58 research outputs found
INTRAGUILD INTERACTIONS BETWEEN EGG PARASITOIDS: FROM LABORATORY TO FIELD INVESTIGATIONS
Field studies on egg parasitoid guilds of herbivore stink bugs, serious pests for a wide number of crops, have shown that Trissolcus spp. and Ooencyrtus spp. can naturally co-occur in the same host, and generally the former parasitize more eggs than the latter. In many countries, to control such pests, biological control programs based on egg parasitoids have been used obtaining inconstantly success. Thereby, understanding the competitive interactions among Trissolcus and Ooencyrtus species may be useful in order to improve biological control of such pests but only few researchers have investigated the effects of competitive interactions among these egg parasitoids. The aim of this thesis was to address on extrinsic and intrinsic competitive interaction that occur between Trissolcus basalis (Hymenoptera: Platygastridae) and Ooencyrtus telenomicida (Hymenoptera: Encyrtidae), two egg parasitoids of the southern green stink bug (SGSB), Nezara viridula (Heteroptera: Pentatomidae) in laboratory conditions and field and semifield conditions.
In laboratory conditions intraguild interactions between O. telenomicida and T. basalis, as the former has the potential to be a facultative hyperparasitoid of the latter has been investigated.
In 2nd chapter Has been assessed the suitability of N. viridula eggs for the development of O. telenomicida as a function of egg age when they were unparasitized, or had been attacked by T. basalis at different times prior to exposure to O. telenomicida females. Ooencyrtus telenomicida can exploit healthy N. viridula host eggs up to 5 days of age, just prior to the emergence of N. viridula. This window of opportunity can be extended for an additional 6–7 days through interspecific competition or facultative hyperparasitism. While there are minor fitness costs for O. telenomicida as the result of interspecific larval competition, those costs are greater with facultative hyperparasitism. In choice assays O. telenomicida females discriminated between different quality N. viridula eggs, avoiding those where their progeny would have to develop as facultative hyperparasitoids of T. basalis. Results are discussed with respect to the possible effects that the costs of intraguild parasitism might have on biological control programmes.
In 3rd chapter the interactions between egg parasiotids in natural conditions has been analyzed. Infact research on interspecific competitive interactions among insect parasitoids has often been characterized by laboratory studies in which host insects are exposed to female parasitoids of different species in various sequences and combinations. Therefore, the lack of bioassays carried out under natural conditions is a key limiting aspect in understanding how interspecific interactions could affect pest suppression. In this scenario, for two-year has been investigated interspecific interactions between Trissolcus basalis (Wollaston) (Hymenoptera: Platygastridae) and Ooencyrtus telenomicida (Vassiliev) (Hymenoptera: Encyrtidae), two egg parasitoids of the pest Nezara viridula (L.) (Heteroptera: Pentatomidae) that co-occur in cultivated crops. Under semi-field (in out-door mesh cages) and field conditions, the follows parameters have been investigated: 1) the seasonal occurrence of competing parasitoid species on sentinel egg masses under natural conditions; 2) the parasitism impact achieved by competing species on the shared host on naturally laid egg masses under natural conditions; 3) the outcome of manipulating intraguild interactions. Results from sentinel egg masses showed that T. basalis occurs in May and successfully parasitizes hosts until the end of September/beginning of October, whereas O. telenomicida is mainly occurring in July-August. In both years, it was found that T. basalis is predominant. From naturally laid egg masses, results indicated that T. basalis achieves the highest parasitism impact on the hosts, even in those egg masses which are parasitized by more than one female of different species (= multiparasitism). Results from manipulating intraguild interactions showed that T. basalis achieves the highest parasitism impact on N. viridula when released alone, but it suffers from competition with O. telenomicida. The ecological factors that play a role in intraguild interactions in the context of biological control perspective are discussed.
In 4th chapter it has been studied how the presence of synthetic Methyl salicilate can influence the intraguild competitive interaction between Trissolcus basalis (Wollaston) (Hymenoptera: Platygastridae) and Ooencyrtus telenomicida (Vassiliev) (Hymenoptera: Encyrtidae), two egg parasitoids of the southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae). Field experiments has been conducted, using sentinel egg masses placed randomly on the pepper plants. The following parameters have been evaluated: 1) the proportion of parasitized egg masses out of the total to assess the ability of the parasitoid to locate the host; 2) the proportion of individual eggs exploited out of the total egg number of the located egg masses to evaluate the ability of the parasitoid to exploit the host. The results demonstrated that T. basalis has a high ability to find host compared to O. telenomicida and that this ability is not affected by the presence of Methyl salicylate. Furthermore, it was shown that T. basalis is able to parasitize a higher number of eggs than O. telonimicida
Antagonism of the prokineticin system prevents and reverses allodynia and inflammation in a mouse model of diabetes
Neuropathic pain is a severe diabetes complication and its treatment is not satisfactory. It is associated with neuroinflammation-related events that participate in pain generation and chronicization. Prokineticins are a new family of chemokines that has emerged as critical players in immune system, inflammation and pain. We investigated the role of prokineticins and their receptors as modulators of neuropathic pain and inflammatory responses in experimental diabetes. In streptozotocin-induced-diabetes in mice, the time course expression of prokineticin and its receptors was evaluated in spinal cord and sciatic nerves, and correlated with mechanical allodynia. Spinal cord and sciatic nerve pro- and anti-inflammatory cytokines were measured as protein and mRNA, and spinal cord GluR subunits expression studied. The effect of preventive and therapeutic treatment with the prokineticin receptor antagonist PC1 on behavioural and biochemical parameters was evaluated. Peripheral immune activation was assessed measuring macrophage and T-helper cytokine production. An up-regulation of the Prokineticin system was present in spinal cord and nerves of diabetic mice, and correlated with allodynia. Therapeutic PC1 reversed allodynia while preventive treatment blocked its development. PC1 normalized prokineticin levels and prevented the up-regulation of GluN2B subunits in the spinal cord. The antagonist restored the pro-/anti-inflammatory cytokine balance altered in spinal cord and nerves and also reduced peripheral immune system activation in diabetic mice, decreasing macrophage proinflammatory cytokines and the T-helper 1 phenotype. The prokineticin system contributes to altered sensitivity in diabetic neuropathy and its inhibition blocked both allodynia and inflammatory events underlying disease
Efficacy of violet–blue light to inactive microbial growth
The increase in health care-associated infections and antibiotic resistance has led to a growing interest
in the search for innovative technologies to solve these problems. In recent years, the interest of
the scientific community has focused on violet–blue light at 405 nm (VBL405). This study aimed to
assess the VBL405 efficiency in reducing microbial growth on surfaces and air. This descriptive study
run between July and October 2020. Petri dishes were contaminated with P. aeruginosa, E. coli, S.
aureus, S. typhimurium, K. pneumoniae and were placed at 2 and 3 m from a LED light source having
a wavelength peak at 405 nm and an irradiance respectively of 967 and 497 μW/cm2. Simultaneously,
the air in the room was sampled for 5 days with two air samplers (SAS) before and after the exposition
to the VBL405 source. The highest microbial reduction was reached 2 m directly under the light source:
S. typhimurium (2.93 log10),
K. pneumoniae (2.30 log10),
S. aureus (3.98 log10),
E. coli (3.83 log10),
P.
aeruginosa (3.86 log10).
At a distance of 3 m from the light source, the greatest reduction was observed
for S. aureus (3.49 log10),
and P. aeruginosa (3.80 log10).
An average percent microbial reduction of
about 70% was found in the sampled air after 12 h of exposure to VBL405. VBL405 has proven to
contrast microbial growth on the plates. Implementing this technology in the environment to provide
continuous disinfection and to control microbial presence, even in the presence of people, may be an
innovative solution
Prokineticin System Is a Pharmacological Target to Counteract Pain and Its Comorbid Mood Alterations in an Osteoarthritis Murine Model
Osteoarthritis (OA) is the most prevalent joint disease associated with chronic pain. OA pain is often accompanied by mood disorders. We addressed the role of the Prokineticin (PK) system in pain and mood alterations in a mice OA model induced with monosodium iodoacetate (MIA). The effect of a PK antagonist (PC1) was compared to that of diclofenac. C57BL/6J male mice injected with MIA in the knee joint were characterized by allodynia, motor deficits, and fatigue. Twenty-eight days after MIA, in the knee joint, we measured high mRNA of PK2 and its receptor PKR1, pro-inflammatory cytokines, and MMP13. At the same time, in the sciatic nerve and spinal cord, we found increased levels of PK2, PKR1, IL-1β, and IL-6. These changes were in the presence of high GFAP and CD11b mRNA in the sciatic nerve and GFAP in the spinal cord. OA mice were also characterized by anxiety, depression, and neuroinflammation in the prefrontal cortex and hippocampus. In both stations, we found increased pro-inflammatory cytokines. In addition, PK upregulation and reactive astrogliosis in the hippocampus and microglia reactivity in the prefrontal cortex were detected. PC1 reduced joint inflammation and neuroinflammation in PNS and CNS and counteracted OA pain and emotional disturbances
Cachrys libanotis L. Extracts: Photocytotoxic Effects on UVA-Irradiated Human Melanoma Cells
Melanoma is the most aggressive form of skin cancer. Photochemotherapy, combining the action of a light source and a chemical photosensitizer, is one of the most interesting current therapeutic approaches. Plants represent a rich source of photoactive compounds, and furanocoumarins are some of the most important naturally occurring phytoconstituents. The aim of this study was to evaluate the photocytotoxic potential of Cachrys libanotis L. (Apiaceae) from Southern Italy. This species belongs to a genus rich in furanocoumarins and widely distributed in Europe. The aerial parts were extracted through both traditional maceration and pressurized cyclic solid-liquid (PCSL) extraction using Naviglio extractor®. Qualitative and quantitative analyses were performed to detect the coumarins content using GC-MS, and the photocytotoxic effects of the extracts were assessed on UVA-irradiated C32 melanoma cells. The apoptotic responses were also evaluated. Furthermore, phenolic content and the in vitro antioxidant potential were also estimated. Xanthotoxin, bergapten and isopimpinellin were identified and quantified. Both extracts affected cell viability in a concentration-dependent manner after irradiation for 1 hour at a dose of 1.08 J/cm2. Sample obtained through PCSL extraction was the most effective, with an IC50 equal to 3.16 μg/mL, a very interesting value if compared with the positive control bergapten. This extract induced up-regulation of apoptotic signals such as BAX and PARP cleavage and, in the presence of UVA radiation, it caused a greater upregulation of p21 protein. Obtained results suggest that investigated species could be a good candidate for further studies aimed to find new drugs with photocytotoxic potential
Circulating mitochondrial DNA is an early indicator of severe illness and mortality from COVID-19
BackgroundMitochondrial DNA (MT-DNA) are intrinsically inflammatory nucleic acids released by damaged solid organs. Whether circulating cell-free MT-DNA quantitation could be used to predict the risk of poor COVID-19 outcomes remains undetermined.MethodsWe measured circulating MT-DNA levels in prospectively collected, cell-free plasma samples from 97 subjects with COVID-19 at hospital presentation. Our primary outcome was mortality. Intensive care unit (ICU) admission, intubation, vasopressor, and renal replacement therapy requirements were secondary outcomes. Multivariate regression analysis determined whether MT-DNA levels were independent of other reported COVID-19 risk factors. Receiver operating characteristic and area under the curve assessments were used to compare MT-DNA levels with established and emerging inflammatory markers of COVID-19.ResultsCirculating MT-DNA levels were highly elevated in patients who eventually died or required ICU admission, intubation, vasopressor use, or renal replacement therapy. Multivariate regression revealed that high circulating MT-DNA was an independent risk factor for these outcomes after adjusting for age, sex, and comorbidities. We also found that circulating MT-DNA levels had a similar or superior area under the curve when compared against clinically established measures of inflammation and emerging markers currently of interest as investigational targets for COVID-19 therapy.ConclusionThese results show that high circulating MT-DNA levels are a potential early indicator for poor COVID-19 outcomes.FundingWashington University Institute of Clinical Translational Sciences COVID-19 Research Program and Washington University Institute of Clinical Translational Sciences (ICTS) NIH grant UL1TR002345
The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and its Implications for Structure Growth
We present new measurements of cosmic microwave background (CMB) lensing over
sq. deg. of the sky. These lensing measurements are derived from the
Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) CMB dataset, which
consists of five seasons of ACT CMB temperature and polarization observations.
We determine the amplitude of the CMB lensing power spectrum at
precision ( significance) using a novel pipeline that minimizes
sensitivity to foregrounds and to noise properties. To ensure our results are
robust, we analyze an extensive set of null tests, consistency tests, and
systematic error estimates and employ a blinded analysis framework. The
baseline spectrum is well fit by a lensing amplitude of
relative to the Planck 2018 CMB power spectra
best-fit CDM model and relative to
the best-fit model. From our lensing power
spectrum measurement, we derive constraints on the parameter combination
of
from ACT DR6 CMB lensing alone and
when combining ACT DR6 and Planck NPIPE
CMB lensing power spectra. These results are in excellent agreement with
CDM model constraints from Planck or
CMB power spectrum measurements. Our lensing measurements from redshifts
-- are thus fully consistent with CDM structure growth
predictions based on CMB anisotropies probing primarily . We find no
evidence for a suppression of the amplitude of cosmic structure at low
redshiftsComment: 45+21 pages, 50 figures. Prepared for submission to ApJ. Also see
companion papers Madhavacheril et al and MacCrann et a
The Atacama Cosmology Telescope: High-resolution component-separated maps across one-third of the sky
Observations of the millimeter sky contain valuable information on a number
of signals, including the blackbody cosmic microwave background (CMB), Galactic
emissions, and the Compton- distortion due to the thermal Sunyaev-Zel'dovich
(tSZ) effect. Extracting new insight into cosmological and astrophysical
questions often requires combining multi-wavelength observations to spectrally
isolate one component. In this work, we present a new arcminute-resolution
Compton- map, which traces out the line-of-sight-integrated electron
pressure, as well as maps of the CMB in intensity and E-mode polarization,
across a third of the sky (around 13,000 sq.~deg.). We produce these through a
joint analysis of data from the Atacama Cosmology Telescope (ACT) Data Release
4 and 6 at frequencies of roughly 93, 148, and 225 GHz, together with data from
the \textit{Planck} satellite at frequencies between 30 GHz and 545 GHz. We
present detailed verification of an internal linear combination pipeline
implemented in a needlet frame that allows us to efficiently suppress Galactic
contamination and account for spatial variations in the ACT instrument noise.
These maps provide a significant advance, in noise levels and resolution, over
the existing \textit{Planck} component-separated maps and will enable a host of
science goals including studies of cluster and galaxy astrophysics, inferences
of the cosmic velocity field, primordial non-Gaussianity searches, and
gravitational lensing reconstruction of the CMB.Comment: The Compton-y map and associated products will be made publicly
available upon publication of the paper. The CMB T and E mode maps will be
made available when the DR6 maps are made publi
The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters
We present cosmological constraints from a gravitational lensing mass map
covering 9400 sq. deg. reconstructed from CMB measurements made by the Atacama
Cosmology Telescope (ACT) from 2017 to 2021. In combination with BAO
measurements (from SDSS and 6dF), we obtain the amplitude of matter
fluctuations at 1.8% precision,
and the Hubble
constant at
1.6% precision. A joint constraint with CMB lensing measured by the Planck
satellite yields even more precise values: ,
and . These measurements agree
well with CDM-model extrapolations from the CMB anisotropies measured
by Planck. To compare these constraints to those from the KiDS, DES, and HSC
galaxy surveys, we revisit those data sets with a uniform set of assumptions,
and find from all three surveys are lower than that from ACT+Planck
lensing by varying levels ranging from 1.7-2.1. These results motivate
further measurements and comparison, not just between the CMB anisotropies and
galaxy lensing, but also between CMB lensing probing on
mostly-linear scales and galaxy lensing at on smaller scales. We
combine our CMB lensing measurements with CMB anisotropies to constrain
extensions of CDM, limiting the sum of the neutrino masses to eV (95% c.l.), for example. Our results provide independent
confirmation that the universe is spatially flat, conforms with general
relativity, and is described remarkably well by the CDM model, while
paving a promising path for neutrino physics with gravitational lensing from
upcoming ground-based CMB surveys.Comment: 30 pages, 16 figures, prepared for submission to ApJ. Cosmological
likelihood data is here:
https://lambda.gsfc.nasa.gov/product/act/actadv_prod_table.html ; likelihood
software is here: https://github.com/ACTCollaboration/act_dr6_lenslike . Also
see companion papers Qu et al and MacCrann et al. Mass maps will be released
when papers are publishe
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