1,563 research outputs found
Trichinellosis in Vietnam
Trichinellosis is a zoonotic parasitic disease with a worldwide distribution. The aim of this work was to describe the epidemiological and clinical data of five outbreaks of trichinellosis, which affected ethnic minorities living in remote mountainous areas of northwestern Vietnam from 1970 to 2012. Trichinellosis was diagnosed in 126 patients, of which 11 (8.7%) were hospitalized and 8 (6.3%) died. All infected people had consumed raw pork from backyard and roaming pigs or wild boar at wedding, funeral, or New Year parties. The short incubation period (average of 9.5 days), the severity of the symptoms, which were characterized by diarrhea, abdominal pain, fever, myalgia, edema, weight loss, itch, and lisping, and the high mortality, suggest that patients had ingested a high number of larvae. The larval burden in pigs examined in one of the outbreaks ranged from 70 to 879 larvae/g. These larvae and those collected from a muscle biopsy taken from a patient from the 2012 outbreak were identified as Trichinella spiralis. Data presented in this work show that the northern regions of Vietnam are endemic areas for Trichinella infections in domestic pigs and humans
<i>Echinococcus granulosus</i> in the Lombardy region
Cystic echinococcosis (Echinococcus granulosus) is a significant public health problem in the Mediterranean basin. In Italy, there are few epidemiological studies on echinococcosis in animals and humans mainly on southern regions, even if echinoccocosis is included in the list of zoonoses that need an epidemiological surveillance (2003/99/EEC of 17 November 2003). The results confirm that echinococcosis is hypoendemic in Lombardy, but data collected at the slaughterhouse could underestimate the prevalence of the infection, because old sheep are not always slaughtered under veterinary control
Validation of a Western Blot for the detection of anti- Trichinella spp. antibodies in domestic pigs
Trichinellosis is a zoonotic disease in humans caused by Trichinella spp. According to international regulations and guidelines, serological surveillance can be used to demonstrate the absence of Trichinella spp. in a defined domestic pig population. Most enzyme-linked immunosorbent assay (ELISA) tests presently available do not yield 100% specificity, and therefore, a complementary test is needed to confirm the diagnosis of any initial ELISA seropositivity. The goal of the present study was to evaluate the sensitivity and specificity of a Western Blot assay based on somatic Trichinella spiralis muscle stage (L1) antigen using Bayesian modeling techniques. A total of 295 meat juice and serum samples from pigs negative for Trichinella larvae by artificial digestion, including 74 potentially cross-reactive sera of pigs with other nematode infections, and 93 meat juice samples from pigs infected with Trichinella larvae were included in the study. The diagnostic sensitivity and specificity of the Western Blot were ranged from 95.8% to 96.0% and from 99.5% to 99.6%, respectively. A sensitivity analysis showed that the model outcomes were hardly influenced by changes in the prior distributions, providing a high confidence in the outcomes of the models. This validation study demonstrated that the Western Blot is a suitable method to confirm samples that reacted positively in an initial ELIS
A Sample of Very Young Field L Dwarfs and Implications for the Brown Dwarf "Lithium Test" at Early Ages
Using a large sample of optical spectra of late-type dwarfs, we identify a
subset of late-M through L field dwarfs that, because of the presence of
low-gravity features in their spectra, are believed to be unusually young. From
a combined sample of 303 field L dwarfs, we find observationally that
7.6+/-1.6% are younger than 100 Myr. This percentage is in agreement with
theoretical predictions once observing biases are taken into account. We find
that these young L dwarfs tend to fall in the southern hemisphere (Dec < 0 deg)
and may be previously unrecognized, low-mass members of nearby, young
associations like Tucana-Horologium, TW Hydrae, beta Pictoris, and AB Doradus.
We use a homogeneously observed sample of roughly one hundred and fifty
6300-10000 Angstrom spectra of L and T dwarfs taken with the Low-Resolution
Imaging Spectrometer at the W. M. Keck Observatory to examine the strength of
the 6708-A Li I line as a function of spectral type and further corroborate the
trends noted by Kirkpatrick et al. (2000). We use our low-gravity spectra to
investigate the strength of the Li I line as a function of age. The data weakly
suggest that for early- to mid-L dwarfs the line strength reaches a maximum for
a few 100 Myr, whereas for much older (few Gyr) and much younger (<100 Myr) L
dwarfs the line is weaker or undetectable. We show that a weakening of lithium
at lower gravities is predicted by model atmosphere calculations, an effect
partially corroborated by existing observational data. Larger samples
containing L dwarfs of well determined ages are needed to further test this
empirically. If verified, this result would reinforce the caveat first cited in
Kirkpatrick et al. (2006) that the lithium test should be used with caution
when attempting to confirm the substellar nature of the youngest brown dwarfs.Comment: 73 pages with 22 figures; to appear in ApJ (Dec 20, 2008, v689n2
issue
Investigation on Opisthorchis felineus occurrence and life cycle in Italy
Opisthorchiasis is a fish borne parasitic infection caused by helminths of the genus
Opisthorchis (Digenea, Opisthorchiidae), affecting humans and other fish-eating mammals.
Despite Opisthorchis felineus was first described in Italy in 1884, no cases of human
opisthorchiasis were reported in this country until 2004; from then on, 4 outbreaks due to
this species have been recorded in Central Italy. Following the more relevant of these outbreaks,
involving 34 people in August 2007, snails, fishes and fecal samples collected from
the Bolsena and Bracciano lakes (Central Italy) were analyzed in order to define the cycle
of O. felineus in the area and investigate its prevalence in the different hosts. Pools of 20–40
snails each (4983 specimens altogether) of the genus Bithynia were analyzed by PCR for
parasite DNA detection. Eight hundred and ninety-four fish belonging to 12 species were
collected from the two lakes and tested for metacercariae both by muscle compression and
digestion techniques. Eighty-seven fecal samples of 5 putative definitive host species were
collected very close to the two lakes and tested for parasite eggs detection by formalin–ethyl
acetate concentration technique. Identification at the species level of metacercariae and
eggs, respectively, from fish and stool was confirmed by PCR analysis and sequencing. O.
felineus DNA was detected in 0.08% (overall minimum infection rate) of snails of the genus
Bithynia from the two lakes. The tench, Tinca tinca, was the only fish found infested in both
lakes (prevalence 88.5%). O. felineus eggs were found only in cat feces (prevalence 46.4%).
The tench represents the only threat for the human consumption in the study area while
Coregonus sp., the most economically important species for the local fishery and frequently
consumed raw marinated, resulted to be not infected. The high prevalence recorded both
in fish and in definitive host suggests a widespread and massive presence of the parasite in
the area. Further studies are needed to better investigate the possible role of some cyprinids
species as intermediate hosts, in order to check their safety for human consumption
Analyses of Compact Trichinella Kinomes Reveal a MOS-like Protein Kinase with a Unique N-terminal Domain
Parasitic worms of the genus Trichinella (phylum Nematoda; class Enoplea) represent a complex of at least twelve taxa that infect a range of different host animals, including humans, around the world. They are foodborne, intracellular nematodes, and their life cycles differ substantially from those of other nematodes. The recent characterization of the genomes and transcriptomes of all twelve recognized taxa of Trichinella now allows, for the first time, detailed studies of their molecular biology. In the present study, we defined, curated, and compared the protein kinase complements (kinomes) of Trichinella spiralis and T. pseudospiralis using an integrated bioinformatic workflow employing transcriptomic and genomic data sets. We examined how variation in the kinome might link to unique aspects of Trichinella morphology, biology, and evolution. Furthermore, we utilized in silico structural modeling to discover and characterize a novel, MOS-like kinase with an unusual, previously undescribed N-terminal domain. Taken together, the present findings provide a basis for comparative investigations of nematode kinomes, and might facilitate the identification of Enoplea-specific intervention and diagnostic targets. Importantly, the in silico modeling approach assessed here provides an exciting prospect of being able to identify and classify currently unknown (orphan) kinases, as a foundation for their subsequent structural and functional investigation
Effect of Low Cobalt Loading on TiO2 Nanotube Arrays for Water-Splitting
This work is intended to define a new possible methodology for the TiO2doping through the use of an electrochemical deposition of cobalt directly on the titanium nanotubes obtained by a previous galvanostatic anodization treatment in an ethylene glycol solution. This method does not seem to cause any influence on the nanotube structure, showing final products with news and interesting features with respect to the unmodified sample. Together with an unmodified photoconversion efficiency under UV light, the cobalt doped specimen reports an increase of the electrocatalytic efficiency for the oxygen evolution reaction (OER)
Studying the Physical Diversity of Late-M Dwarfs with Dynamical Masses
We present a systematic study of the physical properties of late-M dwarfs
based on high-quality dynamical mass measurements and near-infrared (NIR)
spectra. We use astrometry from Keck NGS and LGS AO imaging to determine orbits
for late-M binaries. We find that LP 349-25 (M7.5+M8) is a pair of young brown
dwarfs (Mtot = 0.120 Msun) for which Lyon and Tucson evolutionary models
jointly predict an age of 140+/-30 Myr. This is consistent with the age of the
Pleiades, but at least LP 349-25A defies the empirical Pleiades lithium
depletion boundary, implying that the system is in fact older and that
evolutionary models underpredict the component luminosities. We find that LHS
1901AB (M6.5+M6.5) is a pair of very low-mass stars (Mtot = 0.194 Msun) with
model-derived ages consistent with limits from its lack of activity (> 6 Gyr).
Our improved orbit for Gl 569Bab (M8.5+M9) results in a higher mass for this
binary (Mtot = 0.140 Msun) compared to previous work (0.125 Msun). We use these
masses along with our published results for 2MASS J2206-2047AB (M8+M8) to test
four sets of ultracool model atmospheres currently in use. Fitting these models
to our NIR integrated-light spectra provides temperature estimates warmer by
~250 K than those derived independently from Dusty evolutionary models given
the measured masses and luminosities. We propose that model atmospheres are
more likely to be the source of this discrepancy, as it would be difficult to
explain a uniform temperature offset over such a wide range of masses, ages,
and activity levels in the context of evolutionary models. Our results contrast
those of Konopacky et al. as we find an opposite and smaller mass discrepancy
from what they report when we adopt their model-testing approach since our Teff
estimates from fitting spectra are ~650 K higher than from their fitting of
broadband photometry alone.Comment: 53 pages, 12 figures, accepted to Ap
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