Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.415
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Photochem Photobiol Sci ; 23(6): 1087-1115, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38763938

RESUMO

The protection of Earth's stratospheric ozone (O3) is an ongoing process under the auspices of the universally ratified Montreal Protocol and its Amendments and adjustments. A critical part of this process is the assessment of the environmental issues related to changes in O3. The United Nations Environment Programme's Environmental Effects Assessment Panel provides annual scientific evaluations of some of the key issues arising in the recent collective knowledge base. This current update includes a comprehensive assessment of the incidence rates of skin cancer, cataract and other skin and eye diseases observed worldwide; the effects of UV radiation on tropospheric oxidants, and air and water quality; trends in breakdown products of fluorinated chemicals and recent information of their toxicity; and recent technological innovations of building materials for greater resistance to UV radiation. These issues span a wide range of topics, including both harmful and beneficial effects of exposure to UV radiation, and complex interactions with climate change. While the Montreal Protocol has succeeded in preventing large reductions in stratospheric O3, future changes may occur due to a number of natural and anthropogenic factors. Thus, frequent assessments of potential environmental impacts are essential to ensure that policies remain based on the best available scientific knowledge.


Assuntos
Ozônio Estratosférico , Raios Ultravioleta , Humanos , Ozônio Estratosférico/análise , Raios Ultravioleta/efeitos adversos , Ozônio/química , Mudança Climática
2.
BMC Plant Biol ; 23(1): 404, 2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37620815

RESUMO

BACKGROUND: The complex systemic responses of tree species to fight pathogen infection necessitate attention due to the potential for yield protection in forestry. RESULTS: In this paper, both the localized and systemic responses of model plants, such as Arabidopsis and tobacco, are reviewed. These responses were compared to information available that investigates similar responses in woody plant species and their key differences were highlighted. In addition, tree-specific responses that have been documented were summarised, with the critical responses still relying on certain systemic acquired resistance pathways. Importantly, coniferous species have been shown to utilise phenolic compounds in their immune responses. Here we also highlight the lack of focus on systemic induced susceptibility in trees, which can be important to forest health. CONCLUSIONS: This review highlights the possible mechanisms of systemic response to infection in woody plant species, their potential applications, and where research may be best focused in future.


Assuntos
Arabidopsis , Traqueófitas , Agricultura Florestal , Árvores , Nicotiana
3.
Photochem Photobiol Sci ; 22(5): 1129-1176, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37310641

RESUMO

Ultraviolet (UV) radiation drives the net production of tropospheric ozone (O3) and a large fraction of particulate matter (PM) including sulfate, nitrate, and secondary organic aerosols. Ground-level O3 and PM are detrimental to human health, leading to several million premature deaths per year globally, and have adverse effects on plants and the yields of crops. The Montreal Protocol has prevented large increases in UV radiation that would have had major impacts on air quality. Future scenarios in which stratospheric O3 returns to 1980 values or even exceeds them (the so-called super-recovery) will tend to ameliorate urban ground-level O3 slightly but worsen it in rural areas. Furthermore, recovery of stratospheric O3 is expected to increase the amount of O3 transported into the troposphere by meteorological processes that are sensitive to climate change. UV radiation also generates hydroxyl radicals (OH) that control the amounts of many environmentally important chemicals in the atmosphere including some greenhouse gases, e.g., methane (CH4), and some short-lived ozone-depleting substances (ODSs). Recent modeling studies have shown that the increases in UV radiation associated with the depletion of stratospheric ozone over 1980-2020 have contributed a small increase (~ 3%) to the globally averaged concentrations of OH. Replacements for ODSs include chemicals that react with OH radicals, hence preventing the transport of these chemicals to the stratosphere. Some of these chemicals, e.g., hydrofluorocarbons that are currently being phased out, and hydrofluoroolefins now used increasingly, decompose into products whose fate in the environment warrants further investigation. One such product, trifluoroacetic acid (TFA), has no obvious pathway of degradation and might accumulate in some water bodies, but is unlikely to cause adverse effects out to 2100.


Assuntos
Poluição do Ar , Ozônio , Humanos , Ozônio Estratosférico , Poluição do Ar/efeitos adversos , Ozônio/análise , Atmosfera , Mudança Climática
4.
Proc Natl Acad Sci U S A ; 117(47): 29363-29370, 2020 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-33229552

RESUMO

A fundamental natural visual task is the identification of specific target objects in the environments that surround us. It has long been known that some properties of the background have strong effects on target visibility. The most well-known properties are the luminance, contrast, and similarity of the background to the target. In previous studies, we found that these properties have highly lawful effects on detection in natural backgrounds. However, there is another important factor affecting detection in natural backgrounds that has received little or no attention in the masking literature, which has been concerned with detection in simpler backgrounds. Namely, in natural backgrounds the properties of the background often vary under the target, and hence some parts of the target are masked more than others. We began studying this factor, which we call the "partial masking factor," by measuring detection thresholds in backgrounds of contrast-modulated white noise that was constructed so that the standard template-matching (TM) observer performs equally well whether or not the noise contrast modulates in the target region. If noise contrast is uniform in the target region, then this TM observer is the Bayesian optimal observer. However, when the noise contrast modulates then the Bayesian optimal observer weights the template at each pixel location by the estimated reliability at that location. We find that human performance for modulated noise backgrounds is predicted by this reliability-weighted TM (RTM) observer. More surprisingly, we find that human performance for natural backgrounds is also predicted by the RTM observer.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Modelos Neurológicos , Reconhecimento Visual de Modelos/fisiologia , Mascaramento Perceptivo/fisiologia , Artefatos , Teorema de Bayes , Humanos , Distribuição Normal , Estimulação Luminosa/métodos
5.
J Vis ; 23(12): 8, 2023 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-37878319

RESUMO

When detecting targets under natural conditions, the visual system almost always faces multiple, simultaneous, dimensions of extrinsic uncertainty. This study focused on the simultaneous uncertainty about target amplitude and background contrast. These dimensions have a large effect on detection and vary greatly in natural scenes. We measured the human performance for detecting a sine-wave target in white noise and natural-scene backgrounds for two levels of prior probability of the target being present. We derived and tested the ideal observer for white-noise backgrounds, a special case of a template-matching observer that dynamically moves its criterion with the background contrast (the DTM observer) and two simpler models with a fixed criterion: the template-matching (TM) observer and the normalized template-matching (NTM) observer that normalizes template response by background contrast. Simulations show that, when the target prior is low, the performance of the NTM observer is near optimal and the TM observer is near chance, suggesting that manipulating the target prior is valuable for distinguishing among models. Surprisingly, we found that the NTM and DTM observers better explain human performance than the TM observer for both target priors in both background types. We argue that the visual system most likely exploits contrast normalization, rather than dynamic criterion adjustment, to deal with simultaneous background contrast and target amplitude uncertainty. Finally, our findings show that the data collected under high levels of uncertainty have a rich structure capable of discriminating between models, providing an alternative approach for studying high dimensions of uncertainty.


Assuntos
Incerteza , Humanos , Probabilidade
6.
J Vis ; 23(10): 16, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37747401

RESUMO

A number of recent studies have been directed at measuring and modeling detection of targets at specific locations in natural backgrounds, a key subtask of visual search in natural environments. A useful approach is to bin natural background patches into joint histograms with bins along specific background dimensions. By measuring psychometric functions in a sparse subset of these bins, it is possible to estimate how the included dimensions jointly affect detectability over the whole space of natural backgrounds. In previous studies, we found that threshold is proportional to the product of the background luminance, contrast, and similarity; a result predicted by a simple template-matching observer with divisive normalization along each of the dimensions. The measure of similarity was the cosine similarity of the amplitude spectra of the target and background (SA)-a phase-invariant measure. Here, we investigated the effect of the cosine similarity of the target and background images (SI|A)-a phase-dependent measure. We found that threshold decreases monotonically with SI|A in agreement with a recent study (Rideaux et al., 2022). In contrast, the template-matching observer predicts threshold to be a U-shaped function of SI|A reaching a minimum when the target and background are orthogonal (SI|A = 0). Surprisingly, when the template-matching observer includes a small amount of intrinsic position uncertainty (measured in a separate experiment) the pattern of thresholds is explained.


Assuntos
Meio Ambiente , Humanos , Incerteza , Psicometria
7.
Mol Pharm ; 19(9): 3394-3404, 2022 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-36001090

RESUMO

Adenosine (ADO) is an endogenous metabolite with immense potential to be repurposed as an immunomodulatory therapeutic, as preclinical studies have demonstrated in models of epilepsy, acute respiratory distress syndrome, and traumatic brain injury, among others. The currently licensed products Adenocard and Adenoscan are formulated at 3 mg/mL of ADO for rapid bolus intravenous injection, but the systemic administration of the saline formulations for anti-inflammatory purposes is limited by the nucleoside's profound hemodynamic effects. Moreover, concentrations that can be attained in the airway or the brain through direct instillation or injection are limited by the volumes that can be accommodated in the anatomical space (<5 mL in humans) and the rapid elimination by enzymatic and transport mechanisms in the interstitium (half-life <5 s). As such, highly concentrated formulations of ADO are needed to attain pharmacologically relevant concentrations at sites of tissue injury. Herein, we report a previously uncharacterized crystalline form of ADO (rcADO) in which 6.7 mg/mL of the nucleoside is suspended in water. Importantly, the crystallinity is not diminished in a protein-rich environment, as evidenced by resuspending the crystals in albumin (15% w/v). To the best of our knowledge, this is the first report of crystalline ADO generated using a facile and organic solvent-free method aimed at localized drug delivery. The crystalline suspension may be suitable for developing ADO into injectable formulations for attaining high concentrations of the endogenous nucleoside in inflammatory locales.


Assuntos
Adenosina Quinase , Adenosina , Adenosina/química , Adenosina/metabolismo , Adenosina Quinase/química , Anti-Inflamatórios , Inibidores Enzimáticos/uso terapêutico , Humanos , Nucleosídeos
8.
Mol Pharm ; 19(7): 2638-2650, 2022 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-35621214

RESUMO

Nanoparticle formulations have long been proposed as subunit vaccine carriers owing to their ability to entrap proteins and codeliver adjuvants. Poly(lactic-co-glycolic acid) (PLGA) remains one of the most studied polymers for controlled release and nanoparticle drug delivery, and numerous studies exist proposing PLGA particles as subunit vaccine carriers. In this work we report using PLGA nanoparticles modified with biotin (bNPs) to deliver proteins via adsorption and stimulate professional antigen-presenting cells (APCs). We present evidence showing bNPs are capable of retaining proteins through the biotin-avidin interaction. Surface accessible biotin bound both biotinylated catalase (bCAT) through avidin and streptavidin horseradish peroxidase (HRP). Analysis of the HRP found that activity on the bNPs was preserved once captured on the surface of bNP. Further, bNPs were found to have self-adjuvant properties, evidenced by bNP induced IL-1ß, IL-18, and IL-12 production in vitro in APCs, thereby licensing the cells to generate Th1-type helper T cell responses. Cytokine production was reduced in avidin precoated bNPs (but not with other proteins), suggesting that the proinflammatory response is due in part to exposed biotin on the surface of bNPs. bNPs injected subcutaneously were localized to draining lymph nodes detectable after 28 days and were internalized by bronchoalveolar lavage dendritic cells and macrophages in mice in a dose-dependent manner when delivered intranasally. Taken together, these data provide evidence that bNPs should be explored further as potential adjuvanting carriers for subunit vaccines.


Assuntos
Biotina , Nanopartículas , Adjuvantes Imunológicos/química , Animais , Avidina , Células Dendríticas , Camundongos , Nanopartículas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Vacinas de Subunidades Antigênicas/metabolismo
9.
Photochem Photobiol Sci ; 21(3): 275-301, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35191005

RESUMO

The Environmental Effects Assessment Panel of the Montreal Protocol under the United Nations Environment Programme evaluates effects on the environment and human health that arise from changes in the stratospheric ozone layer and concomitant variations in ultraviolet (UV) radiation at the Earth's surface. The current update is based on scientific advances that have accumulated since our last assessment (Photochem and Photobiol Sci 20(1):1-67, 2021). We also discuss how climate change affects stratospheric ozone depletion and ultraviolet radiation, and how stratospheric ozone depletion affects climate change. The resulting interlinking effects of stratospheric ozone depletion, UV radiation, and climate change are assessed in terms of air quality, carbon sinks, ecosystems, human health, and natural and synthetic materials. We further highlight potential impacts on the biosphere from extreme climate events that are occurring with increasing frequency as a consequence of climate change. These and other interactive effects are examined with respect to the benefits that the Montreal Protocol and its Amendments are providing to life on Earth by controlling the production of various substances that contribute to both stratospheric ozone depletion and climate change.


Assuntos
Perda de Ozônio , Ozônio , Mudança Climática , Ecossistema , Humanos , Ozônio/química , Ozônio Estratosférico , Raios Ultravioleta
10.
J Opt Soc Am A Opt Image Sci Vis ; 39(4): 690-701, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35471395

RESUMO

Most studies of detection in complex backgrounds have measured and modeled human performance for statistically uniform (stationary) backgrounds. However, natural and medical images have statistical properties that vary over space. We measured detection of various target shapes presented in Gaussian 1/f noise backgrounds that were statistically uniform over space, and in ones that modulated in contrast over space. We find that the pattern of human thresholds is not consistent with the ideal observer but is consistent with a suboptimal observer that performs partial whitening in spatial frequency and whitening (reliability-weighting) in space, and has a small level of intrinsic position uncertainty.


Assuntos
Sensibilidades de Contraste , Processamento de Imagem Assistida por Computador , Humanos , Percepção Visual
11.
J Vis ; 22(5): 6, 2022 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-35467704

RESUMO

Binocular stereo cues are important for discriminating 3D surface orientation, especially at near distances. We devised a single-interval task where observers discriminated the slant of a densely textured planar test surface relative to a textured planar surround reference surface. Although surfaces were rendered with correct perspective, the stimuli were designed so that the binocular cues dominated performance. Slant discrimination performance was measured as a function of the reference slant and the level of uncorrelated white noise added to the test-plane images in the left and right eyes. We compared human performance with an approximate ideal observer (planar matching [PM]) and two subideal observers. The PM observer uses the image in one eye and back projection to predict a test image in the other eye for all possible slants, tilts, and distances. The estimated slant, tilt, and distance are determined by the prediction that most closely matches the measured image in the other eye. The first subideal observer (local planar matching [LPM]) applies PM over local neighborhoods and then pools estimates across the test plane. The second suboptimal observer (local frontoparallel matching [LFM]) uses only location disparity. We find that the ideal observer (PM) and the first subideal observer (LPM) outperforms the second subideal observer (LFM), demonstrating the additional benefit of pattern disparities. We also find that all three model observers can account for human performance, if two free parameters are included: a fixed small level of internal estimation noise, and a fixed overall efficiency scalar on slant discriminability.


Assuntos
Sinais (Psicologia) , Percepção de Profundidade , Olho , Humanos
12.
Sensors (Basel) ; 22(13)2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35808390

RESUMO

Maritime Domain Awareness (MDA) is a strategic field of study that seeks to provide a coastal country with an effective monitoring of its maritime resources and its Exclusive Economic Zone (EEZ). In this scope, a Maritime Monitoring System (MMS) aims to leverage active surveillance of military and non-military activities at sea using sensing devices such as radars, optronics, automatic Identification Systems (AISs), and IoT, among others. However, deploying a nation-scale MMS imposes great challenges regarding the scalability and cybersecurity of this heterogeneous system. Aiming to address these challenges, this work explores the use of blockchain to leverage MMS cybersecurity and to ensure the integrity, authenticity, and availability of relevant navigation data. We propose a prototype built on a permissioned blockchain solution using HyperLedger Fabric-a robust, modular, and efficient open-source blockchain platform. We evaluate this solution's performance through a practical experiment where the prototype receives sensing data from a Software-Defined-Radio (SDR)-based low-cost AIS receiver built with a Raspberry Pi. In order to reduce scalability attrition, we developed a dockerized blockchain client easily deployed on a large scale. Furthermore, we determined, through extensive experimentation, the client optimal hardware configuration, also aiming to reduce implementation and maintenance costs. The performance results provide a quantitative analysis of the blockchain technology overhead and its impact in terms of Quality of Service (QoS), demonstrating the feasibility and effectiveness of our solution in the scope of an MMS using AIS data.


Assuntos
Blockchain , Segurança Computacional , Humanos , Monitorização Fisiológica , Software , Tecnologia
13.
J Therm Spray Technol ; 31(4): 672-684, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37520273

RESUMO

The market needs for increased engine efficiency and environmentally friendly solutions remain the key drivers for the aerospace industry. These efficiency gains will be achieved by meeting the challenges of higher engine operating temperatures, weight reduction, and novel surface solutions for increased component longevity. A critical question to address is if the thermal spray (TS) industry can continue to meet the challenges and demands seen by the airlines and the engine manufacturers. In addition to non-aerospace influences, the COVID-19 pandemic has dramatically affected the landscape of industry growth, not only directly on airlines but also on the associated supply chain. This article reviews this market, its suppliers, and identifies the challenges and opportunities for future growth. Primary focus is on technology and what will be required to bring about reliable, robust, and cost-effective TS solutions into the marketplace. Several issues affecting the global landscape of the aerospace industry are discussed including (1) sustainability, (2) technology, (3) cost of ownership, (4) evolving marketplace, (5) workforce and behavior, and (6) supply chain vitality. An important question to address is if the TS industry can accelerate development with its supply chain and have the ability to commercialize technology more efficiently. Despite the market setbacks from the pandemic and previous issues with the Boeing 737 MAX fleet, the aerospace industry is poised to make significant advancements. These will create new opportunities for thermal spray technology in materials, equipment, and processes. To deliver on them, the implementation of Industry 4.0 along with the investment in human resources is more critical than ever. Based on the findings, the authors project a bright long-term future for both the aerospace and thermal spray industries.

14.
Folia Phoniatr Logop ; 74(4): 271-283, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34644700

RESUMO

INTRODUCTION: Abnormal facial growth is a recognized outcome in cleft lip and palate (CLP), resulting in a concave profile and a class III occlusal status. Maxillary osteotomy (MO) is undertaken to correct this facial deformity, and the surgery can impact speech articulation, although the evidence remains limited and ill-defined for the CLP population. AIMS: The aim of the study was to investigate the impact of MO on the production of the fricatives /f/ and /s/, using perceptual and acoustic analyses, and to explore the nature of speech changes. METHODS: Twenty participants with CLP were seen 0-3 months pre-operatively (T1) and 3 months (T2) and 12 months (T3) after MO. A normal group (N = 20) was similarly recruited. Perceptual speech data was collected according to a validated framework and ratings made on audio and audio-video recordings (VIDRat). Spectral moments were centre of gravity (CG), standard deviation (SD), skewness (SK) and kurtosis (KU). Reliability studies were carried out for all speech analyses. RESULTS: For the CLP group, VIDRat identified dentalization/interdentalization as the main type of pre-operative error for /s/ with a statistically significant improvement over time, χ2(2) = 6.889, p = 0.032. Effect sizes were medium between T1 and T3 (d = 0.631) and small between T2 and T3 (d = 0.194). For the acoustic data, effect sizes were similarly medium between T1 and T2 (e.g., SK, /f/ d = 0.579, /s/ d = 0.642) and small between T1 and T3 across all acoustic parameters. Independent t tests showed mainly statistically significant differences between both groups at all time points with large effect sizes (e.g., T2 CG, t = -4.571, p < 0.001, d =1.581), indicating that /s/ was not normalized post-operatively. For /f/, differences tended to be at T1 with large effect sizes (e.g., CG, t = -2.307, p = 0.028, d = 0.797), reflecting normalization. CONCLUSIONS AND IMPLICATIONS: This is the first speech acoustic study on /f/ for individuals with CLP undergoing MO. The surgery has a positive impact on /f/ and /s/, which appear to stabilize 3 months post-operatively. Speech changes are an automatic and a direct consequence of the physical changes brought about by MO, effecting articulatory re-organization. The results of the study have direct clinical implications for the clinical care pathway for patients with CLP undergoing MO.


Assuntos
Fenda Labial , Fissura Palatina , Osteotomia Maxilar , Acústica , Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Humanos , Fala , Resultado do Tratamento
15.
Circulation ; 142(25): 2459-2469, 2020 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-33076678

RESUMO

BACKGROUND: SERCA [sarco(endo)plasmic reticulum calcium ATPase] is regulated by oxidative posttranslational modifications at cysteine 674 (C674). Because sarcoplasmic reticulum (SR) calcium has been shown to play a critical role in mediating mitochondrial dysfunction in response to reactive oxygen species, we hypothesized that SERCA oxidation at C674 would modulate the effects of reactive oxygen species on mitochondrial calcium and mitochondria-dependent apoptosis in cardiac myocytes. METHODS: Adult rat ventricular myocytes expressing wild-type SERCA2b or a redox-insensitive mutant in which C674 is replaced by serine (C674S) were exposed to H2O2 (100 µmol/Lµ). Free mitochondrial calcium concentration was measured in adult rat ventricular myocytes with a genetically targeted fluorescent probe, and SR calcium content was assessed by measuring caffeine-stimulated release. Mice with heterozygous knock-in of the SERCA C674S mutation were subjected to chronic ascending aortic constriction. RESULTS: In adult rat ventricular myocytes expressing wild-type SERCA, H2O2 caused a 25% increase in mitochondrial calcium concentration that was associated with a 50% decrease in SR calcium content, both of which were prevented by the ryanodine receptor inhibitor tetracaine. In cells expressing the C674S mutant, basal SR calcium content was decreased by 31% and the H2O2-stimulated rise in mitochondrial calcium concentration was attenuated by 40%. In wild-type cells, H2O2 caused cytochrome c release and apoptosis, both of which were prevented in C674S-expressing cells. In myocytes from SERCA knock-in mice, basal SERCA activity and SR calcium content were decreased. To test the effect of C674 oxidation on apoptosis in vivo, SERCA knock-in mice were subjected to chronic ascending aortic constriction. In wild-type mice, ascending aortic constriction caused myocyte apoptosis, LV dilation, and systolic failure, all of which were inhibited in SERCA knock-in mice. CONCLUSIONS: Redox activation of SERCA C674 regulates basal SR calcium content, thereby mediating the pathologic reactive oxygen species-stimulated rise in mitochondrial calcium required for myocyte apoptosis and myocardial failure.


Assuntos
Apoptose , Cálcio/metabolismo , Insuficiência Cardíaca/enzimologia , Mitocôndrias Cardíacas/enzimologia , Miócitos Cardíacos/enzimologia , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Animais , Apoptose/efeitos dos fármacos , Sinalização do Cálcio , Células Cultivadas , Modelos Animais de Doenças , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Peróxido de Hidrogênio/toxicidade , Masculino , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias Cardíacas/genética , Mitocôndrias Cardíacas/patologia , Mutação , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Oxidantes/toxicidade , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , Função Ventricular Esquerda , Remodelação Ventricular
16.
J Neurophysiol ; 125(6): 2125-2134, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33909494

RESUMO

Visual systems evolve to process the stimuli that arise in the organism's natural environment, and hence, to fully understand the neural computations in the visual system, it is important to measure behavioral and neural responses to natural visual stimuli. Here, we measured psychometric and neurometric functions in the macaque monkey for detection of a windowed sine-wave target in uniform backgrounds and in natural backgrounds of various contrasts. The neurometric functions were obtained by near-optimal decoding of voltage-sensitive-dye-imaging (VSDI) responses at the retinotopic scale in primary visual cortex (V1). The results were compared with previous human psychophysical measurements made under the same conditions. We found that human and macaque behavioral thresholds followed the generalized Weber's law as function of contrast, and that both the slopes and the intercepts of the threshold as a function of background contrast match each other up to a single scale factor. We also found that the neurometric thresholds followed the generalized Weber's law with slopes and intercepts matching the behavioral slopes and intercepts up to a single scale factor. We conclude that human and macaque ability to detect targets in natural backgrounds are affected in the same way by background contrast, that these effects are consistent with population decoding at the retinotopic scale by down-stream circuits, and that the macaque monkey is an appropriate animal model for gaining an understanding of the neural mechanisms in humans for detecting targets in natural backgrounds. Finally, we discuss limitations of the current study and potential next steps.NEW & NOTEWORTHY We measured macaque detection performance in natural images and compared their performance to the detection sensitivity of neurophysiological responses recorded in the primary visual cortex (V1), and to the performance of human subjects. We found that 1) human and macaque behavioral performances are in quantitative agreement and 2) are consistent with near-optimal decoding of V1 population responses.


Assuntos
Sensibilidades de Contraste/fisiologia , Percepção de Profundidade/fisiologia , Discriminação Psicológica/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Mascaramento Perceptivo/fisiologia , Córtex Visual Primário/fisiologia , Limiar Sensorial/fisiologia , Animais , Comportamento Animal/fisiologia , Limiar Diferencial , Humanos , Macaca , Especificidade da Espécie , Análise e Desempenho de Tarefas , Imagens com Corantes Sensíveis à Voltagem
17.
Photochem Photobiol Sci ; 20(1): 1-67, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33721243

RESUMO

This assessment by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) provides the latest scientific update since our most recent comprehensive assessment (Photochemical and Photobiological Sciences, 2019, 18, 595-828). The interactive effects between the stratospheric ozone layer, solar ultraviolet (UV) radiation, and climate change are presented within the framework of the Montreal Protocol and the United Nations Sustainable Development Goals. We address how these global environmental changes affect the atmosphere and air quality; human health; terrestrial and aquatic ecosystems; biogeochemical cycles; and materials used in outdoor construction, solar energy technologies, and fabrics. In many cases, there is a growing influence from changes in seasonality and extreme events due to climate change. Additionally, we assess the transmission and environmental effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the COVID-19 pandemic, in the context of linkages with solar UV radiation and the Montreal Protocol.

18.
J Vis ; 21(10): 1, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34468706

RESUMO

Univariate and multivariate normal probability distributions are widely used when modeling decisions under uncertainty. Computing the performance of such models requires integrating these distributions over specific domains, which can vary widely across models. Besides some special cases where these integrals are easy to calculate, there exist no general analytical expressions, standard numerical methods, or software for these integrals. Here we present mathematical results and open-source software that provide (a) the probability in any domain of a normal in any dimensions with any parameters; (b) the probability density, cumulative distribution, and inverse cumulative distribution of any function of a normal vector; (c) the classification errors among any number of normal distributions, the Bayes-optimal discriminability index, and relation to the receiver operating characteristic (ROC); (d) dimension reduction and visualizations for such problems; and (e) tests for how reliably these methods may be used on given data. We demonstrate these tools with vision research applications of detecting occluding objects in natural scenes and detecting camouflage.


Assuntos
Software , Teorema de Bayes , Humanos , Distribuição Normal , Probabilidade , Incerteza
19.
Plant Dis ; 105(12): 4051-4059, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34270912

RESUMO

Wheat blast, caused by Pyricularia oryzae Triticum lineage, is a major constraint to wheat production, mainly in the tropics of Brazil, where severe epidemics have been more frequent. We analyzed disease and wheat yield data from 42 uniform field trials conducted over 9 years (2012 to 2020) to assess whether the percent control and yield response were influenced by fungicide type, region (tropical or subtropical), and year. Six treatments were selected, all evaluated in at least 19 trials. Two fungicides were applied as solo active ingredients (MANCozeb, and TEBUconazole), and four were premixes (AZOXystrobin plus TEBU, TriFLoXystrobin plus PROThioconazole, TFLX plus TEBU, and PYRAclostrobin plus EPOXiconazole). Percent control, calculated from back-transforming estimates by a meta-analysis network model fitted to the log of the means, ranged from 43 to 58%, with all but PYRA plus EPOX showing efficacy >52% on average, not differing among them. The variation in both efficacy and yield response was explained by region, and all but TEBU performed better in the subtropics than in the tropics. Yield response from using three sequential sprays was approximately two times greater in the subtropics (319 to 532 kg/ha) than in the tropics (149 to 241.3 kg/ha). No significant decline in fungicide efficacy or yield response was observed in 9 years of study for any of the fungicides. These results reinforce the need to improve control by adopting an integrated management approach in the tropics given poorer performance and lower profitability, especially for the premixes, than in the subtropics.


Assuntos
Fungicidas Industriais , Brasil , Fungicidas Industriais/farmacologia , Doenças das Plantas/prevenção & controle , Triticum
20.
J Craniofac Surg ; 32(7): 2456-2461, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33852519

RESUMO

BACKGROUND: Maxillary hypoplasia is a common skeletal condition in cleft lip and palate (CLP). Maxillary osteotomy is typically used to reposition the maxilla in CLP with maxillary hypoplasia. Previous studies have suggested that vowel articulations are adjusted postsurgically due to altered vocal tract configuration and articulatory reorganization. This acoustic study aims to investigate whether vowels are normalized postoperatively and to explore the nature of articulatory reorganization. METHODS AND PROCEDURES: A prospective study was conducted to examine the vowel production of a group of individuals with CLP (N = 17) undergoing maxillary osteotomy and a group of normal controls (N = 20), using speech acoustic data. The data were collected at 0 to 3 months presurgery (T1), 3-months (T2), and 12-months (T3) postsurgery. General linear model repeated measures and independent t-tests were undertaken on F1, F2, and vowel space area. RESULTS: General linear model repeated measures revealed no main effects of time for F1 (F [2, 22] = 1.094, P = 0.352), F2 (F [2, 22] = 1.269, P = 0.301), and vowel space area (F [2, 28] = 0.059, P = 0.943). Independent t-tests showed statistically significant differences (P < 0.05) for all acoustic parameters and all vowels between the CLP and the normal groups at all time points. CONCLUSIONS: Vowels were not normalized after maxillary osteotomy despite positive anatomical changes within the oral cavity. Individuals with CLP tended to adjust their vowel articulatory gestures to match presurgical patterns. The nature of articulatory reorganization appears to be prompt, sensory-driven, complete, and permanent.


Assuntos
Fenda Labial , Fissura Palatina , Acústica , Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Humanos , Maxila/cirurgia , Osteotomia Maxilar , Osteotomia de Le Fort , Estudos Prospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA