James-Jacques-Joseph Tissot

Edgar Degas; 4 ft. 11 39/64 in. x 3 ft. 10 1/2 in.; oil on canvas

Top-hat random fiber Bragg grating

We examined the possibility of using noise or pseudo-random variations of the refractive index in the design of fiber Bragg gratings (FBGs). We demonstrated theoretically and experimentally that top-hat FBGs may be designed and fabricated using this approach. The reflectivity of the fabricated top-hat FBG matches quite well with that of the designed one. © 2015 Optical Society of America.

HIV-1 and T cell dynamics after interruption of highly active antiretroviral therapy (HAART) in patients with a history of sustained viral suppression

Identifying the immunologic and virologic consequences of discontinuing antiretroviral therapy in HIV-infected patients is of major importance in developing long-term treatment strategies for patients with HIV-1 infection. We designed a trial to characterize these parameters after interruption of highly active antiretroviral therapy (HAART) in patients who had maintained prolonged viral suppression on antiretroviral drugs. Eighteen patients with CD4+ T cell counts ≥ 350 cells/μl and viral load below the limits of detection for ≥1 year while on HAART were enrolled prospectively in a trial in which HAART was discontinued. Twelve of these patients had received prior IL-2 therapy and had low frequencies of resting, latently infected CD4 cells. Viral load relapse to >50 copies/ml occurred in all 18 patients independent of prior IL-2 treatment, beginning most commonly during weeks 2–3 after cessation of HAART. The mean relapse rate constant was 0.45 (0.20 log10 copies) day−1, which was very similar to the mean viral clearance rate constant after drug resumption of 0.35 (0.15 log10 copies) day−1 (P = 0.28). One patient experienced a relapse delay to week 7. All patients except one experienced a relapse burden to >5,000 RNA copies/ml. Ex vivo labeling with BrdUrd showed that CD4 and CD8 cell turnover increased after withdrawal of HAART and correlated with viral load whereas lymphocyte turnover decreased after reinitiation of drug treatment. Virologic relapse occurs rapidly in patients who discontinue suppressive drug therapy, even in patients with a markedly diminished pool of resting, latently infected CD4+ T cells.

The story of … the top hat

Throughout the 19th century, the top hat was a mainstay of Victorian life: a man in a topper was well-to-do, respectable, a man of industry. But now the top hat is only a caricature of the upper class privilege it once represented. Its history traces a line through dandies, beavers, silk, and madness...

Studio portrait of unidentified woman wearing a man's suit and hat Portraits Women

Signed and dated by photographer

Studio portrait of Benno Strauss in military uniform after being drafted to fight on the front during World War I at the age of thirty-nine.

Father of Herbert Strauss

Studio portrait of Anna Hoch Hauser seated and holding a copy of the book "Geschichten Aus Tirol" by Carl Wolf; Vienna Portraits Women

Digital Image

Numerical Partition of Energy Absorption of Foam-filled Top-Hat and Double-Hat Sections

The interaction effect, i.e., the contribution of each component to the total energy absorption of an axially crushed foam-filled hat section was investigated quantitatively via numerical simulation. The FE results were first verified by experimental work of aluminum foam-filled top-hat and double-hat sections, then the contribution of foam-fillers and that of hat sections to the overall energy absorption were quantitatively obtained, respectively. When foam-filled, increase in energy absorption was found both in hat section component and foam-filler component, whereas the latter contributes predominantly to the interaction effect.

Evolução top-hat hidrodinâmica em campos de velocidades peculiares primordiais

We investigate the cosmology of the vacuum energy decaying into cold dark matter according to thermodynamics description of Alcaniz & Lima. We apply this model to analyze the evolution of primordial density perturbations in the matter that gave rise to the first generation of structures bounded by gravity in the Universe, called Population III Objects. The analysis of the dynamics of those systems will involve the calculation of a differential equation system governing the evolution of perturbations to the case of two coupled fluids (dark matter and baryonic matter), modeled with a Top-Hat profile based in the perturbation of the hydrodynamics equations, an efficient analytical tool to study the properties of dark energy models such as the behavior of the linear growth factor and the linear growth index, physical quantities closely related to the fields of peculiar velocities at any time, for different models of dark energy. The properties and the dynamics of current Universe are analyzed through the exact analytical form of the linear growth factor of density fluctuations, taking into account the influence of several physical cooling mechanisms acting on the density fluctuations of the baryonic component of matter during the evolution of the clouds of matter, studied from the primordial hydrogen recombination. This study is naturally extended to more general models of dark energy with constant equation of state parameter in a flat Universe

Studio di Mutazioni Geniche e Variazioni Copy-Number implicate nel deficit combinato degli Ormoni Ipofisari(CPHD)

La crescita normale di un individuo è il risultato dell’azione coordinata di molteplici ormoni e recettori codificati da geni e a tal proposito, discreto interesse è stato dato ai geni tipici dell’asse del GH. Tuttavia altri geni, più a monte di questi e responsabili dello sviluppo dell’ipofisi contribuiscono alla crescita normale o patologica. Alcuni geni studiati sono POU1F1, PROP1, LHX3, LHX4, HESX1, SOX3 e svariate loro mutazioni sono state identificate come causa di panipopituarismo (CPHD=Combined Pituitary Hormone Deficiency). In realtà la ricerca genetica non spiega ancora molte anomalie ipofisarie e molte mutazioni devono ancora essere identificate. Uno degli scopi del dottorato, svoltosi nel laboratorio di Genetica molecolare di Pediatria, è stata l’identificazione di mutazioni geniche da un gruppo di pazienti CPHD considerando in particolare i geni POU1F1, LHX3, SOX3, non ancora messi a punto presso il laboratorio. L’approccio sperimentale si è basato sulle seguenti fasi: prelievo delle informazioni di sequenza da GeneBank, progettazione di primers per amplificare le porzioni esoniche, messa a punto delle fasi della PCR e del sequenziamento, analisi della sequenza e confronto con le informazioni di sequenza depositate allo scopo di rintracciare eventuali mutazioni o varianti. La bassa percentuale di mutazioni in questi geni non ha permesso finora di rintracciare mutazioni nelle porzioni esoniche salvo che in un soggetto, nell’esone 6 di LHX3b (nuova mutazione, recessiva eterozigote, c.1248A>G implicata nella mutazione p.T377A della sequenza proteica). Un metodo di screening di questa mutazione impiegando l’enzima di restrizione SacII è stato usato, senza rilevare nessun altra occorrenza dell’allele mutato in 53 soggetti di controllo. Oltre alla messa a punto del sequenziamento e di alcune tecniche di analisi di singoli SNP o piccoli INDELs per i 3 geni, la ricerca svolta è stata orientata all’impiego di metodi di rilevamento di riarrangiamenti genetici comportanti ampie delezioni e/o variazioni del copy-number di esoni/interi geni detto MLPA (Multiplex Ligation-dependent Probe Amplification) e progettato da MRC-Holland. Il sequenziamento infatti non permette di rilevare tali alterazioni quando sono ampie ed in eterozigosi. Per esempio, in un’ampia delezione in eterozigosi, l’intervallo delimitato dai primers usati per la PCR può non includere totalmente la porzione interessata da delezione su un cromosoma cosicché la PCR ed il sequnziamento si basano solo sulle informazioni dell’altro cromosoma non deleto. Un vantaggio della tecnica MLPA, è l’analisi contemporanea di una quarantina di siti posti su svariati geni. Questa metodo tuttavia può essere affetto da un certo margine di errore spesso dipendente dalla qualità del DNA e dovrebbe essere affiancato e validato da altre tecniche più impegnativa dal punto di vista sperimentale ma più solide, per esempio la Real Time PCR detta anche PCR quantitativa (qPCR). In laboratorio, grazie all’MLPA si è verificata la condizione di delezione eterozigote di un paziente “storico” per il gene GH1 e la stessa mutazione è stata rilevata anche con la qPCR usando lo strumento Corbett Rotor Gene 6000 (Explera). Invece un’analisi solo con la qPCR di variazioni del copy-number (CNV) per SOX3 in pazienti maschili non ha ancora evidenziato anomalie. Entrambe le tecniche hanno aspetti interessanti, il miglior approccio al momento sembra un’analisi iniziale di pazienti con l’MLPA, seguita dalla verifica di un eventuale esito anomalo impiegando la real-time PCR.

A randomised determination of the effect of fluvastatin and atorvastatin on top of dual antiplatelet treatment on platelet aggregation after implantation of coronary drug-eluting stents. The EFA-Trial

Drug-drug interaction between statins metabolised by cytochrome P450 3A4 and clopidogrel have been claimed to attenuate the inhibitory effect of clopidogrel. However, published data regarding this drug-drug interaction are controversial. We aimed to determine the effect of fluvastatin and atorvastatin on the inhibitory effect of dual antiplatelet therapy with acetylsalicylic acid (ASA) and clopidogrel. One hundred one patients with symptomatic stable coronary artery disease undergoing percutaneous coronary intervention and drug-eluting stent implantation were enrolled in this prospective randomised study. After an interval of two weeks under dual antiplatelet therapy with ASA and clopidogrel, without any lipid-lowering drug, 87 patients were randomised to receive a treatment with either fluvastatin 80 mg daily or atorvastatin 40 mg daily in addition to the dual antiplatelet therapy for one month. Platelet aggregation was assessed using light transmission aggregometry and whole blood impedance platelet aggregometry prior to randomisation and after one month of receiving assigned statin and dual antiplatelet treatment. Platelet function assessment after one month of statin and dual antiplatelet therapy did not show a significant change in platelet aggregation from 1st to 2nd assessment for either statin group. There was also no difference between atorvastatin and fluvastatin treatment arms. In conclusion, neither atorvastatin 40 mg daily nor fluvastatin 80 mg daily administered in combination with standard dual antiplatelet therapy following coronary drug-eluting stent implantation significantly interfere with the antiaggregatory effect of ASA and clopidogrel.

Shaping the PSF to nearly top-hat profile: CHEOPS laboratory results

Spreading the PSF over a quite large amount of pixels is an increasingly used observing technique in order to reach extremely precise photometry, such as in the case of exoplanets searching and characterization via transits observations. A PSF top-hat profile helps to minimize the errors contribution due to the uncertainty on the knowledge of the detector flat field. This work has been carried out during the recent design study in the framework of the ESA small mission CHEOPS. Because of lack of perfect flat-fielding information, in the CHEOPS optics it is required to spread the light of a source into a well defined angular area, in a manner as uniform as possible. Furthermore this should be accomplished still retaining the features of a true focal plane onto the detector. In this way, for instance, the angular displacement on the focal plane is fully retained and in case of several stars in a field these look as separated as their distance is larger than the spreading size. An obvious way is to apply a defocus, while the presence of an intermediate pupil plane in the Back End Optics makes attractive to introduce here an optical device that is able to spread the light in a well defined manner, still retaining the direction of the chief ray hitting it. This can be accomplished through an holographic diffuser or through a lenslet array. Both techniques implement the concept of segmenting the pupil into several sub-zones where light is spread to a well defined angle. We present experimental results on how to deliver such PSF profile by mean of holographic diffuser and lenslet array. Both the devices are located in an intermediate pupil plane of a properly scaled laboratory setup mimicking the CHEOPS optical design configuration. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Top-Hat HELLISH-VCSOA for optical amplification and wavelength conversion for 0.85 to 1.3ìm operation

The Top-Hat hot electron light emission and lasing in semiconductor heterostructure (HELLISH)-vertical cavity semiconductor optical amplifier (VCSOA) is a modified version of a HELLISH-VCSOA device. It has a shorter p-channel and longer n-channel. The device studied in this work consists of a simple GaAs p-i-n junction, containing 11 Ga0.35In0.65 N0.02As0.08/GaAs multiple quantum wells in its intrinsic region; the active region is enclosed between six pairs of GaAs/AlAs top distributed Bragg reflector (DBR) mirrors and 20.5 pairs of AlAs/GaAs bottom DBR mirrors. The operation of the device is based on longitudinal current transport parallel to the layers of the GaAs p-n junction. The device is characterised through I-V-L and by spectral photoluminescence, electroluminescence and electro-photoluminescence measurements. An amplification of about 25 dB is observed at applied voltages of around V = 88 V.

BET on Top Hat: challenges to improve language proficiency

Within the business context, communication and interaction tends to be considerably rooted in the use of English (as lingua franca), as well as in ICT use. Thus, professionals have to be able to speak the English language, resorting to specific, internationally recognised terminology and be proficient in the use of manifold ICT tools. In fact, the tendency is for the great majority of higher education (HE) students to own mobile devices (laptops, smartphones and/or tablets) and use them to access information and communicate/interact with content and other people. Bearing this in mind, a teaching and learning strategy was designed, in which m-learning (i.e. learning in which the delivery platform is a mobile device) was used to approach Business English Terminology (BET). The strategy was labelled as ‘BET on Top Hat’, once the selected application was Top Hat (https://tophat.com/) and the idea was for students to face it as if it were a game/challenge. In this scenario, the main goals of this exploratory study were to find evidence as to: i) the utility of m-learning activities for learning BET and ii) if and how m-learning activities can generate intrinsic motivation in students to learn BET. Participants (n=23) were enrolled in English II, a curricular unit of the 1st cycle degree in Retail Management offered at Águeda School of Technology and Management – University of Aveiro (2014/15 edition). The data gathered included the students’ results in quizzes and their answers to a short final evaluation questionnaire regarding their experience with BET on Top Hat. Consequently, data were treated and analysed resorting to descriptive statistical analysis, and, when considered pertinent, the teacher’s observation notes were also considered. The results unveil that, on the one hand, the strategy had a clear positive impact on the students’ intrinsic motivation and, on the other hand, the students’ performance as to BET use tended to improve over time.

Studio portrait of the six daughters of Solomon and Emilie Kohnberger: (l-r) Laura, Irene, Johanna, Melanie, Hermine and Martha.

Laura (1878-1917) died during a flu epidemic. She married Sigmund Stiassny and had two children, Lisbeth (Gersuny) (1900-1986) and Walter (1902-1912) who died of a ruptured appendix.