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101.
González S Moreno-Delgado D Moreno E Pérez-Capote K Franco R Mallol J Cortés A Casadó V Lluís C Ortiz J Ferré S Canela E McCormick PJ 《PLoS biology》2012,10(6):e1001347
The role of the pineal gland is to translate the rhythmic cycles of night and day encoded by the retina into hormonal signals that are transmitted to the rest of the neuronal system in the form of serotonin and melatonin synthesis and release. Here we describe that the production of both melatonin and serotonin by the pineal gland is regulated by a circadian-related heteromerization of adrenergic and dopamine D4 receptors. Through α1
B-D4 and β1-D4 receptor heteromers dopamine inhibits adrenergic receptor signaling and blocks the synthesis of melatonin induced by adrenergic receptor ligands. This inhibition was not observed at hours of the day when D4 was not expressed. These data provide a new perspective on dopamine function and constitute the first example of a circadian-controlled receptor heteromer. The unanticipated heteromerization between adrenergic and dopamine D4 receptors provides a feedback mechanism for the neuronal hormone system in the form of dopamine to control circadian inputs. 相似文献
102.
Rapid immunofluorescent determination of cells in the S phase in pea root meristems: An alternative to autoradiography 总被引:2,自引:0,他引:2
Photosystem II (PS II) activity and the localization of ribulose-l,5-bisphosphate (RuBP) carboxylase (EC 4.1.1.39) were studied in primary leaves of young maize plants ( Zea mays L. cv. Fronica) by tetra-nitro-blue-tetrazoliumchloride reduction and immunolocalization, respectively. In tissue of 3-day-old plants all chloroplasts were structurally identical. From day 4 they developed into their typical appearance of mesophyll and bundle sheath chloroplasts. First PS II-activity was present in both types of chloroplasts. From day 4 it disappeared in bundle sheath chloroplasts concomitant with the loss of grana. RuBP carboxylase on the other hand was only present in bundle sheath chloroplasts at all stages of development. Thus, the control of the development of the photosystems and the Calvin cycle enzymes seem to differ. 相似文献
103.
Yannery Gómez-Bonilla Miguel López-Ferber Primitivo Caballero Rosa Murillo Delia Muñoz 《BioControl》2013,58(2):215-224
The control efficiency of a Phthorimaea operculella granulovirus isolate from Costa Rica (PhopGV-CR1) against the concurrent insect pests P. operculella (Zeller) and Tecia solanivora (Povolny) (Lepidoptera: Gelechiidae) was evaluated. In warehouses, the best control efficiency was achieved with a powder formulate applied inside bags, which reduced injury over 70 % compared with the untreated controls. In the field, liquid and powder virus formulations significantly reduced injury between 56.2 and 81.7 % compared with the untreated controls, and were as efficient as chemical treatments. The efficiency of formulations stored at ?20 °C for six months (liquid) or at ambient temperature for three months (powder) was maintained, but higher temperatures and/or longer exposure times resulted in loss of pathogenicity. The data presented here favor the inclusion of granulovirus formulations of PhopGV-CR1 in Integrated Pest Management programs against tuberworms in Costa Rica and give clues on storage conditions for the growers in this country. 相似文献
104.
The quality and availability of resources influence the geographical distribution of species. Social species need safe places to rest, meet, exchange information and obtain thermoregulatory benefits, but those places may also serve other important functions that have been overlooked in research. We use a large soaring bird that roosts communally in cliffs, the Andean condor (Vultur gryphus), as a model species to elucidate whether roost locations serve as a refuge from adverse weather conditions (climatic refuge hypothesis, CRH), and/or from predators or anthropogenic disturbances (threats refuge hypothesis, TRH). The CRH predicts that communal roosts will face in the opposite direction from where storms originate, and will be located in climatically stable, low precipitation areas. The TRH predicts that communal roosts will be large, poorly accessible cliffs, located far from human-made constructions. We surveyed cliffs used as communal roosts by condors in northwestern Patagonia, and compared them with alternative non-roosting cliffs to test these predictions at local and regional scales. We conclude that communal roosting places provide refuge against climate and disturbances such as, for instance, the threats of predators (including humans). Thus, it is not only the benefits gained from being aggregated per se, but the characteristics of the place selected for roosting that may both be essential for the survival of the species. This should be considered in management and conservation plans given the current scenario of global climate change and the increase in environmental disturbances. 相似文献
105.
Sergio Cardoso Laura Valverde Miguel A. Alfonso-Sánchez Leire Palencia-Madrid Xabier Elcoroaristizabal Jaime Algorta Susana Catarino David Arteta Rene J. Herrera María Teresa Zarrabeitia José A. Pe?a Marian M. de Pancorbo 《PloS one》2013,8(7)
The European genetic landscape has been shaped by several human migrations occurred since Paleolithic times. The accumulation of archaeological records and the concordance of different lines of genetic evidence during the last two decades have triggered an interesting debate concerning the role of ancient settlers from the Franco-Cantabrian region in the postglacial resettlement of Europe. Among the Franco-Cantabrian populations, Basques are regarded as one of the oldest and more intriguing human groups of Europe. Recent data on complete mitochondrial DNA genomes focused on macrohaplogroup R0 revealed that Basques harbor some autochthonous lineages, suggesting a genetic continuity since pre-Neolithic times. However, excluding haplogroup H, the most representative lineage of macrohaplogroup R0, the majority of maternal lineages of this area remains virtually unexplored, so that further refinement of the mtDNA phylogeny based on analyses at the highest level of resolution is crucial for a better understanding of the European prehistory. We thus explored the maternal ancestry of 548 autochthonous individuals from various Franco-Cantabrian populations and sequenced 76 mitogenomes of the most representative lineages. Interestingly, we identified three mtDNA haplogroups, U5b1f, J1c5c1 and V22, that proved to be representative of Franco-Cantabria, notably of the Basque population. The seclusion and diversity of these female genetic lineages support a local origin in the Franco-Cantabrian area during the Mesolithic of southwestern Europe, ∼10,000 years before present (YBP), with signals of expansions at ∼3,500 YBP. These findings provide robust evidence of a partial genetic continuity between contemporary autochthonous populations from the Franco-Cantabrian region, specifically the Basques, and Paleolithic/Mesolithic hunter-gatherer groups. Furthermore, our results raise the current proportion (≈15%) of the Franco-Cantabrian maternal gene pool with a putative pre-Neolithic origin to ≈35%, further supporting the notion of a predominant Paleolithic genetic substrate in extant European populations. 相似文献
106.
Roberto Bovara Giacomo Carrea Sergio Riva Francesco Secundo 《Biotechnology letters》1996,18(3):305-308
Summary Cholic acid (3,7,12-trihydroxy-5-cholanoic acid) was completely and selectively transformed into 12-ketoursodeoxycholic acid (3,7-dihydroxy-12-oxo-5-cholanoic acid) by means of two consecutive enzymatic steps catalyzed, the first, by 7- and 12-hydroxysteroid dehydrogenase and, the second, by 7-hydroxysteroid dehydrogenase. Coenzyme regeneration was carried out with -ketoglutarate-glutamate dehydrogenase and glucose-glucose dehydrogenase, respectively. 相似文献
107.
Martina Ferraguti Sergio Magallanes Jéssica Jiménez-Peñuela Josué Martínez-de la Puente Luz Garcia-Longoria Jordi Figuerola Jaime Muriel Tamer Albayrak Staffan Bensch Camille Bonneaud Rohan H. Clarke Gábor Á. Czirják Dimitar Dimitrov Kathya Espinoza John G. Ewen Farah Ishtiaq Wendy Flores-Saavedra László Zsolt Garamszegi Olof Hellgren Dita Horakova Kathryn P. Huyvaert Henrik Jensen Asta Križanauskienė Marcos R. Lima Charlene Lujan-Vega Eyðfinn Magnussen Lynn B. Martin Kevin D. Matson Anders Pape Møller Pavel Munclinger Vaidas Palinauskas Péter L. Pap Javier Pérez-Tris Swen C. Renner Robert Ricklefs Sergio Scebba Ravinder N. M. Sehgal Manuel Soler Eszter Szöllősi Gediminas Valkiūnas Helena Westerdahl Pavel Zehtindjiev Alfonso Marzal 《Global Ecology and Biogeography》2023,32(5):809-823
Aim
The increasing spread of vector-borne diseases has resulted in severe health concerns for humans, domestic animals and wildlife, with changes in land use and the introduction of invasive species being among the main possible causes for this increase. We explored several ecological drivers potentially affecting the local prevalence and richness of avian malaria parasite lineages in native and introduced house sparrows (Passer domesticus) populations.Location
Global.Time period
2002–2019.Major taxa studied
Avian Plasmodium parasites in house sparrows.Methods
We analysed data from 2,220 samples from 69 localities across all continents, except Antarctica. The influence of environment (urbanization index and human density), geography (altitude, latitude, hemisphere) and time (bird breeding season and years since introduction) were analysed using generalized additive mixed models (GAMMs) and random forests.Results
Overall, 670 sparrows (30.2%) were infected with 22 Plasmodium lineages. In native populations, parasite prevalence was positively related to urbanization index, with the highest prevalence values in areas with intermediate urbanization levels. Likewise, in introduced populations, prevalence was positively associated with urbanization index; however, higher infection occurred in areas with either extreme high or low levels of urbanization. In introduced populations, the number of parasite lineages increased with altitude and with the years elapsed since the establishment of sparrows in a new locality. Here, after a decline in the number of parasite lineages in the first 30 years, an increase from 40 years onwards was detected.Main conclusions
Urbanization was related to parasite prevalence in both native and introduced bird populations. In invaded areas, altitude and time since bird introduction were related to the number of Plasmodium lineages found to be infecting sparrows. 相似文献108.
A. Escribano T. Williams D. Goulson R. D. Cave J. W. Chapman P. Caballero 《Biocontrol Science and Technology》2001,11(5):649-662
Nucleopolyhedroviruses ( Baculoviridae ) are virulent insect pathogens that generally show a high degree of host specificity and have recognized potential as biological insecticides. Whenever viruses are applied for pest control, a proportion of the infected insects will also be parasitized by hymenopteran or dipteran parasitoids and interspecific competition for host resources will occur; the severity of such competition is likely to be modulated to a large degree by the virulence of each type of parasite. We examined the impact of parasitism by the solitary egg-larval endoparasitoid Chelonus insularis (Hymenoptera: Braconidae) on the speed of kill of nucleopolyhedrovirus-infected Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae and the pattern of host growth and virus production in infected and/or parasitized hosts. We also examined the effect of parasitism on the virulence, infectivity and genetic composition of serially passaged virus. Both parasitism and viral infection resulted in a marked reduction in host growth. When third instar larvae were dually parasitized and virus-infected, the growth rate was even more severely affected compared to parasitized larvae. There was a significant increase in virus production in larvae infected at later instars. Interspecific competition resulted in a substantial decrease in pathogen production in parasitized larvae infected at the fourth instar, but not in parasitized larvae infected at earlier instars. The serial passage experiment resulted in the appearance of four distinct genetic isolates of the virus detected by restriction endonuclease analysis. Of the three isolates that appeared in nonparasitized larvae, two showed increased virulence, expressed by mean time to death, and for one of these the infectivity, expressed as LC 50 , was reduced. One isolate that appeared in parasitized larvae (isolate D) had increased virulence and infectivity. Southern blot analysis indicated that virus isolate D was most likely generated by point mutation of a restriction site or by alterations such as duplications, deletions or by recombination of two or more genotypic variants present in the wild-type nucleopolyhedrovirus isolate. Our study provides clear evidence of interspecific competition within the host, since, depending on the timing of inoculation, adverse effects were observed upon both the parasitoid and the virus. 相似文献
109.
Absolute Configuration Assignment of a Paraconic Acid Derivative via Vibrational Circular Dichroism Spectroscopy and Density Functional Theory Calculation 下载免费PDF全文
Sara Meninno Paola Rizzo Sergio Abbate Giovanna Longhi Giuseppe Mazzeo Guglielmo Monaco Alessandra Lattanzi Riccardo Zanasi 《Chirality》2016,28(2):110-115
Density functional theory calculation of the vibrational circular dichroism spectrum was used to assign the absolute configuration of an all‐carbon quaternary β‐stereocenter of a γ‐butyrolactone recently synthesized through an asymmetric organocatalytic tandem aldol/lactonization sequence. Comparison with the experimental spectrum is satisfactory, on account of the fact that spectroscopic features are weak due to the presence of multiple conformers. As a result, the (R) absolute configuration was assigned to the (+) optical isomer. Chirality 28:110–115, 2016. © 2015 Wiley Periodicals, Inc. 相似文献
110.
The status of the taxa morphologically similar to Pluteus eugraptus (Basidiomycota, Agaricales) was investigated with morphological and molecular (ITS region) characters. This group of species belongs in Pluteus sect. Celluloderma based on morphological and molecular characters. Two species, Pluteus multiformis, from Spain and Pluteus eludens from Madeira, Portugal, Russia and USA, are described as new. Both species share pigmented cheilocystidia and a pileipellis composed of both clavate-spheropedunculate and elongated elements with P. eugraptus, but they can be separated based on the characteristics of the cystidia and pileipellis. Pluteus multiformis is characterized by the scarce pleurocystidia, clavate cheilocystidia and caulocystidia and highly polymorphic elements of the pileipellis. Pluteus eludens is characterized mainly by utriform pleurocystidia. Pluteus eugraptus is known only with certainty from the type collection (Sri Lanka), which has been re-examined here, and it is characterized by narrowly lageniform pleurocystidia. Phylogenetic analyses based on ITS region sequence data supported the separation of P. multiformis, P. eludens and an additional collection from Japan that likely represents the true P. eugraptus. 相似文献