46 research outputs found
Clinical case: Mayer-Rokitansky-Kuster-Hauser syndrome, atypic form
Secţia Urologie IMSP SCM „Sf. Treime”, Catedra Urologie şi Nefrologie Chirurgicală, USMF „N. Testemiţanu”, Al V-lea Congres de Urologie, Dializă şi Transplant Renal din Republica Moldova cu participare internaţională (1-13 iunie 2011)Summary The Mayer-Rokitansky-kuster-Hauser (MRkH) syndrome is a rare anomaly in the prenatal development of the female genital tract. In this paper we report a clinical case of this syndrome observed in its atypical form with affected urogenital system, as well as uterine and renal agenesia. This case is interesting, as the patient did not receive any specific treatment associated with the syndrome until the age of 29. We provide a detailed description of the clinical case, its specifics and anamnesis. A literature review on the prenatal development of the female genital tract, urogenital system and the renal agenesia is also given
Prolonged light exposure induces widespread phase shifting in the circadian clock and visual pigment gene expression of the Arvicanthis ansorgei retina.
PURPOSE: Prolonged periods of constant lighting are known to perturb circadian clock function at the molecular, physiological, and behavioral levels. However, the effects of ambient lighting regimes on clock gene expression and clock outputs in retinal photoreceptors--rods, cones and intrinsically photosensitive retinal ganglion cells--are only poorly understood.
METHODS: Cone-rich diurnal rodents (Muridae: Arvicanthis ansorgei) were maintained under and entrained to a 12 h:12 h light-dark cycle (LD; light: ~300 lux). Three groups were then examined: control (continued maintenance on LD); animals exposed to a 36 h dark period before sampling over an additional 24 h period of darkness (DD); and animals exposed to a 36 h light period before sampling over an additional 24 h period of light (~300 lux, LL). Animals were killed every 3 or 4 h over 24 h, their retinas dissected, and RNA extracted. Oligonucleotide primers were designed for the Arvicanthis clock genes Per1, Per2, Cry1, Cry2, and Bmal1, and for transcripts specific for rods (rhodopsin), cones (short- and mid-wavelength sensitive cone opsin, cone arrestin, arylalkylamine N-acetyltransferase) and intrinsically photosensitive retinal ganglion cells (melanopsin). Gene expression was analyzed by real-time PCR.
RESULTS: In LD, expression of all genes except cone arrestin was rhythmic and coordinated, with acrophases of most genes at or shortly following the time of lights on (defined as zeitgeber time 0). Arylalkylamine N-acetyltransferase showed maximal expression at zeitgeber time 20. In DD conditions the respective profiles showed similar phase profiles, but were mostly attenuated in amplitude, or in the case of melanopsin, did not retain rhythmic expression. In LL, however, the expression profiles of all clock genes and most putative output genes were greatly altered, with either abolition of daily variation (mid-wavelength cone opsin) or peak expression shifted by 4-10 h.
CONCLUSIONS: These data are the first to provide detailed measures of retinal clock gene and putative clock output gene expression in a diurnal mammal, and show the highly disruptive effects of inappropriate (nocturnal) lighting on circadian and photoreceptor gene regulationjournal articleresearch support, non-u.s. gov't20132013 05 21importe
The estimation of the peculiarities and the activity degree of the consisting inflammatory processes in the benign prostatic hyperplasia
Secţia Urologie, IMSP Spitalul Clinic Municipal “ Sf. Treime”, Catedra Morfopatologie, USMF „N. Testemiţanu”, Secţia Ştiinţifică Morfopatologie, IMSP Institutul de Cercetări Ştiinţifice în Domeniul Ocrotirii Sănătăţii Mamei şi Copilului, Catedra Urologie şi Nefrologie Chirurgicală, USMF „N. Testemiţanu”, Al V-lea Congres de Urologie, Dializă şi Transplant Renal din Republica Moldova cu participare internaţională (1-13 iunie 2011)Summary. The conducted study has the aim to estimate the histopathological peculiarities of the inflammatory processes, evaluated in prostatic nodular hyperplasia, the character and the activity of these processes in the area of nodular hyperplasia structures, and the border limit in the adenectomy. The results of the morphopathological study allowed detailed diagnosis of the prostatic hyperplasia. Severe modifications of inflammatory origin and considerable implications of the structural-architectonical components indicate concomitant persisting or coexisting of chronic or acute prostatitis. The establishment of the lesion character, activity degree of the inflammatory process, saving border limit in the surgical management regarding the residual cavity of cleavage and postoperative prognosis was the second aim of the study. It facilitates the choice of the best therapeutic and surgical approach. The character of the inflammatory processes coexisting with prostatic benign hyperplasia was evaluated. A clinical-morphological concept of inflammatory associations in prostate benign hyperplasia was formulated
Getting aligned on representational alignment
Biological and artificial information processing systems form representations
that they can use to categorize, reason, plan, navigate, and make decisions.
How can we measure the extent to which the representations formed by these
diverse systems agree? Do similarities in representations then translate into
similar behavior? How can a system's representations be modified to better
match those of another system? These questions pertaining to the study of
representational alignment are at the heart of some of the most active research
areas in cognitive science, neuroscience, and machine learning. For example,
cognitive scientists measure the representational alignment of multiple
individuals to identify shared cognitive priors, neuroscientists align fMRI
responses from multiple individuals into a shared representational space for
group-level analyses, and ML researchers distill knowledge from teacher models
into student models by increasing their alignment. Unfortunately, there is
limited knowledge transfer between research communities interested in
representational alignment, so progress in one field often ends up being
rediscovered independently in another. Thus, greater cross-field communication
would be advantageous. To improve communication between these fields, we
propose a unifying framework that can serve as a common language between
researchers studying representational alignment. We survey the literature from
all three fields and demonstrate how prior work fits into this framework.
Finally, we lay out open problems in representational alignment where progress
can benefit all three of these fields. We hope that our work can catalyze
cross-disciplinary collaboration and accelerate progress for all communities
studying and developing information processing systems. We note that this is a
working paper and encourage readers to reach out with their suggestions for
future revisions.Comment: Working paper, changes to be made in upcoming revision
Novel Rodent Models for Macular Research
BACKGROUND: Many disabling human retinal disorders involve the central retina, particularly the macula. However, the commonly used rodent models in research, mouse and rat, do not possess a macula. The purpose of this study was to identify small laboratory rodents with a significant central region as potential new models for macular research.
METHODOLOGY/PRINCIPAL FINDINGS: Gerbillus perpallidus, Meriones unguiculatus and Phodopus campbelli, laboratory rodents less commonly used in retinal research, were subjected to confocal scanning laser ophthalmoscopy (cSLO), fluorescein and indocyanine green angiography, and spectral-domain optical coherence tomography (SD-OCT) using standard equipment (Heidelberg Engineering HRA1 and Spectralis™) adapted to small rodent eyes. The existence of a visual streak-like pattern was assessed on the basis of vascular topography, retinal thickness, and the topography of retinal ganglion cells and cone photoreceptors. All three species examined showed evidence of a significant horizontal streak-like specialization. cSLO angiography and retinal wholemounts revealed that superficial retinal blood vessels typically ramify and narrow into a sparse capillary net at the border of the respective area located dorsal to the optic nerve. Similar to the macular region, there was an absence of larger blood vessels in the streak region. Furthermore, the thickness of the photoreceptor layer and the population density of neurons in the ganglion cell layer were markedly increased in the visual streak region.
CONCLUSIONS/SIGNIFICANCE: The retinal specializations of Gerbillus perpallidus, Meriones unguiculatus and Phodopus campbelli resemble features of the primate macula. Hence, the rodents reported here may serve to study aspects of macular development and diseases like age-related macular degeneration and diabetic macular edema, and the preclinical assessment of therapeutic strategies
Review of the techniques used in motor‐cognitive human‐robot skill transfer
Abstract A conventional robot programming method extensively limits the reusability of skills in the developmental aspect. Engineers programme a robot in a targeted manner for the realisation of predefined skills. The low reusability of general‐purpose robot skills is mainly reflected in inability in novel and complex scenarios. Skill transfer aims to transfer human skills to general‐purpose manipulators or mobile robots to replicate human‐like behaviours. Skill transfer methods that are commonly used at present, such as learning from demonstrated (LfD) or imitation learning, endow the robot with the expert's low‐level motor and high‐level decision‐making ability, so that skills can be reproduced and generalised according to perceived context. The improvement of robot cognition usually relates to an improvement in the autonomous high‐level decision‐making ability. Based on the idea of establishing a generic or specialised robot skill library, robots are expected to autonomously reason about the needs for using skills and plan compound movements according to sensory input. In recent years, in this area, many successful studies have demonstrated their effectiveness. Herein, a detailed review is provided on the transferring techniques of skills, applications, advancements, and limitations, especially in the LfD. Future research directions are also suggested
Ozone photolysis of paracetamol in aqueous solution.
The degradation of a paracetamol (N-acetil-para-aminofenol) aqueous solution (C-0 (P) = 5mmol L-1) is studied in a bench-scale setup by means of simple ozonation (O-3) and ozonation catalyzed with UV light (O-3/UV) in order to quantify the influence of UV light on the degradation process. The results have shown that under the adopted experimental conditions (25 degrees C, applied ozone dose = 9.8mg L-1 and gas flow rate of 20 L h(1)) both oxidative systems are capable of removing the substrate with mineralization degrees up to 51% for ozonation and 53% for O-3/UV. HPICE chromatography allowed the detection of nitrate ions and maleic and oxalic acids as ultimate carboxylic acids. The experimental data have been interpreted through 5 indicators: the conversion of paracetamol (X-P ), the conversion degree of TOC (X-TOC ), the apparent rate constant (k(ap) ), the Hatta number (Ha) and the enhancement factor (E). The main advantage of photo-ozonation compared to simple ozonation was a more advanced conversion (79% vs. 92% after 90min). The paracetamol decay follows a pseudofirst-order reaction with a superior rate constant (higher by 54%) for the UV catalyzed system in comparison with direct ozonation. Mineralization is slightly accelerated (+4%) in the O-3/UV system, due to the additional production of hydroxyl radicals induced by the UV light and a higher Hatta number (+24%). Nevertheless, the process was still in the slow reaction kinetic regime (Ha < 0.3), and the enhancement factor was not significantly increased. The results are useful for the design and scale-up of the gas-liquid processes
Degradation studies of ciprofloxacin on a pillared iron catalyst.
Photo-assisted Fenton mineralization of ciprofloxacin (CFX), a broad-spectrum antibiotic used in human and veterinary medicine was studied using a modified laponite clay-based Fe nanocomposite (Fe-Lap-RD) as a heterogeneous catalyst in the presence of hydrogen peroxide and UV light. The catalytic performance has been monitored in terms of CFX (0.15 mM) and total organic carbon (TOC) conversions, whereas the catalyst stability was evaluated according to the metal leached from the solid structure into the aqueous solution. The Fe-Lap-RD was characterized by X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) techniques. Further, the effects of reaction parameters such as H2O2 concentration, Fe-Lap-RD catalyst loading and initial solution pH on the mineralization of CFX were investigated. It was found that at the optimal reaction conditions (60 mM H2O2, 1.0 g L-1 Fe-Lap-RD, initial solution pH 3.0), complete CFX degradation and over 57% total organic carbon (TOC) removal of CFX can be achieved after 30 min reaction. In addition degradation and mineralization kinetics of CFX was also studied to obtain apparent reaction rate constants. The photo-Fenton degradation of CFX follows the pseudo-first-order kinetics. Fe-Lap-RD exhibits good catalytic activity in the photodegradation and mineralization of CFX, with negligible leaching of Fe ions from the catalyst structure
Synthesis and characterization of n-alkyl chitosan for papermaking applications
cited By 9International audienceChitosan is a natural cationic polymer whose reactive amino groups and primary and secondary hydroxyl groups confer to it interesting properties for papermaking applications, such as cationic polyelectrolyte behavior and high affinity for the cellulose fiber surface. However, the main barrier to these applications of chitosan is the lack of water solubility under neutral pH of the wet-end papermaking system. This paper is aimed at obtaining and characterizing a water-soluble chitosan derivative by introducing alkyl groups along the chitosan chain, to confer to it hydrophobic nature, without affecting significantly its cationic character. The N-alkyl chitosan derivative was obtained by reductive amination, and was investigated by spectroscopic techniques (FT-IR, 1H-NMR, and MS), solubility in water and ionic charge density. The analysis demonstrated the obtaining of alkylated chitosan with a 0.03 substitution degree, completely soluble in water at room temperature, and with a cationic character in a neutral pH medium. These characteristics of N-alkyl chitosan, beside its amphiphilic nature induced by hydrophobic/hydrophilic sequences, make this polymer a very promising additive for papermaking applications