100,481 research outputs found
A single-station model suitable for f0F2 mapping
No full textIonospheric monthly-median values of the F2 and E layer critical frequencies from 24 mid-latitude European stations are fitted to a second degree polynomial and their correlation is discussed. The resulting model is used to predict monthly-median f0F2 values for different ionospheric stations and for high, medium and low ionospheric activity. Finally, a potential application of the single station model developed for Slough to mapping the F2-layer critical frequency is investigated. Thus prediction of the monthly median f0F2 values for eight mid-latitude European stations is attempted using the single-station model of Slough and the corresponding F0E values of the station under investigation. The f0F2 values obtained are reasonably accurate. The main advantage of this method is its simplicity and the restricted number of parameters used.JCR Journalope
The mitochondrial genome of one ‘twisted-wing parasite’ Xenos cf. moutoni (Insecta, Strepsiptera, Xenidae) from Gaoligong Mountains, Southwest of China
No full textThe nearly complete mitochondrial genome (mitogenome) of Xenos cf. moutoni, one twisted-wing parasite on wasp Vespa velutina from Southwest of China, is described in this study. The total length of this mitogenome is 16,717 bp, containing 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs) and an incomplete A + T-rich control region . All of the 13 PCGs are initiated with canonical ATN (N represents A, T, G, C) as start codons; 8 PCGs are terminated with a complete typical stop codon TAA, and the remaining five PCGs (cox2, cox3, nad3, nad4 and nad5) have an incomplete stop codon with just a T. The phylogenetic analysis based on the nucleotide sequences of PCGs and rRNAs indicates that Xenos cf. moutoni has a close relationship with Xenos vesparum, confirming its placement in the family Xenidae
The effects of f0 F2 variability on TEC prediction accuracy
No full textIn this paper hourly daily F2-layer critical frequency data recorded at Rome and one minute daily TEC data recorded at Florence were used and the relevant variabiles were calculated. It was concluded that there was no clear evidence as to how they correlated. In order to obtain a measure of the f 0 F 2 and TEC variability, the normalised differences df0 F2 and d TEC from the relevant monthly median values were also considered. Since no clear evidence could be obtained as of how df0 F2 and d TEC correlate, a new parameter, the ?Ap /?R ratio was tried. ?Ap was taken as the difference between the maximum value of Ap measured at the relevant disturbance and that corresponding at the beginning of the disturbance. ?R corresponded to the two above mentioned values of Ap. This parameter was compared to the differences of the corresponding df0 F2 values called ?df and d TEC values called ?dT. In wintertime, when ?A p /? R was negative, for the vast majority of the occurrences either ?df or ?dT was negative; ?df and ?dT were never observed to be negative at the same time whereas they were both positive in fewer than 10% of the observations. When ?A p /?R was positive then either ?df or ?dT were negative. In summertime when ?A p /?R was negative both ?df and ?dT were negative. When ?A p /?R was positive, while a positive ?df corresponded almost always to a positive ?dT, a negative ?df would equiprobably indicate either a positive or a negative ?dT.PublishedJCR Journalope
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
A multiple receiver - multiple transmitter VLF high-order differential analysis evaluation network for near real-time detection and discrimination of seismic-ionospheric precursor phenomena
No full textApplication of differential analysis of VLF signals for seismic-ionospheric precursor detection from multiple receivers
No full textHandwritten biographical information on Paulina T. McClung Merritt
No full textA handwritten biography of Paulina T. McClung Merritt by an unknown author, 1892.
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
No full textIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Ten years analysis of Tropospheric refractivity variations
No full textThe refractivity variations of the troposphere are responsible for various effects on radio wave propagation, such as refraction, bending, radio-station interference, etc. In this work, the refractivity variations of the Hellenic
troposphere are studied using data from Helliniko airport of Athens/Greece. The data were analyzed using various interpolation procedures, i.e. in a day-by-day manner for temperature and relative humidity, to transform the data according to a reference height common for the whole dataset and finally for the refractivity
N with respect to time, using piece-wise hermite interpolation polynomials for the low and medium altitudes and linear interpolation factors for the high altitudes. Since refractivity varies with time and height, two height independent basic parameters were computed and analyzed: the refractivity at station height N0 and scale height Hs. These parameters can be used to calculate the refractivity profile. Using statistical tools as the moving average, the ß0 parameter and the monthly mean values, together with the corresponding standard deviations, useful results were obtained for the variations of the refractivity with respect to observation hour, height, season, month, day and level.PublishedJCR Journalope
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