[Variation in Phosphorus Concentration and Flux at Zhutuo Section in the Yangtze River and Source Apportionment]

Phosphorus (P) is a pollutant of great concern in the Yangtze River Basin. The Xiangjiaba Reservoir and Xiluodu Reservoir on the lower reach of the Jinsha River began to operate in 2012 and 2013, respectively, which greatly changed the concentrations of suspended sediment and characteristics of P form and transport in the reservoirs and the downstream reach from Yibin to Jiangjin of the Yangtze River. The Zhutuo section is representative in the water quality of the Yibin-Jiangjin reach, which can not only reflect the comprehensive effects of the formation of the two reservoirs and changes in the aquatic environment in the Min-Tuo Rivers but also reflect the quality of water flowing into the Three Gorges Reservoir. The runoff, concentrations and fluxes of suspended sediments (SS), and P concentrations and fluxes at Zhutuo section were studied during 2002-2019, and the source of P was apportioned based on the principle of river base flow. The results showed that in the past 18 years, the concentrations and fluxes of total phosphorus (TP) and particulate phosphorus (PP) at Zhutuo section in the wet season were higher than those in the level and dry seasons; the rule of positive correlation between PP and SS concentrations remained unchanged. From 2002 to 2019, the concentrations and fluxes of TP, PP, and dissolved P (DP) generally increased first and then decreased, and the operation of the Xiangjiaba Reservoir was a time node for the trend turning. Compared with that in the period from 2002-2012, the SS concentration and flux decreased by 94% and 77%, TP and PP concentrations decreased by 46% and 70%, and TP and PP fluxes decreased by 58% and 74%, respectively, during 2014-2019. The decline mainly occurred in the wet season, followed by that in the level season. After the formation of the two reservoirs, the relationship between water and sediment and the form of P greatly changed, and the proportion of DP in TP increased significantly, whereas the proportion of PP was the opposite. The TP pool in overlying water in the dry and level seasons shifted from mainly particulate to mainly dissolved. The change in water and sediment conditions was the main driving force for the significant change in P concentration, flux, and form. Before the operation of the Xiangjiaba Reservoir, the Jinsha River was the maximum contributor to the whole and diffuse source part of the TP load at Zhutuo section among the contributing catchment sub-basins; however, the Minjiang River became the largest contributor after the operation. The average TP load at Zhutuo section from 2017-2019 was 3.575×104 t·a-1 (after deducting the natural background value), of which the contribution of diffuse sources and point sources accounted for 68% and 32%, respectively. The Minjiang River represented 49%, 43%, and 62% of the total TP load, diffuse source TP load, and point source TP load at Zhutuo section, respectively. Considering the load contribution and pollution intensity, the key area for P pollution control in the area upstream of the Three Gorges Reservoir was the Min-Tuo River Basin.

Feasibility of Endotracheal Extubation Evaluation Form in Predicting Successful Extubation in Neonatal Intensive Care Units: A Retrospective Study

Given the limited availability of evidence-based methods for assessing the timing of extubation in intubated preterm infants, we aimed to standardize the extubation protocol in this single-center, retrospective study. To accomplish this, we established an extubation evaluation form to assess the suitability of extubation in preterm infants. The form comprises six indicators: improved clinical condition, spontaneous breath rate ≥ 30 breaths per minute, peak inspiratory pressure (PIP) ≤ 15 cmH₂O, fraction of inspired oxygen (FiO₂) ≤ 30%, blood pH ≥ 7.2, and mixed venous carbon dioxide tension (PvCO₂) < 70 mmHg. Each positive answer is given one point, indicating a maximum of six points. We enrolled 41 intubated preterm infants (gestational age < 32 weeks, birth weight < 1500 g) who were receiving mechanical ventilation support for over 24 h. Among them, 35 were successfully extubated, and 6 were not. After completing the extubation evaluation form and adjusting for birth weight and postextubation device, we observed that the total score of the form was significantly associated with successful extubation; the higher the score, the greater the chance of successful extubation. Thus, we infer that the extubation evaluation form may provide a more objective standard for extubation assessment in preterm infants.

Construction of a Form for Users of the Child Welfare System Based on the Delphi Method

Professionals in charge of designing individualized plans for children and adolescents in the child welfare system often lack the necessary information, either because it has not been systematically collected or because there are doubts about the reliability of the data obtained. The lack of consensual and validated instruments that gather the necessary information has led to the development of a rigorous and effective form, based on the Delphi methodology, aimed at obtaining an exhaustive knowledge of the characteristics of children and adolescents under the child welfare system. Once a consensus of different specialists approved the hetero-informed form, it was completed by 41 professionals working in residential care facilities for 307 children and adolescents. It consists of 66 items grouped into six dimensions: general information, school/work situation, child welfare system history, family visitation history, biological family information, and experiences of sexual abuse. During its construction and validation, a panel of experts analyzed its format and content during the different phases. Most of the items showed good performance, and professionals highlighted their ease of use and relevance. The method used ensured the content validity of this form. This instrument has proven to be a useful and effective tool for collecting sociodemographic information on children and adolescents in the child welfare system, which may improve their conditions.

Form-Dependent Toxicity of Silver Nanomaterials in Rainbow Trout Gills

The toxicity of the form of nanoparticles is presently not well understood. The purpose of this study consists in comparing the toxicity of various forms of silver nanoparticles (nAg) in juvenile rainbow trout Oncorhynchus mykiss. Juveniles were exposed to various forms of polyvinyl-coated nAg of similar size for 96 h at 15 °C. After the exposure period, the gills were isolated and analyzed for Ag uptake/distribution, oxidative stress, glucose metabolism, and genotoxicity. Higher levels of Ag were detected in gills in fish exposed to dissolved Ag followed by spherical, cubic, and prismatic nAg. Size-exclusion chromatography of gill fractions revealed that the dissolution of nAg was observed for all forms of nAg where prismatic nAg released more important levels of Ag in the protein pool as in fish exposed to dissolved Ag as well. The aggregation of nAg was more important for cubic nAg in respect of the other forms of nAg. The data revealed that lipid peroxidation was closely associated with protein aggregation and viscosity. Biomarkers revealed changes in lipid/oxidative stress and genotoxicity, which were related to the loss of protein aggregation and inflammation (NO₂ levels), respectively. In general, the observed effects were found for all forms of nAg where the effects from prismatic nAg were generally higher than for spherical and cubic nAg. The strong relationship between genotoxicity and inflammation response suggests the participation of the immune system in the observed responses of juvenile fish gills.

Design of biopolymer-based hemostatic material: Starting from molecular structures and forms

Uncontrolled bleeding remains as a leading cause of death in surgical, traumatic, and emergency situations. Management of the hemorrhage and development of hemostatic materials are paramount for patient survival. Owing to their inherent biocompatibility, biodegradability and bioactivity, biopolymers such as polysaccharides and polypeptides have been extensively researched and become a focus for the development of next-generation hemostatic materials. The construction of novel hemostatic materials requires in-depth understanding of the physiological hemostatic process, fundamental hemostatic mechanisms, and the effects of material chemistry/physics. Herein, we have recapitulated the common hemostatic strategies and development status of biopolymer-based hemostatic materials. Furthermore, the hemostatic mechanisms of various molecular structures (components and chemical modifications) are summarized from a microscopic perspective, and the design based on them are introduced. From a macroscopic perspective, the design of various forms of hemostatic materials, e.g., powder, sponge, hydrogel and gauze, is summarized and compared, which may provide an enlightenment for the optimization of hemostat design. It has also highlighted current challenges to the development of biopolymer-based hemostatic materials and proposed future directions in chemistry design, advanced form and clinical application.

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Biopolymers possess sound biocompatibility, biodegradability and bioactivity for the design of hemostatic materials.

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Molecular structure designs including component and chemical modification are summarized from a microscopic perspective.

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Design of various forms of hemostatic materials is discussed and compared synthetically from a macroscopic perspective.

Clinical and Laboratory Features of Enteric Fever in Children and Antibiotic Sensitivity Pattern in a Tertiary Care Hospital of a Low- and Middle-Income Country

BACKGROUND

Globally, enteric fever (EF) significantly gives rise to an appalling death toll. It is an endemic illness in Bangladesh and South Asia. The condition manifests in a wide range of clinical features in children. Nowadays, antibiotic resistance is an international stumbling block that hampers the appropriate treatment and outcome of EF.

OBJECTIVE

The study evaluated the clinical and laboratory characteristics and antibiotic sensitivity pattern of Salmonella enterica in children.

METHODS

This prospective research was conducted at Delta Medical College and Hospital, Dhaka, Bangladesh, from January 2017 to December 2019. A total of 200 pediatric cases of EF were included in this study who were either culture positive or had significantly raised Widal test titer for Salmonella with suggestive clinical features.

RESULTS

All the patients had a fever, and most had coated tongue, vomiting, abdominal pain, organomegaly, and diarrhea. Among the selected 200 cases of EF, 43.5% were Salmonella typhi culture-positive. A high erythrocyte sedimentation rate (ESR) was observed in a substantial number (53%) of patients. Ceftriaxone was the most sensitive (100%) antibiotic through laboratory analysis, followed by cefotaxime (95.1%). Among the oral antibiotics used, cefixime (92.8%) was the most sensitive.

CONCLUSION

EF in children can present with varied clinical manifestations. Selective antibiotic treatment according to sensitivity patterns is crucial for effective illness management and will reduce morbidity and mortality in the pediatric population.

Quality of written informed consent forms for electroconvulsive therapy in Australia: a comparative analysis

OBJECTIVES

We compared the quality of the written informed consent forms for electroconvulsive therapy (ECT) in Australian jurisdictions.

METHOD

For this comparative audit-type study, a checklist was developed to compare informed consent forms from different jurisdictions. The main information sources for consent forms were government health department websites and Google. The directors of clinical services were contacted if a consent form was not available through a web source.

RESULTS

Majority of the informed consent forms covered information about ECT, general anaesthesia and alternative treatments, supports available for decision making, and a reference to the right to withdraw consent. Missing information affected information areas such as likely outcome if no ECT, lack of guaranteed response and cultural and linguistic supports.

CONCLUSIONS

A standardised consent form that can be used across all jurisdictions can help improve the ECT practice.

[Particle Design Strategies for Developing Patient Centric Dosage Form Preparations]

Novel dosage form designs aiming at patient centric drug therapy are summarized here based on my carrier research in this field. The common key word for this research is particle design. The topics will be divided into two parts, based on the type of particle: coarse particles (powder) and colloidal particles. The former includes the preparation and characterization of functional particles prepared using a spray dryer. Solid dispersions, solvent deposition particles and dry emulsion systems are described. Polymer coated liposomes are described as a useful drug delivery carrier in several administration routes. As chitosan, a mucoadhesive polymer, was used as a coating polymer, the resultant chitosan-coated liposome was found to work as a good carrier for peptide drugs such as insulin and calcitonin in the gastrointestinal tract after oral administration. In another administration route (inhalation), polymer-coated liposomes enhanced the absorption of the drugs. Liposomal carriers applied to the surface of the eye as eye drops are able to deliver drugs to the posterior part of the eye, such as the retina. As a typical example of patient centric dosage form design, particle designs for the preparation of orally disintegrating tablets and films were introduced in one of our recent studies on oral dosage form design.

Differences in dental arch characteristics between genders in patients with suspected condylar hyperplasia in a North Sumatra subpopulation: a cross-sectional study

Background: Condylar Hyperplasia (CH) is a self-limiting mandibular condyle disorder that shows asymmetry progress in conjunction with associated occlusal changes as long as condylar growth is still active and leads to facial asymmetry. This study aimed to analysis the difference of dental arch characteristics  based on genders in orthodontic patients with suspected CH in a North Sumatra subpopulation.

Methods: This is a retrospective study of suspected CH patient’s clinical records who sought for the initial orthodontic treatment between January 2015 to March 2019. Patient with facial asymmetry (based on photography, posterior crossbite and midline deviation), the positive temporomandibular joint disorder in functional analysis, and no history of facial trauma were included in the study. Dental arch asymmetry was based on the measurement of dental midline deviation, canine tip in the dental arch, the distance of the upper canines from the palatal suture, and inter canine distance. The evaluation of dental arch was achieved by comparing arch width and length.

Results: There was a significant difference (p<0.05) of upper canine distance from the palatal suture in female patients when evaluating upper dental arch asymmetry. There was a moderate correlation (r=0.379) in midline deviation between upper and lower dental arch. The dimension and dental arch form were mid and flat, and there was moderate correlation (r=0.448) between the upper and lower dental arch form in these suspected CH patients.

Conclusion: Indeed skeletal asymmetry, the evaluation of the dental arch characteristic symmetry and arch form showed asymmetric occlusal characteristics in orthodontics patient with suspected  CH in the North Sumatera subpopulation. In treating these patients, we recommend the plaster cast evaluation as essential and routine procedure in order to understand the complexity of occlusal change due to active growth of condylar and limitation in radiography evaluation.

[Temporal and Spatial Distribution Characteristics and Difference Analysis of Nitrogen and Phosphorus in Daihai Lake]

Based on the historical monitoring survey data from 2018 to 2019, the temporal and spatial distribution characteristics and main influencing factors of nitrogen and phosphorus in the overlying water in Daihai Lake were analyzed, and the differences of the temporal and spatial distribution were discussed. The results showed that the content of total nitrogen and total phosphorus in the overlying water was at a high level, especially the total nitrogen content was obviously higher than that in other lakes in China. The content of total nitrogen ranged from 3.29 mg·L^-1 to 4.99 mg·L^-1, with a mean value of (3.93±0.33) mg·L^-1; the content of total phosphorus ranged from 0.063 mg·L^-1 to 0.163 mg·L^-1, with a mean value of (0.111±0.023) mg·L^-1. In spring and summer, the content of total nitrogen and total phosphorus in the overlying deep water from the middle of the lake was significantly higher than that in the surrounding area. In autumn, the contents decreased from east to west, and in winter, the contents in the shallow water of the southern area were higher than that in the northern area. Nitrogen and phosphorus in the overlying water were mainly in the dissolved state, and the proportions of total dissolved nitrogen and phosphorus were 86.62% and 77.84%, respectively. The dissolved nitrogen was dominated by nitrate, whereas dissolved phosphorus was dominated by organic phosphorus. The concentration of lake water and the release of endogenous nutrient salts are the main reasons for the high total nitrogen and phosphorus. To prevent further deterioration of water quality, it is suggested to carry out endogenous treatment and ecological restoration in combination with engineering measures.

Dorsal-movement and ventral-form regions are functionally connected during visual-speech recognition

Faces convey social information such as emotion and speech. Facial emotion processing is supported via interactions between dorsal-movement and ventral-form visual cortex regions. Here, we explored, for the first time, whether similar dorsal-ventral interactions (assessed via functional connectivity), might also exist for visual-speech processing. We then examined whether altered dorsal-ventral connectivity is observed in adults with high-functioning autism spectrum disorder (ASD), a disorder associated with impaired visual-speech recognition. We acquired functional magnetic resonance imaging (fMRI) data with concurrent eye tracking in pairwise matched control and ASD participants. In both groups, dorsal-movement regions in the visual motion area 5 (V5/MT) and the temporal visual speech area (TVSA) were functionally connected to ventral-form regions (i.e., the occipital face area [OFA] and the fusiform face area [FFA]) during the recognition of visual speech, in contrast to the recognition of face identity. Notably, parts of this functional connectivity were decreased in the ASD group compared to the controls (i.e., right V5/MT-right OFA, left TVSA-left FFA). The results confirmed our hypothesis that functional connectivity between dorsal-movement and ventral-form regions exists during visual-speech processing. Its partial dysfunction in ASD might contribute to difficulties in the recognition of dynamic face information relevant for successful face-to-face communication.

Integration of Motion and Form Cues for the Perception of Self-Motion in the Human Brain

When moving around in the world, the human visual system uses both motion and form information to estimate the direction of self-motion (i.e., heading). However, little is known about cortical areas in charge of this task. This brain-imaging study addressed this question by using visual stimuli consisting of randomly distributed dot pairs oriented toward a locus on a screen (the form-defined focus of expansion [FoE]) but moved away from a different locus (the motion-defined FoE) to simulate observer translation. We first fixed the motion-defined FoE location and shifted the form-defined FoE location. We then made the locations of the motion- and the form-defined FoEs either congruent (at the same location in the display) or incongruent (on the opposite sides of the display). The motion- or the form-defined FoE shift was the same in the two types of stimuli, but the perceived heading direction shifted for the congruent, but not for the incongruent stimuli. Participants (both sexes) made a task-irrelevant (contrast discrimination) judgment during scanning. Searchlight and ROI-based multivoxel pattern analysis revealed that early visual areas V1, V2, and V3 responded to either the motion- or the form-defined FoE shift. After V3, only the dorsal areas V3a and V3B/KO responded to such shifts. Furthermore, area V3B/KO shows a significantly higher decoding accuracy for the congruent than the incongruent stimuli. Our results provide direct evidence showing that area V3B/KO does not simply respond to motion and form cues but integrates these two cues for the perception of heading.SIGNIFICANCE STATEMENT Human survival relies on accurate perception of self-motion. The visual system uses both motion (optic flow) and form cues for the perception of the direction of self-motion (heading). Although human brain areas for processing optic flow and form structure are well identified, the areas responsible for integrating these two cues for the perception of self-motion remain unknown. We conducted fMRI experiments and used multivoxel pattern analysis technique to find human brain areas that can decode the shift in heading specified by each cue alone and the two cues combined. We found that motion and form cues are first processed in the early visual areas and then are likely integrated in the higher dorsal area V3B/KO for the final estimation of heading.

Postprandial Glycemic and Insulinemic Effects of the Addition of Aqueous Extracts of Dried Corn Silk, Cumin Seed Powder or Tamarind Pulp, in Two Forms, Consumed with High Glycemic Index Rice

Several plant-based traditional ingredients in Asia are anecdotally used for preventing and/or treating type 2 diabetes. We investigated three such widely consumed ingredients, namely corn silk (CS), cumin (CU), and tamarind (TA). The aim of the study was to determine the effects of aqueous extracts of these ingredients consumed either as a drink (D) with high-glycemic-index rice or added to the same amount of rice during cooking (R) on postprandial glycemia (PPG), insulinemia (PPI), and blood pressure (BP), over a 3 h measurement period. Eighteen healthy Chinese men (aged 37.5 ± 12.5 years, BMI 21.8 ± 1.67 kg/m²) took part in a randomized crossover trial, each completing up to nine sessions. Compared to the control meal (plain rice + plain water), the addition of test extracts in either form did not modulate PPG, PPI, or BP. However, the extracts when added within rice while cooking gave rise to significantly lower PPI than when consumed as a drink (p < 0.01). Therefore, the form of consumption of phytochemical-rich ingredients can differentially modulate glucose homeostasis. This study also highlights the need for undertaking randomized controlled clinical trials with traditional foods/components before claims are made on their specific health effects.

The Pupillary Response to the Unknown: Novelty Versus Familiarity

Object recognition is a type of perception that enables observers to recognize familiar shapes and categorize them into real-world identities. In this preregistered study, we aimed to determine whether pupil size changes occur during the perception and recognition of identifiable objects. We compared pupil size changes for familiar objects, nonobjects, and random noise. Nonobjects and noise produced greater pupil dilation than familiar objects. Contrary to previous evidence showing greater pupil dilation to stimuli with more perceptual and affective content, these results indicate a greater pupil dilation to stimuli that are unidentifiable. This is consistent with the relative salience of novelty compared to familiarity at the physiological level driving the pupil response.

Shape from Contour: Computation and Representation

The human visual system reliably extracts shape information from complex natural scenes in spite of noise and fragmentation caused by clutter and occlusions. A fast, feedforward sweep through ventral stream involving mechanisms tuned for orientation, curvature, and local Gestalt principles produces partial shape representations sufficient for simpler discriminative tasks. More complete shape representations may involve recurrent processes that integrate local and global cues. While feedforward discriminative deep neural network models currently produce the best predictions of object selectivity in higher areas of the object pathway, a generative model may be required to account for all aspects of shape perception. Research suggests that a successful model will account for our acute sensitivity to four key perceptual dimensions of shape: topology, symmetry, composition, and deformation.

[Characteristics of Organic Phosphorus Fractions in the Sediments of the Black Water Aggregation in Lake Taihu]

Potential release of phosphorus in lake sediments depends largely on the fractions and distribution of organic phosphorus. MaoDu was chosen as the research area in the west of Lake Taihu. The chemical forms of the surface sediments were investigated by the Ivannoff extraction methods. The results showed that the main organic phosphorus form of sediments at different sampling places was humic acid-OP. It accounted for 35% of the total organic phosphorus. Horizontal distribution: Total organic phosphorus content from the shore to the middle of total showed a trend of rising after decline; vertical distribution: Total organic phosphorus content was the lowest in 2-6 cm and the highest in 4-8 cm. Various phosphorus content followed the order of humic acid-OP > residual-OP > HCl-OP > fulvic acid-OP; the relative content of NaHCO₃-OP in the total organic phosphorus content showed a trend of rising followed by reduction and then rising again from the shore to the middle, cyanobacteria residue deposition increased the content of NaHCO₃-OP in sediment. Contents of NaHCO₃-OP and humic acid-OP both first reduced, then increased and finally reduced in the vertical distribution, the content of NaHCO₃-OP was the lowest in 4-6 cm and humic acid-OP was the highest in 4-8 cm. HCl-OP and fulvic-OP decreased with increasing depth in the vertical distribution. The content of residual-OP showed stable tendency in the vertical direction and was about 45 μg·g^-1. Labile OP and pH, DO, the depth of water were significantly negatively correlated, OM and NaOH-Pi were significantly correlated with total organic phosphorus, labile OP, moderately labile OP and nonlabile OP. Three components of organic phosphorus had bio-availability and played an important role in lake eutrophication. The increase of the content of labile OP might promote the black water aggregation (BWA) in cyanobacteria accumulation.

The Power of Shape: How Shape of Node-Link Diagrams Impacts Aesthetic Appreciation and Triggers Interest

Positive effects of aesthetically appreciated designs have long been studied and confirmed since the 19th century: such designs are more enjoyable, they are more forgivable for glitches and can increase users' performance. In the field of information visualization, studies of aesthetics are still a niche approach. In the current study, we aim to specifically understand which parameters in a visualization of node-link diagrams make them aesthetically pleasing-an important extension to already existing research on usability and readability aspects. We investigated how the shape of the outline of such diagrams influences the aesthetic judgments on two of the most important dimensions of aesthetic appeal: beauty and interest. We employed different outlines to node-link diagrams and compared them with uniformly filled shapes, varying two important variables typically impacting aesthetics: complexity and curvature. This was done for a short (100 ms) and ad libitum presentation time. Diagrams with curvier outlines were perceived as more beautiful, while diagrams with more complex outlines were considered to be more interesting. These dependencies already exist for presaccadic perception (100 ms) and are slightly stronger for unlimited presentation time. We also found that curvature is a predictor for beauty only for unlimited presentation time. Aesthetic appeal was very similar for diagrams and pure shapes, so many results from fundamental research on aesthetics can potentially be transferred to the community of network visualization, assisting to improve visualizations also in aesthetic regards.

Points and Stripes: A Novel Technique for Masking Biological Motion Point-Light Stimuli

Human articulated motion can be readily recognized robustly even from impoverished so-called point-light displays. Such sequence information is processed by separate visual processing channels recruiting different stages at low and intermediate levels of the cortical visual processing hierarchy. The different contributions that motion and form information make to form articulated, or biological, motion perception are still under investigation. Here we investigate experimentally whether and how specific spatio-temporal features, such as extrema in the motion energy or maximum limb expansion, indicated by the lateral and longitudinal extension, constrain the formation of the representations of articulated body motion. In order to isolate the relevant stimulus properties we suggest a novel masking technique, which allows to selectively impair the ankle information of the body configuration while keeping the motion of the point-light locations intact. Our results provide evidence that maxima in feature channel representations, e.g., the lateral or longitudinal extension, define elemental features to specify key poses of biological motion patterns. These findings provide support for models which aim at automatically building visual representations for the cortical processing of articulated motion by identifying temporally localized events in a continuous input stream.

Stroboscopic Vision When Interacting With Multiple Moving Objects: Perturbation Is Not the Same as Elimination

Motivated by recent findings of improved perceptual processing and perceptual-motor skill following stroboscopic vision training, the current study examined the performance and acquisition effects of stroboscopic vision methods that afford a different visual experience. In Experiment 1, we conducted a within-subject design study to examine performance of a multiple object tracking (MOT) task in different stroboscopic vision conditions (Nike Vapor Strobe^®, PLATO visual occlusion, and intermittent display presentation) operating at 5.6, 3.2, or 1.8 Hz. We found that participants maintained MOT performance in the Vapor Strobe condition irrespective of strobe rate. However, MOT performance deteriorated as strobe rate was reduced in the other two stroboscopic vision conditions. Moreover, at the lowest strobe rate (1.8 Hz) there was an increase in probe reaction time, thus indicating an increased attentional demand due to the stroboscopic vision. In Experiment 2, we conducted a mixed design study to examine if practice in different stroboscopic vision conditions (Nike Vapor Strobe^® and PLATO visual occlusion) influenced acquisition of a novel precision-aiming task [i.e., multiple object avoidance (MOA) task] compared to a normal vision group. Participants in the PLATO visual occlusion group exhibited worse performance during practice than the Vapor Strobe and normal vision groups. At post-test, the Vapor Strobe group demonstrated greater success and reduced end-point error than the normal vision and PLATO groups. We interpret these findings as showing that both an intermittent perturbation (Nike Vapor Strobe^®) and elimination (PLATO visual occlusion and intermittent display presentation) of visual motion and form are more attention demanding (Experiment 1), however, the intermittent perturbation, but not elimination, of visual motion and form can facilitate acquisition of perceptual-motor skill (Experiment 2) in situations where it is necessary to maintain and update a spatio-temporal representation of multiple moving objects.

Importance of informed consent defined by General Surgery Associations in Turkey

Objective

Informed consent is a term based on the idea that every individual has the right to know every medical intervention that is going to be performed on their own body and to learn the issues that she/he may encounter in case of refusal of intervention, and it also defines the protection of personal rights under the guarantee of law.

Material and Methods

The website of Turkish Surgical Association and 25 different websites of surgical associations were evaluated according to general surgery association guide, which was published by the Turkish Surgical Association in 2011.

Results

Four websites of those surveyed include informed consent sections and these were evaluated. A total of 44 informed consent forms were included in this study. Of these, 29 were in Turk Colon and Rectum Surgery Association, 8 were in Turkish Surgery Association, 5 were in Turk Hepatopancreaticobilier Surgery Association, and 4 were in Endocrine Surgery Association. These informed consent forms were evaluated with regard to the aforementioned criteria. The results and also the distribution according to the associations were summarized. A common feature of the informed consent forms was that all of them included the risks of the intervention/operation and complications to be carried out. On the contrary, none of them included approximate time of surgery, information about surgeons, issues that patients should care about before surgery, the section that permits the use of data for scientific purpose, and the time of signing the informed consent form.

Conclusion

We believe that in this context the regulation of informed consent by sub-specialization associations under the flag of Turkish Surgical Association is a very important matter and will standardize informed consents; websites of the associations will be easier to access, and this will be as beneficial for physicians as the patients and also will protect the physicians in probable trials.

Form and Function in Human Song

Humans use music for a variety of social functions: we sing to accompany dance, to soothe babies, to heal illness, to communicate love, and so on. Across animal taxa, vocalization forms are shaped by their functions, including in humans. Here, we show that vocal music exhibits recurrent, distinct, and cross-culturally robust form-function relations that are detectable by listeners across the globe. In Experiment 1, internet users (n = 750) in 60 countries listened to brief excerpts of songs, rating each song's function on six dimensions (e.g., "used to soothe a baby"). Excerpts were drawn from a geographically stratified pseudorandom sample of dance songs, lullabies, healing songs, and love songs recorded in 86 mostly small-scale societies, including hunter-gatherers, pastoralists, and subsistence farmers. Experiment 1 and its analysis plan were pre-registered. Despite participants' unfamiliarity with the societies represented, the random sampling of each excerpt, their very short duration (14 s), and the enormous diversity of this music, the ratings demonstrated accurate and cross-culturally reliable inferences about song functions on the basis of song forms alone. In Experiment 2, internet users (n = 1,000) in the United States and India rated three contextual features (e.g., gender of singer) and seven musical features (e.g., melodic complexity) of each excerpt. The songs' contextual features were predictive of Experiment 1 function ratings, but musical features and the songs' actual functions explained unique variance in function ratings. These findings are consistent with the existence of universal links between form and function in vocal music.

Growth patterns for shape-shifting elastic bilayers

Inspired by the differential-growth-driven morphogenesis of leaves, flowers, and other tissues, there is increasing interest in artificial analogs of these shape-shifting thin sheets made of active materials that respond to environmental stimuli such as heat, light, and humidity. But how can we determine the growth patterns to achieve a given shape from another shape? We solve this geometric inverse problem of determining the growth factors and directions (the metric tensors) for a given isotropic elastic bilayer to grow into a target shape by posing and solving an elastic energy minimization problem. A mathematical equivalence between bilayers and curved monolayers simplifies the inverse problem considerably by providing algebraic expressions for the growth metric tensors in terms of those of the final shape. This approach also allows us to prove that we can grow any target surface from any reference surface using orthotropically growing bilayers. We demonstrate this by numerically simulating the growth of a flat sheet into a face, a cylindrical sheet into a flower, and a flat sheet into a complex canyon-like structure.

COMPUTER-SIMULATED SHELL SIZE AND SHAPE VARIATION IN THE CARIBBEAN LAND SNAIL GENUS CERION: A TEST OF GEOMETRICAL CONSTRAINTS

A computer graphical model of gastropod shell form is used to test a hypothesis of geometric constraint proposed to explain the disjunct distribution of shell forms observed in Cerion, a species-rich and geometrically varied genus of terrestrial gastropods. The mapping of computer-simulated forms into a morphospace of Cerion shells produces a continuum of sizes and shapes. Therefore, the absence of particular shell forms is not explained by geometric constraints. Two proposed modes of shell morphogenesis at extreme ranges in size ("dwarfs" and "giants") previously were thought to be exclusive routes to the construction of high-spired ("smokestack") forms. The present study shows that there are, in fact, multiple routes of transformation. In addition, these routes are geometrically reversible and interconnect the members of the shell-form continuum. Thus, the possible pathways followed during the course of evolution within this genus cannot be determined until an adequate phylogenetic hypothesis has been proposed.

[Effects of the Active Components of Humic Acids and Their Proportions on the Dynamics of Lead Transformation and Availability in Purple Alluvial Soil]

Humic acids (HAs) play important roles in mediating the occurring forms and activity of Lead (Pb) in soils. Simulating experiments together with chemical sequential extraction were carried out to understand the dynamics of lead transformation and availability in purple alluvial soil as influenced by humic acid (HA) and fulvic acid (FA) and their ratios (HA/FA). The main results obtained are as following:1 The distributions of Pb forms bound by Fe-Mn oxides and organic matter increased, while the proportions of exchangeable Pb and residual Pb fraction decreased after the establishment of transformation equilibrium in 60 d. 2The exchangeable-Pb and carbonate bound Pb showed highest positive contribution to the availability of Pb in the tested soil; and HA passivated soil Pb activity by decreasing the proportion of carbonate bound Pb and FA activated soil Pb by increasing the proportions of exchangeable Pb and carbonate bound Pb. The passivation or activation roles increased with increasing amount of HA or FA; A sharp increase of soil Pb availability occurred at FA dosage higher than 1% as C basis, suggesting that 1% (C) exogenous FA was the change-point for soil Pb activation;3The overall effects of HAs depended on its ratio of HA/FA at a constant addition of HAs (1% C). HAs suppressed soil Pb activity at a ratio of HA/FA ≥7/3, while they activated soil Pb activity at a ratio of HA/FA≤5/5. The transformation extent and direction of Pb in soils differed at various dosage and ratios of HA/FA, resulting in different overall effects on the Pb availability in soil.

[Forms Distribution and Ecotoxicity of Three Forms of Sulfonamides in Root-Soil Interface of Maize]

Forms distribution and ecotoxicity of sulfonamides in root-soil interface of maize were studied by chemical analysis and luminescent bacteria toxicity assay. The results indicated that the water soluble residues were the main form in rhizosperic soils, and the organic solvent extractable residues were the main form in far-rhizosperic soils. The three forms of sulfonamides showed relatively lower toxicity to luminescent bacteria with the relative inhibition rates less than 30%. The toxicity of water soluble residues was lower than that of the organic solvent extractable residues, and the bound residues showed the lowest toxicity to luminescent bacteria. The contents and relative inhibition rates of water soluble residues in rhizosperic soils were higher than those in far-rhizosperic soils, while the contents and relative inhibition rates of organic solvent extractable and bound residues in rhizosperic soils were lower than those in far-rhizosperic soils.

Recurrent Network Dynamics; a Link between Form and Motion

To discriminate visual features such as corners and contours, the brain must be sensitive to spatial correlations between multiple points in an image. Consistent with this, macaque V2 neurons respond selectively to patterns with well-defined multipoint correlations. Here, we show that a standard feedforward model (a cascade of linear–non-linear filters) does not capture this multipoint selectivity. As an alternative, we developed an artificial neural network model with two hierarchical stages of processing and locally recurrent connectivity. This model faithfully reproduced neurons’ selectivity for multipoint correlations. By probing the model, we gained novel insights into early form processing. First, the diverse selectivity for multipoint correlations and complex response dynamics of the hidden units in the model were surprisingly similar to those observed in V1 and V2. This suggests that both transient and sustained response dynamics may be a vital part of form computations. Second, the model self-organized units with speed and direction selectivity that was correlated with selectivity for multipoint correlations. In other words, the model units that detected multipoint spatial correlations also detected space-time correlations. This leads to the novel hypothesis that higher-order spatial correlations could be computed by the rapid, sequential assessment and comparison of multiple low-order correlations within the receptive field. This computation links spatial and temporal processing and leads to the testable prediction that the analysis of complex form and motion are closely intertwined in early visual cortex.

Chromosome conformation and gene expression patterns differ profoundly in human fibroblasts grown in spheroids versus monolayers

Human cells derived for in vitro cultures are conventionally grown as adherent monolayers (2D) which do not resemble natural 3 dimensional (3D) tissue architecture. We examined genome structure with chromosome conformation capture (Hi-C) and gene expression with RNA-seq in fibroblasts derived from human foreskin grown in 2D and 3D conditions. Our combined analysis of Hi-C and RNA-seq data shows a large number of differentially expressed genes between 2D and 3D cells, and these changes are localized in genomic regions that displayed structural changes. We also find a trend of expression in a subset of skin-specific genes in fibroblast cells grown in 3D that resembles those in native tissue.

Fruit form Influences Postprandial Glycemic Response in Elderly and Young Adults

OBJECTIVES

This study compared the effects of consuming different forms (bite size, puree) and two fruit types (guava, papaya) on glycemic response (GR) in elderly and young adults.

DESIGN

This study was conducted using a randomized, crossover design.

PARTICIPANTS

Nineteen healthy participants (9 elderly, 10 young adults) were recruited from the general public in Singapore.

INTERVENTION

Participants consumed glucose (reference food) on three occasions and test fruits (guava bites, guava puree, papaya bites, and papaya puree) on one occasion each.

MEASUREMENTS

Blood glucose was analyzed prior to consuming the test food, at 15, 30, 45, 60, 90 and 120 minutes after food consumption.

RESULTS

The incremental area under the blood glucose response curve (iAUC) over 120 minutes for all the treatments was significantly lower than glucose (all P < 0.001). All fruit forms and types studied were low glycemic index (GI) (guava bites: 29; papaya bites: 38; papaya puree: 42; guava puree: 47), albeit a significant difference in GI between the treatments was found (P = 0.003). Elderly exhibited significantly greater GR than young participants (P = 0.019).

CONCLUSION

Although fruit form influences GR in the elderly and young adults, all fruit types and forms studied were found to be low GI. This study indicates that fruits are a valuable source of nutrient irrespective of the form of delivery in elderly and young adults. This study was registered at www.anzctr.org.au as ACTRN12614000655640.

Thermal stability and decompositions kinetics under non-isothermal conditions of imatinib mesylate α form

The thermal decomposition and kinetic parameters of synthetized imatinib mesylate α form α form were determined by thermogravimetry (TGA/DTG) under non-isothermal conditions. The experiments were performed at a 25-940°C temperature range at five different heating rates: 2.5Kmin(-1), 5Kmin(-1), 10Kmin(-1), 15Kmin(-1) and 20Kmin(-1) per minute in a nitrogen atmosphere. Imatinib mesylate α form presents one-step mass loss during the degradation process. The thermal stability of the examined material, the melting temperature (Tonset=220.6°C) and ΔH fusion=-95.74Jg(-1) at a heating rate of 10°Cmin(-1) was established. The values of activation energies have been estimated using Kissinger, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods.

Ontogeny of head and caudal fin shape of an apex marine predator: The tiger shark (Galeocerdo cuvier)

How morphology changes with size can have profound effects on the life history and ecology of an animal. For apex predators that can impact higher level ecosystem processes, such changes may have consequences for other species. Tiger sharks (Galeocerdo cuvier) are an apex predator in tropical seas, and, as adults, are highly migratory. However, little is known about ontogenetic changes in their body form, especially in relation to two aspects of shape that influence locomotion (caudal fin) and feeding (head shape). We captured digital images of the heads and caudal fins of live tiger sharks from Southern Florida and the Bahamas ranging in body size (hence age), and quantified shape of each using elliptical Fourier analysis. This revealed changes in the shape of the head and caudal fin of tiger sharks across ontogeny. Smaller juvenile tiger sharks show an asymmetrical tail with the dorsal (upper) lobe being substantially larger than the ventral (lower) lobe, and transition to more symmetrical tail in larger adults, although the upper lobe remains relatively larger in adults. The heads of juvenile tiger sharks are more conical, which transition to relatively broader heads over ontogeny. We interpret these changes as a result of two ecological transitions. First, adult tiger sharks can undertake extensive migrations and a more symmetrical tail could be more efficient for swimming longer distances, although we did not test this possibility. Second, adult tiger sharks expand their diet to consume larger and more diverse prey with age (turtles, mammals, and elasmobranchs), which requires substantially greater bite area and force to process. In contrast, juvenile tiger sharks consume smaller prey, such as fishes, crustaceans, and invertebrates. Our data reveal significant morphological shifts in an apex predator, which could have effects for other species that tiger sharks consume and interact with.

The physiology and psychophysics of the color-form relationship: a review

The relationship between color and form has been a long standing issue in visual science. A picture of functional segregation and topographic clustering emerges from anatomical and electrophysiological studies in animals, as well as by brain imaging studies in human. However, one of the many roles of chromatic information is to support form perception, and in some cases it can do so in a way superior to achromatic (luminance) information. This occurs both at an early, contour-detection stage, as well as in late, higher stages involving spatial integration and the perception of global shapes. Pure chromatic contrast can also support several visual illusions related to form-perception. On the other hand, form seems a necessary prerequisite for the computation and assignment of color across space, and there are several respects in which the color of an object can be influenced by its form. Evidently, color and form are mutually dependent. Electrophysiological studies have revealed neurons in the visual brain able to signal contours determined by pure chromatic contrast, the spatial tuning of which is similar to that of neurons carrying luminance information. It seems that, especially at an early stage, form is processed by several, independent systems that interact with each other, each one having different tuning characteristics in color space. At later processing stages, mechanisms able to combine information coming from different sources emerge. A clear interaction between color and form is manifested by the fact that color-form contingencies can be observed in various perceptual phenomena such as adaptation aftereffects and illusions. Such an interaction suggests a possible early binding between these two attributes, something that has been verified by both electrophysiological and fMRI studies.

Visual Adaptation

Sensory systems continuously mold themselves to the widely varying contexts in which they must operate. Studies of these adaptations have played a long and central role in vision science. In part this is because the specific adaptations remain a powerful tool for dissecting vision, by exposing the mechanisms that are adapting. That is, "if it adapts, it's there." Many insights about vision have come from using adaptation in this way, as a method. A second important trend has been the realization that the processes of adaptation are themselves essential to how vision works, and thus are likely to operate at all levels. That is, "if it's there, it adapts." This has focused interest on the mechanisms of adaptation as the target rather than the probe. Together both approaches have led to an emerging insight of adaptation as a fundamental and ubiquitous coding strategy impacting all aspects of how we see.

Crystals: animal, vegetable or mineral?

The morphologies of biological materials, from body shapes to membranes within cells, are typically curvaceous and flexible, in contrast to the angular, facetted shapes of inorganic matter. An alternative dichotomy has it that biomolecules typically assemble into aperiodic structures in vivo, in contrast to inorganic crystals. This paper explores the evolution of our understanding of structures across the spectrum of materials, from living to inanimate, driven by those naive beliefs, with particular focus on the development of crystallography in materials science and biology. The idea that there is a clear distinction between these two classes of matter has waxed and waned in popularity through past centuries. Our current understanding, driven largely by detailed exploration of biomolecular structures at the sub-cellular level initiated by Bernal and Astbury in the 1930s, and more recent explorations of sterile soft matter, makes it clear that this is a false dichotomy. For example, liquid crystals and other soft materials are common to both living and inanimate materials. The older picture of disjoint universes of forms is better understood as a continuum of forms, with significant overlap and common features unifying biological and inorganic matter. In addition to the philosophical relevance of this perspective, there are important ramifications for science. For example, the debates surrounding extra-terrestrial life, the oldest terrestrial fossils and consequent dating of the emergence of life on the Earth rests to some degree on prejudices inferred from the supposed dichotomy between life-forms and the rest.

Distributed processing of color and form in the visual cortex

To what extent does the visual system process color and form separately? Proponents of the segregation view claim that distinct regions of the cortex are dedicated to each of these two dimensions separately. However, evidence is accumulating that color and form processing may, at least to some extent, be intertwined in the brain. In this perspective, we review psychophysical and neurophysiological studies on color and form perception and evaluate their results in light of recent developments in population coding.

Detecting shape change: characterizing the interaction between texture-defined and contour-defined borders

The human visual system's extreme sensitivity to subtle changes in shape can often be attributed to global pooling of local information. This has been shown for shapes described by paths of contiguous elements, but it was unknown whether this global pooling translated to shapes defined by texture-segmentation borders. Also, previous research suggests that texture and luminance cues-to-shape are integrated by the visual system for shape detection but it has not been established whether they combined for shape discrimination. Controlled shapes defined either by an explicit path of Gabors, texture-segmentation borders, or both of these cues were used. Results show that all stimuli used were globally processed. Thresholds for shapes defined by both cues matched predictions based on an independent-cue vector sum of individual thresholds. Thus, while local elements are integrated around the contour and are processed by global shape-detection mechanisms, integration did not occur across different shape-cues.

The IAT shows no evidence for Kandinsky's color-shape associations

In the early twentieth century, the Bauhaus revolutionized art and design by using simple colors and forms. Wassily Kandinsky was especially interested in the relationship of these two visual attributes and postulated a fundamental correspondence between color and form: yellow triangle, red square and blue circle. Subsequent empirical studies used preference judgments to test Kandinsky's original color-form combinations, usually yielding inconsistent results. We have set out to test the validity of these postulated associations by using the Implicit Association Test. Participants pressed one of two buttons on each trial. On some trials they classified shapes (e.g., circle or triangle). On interleaved trials they classified colors (e.g., blue or yellow). Response times should theoretically be faster when the button mapping follows Kandinsky's associations: For example, when the left key is used to report blue or circle and the right is used for yellow and triangle, than when the response mapping is the opposite of this (blue or triangle, yellow or circle). Our findings suggest that there is no implicit association between the original color-form combinations. Of the three combinations we tested, there was only a marginal effect in one case. It can be concluded that the IAT does not support Kandinsky's postulated color-form associations, and that these are probably not a universal property of the visual system.

Long-lasting visual integration of form, motion, and color as revealed by visual masking

When two similar visual stimuli are presented in rapid succession at the same location, they fuse. For example, a red and a green disk are perceived as one single yellow disk. Likewise, verniers with opposite offset directions are perceived as one vernier with an almost aligned vernier offset. In fusion, observers have no conscious access to the individual stimuli. Using transcranial magnetic stimulation (TMS), it has been shown that feature fusion for verniers can be modulated for about 400 ms in that either the first or the second vernier dominates the percept, depending on TMS onset. Here, we use light masks to modulate feature fusion for verniers, motion, and color. Our results are similar to the TMS experiment and show that individual visual features are stored for a substantial amount of time before they are integrated.

The Importance of Form in Skinner's Analysis of Verbal Behavior and a Further Step

A series of quotes from B. F. Skinner illustrates the importance of form in his analysis of verbal behavior. In that analysis, form plays an important part in contingency control. Form and function complement each other. Function, the array of variables that control a verbal utterance, dictates the meaning of a specified form; form, as stipulated by a verbal community, indicates that meaning. The mediational actions that shape verbal utterances do not necessarily encounter their controlling variables. These are inferred from the form of the verbal utterance. Form carries the burden of implied meaning and underscores the importance of the verbal community in the expression of all the forms of language. Skinner's analysis of verbal behavior and the importance of form within that analysis provides the foundation by which to investigate language. But a further step needs to be undertaken to examine and to explain the abstractions of language as an outcome of action at an aggregate level.

Detecting shapes in noise: tuning characteristics of global shape mechanisms

The proportion of signal elements embedded in noise needed to detect a signal is a standard tool for investigating motion perception. This paradigm was applied to the shape domain to determine how local information is pooled into a global percept. Stimulus arrays consisted of oriented Gabor elements that sampled the circumference of concentric radial frequency (RF) patterns. Individual Gabors were oriented tangentially to the shape (signal) or randomly (noise). In different conditions, signal elements were located randomly within the entire array or constrained to fall along one of the concentric contours. Coherence thresholds were measured for RF patterns with various frequencies (number of corners) and amplitudes (“sharpness” of corners). Coherence thresholds (about 10% = 15 elements) were lowest for circular shapes. Manipulating shape frequency or amplitude showed a range where thresholds remain unaffected (frequency ≤ RF4; amplitude ≤ 0.05). Increasing either parameter caused thresholds to rise. Compared to circles, thresholds increased by approximately four times for RF13 and five times for amplitudes of 0.3. Confining the signals to individual contours significantly reduced the number of elements needed to reach threshold (between 4 and 6), independent of the total number of elements on the contour or contour shape. Finally, adding external noise to the orientation of the elements had a greater effect on detection thresholds than adding noise to their position. These results provide evidence for a series of highly sensitive, shape-specific analysers which sum information globally but only from within specific annuli. These global mechanisms are tuned to position and orientation of local elements from which they pool information. The overall performance for arrays of elements can be explained by the sensitivity of multiple, independent concentric shape detectors rather than a single detector integrating information widely across space (e.g. Glass pattern detector).

MEMORY FOR POETRY: MORE THAN MEANING?

The assumption has become that memory for words' sound patterns, or form, is rapidly lost in comparison to content. Memory for form is also assumed to be verbatim rather than schematic. Oral story-telling traditions suggest otherwise. The present experiment investigated if form can be remembered schematically in spoken poetry, a context in which form is important. We also explored if sleep could help preserve memory for form. We tested whether alliterative sound patterns could cue memory for poetry lines both immediately and after a delay of 12 hours that did or did not include sleep. Twelve alliterative poetry lines were modified into same alliteration, different alliteration, and no alliteration paraphrases. We predicted that memory for original poetry lines would be less accurate after 12 hours, same alliteration paraphrases would be falsely recognized as originals more often after 12 hours, and that the no-sleep group would make more errors. Different alliteration and no alliteration paraphrases were not expected to share this effect due to schematically different sound patterns. Our data support these hypotheses and provide evidence that memory for form is schematic in nature, retained in contexts in which form matters, and that sleep may help preserve memory for sound patterns.

Binocular rivalry produced by temporal frequency differences

When the eyes view images that are sufficiently different to prevent binocular fusion, binocular rivalry occurs and the images are seen sequentially in a stochastic alternation. Here we examine whether temporal frequency differences will trigger binocular rivalry by presenting two dynamic random-pixel arrays that are spatially matched but which modulate temporally at two different rates. We found that binocular rivalry between the two temporal frequencies did indeed occur, provided the frequencies were sufficiently different. Differences greater than two octaves (i.e., a factor of four) produced robust rivalry with clear-cut alternations similar to those experienced with spatial rivalry and with similar alternation rates. This finding indicates that temporal information can produce binocular rivalry in the absence of spatial conflict and is discussed in terms of rivalry requiring conflict between temporal channels.

Relationship between neural response and adaptation selectivity to form and color: an ERP study

Adaptation is widely used as a tool for studying selectivity to visual features. In these studies it is usually assumed that the loci of feature selective neural responses and adaptation coincide. We used an adaptation paradigm to investigate the relationship between response and adaptation selectivity in event-related potentials (ERPs). ERPs were evoked by the presentation of colored Glass patterns in a form discrimination task. Response selectivities to form and, to some extent, color of the patterns were reflected in the C1 and N1 ERP components. Adaptation selectivity to color was reflected in N1 and was followed by a late (300–500 ms after stimulus onset) effect of form adaptation. Thus for form, response and adaptation selectivity were manifested in non-overlapping intervals. These results indicate that adaptation and response selectivity can be associated with different processes. Therefore, inferring selectivity from an adaptation paradigm requires analysis of both adaptation and neural response data.

Top-down modulations in the visual form pathway revealed with dynamic causal modeling

Perception entails interactions between activated brain visual areas and the records of previous sensations, allowing for processes like figure-ground segregation and object recognition. The aim of this study was to characterize top-down effects that originate in the visual cortex and that are involved in the generation and perception of form. We performed a functional magnetic resonance imaging experiment, where subjects viewed 3 groups of stimuli comprising oriented lines with different levels of recognizable high-order structure (none, collinearity, and meaning). Our results showed that recognizable stimuli cause larger activations in anterior visual and frontal areas. In contrast, when stimuli are random or unrecognizable, activations are greater in posterior visual areas, following a hierarchical organization where areas V1/V2 were less active with "collinearity" and the middle occipital cortex was less active with "meaning." An effective connectivity analysis using dynamic causal modeling showed that high-order visual form engages higher visual areas that generate top-down signals, from multiple levels of the visual hierarchy. These results are consistent with a model in which if a stimulus has recognizable attributes, such as collinearity and meaning, the areas specialized for processing these attributes send top-down messages to the lower levels to facilitate more efficient encoding of visual form.

Ethylene, free radicals and the transition between stable states in plant morphology

Treatment with hydrogen peroxide has notable effects in the morphology of the root apex in Arabidopsis seedlings. The result was described as consisting in two aspects: first, a reduction in curvature values in the root profile. Second, alterations in size and shape of the cells in the root cap. Cells of the root cap were smaller and had higher circularity index (Fig. 1). The results of peroxide treatment were similar to alterations in the root apex of ethylene insensitive mutants and wild-type seedlings treated with ethylene inhibitors. This brings new evidence in favour of the association between ethylene and hydrogen peroxide signalling that was recently demonstrated in stomatal cells. Notable changes in morphology under peroxide treatment were previously reported in other biological systems (Fig. 2). In the following paragraphs we make emphasis on the need of an accurate analysis of morphology. This aspect has not received the attention required in biology, a discipline dominated by functional analysis. We suggest that the observed morphological characteristics in the root apex treated with peroxide may be the manifestation of global processes of adaptation in the organism. Alternative forms of roots grown in water or in peroxide are stable situations representing different global configurations that may have other (genomic, physiological) traits associated. Each form represents a different mode of adaptation to environmental change. The accurate description of morphology in organisms, with particular emphasis in model systems, and their variations under stress, is needed to identify and understand the basis of genomic organization and plasticity.

Visual perception and its impairment in schizophrenia

Much work in the cognitive neuroscience of schizophrenia has focused on attention, memory, and executive functioning. To date, less work has focused on perceptual processing. However, perceptual functions are frequently disrupted in schizophrenia, and thus this domain has been included in the CNTRICS (Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia) project. In this article, we describe the basic science presentation and the breakout group discussion on the topic of perception from the first CNTRICS meeting, held in Bethesda, Maryland on February 26 and 27, 2007. The importance of perceptual dysfunction in schizophrenia, the nature of perceptual abnormalities in this disorder, and the critical need to develop perceptual tests appropriate for future clinical trials were discussed. Although deficits are also seen in auditory, olfactory, and somatosensory processing in schizophrenia, the first CNTRICS meeting focused on visual processing deficits. Key concepts of gain control and integration in visual perception were introduced. Definitions and examples of these concepts are provided in this article. Use of visual gain control and integration fit a number of the criteria suggested by the CNTRICS committee, provide fundamental constructs for understanding the visual system in schizophrenia, and are inclusive of both lower-level and higher-level perceptual deficits.

Sorghum roots are inefficient in uptake of EDTA-chelated lead

BACKGROUND AND AIMS

Ethylene diamine tetraacetic acid (EDTA)-assisted phytoremediation has been developed to clean up lead (Pb)-contaminated soil; however, the mechanism responsible for the uptake of EDTA-Pb complex is not well understood. In this study, the accumulation process of Pb from EDTA-Pb is characterized in comparison to ionic Pb [Pb(NO(3))(2)] in sorghum (Sorghum bicolor).

METHODS

Sorghum seedlings were exposed to a 0.5 mM CaCl(2) (pH 5.0) solution containing 0, 1 mM Pb(NO(3))(2) or EDTA-Pb complexes at a molar ratio of 1:0.5, 1:1, 1:2 and 1:4 (Pb:EDTA). The root elongation of sorghum at different ratios of Pb:EDTA was measured. Xylem sap was collected after the stem was severed at different times. The concentration of Pb in the shoots and roots were determined by an atomic absorption spectrometer. In addition, the roots were stained with Fluostain I for observation of the root structure.

KEY RESULTS

Lead accumulation in the shoots of the plants exposed to EDTA-Pb at 1:1 ratio was only one-fifth of that exposed to ionic Pb at the same concentration. Lead accumulation decreased when transpiration was suppressed. The concentration of Pb in the xylem sap from the EDTA-Pb-treated plants was about 1/25,000 of that in the external solution. Root elongation was severely inhibited by ionic Pb, but not by EDTA-Pb at a 1:1 ratio. Root staining showed that a physiological barrier was damaged in the roots exposed to ionic Pb, but not in the roots exposed to EDTA-Pb.

CONCLUSIONS

All these results suggest that sorghum roots are inefficient in uptake of EDTA-chelated Pb and that enhanced Pb accumulation from ionic Pb was attributed to the damaged structure of the roots.

Structure of receptive fields in area 3b of primary somatosensory cortex in the alert monkey

We investigated the two-dimensional structure of area 3b neuronal receptive fields (RFs) in three alert monkeys. Three hundred thirty neurons with RFs on the distal fingerpads were studied with scanned, random dot stimuli. Each neuron was stimulated continuously for 14 min, yielding 20,000 response data points. Excitatory and inhibitory components of each RF were determined with a modified linear regression algorithm. Analyses assessing goodness-of-fit, repeatability, and generality of the RFs were developed. Two hundred forty-seven neurons yielded highly repeatable RF estimates, and most RFs accounted for a large fraction of the explainable response of each neuron. Although the area 3b RF structures appeared to be continuously distributed, certain structural generalities were apparent. Most RFs (94%) contained a single, central region of excitation and one or more regions of inhibition located on one, two, three, or all four sides of the excitatory center. The shape, area, and strength of excitatory and inhibitory RF regions ranged widely. Half the RFs contained almost evenly balanced excitation and inhibition. The findings indicate that area 3b neurons act as local spatiotemporal filters that are maximally excited by the presence of particular stimulus features. We believe that form and texture perception are based on high-level representations and that area 3b is an intermediate stage in the processes leading to these representations. Two possibilities are considered: (1) that these high-level representations are basically somatotopic and that area 3b neurons amplify some features and suppress others, or (2) that these representations are highly transformed and that area 3b effects a step in the transformation.

Single-dose pharmacokinetic and pharmacodynamic comparison of polymer-matrix (Slow Trasicor) and Oros dosage forms of oxprenolol in healthy volunteers

Oxprenolol was administered in single doses by mouth to healthy volunteers either in a polymer-matrix slow-release formulation (Slow Trasicor) or in osmotic drug-delivery systems (oxprenolol Oros). Plasma oxprenolol concentrations and heart rates after exercise were measured. Plasma concentrations of the drug were maximal at 3 h but negligible at 24 h after administration of Slow Trasicor. Following ingestion of the Oros systems measurable concentrations were maintained throughout 24 h. Significant reduction of exercise-induced tachycardia persisted for 24 h after administration of oxprenolol Oros. With Slow Trasicor heart rate responses had returned to baseline values by this time. The osmotic drug-delivery systems appear to sustain significant beta-adrenoceptor blockade for 24 h after a single oral dose.