3,812 research outputs found
Pathological and histopatnotogical studies of the swimbladder of eels Anguilla anguitla infected by Angutlticpta crassus (Nemafoda: Dracuncuioidea)
The swimbladder lesions produced by Anguillicola crassus (Nematoda) infection, causing mass mortality among eels in Lake Balaton (Hungary) were studied by histological methods. In the initial phase of infection, no severe changes developed in the swimbladder wall despite the presence and intensive blood-sucking activity of worms that filled the lumen of the swimbladder. After disruption of the worms and primarily because of repeated reinfection by larvae, however, the wall of the swimblaader markedly thickened and showed degenerative, inflammatory and proliferative changes. Acute processes were characterized by epithelial hyperplasia and hyperaemia of the swimbladder wall. In cases of chronic swimbladder inflammation, oedema and hyperplasia of tissues of the tunica propria, submucosa and serosa could be observed, as well as granulomatoid infiltration by mononuclear cells and fibrinoid degeneration around the larvae
European studies: Taking stock and looking ahead
This essay is an attempt to generalize experiences of Central and Eastern European universities in the field of European Studies over the past 20 years. The paper follows the logic of business analysis in order to come up with proposals for future action
The biological basis and clinical significance of hormonal imprinting, an epigenetic process
The biological phenomenon, hormonal imprinting, was named and defined by us (Biol Rev, 1980, 55, 47-63) 30 years ago, after many experimental works and observations. Later, similar phenomena were also named to epigenetic imprinting or metabolic imprinting. In the case of hormonal imprinting, the first encounter between a hormone and its developing target cell receptor—usually at the perinatal period—determines the normal receptor-hormone connection for life. However, in this period, molecules similar to the target hormone (members of the same hormone family, synthetic drugs, environmental pollutants, etc), which are also able to bind to the receptor, provoke faulty imprinting also with lifelong—receptorial, behavioral, etc.,—consequences. Faulty hormonal imprinting could also be provoked later in life in continuously dividing cells and in the brain. Faulty hormonal imprinting is a disturbance of gene methylation pattern, which is epigenenetically inherited to the further generations (transgenerational imprinting). The absence of the normal or the presence of false hormonal imprinting predispose to or manifested in different diseases (e.g., malignant tumors, metabolic syndrome) long after the time of imprinting or in the progenies
First results with the boloSource() algorithm: Photometry of faint standard stars observed by Herschel/PACS
The boloSource() algorithm is a tool to separate the signal of compact
sources from that of the diffuse background in the timeline of far-infrared
measurements performed by the PACS camera of the Herschel Space Observatory. An
important characteristic and quality indicator of this method is that how well
it can reproduce the flux of faint standard stars which have reliable flux
estimates. For this propose we selected a few calibrator targets and
constructed light curves by extracting point source flux for each repetition of
the measurements independently using standard aperture photometry methods.
These were compared with the light curves obtained using the boloSource()
method on the same dataset. The results indicate that boloSource() provides a
similar level of photometric accuracy and reproducibility as the usual flux
extraction and photometry methods. This new technique will be developed further
and also tested against other methods in more complex fields with the goal to
make it usable for large-scale studies in the future.Comment: 10 pages, 7 figures, 4 table
High Resolution Valley Spectroscopy of Si Quantum Dots
We study an accumulation mode Si/SiGe double quantum dot (DQD) containing a
single electron that is dipole coupled to microwave photons in a
superconducting cavity. Measurements of the cavity transmission reveal
dispersive features due to the DQD valley states in Si. The occupation of the
valley states can be increased by raising temperature or applying a finite
source-drain bias across the DQD, resulting in an increased signal. Using
cavity input-output theory and a four-level model of the DQD, it is possible to
efficiently extract valley splittings and the inter- and intra-valley tunnel
couplings
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