4,114 research outputs found
Almost isomorphism for countable state Markov shifts
Countable state Markov shifts are a natural generalization of the well-known
subshifts of finite type. They are the subject of current research both for
their own sake and as models for smooth dynamical systems. In this paper, we
investigate their almost isomorphism and entropy conjugacy and obtain a
complete classification for the especially important class of strongly positive
recurrent Markov shifts. This gives a complete classification up to entropy
conjugacy of the natural extensions of smooth entropy expanding maps, including
all smooth interval maps with non-zero topological entropy
Good potentials for almost isomorphism of countable state Markov shifts
Almost isomorphism is an equivalence relation on countable state Markov
shifts which provides a strong version of Borel conjugacy; still, for mixing
SPR shifts, entropy is a complete invariant of almost isomorphism. In this
paper, we establish a class of potentials on countable state Markov shifts
whose thermodynamic formalism is respected by almost isomorphism
Tracing out the Northern Tidal Stream of the Sagittarius Dwarf Spheoridal Galaxy
The main aim of this paper is to report two new detections of tidal debris in
the northern stream of the Sagittarius dwarf galaxy located at 45 arcdeg and 55
arcdeg from the center of galaxy. Our observational approach is based on deep
color-magnitude diagrams, that provides accurate distances, surface brightness
and the properties of stellar population of the studied region of this tidal
stream. The derived distances for these tidal debris wraps are 45 kpc and 54
kpc respectively.We also confirm these detections with numerical simulations of
the Sagittarius dwarf plus the Milky Way. The model reproduces the present
position and velocity of the Sagittarius main body and presents a long tidal
stream formed by tidal interaction with the Milky Way potential. This model is
also in good agreement with the available observations of the Sagittarius tidal
stream. We also present a method for estimating the shape of the Milky Way halo
potential using numerical simulations. From our simulations we obtain an
oblateness of the Milky Way dark halo potential of 0.85, using the current
database of distances and radial velocities of the Sagittarius tidal stream.
The color-magnitude diagram of the apocenter of Sagittarius shows that this
region of the stream shares the complex star formation history observed in the
main body of the galaxy. We present the first evidence for a gradient in the
stellar population along the stream, possibly correlated with its different
pericenter passages. (abridged)Comment: 43 pages (including 15 figures; for high resolution color figures,
please contact [email protected]). Submitted to Ap
Valorisation Potential of Invasive Acacia dealbata, A. longifolia and A. melanoxylon from Land Clearings
Acacia spp. are invasive in Southern Europe, and their high propagation rates produce excessive biomass, exacerbating wildfire risk. However, lignocellulosic biomass from Acacia spp. may be utilised for diverse biorefinery applications. In this study, attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR), high-performance anion-exchange chromatography pulsed amperometric detection (HPAEC-PAD) and lignin content determinations were used for a comparative compositional characterisation of A. dealbata, A. longifolia and A. melanoxylon. Additionally, biomass was treated with three white-rot fungi species ( Ganoderma lucidum, Pleurotus ostreatus and Trametes versicolor), which preferentially degrade lignin. Our results showed that the pre-treatments do not significantly alter neutral sugar composition while reducing lignin content. Sugar release from enzymatic saccharification was enhanced, in some cases possibly due to a synergy between white-rot fungi and mild alkali pretreatments. For example, in A. dealbata stems treated with alkali and P. ostreatus, saccharification yield was 702.3 nmol mg -1, which is higher than the samples treated only with alkali (608.1 nmol mg -1), and 2.9-fold higher than the non-pretreated controls (243.9 nmol mg -1). By characterising biomass and pretreatments, generated data creates value for unused biomass resources, contributing to the implementation of sustainable biorefining systems. In due course, the generated value will lead to economic incentives for landowners to cut back invasive Acacia spp. more frequently, thus reducing excess biomass, which exacerbates wildfire risk
Biorefining Potential of Wild-Grown Arundo donax, Cortaderia selloana and Phragmites australis and the Feasibility of White-Rot Fungi-Mediated Pretreatments
Arundo donax, Cortaderia selloana and Phragmites australis are high-biomass-producing perennial Poalean species that grow abundantly and spontaneously in warm temperate regions, such as in Mediterranean-type climates, like those of Southern Europe, Western United States coastal areas, or in regions of South America, South Africa and Australia. Given their vigorous and spontaneous growth, biomass from the studied grasses often accumulates excessively in unmanaged agro-forestry areas. Nonetheless, this also creates the demand and opportunity for the valorisation of these biomass sources, particularly their cell wall polymers, for biorefining applications. By contrast, a related crop, Miscanthus × giganteus, is a perennial grass that has been extensively studied for lignocellulosic biomass production, as it can grow on low-input agricultural systems in colder climates. In this study Fourier transform mid-infrared spectroscopy (FTIR), high-performance anion-exchange chromatography (HPAEC) and lignin content determinations were used for a comparative compositional characterisation of A. donax, C. selloana and P. australis harvested from the wild, in relation to a trial field-grown M. × giganteus high-yielding genotype. A high-throughput saccharification assay showed relatively high sugar release values from the wild-grown grasses, even with a 0.1M NaOH mild alkali pretreatment. In addition to this alkaline pretreatment, biomass was treated with white-rot fungi (WRF), which preferentially degrade lignin more readily than holocellulose. Three fungal species were used: Ganoderma lucidum, Pleurotus ostreatus and Trametes versicolor. Our results showed that neutral sugar contents are not significantly altered, while some lignin is lost during the pretreatments. Furthermore, sugar release upon enzymatic saccharification was enhanced, and this was dependent on the plant biomass and fungal species used in the treatment. To maximise the potential for lignocellulose valorisation, the liquid fractions from the pretreatments were analysed by high performance liquid chromatography – photodiode array detection – electrospray ionisation tandem mass spectrometry (HPLC-PDA-ESI-MS(n)). This study is one of the first to report on the composition of WRF-treated grass biomass, while assessing the potential relevance of breakdown products released during the treatments, beyond more traditional sugar-for-energy applications. Ultimately, we expect that our data will help promote the valorisation of unused biomass resources, create economic value, while contributing to the implementation of sustainable biorefining systems
Reduced expression of mir15a in the blood of patients with oral squamous cell carcinoma is associated with tumor staging
MicroRNAs (miRNAs) mirl 5a and let7a are iMportant regulators of bcl-2, ras and c-myc proteins Considering that these miRNAs are commonly altered in many human cancers and that these proteins are reported to be altered in oral squamous cell carcinoma (OSCC), we investigated them in a set of OSCC cases \u27I he miRNAs as well as the proteins were evaluated in the tumor and blood of 20 patients by real-time quantitative PCR and iMmunohistochemistry, respectively The expression of nfirl5a and bcl-2 proteins in the tumors was not associated with each other or with tumor staging On the other hand, we found reduced expression of this miRNA in the blood of patients with an advanced stage of OSCC and with lymph node metastasis The expression of let7a in the tumor and blood was not associated with tumor size lymph node metastasis, tumor staging and immunoexpression of ras and c-myc proteins In conclusion, the present study shows that reduced expression of Mir15a is associated with OSCC stagin
Controlling the crystalline and magnetic texture in sputtered Fe 0.89 Ga 0.11 thin films: Influence of substrate and thermal treatment
In this work we present a careful study on the relationship between the magnetic and structural properties of a highly magnetostrictive Fe0.89Ga0.11 (Fe-Ga) alloy deposited onto glass, Si and MgO substrates. When grown on glass, the films are polycrystalline with randomly oriented grains without any texture, while the ones on Si and MgO present preferred growth directions. Fe-Ga/Si films show a [1 1 3] fibre-like texture, and Fe-Ga/MgO presents a quasi monocrystalline behavior with the (1 0 0) film plane direction parallel to the substrate surface. When Fe-Ga/MgO films are annealed an additional (1 1 0) texture is also observed. Magnetometry and ferromagnetic resonance (FMR) show that the magnetic behavior is closely related to the structural observed textures. Furthermore, the structural analysis allowed us to get a deeper understanding of the magnetic behavior. This point is very important to get the ability of controlling the crystalline texture by means of growing onto different substrates and/or thermal treatments, which in turns opens the possibility of handling the magnetic texture which is particularly important in magnetostrictive materials for electronic devices.Fil: Ramírez Chamorro, Gerardo Alexis. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología; ArgentinaFil: Malamud, Florencia. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Gomez, Javier Enrique. Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología; ArgentinaFil: Rodríguez, Luis M.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Fregenal, Daniel Eduardo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Butera, Alejandro Ricardo. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología; ArgentinaFil: Milano, Julian. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología; Argentin
Angular moments of the decay Λb 0 → Λμ + μ − at low hadronic recoil
An analysis of the angular distribution of the decay Λ0 b → Λµ +µ − is presented, using data collected with the LHCb detector between 2011 and 2016 and corresponding to an integrated luminosity of approximately 5 fb−1 . Angular observables are determined using a moment analysis of the angular distribution at low hadronic recoil, corresponding to the dimuon invariant mass squared range 15 < q2 < 20 GeV2/c4 . The full basis of observables is measured for the first time. The lepton-side, hadron-side and combined forward-backward asymmetries of the decay are determined to b
Biological variation in HbA1c predicts risk of retinopathy and nephropathy in type 1 diabetes
WSTĘP. Autorzy niniejszej pracy założyli, że ryzyko powikłań mikronaczyniowych
w badaniu Diabetes Control and Complications Trial (DCCT) jest uwarunkowane zarówno
zmiennością hemoglobiny glikowanej (HbA1c), zależną od średniego stężenia glukozy
we krwi (MBG, mean blood glucose), jak i biologiczną zmiennością osobniczą HbA1c.
MATERIAŁ I METODY. Wartości MBG i HbA1c, oznaczone u uczestników badania
DCCT (n = 1441) podczas wizyt odbywających się co 3 miesiące, poddano analizie
według modelu liniowej regresji wieloczynnikowej. W celu oceny zmienności biologicznej
podczas każdej wizyty obliczono indeks glikacji hemoglobiny (HGI, hemoglobin glycation index = wartość zmierzona HbA1c– wartość przewidywana HbA1c), aby ocenić biologiczną
zmienność, opierając się na kierunkowych odchyleniach zmierzonej HbA1c od wartości
przewidywanej na podstawie MBG. Populację podzielono w zależności od średnich
wartości HGI podczas trwania badania na 3 części: o wysokim, średnim i niskim
HGI. Dla poszczególnych grup przeprowadzono analizę z zastosowaniem modelu proporcjonalnego
hazardu Coxa w celu porównania ryzyka wystąpienia oraz rozwoju retinopatii i nefropatii
w zależności od MBG, wieku, sposobu leczenia, grupy prewencji pierwotnej lub interwencji
i czasu trwania cukrzycy.
WYNIKI. Współczynnik prawdopodobieństwa oraz analizy
HGI w testach t podważają twierdzenie, że wartość HbA1c zależy jedynie od MBG.
Podczas 7-letniej obserwacji u pacjentów z wysokimi wartościami HbA1c (wyższymi
niż oczekiwane) było 3-krotnie wyższe ryzyko retinopatii (30 vs. 9%; p < 0,001)
i 6-krotnie wyższe ryzyko nefropatii (6 vs. 1%, p < 0,001) w porównaniu z grupą
o niskim HGI.
WNIOSKI. Osobnicza biologiczna zmienność HbA1c, odmienna i niezależna od
zmienności HbA1c warunkowanej średnią glikemią, występuje niewątpliwie u chorych
na cukrzycę typu 1 biorących udział w badaniu DCCT. Ponadto jest silnym czynnikiem
ryzyka rozwoju cukrzycy. Określenie procesów odpowiedzialnych za biologiczną zmienność
HbA1c mogłoby prowadzić do stworzenia nowych kierunków leczenia hipoglikemizującego
oraz opóźniającego powikłania i postęp choroby.INTRODUCTION. We hypothesized that biological
variation in HbA1c, distinct from variation attributable
to mean blood glucose (MBG), would predict risk
for microvascular complications in the Diabetes Control
and Complications Trial (DCCT).
MATERIAL AND METHODS. A longitudinal multiple
regression model was developed from MBG and
HbA1c measured in the 1,441 DCCT participants at
quarterly visits. A hemoglobin glycation index (HGI
= observed HbA1c–predicted HbA1c) was calculated
for each visit to assess biological variation based on
the directional deviation of observed HbA1c from that
predicted by MBG in the model. The population was
subdivided by thirds into high-, moderate-, and low-
HGI groups based on mean participant HGI during
the study. Cox proportional hazard analysis compared
risk for development or progression of retinopathy
and nephropathy between HGI groups controlled
for MBG, age, treatment group, strata, and
duration of diabetes.
RESULTS. Likelihood ratio and t tests on HGI rejected
the assumption that HbA1c levels were determined
by MBG alone. At 7 years’ follow-up, patients in
the high-HGI group (higher than-predicted HbA1c)
had three times greater risk of retinopathy (30 vs.
9%; P < 0.001) and six times greater risk of nephropathy
(6 vs. 1%; P < 0.001) compared with the low-
HGI group.
CONCLUSIONS. Between-individual biological variation
in HbA1c, which is distinct from that attributable
to MBG, was evident among type 1 diabetic patients
in the DCCT and was a strong predictor of risk
for diabetes complications. Identification of the processes
responsible for biological variation in HbA1c
could lead to novel therapies to augment treatments
directed at lowering blood glucose levels and preventing
diabetes complications
Observation of the decay Bs0→D¯0K+K−
The first observation of the B0 s → D¯ 0KþK− decay is reported, together with the most precise branching fraction measurement of the mode B0 → D¯ 0KþK−. The results are obtained from an analysis of pp collision data corresponding to an integrated luminosity of 3.0 fb−1. The data were collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. The branching fraction of the B0 → D¯ 0KþK− decay is measured relative to that of the decay B0 → D¯ 0πþπ− to be BðB0→D¯ 0KþK−Þ BðB0→D¯ 0πþπ−Þ ¼ ð6.9 0.4 0.3Þ%, where the first uncertainty is statistical and the second is systematic. The measured branching fraction of the B0 s → D¯ 0KþK− decay mode relative to that of the corresponding B0 decay is BðB0 s→D¯ 0KþK−Þ BðB0→D¯ 0KþK−Þ ¼ ð93.0 8.9 6.9Þ%. Using the known branching fraction of B0 → D¯ 0πþπ−, the values of BðB0 →D¯ 0KþK−Þ¼ð6.10.40.30.3Þ×10−5 and BðB0 s →D¯ 0KþK−Þ¼ð5.70.50.40.5Þ×10−5 are obtained, where the third uncertainties arise from the branching fraction of the decay modes B0 → D¯ 0πþπ− and B0 → D¯ 0KþK−, respectively
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