2,005 research outputs found
Aditivo orgánico en raciones para pacú (Piaractus mesopotamicus) en período reproductivo. Efecto sobre la recuperación de lesiones
El objetivo del presente trabajo fue evaluar la recuperación de lesiones en reproductores de pacú (Piaractus mesopotamicus) utilizando un reparador metabólico a base de flavonoides ofrecido antes o después de las maniobras reproductivas (inducción y desove) en el alimento. Se utilizaron 39 ejemplares de pacú, los que se distribuyeron aleatoriamente en tres grupos según el tipo de alimento ofrecido: (G1) ración comercial; (G2) ración comercial hasta las maniobras reproductivas donde cambia a ración comercial adicionada con 2 g/kg de Flavoxin®; y (G3) ración comercial adicionada con 2 g/kg de Flavoxin® durante todo el período experimental. El ensayo tuvo una duración de 69 días, período en el cual se realizaron biopsias ováricas como seguimiento de la maduración gonadal. Durante el período previo a la hipofisación y desove o espermiación, los reproductores mostraron buen estado general. Por el contrario, e inmediatamente posterior a las maniobras reproductivas, se observó un alto número de lesiones en tegumento y aletas en todos los ejemplares correspondientes al G1 y G2, destacándose el reducido número de lesiones en G3, el cual se diferenció estadísticamente (p<0,05). En G3 no se observaron lesiones posteriormente a los 9 días de las maniobras reproductivas, mientras que en G1 y G2 las mismas aún se encontraron presentes al final de la experiencia. Asimismo, al finalizar la experiencia el porcentaje de supervivencia del G2 fue el más bajo (60%), diferenciándose de G1 y G3 (p><0,05). Estos resultados demuestran que la utilización de 2 g/kg de Flavoxin® adicionado a raciones para reproductores de P. mesopotamicus, previamente a la realización de las maniobras reproductivas, permite una pronta recuperación de las lesiones post-desove o espermiación, mejorando el estado sanitario de los mismos>
Simultaneous PET-MRI Studies of the Concordance of Atrophy and Hypometabolism in Syndromic Variants of Alzheimer's Disease and Frontotemporal Dementia: An Extended Case Series
Background: Simultaneous PET-MRI is used to compare patterns of cerebral hypometabolism and atrophy in six different dementia syndromes. Objectives: The primary objective was to conduct an initial exploratory study regarding the concordance of atrophy and hypometabolism in syndromic variants of Alzheimer’s disease (AD) and frontotemporal dementia (FTD). The secondary objective was to determine the effect of image analysis methods on determination of atrophy and hypometabolism. Method: PET and MRI data were acquired simultaneously on 24 subjects with six variants of AD and FTD (n = 4 per group). Atrophy was rated visually and also quantified with measures of cortical thickness. Hypometabolism was rated visually and also quantified using atlas- and SPM-based approaches. Concordance was measured using weighted Cohen’s kappa. Results: Atrophy-hypometabolism concordance differed markedly between patient groups; kappa scores ranged from 0.13 (nonfluent/agrammatic variant of primary progressive aphasia, nfvPPA) to 0.49 (posterior cortical variant of AD, PCA). Heterogeneity was also observed within groups; the confidence intervals of kappa scores ranging from 0–0.25 for PCA to 0.29–0.61 for nfvPPA. More widespread MRI and PET changes were identified using quantitative methods than on visual rating. Conclusion: The marked differences in concordance identified in this initial study may reflect differences in the molecular pathologies underlying AD and FTD syndromic variants but also operational differences in the methods used to diagnose these syndromes. The superior ability of quantitative methodologies to detect changes on PET and MRI, if confirmed on larger cohorts, may favor their usage over qualitative visual inspection in future clinical diagnostic practic
A low energy core-collapse supernova without a hydrogen envelope
The final fate of massive stars depends on many factors, including mass,
rotation rate, magnetic fields and metallicity. Theory suggests that some
massive stars (initially greater than 25-30 solar masses) end up as Wolf-Rayet
stars which are deficient in hydrogen because of mass loss through strong
stellar winds. The most massive of these stars have cores which may form a
black hole and theory predicts that the resulting explosion produces ejecta of
low kinetic energy, a faint optical display and a small mass fraction of
radioactive nickel(1,2,3). An alternative origin for low energy supernovae is
the collapse of the oxygen-neon core of a relatively lowmass star (7-9 solar
masses) through electron capture(4,5). However no weak, hydrogen deficient,
core-collapse supernovae are known. Here we report that such faint, low energy
core-collapse supernovae do exist, and show that SN2008ha is the faintest
hydrogen poor supernova ever observed. We propose that other similar events
have been observed but they have been misclassified as peculiar thermonuclear
supernovae (sometimes labelled SN2002cx-like events(6)). This discovery could
link these faint supernovae to some long duration gamma-ray bursts. Extremely
faint, hydrogen-stripped core-collapse supernovae have been proposed to produce
those long gamma-ray bursts whose afterglows do not show evidence of
association with supernovae (7,8,9).Comment: Submitted 12 January 2009 - Accepted 24 March 200
Hepatitis A virus strains circulating in the Campania region (2015-2018) assessed through bivalve biomonitoring and environmental surveillance
The genetic diversity of Hepatitis A Virus (HAV) circulating in the Campania Region in years 2015-2018 was investigated through the monitoring of sentinel bivalve shellfish and water matrices. Overall, 463 water samples (71 sewage samples, 353 coastal discharge waters, and 39 seawaters samples), and 746 bivalve shellfish samples were analyzed. Positivity for HAV was detected in 20/71 sewage samples, 14/353 coastal discharge waters, 5/39 seawaters, and 102/746 bivalve shellfish. Sixty-one of the positive samples were successfully sequenced and were characterized as genotype IA (n = 50) and IB (n = 11). The prevalent strain circulating in 2015 in both bivalves and waters was the IA strain responsible for the outbreak occurring around the same time in the Naples area. This variant was no longer identified in subsequent years (2017-2018) when, instead, appeared two of the IA variants of the multistate outbreak affecting men who have sex with men (MSM), VRD_521_2016, and RIVM-HAV16-090, with the former prevailing in both shellfish and water environments. HAV IB isolates were detected over the years in shellfish and in water matrices, but not in clinical samples, suggesting that this genotype had been circulating silently. An integrated surveillance system (environment/food/clinical cases) can be a useful tool to monitor changes in viral variants in the population, as well as an early warning system
Early-type galaxies with core collapse supernovae
It is widely accepted that the progenitors of core collapse SNe are young
massive stars and therefore their host galaxies are mostly spiral or irregular
galaxies dominated by a young stellar population. Surprisingly, among
morphologically classified hosts of core collapse SNe, we find 22 cases where
the host has been classified as an Elliptical or S0 galaxy. To clarify this
apparent contradiction, we carry out a detailed morphological study and an
extensive literature search for additional information on the sample objects.
Our results are as follows: 1. Of 22 "early type" objects, 17 are in fact
misclassified spiral galaxies, one is a misclassified irregular, and one is a
misclassified ring galaxy. 2. Of the 3 objects maintaining the early type
classification, one (NGC2768) is a suspected merger remnant, another (NGC4589)
is definitely a merger, and the third (NGC2274) is in close interaction. The
presence of some amount of young stellar population in these galaxies is
therefore not unexpected. These results confirm the presence of a limited, but
significant, number of core collapse SNe in galaxies generally classified of
early type. In all cases, anyway, there are independent indicators of the
presence in host galaxies of recent star formation due to merging or
gravitational interaction.Comment: 12 pages, 1 figure, 1 table, accepted for publication in A&
Human Herpesvirus-8 Infection Leads to Expansion of the Preimmune/Natural Effector B Cell Compartment
BACKGROUND: Human herpesvirus-8 (HHV-8) is the etiological agent of Kaposi's sarcoma (KS) and of some lymphoproliferative disorders of B cells. Most malignancies develop after long-lasting viral dormancy, and a preventing role for both humoral and cellular immune control is suggested by the high frequency of these pathologies in immunosuppressed patients. B cells, macrophages and dendritic cells of peripheral lymphoid organs and blood represent the major reservoir of HHV-8. Due to the dual role of B cells in HHV-8 infection, both as virus reservoir and as agents of humoral immune control, we analyzed the subset distribution and the functional state of peripheral blood B cells in HHV-8-infected individuals with and without cKS. METHODOLOGY/PRINCIPAL FINDINGS: Circulating B cells and their subsets were analyzed by 6-color flow cytometry in the following groups: 1- patients HHV-8 positive with classic KS (cKS) (n = 47); 2- subjects HHV-8 positive and cKS negative (HSP) (n = 10); 3- healthy controls, HHV-8 negative and cKS negative (HC) (n = 43). The number of B cells belonging to the preimmune/natural effector compartment, including transitional, pre-naïve, naïve and MZ-like subsets, was significantly higher among HHV-8 positive subjects, with or without cKS, while was comparable to healthy controls in the antigen-experienced T-cell dependent compartment. The increased number of preimmune/natural effector B cells was associated with increased resistance to spontaneous apoptosis, while it did not correlate with HHV-8 viral load. CONCLUSIONS/SIGNIFICANCE: Our results indicate that long-lasting HHV-8 infection promotes an imbalance in peripheral B cell subsets, perturbing the equilibrium between earlier and later steps of maturation and activation processes. This observation may broaden our understanding of the complex interplay between viral and immune factors leading HHV-8-infected individuals to develop HHV-8-associated malignancies
SN 2012ec: Mass of the progenitor from PESSTO follow-up of the photospheric phase
We present the results of a photometric and spectroscopic monitoring campaign of SN 2012ec, which exploded in the spiral galaxy NGC 1084, during the photospheric phase. The photometric light curve exhibits a plateau with luminosity L = 0.9 × 1042 erg s−1 and duration ∼90 d, which is somewhat shorter than standard Type II-P supernovae (SNe). We estimate the nickel mass M(56Ni) = 0.040 ± 0.015 M from the luminosity at the beginning of the radioactive tail of the light curve. The explosion parameters of SN 2012ec were estimated from the comparison of the bolometric light curve and the observed temperature and velocity evolution of the ejecta with predictions from hydrodynamical models. We derived an envelope mass of 12.6 M, an initial progenitor radius of 1.6 × 1013 cm and an explosion energy of 1.2 foe. These estimates agree with an independent study of the progenitor star identified in
pre-explosion images, for which an initial mass of M = 14−22 M was determined. We have applied the same analysis to two other Type II-P SNe (SNe 2012aw and 2012A), and carried out a comparison with the properties of SN 2012ec derived in this paper. We find a reasonable agreement between the masses of the progenitors obtained from pre-explosion images and masses derived from hydrodynamical models. We estimate the distance to SN 2012ec with
the standardized candle method (SCM) and compare it with other estimates based on other primary and secondary indicators. SNe 2012A, 2012aw and 2012ec all follow the standard relations for the SCM for the use of Type II-P SNe as distance indicators
The perception of healthcare quality of elderly in the city of Bari, South Italy
<p>Abstract</p> <p>Background</p> <p>In recent decades in Italy, as in all the industrialized nations, the proportion of elderly subjects in the total population is constantly on the increase. However the increased life expectancy is not always paralleled by a true improvement in the quality of life.</p> <p>In this context, it is essential to analyze elderly real health needs and the responses to these needs, especially in terms of healthcare, that the territorial services are perceived to offer.</p> <p>Methods</p> <p>In the period from June to September 2006 we selected randomly one General Practitioner (GP) for each district of the Bari Municipal Area and, form each GP, we randomly chose 25 patients over 65 years old (YO). We conducted phone interviews using a standard data collection questionnaire and, for each of the recruited subjects, the GP filled a data collection sheet.</p> <p>Results</p> <p>Although the mean age (73.6 years) of the population under study was quite high, the general state of health was judged good both by the G P- and by their elderly patients (>75%).</p> <p>Notably, the great majority of elderly patients considered the healthcare they receive to be satisfactory (>60%): in particular, the GP was the true point of reference for this slice of the population for strictly medical problems as well as for advice. On the contrary, the patients attributed little value to social services, which were poorly known and scarcely used (8.5%). Public hospital facilities played a central role in second level healthcare in more than 30% of cases; private facilities covered by public health insurance were also very important. As possible solutions to the problem of loneliness, 36.6% of the patients declared that they approved of nursing homes.</p> <p>Conclusion</p> <p>Decision makers need to create services supporting the key role played by General Practitioners, who are well aware that their assistance is not sufficient to satisfy the health needs of the elderly.</p
Photometric and Spectroscopic study of a highly reddened type Ia supernova SN 2003hx in NGC 2076
We present CCD photometry and optical spectra of the type Ia
supernova SN 2003hx which appeared in the galaxy NGC 2076, obtained till
146 days after the epoch of band maximum. The supernova reached at maximum
brightness in band on JD 245 2893 1.0 with an apparent magnitude of
14.92 0.01 mag which was estimated by making template fits to the light
curves. SN 2003hx is an example of a highly reddened supernova with =
0.56 0.23. We estimate = 1.97 0.54 which indicates the small
size of dust particles as compared to their galactic counterparts. The
luminosity decline rate is = 1.17 0.12 mag and the
absolute band magnitude obtained from the luminosity versus decline rate
relation (Phillips et al. 1999) is = -19.20 0.18 mag. The
peak bolometric luminosity indicates that 0.66 mass of
Ni was ejected by the supernova. The spectral evolution indicates the supernova
to be a normal type Ia event.Comment: 16 pages, 21 figures, 5 tables, Accepted for publication in MNRA
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