81 research outputs found
Multilayer Regulation of Neisseria meningitidis NHBA at Physiologically Relevant Temperatures
Neisseria meningitidis colonizes the nasopharynx of humans, and pathogenic strains can disseminate into the bloodstream, causing septicemia and meningitis. NHBA is a surface-exposed lipoprotein expressed by all N. meningitidis strains in different isoforms. Diverse roles have been reported for NHBA in heparin-mediated serum resistance, biofilm formation, and adherence to host tissues. We determined that temperature controls the expression of NHBA in all strains tested, with increased levels at 30–32◦C compared to 37◦C. Higher NHBA expression at lower temperatures was measurable both at mRNA and protein levels, resulting in higher surface exposure. Detailed molecular analysis indicated that multiple molecular mechanisms are responsible for the thermoregulated NHBA expression. The comparison of mRNA steady-state levels and half-lives at 30◦C and 37◦C demonstrated an increased mRNA stability/translatability at lower temperatures. Protein stability was also impacted, resulting in higher NHBA stability at lower temperatures. Ultimately, increased NHBA expression resulted in higher susceptibility to complement-mediated killing. We propose that NHBA regulation in response to temperature downshift might be physiologically relevant during transmission and the initial step(s) of interaction within the host nasopharynx. Together these data describe the importance of NHBA both as a virulence factor and as a vaccine antigen during neisserial colonization and invasion
Wavelength-shifter coated polystyrene as an easy-to-build and low-cost plastic scintillator detector
We studied the light yield of a pure polystyrene slide coated with
wavelength-shifter molecules, coupled to a photomultiplier, using beta
particles from a 90-Sr source, as a possible easy-to-build, low-cost plastic
scintillator detector. Comparison measurements were performed with an uncoated
polystyrene slide as well as with uncoated and coated PMMA slides, the latter
which can only produce Cherenkov light when being traversed by charged
particles. The results with the single (double) coated polystyrene slides show
about 4.9 (6.3) times higher detected photon yield compared to the uncoated
slide. For comparison, the light yield of a polystyrene-based extruded plastic
scintillator material doped with PTP and POPOP was measured as well. The
absolute detected light yield motivates future studies for developing
easy-to-build, low-cost polystyrene-based plastic scintillator detectors.Comment: 20 pages, 13 figure
Combining exposure indicators and predictive analytics for threats detection in real industrial IoT sensor networks
We present a framework able to combine exposure indicators and predictive analytics using AI-tools and big data architectures for threats detection inside a real industrial IoT sensors network. The described framework, able to fill the gaps between these two worlds, provides mechanisms to internally assess and evaluate products, services and share results without disclosing any sensitive and private information. We analyze the actual state of the art and a possible future research on top of a real case scenario implemented into a technological platform being developed under the H2020 ECHO project, for sharing and evaluating cybersecurity relevant informations, increasing trust and transparency among different stakeholders
Impiego di un programma integrato di bioattivazione per il controllo della polmonite micoplasmica del suino
Introduzione. La qualit\ue0 dell\u2019aria nelle strutture di allevamento dei suini dipende soprattutto dalla concentrazione dei biogas,
derivati dall\u2019azione della flora microbica fecale sull\u2019urea contenuta nelle urine; il peggioramento della qualit\ue0 ambientale
\ue8 alla base di molti problemi sanitari, basati in primo luogo sull\u2019impossibilit\ue0 degli animali a mantenere un bilancio organico
corretto. Una soluzione possibile e innovativa \ue8 rappresentata dalla bioattivazione con miscele batterico-enzimatiche; per questa
via, si pu\uf2 ottenere una riduzione delle emanazioni, controllando anche la formazione di sostanze dannose per l\u2019ambiente.
Materiali e metodi. \uc8 stato programmato un intervento in due aziende suinicole (il reparto di magronaggio-ingrasso di un
ciclo chiuso completo e un allevamento di solo ingrasso), per controllare il danno indotto dall\u2019infezione micoplasmica nelle
fasi di produzione a flusso continuo; sono stati messi a confronto gruppi trattati e non trattati, diversi tipi di pavimentazione
(grigliato completo, concreto completo e misto grigliato-concreto) e pi\uf9 schemi d\u2019intervento, utilizzando, da soli o in combinazione,
bioattivatori in polvere e liquidi. Il sistema di bioattivazione impiegato comprende due bioattivatori (in polvere e soluzione)
e un prodotto naturale di origine vegetale da aggiungere alla razione alimentare. La polvere \ue8 stata distribuita sulle pavimentazioni,
in ragione di 0,5 Kg per 100 mq ogni 15 giorni mediante spargimento manuale, mentre la soluzione \ue8 stato aerosolizzata
nell\u2019ambiente di stabulazione, mediante impianto computerizzato, in ragione di 1 litro ogni 100 mq al mese; il prodotto
vegetale, per la sua composizione in grado di riequilibrare la flora intestinale, \ue8 stato invece aggiunto quotidianamente
alla razione, in ragione di 500 g/t di mangime.
I rilievi e le osservazioni hanno riguardato la concentrazione di azoto ammoniacale (rilevata con metodo chimico), la presenza
di anticorpi specifici per M. hyopneumoniae prima e dopo il periodo di trattamento (valutata con metodo ELISA), i punteggi
polmonari al macello (valutati con metodo quantitativo) e il peso medio di partita.
Risultati. In tutti i gruppi trattati, la sieroprevalenza per M. hyopneumoniae \ue8 stata elevata, a dimostrazione della circolazione
dell\u2019infezione nel periodo di osservazione, ma la diminuzione della concentrazione ambientale dell\u2019ammoniaca, ottenuta grazie
all\u2019impiego dei bioattivatori) ha permesso di ottenere benefici evidenti sul punteggio polmonare medio, confermati dalla
significativit\ue0 statistica delle differenze, e sul peso medio di partita. In rapporto ai tipi di pavimentazione, la bioattivazione ha
fornito i risultati migliori combinando polvere e liquido sul grigliato completo.
Conclusioni. I risultati ottenuti dimostrano che nelle situazioni di allevamento, la stabilizzazione del bilancio organico degli
animali attraverso una gestione ambientale che ne garantisca anche il benessere \ue8 una soluzione attuabile, in una logica di depotenziamento
delle infezioni; essi sono la conseguenza dell\u2019accresciuta reattivit\ue0 degli animali, correlata ad un miglior bilancio
organico, piuttosto che l\u2019effetto di un\u2019azione diretta sui patogeni; \ue8 in corso la valutazione della reattivit\ue0 immunitaria aspecifica
dei suini sottoposti a trattamento, per correlare stato sanitario e produttivit\ue0 al miglioramento della qualit\ue0 ambientale
Adherence to Antihypertensive Medications andCardiovascular Morbidity Among Newly DiagnosedHypertensive Patients
Background—Nonadherence to antihypertensive treatment is a common problem in cardiovascular prevention and may
influence prognosis. We explored predictors of adherence to antihypertensive treatment and the association of adherence
with acute cardiovascular events.
Methods and Results—Using data obtained from 400 Italian primary care physicians providing information to the Health
Search/Thales Database, we selected 18 806 newly diagnosed hypertensive patients 35 years of age during the years
2000 to 2001. Subjects included were newly treated for hypertension and initially free of cardiovascular diseases. Patient
adherence was subdivided a priori into 3 categories— high (proportion of days covered, 80%), intermediate
(proportion of days covered, 40% to 79%), and low (proportion of days covered, 40%)—and compared with the
long-term occurrence of acute cardiovascular events through the use of multivariable models adjusted for demographic
factors, comorbidities, and concomitant drug use. At baseline (ie, 6 months after index diagnosis), 8.1%, 40.5%, and
51.4% of patients were classified as having high, intermediate, and low adherence levels, respectively. Multiple drug
treatment (odds ratio, 1.62; 95% CI, 1.43 to 1.83), dyslipidemia (odds ratio, 1.52; 95% CI, 1.24 to 1.87), diabetes
mellitus (odds ratio, 1.40; 95% CI, 1.15 to 1.71), obesity (odds ratio, 1.50; 95% CI, 1.26 to 1.78), and antihypertensive
combination therapy (odds ratio, 1.29; 95% CI, 1.15 to 1.45) were significantly (P0.001) associated with high
adherence to antihypertensive treatment. Compared with their low-adherence counterparts, only high adherers reported
a significantly decreased risk of acute cardiovascular events (hazard ratio, 0.62; 95% CI, 0.40 to 0.96; P0.032).
Conclusions—The long-term reduction of acute cardiovascular events associated with high adherence to antihypertensive
treatment underscores its importance in assessments of the beneficial effects of evidence-based therapies in the
population. An effort focused on early antihypertensive treatment initiation and adherence is likely to provide major
benefits
Experimental study of a R290 variable geometry ejector
Ejectors are classified as fluid-dynamics controlled devices where the "component-scale"performances are imposed by the local-scale fluid dynamic phenomena. For this reason, ejector performances (measured by the pressure-entrainment ratio coordinate of the critical point) are determined by the connection of operation conditions, working fluid and geometrical parameters. Given such a connection, variable geometry ejector represents a promising solution to increase the flexibility of ejector-based systems. The present study aims to extend knowledge on variable geometry systems, evaluating the local and global performances of the R290 ejector equipped with a spindle. The prototype ejector was installed at the R290 vapour compression test rig adapted and modified for the required experimental campaign. The test campaign considered global parameter measurements, such as the pressure and the temperature at inlets and outlet ports together with the mass flow rates at both inlet nozzles, and the local pressure drop measurements inside the ejector. In addition, the experimental data were gathered for different spindle positions starting from fully open position the spindle position limited by the mass flow rate inside the test rig with the step of 1.0 mm
Gaugino Mass Nonuniversality and Dark Matter in SUGRA, Strings and D Brane Models
The effects of nonuniversality of gaugino masses on dark matter are examined
within supersymmetric grand unification, and in string and D brane models with
R parity invariance. In SU(5) unified models nonuniversality in the gaugino
sector can be generated via the gauge kinetic energy function which may depend
on the 24, 75 and 200 dimensional Higgs representations. We also consider
string models which allow for nonuniversality of gaugino masses and D brane
models where nonuniversality arises from embeddings of the Standard Model gauge
group on five branes and nine branes. It is found that with gaugino mass
nonuniversality the range of the LSP mass can be extended much beyond the range
allowed in the universal SUGRA case, up to about 600 GeV even without
coannihilation effects in some regions of the parameter space. The effects of
coannihilation are not considered and inclusion of these effects may further
increase the allowed neutralino mass range. Similarly with the inclusion of
gaugino mass nonuniversality, the neutralino-proton () cross-section
can increase by as much as a factor of 10 in some of regions of the parameter
space. An analysis of the uncertainties in the quark density content of the
nucleon is given and their effects on cross-section are discussed.
The predictions of our analysis including nonuniversality is compared with the
current limits from dark matter detectors and implications for future dark
matter searches are discussed.Comment: Revised version, 23 pages, Latex, and 7 figure
Track reconstruction and matching between emulsion and silicon pixel detectors for the SHiP-charm experiment
In July 2018 an optimization run for the proposed charm cross section measurement for SHiP was performed at the CERN SPS. A heavy, moving target instrumented with nuclear emulsion films followed by a silicon pixel tracker was installed in front of the Goliath magnet at the H4 proton beam-line. Behind the magnet, scintillating-fibre, drift-tube and RPC detectors were placed. The purpose of this run was to validate the measurement's feasibility, to develop the required analysis tools and fine-tune the detector layout. In this paper, we present the track reconstruction in the pixel tracker and the track matching with the moving emulsion detector. The pixel detector performed as expected and it is shown that, after proper alignment, a vertex matching rate of 87% is achieved.Peer Reviewe
The SHiP experiment at the proposed CERN SPS Beam Dump Facility
The Search for Hidden Particles (SHiP) Collaboration has proposed a general-purpose experimental facility operating in beam-dump mode at the CERN SPS accelerator to search for light, feebly interacting particles. In the baseline configuration, the SHiP experiment incorporates two complementary detectors. The upstream detector is designed for recoil signatures of light dark matter (LDM) scattering and for neutrino physics, in particular with tau neutrinos. It consists of a spectrometer magnet housing a layered detector system with high-density LDM/neutrino target plates, emulsion-film technology and electronic high-precision tracking. The total detector target mass amounts to about eight tonnes. The downstream detector system aims at measuring visible decays of feebly interacting particles to both fully reconstructed final states and to partially reconstructed final states with neutrinos, in a nearly background-free environment. The detector consists of a 50 m long decay volume under vacuum followed by a spectrometer and particle identification system with a rectangular acceptance of 5 m in width and 10 m in height. Using the high-intensity beam of 400 GeV protons, the experiment aims at profiting from the 4 x 10(19) protons per year that are currently unexploited at the SPS, over a period of 5-10 years. This allows probing dark photons, dark scalars and pseudo-scalars, and heavy neutral leptons with GeV-scale masses in the direct searches at sensitivities that largely exceed those of existing and projected experiments. The sensitivity to light dark matter through scattering reaches well below the dark matter relic density limits in the range from a few MeV/c(2) up to 100 MeV-scale masses, and it will be possible to study tau neutrino interactions with unprecedented statistics. This paper describes the SHiP experiment baseline setup and the detector systems, together with performance results from prototypes in test beams, as it was prepared for the 2020 Update of the European Strategy for Particle Physics. The expected detector performance from simulation is summarised at the end
Track reconstruction and matching between emulsion and silicon pixel detectors for the SHiP-charm experiment
In July 2018 an optimization run for the proposed charm cross section measurement for SHiP was performed at the CERN SPS. A heavy, moving target instrumented with nuclear emulsion films followed by a silicon pixel tracker was installed in front of the Goliath magnet at the H4 proton beam-line. Behind the magnet, scintillating-fibre, drift-tube and RPC detectors were placed. The purpose of this run was to validate the measurement's feasibility, to develop the required analysis tools and fine-tune the detector layout. In this paper, we present the track reconstruction in the pixel tracker and the track matching with the moving emulsion detector. The pixel detector performed as expected and it is shown that, after proper alignment, a vertex matching rate of 87% is achieved
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