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991.
Nathan F. Putman Eugenia Naro-Maciel 《Proceedings. Biological sciences / The Royal Society》2013,280(1768)
Organismal movement is an essential component of ecological processes and connectivity among ecosystems. However, estimating connectivity and identifying corridors of movement are challenging in oceanic organisms such as young turtles that disperse into the open sea and remain largely unobserved during a period known as ‘the lost years’. Using predictions of transport within an ocean circulation model and data from published genetic analysis, we present to our knowledge, the first basin-scale hypothesis of distribution and connectivity among major rookeries and foraging grounds (FGs) of green turtles (Chelonia mydas) during their ‘lost years’. Simulations indicate that transatlantic dispersal is likely to be common and that recurrent connectivity between the southwestern Indian Ocean and the South Atlantic is possible. The predicted distribution of pelagic juvenile turtles suggests that many ‘lost years hotspots’ are presently unstudied and located outside protected areas. These models, therefore, provide new information on possible dispersal pathways that link nesting beaches with FGs. These pathways may be of exceptional conservation concern owing to their importance for sea turtles during a critical developmental period. 相似文献
992.
Eugenia Martin Vanina Cravero Ezio Portis Davide Scaglione Esteban Acquaviva Enrique Cointry 《Molecular breeding : new strategies in plant improvement》2013,32(1):177-187
An F1 mapping population was bred by crossing an accession of wild cardoon with a single Argentinian globe artichoke plant of the variety Estrella del Sur FCA with a view to generating new Cynara cardunculus linkage maps. Genotyping was conducting using a set of 553 SRAP, SSR, AFLP and SNP markers. The 1,465.5 cM map based on the segregation of alleles present in the wild cardoon parent comprised 214 loci distributed across 16 linkage groups (LGs), while the 910.1 cM globe artichoke-based map featured 141 loci falling into 12 LGs covering the total length. Three of the morphological traits (head spininess, leaf spininess and head color) for which the parents contrasted were inherited monogenically, and the genes conditioning them were mapped. A set of 48 co-dominant loci was used to align the LGs with those derived from a reference SSR-based consensus map of the species. 相似文献
993.
María?Eugenia?FerreroEmail author Ricardo?Villalba Mónica?De?Membiela Alberto?Ripalta Silvia?Delgado Leonardo?Paolini 《Plant Ecology》2013,214(11):1321-1334
Subtropical forests in montane ecosystems grow under a wide range of environmental conditions. However, little is known about the growth responses of subtropical trees to climate along ecological gradients. To assess how, and to what extent climate controls tree growth, we analyzed tree responses to climate for 15 chronologies from 4 different species (Schinopsis lorentzii, Juglans australis, Cedrela lilloi, Alnus acuminata) across a variety of environments in subtropical forests from northwestern Argentina (22–28°S, 64–66°W). Using correlation and principal component analysis, site and species differences in tree-growth responses to precipitation and temperature were determined along the elevation gradient from the dry-warm Chaco lowlands to the wet-cool montane Yungas. Our results show that species responses differ according to the severity in climate conditions along the elevation gradient. At sites with unfavorable conditions, mainly located at the extremes of the environmental gradient, responses of different species to climate variations are similar; in contrast, at sites with relatively mild conditions, tree growth displays a large variety of responses reflecting differences in both local environmental conditions and species physiology. Our research suggests that individualistic responses to environmental variability would determine differences in the type and timing of the responses of dominant trees to climate, which ultimately may shift species’ assemblages in montane subtropical regions of South America under future climate changes. 相似文献
994.
Kim CS Epand RF Leikina E Epand RM Chernomordik LV 《The Journal of biological chemistry》2011,286(15):13226-13234
One of the best characterized fusion proteins, the influenza virus hemagglutinin (HA), mediates fusion between the viral envelope and the endosomal membrane during viral entry into the cell. In the initial conformation of HA, its fusogenic subunit, the transmembrane protein HA2, is locked in a metastable conformation by the receptor-binding HA1 subunit of HA. Acidification in the endosome triggers HA2 refolding toward the final lowest energy conformation. Is the fusion process driven by this final conformation or, as often suggested, by the energy released by protein restructuring? Here we explored structural properties as well as the fusogenic activity of the full sized trimeric HA2(1–185) (here called HA2*) that presents the final conformation of the HA2 ectodomain. We found HA2* to mediate fusion between lipid bilayers and between biological membranes in a low pH-dependent manner. Two mutations known to inhibit HA-mediated fusion strongly inhibited the fusogenic activity of HA2*. At surface densities similar to those of HA in the influenza virus particle, HA2* formed small fusion pores but did not expand them. Our results confirm that the HA1 subunit responsible for receptor binding as well as the transmembrane and cytosolic domains of HA2 is not required for fusion pore opening and substantiate the hypothesis that the final form of HA2 is more important for fusion than the conformational change that generates this form. 相似文献
995.
Gonzalez LE Kotler ML Vattino LG Conti E Reisin RC Mulatz KJ Snutch TP Uchitel OD 《Journal of neurochemistry》2011,119(4):826-838
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by a gradual loss of motoneurons. The majority of ALS cases are associated with a sporadic form whose etiology is unknown. Several pieces of evidence favor autoimmunity as a potential contributor to sporadic ALS pathology. To gain understanding concerning possible antigens interacting with IgGs from sporadic ALS patients (ALS-IgGs), we studied immunoreactivity against neuromuscular junction (NMJ), spinal cord and cerebellum of mice with and without the Ca(V) 2.1 pore-forming subunit of the P/Q-type voltage-gated calcium (Ca(2+)) channel. ALS-IgGs showed a strong reactivity against NMJs of wild-type diaphragms. ALS-IgGs also increased muscle miniature end-plate potential frequency, suggesting a functional role for ALS-IgGs on synaptic signaling. In support, in mice lacking the Ca(V) 2.1 subunit ALS-IgGs showed significantly reduced NMJ immunoreactivity and did not alter spontaneous acetylcholine release. This difference in reactivity was absent when comparing N-type Ca(2+) channel wild-type or null mice. These results are particularly relevant because motoneurons are known to be early pathogenic targets in ALS. Our findings add further evidence supporting autoimmunity as one of the possible mechanisms contributing to ALS pathology. They also suggest that serum autoantibodies in a subset of ALS patients would interact with NMJ proteins down-regulated when P/Q-type channels are absent. 相似文献
996.
997.
Riccio ME Nunes JM Rahal M Kervaire B Tiercy JM Sanchez-Mazas A 《Human biology; an international record of research》2011,83(3):405-435
The Austroasiatic linguistic family disputes its origin between two geographically distant regions of Asia, India, and Southeast Asia, respectively. As genetic studies based on classical and gender-specific genetic markers provided contradictory results to this debate thus far, we investigated the HLA diversity (HLA-A, -B, and -DRB1 loci) of an Austroasiatic Munda population from Northeast India and its relationships with other populations from India and Southeast Asia. Because molecular methods currently used to test HLA markers often provide ambiguous results due to the high complexity of this polymorphism, we applied two different techniques (reverse PCR-SSO typing on microbeads arrays based on Luminex technology, and PCR-SSP typing) to type the samples. After validating the resulting frequency distributions through the original statistical method described in our companion article ( Nunes et al. 2011 ), we compared the HLA genetic profile of the sampled Munda to those of other Asiatic populations, among which Dravidian and Indo-European-speakers from India and populations from East and Southeast Asia speaking languages belonging to different linguistic families. We showed that the Munda from Northeast India exhibit a peculiar genetic profile with a reduced level of HLA diversity compared to surrounding Indian populations. They also exhibit less diversity than Southeast Asian populations except at locus DRB1. Several analyses using genetic distances indicate that the Munda are much more closely related to populations from the Indian subcontinent than to Southeast Asian populations speaking languages of the same Austroasiatic linguistic family. On the other hand, they do not share a closer relationship with Dravidians compared with Indo-Europeans, thus arguing against the idea that the Munda share a common and ancient Indian origin with Dravidians. Our results do not favor either a scenario where the Munda would be representative of an ancestral Austroasiatic population giving rise to an eastward Austroasiatic expansion to Southeast Asia. Rather, their peculiar genetic profile is better explained by a decrease in genetic diversity through genetic drift from an ancestral population having a genetic profile similar to present-day Austroasiatic populations from Southeast Asia (thus suggesting a possible southeastern origin), followed by intensive gene flow with neighboring Indian populations. This conclusion is in agreement with archaeological and linguistic information. The history of the Austroasiatic family represents a fascinating example where complex interactions among culturally distinct human populations occurred in the past. 相似文献
998.
Konstantis F. Konidaris Eugenia Katsoulakou Vassilis Psycharis Theocharis C. Stamatatos Evy Manessi-Zoupa 《Inorganica chimica acta》2011,376(1):470-478
The first employment of pyridine-2-amidoxime [(py)C(NH2)NOH] in zinc(II) chemistry is reported. The syntheses, crystal structures, and spectroscopic characterization are described for complexes [Zn(O2CR)2{(py)C(NH2)NOH}2] (R = Me; 1, Ph; 2), [Zn2(acac)2{(py)C(NH2)NO}2] (3), and [Zn(NO3){(py)C(NH2)NOH}2](NO3) (4). The reactions between Zn(O2CR)2·2H2O (R = Me, Ph) or Zn(NO3)2·5H2O and two equivalents of (py)C(NH2)NOH in MeOH led to mononuclear compounds 1, 2 and 4, respectively. All three complexes contain two neutral N,N′-chelating (η2) (py)C(NH2)NOH ligands, coordinated through the Npyridyl and Noxime atoms. In contrast, the use of Zn(acac)2·H2O in place of Zn(O2CR)2·2H2O gives the dinuclear compound 3, which instead contains the anionic, η1:η1:η1:μ bridging form of the organic ligand; the ZnII atoms are doubly bridged by the diatomic oximate groups of the (py)C(NH2)NO− groups. Strong intra- and intermolecular hydrogen bonding interactions provide appreciable thermodynamic stability and interesting supramolecular chemistry for compounds 1-4. The photoluminescence properties of complexes 1-4 recorded in the solid state at room temperature are also presented. 相似文献
999.
1000.
Wróblewska J Sekowska A Zalas-Wiecek P Gospodarek E 《Medycyna do?wiadczalna i mikrobiologia》2011,63(2):99-103
A total of 103 isolates of CNS (66 strains of S. epidermidis and 37 strains of S. haemolyticus) were investigated. Lipolytic activity of staphylococcal strains was determined by Tryptic Soy Agar containing Tween 20 or Tween 60. The 95.4% strains of staphylococci demonstrated the lipolytic activity on Tween 20 agar and the 89.4% of strains of staphylococci degradation ester of fatty acids on Tweens 60 agar. We detected that S. epidermidis strains (respectively 95,4%, 89,4%) produced lipases more frequently than S. haemolyticus strains (respectively 72,9%, 59,4%). Studies suggest that source of isolation from clinical materials (blood, wound and pus) does not have an influence on the ability hydrolysis esters. 相似文献