973 research outputs found
La geometría de visualización afecta el dicromatismo sexual y la conspicuidad de la coloración del plumaje no iridiscente de Tersina viridis
Some types of plumage color are difficult to characterize spectrophotometrically because the properties of the reflected light change with viewing geometry (i.e. the relative positions of the light source and the observer, and the orientation of the feather). This is the case for the noniridescent plumage coloration of the Swallow Tanager (Tersina viridis), which seems to change from a human perspective as the angle between the light source and the observer varies. In this study, we measured plumage reflectance with different angles of illumination and/or observation, and used avian visual models to evaluate the change in sexual dichromatism and conspicuousness with viewing geometry from a bird’s perspective. We also calculated different color parameters to assess how these changed with viewing conditions. Sexual dichromatism showed large changes, with its maximum coinciding with the angle combination between illuminant and observer that produced both the highest conspicuousness for males and the highest crypsis for females. The conspicuousness of males also varied with viewing geometry, and was consistently less when viewed by the visual system of a potential avian predator (VS) than by that of a conspecific (UVS). The change in perceived coloration was mainly related to large variation in hue and chroma in the plumage of males as the relative angle between the illumination and observation probes changed. Our results show that viewing geometry can alter color perception, even for noniridescent plumage coloration. Therefore, the relative position of the light source and the observer should be considered in studies of avian visual communication, particularly for species with plumage coloration similar to that of Swallow Tanagers.Algunos tipos de colores del plumaje son difíciles de caracterizar espectrofotometricamente debido a que las propiedades de la luz que reflejada varían con la geometría de visualización (es decir, la posición relativa de la fuente lumínica, el observador y la pluma). Este es el caso de la coloración no-iridiscente de la Tersina viridis, que parece cambiar desde la perspectiva humana al modificarse el ángulo conformado entre el observador y la fuente de luz. En este trabajo medimos la reflectancia del plumaje con diferentes ángulos de iluminación y/o observación y empleamos modelos visuales avianos para evaluar el cambio en dicromatismo sexual y conspicuidad. Tambien calculamos parámetros descriptores de la coloración para determinar cómo cambian estos en función de la geometría de visualización. El dicromatismo sexual mostró una amplia variación, siendo máximo con la combinación de ángulos entre iluminante y observador que también produjo el máximo de conspicuidad en los machos y el máximo de cripsis en las hembras. La conspicuidad de los machos tambien varió con la geometría de visualización y además fue consistentemente menor para sistemas visuales avianos menos sensibles al UV (como los de los máximos potenciales predadores de esta especie) que para sus conspecíficos, que serían más sensibles a longitudes de onda del UV. El cambio percibido en la coloración estuvo principalmente relacionado a una gran variación en el tono y la saturación en el plumaje de los machos al cambiar el ángulo conformado entre la fuente lumínica y el observador. Nuestros resultados muestran que la geometría de visualización puede alterar la percepción del color, a un en plumajes no-iridiscentes. Por lo tanto, es importante considerar la posición relativa de la fuente de luz y el observador en estudios de comunicación visual en aves, particularmente en especies con coloración del plumaje como la de la Tersina viridis.Fil: Barreira, Ana Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: García, Natalia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Lougheed, Stephen C.. Queens University, Department Of Biology; CanadáFil: Tubaro, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin
HOW TO OVERCOME ANALPHABETISM IN READING CHINESE CHARACTER
Most languages in the world use some system of alphabetical characters: Latin, Greek, Cyrillic, Hebrew, Arabic, Hindi and so on. A foreigner that does not know the language can get some information from a written text provided he knows the alphabet and disposes of a dictionary. When there is no longer an alphabet, but only pictorial characters, the problem becomes at first unsolvable. Chinese is the main language where an ignorant foreigner is completely analphabet. Fortunately there are methods that after some training allow the recognition of pictorial characters. In our university some twenty pupils of the Excellence School participated to an experiment of Chinese alphabetization gluing a traditional practical Chinese first course with information theory methods for dealing with image data bases. In this article first we discuss both the theoretical foundations. Then we give a report of the merging of the two conceptual schemes as it was performed at the excellence school. Finally we draw some conclusions about improvements of the method
Is there a link between overactive bladder and the metabolic syndrome in women? : A systematic review of observational studies
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.To conduct a systematic review to determine whether there is an association between metabolic syndrome (MetS) and lower urinary tract symptoms (LUTS) or overactive bladder (OAB) in women. We systematically reviewed English language observational studies on the effect of MetS (or component factors) on the presence of OAB or LUTS in women. We searched PubMed, Web of Science and The Cochrane Library with no date restrictions, checked reference lists and undertook citation searches in PubMed and Google Scholar. Studies were assessed for risk of bias. Because of heterogeneity, results were not pooled, but are reported narrativelyPeer reviewe
Complex renal masses: Partial or no partial nephrectomy?
Management of high complexity renal masses is always challenging for urologists. Beksac and co-workers made a great effort in collecting data from 144 patients with complex renal masses defined as a RENAL score higher than 10 undergoing robotic partial nephrectomy (RPN). Trifecta was achieved in 62% of the patients. The multi-center design of the study is an important feature considering that 6 surgeons were involved. The study is retrospective and follow up is short therefore data should be managed with caution. Their study confirms the available evidence on the subject, confirming that in expert hands RPN should be performed whenever deemed feasible
Functional and Structural Biological Methods for Palytoxin Detection
Palytoxin (PLTX) and its analogues are marine polyethers identified in Palythoa and Zoanthus
corals, Ostreopsis dinoflagellates, and Trichodesmium cyanobacteria. Humans can be exposed
to these toxins by different routes with a series of adverse effects but the most severe risk is associated with poisonings by the consumption of edible marine organisms accumulating these toxins, as occurs in (sub)-tropical areas. In temperate areas, adverse effects ascribed to PLTXs have been recorded after inhalation of marine aerosols and/or cutaneous contact with seawater during Ostreopsis blooms, as well as during cleaning procedures of Palythoa-containing home aquaria. Besides instrumental analytical methods, in the last years a series of alternative or complementary methods based on biological/biochemical tools have been developed for the rapid and specific PLTX detection required for risk assessment. These methods are usually sensitive, cost- and time-effective, and do not require highly specialized operators. Among them, structural immunoassays and functional cellbased assays are reviewed. The availability of specific anti-PLTX antibodies allowed the development of different sensitive structural assays, suitable for its detection also in complex matrices, such as mussels. In addition, knowing the mechanism of PLTX action, a series of functional identification methods has been developed. Despite some of them being limited by matrix effects and specificity issues, biological methods for PLTX detection represent a feasible tool, suitable for rapid screening
TIMIT-TTS: a Text-to-Speech Dataset for Multimodal Synthetic Media Detection
With the rapid development of deep learning techniques, the generation and
counterfeiting of multimedia material are becoming increasingly straightforward
to perform. At the same time, sharing fake content on the web has become so
simple that malicious users can create unpleasant situations with minimal
effort. Also, forged media are getting more and more complex, with manipulated
videos that are taking the scene over still images. The multimedia forensic
community has addressed the possible threats that this situation could imply by
developing detectors that verify the authenticity of multimedia objects.
However, the vast majority of these tools only analyze one modality at a time.
This was not a problem as long as still images were considered the most widely
edited media, but now, since manipulated videos are becoming customary,
performing monomodal analyses could be reductive. Nonetheless, there is a lack
in the literature regarding multimodal detectors, mainly due to the scarsity of
datasets containing forged multimodal data to train and test the designed
algorithms. In this paper we focus on the generation of an audio-visual
deepfake dataset. First, we present a general pipeline for synthesizing speech
deepfake content from a given real or fake video, facilitating the creation of
counterfeit multimodal material. The proposed method uses Text-to-Speech (TTS)
and Dynamic Time Warping techniques to achieve realistic speech tracks. Then,
we use the pipeline to generate and release TIMIT-TTS, a synthetic speech
dataset containing the most cutting-edge methods in the TTS field. This can be
used as a standalone audio dataset, or combined with other state-of-the-art
sets to perform multimodal research. Finally, we present numerous experiments
to benchmark the proposed dataset in both mono and multimodal conditions,
showing the need for multimodal forensic detectors and more suitable data
Role of d-mannose in the prevention of recurrent uncomplicated cystitis: State of the art and future perspectives
Background: Urinary tract infections (UTI) are highly frequent in women, with a significant impact on healthcare resources. Although antibiotics still represent the standard treatment to manage recurrent UTI (rUTI), D-mannose, an inert monosaccharide that is metabolized and excreted in urine and acts by inhibiting bacterial adhesion to the urothelium, represents a promising nonantibiotic prevention strategy. The aim of this narrative review is to critically analyze clinical studies reporting data concerning the efficacy and safety of D-mannose in the management of rUTIs. Methods: A nonsystematic literature search, using the Pubmed, EMBASE, Scopus, Web of science, Cochrane Central Register of Controlled Trials, and Cochrane Central Database of Systematic Reviews databases, was performed for relevant articles published between January 2010 and January 2021. The following Medical Subjects Heading were used: “female/woman”, “urinary tract infection”, and “D-mannose”. Only clinical studies, systematic reviews, and meta-analyses reporting efficacy or safety data on D-mannose versus placebo or other competitors were selected for the present review. Evidence was limited to human data. The selected studies were organized in two categories according to the presence or not of a competitor to D-mannose. Results: After exclusion of non-pertinent studies/articles, 13 studies were analyzed. In detail, six were randomized controlled trials (RCTs), one a randomized cross-over trial, five prospective cohort studies, and one a retrospective analysis. Seven studies compared D-mannose to placebo or others drugs/dietary supplements. Six studies evaluated the efficacy of D-mannose comparing follow-up data with the baseline. D-mannose is well tolerated, with few reported adverse events (diarrhea was reported in about 8% of patients receiving 2 g of D-mannose for at least 6 months). Most of the studies also showed D-mannose can play a role in the prevention or rUTI or urodynamics-associated UTI and can overlap antibiotic treatments in some cases. The possibility to combine D-mannose with polyphenols or Lactobacillus seems another important option for UTI prophylaxis. However, the quality of the collected studies was very low, generating, consequently, a weak grade of recommendations as suggested by international guidelines. Data on D-mannose dose, frequency, and duration of treatment are still lacking. Conclusion: Dmannose alone or in combination with several dietary supplements or Lactobacillus has a potential role in the non antimicrobial prophylaxis or recurrent UTI in women. Despite its frequent prescription in real-life practice, we believe that further well-designed studies are urgently needed to definitively support the role of D-mannose in the management of recurrent UTIs in women
Insights on the Anion Effect in N-heterocyclic Carbene Based Dinuclear Gold(I) Catalysts
Dinuclear bisNHC (bis(N-heterocyclic carbene)) gold(I) complexes 3 a and 4 a of general formula [Au2Br2(bisNHC)] were tested as catalysts in the cycloisomerization of N-(prop-2-yn-1-yl)benzamide and in the hydromethoxylation of 3-hexyne in the presence of silver(I) activators bearing different counteranions. The catalytic performance of mononuclear NHC complexes (1 a, 2 a) in the same reactions was also studied. The results highlighted the fundamental role of both NHC ligand and counterion in the catalytic cycles and activation process: dinuclear catalysts exhibit higher initial activity even under milder conditions but suffer in terms of stability with respect to mono NHCs. Furthermore, a new dinuclear bisNHC gold(I) complex 4 b of general formula [Au2(OTs)2(bisNHC)] (OTs=p-toluenesulfonate) was successfully synthesized and characterized by means of NMR and ESI-MS analyses
Toxic equivalency factors (TEFs) after acute oral exposure of azaspiracid 1,-2 and-3 in mice
Azaspiracids (AZAs) are marine algal toxins that can be accumulated by edible shellfish to cause a foodborne gastrointestinal poisoning in humans. In the European Union, only AZA1, -2 and -3 are currently regulated and their concentration in shellfish is determined through their toxic equivalency factors (TEFs) derived from the intraperitoneal lethal potency in mice. Nevertheless, considering the potential human exposure by oral route, AZAs TEFs should be calculated by comparative oral toxicity data. Thus, the acute oral toxicity of AZA1, -2 and -3 was investigated in female CD-1 mice treated with different doses (AZA1: 135-1100 mu g/kg; AZA2 and AZA3: 300-1100 mu g/kg) and sacrificed after 24 h or 14 days. TEFs derived from the median lethal doses (LD50) were 1.0, 0.7 and 0.5, respectively for AZA1, -2 and -3. In fact, after 24 h from gavage administration, LD(50)s were 443 mu g/kg (AZA1; 95% CL: 350-561 mu g/kg), 626 mu g/kg (AZA2; 95% CL: 430-911 mu g/kg) and 875 mu g/kg (AZA3; 95% CL: 757-1010 mu g/kg). Mice dead more than 5 h after the treatment or those sacrificed after 24 h (doses: = 175 mu g AZA1/kg, >= 500 mu g AZA2/kg and >= 600 mu g AZA3/kg) showed enlarged pale liver, while increased serum markers of liver alteration were recorded even at the lowest doses. Blood chemistry revealed significantly increased serum levels of K+ ions (>= 500 mg/kg), whereas light microscopy showed tissue changes in the gastrointestinal tract, liver and spleen. No lethality, macroscopic, tissue or haematological changes were recorded two weeks post exposure, indicating reversible toxic effects. LC-MS/MS analysis of the main organs showed a dose-dependency in gastrointestinal absorption of these toxins: at 24 h, the highest levels were detected in the stomach and, in descending order, in the intestinal content, liver, small intestine, kidneys, lungs, large intestine, heart as well as detectable traces in the brain. After 14 days, AZA1 and AZA2 were still detectable in almost all the organs and intestinal content
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