763 research outputs found

    An annotated checklist of the jumping plant-lice (Insecta: Hemiptera: Psylloidea) from the Mercantour National Park, with seven new records for France and one new synonymy

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    A total of 68 psyllid species are listed from the Mercantour National Park in Southeast France, where a targeted collecting campaign was conducted between 2009 and 2012, as part of the project "ATBI+M" Mercantour. The insects were collected using Malaise traps, flight intercept traps and sweep nets to sample in the vegetation. Additional information on distribution, biology and host-plants is provided for each species. Seven species are recorded for the first time from France: Craspedolepta artemisiae (Foerster, 1848), Craspedolepta nebulosa (Zetterstedt, 1828), Cacopsylla propinqua (Schaefer, 1949), Cyamophila prohaskai (Priesner, 1927), Eryngiofaga cf. refuga (Loginova, 1966), Bactericera parastriola Conci, Ossiannilsson & Tamanini, 1988 and Trioza flixiana Burckhardt & Lauterer, 2002. Trioza (Trioza) rapisardai Conci & Tamanini, 1984 is a new subjective synonym of Trioza brachyceraea Hodkinson & White, 1979, which was previously known only from the male holotype. The abundance, distribution and introduction status of some species are discussed

    Two introduced psyllid species (Hemiptera, Psylloidea) in Brazilian eucalypt plantations.

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    1 CD-ROM. Autoria bilíngue: CONGRESSO E EXPOSICAO INTERNACIONAL SOBRE FLORESTAS, 5., 1999, Curitiba

    Versatile Coordination of Cyclopentadienyl-Arene Ligands and Its Role in Titanium-Catalyzed Ethylene Trimerization

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    Cationic titanium(IV) complexes with ansa-(η5-cyclopentadienyl,η6-arene) ligands were synthesized and characterized by X-ray crystallography. The strength of the metal-arene interaction in these systems was studied by variable-temperature NMR spectroscopy. Complexes with a C1 bridge between the cyclopentadienyl and arene moieties feature hemilabile coordination behavior of the ligand and consequently are active ethylene trimerization catalysts. Reaction of the titanium(IV) dimethyl cations with CO results in conversion to the analogous cationic titanium(II) dicarbonyl species. Metal-to-ligand backdonation in these formally low-valent complexes gives rise to a strongly bonded, partially reduced arene moiety. In contrast to the η6-arene coordination mode observed for titanium, the more electron-rich vanadium(V) cations [cyclopentadienyl-arene]V(NiPr2)(NC6H4-4-Me)+ feature η1-arene binding, as determined by a crystallographic study. The three different metal-arene coordination modes that we experimentally observed model intermediates in the cycle for titanium-catalyzed ethylene trimerization. The nature of the metal-arene interaction in these systems was studied by DFT calculations.

    Anti-Fas Induces Hepatic Chemokines and Promotes Inflammation by an NF-κB-independent, Caspase-3-dependent Pathway

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    Agonistic antibodies against the Fas receptor, when administered to mice in vivo, cause significant apoptosis in the liver. In this study we show that anti-Fas antibody not only causes apoptosis of liver cells but also provokes hepatic inflammation. Two hours after injection of anti-Fas, when mice displayed evidence of caspase-3 activation and apoptosis, we found significant hepatic induction of the CXC chemokines macrophage inflammatory protein-2 and KC. Coincident with the chemokine induction was infiltration of the hepatic parenchyma by neutrophils. Neutralization experiments identified that chemokines were the cause of Fas-induced hepatic inflammation, with KC having the predominant effect. Chemokine induction in the livers of anti-Fas-treated mice was not associated with activation of NF-kappa B. Instead, it coincided with nuclear translocation of activator protein-1 (AP-1). AP-1 activation in liver was detected 1-2 h after anti-Fas treatment, suggesting a connection to the onset of apoptosis. When apoptosis was prevented by pretreating mice with a caspase-3 inhibitor, AP-1 activation and hepatic chemokine production were both significantly reduced. Hepatic inflammation was also reduced by 70%. Taken together, these findings indicate that Fas ligation can induce inflammation in the liver in vivo. Inflammation does not arise from Fas-mediated signaling through NF-kappa B; rather, it represents an indirect effect, requiring activation of caspase-3 and nuclear translocation of AP-1

    Mitochondrial echoes of first settlement and genetic continuity in El Salvador

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    Background: From Paleo-Indian times to recent historical episodes, the Mesoamerican isthmus played an important role in the distribution and patterns of variability all around the double American continent. However, the amount of genetic information currently available on Central American continental populations is very scarce. In order to shed light on the role of Mesoamerica in the peopling of the New World, the present study focuses on the analysis of the mtDNA variation in a population sample from El Salvador. Methodology/Principal Findings: We have carried out DNA sequencing of the entire control region of the mitochondrial DNA (mtDNA) genome in 90 individuals from El Salvador. We have also compiled more than 3,985 control region profiles from the public domain and the literature in order to carry out inter-population comparisons. The results reveal a predominant Native American component in this region: by far, the most prevalent mtDNA haplogroup in this country (at ~90%) is A2, in contrast with other North, Meso- and South American populations. Haplogroup A2 shows a star-like phylogeny and is very diverse with a substantial proportion of mtDNAs (45%; sequence range 16090–16365) still unobserved in other American populations. Two different Bayesian approaches used to estimate admixture proportions in El Salvador shows that the majority of the mtDNAs observed come from North America. A preliminary founder analysis indicates that the settlement of El Salvador occurred about 13,400±5,200 Y.B.P.. The founder age of A2 in El Salvador is close to the overall age of A2 in America, which suggests that the colonization of this region occurred within a few thousand years of the initial expansion into the Americas. Conclusions/Significance: As a whole, the results are compatible with the hypothesis that today's A2 variability in El Salvador represents to a large extent the indigenous component of the region. Concordant with this hypothesis is also the observation of a very limited contribution from European and African women (~5%). This implies that the Atlantic slave trade had a very small demographic impact in El Salvador in contrast to its transformation of the gene pool in neighbouring populations from the Caribbean facade

    Micro-CT study of male genitalia and reproductive system of the Asian citrus psyllid, Diaphorina citri Kuwayama, 1908 (Insecta: Hemiptera, Liviidae)

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    The Asian citrus psyllid (ACP), Diaphorina citri, is a major vector of the bacteria Candidatus Liberibacter asiaticus and C.L. americanus, which cause Huanglongbing disease (HLB) (aka Citrus greening disease), considered the most serious bacterial disease of citrus trees. As part of a multidisciplinary project on psyllid biology (www.citrusgreening.org), the results presented here concern a detailed anatomical study of the male reproductive system (testes, seminal vesicles, accessory glands, sperm pump, connecting ducts, and aedeagus) using micro-computed tomography (micro-CT). The study summarizes current knowledge on psyllids male reproductive system and represents significant advances in the knowledge of ACP anatomy.This work was supported by USDA-NIFA Award 2014-70016-23028 ªDeveloping an Infrastructure and Product Test Pipeline to Deliver Novel Therapies for Citrus Greening Diseaseº, 2015-2020
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