Gestalt formation promotes awareness of suppressed visual stimuli during binocular rivalry.

Continuous flash suppression leverages binocular rivalry to render observers unaware of a static image for several seconds. To achieve this effect, rapidly flashing noise masks are presented to the dominant eye while a static stimulus is presented to the non-dominant eye. Eventually "breakthrough" occurs, wherein awareness shifts to the static image shown to the non-dominant eye. We tested the hypothesis that Gestalt formation can promote breakthrough. In two experiments, we presented pacman-shaped objects that might or might not align to form illusory Kanizsa objects. To measure the inception of breakthrough, observers were instructed to press a key at the moment of partial breakthrough. After pressing the key, which stopped the trial, observers reported how many pacmen were seen and where they were located. Supporting the Gestalt hypothesis, breakthrough was faster when the pacmen were aligned and observers more often reported pairs of pacmen if they were aligned. To address whether these effects reflected illusory shape perception, a computational model was applied to the pacman report distributions and breakthrough times for an experiment with four pacmen. A full account of the data required an increased joint probability of reporting all four pacmen, suggesting an influence of a perceived illusory cross.

Structuration and deformation of colloidal hydrogels.

The aim of the present paper is to determine the optimum conditions for the formation of homogeneous colloidal silica hydrogels by aggregation and drying processes, avoiding mechanical instabilities at the surface. Aggregation is controlled by adding monovalent salt to the silica nano-particle suspension while the drying of the sol is also modulated by changing the evaporation rate. A phase diagram reveals two regions in the parameter plane, ionic strength versus evaporation rate: a region where the drop undergoes an isotropic shrinkage and forms the required homogeneous gel and a region where mechanical instabilities appear due to the formation of a solid skin at the gel surface. The frontier between these two regions can be determined by equating the following two characteristic times: the gelation time and the time for skin formation. Permeability measurements of the final gel provide an estimate of the drying stress which is compared to the yield stress of the material. In accordance with the determined phase diagram, our study shows that instabilities appear when the drying stress is larger than the yield stress.

Method for the mass production of seedlings of the tropical brown seaweed Sargassum (Phaeophyceae, Ochrophyta).

Farming of Sargassum to produce harvestable crop can be a challenging task to seaweed farmers.•Sexually-produced Sargassum seedlings can be propagated in a hatchery using 140-liter plastic tanks connected with PVC pipes and seawater supply directly pumped from the sea, passing through a filter system.•First step of this method is to collect large amount of fertilized eggs from special branches called receptacles, found at the ends of lateral branches of Sargassum, excised from fertile thalli during its spawning season and collecting their eggs for recruitment into artificial substrate tanks.•Egg collection involves force-releasing the fertilized eggs by vigorous shaking of a small vessel where 100-200 egg-bearing receptacles excised from fertile plants are contained. Each tank can produce up to 2000-3000 seedlings that can supply at least a hectare of farm. Scaling up the production to several hectares of farm is done by simply increasing the number of recruitment tanks and the number of recruitment panels in the hatchery system.

Biogenesis of Autophagosome in Trichomonas vaginalis during Macroautophagy Induced by Rapamycin-treatment and Iron or Glucose Starvation Conditions.

Autophagy is an adaptive response for cell survival in which cytoplasmic components and organelles are degraded in bulk under normal and stress conditions. Trichomonas vaginalis is a parasite highly adaptable to stress conditions such as iron (IR) and glucose restriction (GR). Autophagy can be traced by detecting a key autophagy protein (Atg8) anchored to the autophagosome membrane by a lipid moiety. Our goal was to perform a morphological and cellular study of autophagy in T. vaginalis under GR, IR, and Rapamycin (Rapa) treatment using TvAtg8 as a putative autophagy marker. We cloned tvatg8a and tvatg8b and expressed and purified rTvAtg8a and rTvAtg8b to produce specific polyclonal antibodies. Autophagy vesicles were detected by indirect immunofluorescence assays and confirmed by ultrastructural analysis. The biogenesis of autophagosomes was detected, showing intact cytosolic cargo. TvAtg8 was detected as puncta signal with the anti-rTvAtg8b antibody that recognized soluble and lipid-associated TvAtg8b by Western blot assays in lysates from stress-inducing conditions. The TvAtg8b signal co-localized with the CytoID and lysotracker labeling (autolysosomes) that accumulated after E-64d treatment in GR parasites. Our data suggest that autophagy induced by starvation in T. vaginalis results in the formation of autophagosomes for which TvAtg8b could be a putative autophagy marker.

Evaluating the association of allergies with multiple sclerosis susceptibility risk and disease activity in a pediatric population.

BACKGROUND: Multiple sclerosis (MS) and allergies are both considered to be related to imbalanced Th1 and Th2 immune responses. Previous studies evaluating the relationship between MS and allergies provide conflicting results. OBJECTIVE: To assess allergies and asthma as risk factors for MS and as predictors of MS relapses in a pediatric cohort. METHODS: The environment and genetic risk factors for pediatric MS study is a national case-control project with 16 participating US sites. An environmental questionnaire is used that includes history of allergies in the first five years of life. Case-control data are entered in the pediatric MS Network database and cases at 12 of the 16 sites enter relapse data prospectively. Annualized relapse rate was calculated for patients with follow-up and adjusted for age at disease onset, gender, race, ethnicity, and use of disease-modifying therapy (DMT). RESULTS: We included 271 cases (mean age at disease onset of 15.7years and 62% female) and 418 controls. Relapse data were available for 193 cases. There was no difference in prevalence of allergies or asthma between cases and controls. Patients with food allergies had fewer relapses compared to patients without food allergies (0.14 vs 0.48, p=0.01). CONCLUSIONS: While allergies and asthma are not associated with pediatric MS, cases with food allergies have fewer relapses compared to those without food allergies.

Acute disseminated encephalomyelitis in China, Singapore and Japan: a comparison with the USA.

BACKGROUND AND PURPOSE: Ethnicity-related differences in the incidence of acute disseminated encephalomyelitis (ADEM) and other demyelinating diseases including multiple sclerosis and neuromyelitis optica spectrum disorders have been reported. Little is reported on the influence of ethnicity and geographical location in ADEM. METHODS: Medical records of patients who presented with ADEM (ICD-9 323.61 and 323.81) at large referral hospitals in China, Singapore and Japan (years 1992-2015) were retrospectively reviewed and data were collected in a centralized database. Presenting features and outcomes of ADEM were compared between this multi-country Asian cohort and a uniformly collected US cohort using risk differences and risk ratios. Both cohorts were standardized to a 35% pediatric population to facilitate the comparison. RESULTS: There were 83 Asian patients (48 male, 16 pediatric) followed for a median of 2 (25th-75th percentile 1-10) months. Asian patients exhibited a 26% higher prevalence of spinal cord involvement on magnetic resonance imaging [95% confidence interval (CI) 0-52%; P = 0.05; 63% vs. 37%], a 39% lower prevalence of preceding events (95% CI 12-65%; P < 0.01; 33% vs. 72%) and a 23% lower prevalence of corpus callosum involvement (95% CI 7-39%; P < 0.01; 8% vs. 31%). No difference was observed between the two cohorts in the probability of relapse over the first year after disease onset. CONCLUSIONS: It is hypothesized that the high proportion of Asian patients with spinal cord lesions relates to genetic vulnerability or the higher incidence of neuromyelitis optica spectrum disorders in Asia or could be a spurious association. ADEM presentations most probably vary across geographical settings or ethnicities.

The Glycolytic Enzyme Triosephosphate Isomerase of Trichomonas vaginalis Is a Surface-Associated Protein Induced by Glucose That Functions as a Laminin- and Fibronectin-Binding Protein.

Triosephosphate isomerase of Trichomonas vaginalis (TvTIM) is a 27-kDa cytoplasmic protein encoded by two genes, tvtim1 and tvtim2, that participates in glucose metabolism. TvTIM is also localized to the parasite surface. Thus, the goal of this study was to identify the novel functions of the surface-associated TvTIM in T. vaginalis and to assess the effect of glucose as an environmental factor that regulates its expression and localization. Reverse transcription-PCR (RT-PCR) showed that the tvtim genes were differentially expressed in response to glucose concentration. tvtim1 was overexpressed under glucose-restricted (GR) conditions, whereas tvtim2 was overexpressed under glucose-rich, or high-glucose (HG), conditions. Western blot and indirect immunofluorescence assays also showed that glucose positively affected the amount and surface localization of TvTIM in T. vaginalis Affinity ligand assays demonstrated that the recombinant TvTIM1 and TvTIM2 proteins bound to laminin (Lm) and fibronectin (Fn) but not to plasminogen. Moreover, higher levels of adherence to Lm and Fn were detected in parasites grown under HG conditions than in those grown under GR conditions. Furthermore, pretreatment of trichomonads with an anti-TvTIMr polyclonal antibody or pretreatment of Lm- or Fn-coated wells with both recombinant proteins (TvTIM1r and TvTIM2r) specifically reduced the binding of live parasites to Lm and Fn in a concentration-dependent manner. Moreover, T. vaginalis was exposed to different glucose concentrations during vaginal infection of women with trichomoniasis. Our data indicate that TvTIM is a surface-associated protein under HG conditions that mediates specific binding to Lm and Fn as a novel virulence factor of T. vaginalis.

Comparison of a dedicated children's seizure clinic to mixed general paediatric clinics.

BACKGROUND: In the light of recent recommendations regarding the current management of children with possible epilepsy in the UK, different models of care are compared using an existing validated audit tool. METHODS: The initial clinical assessment process, investigation, management and communication regarding children referred with suspected epilepsy to general paediatric clinics or a paediatric seizure clinic was compared using the British Paediatric Neurology Association (BPNA) audit tool. Results Ninety-three children were included in the comparison. The history and description of the episodes was better documented in the Seizure Clinic (SC). Children's early development (79% vs. 50%) and school performance (86% vs. 42%) were better documented in the SC. Documentation of possible side effects relating to newly prescribed anti-epileptic drugs was poor in both groups (33% vs. 15%). CONCLUSIONS: Differences between models of epilepsy care can be detected using audit tools although there are some methodological limitations of this particular study. Future similar studies as well as informing local practice can add to the debate on the appropriate way forward in improving the care for children with epilepsy.

Experimental measurement of corneal haze after excimer laser keratectomy.

We developed a model of corneal haze following photorefractive keratectomy (PRK) in Iber Braun hens and studied optical properties. The animals underwent PRK for -9.0 diopters of myopia and were divided into groups based on treatment with different wound-healing modulators. At different time points postoperatively, we evaluated haze by slit-lamp microscopy. An experimental device was developed to measure transmittance spatial maps and forward scattering of He-Ne laser light in the excised corneas. Subjective and objective haze measures were compared for each group at the different times. Keratocyte densities were determined by optical microscopy and keratocyte sizes by electron microscopy. The agreement between experimental results and a simple numerical model of scattering suggests that increases in stromal keratocyte density after PRK might explain the degree of corneal haze.

Type 2 tracheal agenesis without tracheoesophageal fistula.

Tracheal agenesis is a potentially lethal congenital anomaly first described by Payne in 1900. It can occur in isolation or in association with tracheoesophageal (TO) or bronchoesophageal (BO) fistula, cardiovascular anomalies, limb deformities, vertebral anomalies and gastrointestinal tract abnormalities. There are 47 reported cases of tracheal agenesis up to 1989; 45 of these were associated with TO fistula. Another 15 cases of tracheal agenesis have been reported since then, and all have been associated with TO fistula. We report only the third case of type 2 tracheal agenesis without TO fistula.

Removable partial denture design considerations where periodontally compromised teeth exist.

Restoration of a periodontally compromised dental arch with a removable partial denture may require one or more design modifications. Multiple rests ensure that adequate vertical support remains in the event primary abutment teeth are lost. An open or closed base can be strategically placed in the maxillary major connector to facilitate the replacement of subsequently lost teeth. The location of finish lines can be modified to provide a smoother resin-to-metal transition when posterior teeth are lost. Wire direct retainers that provide more physiologically acceptable clasping of compromised teeth and that are easily adjusted and added to the prosthesis should be considered.

Factors associated with wrist pain in the young gymnast.

We conducted a cross-sectional survey of 52 nonelite gymnasts (32 girls, 20 boys; average age, 11.8 years) to assess their history of training and wrist pain within the last 6 months. An intensity index was created using the number of training hours per week and the athletes' skill levels. Wrist pain was prevalent in 38 (73%) of the gymnasts. Gymnasts with wrist pain were older (12.6 years versus 9.7 years; P = 0.0002), trained more hours per week (13.5 versus 7.7; P = 0.0002), trained at a higher skill level (P = 0.01), and began training at an older age (7.0 years versus 5.1 years; P = 0.006). Analysis of intensity versus age suggested that a threshold of training intensity may be important in the development of wrist pain. Logistical regression found these factors to be independently associated with wrist pain: intensity (P = 0.036), age > 10 years (P = 0.018), age < 14 years (P = 0.016), and the age of initiation of training (P = 0.020). This study demonstrates that wrist pain is a common problem among nonelite young gymnasts. Training intensity, relative to the age of the participant and the age when training was initiated, appears to be an important determinant of the development of wrist pain in this population.

Design of aberration-balanced high-efficiency focusing holographic gratings.

A volume and phase focusing holographic grating to be used as the principal element of a high-resolution spectrometer has been designed with the aid of a computer. A two-step method was used; first designs were obtained with an aberration-balancing technique, and, in the second step, these early designs are optimized by a ray tracing procedure to obtain aberration-balanced high-efficiency holograms that can be used in highresolution spectroscopy.

Monochromators: versatile design procedure for specific purposes.

A design procedure is described to obtain monochromators for specific applications, which are made from optical devices that can be easily acquired or built. This procedure makes use of a constant angular deviation system consisting of a transmission grating, operating in a symmetrical arrangement, and a flat mirror which makes a fixed angle with it. An analysis of the characteristic parameters of the design and of the constraints which have an effect on them, is presented as well as two examples of applications of the procedure.