1000 resultados para Identificação visual


Relevância:

20.00% 20.00%

Publicador:

Resumo:

A garantia de boas produções em pomares comerciais de macieira depende de uma polinização eficiente, que também está relacionada com a compatibilidade de pólen-estigma, com a coincidência de época de floração e com a capacidade de produção e de germinação de pólen. O objetivo deste estudo foi avaliar a eficiência de diferentes genótipos de macieira como polinizadores da cv. Daiane nas condições climáticas do meio-oeste de Santa Catarina. Plantas de 'Daiane' foram polinizadas a campo com pólen de diversas seleções e cultivares de macieira, com subsequente proteção dos cachos com sacos de papel, por 72 h. Consideraram-se a coincidência de época de floração, a adaptação climática, a taxa de germinação, a reação à mancha foliar de Glomerella, além da frutificação efetiva e do número de sementes por fruto induzido pelas polinizadoras avaliadas. Os tratamentos mais eficientes na polinização da cultivar de macieira Daiane foram as seleções 140/76 e 140/228, respectivamente, que são indicadas para utilização conjugada, visando à maior eficiência na polinização.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: Prominent visual symptoms can present in the visual variant of Alzheimer's disease (VVAD). Ophthalmologists have a significant role to play in the early diagnosis of VVAD. METHODS: We retrospectively reviewed the files of ten consecutive patients diagnosed with VVAD. All patients had a full neuro-ophthalmologic examination, a formal neurological and neuro-psychological testing, and cerebral MRI to confirm diagnosis. In addition, functional neuroimaging was obtained in seven patients. RESULTS: The common primary symptom at presentation with all patients was difficulty with near vision (reading difficulty n = 8, "visual blur" in near vision n = 2), and difficulty writing (n = 3). Following assessment, impaired reading and writing skills were evident in 9/10 and 8/10 patients respectively. Median distance visual acuity was 20/25 and at near the median visual acuity was J6. Partial homonymous visual field defect was detected in 80 % (8/10) of the patients. Color vision was impaired in all patients when tested with Ishihara pseudoisochromatic plates, but simple color naming was normal in 8/9 tested patients. Simultanagnosia was present in 8/10 patients. Vision dysfunction corresponded with cerebral MRI findings where parieto-occipital cortical atrophy was observed in all patients. PET scan (5 patients) or SPECT (2 patients) revealed parieto-occipital dysfunction (hypometabolism or hypoperfusion) in all 7 tested patients CONCLUSIONS: Visual difficulties are prominent in VVAD. Dyslexia, incomplete homonymous hemianopia, preserved color identification with abnormal color vision on Ishihara, and simultanagnosia were all symptoms observed frequently in this patient series. Ophthalmologists should be aware of the possibility of neurodegenerative disorders such as VVAD in patients with unexplained visual complaints, in particular reading difficulties.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O objetivo deste trabalho foi utilizar uma escala de severidade para algumas doenças do maracujazeiro, visando à identificação de fontes de resistência. Foram avaliados 75 acessos de Passiflora spp. em condições de campo, sob alta infecção natural dos patógenos, para a severidade da virose, nas folhas (VIFO), frutos (VIFR) e distribuição na planta (VIPL), bem como para verrugose nos frutos e ramos (VEFR e VERA, respectivamente) e antracnose nos frutos (ANFR). Houve alta variabilidade para resistência às doenças, embora poucos acessos tenham sido classificados como resistentes à VIFO, VIFR e VIPL, sendo que apenas um acesso de P. setacea (BGM237) foi considerado resistente aos três tipos de avaliações para virose. A maioria dos acessos de maracujazeiro- amarelo e roxo possui algum grau de suscetibilidade a um ou outro sintoma da virose. Quanto à VERA, acessos de P. alata e P. cincinnata foram mais resistentes, embora P. alata demonstre maior resistência a VEFR. Alguns acessos de P. edulis comportam-se como moderadamente resistente à VERA e VEFR. A maioria dos acessos de P. alata, P. cincinnata e P. setacea não apresentou sintomas de antracnose nos frutos. A escala de severidade adotada mostrou-se eficiente para a separação dos acessos de maracujazeiro em diferentes classes de resistência a doenças.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

No Brasil, Colletotrichum gloeosporioides é a única espécie associada à antracnose de anonáceas. Contudo, apenas características morfológicas têm sido utilizadas na identificação. Assim, o objetivo do trabalho foi identificar e caracterizar espécies de Colletotrichum que causam a antracnose nas culturas da pinha e da graviola no Estado de Alagoas. Cinquenta e um isolados, obtidos de folhas de pinheira e gravioleira com sintomas típicos da doença, foram coletados em Maceió, Palmeira dos Índios e União dos Palmares. Os isolados foram inoculados em folhas destacadas de ambas as culturas e caracterizados morfologicamente através da morfometria de conídios e apressórios, e molecularmente por meio do sequenciamento da região ITS. Verificou-se que todos os isolados foram patogênicos a ambas as espécies. Na caracterização morfológica, os isolados foram agrupados em três grupos: M1, M2 e M3. O grupo M1 foi formado por 32 isolados com características relacionadas a C. gloeosporioides. No grupo M2, constituído de 15 isolados, predominaram características de C. boninense, enquanto, no grupo M3, composto por quatro isolados, as características foram típicas de C. fragariae. A análise filogenética, da mesma forma, também resultou em três grupos (F1, F2 e F3), os quais, de modo geral, estiveram em concordância com os dados da morfologia. O grupo filogenético F1 concentrou os isolados do grupo morfológico M1 e sequências de referências de C. gloeosporioides e C. fragariae. O grupo F2, que agrupou as sequências de C. boninense, concentrou os isolados do grupo morfológico M2. Finalmente, o grupo F3 incluiu sequências de C. magna e outros quatro isolados desse estudo. Assim, foi possível comprovar que quatro espécies de Colletotrichum são responsáveis pela antracnose em pinheira e gravioleira em Alagoas: C. gloeosporioides, C. boninense, C. fragariae e C. magna.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Nicotine consumption is higher for people within the schizophrenia spectrum compared to controls. This observation supports the self-medication hypothesis, that nicotine relieves symptoms in, for example, schizophrenia patients. We tested whether performance in an endophenotype of schizophrenia (visual backward masking, VBM) is modulated by nicotine consumption in i) smoking and non-smoking schizophrenia patients, their first-degree relatives, and age-matched controls, ii) non-smoking and smoking university students, and iii) non-smoking, early and late onset nicotine smokers. Overall, our results confirmed that VBM deficits are an endophenotype of schizophrenia, i.e., deficits were highest in patients, followed by their relatives, students scoring high in Cognitive Disorganisation, and controls. Moreover, we found i) beneficial effects of chronic nicotine consumption on VBM performance, in particular with increasing age, and ii) little impact of clinical status. alone or in interactionwith nicotine consumption on VBMperformance. Given the younger age of undergraduate students (up to 30 years) versus controls and patients (up to 66 years),we propose that age-dependent VBMdeficits emergewhen schizotypy effects are targeted in populations of a larger age range, but that nicotine consumption might counteract these deficits (supporting the self-medication hypothesis).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PURPOSE: To investigate the functional outcome of eyes with neovascular AMD (nAMD) and subretinal fluid (SRF) refractory to treatment with ranibizumab. METHODS: Retrospective chart review of consecutive treatment-refractory SRF in nAMD despite monthly ranibizumab injections during 12 months or more. Data were evaluated for baseline characteristics, location of the refractory SRF, mean visual acuity (VA) change, number of injections, and timepoint of first complete disappearance of SRF. RESULTS: Forty-five eyes in 44 patients (mean age of 76 years) were included. The mean follow-up was 32.4 months (range 12-73 months). The mean number of injections was 11.6 in the first year and 27.5 over follow-up. The refractory SRF was located subfoveally in 66.7 %. In 12 eyes (26.7 %), complete absorption of SRF was found after a mean of 22.6 months (range, 13-41 months). Mean VA increased by 10.4, 8.2, and 8.6 letters by month 12, 24, and 36, respectively. CONCLUSIONS: Neovascular AMD with SRF refractory to monthly retreatment with ranibizumab may still allow good and maintained visual improvement, even if the fluid is located subfoveally. SRF may progressively absorb under continuous monthly treatment. The necessity to treat refractory SRF with monthly injections could be questioned and would need future investigations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: Best corrected visual acuity (BCVA) of 0.8 or above in AMD patients can sometimes correspond to poor macular function inducing a serious visual handicap. Microperimetry can be used to objectivize this difference. PATIENTS AND METHODS: A retrospective study was undertaken on 233 files of AMD patients of whom 82 had had a microperimetry. BCVA was compared with microperimetry performance. All examinations were performed in an identical setting by the same team of 3 persons. RESULTS: Among the 82 patients included, 32 (39.0%) had a BCVA equal to or above 0.8 even though their microperimetry performance was lower than 200/560 db. 10 of them (12.2% of total) had an even poorer microperimetry below 120/560 db indicating poor macular function. CONCLUSIONS: More than a third of the AMD patients had a bad or very bad microperimetry performance in parallel with a good visual acuity. Microperimetry is a valuable tool to assess and follow real macular function in AMD patients when visual acuity alone can be misleading.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PURPOSE: Laparoscopic surgery represents specific challenges, such as the reduction of a three-dimensional anatomic environment to two dimensions. The aim of this study was to investigate the impact of the loss of the third dimension on laparoscopic virtual reality (VR) performance. METHODS: We compared a group of examinees with impaired stereopsis (group 1, n = 28) to a group with accurate stereopsis (group 2, n = 29). The primary outcome was the difference between the mean total score (MTS) of all tasks taken together and the performance in task 3 (eye-hand coordination), which was a priori considered to be the most dependent on intact stereopsis. RESULTS: The MTS and performance in task 3 tended to be slightly, but not significantly, better in group 2 than in group 1 [MTS: -0.12 (95 % CI -0.32, 0.08; p = 0.234); task 3: -0.09 (95 % CI -0.29, 0.11; p = 0.385)]. The difference of MTS between simulated impaired stereopsis between group 2 (by attaching an eye patch on the adominant eye in the 2nd run) and the first run of group 1 was not significant (MTS: p = 0.981; task 3: p = 0.527). CONCLUSION: We were unable to demonstrate an impact of impaired examinees' stereopsis on laparoscopic VR performance. Individuals with accurate stereopsis seem to be able to compensate for the loss of the third dimension in laparoscopic VR simulations.