15 research outputs found
The Evolution of Primate Short-Term Memory.
Short-term memory is implicated in a range of cognitive abilities and is critical for understanding primate
cognitive evolution. To investigate the effects of phylogeny, ecology and sociality on short-term memory, we tested the largest and most diverse primate sample to date (421 non-human primates across 41 species) in an experimental delayed-response task. Our results confirm previous findings that longer delays decrease memory performance across species and taxa. Our analyses demonstrate a considerable contribution of phylogeny over ecological and social factors on the distribution of short-term memory performance in primates; closely related species had more similar short-term memory abilities. Overall, individuals in the branch of Hominoidea performed better compared to Cercopithecoidea, who in turn performed above Platyrrhini and Strepsirrhini. Interdependencies between phylogeny and socioecology of a given species presented an obstacle to disentangling the effects of each of these factors on the evolution of short-term memory capacity. However, this study offers an important step forward in understanding the interspecies and individual variation in short-term memory ability by providing the first phylogenetic reconstruction of this trait’s evolutionary history. The dataset constitutes a unique resource for studying the evolution of primate cognition and the role of short-term memory in other cognitive abilities.info:eu-repo/semantics/publishedVersio
The Evolution of Primate Short-Term Memory
Short-term memory is implicated in a range of cognitive abilities and is critical for understanding primate cognitive evolution. To investigate the effects of phylogeny, ecology and sociality on short-term memory, we tested the largest and most diverse primate sample to date (421 non-human primates across 41 species) in an experimental delayed-response task. Our results confirm previous findings that longer delays decrease memory performance across species and taxa. Our analyses demonstrate a considerable contribution of phylogeny over ecological and social factors on the distribution of short-term memory performance in primates; closely related species had more similar short-term memory abilities. Overall, individuals in the branch of Hominoidea performed better compared to Cercopithecoidea, who in turn performed above Platyrrhini and Strepsirrhini. Interdependencies between phylogeny and socioecology of a given species presented an obstacle to disentangling the effects of each of these factors on the evolution of short-term memory capacity. However, this study offers an important step forward in understanding the interspecies and individual variation in short-term memory ability by providing the first phylogenetic reconstruction of this trait’s evolutionary history. The dataset constitutes a unique resource for studying the evolution of primate cognition and the role of short-term memory in other cognitive abilities
Levels of retinol and retinoic acid in pancreatic cancer, type-2 diabetes and chronic pancreatitis
Aims. Retinoids participate in multiple key processes in the human body e.g., vision, cell differentiation and embryonic development. There is growing evidence of the relationship between retinol, its active metabolite- all-trans retinoic acid (ATRA) - and several pancreatic disorders. Although low levels of ATRA in pancreatic ductal adenocarcinoma (PDAC) tissue have been reported, data on serum levels of ATRA in PDAC is still limited. The aim of our work was to determine serum concentrations of retinol and ATRA in patients with PDAC, type-2 diabetes mellitus (T2DM), chronic pancreatitis (CHP) and healthy controls. Methods. High performance liquid chromatography with UV detection (HPLC) was used to measure serum levels of retinol and ATRA in 246 patients with different stages of PDAC, T2DM, CHP and healthy controls. Results. We found a significant decrease in the retinol concentration in PDAC (0.44+/-0.18 mg/L) compared to T2DM (0.65+/-0.19 mg/L, P<0.001), CHP (0.60+/-0.18 mg/L, P< 0.001) and healthy controls (0.61+/-0.15 mg/L, P<0.001), significant decrease of ATRA levels in PDAC (1.14+/-0.49 ug/L) compared to T2DM (1.37+/-0.56 ug/L, P<0.001) and healthy controls(1.43+/-0.55 ug/L, P<0.001). Differences between early stages (I+II) of PDAC and non-carcinoma groups were not significant. We describe correlations between retinol, prealbumin and transferrin, and correlation of ATRA and IGFBP-2. Conclusion. Significant decrease in retinol and ATRA levels in PDAC compared to T2DM, healthy individuals and/or CHP supports existing evidence of the role of retinoids in PDAC. However, neither ATRA nor retinol are suitable for detection of early PDAC. Correlation of ATRA levels and IGFBP-2 provides new information about a possible IGF and retinol relationship
Ceramic phononic crystals with MHz-range frequency band gaps
Robocasting is an additive manufacturing method, which is capable of fabricating microarchitectured
scaffolds, consisting of periodically repeating thin ceramic rods in various spatial arrangements. Fully
sintered ceramic scaffolds are obtained by a combination of layer-by-layer 3D printing and subsequent
presureless spark plasma sintering of the printed green ceramic bodies. Due to the complex structures with
easily tunable geometric parameters, phononic crystals can be fabricated by the robocasting method. In this
contribution, elastic and acoustic properties of the robocast silicon carbide scaffold are shown, utilizing a
combination of resonant ultrasound spectroscopy measurement and finite element modeling. The scaffold is
highly anisotropic in elastic properties, which leads to a strong acoustic energy focusing along the principal
axes of the silicon carbide rods. Moreover, frequency band gaps in MHz range are detected by measur-ing
longitudinal wave transmission, which is compared with a theoretical prediction by the finite element
modeling.This work was supported by the Czech Science Foundation grant No. 17-01618S, and Spanish Project MAT2015-67437-R (MINECO, FEDER, UE).Peer Reviewe
Improved stability second harmonic conversion of a diode-pumped Yb:YAG laser at the 0.5 kW level
We report on efficient and stable, type-I phase-matched second harmonic conversion of a nanosecond high-energy, diode-pumped, Yb:YAG laser. With a frequency-doubling crystal in an enclosed, temperature controller with optical windows, 0.5% energy stability was achieved for approximately half an hour. This resulted in 48.9 J pulses at 10 Hz (489 W) and a conversion efficiency of 73.8%. These results are particularly important for stable and reliable operation of high-energy, frequency-doubled lasers.</p
Improved stability second harmonic conversion of a diode-pumped Yb:YAG laser at the 0.5 kW level
We report on efficient and stable, type-I phase-matched second harmonic conversion of a nanosecond high-energy, diode-pumped, Yb:YAG laser. With a frequency-doubling crystal in an enclosed, temperature controller with optical windows, 0.5% energy stability was achieved for approximately half an hour. This resulted in 48.9 J pulses at 10 Hz (489 W) and a conversion efficiency of 73.8%. These results are particularly important for stable and reliable operation of high-energy, frequency-doubled lasers.</p
The European Association of Urology (EAU) Guidelines Methodology: A Critical Evaluation
Objectives: Guidelines can be produced and written in numerous ways. The
aim of the present article is to describe and evaluate the method
currently used to produce the European Association of Urology (EAU)
guidelines.
Design, setting, and participants: The methodology is described in
detail, compared to other urologic guidelines by members of the EAU
Guidelines Office Board.
Measurements: The new methodology is evaluated by the Appraisal of
Guidelines for Research and Evaluation (AGREE) instrument.
Results and limitations: The currently used methodology is adapted to
the aims and objectives as established by the EAU for their guidelines;
wide coverage (essentially all fields of urology) and useful to
urologists all over Europe. The frequent updates are easily accessible
in a printed and electronic format. The AGREE instrument supports these
strong points, but also identifies potentially weak points, such as no
patient involvement, no formal validation of the guidelines texts prior
to publication, and lack of discussion of organisational barriers and
cost implications.
Conclusion: The currently used methodology for the production of EAU
guidelines fulfils the association’s main objectives related to their
guidelines, but the texts will benefit from the inclusion of
country-specific cost and organisational data. For the practising
clinician, these guidelines will help to take science into clinical
practice. (C) 2008 European Association of Urology. Published by
Elsevier B. V. All rights reserved