451,078 research outputs found
Seven connection patterns between the author research areas.
No full textSeven connection patterns between the author research areas.</p
Subcellular nutrient element localization and enrichment in ecto- and arbuscular mycorrhizas of field-grown beech and ash trees indicate functional differences.
No full textMycorrhizas are the chief organ for plant mineral nutrient acquisition. In temperate, mixed forests, ash roots (Fraxinus excelsior) are colonized by arbuscular mycorrhizal fungi (AM) and beech roots (Fagus sylvatica) by ectomycorrhizal fungi (EcM). Knowledge on the functions of different mycorrhizal species that coexist in the same environment is scarce. The concentrations of nutrient elements in plant and fungal cells can inform on nutrient accessibility and interspecific differences of mycorrhizal life forms. Here, we hypothesized that mycorrhizal fungal species exhibit interspecific differences in mineral nutrient concentrations and that the differences correlate with the mineral nutrient concentrations of their associated root cells. Abundant mycorrhizal fungal species of mature beech and ash trees in a long-term undisturbed forest ecosystem were the EcM Lactarius subdulcis, Clavulina cristata and Cenococcum geophilum and the AM Glomus sp. Mineral nutrient subcellular localization and quantities of the mycorrhizas were analysed after non-aqueous sample preparation by electron dispersive X-ray transmission electron microscopy. Cenococcum geophilum contained the highest sulphur, Clavulina cristata the highest calcium levels, and Glomus, in which cations and P were generally high, exhibited the highest potassium levels. Lactarius subdulcis-associated root cells contained the highest phosphorus levels. The root cell concentrations of K, Mg and P were unrelated to those of the associated fungal structures, whereas S and Ca showed significant correlations between fungal and plant concentrations of those elements. Our results support profound interspecific differences for mineral nutrient acquisition among mycorrhizas formed by different fungal taxa. The lack of correlation between some plant and fungal nutrient element concentrations may reflect different retention of mineral nutrients in the fungal part of the symbiosis. High mineral concentrations, especially of potassium, in Glomus sp. suggest that the well-known influence of tree species on chemical soil properties may be related to their mycorrhizal associates
Seabed foraging by Antarctic krill: Implications for stock assessment, bentho-pelagic coupling, and the vertical transfer of iron
No full textA compilation of more than 30 studies shows that adult Antarctic krill (Euphausia superba) may frequent benthic habitats year-round, in shelf as well as oceanic waters and throughout their circumpolar range. Net and acoustic data from the Scotia Sea show that in summer 2-20% of the population reside at depths between 200 and 2000 m, and that large aggregations can form above the seabed. Local differences in the vertical distribution of krill indicate that reduced feeding success in surface waters, either due to predator encounter or food shortage, might initiate such deep migrations and results in benthic feeding. Fatty acid and microscopic analyses of stomach content confirm two different foraging habitats for Antarctic krill: the upper ocean, where fresh phytoplankton is the main food source, and deeper water or the seabed, where detritus and copepods are consumed. Krill caught in upper waters retain signals of benthic feeding, suggesting frequent and dynamic exchange between surface and seabed. Krill contained up to 260 nmol iron per stomach when returning from seabed feeding. About 5% of this iron is labile, i.e., potentially available to phytoplankton. Due to their large biomass, frequent benthic feeding, and acidic digestion of particulate iron, krill might facilitate an input of new iron to Southern Ocean surface waters. Deep migrations and foraging at the seabed are significant parts of krill ecology, and the vertical fluxes involved in this behavior are important for the coupling of benthic and pelagic food webs and their elemental repositories
Seven-day food consumption score (FCS) of the mothers.
No full textSeven-day food consumption score (FCS) of the mothers.</p
Seven-day case rates of Tübingen and control group.
No full textSeven-day case rates of Tübingen and control group.</p
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Transcription: Traditional story about the Seven Sons
No full textTranscription of a retelling of Chaa paa tkhiiu ki paomin (the Story of Seven Sons), as told by Angtoi Sankhil. A man is killed by a tiger, and as his six sons go to avenge him, he kills them too one by one. The mother is pregnant with a seventh son, who is able to foretell events while still in the womb. After the child learns how his father died, he goes to confront the tiger and his wife. He avoids the tiger's attempt to kill him, takes back his father's head from the tiger's possession, and vanquishes the tiger
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Seven-day case rates for alternative predictor sets and donor pools.
No full textSeven-day case rates for alternative predictor sets and donor pools.</p
HAT-P-58b -- HAT-P-64b: Seven Planets Transiting Bright Stars
No full textWe report the discovery and characterization of 7 transiting exoplanets from the HATNet survey. The planets, which are hot Jupiters and Saturns transiting bright sun-like stars, include: HAT-P-58b (with mass M_p = 0.37 M_J, radius R_p = 1.33 R_J, and orbital period P = 4.0138 days), HAT-P-59b (M_p = 1.54 M_J, R_p = 1.12 R_J, P = 4.1420 days), HAT-P-60b (M_p = 0.57 M_J, R_p = 1.63 R_J, P = 4.7948 days), HAT-P-61b (M_p = 1.06 M_J, R_p = 0.90 R_J, P = 1.9023 days), HAT-P-62b (M_p = 0.76 M_J, R_p = 1.07 R_J, P = 2.6453 days), HAT-P-63b (M_p = 0.61 M_J, R_p = 1.12 R_J, P = 3.3777 days), and HAT-P-64b (M_p = 0.58 M_J, R_p = 1.70 R_J, P = 4.0072 days). The typical errors on these quantities are 0.06 M_J, 0.03 R_J, and 0.2 seconds, respectively. We also provide accurate stellar parameters for each of the hosts stars. With V = 9.710±0.050mag, HAT-P-60 is an especially bright transiting planet host, and an excellent target for additional follow-up observations. With Rp = 1.703±0.070 R_J, HAT-P-64b is a highly inflated hot Jupiter around a star nearing the end of its main-sequence lifetime, and is among the largest known planets. Five of the seven systems have long-cadence observations by TESS which are included in the analysis. Of particular note is HAT-P-59 (TOI-1826.01) which is within the Northern continuous viewing zone of the TESS mission, and HAT-P-60, which is the TESS candidate TOI-1580.01
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