907 research outputs found
Spain and Portugal / engraved by the omnigraph F. P. Becker & Cº. ; Geo, Virtue
No full text1 mapa. Datat entre 1840 i 1849 aproximadament.22 x 27 c
Dystrophin quantification and clinical correlations in Becker muscular dystrophy: Implications for clinical trials
No full textDuchenne muscular dystrophy is caused by mutations in the DMD gene that disrupt the open reading frame and prevent the full translation of its protein product, dystrophin. Restoration of the open reading frame and dystrophin production can be achieved by exon skipping using antisense oligonucleotides targeted to splicing elements. This approach aims to transform the Duchenne muscular dystrophy phenotype to that of the milder disorder, Becker muscular dystrophy, typically caused by in-frame dystrophin deletions that allow the production of an internally deleted but partially functional dystrophin. There is ongoing debate regarding the functional properties of the different internally deleted dystrophins produced by exon skipping for different mutations; more insight would be valuable to improve and better predict the outcome of exon skipping clinical trials. To this end, we have characterized the clinical phenotype of 17 patients with Becker muscular dystrophy harbouring in-frame deletions relevant to on-going or planned exon skipping clinical trials for Duchenne muscular dystrophy and correlated it to the levels of dystrophin, and dystrophin-associated protein expression. The cohort of 17 patients, selected exclusively on the basis of their genotype, included 4 asymptomatic, 12 mild and 1 severe patient. All patients had dystrophin levels of >40 of control and significantly higher dystrophin (P=0.013), β-dystroglycan (P=0.025) and neuronal nitric oxide synthase (P=0.034) expression was observed in asymptomatic individuals versus symptomatic patients with Becker muscular dystrophy. Furthermore, grouping the patients by deletion, patients with Becker muscular dystrophy with deletions with an end-point of exon 51 (the skipping of which could rescue the largest group of Duchenne muscular dystrophy deletions) showed significantly higher dystrophin levels (P=0.034) than those with deletions ending with exon 53. This is the first quantitative study on both dystrophin and dystrophin-associated protein expression in patients with Becker muscular dystrophy with deletions relevant for on-going exon skipping trials in Duchenne muscular dystrophy. Taken together, our results indicate that all varieties of internally deleted dystrophin assessed in this study have the functional capability to provide a substantial clinical benefit to patients with Duchenne muscular dystrophy. © The Author (2011)
Beyond Lesson Studies and Design Experiments: Using theoretical tools in practice and finding out how they work
Get PDFThis paper aims to illustrate how fruitful insights into the link between school teaching practice and student learning outcomes can be theoretically grounded by the variation theory from the field of phenomenography; and from this framework demonstrate how a 'pedagogy of awareness' can be implemented in the classroom. In this study, five teachers and 162 students at Primary Four level of school education in Hong Kong participated and the practice of the 'learning study' was adopted. By comparing the results of pre- and posttests, a significant gain was observed in the students learning outcomes.
The problem of the Hungarian borders and minorities in British foreign political thought, 1938-41
No full textThis thesis analyses the British official attitudes and the gradual change of British policy towards Hungary and Hungarian revisionism in the period from the Anschluss in March 1938 to December 1941, when the British government declared war on Hungary. The primary focus of this thesis lies in the impact of Hungary`s territorial claims on British policy towards Hungary and Central Europe and upon the criteria Britain judged the territorial gains of Hungary between 1938 and 1941. This work is the result of the author`s research in British, American and Hungarian archives, along with his reflection on numerous documentary editions, diaries, memoirs and secondary sources. It aims to deepen our knowledge of Anglo-Hungarian relationship, British Central European policy and the British view of regional territorial disputes. At the same time, it is keen to dispel the myths and stereotypes of the British and Hungarian historiography, which have so far viewed Hungary as an unimportant factor in British Central European strategy
A time-variable, phase-dependent emission line in the X-ray spectrum of the isolated neutron star RXJ0822–4300
Get PDFRX J0822−4300 is the central compact object associated with the Puppis A supernova remnant. Previous X-ray observations suggested RX J0822−4300 to be a young neutron star with a weak dipole field and a peculiar surface temperature distribution dominated by two antipodal spots with different temperatures and sizes. An emission line at 0.8 keV was also detected. We performed a very deep (130-ks) observation with XMM–Newton, which allowed us to study in detail the phase-resolved properties of RX J0822−4300. Our new data confirm the existence of a narrow spectral feature, best modelled as an emission line, only seen in the ‘soft’-phase interval – when the cooler region is best aligned to the line of sight. Surprisingly, comparison of our recent observations to the older ones yields evidence for a variation in the emission-line component, which can be modelled as a decrease in the central energy from ∼0.80 keV in 2001 to ∼0.73 keV in 2009–10. The line could be generated via cyclotron scattering of thermal photons in an optically-thin layer of gas, or, alternatively, it could originate in low-rate accretion by a debris disc. In any case, a variation in energy, pointing to a variation of the magnetic field in the line-emitting region, cannot be easily accounted for
On the binary nature of the γ-ray sources AGL J2241+4454 (= MWC 656) and HESS J0632+057 (= MWC 148)
No full textWe present optical spectroscopy of MWC 656 and MWC 148, the proposed optical counterparts of the gamma-ray sources AGL J2241+4454 and HESS J0632+0 57, respectively. The main parameters of the Halpha emission line (EW, FWHM and centroid velocity) in these stars are modulated on the proposed orbital periods of 60.37 and 321 days, respectively. These modulations are likely produced by the resonant interaction of the Be discs with compact stars in eccentric orbits. We also present radial velocity curves of the optical stars folded on the above periods and obtain the first orbital elements of the two gamma-ray sources thus confirming their binary nature. Our orbital solution support eccentricities e~0.4 and 0.83+-0.08 for MWC 656 and MWC 148, respectively. Further, our orbital elements imply that the X-ray outbursts in HESS J0632+057/MWC 148 are delayed ~0.3 orbital phases after periastron passage, similarly to the case of LS I +61 303. In addition, the optical photometric light curve maxima in AGL J2241+4454/MWC 656 occur ~0.25 phases passed periastron, similar to what is seen in LS I +61 303. We also find that the orbital eccentricity is correlated with orbital period for the known gamma-ray binaries. This is explained by the fact that small stellar separations are required for the efficient triggering of VHE radiation. Another correlation between the EW of Halpha and orbital period is also observed, similarly to the case of Be/X-ray binaries. These correlations are useful to provide estimates of the key orbital parameters Porb and e from the Halpha line in future Be gamma-ray binary candidates
/Si(001) layers and reducing the threading dislocation density by providing a preexisting dislocation source
No full textStrain relaxed Si1−Ge buffer layers on Si(001) can be used as virtual substrates for the growth of both strained Si and strained SiGe, which are suitable materials for sub-7 nm CMOS devices due to their enhanced carrier mobility. For industrial applications, the threading dislocation density (TDD) has to be as low as possible. However, a reduction of the TDD is limited by the balance between dislocation glide and nucleation as well as dislocation blocking. The relaxation mechanism of low strain Si0.98Ge0.02 layers on commercial substrates is compared to substrates with a predeposited SiGe backside layer, which provides threading dislocations at the edge of the wafer. It is shown that by the exploitation of this reservoir, the critical thickness for plastic relaxation is reduced and the formation of misfit dislocation bundles can be prevented. Instead, upon reaching the critical thickness, these preexisting dislocations simultaneously glide unhindered from the edge of the wafer toward the center. The resulting dislocation network is free of thick dislocation bundles that cause pileups, and the TDD can be reduced by one order of magnitude.This article may be downloaded for personal use only. Any other use requires prior permission
of the author and AIP Publishing. This article appeared in Journal of Applied Physics 128, 215305
(2020) and may be found at https://doi.org/10.1063/5.0032454
Phyllocnistis petronellii Brito & Lopez-Vaamonde & Gonçalves & Becker & Mielke & Moreira 2017
No full textPhyllocnistis petronellii Brito & Lopez –Vaamonde, sp. nov. Figs. 3Q, 4Q, 5, 6H, S 1; Tab. 2 Type material. French Guiana: Sinnamary, Paracou Research Station, 5°16’28.5” N 52°55’25.3” W, 30 m elevation. Preserved dried and pinned. C. Lopez – Vaamonde leg., 11.XI.2015. HOLOTYPE: #f (Sample ID: IO0535; Process ID: LEPPC2393–16), with genitalia on slide (GRPM 50–143), deposited at MNHN. PARATYPE: with no sex identified (Sample ID: IO0536; Process ID: LEPPC2394–16), deposited at MNHN. BIN registry for BOLD: ACY6760. Diagnosis. Dorsal forewing: lf is absent; tf 1 is indistinctly shaped, restricted to costal margin and fused to tf 2. tf 2 is distinctive with distal border marked by light brown scales, crossing the wing from costal to the inner margin. This species is similar to P. citrella and P. xylopiella, differentiated from these by the absence of lf. Description (Figs. 3Q, S 1; Tab. 2). Forewing length: 1.75 mm (n=2). Head: covered with white silver scales. Antennae long and filiform. Thorax: forewing ground color white silver. lf absent. tf 1 pale yellow, shape weakly defined, restricted to costal margin and fused to tf 2. The latter with same coloration, c-shaped, presenting a wellmarked distal border with light brown scales, crossing the wing entirely. tf 3 and tf 4 forming blotch covered by scales of same coloration as the tf 2 (III). Narrow, weakly defined, light gray band precedes as. Costal strigulae (a– c), emerge from the tf 2 and from the blotch formed by the tf 3 and tf 4. Other strigulae emerge from as. Basal portion of inner fringes pale yellow, with distal apex light gray. Hindwing reduced, formed by light gray scales and long fringes. Abdomen: covered with silvery white scales. Male genitalia: unknown. Female genitalia (Fig. 6H): abdominal segment VII subrectangular, VIII reduced. Apophyses similar in shape: anterior apophysis almost reaching the limit between the VI and VII abdominal segments; posterior apophysis reaching the limit between the VIII and VII abdominal segments, ~0.5 x the size of anal papilla. The latter covered with setae of different sizes randomly arranged at distal margin. Ductus bursae thin and membranous, connected to the corpus bursae; corpus bursae wide, thin, not sclerotized. Signum absent. Geographical distribution (Fig. 5). Known only from the type locality, Paracou CIRAD Research Station, Sinnamary, French Guiana. Natural history. P. petronellii adults were reared from two field-collected leaf mines (voucher number of host plant: P2015A/CLV086). The holotype herein described emerged on 20.XI.2015. The species co-author (C.L.-V.) collected a third leaf mine (voucher number of host plant: P2015A-CLV43), on 13.VI.2015, in the same host plant with a dead larva inside which was dissected out of the mine and successfully barcoded (process ID: LEPPC1389- 15). Host plant(s). Vismia guianensis (Aubl.) Pers. (Hypericaceae). The vouchers of the host plant from which both P. petronellii specimens were reared were identified by the tropical botanist Pascal Petronelli (Kourou, Guyane) and are deposited at the herbarium of the University Paul Sabatier, Toulouse, France (P2015A/CLV086 & P2015A- CLV43). Vismia is a small tree or shrub, with 80% of its species concentrated in Central and South America. V. guianensis is known to occur in Colombia, Venezuela, Guyana, French Guiana and Brazil (Mourão & Beltrati 2001; Di Stasi & Hiruma-Lima 2002). Almeida-Cortez & Melo-de-Pinna (2006) described the anatomy of a leaf mine on V. guianensis associated with an unidentified microlepidopterous larva in Brazil that could be conspecific to P. petronellii. This record should be further examined. Etymology. The species name, petronellii, is a patronym in honor of tropical botanist Pascal Petronelli for his help identifying our host plant vouchers.Published as part of Brito, Rosângela, Lopez-Vaamonde, Carlos, Gonçalves, Gislene L., Becker, Vitor O., Mielke, Olaf H. H. & Moreira, Gilson R. P., 2017, Taxonomic revision of Neotropical Phyllocnistis Zeller, 1848 (Lepidoptera: Gracillariidae), with descriptions of seven new species and host plant associations, pp. 301-352 in Zootaxa 4341 (3) on pages 319-320, DOI: 10.11646/zootaxa.4341.3.1, http://zenodo.org/record/104000
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