4,633 research outputs found
Encefalitis chagásica pseudotumoral en pacientes con SIDA: presentación atípica en uno de ellos e historia de la enfermedad en una pequeña serie de casos
Chagas' disease is an intracellular parasitic infection owed to a protozoarium, the Trypanosoma cruzi1, affecting a large population in Latinamerica. Within the region 15 to 16 million people are infected2.
The worldwide pandemia, due to the infection of the HIV 1 virus, also affects Latinamerican countries. The number of patients with this condition in Central and South Americas amounts to 1.6 million persons3,4. Therefore, both illnesses overlap in a broad geographical area and may coincide in the same patient.
The HIV infection, which causes the AIDS syndrome, impairs the immunological system and predisposes to the appearance of opportunistic infections, which may have been hosted unnoticed by the patient until then. Therefore, Chagas' disease, which is a dormant infection in most patients5, may reactivate if the immunological surveillance wanes off as the consequence of the viral insult. Along the last years we6,7 and others8-10 found patients afflicted by AIDS, who developed brain lesions yielded by the Trypanosoma cruzi.
The present communication describes three further patients with this condition; one of them is unique because his clinical, radiological and immunological findings differ from those previously reported in the literature.Fil: Sica, Roberto E. P.. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Gargiulo Monachelli, Gisella Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Papayanis, Cristina. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentin
A sufficient condition for the lower semicontinuity of nonlocal supremal functionals in the vectorial case
We present a sufficient condition ensuring lower semicontinuity for nonlocal supremal functionals of the type W 1,'(?; Rd) u I? ess sup W(x, y, Vu(x), Vu(y)), (x,y)E?x? where ? is a bounded open subset of RN and W: ? x ? x RdxN x RdxN ? R
Electronic transport within a quasi two-dimensional model for rubrene single-crystal field effect transistors
Spectral and transport properties of the quasi two-dimensional adiabatic
Su-Schrieffer-Heeger model are studied adjusting the parameters in order to
model rubrene single-crystal field effect transistors with small but finite
density of injected charge carriers. We show that, with increasing temperature
, the chemical potential moves into the tail of the density of states
corresponding to localized states, but this is not enough to drive the system
into an insulating state. The mobility along different crystallographic
directions is calculated including vertex corrections which give rise to a
transport lifetime one order of magnitude smaller than spectral lifetime of the
states involved in the transport mechanism. With increasing temperature, the
transport properties reach the Ioffe-Regel limit which is ascribed to less and
less appreciable contribution of itinerant states to the conduction process.
The model provides features of the mobility in close agreement with
experiments: right order of magnitude, scaling as a power law ,
with close or larger than two, and correct anisotropy ratio between
different in-plane directions. Due to a realistic high dimensional model, the
results are not biased by uncontrolled approximations.Comment: 10 pages, 9 figures, Submitte
Designing for User Confidence in Intelligent Environments
Intelligent environments aim at supporting and assisting users in their daily activities. Their reliability, i.e., the capability of correctly accomplishing the intended tasks and of limiting or avoiding damage in case of malfunctions, is essential as for any user-facing technology. One aspect of reliability, often neglected, is guaranteeing the consistency between system operation and user expectations, so that users may build confidence over the correct behavior of the system and its reaction to their actions. The paper will review the literature concerning methodologies and tools that directly involve users and have been specifically applied or adopted for intelligent environments, throughout the entire design flow – from requirements gathering to interface design. The paper will then propose, building on top of the previous analysis, a set of guidelines that system designers should follow to ensure user confidence in their intelligent environments
A Novel Broadband Forcecardiography Sensor for Simultaneous Monitoring of Respiration, Infrasonic Cardiac Vibrations and Heart Sounds
The precordial mechanical vibrations generated by cardiac contractions have a rich frequency spectrum. While the lowest frequencies can be palpated, the higher infrasonic frequencies are usually captured by the seismocardiogram (SCG) signal and the audible ones correspond to heart sounds. Forcecardiography (FCG) is a non-invasive technique that measures these vibrations via force sensing resistors (FSR). This study presents a new piezoelectric sensor able to record all heart vibrations simultaneously, as well as a respiration signal. The new sensor was compared to the FSR-based one to assess its suitability for FCG. An electrocardiogram (ECG) lead and a signal from an electro-resistive respiration band (ERB) were synchronously acquired as references on six healthy volunteers (4 males, 2 females) at rest. The raw signals from the piezoelectric and the FSR-based sensors turned out to be very similar. The raw signals were divided into four components: Forcerespirogram (FRG), Low-Frequency FCG (LF-FCG), High-Frequency FCG (HF-FCG) and heart sounds (HS-FCG). A beat-by-beat comparison of FCG and ECG signals was carried out by means of regression, correlation and Bland–Altman analyses, and similarly for respiration signals (FRG and ERB). The results showed that the infrasonic FCG components are strongly related to the cardiac cycle (R2 > 0.999, null bias and Limits of Agreement (LoA) of ± 4.9 ms for HF-FCG; R2 > 0.99, null bias and LoA of ± 26.9 ms for LF-FCG) and the FRG inter-breath intervals are consistent with ERB ones (R2 > 0.99, non-significant bias and LoA of ± 0.46 s). Furthermore, the piezoelectric sensor was tested against an accelerometer and an electronic stethoscope: synchronous acquisitions were performed to quantify the similarity between the signals. ECG-triggered ensemble averages (synchronized with R-peaks) of HF-FCG and SCG showed a correlation greater than 0.81, while those of HS-FCG and PCG scored a correlation greater than 0.85. The piezoelectric sensor demonstrated superior performances as compared to the FSR, providing more accurate, beat-by-beat measurements. This is the first time that a single piezoelectric sensor demonstrated the ability to simultaneously capture respiration, heart sounds, an SCG-like signal (i.e., HF-FCG) and the LF-FCG signal, which may provide information on ventricular emptying and filling events. According to these preliminary results the novel piezoelectric FCG sensor stands as a promising device for accurate, unobtrusive, long-term monitoring of cardiorespiratory functions and paves the way for a wide range of potential applications, both in the research and clinical fields. However, these results should be confirmed by further analyses on a larger cohort of subjects, possibly including also pathological patients
Editorial Preface: Elderly Mobility
This Special Issue of TeMA Journal of Land Use, Mobility and Environment collects the research works of one
of the sessions organised in the framework of the XX Scientific Meeting of the Società Italiana degli
Economisti dei Trasporti e della Logistica (SIET), focused on the MOBILAGE (Mobility and aging: daily life
and welfare supportive networks at the neighbourhood level) research project financed by Fondazione
Cariplo within the “Aging and social research: people, places and relations” 2017 Call for scientific research.
The session was addressed to investigate elderly (people aged 65+) mobility, by exploring the supply and
demand of Local Public Transport (LPT) in urban areas
Vps28 is involved in the intracellular trafficking of AWD, the Drosophila homolog of NMe1/2
The Awd (abnormal wing discs) gene is the Drosophila homolog of human NME1 and NME2 metastasis suppressor genes. These genes play a key role in tumor progression. Extensive studies revealed that intracellular NME1/2 protein levels could be related to either favorable or poor prognosis depending on tissue context. More recently, extracellular activities of NME1/2 proteins have also been reported, including a tumor- promoting function. We used Drosophila as a genetic model to investigate the mechanism controlling intra- and extracellular levels of NME1/2. We examined the role of several components of the ESCRT (endosomal sorting complex required for transport) complex in controlling Awd trafficking. We show that the Vps28 component of the ESCRT 12I complex is required for maintenance of normal intracellular level of Awd in larval adipocytes. We already showed that blocking of Shibire (Shi)/Dynamin function strongly- lowers Awd intracellular level. To further investigate this down regulative effect, we analyzed the distribution of endosomal markers in wild type and Shi-defective adipocytes. Our results suggest that Awd does not enter CD63-positive endosomes. Interestingly, we found that in fat body cells, Awd partly- colocalizes with the ESCRT accessory component ALiX, the ALG-2 (apoptosis-linked gene 2)-interacting protein X. Moreover, we show that the intracellular levels of both proteins are downregulated by blocking the function of the Dynamin encoded by the shibire gene
Dynamic ride sharing service: are users ready to adopt it?
Nowadays we are experiencing a shift of paradigm from ownership of goods to sharing goods and experiences. The “sharing economy” paradigm will change the way people experience everyday life in many sectors. In this paper we are focusing on the urban transportation experience presenting a user centric design of an experimental dynamic ridesharing service for Italian users, called VirtualBus [1]. The proposed service is based on a mobile application that allows people to get arrangement in real time for sharing car rides in an urban area, both as “driver” or “passenger”. A smart matching algorithm will provide, within a short time, the best matching between the driver and the passenger learning from users’ feedbacks and improving its suggestions overtime to better fulfill users’ expectations. The service was designed, prototyped and tested involving users in every step, starting from a vision board with the target Personas. Then, a first raw prototype of the mobile application was designed and tested during specific focus group sessions. During the focus groups users highlighted both the importance of defining rewarding and payment rules and some concerns about privacy and reliability of drivers and passengers. Moreover, a large scale questionnaire, with more than 500 respondents, was distributed with the focus on two big Italian cities, Turin and Rome. The questionnaire analysis gave many interesting insights about the city commuting habits and its results were used to enrich the previously designed Personas with the aim of enhancing real users’ scenarios. Next steps will involve real users on selected cities as a test-bed of both the technical solution and the users’ acceptability of a new way of experiencing the urban commuting
Chemo-Archaeological Downsizing in a Hierarchical Universe: Impact of a Top Heavy IGIMF
We make use of a semi-analytical model of galaxy formation to investigate the
origin of the observed correlation between [a/Fe] abundance ratios and stellar
mass in elliptical galaxies. We implement a new galaxy-wide stellar initial
mass function (Top Heavy Integrated Galaxy Initial Mass Function, TH-IGIMF) in
the semi-analytic model SAG and evaluate its impact on the chemical evolution
of galaxies. The SFR-dependence of the slope of the TH-IGIMF is found to be key
to reproducing the correct [a/Fe]-stellar mass relation. Massive galaxies reach
higher [a/Fe] abundance ratios because they are characterized by more top-heavy
IMFs as a result of their higher SFR. As a consequence of our analysis, the
value of the minimum embedded star cluster mass and of the slope of the
embedded cluster mass function, which are free parameters involved in the
TH-IGIMF theory, are found to be as low as 5 solar masses and 2, respectively.
A mild downsizing trend is present for galaxies generated assuming either a
universal IMF or a variable TH-IGIMF. We find that, regardless of galaxy mass,
older galaxies (with formation redshifts > 2) are formed in shorter time-scales
(< 2 Gyr), thus achieving larger [a/Fe] values. Hence, the time-scale of galaxy
formation alone cannot explain the slope of the [a/Fe]-galaxy mass relation,
but is responsible for the big dispersion of [a/Fe] abundance ratios at fixed
stellar mass.We further test the hyphothesis of a TH-IGIMF in elliptical
galaxies by looking into mass-to-light ratios, and luminosity functions. Models
with a TH-IGIMF are also favoured by these constraints. In particular,
mass-to-light ratios agree with observed values for massive galaxies while
being overpredicted for less massive ones; this overprediction is present
regardless of the IMF considered.Comment: 24 pages, 15 figures, 2 tables. (Comments most welcome). Summited to
MNRA
A standalone bioreactor system to deliver compressive load under perfusion flow to hBMSC-seeded 3D chitosan-graphene templates
The availability of engineered biological tissues holds great potential for both clinical applications and basic research in a life science laboratory. A prototype standalone perfusion/compression bioreactor system was proposed to address the osteogenic commitment of stem cells seeded onboard of 3D chitosan-graphene (CHT/G) templates. Testing involved the coordinated administration of a 1 mL/min medium flow rate together with dynamic compression (1% strain at 1 Hz; applied twice daily for 30 min) for one week. When compared to traditional static culture conditions, the application of perfusion and compression stimuli to human bone marrow stem cells using the 3D CHT/G template scaffold induced a sizable effect. After using the dynamic culture protocol, there was evidence of a larger number of viable cells within the inner core of the scaffold and of enhanced extracellular matrix mineralization. These observations show that our novel device would be suitable for addressing and investigating the osteogenic phenotype commitment of stem cells, for both potential clinical applications and basic research
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