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91.
Gino Giannaccini Claudia Martini Antonio Lucacchini Enrica Strettoi Marco Piccolino† 《Journal of neurochemistry》1993,61(4):1263-1269
Abstract: The binding of [3 H]flunitrazepam, [3 H]RO 5-4864, and [3 H]PK 11195 to membrane preparations of the retina was studied in the turtle and rabbit. Only a single population of [3 H]flunitrazepam binding sites was detected in the turtle, whereas two populations appeared to be present in the rabbit. No specific binding for [3 H]RO 5-4864 and [3 H]PK 11195 could be detected in the turtle. In rabbit, both ligands bound with high affinity, revealing a significant population of binding sites (KD values of 24 ± 2.3 and 2.2 ± 0.8 nM, and Bmax values of 440 ± 35 and 1,482 ± 110 fmol/mg of protein, respectively). The binding was temperature - and protein-dependent. Displacement studies showed a similar rank order of potency of various unlabeled ligands against both [3 H]RO 5-4864 and [3 H]PK 11195 (PK 11195 > Ro 5-4864 > flunitrazepam > flumazenil). These results suggest that peripheral-type benzodiazepine receptors are present in the retina of the rabbit, but not of the turtle. 相似文献
92.
Marco A. Marra Shiv S. Prasad David L. Baillie 《Molecular & general genetics : MGG》1993,236(2-3):289-298
Summary A previous study of genomic organization described the identification of nine potential coding regions in 150 kb of genomic DNA from the unc-22(IV) region of Caenorhabditis elegans. In this study, we focus on the genomic organization of a small interval of 0.1 map unit bordered on the right by unc-22 and on the left by the left-hand breakpoints of the deficiencies sDf9, sDf19 and sDf65. This small interval at present contains a single mutagenically defined locus, the essential gene let-56. The cosmid C11F2 has previously been used to rescue let-56. Therefore, at least some of C11F2 must reside in the interval. In this paper, we report the characterization of two coding elements that reside on C11F2. Analysis of nucleotide sequence data obtained from cDNAs and cosmid subclones revealed that one of the coding elements closely resembles aromatic amino acid decarboxylases from several species. The other of these coding elements was found to closely resemble a human growth factor activatable Na+/H+ antiporter. Pairs of oligonucleotide primers, predicted from both coding elements, have been used in PCR experiments to position these coding elements between the left breakpoint of sDf19 and the left breakpoint of sDf65, between the essential genes let-653 and let-56. 相似文献
93.
Massimo Maffei Marco Mucciarelli Silvano Scannerini 《Biochemical Systematics and Ecology》1993,21(8):765-784
The effect of some environmental factors on the lipid metabolism was studied in two chemotypes of Rosmarinus officinalis L. Epicuticular hydrocarbons (EH), epicuticular fatty acids (EFA), whole leaf fatty acids (WLFA) and essential oils (EO) were extracted and analysed by GC-MS during winter 1991–1992 and related to temperature and moisture variations. Leaf fresh and dry wts were determined along with some morphophysiological parameters such as specific leaf weight (SLW) and specific leaf area (SLA). Leaf areas were calculated by image analysis and statistically processed as for chemical data. The results indicated that in R. officinalis the response to some environmental factors, with particular reference to temperature and moisture, was an increase in epicuticular hydrocarbons and a decrease in epicuticular fatty acids, leaf fatty acids and essential oils. Qualitative changes in the chemical composition of the above lipid classes were found to be correlated with temperature changes. From a chemosystematic viewpoint, a clear separation between the two chemotypes was achieved only when epicuticular hydrocarbons and essential oils were considered as chemosystematic characters. 相似文献
94.
Marco Patacca Marcus Lindner Manuel Esteban Lucas-Borja Thomas Cordonnier Gal Fidej Barry Gardiner Ylva Hauf Gediminas Jasinevičius Sophie Labonne Edgaras Linkevičius Mats Mahnken Slobodan Milanovic Gert-Jan Nabuurs Thomas A. Nagel Laura Nikinmaa Momchil Panyatov Roman Bercak Rupert Seidl Masa Zorana Ostrogović Sever Jaroslaw Socha Dominik Thom Dijana Vuletic Sergey Zudin Mart-Jan Schelhaas 《Global Change Biology》2023,29(5):1359-1376
Over the last decades, the natural disturbance is increasingly putting pressure on European forests. Shifts in disturbance regimes may compromise forest functioning and the continuous provisioning of ecosystem services to society, including their climate change mitigation potential. Although forests are central to many European policies, we lack the long-term empirical data needed for thoroughly understanding disturbance dynamics, modeling them, and developing adaptive management strategies. Here, we present a unique database of >170,000 records of ground-based natural disturbance observations in European forests from 1950 to 2019. Reported data confirm a significant increase in forest disturbance in 34 European countries, causing on an average of 43.8 million m3 of disturbed timber volume per year over the 70-year study period. This value is likely a conservative estimate due to under-reporting, especially of small-scale disturbances. We used machine learning techniques for assessing the magnitude of unreported disturbances, which are estimated to be between 8.6 and 18.3 million m3/year. In the last 20 years, disturbances on average accounted for 16% of the mean annual harvest in Europe. Wind was the most important disturbance agent over the study period (46% of total damage), followed by fire (24%) and bark beetles (17%). Bark beetle disturbance doubled its share of the total damage in the last 20 years. Forest disturbances can profoundly impact ecosystem services (e.g., climate change mitigation), affect regional forest resource provisioning and consequently disrupt long-term management planning objectives and timber markets. We conclude that adaptation to changing disturbance regimes must be placed at the core of the European forest management and policy debate. Furthermore, a coherent and homogeneous monitoring system of natural disturbances is urgently needed in Europe, to better observe and respond to the ongoing changes in forest disturbance regimes. 相似文献
95.
Davide Barberis Giampiero Lombardi Simone Ravetto Enri Marco Pittarello Davide Viglietti Michele Freppaz Michele Lonati 《Restoration Ecology》2023,31(1):e13777
Machine grading is frequently required to prepare the terrain when building high-altitude ski slopes in the Alps. However, this kind of disturbance alters the natural environment, destroying the vegetation and hampering its reestablishment. Thus, specific restoration plans are necessary to encourage the recovery of vegetation, which is already affected by different natural constraints in this harsh environment. One of the main critical factors affecting plant growth in high-altitude areas is the lack of available nitrogen (N) in the soil. In this context, the addition of a slow-release N fertilizer was carried out in an experimental revegetated ski slope between 2,800 and 2,900 m above sea level in the western Italian Alps. Both vegetation and soil were monitored during a 5-year period in order to test the effectiveness of N addition on the restoration process. Even if effects on soil carbon and N contents were negligible, vegetation was remarkably affected by the fertilization, since the total vegetation cover and the species richness significantly increased. Against the expectations, there was a remarkable increase in spontaneous forbs, rather than in most of the sown graminoids, which slightly varied during the experimental period. Actually, graminoids responded in different ways, mostly increasing (likewise forbs), but the slight decrease of the dominant Festuca nigrescens (Chewing's Fescue) masked their spread. This study confirms the noteworthy role of N in high-altitude alpine soils and consequently its importance to improve the restoration process of degraded ecosystems. 相似文献
96.
97.
Tamara Schmey Corinn Small Severin Einspanier Lina Muñoz Hoyoz Tahir Ali Soledad Gamboa Betty Mamani German C. Sepulveda Marco Thines Remco Stam 《Environmental microbiology》2023,25(10):1830-1846
The wild relatives of modern tomato crops are native to South America. These plants occur in habitats as different as the Andes and the Atacama Desert and are, to some degree, all susceptible to fungal pathogens of the genus Alternaria. Alternaria is a large genus. On tomatoes, several species cause early blight, leaf spots and other diseases. We collected Alternaria-like infection lesions from the leaves of eight wild tomato species from Chile and Peru. Using molecular barcoding markers, we characterized the pathogens. The infection lesions were caused predominantly by small-spored species of Alternaria of the section Alternaria, like A. alternata, but also by Stemphylium spp., Alternaria spp. from the section Ulocladioides and other related species. Morphological observations and an infection assay confirmed this. Comparative genetic diversity analyses show a larger diversity in this wild system than in studies of cultivated Solanum species. As A. alternata has been reported to be an increasing problem in cultivated tomatoes, investigating the evolutionary potential of this pathogen is not only interesting to scientists studying wild plant pathosystems. It could also inform crop protection and breeding programs to be aware of potential epidemics caused by species still confined to South America. 相似文献
98.
We studied the effect of heparin on proliferation and signalling in normal NIH/3T3 fibroblasts, and in cells transformed by different oncogenes. Heparin inhibited the proliferation of normal as well as of v-sis and v-erbB transformed fibroblasts in the presence of serum, but failed to inhibit v-erbB-driven proliferation in serum-starved cultures; under these conditions, heparin inhibited by approximately 50% the proliferation of normal and v-sis- transformed cells. Heparin also inhibited PDGF-induced cell proliferation and inositol lipid turnover in v-sis transformants, but it did not affect PDGF mitogenic signalling in NIH/3T3 fibroblasts. 相似文献
99.
Laetitia Mathon Virginie Marques Stéphanie Manel Camille Albouy Marco Andrello Emilie Boulanger Julie Deter Régis Hocdé Fabien Leprieur Tom B. Letessier Nicolas Loiseau Eva Maire Alice Valentini Laurent Vigliola Florian Baletaud Sandra Bessudo Tony Dejean Nadia Faure Pierre-Edouard Guerin Meret Jucker Jean-Baptiste Juhel Kadarusman Andrea Polanco F. Laurent Pouyaud Dario Schwörer Kirsten F. Thompson Marc Troussellier Hagi Yulia Sugeha Laure Velez Xiaowei Zhang Wenjun Zhong Loïc Pellissier David Mouillot 《Global Ecology and Biogeography》2023,32(8):1336-1352
Aim
Coastal fishes have a fundamental role in marine ecosystem functioning and contributions to people, but face increasing threats due to climate change, habitat degradation and overexploitation. The extent to which human pressures are impacting coastal fish biodiversity in comparison with geographic and environmental factors at large spatial scale is still under scrutiny. Here, we took advantage of environmental DNA (eDNA) metabarcoding to investigate the relationship between fish biodiversity, including taxonomic and genetic components, and environmental but also socio-economic factors.Location
Tropical, temperate and polar coastal areas.Time period
Present day.Major taxa studied
Marine fishes.Methods
We analysed fish eDNA in 263 stations (samples) in 68 sites distributed across polar, temperate and tropical regions. We modelled the effect of environmental, geographic and socio-economic factors on α- and β-diversity. We then computed the partial effect of each factor on several fish biodiversity components using taxonomic molecular units (MOTU) and genetic sequences. We also investigated the relationship between fish genetic α- and β-diversity measured from our barcodes, and phylogenetic but also functional diversity.Results
We show that fish eDNA MOTU and sequence α- and β-diversity have the strongest correlation with environmental factors on coastal ecosystems worldwide. However, our models also reveal a negative correlation between biodiversity and human dependence on marine ecosystems. In areas with high dependence, diversity of all fish, cryptobenthic fish and large fish MOTUs declined steeply. Finally, we show that a sequence diversity index, accounting for genetic distance between pairs of MOTUs, within and between communities, is a reliable proxy of phylogenetic and functional diversity.Main conclusions
Together, our results demonstrate that short eDNA sequences can be used to assess climate and direct human impacts on marine biodiversity at large scale in the Anthropocene and can further be extended to investigate biodiversity in its phylogenetic and functional dimensions. 相似文献100.