58,777 research outputs found
Disruption of the developmental programme of Trypanosoma brucei by genetic ablation of TbZFP1, a differentiation-enriched CCCH protein
No full textThe regulation of differentiation is particularly important in microbial eukaryotes that inhabit multiple environments. The parasite Trypanosoma brucei is an extreme example of this, requiring exquisite gene regulation during transmission from mammals to the tsetse fly vector. Unusually, trypanosomes rely almost exclusively on post-transcriptional mechanisms for regulated gene expression. Hence, RNA binding proteins are potentially of great significance in controlling stage-regulated processes. We have previously identified TbZFP1 as a trypanosome molecule transiently enriched during differentiation to tsetse midgut procyclic forms. This small protein (101 amino acids) contains the unusual CCCH zinc finger, an RNA binding motif. Here, we show that genetic ablation of TbZFP1 compromises repositioning of the mitochondrial genome, a specific event in the strictly regulated differentiation programme. Despite this, other events that occur both before and after this remain intact. Significantly, this phenotype correlates with the TbZFP1 expression profile during differentiation. This is the first genetic disruption of a developmental regulator in T. brucei. It demonstrates that programmed events in parasite development can be uncoupled at the molecular level. It also further supports the importance of CCCH proteins in key aspects of trypanosome cell function
Miscellaneous -- Jan.-June 1950 -- Correspondence, Toxoplasmosis -- letter, 1950-04-07
No full textLetter from Matthews, A. R. K. to Sabin, Albert B. dated 1950-04-07.Sabin Collection Fair Use Policy</a
[Jenny Matthews, Clifford B. Jones and R. C. Goodwin, 1966]
No full textPhotograph of three people taken on May 23, 1966. The accompanying press release states "PRESIDENT HONORED--Tech President Dr. R. C. Goodwin, was presented Tech Association of Women Students' Man of Distinction Award in surprise ceremonies Monday. AWS president Jenny Matthews of Andrews cited Dr. Goodwin's "many contributions to Tech" in making the award which also carries honorary membership in the student organization. Former Tech president Dr. Clifford B. Jones (left) is the only other male honorary member of AWS."
Letter from Arno B. Cammerer to J. R. Eakin
No full textLetter from Arno B. Cammerer to J. R. Eakin describing the procedure for purchasing Bright Angel Trail
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
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
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
Pelochrista wrighti Gilligan & Matthews & Miller 2018, sp.n.
No full text<i>Pelochrista wrighti</i> Gilligan and Matthews, sp.n. (Figs. 4–6, 8) <p> <b>Diagnosis</b>. The distinctive male genitalia place <i>P. wrighti</i> in <i>Pelochrista</i> in the <i>canana</i> group (species 78–87 in Wright and Gilligan 2015). <i>Pelochrista wrighti</i> can be separated from all other members of the group by the lack of a welldefined ocellus and the white and brown fasciate pattern on the forewing.</p> <p> <b>Description</b>. <b>Male</b> (Figs. 4-6, 8). <i>Head</i>: Frons white; vertex white with mix of brown scales laterally; labial palpus length ca. 1.25 × horizontal diameter of compound eye, first two segments light pale brown dorsolaterally, white ventrally, third segment solid brown; antenna light pale brown; scape white. <i>Thorax</i>: Dorsal surface and tegula white with mottled patches of brown and light brown; pro- and mesothoracic legs brown, metathoracic leg pale brown to white, tarsi with white annulations. Forewing (Figs. 4–6) length 6.5–7.6 mm (mean 7.1 mm; n = 3), AR = 2.74; costal fold present along basal 1/3 of costa; ground color brown; wing markings white and brown; costal strigulae strongly expressed distad of costal fold (pairs 3–9); subbasal fascia dark brown, continuous from dorsum to radius; striae associated with costal strigulae pairs 5–6 dislocated distally and confluent with stria 7, separating the median and postmedian fasciae into narrow bands and a conspicuous dark brown pretornal patch; postmedian band and preterminal fascia indistinct patches or bands; ocellus absent. Hindwing brown, fringe scales brown basally, pale grayish brown apically. <i>Abdomen</i>: Genitalia (n = 2) (Fig. 8) with uncus evenly rounded, densely setose, weakly differentiated from dorsolateral shoulders of tegumen; socii long, densely setose, narrowed distally; phallus relatively long, tapering gradually, with base loosely surrounded by anellus; vesica with 9–10 deciduous cornuti; valva with costal margin weakly concave to nearly straight, ventral emargination moderate, NR = 0.35, saccular corner acute, mean SA = 76°; valval neck with subcostal line of hairlike setae; cucullus with dorsal lobe weakly developed and rounded, ventral lobe triangular, anal spine stout, medial surface covered in coarse setae.</p> <p> <b>Female</b>. Unknown.</p> <p> <b>Holotype</b> (Fig. 4). ♂, “ BAHAMAS: South Abaco, Schooner Bay Institute, vic. power substation, 26.167500°, - 77.18900°, 4.vi.2016, J. Miller, G. Goss, M. Simon, D. Matthews. Bahamas Survey, MGCL Accession # 2016-09. TMG 729 Genitalia dissection. MGCL 246573 McGuire Center for Lepidoptera & Biodiversity, FLMNH, UF [barcode]” MGCL.</p> <p> <b>Paratypes</b> (Figs. 5–6). BAHAMAS: N. Andros, Stafford Creek, Love at First Sight (Motel, at MVL), 24.901449°, - 77.936089°, 18 m, 28.x.2011, J. Y. Miller, M. Simon, G. Goss, D. Matthews. J. Y. Miller et al. Bahamas Survey MGCL Accession No. 2011-32. MGCL 233027 McGuire Center for Lepidoptera & Biodiversity, FLMNH, UF (1 ♂ MGCL); Grand Bahama Island, Freeport, Sea Gate Ln., 26.504418°, -78.650936°, 24.x.2014, J. Miller, M. Simon, R. Rozycki, D. Matthews. Bahamas Survey MGCL Accession No. 2014-31. D. Matthews Genitalia Prep. # 1806. MGCL 238166 McGuire Center for Lepidoptera & Biodiversity, FLMNH, UF (1 ♂ MGCL).</p> <p> <b>Etymology</b>. The species name is in honor of Donald J. Wright, whose tireless work on <i>Eucosma</i> and <i>Pelochrista</i> for the past 20 years has provided us with an understanding of these otherwise impossible groups.</p> <p> <b>Distribution and Biology</b>. This species has been recorded from three islands in the Bahamas, with adults captured in June and October. Larval hosts are unknown. Specimens were collected in or near relict or larger tracts of rocky pineland dominated by <i>Pinus caribaea</i>. The holotype was collected in a relatively pristine tract of pineland on the outskirts of a recent housing development.</p>Published as part of <i>Gilligan, Todd M., Matthews, Deborah L. & Miller, Jacqueline Y., 2018, Two new species of Eucosmini from the Bahamas (Lepidoptera: Tortricidae), pp. 265-268 in Zootaxa 4378 (2)</i> on pages 266-268, DOI: 10.11646/zootaxa.4378.2.5, <a href="http://zenodo.org/record/1169523">http://zenodo.org/record/1169523</a>
Branching fraction and CP asymmetry of the decays B+→K0Sπ+ and B+→K0SK+
No full textAn analysis of B+ → K0
Sπ+ and B+ → K0
S K+ decays is performed with the LHCb experiment. The pp
collision data used correspond to integrated luminosities of 1 fb−1 and 2 fb−1 collected at centre-ofmass
energies of
√
s = 7 TeV and
√
s = 8 TeV, respectively. The ratio of branching fractions and the
direct CP asymmetries are measured to be B(B+ → K0
S K+
)/B(B+ → K0
Sπ+
) = 0.064 ± 0.009 (stat.) ±
0.004 (syst.), ACP(B+ → K0
Sπ+
) = −0.022 ± 0.025 (stat.) ± 0.010 (syst.) and ACP(B+ → K0
S K+
) =
−0.21 ± 0.14 (stat.) ± 0.01 (syst.). The data sample taken at
√
s = 7 TeV is used to search for
B+
c
→ K0
S K+ decays and results in the upper limit ( fc · B(B+
c
→ K0
S K+
))/( fu · B(B+ → K0
Sπ+
)) <
5.8 × 10−2 at 90% confidence level, where fc and fu denote the hadronisation fractions of a ¯b
quark
into a B+
c or a B+ meson, respectively
The developmental cell biology of Trypanosoma brucei
No full textTrypanosoma brucei provides an excellent system for studies of many aspects of cell biology, including cell structure and morphology, organelle positioning, cell division and protein trafficking. However, the trypanosome has a complex life cycle in which it must adapt either to the mammalian bloodstream or to different compartments within the tsetse fly. These differentiation events require stage-specific changes to basic cell biological processes and reflect responses to environmental stimuli and programmed differentiation events that must occur within a single cell. The organization of cell structure is fundamental to the trypanosome throughout its life cycle. Modulations of the overall cell morphology and positioning of the specialized mitochondrial genome, flagellum and associated basal body provide the classical descriptions of the different life cycle stages of the parasite. The dependency relationships that govern these morphological changes are now beginning to be understood and their molecular basis identified. The overall picture emerging is of a highly organized cell in which the rules established for cell division and morphogenesis in organisms such as yeast and mammalian cells do not necessarily apply. Therefore, understanding the developmental cell biology of the African trypanosome is providing insight into both fundamentally conserved and fundamentally different aspects of the organization of the eukaryotic cell
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