166 research outputs found
Expansion of elevational range in a forest pest: Can parasitoids track their hosts?
We are thankful to Karim Senhadji and Ramon Ruiz-Puche for their help during the field work, and to Sara Garcia Morato for her contribution to quantifying rates of parasitism in PPM clutches at the laboratory. Two anonymous referees contributed to improve the manuscript. This study was supported by projects PROPINOL (PN22/2008), GESBOME (P06-RNM-1890) from Junta de Andalucia, REMEDINAL TE-CM (S2018/EMT-4338) from Comunidad de Madrid, ADAPTAMED (LIFE14 CCA/ES/000612) from LIFE program, and GILES (PCIN-2016-150) from the ERANET-LAC H2020 Programme.Gradients in elevation impose changes in environmental conditions, which in turn modulate species distribution and abundance as well as the interactions they maintain. Along the gradient, interacting species (e.g., predators, parasitoids) can respond to changes in different ways. This study aims to investigate how egg parasitism of a forest pest, the pine processionary moth (PPM), Thaumetopoea pityocampa, vary along an elevational gradient (190-2000 m.a.s.l.) in a mountain range of SE Spain, including areas of recent elevational expansion, for a seven years period (2008-2014). We used generalized linear mixed models to ascertain the effect of both elevation and the winter North Atlantic Oscillation (NAO) index (a proxy of interannual climatic conditions) on the rate of parasitism, and the occurrence probabilities of two parasitoid species: a PPM specialist and a generalist species. Since four pine species are stratified along the elevational gradient, we repeated all the analyses separately for lowlands (190-1300 m. a.s.l.) and uplands (1350-2000 m. a.s.l.). Results showed a decrease in both parasitism rate and probability of occurrence of the two main parasitoid species with elevation, although decline was more severe for the specialist species. The effect of elevation was more conspicuous and intense in uplands than in lowlands. Positive NAO winter values, associated with cold and dry winters, reduced the rate of parasitism and the probability of occurrence of the two main parasitoid species-but particularly for the generalist species-as elevation increases. In a context of climate warming, it is crucial to mitigate PPM elevational and latitudinal expansion. Increasing tree diversity at the PPM expansion areas may favor the establishment of parasitoids, which could contribute to synchronizing host- parasitoid interactions and minimize the risk of PPM outbreaks.Junta de Andalucia
PN22/2008REMEDINAL TE-CM from Comunidad de Madrid
S2018/EMT-4338ADAPTAMED from LIFE program
LIFE14 CCA/ES/000612GILES from the ERANET-LAC H2020 Programme
PCIN-2016-150Junta de Andalucia
P06-RNM-189
Vibrational circular dichroism signature of hemiprotonated intercalated four-stranded i-DNA
Abstract The four-stranded intercalated DNA structure exemplified by the oligonucleotide 5V-d(CCCCCCCCCCCC) (d(C) 12 ) was studied at acidic pH by infrared absorption (IR) and vibrational circular dichroism (VCD) spectroscopy and compared with spectra of the same oligonucleotide at neutral pH to establish distinct VCD markers for the intercalation motif. The most striking feature is a new absorption at 1694 cm À 1 and its corresponding VCD couplet with reversed sign. These are unique for the intercalated structure and have not been observed for other parallel stranded duplexes. Significant characteristic features resulting from the spatial arrangement of the sugar-phosphate backbone are also clearly present for d(C) 12 at acidic pH. An extensive network of CH. . .O bonds twists the backbone such that multiple through-space vibrational coupling occurs among neighbouring sugar-phosphate residues resulting in unusual VCD signals.
Verification of the causes of glaciations and sea level changes using the records of calcite speleothems
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Epigenomics and Chromatin Dynamics
A report of the 'Joint Keystone Symposium on Epigenomics and Chromatin Dynamics', Keystone, Colorado, 17-22 January 2012. This year's Joint Keystone Symposium on Epigenomics and Chromatin Dynamics was one of the largest Keystone meetings to date, reflecting the excitement and many developments in this area. Richard Young opened the meeting by giving a historic overview before sharing more detailed insights from his recent work in describing the role of the lysine demethylase Lsd1 in mouse embryonic stem (ES) cell differentiation. He also set the broader stage and highlighted the excitement concerning recent advances in epigenetic drugs such as the new bromodomain inhibitors.Stem Cell and Regenerative Biolog
Genetic diversity and host alternation of the egg parasitoid Oencyrtus pityocampae between the pine processionary moth and caper bug
Research ArticleThe increased use of molecular tools for species identification in recent decades revealed
that each of many apparently generalist parasitoids are actually a complex of morphologically
similar congeners, most of which have a rather narrow host range. Ooencyrtus pityocampae
(OP), an important egg parasitoid of the pine processionary moth (PPM), is
considered a generalist parasitoid. OP emerges from PPM eggs after winter hibernation,
mainly in spring and early summer, long before the eggs of the next PPM generation occurs.
The occurrence of OP in eggs of the variegated caper bug (CB) Stenozygum coloratum in
spring and summer suggests that OP populations alternate seasonally between PPM and
CB. However, the identity of OP population on CB eggs seemed uncertain; unlike OP-PPM
populations, the former displayed apparently high male/female ratios and lack of attraction
to the PPM sex pheromone. We studied the molecular identities of the two populations
since the morphological identification of the genus Ooencyrtus, and OP in particular, is difficult.
Sequencing of COI and ITS2 DNA fragments and AFLP analysis of individuals from
both hosts revealed no apparent differences between the OP-PPM and the OP-CB populations
for both the Israeli and the Turkish OPs, which therefore supported the possibility of
host alternation. Sequencing data extended our knowledge of the genetic structure of OP
populations in the Mediterranean area, and revealed clear separation between East and
West Mediterranean populations. The overall level of genetic diversity was rather small,
with the Israeli population much less diverse than all others; possible explanations for this
finding are discussed. The findings support the possibility of utilizing the CB and other hosts
for enhancing biological control of the PPMinfo:eu-repo/semantics/publishedVersio
Inhibition of 26S Protease Regulatory Subunit 7 (MSS1) Suppresses Neuroinflammation
Recently, researchers have focused on immunosuppression induced by rifampicin. Our previous investigation found that rifampicin was neuroprotective by inhibiting the production of pro-inflammatory mediators, thereby suppressing microglial activation. In this study, using 2-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS), we discovered that 26S protease regulatory subunit 7 (MSS1) was decreased in rifampicin-treated microglia. Western blot analysis verified the downregulation of MSS1 expression by rifampicin. As it is indicated that the modulation of the ubiquitin-26S proteasome system (UPS) with proteasome inhibitors is efficacious for the treatment of neuro-inflammatory disorders, we next hypothesized that silencing MSS1 gene expression might inhibit microglial inflammation. Using RNA interference (RNAi), we showed significant reduction of IkBα degradation and NF-kB activation. The production of lipopolysaccharides-induced pro-inflammatory mediators such as inducible nitric oxide synthase (iNOS), nitric oxide, cyclooxygenase-2, and prostaglandin E2 were also reduced by MSS1 gene knockdown. Taken together, our findings suggested that rifampicin inhibited microglial inflammation by suppressing MSS1 protein production. Silencing MSS1 gene expression decreased neuroinflammation. We concluded that MSS1 inhibition, in addition to anti-inflammatory rifampicin, might represent a novel mechanism for the treatment of neuroinflammatory disorders
Ultraweak excitations of the quantum vacuum as physical models of gravity
It has been argued by several authors that the space-time curvature observed
in gravitational fields, and the same idea of forms of physical equivalence
different from the Lorentz group, might emerge from the dynamical properties of
the physical flat-space vacuum in a suitable hydrodynamic limit. To explore
this idea, one could start by representing the physical vacuum as a Bose
condensate of elementary quanta and look for vacuum excitations that, on a
coarse grained scale, resemble the Newtonian potential. In this way, it is
relatively easy to match the weak-field limit of classical General Relativity
or of some of its possible variants. The idea that Bose condensates can provide
various forms of gravitational dynamics is not new. Here, I want to emphasize
some genuine quantum field theoretical aspects that can help to understand i)
why infinitesimally weak, 1/r interactions can indeed arise from the same
physical vacuum of electroweak and strong interactions and ii) why, on a
coarse-grained scale, their dynamical effects can be re-absorbed into an
effective curved metric structure.Comment: 30 pages, no figures, accepted by Classical and Quantum Gravit
Characterisation and performance of the PADME electromagnetic calorimeter
The PADME experiment at the LNF Beam Test Facility searches for dark photons produced in the annihilation of positrons with the electrons of a fixed target. The strategy is to look for the reaction e+ + e− → γ + A0, where A0 is the dark photon, which cannot be observed directly or via its decay products. The electromagnetic calorimeter plays a key role in the experiment by measuring the energy and position of the final-state γ. The missing four-momentum carried away by the A0 can be evaluated from this information and the particle mass inferred. This paper presents the design, construction, and calibration of the PADME’s electromagnetic calorimeter. The results achieved in terms of equalisation, detection efficiency and energy resolution during the first phase of the experiment demonstrate the effectiveness of the various tools used to improve the calorimeter performance with respect to earlier prototypes
The Disequilibrium of Nucleosomes Distribution along Chromosomes Plays a Functional and Evolutionarily Role in Regulating Gene Expression
To further understand the relationship between nucleosome-space occupancy (NO) and global transcriptional activity in mammals, we acquired a set of genome-wide nucleosome distribution and transcriptome data from the mouse cerebrum and testis based on ChIP (H3)-seq and RNA-seq, respectively. We identified a nearly consistent NO patterns among three mouse tissues—cerebrum, testis, and ESCs—and found, through clustering analysis for transcriptional activation, that the NO variations among chromosomes are closely associated with distinct expression levels between house-keeping (HK) genes and tissue-specific (TS) genes. Both TS and HK genes form clusters albeit the obvious majority. This feature implies that NO patterns, i.e. nucleosome binding and clustering, are coupled with gene clustering that may be functionally and evolutionarily conserved in regulating gene expression among different cell types
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