278 research outputs found
Morfometrijsko ispitivanje nabora crevne sluzokože šarana hranjenog različitom dodatnom hranom u poluintenzivnom sistemu
U poluintenzivnom sistemu gajenja šarana u poslednjoj deceniji dolazi do promena u vrsti dodatne hrane koje povećavaju održivost proizvodnje. Sa žitarica koje su se godinama koristile kao dodata hrana, sada se prelazi na peletiranu i ekstrudiranu hranu. Ova zamena uzrokuje i promene u fiziologiji varenja riba, a kao posledica se dešavaju morfološke promene na crevima. Najčešće se na organima za varenje riba gajenih u akvakulturi ne nalaze teže histopatološke promene, pa se pribegava kvantifikaciji i morfometriji histoloških parametara koje mogu da ukažu na odstupanja od normalne građe/funkcije. Metod evaluacije dužine crevnih nabora je korišćen u velikom broju studija koje su se bavile efektima različitih tipova hrane i/ili aditiva na crevo riba. Cilj rada je da se utvrdi efekat različitih tipova hrane (žitarice, peletirana, ekstrudirana hrana) na crevo šarana merenjem dužine crevnih nabora kod riba koje su gajene poluintenzivno. Dužina crevnih nabora je korelisana sa prirastom ribe.
Kretanje dužine crevnih nabora po jezerima/vrsti dodate hrane je imalo pravilan tok (Fig. 1). Najkraći crevni nabori su izmereni kod riba hranjenih žitaricama. U sva tri jezera primetan je pad dužine nabora u junu. U ovom mesecu su vrednosti najmanje, manje čak i od inicijalnih na početku eksperimenta (u aprilu), kao i vrednosti dobijenih u maju. Od juna dužina nabora creva konstantno raste kod riba u svim jezerima, bez obzira na tip dodate hrane.
Rezultati su pokazali visok stepen statistički značajne korelacije između mase tela ribe i dužine crevnih nabora u svim jezerima (Tab. 2). Ukoliko se posmatraju pojedinačna jezera, vrednosti se kreću između 0.82 kod riba hranjenih peletiranom hranom, preko 0.83 kod riba hranjenih žitaricama do 0.86 kod riba hranjenih ekstrudiranom hranom. Dužina crevnih nabora je koristan parametar u eksperimentima ishrane riba i često se primenjuje u proceni efekta određene hrane na crevo riba. Smanjenje dužine nabora može da ukaže na pojavu enteritisa, na nedovoljnu ishranu ili gladovanje. Naši rezultati pokazuju pozitivnu korelaciju između mase tela ribe i dužine crevnih nabora. Oni su u skladu i sa sličnim istraživanjima koja su sprovedena na drugim životinjskim vrstama, mahom na domaćim životinjama. Crevni nabori na početku eksperimenta ne rastu, čak pokazuju trend pada sve do juna meseca i to iako ribe pokazuju konstantan prirast u svim jezerima, što se objašnjava količinom prirodne hrane koja je u to doba najveća u jezerima. Naime, na osnovu analize prirodne hrane tokom ovog perioda možemo videti da postoji velika biomasa zooplanktona u toku aprila, maja i juna dok je zoobentos na niskom nivou u svim jezerima u toku celog eksperimenta i ne prelazi 10 g/m2. Ovo uzrokuje promene u načinu ishrane ribe od juna meseca. Do tada se šaran hranio uglavnom zooplanktonom, koga je bilo u izobilju, a nakon toga, početkom juna, zbog nedostatka prirodne hrane,riba počinje da sve više konzumira dodatu, što uzrokuje i povećanje dužine crevnih nabora, s obzirom da su pelete, kojom se ribe hrane voluminoznije i većih dimenzija od zooplanktona. Hranjenjem, ribe pune creva i samim tim ih i šire, što omogućava povećanje apsorpcione površine povećanjem dužine crevnih nabora. Ovaj fenomen u stvari predstavlja adaptaciju creva na različite tipove hrane kod riba.
Naše istraživanje je pokazalo da praćenje histologije šarana može da ukaže kako se odvija proces varenja zavisno od dela sezone/razvoja zajednice zooplanktona, ali i vrste dodate hrane u poluintenzivnom sistemu
Multidisciplinary Approach in the Implementation of ATL Methods in Teaching of Animal Sciences I. Presentation of Scenarios
One of the problems Serbian HE faces is summing up of knowledge thaught in different courses and its application in real life by professional decision making. In order to give an example of possibilities of interactive teaching methodology and contribute to the transformation of students from knowledge recipients to knowledge co-constructors, a set of scenarios for a multidisciplinary approach in teaching/learning is presented. The set consists of 4 scenarios for knowledge refreshment followed by a final workshop – a debate similar to the real life situation. A multidisciplinary approach to the topic of aquaculture development, water and fish quality in aquaculture is presented in this case. By participating interactive classes and a debate, 4 year students in animal sciences work in groups to exercise solving problems, to make professional decision, and develop other professional and generic skills. This paper presents the result of the process of development o scenarios for such exercise and results of the exercise will be presented in another paper (Part 2)
Superconductivity, phase fluctuations and the c-axis conductivity of bilayer high temperature superconductors
We present a theory of the interplane conductivity of bilayer high
temperature superconductors, focusing on the effect of quantal and thermal
fluctuations on the oscillator strengths of the superfluid stiffness and the
bilayer plasmon. We find that the opening of the superconducting gap and
establishment of superconducting phase coherence each lead to redistribution of
spectral weight over wide energy scales. The factor-of-two relation between the
superfluid stiffness and the change below in the oscillator strength of
the absorptive part of the conductivity previously derived for single-layer
systems, is found to be substantially modified in bilayer systems.Comment: 11 pages, 14 figure
Correlation between the Josephson coupling energy and the condensation energy in bilayer cuprate superconductors
We review some previous studies concerning the intra-bilayer Josephson
plasmons and present new ellipsometric data of the c-axis infrared response of
almost optimally doped Bi_{2}Sr_{2}CaCu_{2}O_{8}. The c-axis conductivity of
this compound exhibits the same kind of anomalies as that of underdoped
YBa_{2}Cu_{3}O_{7-delta}. We analyze these anomalies in detail and show that
they can be explained within a model involving the intra-bilayer Josephson
effect and variations of the electric field inside the unit cell. The Josephson
coupling energies of different bilayer compounds obtained from the optical data
are compared with the condensation energies and it is shown that there is a
reasonable agreement between the values of the two quantities. We argue that
the Josephson coupling energy, as determined by the frequency of the
intra-bilayer Josephson plasmon, represents a reasonable estimate of the change
of the effective c-axis kinetic energy upon entering the superconducting state.
It is further explained that this is not the case for the estimate based on the
use of the simplest ``tight-binding'' sum rule. We discuss possible
interpretations of the remarkable agreement between the Josephson coupling
energies and the condensation energies. The most plausible interpretation is
that the interlayer tunneling of the Cooper pairs provides the dominant
contribution to the condensation energy of the bilayer compounds; in other
words that the condensation energy of these compounds can be accounted for by
the interlayer tunneling theory. We suggest an extension of this theory, which
may also explain the high values of T_{c} in the single layer compounds
Tl_{2}Ba_{2}CuO_{6} and HgBa_{2}CuO_{4}, and we make several experimentally
verifiable predictions.Comment: 16 pages (including Tables) and 7 figures; accepted for publication
in Physical Review
Differential requirements for actin during yeast and mammalian endocytosis
Key features of clathrin-mediated endocytosis have been conserved across evolution. However, endocytosis in Saccharomyces cerevisiae is completely dependent on a functional actin cytoskeleton, whereas actin appears to be less critical in mammalian cell endocytosis. We reveal that the fundamental requirement for actin in the early stages of yeast endocytosis is to provide a strong framework to support the force generation needed to direct the invaginating plasma membrane into the cell against turgor pressure. By providing osmotic support, pressure differences across the plasma membrane were removed and this reduced the requirement for actin-bundling proteins in normal endocytosis. Conversely, increased turgor pressure in specific yeast mutants correlated with a decreased rate of endocytic patch invagination
Penetration of Josephson vortices and measurement of the c-axis penetration depth in : Interplay of Josephson coupling, surface barrier and defects
The first penetration field H_{J}(T) of Josephson vortices is measured
through the onset of microwave absorption in the locked state, in slightly
overdoped single crystals (T_{c} ~ 84
K). The magnitude of H_{J}(T) is too large to be accounted for by the first
thermodynamic critical field H_{c1}(T). We discuss the possibility of a
Bean-Livingston barrier, also supported by irreversible behavior upon flux
exit, and the role of defects, which relates H_{J}(T) to the c-axis penetration
depth . The temperature dependence of the latter, determined by
a cavity perturbation technique and a theoretical estimate of the
defect-limited penetration field are used to deduce from H_{J}(T) the absolute
value of .Comment: 9 pages, 6 figure
Influence of Chemical Structure on the Stability and Conductance of Porphyrin Single-Molecule Junctions
Quantum Matter and Optic
Decoupling of a Current-Biased Intrinsic Josephson Junction from its Environment
We have observed a dissipative phase diffusion branch in arrays of hysteretic
high-Tc intrinsic Josephson junctions. By comparing the data with a thermal
activation model we extract the impedance seen by the junction in which phase
diffusion is occurring. At the plasma frequency this junction is isolated from
its environment and it sees its own large (~ kilo Ohm) impedance. Our results
suggest that stacks of Josephson junctions may be used for isolation purposes
in the development of a solid state quantum computer
Expression and subcellular localization of cyclin D1 protein in epithelial ovarian tumour cells
The expression of cyclin D1 protein in tumour sections from 81 patients with epithelial ovarian cancer was analysed using immunohistochemistry. The tumours that overexpressed cyclin D1 in more than 10% of neoplastic cells were considered positive. Thus overexpression of cyclin D1 was observed in 72/81 (89%) of the cases examined. Protein was detected in both the nucleus and the cytoplasm in 24/81 (30%) and localized exclusively in the cytoplasm in 48/81 (59%) of the tumours. Cyclin D1 was overexpressed in both borderline and invasive tumours. There was no association between protein overexpression and tumour stage and differentiation. Furthermore, no correlation between cyclin D1 expression and clinical outcome was observed. However, in tumours overexpressing cyclin D1 (n = 72), the proportion displaying exclusively cytoplasmic localization of protein was higher in those with serous compared with non-serous histology (P = 0.004, odds ratio 4.8, 95% confidence interval 1.4–19.1). Western analysis using a monoclonal antibody to cyclin D1 identified a 36 kDa protein in homogenates from seven tumours displaying cytoplasmic only and one tumour demonstrating both nuclear and cytoplasmic immunostaining. Using restriction fragment length polymorphism polymerase chain reaction and PCR-multiplex analysis, amplification of the cyclin D1 gene (CCNDI) was detected in 1/29 of the tumours demonstrating overexpression of cyclin D1 protein. We conclude that deregulation of CCND1 expression leading to both cytoplasmic and nuclear protein localization is a frequent event in ovarian cancer and occurs mainly in the absence of gene amplification. © 1999 Cancer Research Campaig
Interferon and B-cell Signatures Inform Precision Medicine in Lupus Nephritis
Introduction: Current therapeutic management of lupus nephritis (LN) fails to induce long-term remission in over 50% of patients, highlighting the urgent need for additional options. Methods: We analyzed differentially expressed genes (DEGs) in peripheral blood from patients with active LN (n = 41) and active nonrenal lupus (n = 62) versus healthy controls (HCs) (n = 497) from the European PRECISESADS project (NTC02890121), and dysregulated gene modules in a discovery (n = 26) and a replication (n = 15) set of active LN cases. Results: Replicated gene modules qualified for correlation analyses with serologic markers, and regulatory network and druggability analysis. Unsupervised coexpression network analysis revealed 20 dysregulated gene modules and stratified the active LN population into 3 distinct subgroups. These subgroups were characterized by low, intermediate, and high interferon (IFN) signatures, with differential dysregulation of the “B cell” and “plasma cells/Ig” modules. Drugs annotated to the IFN network included CC-motif chemokine receptor 1 (CCR1) inhibitors, programmed death-ligand 1 (PD-L1) inhibitors, and irinotecan; whereas the anti-CD38 daratumumab and proteasome inhibitor bortezomib showed potential for counteracting the “plasma cells/Ig” signature. In silico analysis demonstrated the low-IFN subgroup to benefit from calcineurin inhibition and the intermediate-IFN subgroup from B-cell targeted therapies. High-IFN patients exhibited greater anticipated response to anifrolumab whereas daratumumab appeared beneficial to the intermediate-IFN and high-IFN subgroups. Conclusion: IFN upregulation and B and plasma cell gene dysregulation patterns revealed 3 subgroups of LN, which may not necessarily represent distinct disease phenotypes but rather phases of the inflammatory processes during a renal flare, providing a conceptual framework for precision medicine in LN. © 2024 International Society of Nephrolog
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