Differential monocular vs. binocular pupil responses from melanopsin-based photoreception in patients with anterior ischemic optic neuropathy.

We examined the effect of anterior ischemic optic neuropathy (AION) on the activity of intrinsically photosensitive retinal ganglion cells (ipRGCs) using the pupil as proxy. Eighteen patients with AION (10 unilateral, 8 bilateral) and 29 age-matched control subjects underwent chromatic pupillometry. Red and blue light stimuli increasing in 0.5 log steps were presented to each eye independently under conditions of dark and light adaptation. The recorded pupil contraction was plotted against stimulus intensity to generate scotopic and photopic response curves for assessment of synaptically-mediated ipRGC activity. Bright blue light stimuli presented monocularly and binocularly were used for melanopsin activation. The post-stimulus pupil size (PSPS) at the 6th second following stimulus offset was the marker of intrinsic ipRGC activity. Finally, questionnaires were administered to assess the influence of ipRGCs on sleep. The pupil response and PSPS to all monocularly-presented light stimuli were impaired in AION eyes, indicating ipRGC dysfunction. To binocular light stimulation, the PSPS of AION patients was similar to that of controls. There was no difference in the sleep habits of the two groups. Thus after ischemic injury to one or both optic nerves, the summated intrinsic ipRGC activity is preserved when both eyes receive adequate light exposure

Visualization Tools for Clustering, Trees and Ordered Trees

Consider the situation of a set of individuals visiting a library and browsing through a collection. Each individual will, of course, select different books to browse depending on the original purpose of the visit. In addition, the order in which they search through a catalog will differ. The order is often ignored, yet might provide interesting cues as to the importance of certain books or topics. This scenario is not limited to browsing physical collections, but rather is repeated almost continually in other information-seeking behaviors including searching of on-line databases and hypenext/hypermedia systems

Nonlinear Dynamic System Identification in the Spectral Domain Using Particle-Bernstein Polynomials

System identification (SI) is the discipline of inferring mathematical models from unknown dynamic systems using the input/output observations of such systems with or without prior knowledge of some of the system parameters. Many valid algorithms are available in the literature, including Volterra series expansion, Hammerstein–Wiener models, nonlinear auto-regressive moving average model with exogenous inputs (NARMAX) and its derivatives (NARX, NARMA). Different nonlinear estimators can be used for those algorithms, such as polynomials, neural networks or wavelet networks. This paper uses a different approach, named particle-Bernstein polynomials, as an estimator for SI. Moreover, unlike the mentioned algorithms, this approach does not operate in the time domain but rather in the spectral components of the signals through the use of the discrete Karhunen–Loève transform (DKLT). Some experiments are performed to validate this approach using a publicly available dataset based on ground vibration tests recorded from a real F-16 aircraft. The experiments show better results when compared with some of the traditional algorithms, especially for large, heterogeneous datasets such as the one used. In particular, the absolute error obtained with the prosed method is 63% smaller with respect to NARX and from 42% to 62% smaller with respect to various artificial neural network-based approaches

Quantification of the early pupillary dilation kinetic to assess rod and cone activity.

Rods, cones and melanopsin contribute in various proportions, depending on the stimulus light, to the pupil light response. This study used a first derivative analysis to focus on the quantification of the dynamics of pupillary dilation that immediately follows light-induced pupilloconstriction in order to identify novel parameters that reflect rod and cone activity. In 18 healthy adults, the pupil response to a 1 s blue light stimulus ranging from - 6.0 to 2.65 log cd/m <sup>2</sup> in dark-adapted conditions and to a 1 s blue light stimulus (2.65 log cd/m <sup>2</sup> ) in light-adapted conditions was recorded on a customized pupillometer. Three derivative parameters which describe the 2.75 s following the light onset were quantified: dAMP (maximal amplitude of the positive peak), dLAT (latency of the positive peak), dAUC (area under the curve of the positive peak). We found that dAMP and dAUC but not dLAT have graded responses over a range of light intensities. The maximal positive value of dAMP, representing maximal rate of change of early pupillary dilation phase, occurs at - 1.0 log cd/m <sup>2</sup> and this stimulus intensity appears useful for activating rods and cones. From - 0.5 log cd/m <sup>2</sup> to brighter intensities dAMP and dAUC progressively decrease, reaching negligible values at 2.65 log cd/m <sup>2</sup> indicative of a melanopsin-driven pupil response that masks the contribution from rods and cones to the early phase of pupillary dilation

Therapeutical use of the cannabinoids in psychiatry

OBJETIVO: Revisar os principais avanços no potencial uso terapêutico de alguns compostos canabinoides em psiquiatria. MÉTODO: Foi realizada busca nos bancos de dado PubMed, SciELO e Lilacs e identificados estudos e revisões da literatura sobre o uso terapêutico dos canabinoides em psiquiatria, em particular canabidiol, rimonabanto, Δ9-tetraidrocanabinol e seus análogos. RESULTADOS: O canabidiol demonstrou apresentar potencial terapêutico como antipsicótico, ansiolítico, antidepressivo e em diversas outras condições. O Δ9-tetraidrocanabinol e seus análogos demonstraram efeitos ansiolíticos, na dependência de cannabis, bem como adjuvantes no tratamento de esquizofrenia, apesar de ainda carecerem de mais estudos. O rimonabanto demonstrou eficácia no tratamento de sintomas subjetivos e fisiológicos da intoxicação pela cannabis e como adjuvante no tratamento do tabagismo. Os potenciais efeitos colaterais, de induzir depressão e ansiedade limitaram o uso clínico deste antagonista CB1. CONCLUSÃO: Os canabinoides têm demonstrado que podem ter amplo interesse terapêutico em psiquiatria, porém mais estudos controlados são necessários para confirmar estes achados e determinar a segurança destes compostos.OBJECTIVE: To review the main advances related to the potential therapeutic use of cannabinoid compounds in psychiatry. METHOD: A search was performed in the online databases PubMed, ScieELO, and Lilacs for studies and literature reviews concerning therapeutic applications of cannabinoids in psychiatry, especially cannabidiol, rimonabant, Δ9-tetrahydrocannabinol, and their analogues. RESULTS: Cannabidiol was found to have therapeutic potential with antipsychotic, anxiolytic, and antidepressant properties, in addition to being effective in other conditions. Δ9-tetrahydrocannabinol and its analogues were shown to have anxiolytic effects in the treatment of cannabis dependence and to function as an adjuvant in the treatment of schizophrenia, although additional studies are necessary to support this finding. Rimonabant was effective in the treatment of the subjective and physiological symptoms of cannabis intoxication and functioned as an adjuvant in the treatment of tobacco addiction. The potential to induce adverse reactions such as depression and anxiety restrained the clinical use of this CB1 antagonist. CONCLUSION: Cannabinoids may be of great therapeutic interest to psychiatry; however, further controlled trials are necessary to confirm the existing findings and to establish the safety of such compounds

Investigation on the microbiological hazards in an artisanal soft cheese produced in northern Italy and its production environment in different seasonal periods

The present study aimed at assessing the occurrence of microbiological hazards (Listeria monocytogenes, Staphylococcus aureus, Salmonella spp. and Escherichia coli O157) in an artisanal soft cheese produced in northern Italy. In the same product total bacterial count, lactic acid bacteria and Enterobacteriaceae were enumerated, and pH and water activity measured in two batches sampled in summer and winter. Samples of raw materials, environmental swabs from the production processes and cheese during 15 days of storage at 2 and 8°C as well as dynamic temperature of 2°C for 5 days and 8°C for 10 days were collected and tested. The load of total bacterial count was significantly higher in the winter batch in comparison to the summer one, with a significant increase at the end of the storage period also noticed for lactic acid bacteria. Statistical higher values of pH were registered in raw materials and end of storage in winter batch. S. aureus was con-firmed only in the winter batch within samples (n=4) of stored cheese. On plates used for E. coli O157 detection, colonies of Klebsiella pneumoniae and Klebsiella oxy-toca were isolated. The results suggest that the highest bacterial population in the winter batch was associated to a higher pH in stored cheese and a higher number of bio-logical hazards identified. Their isolation started in the maturation room suggesting this step as relevant for possible cheese contamination

Determination of Rod and Cone Influence to the Early and Late Dynamic of the Pupillary Light Response.

PURPOSE: This study aims to identify which aspects of the pupil light reflex are most influenced by rods and cones independently by analyzing pupil recordings from different mouse models of photoreceptor deficiency. METHODS: One-month-old wild type (WT), rodless (Rho-/-), coneless (Cnga3-/-), or photoreceptor less (Cnga3-/-; Rho-/- or Gnat1-/-) mice were subjected to brief red and blue light stimuli of increasing intensity. To describe the initial dynamic response to light, the maximal pupillary constriction amplitudes and the derivative curve of the first 3 seconds were determined. To estimate the postillumination phase, the constriction amplitude at 9.5 seconds after light termination was related to the maximal constriction amplitude. RESULTS: Rho-/- mice showed decreased constriction amplitude but more prolonged pupilloconstriction to all blue and red light stimuli compared to wild type mice. Cnga3-/- mice had constriction amplitudes similar to WT however following maximal constriction, the early and rapid dilation to low intensity blue light was decreased. To high intensity blue light, the Cnga3-/- mice demonstrated marked prolongation of the pupillary constriction. Cnga3-/-; Rho-/- mice had no pupil response to red light of low and medium intensity. CONCLUSIONS: From specific gene defective mouse models which selectively voided the rod or cone function, we determined that mouse rod photoreceptors are highly contributing to the pupil response to blue light stimuli but also to low and medium red stimuli. We also observed that cone cells mainly drive the partial rapid dilation of the initial response to low blue light stimuli. Thus photoreceptor dysfunction can be derived from chromatic pupillometry in mouse models

Molecular communications in complex systems of dynamic supramolecular polymers

Supramolecular polymers are composed of monomers that self-assemble non-covalently, generating distributions of monodimensional fibres in continuous communication with each other and with the surrounding solution. Fibres, exchanging molecular species, and external environment constitute a sole complex system, which intrinsic dynamics is hard to elucidate. Here we report coarse-grained molecular simulations that allow studying supramolecular polymers at the thermodynamic equilibrium, explicitly showing the complex nature of these systems, which are composed of exquisitely dynamic molecular entities. Detailed studies of molecular exchange provide insights into key factors controlling how assemblies communicate with each other, defining the equilibrium dynamics of the system. Using minimalistic and finer chemically relevant molecular models, we observe that a rich concerted complexity is intrinsic in such self-assembling systems. This offers a new dynamic and probabilistic (rather than structural) picture of supramolecular polymer systems, where the travelling molecular species continuously shape the assemblies that statistically emerge at the equilibrium