Gnathostomiasis is a prevalent zoonosis in humans in some regions of the world. The genus Gnathostoma is considered an accidental parasite for humans; G. binucleatum is the endemic species in ...Nayarit, Mexico. This work was designed to determine the proteolytic activity of the excretory-secretory products (ESP) of advanced third-stage larvae (ADVL3) of Gnathostoma binucleatum against human fibronectin and antibodies from human and sheep. Our findings showed protease activity against human fibronectin as well as sheep and human gamma globulins of the ESP at molecular weights of 80 and 56 kDa. The proteases found in the ESP of G. binucleatum are thus candidate molecules for consideration as pathogenic elements, owing to the fact that they destroy proteins of the host tissue, which probably allows them to migrate through those tissues and degrade molecules involved in the humoral immune response.
The GAPS Programme at TNG Carleo, I.; Malavolta, L.; Lanza, A. F. ...
Astronomy and astrophysics (Berlin),
06/2020, Volume:
638
Journal Article
Peer reviewed
Open access
Context.
The existence of hot Jupiters is still not well understood. Two main channels are thought to be responsible for their current location: a smooth planet migration through the protoplanetary ...disk or the circularization of an initial highly eccentric orbit by tidal dissipation leading to a strong decrease in the semimajor axis. Different formation scenarios result in different observable effects, such as orbital parameters (obliquity and eccentricity) or frequency of planets at different stellar ages.
Aims.
In the context of the GAPS Young Objects project, we are carrying out a radial velocity survey with the aim of searching and characterizing young hot-Jupiter planets. Our purpose is to put constraints on evolutionary models and establish statistical properties, such as the frequency of these planets from a homogeneous sample.
Methods.
Since young stars are in general magnetically very active, we performed multi-band (visible and near-infrared) spectroscopy with simultaneous GIANO-B + HARPS-N (GIARPS) observing mode at TNG. This helps in dealing with stellar activity and distinguishing the nature of radial velocity variations: stellar activity will introduce a wavelength-dependent radial velocity amplitude, whereas a Keplerian signal is achromatic. As a pilot study, we present here the cases of two known hot Jupiters orbiting young stars: HD 285507 b and AD Leo b.
Results.
Our analysis of simultaneous high-precision GIARPS spectroscopic data confirms the Keplerian nature of the variation in the HD 285507 radial velocities and refines the orbital parameters of the hot Jupiter, obtaining an eccentricity consistent with a circular orbit. Instead, our analysis does not confirm the signal previously attributed to a planet orbiting AD Leo. This demonstrates the power of the multi-band spectroscopic technique when observing active stars.
The immune response of teleosts (bonefish) is altered by diazinon (DZN), an organophosphate pesticide. It has been suggested that such alteration is due to the extraneuronal cholinergic system in ...fish leukocytes that renders these cells a target of pesticides.
Diazoxon (DZO), the oxon metabolite of DZN, has been attributed immunotoxic effects. Still, to date there are no reports on the effects of DZO upon parameters involved in the signaling cascade of immune response cells. Therefore, this work evaluated the effect of DZO on key parameters of cell signaling (intracellular Ca2+ flux, ERK 1/2 phosphorylation), cell proliferation, and antiproliferative processes (apoptosis, senescence, mitochondrial membrane potential) in spleen mononuclear cells of Nile tilapia fish. The results obtained show that DZO does not affect cell proliferation but causes a lack of response to stimulation with PMA and ionomycin to release intracellular calcium. In addition, it inhibits ERK 1/2 phosphorylation and causes loss of mitochondrial membrane potential, apoptosis, and senescence. These results suggest that the lack of cell response to release intracytoplasmic Ca2+ inhibits ERK which disrupts the mitochondrial membrane potential, leading to cell apoptosis and senescence. These findings prove that DZO significantly affects key parameters involved in the survival of immune response cells.
•DZO causes disturbances in intracellular Ca2+ flow in fish mononuclear cells.•DZO inhibits ERK1/2 phosphorylation in fish mononuclear cells.•DZO induces apoptosis, senescence, and loss of ΔΨm in fish mononuclear cells.
Context.
Stellar activity is currently challenging the detection of young planets via the radial velocity (RV) technique.
Aims.
We attempt to definitively discriminate the nature of the RV variations ...for the young active K5 star BD+20 1790, for which visible (VIS) RV measurements show divergent results on the existence of a substellar companion.
Methods.
We compare VIS data with high precision RVs in the near-infrared (NIR) range by using the GIANO–B and IGRINS spectrographs. In addition, we present for the first time simultaneous VIS-NIR observations obtained with GIARPS (GIANO–B and HARPS–N) at Telescopio Nazionale Galileo (TNG). Orbital RVs are achromatic, so the RV amplitude does not change at different wavelengths, while stellar activity induces wavelength-dependent RV variations, which are significantly reduced in the NIR range with respect to the VIS.
Results.
The NIR radial velocity measurements from GIANO–B and IGRINS show an average amplitude of about one quarter with respect to previously published VIS data, as expected when the RV jitter is due to stellar activity. Coeval multi-band photometry surprisingly shows larger amplitudes in the NIR range, explainable with a mixture of cool and hot spots in the same active region.
Conclusions.
In this work, the claimed massive planet around BD+20 1790 is ruled out by our data. We exploited the crucial role of multi-wavelength spectroscopy when observing young active stars: thanks to facilities like GIARPS that provide simultaneous observations, this method can reach its maximum potential.
Temephos and spinosad are pesticides used for control of vector-borne diseases such as dengue, chikungunya and zika. However, the inadequate use of these substances has affected the health of ...non-target organisms. The aim of this study was to evaluate and compare, the effects of temephos and spinosad on leukocyte viability and death, using guppy fish (Poecilia reticulate) as a model organism. Guppies were exposed to temephos (10 mg/L) and spinosad (0.5 mg/L) for 7, 14, and 21 days. Afterwards, they were placed in pesticide-free fish tanks (7, 35, and 70 days) for recovery. The results showed that exposure to temephos caused leukocyte death, even at 35 days of recovery. Contrarily, the exposure to spinosad did not cause leukocyte death. This research show, for the first time, that a single dose of temephos causes apoptosis up to 56 days post-exposition, indicating that this pesticide induces chronic effects on immune response cells.
Context. Stellar activity is currently challenging the detection of young planets via the radial velocity (RV) technique. Aims. We attempt to definitively discriminate the nature of the RV variations ...for the young active K5 star BD+20 1790, for which visible (VIS) RV measurements show divergent results on the existence of a substellar companion. Methods. We compare VIS data with high precision RVs in the near-infrared (NIR) range by using the GIANO–B and IGRINS spectrographs. In addition, we present for the first time simultaneous VIS-NIR observations obtained with GIARPS (GIANO–B and HARPS–N) at Telescopio Nazionale Galileo (TNG). Orbital RVs are achromatic, so the RV amplitude does not change at different wavelengths, while stellar activity induces wavelength-dependent RV variations, which are significantly reduced in the NIR range with respect to the VIS. Results. The NIR radial velocity measurements from GIANO–B and IGRINS show an average amplitude of about one quarter with respect to previously published VIS data, as expected when the RV jitter is due to stellar activity. Coeval multi-band photometry surprisingly shows larger amplitudes in the NIR range, explainable with a mixture of cool and hot spots in the same active region. Conclusions. In this work, the claimed massive planet around BD+20 1790 is ruled out by our data. We exploited the crucial role of multi-wavelength spectroscopy when observing young active stars: thanks to facilities like GIARPS that provide simultaneous observations, this method can reach its maximum potential.
ABSTRACT The first documented cases of Coronavirus disease of 2019 (COVID-19) in Wuhan city (Hubei province, China) were caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), ...studies mention viral transmission is more common in indoor and poorly ventilated environments compared to outdoor environments or environments with abundant airflow. In this context, this research aimed to estimate, through a mathematical model by a Box-Behnken design, the time and occupancy required in a physical space to reach CO2 levels that exceed the risk level established as a safer condition of 700 ppm for SARS-CoV-2 transmission. According to the proposed mathematical model, it is possible to predict safe conditions. With this, it was found that natural ventilation is the best option to reduce CO2 concentration, considering the occupancy/m3 and time, allowing a constant airflow; the use of air conditioners to control the temperature in rooms without natural ventilation is suggested; notwithstanding, these types of equipment are not designed to reduce CO2 concentration. Thus, their use in rooms with open windows and doors leads to a shorter equipment lifetime, for this reason, its operation in special conditions, such as in rooms without natural ventilation should be considered.
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