face traits such as age, health, symmetry, and averageness, which are proposed to be associated with benefits and so associated with facial attractiveness. This view may postulate that some traits will be universally attractive; however, this does not preclude variation. Indeed, it would be surprising if there existed a template of a perfect face that was not affected by experience, environment, context, or the specific needs of an individual. Research on facial attractiveness has documented how various face traits are associated with attractiveness and various factors that impact on an individual's judgments of facial attractiveness. Overall, facial attractiveness is complex, both in the number of traits that determine attraction and in the large number of factors that can alter attraction to particular faces. A fuller understanding of facial beauty will come with an understanding of how these various factors interact with each other

    Personalisation and recommender systems in digital libraries

    Get PDF
    Widespread use of the Internet has resulted in digital libraries that are increasingly used by diverse communities of users for diverse purposes and in which sharing and collaboration have become important social elements. As such libraries become commonplace, as their contents and services become more varied, and as their patrons become more experienced with computer technology, users will expect more sophisticated services from these libraries. A simple search function, normally an integral part of any digital library, increasingly leads to user frustration as user needs become more complex and as the volume of managed information increases. Proactive digital libraries, where the library evolves from being passive and untailored, are seen as offering great potential for addressing and overcoming these issues and include techniques such as personalisation and recommender systems. In this paper, following on from the DELOS/NSF Working Group on Personalisation and Recommender Systems for Digital Libraries, which met and reported during 2003, we present some background material on the scope of personalisation and recommender systems in digital libraries. We then outline the working group’s vision for the evolution of digital libraries and the role that personalisation and recommender systems will play, and we present a series of research challenges and specific recommendations and research priorities for the field

    Counteractive effects of antenatal glucocorticoid treatment on D1 receptor modulation of spatial working memory

    Get PDF
    RATIONALE: Antenatal exposure to the glucocorticoid dexamethasone dramatically increases the number of mesencephalic dopaminergic neurons in rat offspring. However, the consequences of this expansion in midbrain dopamine (DA) neurons for behavioural processes in adulthood are poorly understood, including working memory that depends on DA transmission in the prefrontal cortex (PFC). OBJECTIVES: We therefore investigated the influence of antenatal glucocorticoid treatment (AGT) on the modulation of spatial working memory by a D1 receptor agonist and on D1 receptor binding and DA content in the PFC and striatum. METHODS: Pregnant rats received AGT on gestational days 16-19 by adding dexamethasone to their drinking water. Male offspring reared to adulthood were trained on a delayed alternation spatial working memory task and administered the partial D1 agonist SKF38393 (0.3-3 mg/kg) by systemic injection. In separate groups of control and AGT animals, D1 receptor binding and DA content were measured post-mortem in the PFC and striatum. RESULTS: SKF38393 impaired spatial working memory performance in control rats but had no effect in AGT rats. D1 binding was significantly reduced in the anterior cingulate cortex, prelimbic cortex, dorsal striatum and ventral pallidum of AGT rats compared with control animals. However, AGT had no significant effect on brain monoamine levels. CONCLUSIONS: These findings demonstrate that D1 receptors in corticostriatal circuitry down-regulate in response to AGT. This compensatory effect in D1 receptors may result from increased DA-ergic tone in AGT rats and underlie the resilience of these animals to the disruptive effects of D1 receptor activation on spatial working memory

    How do you say ‘hello’? Personality impressions from brief novel voices

    Get PDF
    On hearing a novel voice, listeners readily form personality impressions of that speaker. Accurate or not, these impressions are known to affect subsequent interactions; yet the underlying psychological and acoustical bases remain poorly understood. Furthermore, hitherto studies have focussed on extended speech as opposed to analysing the instantaneous impressions we obtain from first experience. In this paper, through a mass online rating experiment, 320 participants rated 64 sub-second vocal utterances of the word ‘hello’ on one of 10 personality traits. We show that: (1) personality judgements of brief utterances from unfamiliar speakers are consistent across listeners; (2) a two-dimensional ‘social voice space’ with axes mapping Valence (Trust, Likeability) and Dominance, each driven by differing combinations of vocal acoustics, adequately summarises ratings in both male and female voices; and (3) a positive combination of Valence and Dominance results in increased perceived male vocal Attractiveness, whereas perceived female vocal Attractiveness is largely controlled by increasing Valence. Results are discussed in relation to the rapid evaluation of personality and, in turn, the intent of others, as being driven by survival mechanisms via approach or avoidance behaviours. These findings provide empirical bases for predicting personality impressions from acoustical analyses of short utterances and for generating desired personality impressions in artificial voices

    Soluble and Cell-Associated Insulin Receptor Dysfunction Correlates with Severity of HAND in HIV-Infected Women

    Get PDF
    Blood sugar metabolism abnormalities have been identified in HIV-infected individuals and associated with HIV-associated neurocognitive disorders (HAND). These abnormalities may occur as a result of chronic HIV infection, long-term use of combined antiretroviral treatment (CART), aging, genetic predisposition, or a combination of these factors, and may increase morbidity and mortality in this population.To determine if changes in soluble and cell-associated insulin receptor (IR) levels, IR substrate-1 (IRS-1) levels, and IRS-1 tyrosine phosphorylation are associated with the presence and severity of HAND in a cohort of HIV-seropositive women.This is a retrospective cross-sectional study using patient database information and stored samples from 34 HIV-seropositive women and 10 controls without history of diabetes from the Hispanic-Latino Longitudinal Cohort of Women. Soluble IR subunits [sIR, ectodomain (α) and full-length or intact (αβ)] were assayed in plasma and CSF samples by ELISA. Membrane IR levels, IRS-1 levels, and IRS-1 tyrosine phosphorylation were analyzed in CSF white cell pellets (WCP) using flow cytometry. HIV-seropositive women had significantly increased levels of intact or full-length sIR in plasma (p<0.001) and CSF (p<0.005) relative to controls. Stratified by HAND, increased levels of full-length sIR in plasma were associated with the presence (p<0.001) and severity (p<0.005) of HAND. A significant decrease in IRS-1 tyrosine-phosphorylation in the WCP was also associated with the presence (p<0.02) and severity (p<0.02) of HAND.This study provides evidence that IR secretion is increased in HIV-seropositive women, and increased IR secretion is associated with cognitive impairment in these women. Thus, IR dysfunction may have a role in the progression of HAND and could represent a biomarker for the presence and severity of HAND

    Importance of Preoperative Imaging in Acetabular Revision Surgery - A Case Report

    Get PDF
    Acetabular defects, particularly as a result of protrusion of acetabular components into the hemipelvis, may cause serious complications during revision procedures as a result of iatrogenic injury to surrounding anatomical structures. In these challenging cases, we advocate the utilisation of preoperative three dimensional imaging. MRI and CT- imaging offer superior understanding of the three-dimensional quality of bony defects and the relationship of implants to important anatomical structures. Appropriate preoperative planning may also prevent major complications during the removal of the pre-existing hardware, prior to re-implantation of implants. Potential complications include injury of nerves, blood vessels and other intrapelvic structures

    Study of the reaction e^{+}e^{-} -->J/psi\pi^{+}\pi^{-} via initial-state radiation at BaBar

    Get PDF
    We study the process e+eJ/ψπ+πe^+e^-\to J/\psi\pi^{+}\pi^{-} with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BaBar detector at center-of-mass energies 10.58 and 10.54 GeV, and correspond to an integrated luminosity of 454 fb1\mathrm{fb^{-1}}. We investigate the J/ψπ+πJ/\psi \pi^{+}\pi^{-} mass distribution in the region from 3.5 to 5.5 GeV/c2\mathrm{GeV/c^{2}}. Below 3.7 GeV/c2\mathrm{GeV/c^{2}} the ψ(2S)\psi(2S) signal dominates, and above 4 GeV/c2\mathrm{GeV/c^{2}} there is a significant peak due to the Y(4260). A fit to the data in the range 3.74 -- 5.50 GeV/c2\mathrm{GeV/c^{2}} yields a mass value 4244±54244 \pm 5 (stat) ±4 \pm 4 (syst)MeV/c2\mathrm{MeV/c^{2}} and a width value 11415+16114 ^{+16}_{-15} (stat)±7 \pm 7(syst)MeV\mathrm{MeV} for this state. We do not confirm the report from the Belle collaboration of a broad structure at 4.01 GeV/c2\mathrm{GeV/c^{2}}. In addition, we investigate the π+π\pi^{+}\pi^{-} system which results from Y(4260) decay

    Minocycline Inhibition of Monocyte Activation Correlates with Neuronal Protection in SIV NeuroAIDS

    Get PDF
    Background: Minocycline is a tetracycline antibiotic that has been proposed as a potential conjunctive therapy for HIV-1 associated cognitive disorders. Precise mechanism(s) of minocycline’s functions are not well defined. Methods: Fourteen rhesus macaques were SIV infected and neuronal metabolites measured by proton magnetic resonance spectroscopy (1H MRS). Seven received minocycline (4 mg/kg) daily starting at day 28 post-infection (pi). Monocyte expansion and activation were assessed by flow cytometry, cell traffic to lymph nodes, CD16 regulation, viral replication, and cytokine production were studied. Results: Minocycline treatment decreased plasma virus and pro-inflammatory CD14+CD16+ and CD14loCD16+ monocytes, and reduced their expression of CD11b, CD163, CD64, CCR2 and HLA-DR. There was reduced recruitment of monocyte/ macrophages and productively infected cells in axillary lymph nodes. There was an inverse correlation between brain NAA/ Cr (neuronal injury) and circulating CD14+CD16+ and CD14loCD16+ monocytes. Minocycline treatment in vitro reduced SIV replication CD16 expression on activated CD14+CD16+ monocytes, and IL-6 production by monocytes following LPS stimulation. Conclusion: Neuroprotective effects of minocycline are due in part to reduction of activated monocytes, monocyte traffic. Mechanisms for these effects include CD16 regulation, reduced viral replication, and inhibited immune activation. Citation: Campbell JH, Burdo TH, Autissier P, Bombardier JP, Westmoreland SV, et al. (2011) Minocycline Inhibition of Monocyte Activation Correlate
    corecore