High-level Areas Research Articles

On the microstructure evolution of a nuclear-use steel after heavy ion irradiation

A nuclear-use ferritic-martensitic steel was irradiated by 196 MeV Kr ions. Both the low damage level area and the high damage level area were investigated by a transmission electron microscope (TEM), to reveal the irradiated microstructural features. In low damage level area ranging from surface to 6 μm depth, there were a few dislocation loops and black dots induced by Kr irradiation. The type of dislocation loops could be primarily ao<100> or ao/2<100> type. In addition, it was found that the sink effect of grain boundaries and stability of small precipitates were evident.

A functional theory of bistable perception based on dynamical circular inference.

When we face ambiguous images, the brain cannot commit to a single percept; instead, it switches between mutually exclusive interpretations every few seconds, a phenomenon known as bistable perception. While neuromechanistic models, e.g., adapting neural populations with lateral inhibition, may account for the dynamics of bistability, a larger question remains unresolved: how this phenomenon informs us on generic perceptual processes in less artificial contexts. Here, we propose that bistable perception is due to our prior beliefs being reverberated in the cortical hierarchy and corrupting the sensory evidence, a phenomenon known as "circular inference". Such circularity could occur in a hierarchical brain where sensory responses trigger activity in higher-level areas but are also modulated by feedback projections from these same areas. We show that in the face of ambiguous sensory stimuli, circular inference can change the dynamics of the perceptual system and turn what should be an integrator of inputs into a bistable attractor switching between two highly trusted interpretations. The model captures various aspects of bistability, including Levelt's laws and the stabilizing effects of intermittent presentation of the stimulus. Since it is related to the generic perceptual inference and belief updating mechanisms, this approach can be used to predict the tendency of individuals to form aberrant beliefs from their bistable perception behavior. Overall, we suggest that feedforward/feedback information loops in hierarchical neural networks, a phenomenon that could lead to psychotic symptoms when overly strong, could also underlie perception in nonclinical populations.

Distribution of 137Cs and 60Co in plough layer of farmland: Evidenced from a lysimeter experiment using undisturbed soil columns

ABSTRACT Radionuclide fallout during nuclear accidents on the land may impair the atmosphere, contaminate farmland soils and crops, and can even reach the groundwater. Previous research focused on the field distribution of deposited radionuclides in farmland soils, but details of the amounts of radionuclides in the plough layer and the changes in their proportional distribution in the soil profile with time are still inadequate. In this study, a lysimeter experiment was conducted to determine the vertical migration of 137Cs and 60Co in brown and aeolian sandy soils, collected from the farmlands adjoining Shidaowan Nuclear Power Plant (NPP) in eastern China, and to identify the factors influencing their migration depths in soil. At the end of the experiment (800 d), > 96% of added 137Cs and 60Co were retained in the top 0–20 cm soil layer of both soils; very little 137Cs or 60Co initially migrated to 20–30 cm, but their amounts at this depth increased with time. The migration depth of 137Cs was greater in the aeolian sandy soil than in the brown soil during 0–577 d, but at the end of the experiment, 137Cs migrated to the same depth (25 cm) in both soils. Three phases on the vertical migration rate (v) of 60Co in the aeolian sandy soil can be identified: an initial rapid movement (0–355 d, v = 219 ± 17 mm year–1), followed by a steady movement (355–577 d, v = 150 ± 24 mm year–1) and a very slow movement (577–800 d, v = 107 ± 7 mm year–1). In contrast, its migration rate in the brown soil (v = 133 ± 17 mm year–1) was steady throughout the 800-d experimental period. The migration of both 137Cs and 60Co in the two soils appears to be regulated by soil clay and silt fractions that provide most of the soil surface area, soil organic carbon (SOC), and soil pH, which were manifested by the solid-liquid distribution coefficient of 137Cs and 60Co. The results of this study suggest that most 137Cs and 60Co remained within the top layer (0–20 cm depth) of farmland soils following a simulated NPP accident, and little reached the subsurface (20–30 cm depth). Fixation of radionuclides onto clay minerals may limit their migration in soil, but some could be laterally distributed by soil erosion and taken up by crops, and migrate into groundwater in a high water table level area after several decades. Remediation measures, therefore, should focus on reducing their impact on the farmland soils, crops, and water.

Analysis of Spatial Scale Effect on Urban Resilience: A Case Study of Shenyang, China

Based on urban physical space and theory of landscape ecology, a triune assessment framework —‘size-density-morphology’—was constructed in order to analyze the spatial pattern and the scale effect of urban resilience in Shenyang of China in 2015, and to explore the main impact factors of landscape under different spatial scale backgrounds. The results show that: 1) Urban resilience is an optimal combination of the resilience of size, density, and morphology. The urban resilience of Shenyang displays scale effect; the overall resilience level increases with the increase in scale, while the spatial difference and spatial similarity tend to decrease resilience. 2) As 2 km, 1 km and 2 km are scale inflection points of average value curves for size resilience, density resilience and morphology resilience, respectively in an urban setting; the optimal scale unit of comprehensive resilience is 1 km. Choosing 1 km–2 km as the basic spatial scale better depicts overall pattern and detailed characteristics of resilience in Shenyang. The spatial amplitudes of 0.5 km and 1 km are sensitive points for spatial autocorrelation of morphology and density resilience, size, and comprehensive resilience to scale effect. 3) The major landscape factors of urban size and morphology resilience transform with scale expansion. Aggregation index (AI) has a significant impact on urban resilience at different scales; its influence increases significantly with the increase in scale. 4) The high-level area of comprehensive resilience in Shenyang is the eastern ecological corridor area, while the low value area is the peripheral extension area of the city. To promote the overall level of resilience in Shenyang, this paper argues that the construction of ecological infrastructure should be strengthened in the peripheral extension area in a balanced manner. In the city center, population and building density should be controlled; the intensity of human activities should be reduced; impetus should be placed on landscape heterogeneity; and the homogeneous expansion of the area of construction should be prevented. In the eastern ecological corridors, the exploitation of ecosystem lands should be strictly controlled, and the integrity of the green landscape patches should be maintained.

Odor-Induced Saltiness Enhancement: Insights Into The Brain Chronometry Of Flavor Perception

Flavor perception results from the integration of at least odor and taste. Evidence for such integration is that odors can have taste properties (odor-induced taste). Most brain areas involved in flavor perception are high-level areas; however, primary gustatory and olfactory areas also show activations in response to a combination of odor and taste. While the regions involved in flavor perception are now quite well identified, the network's organization is not yet understood. Using a close to real salty soup model with electroencephalography brain recording, we evaluated whether odor-induced saltiness enhancement would result in differences of amplitude and/or latency in late cognitive P3 peak mostly and/or in P1 early sensory peak. Three target solutions were created from the same base of green-pea soup: i) with a “usual” salt concentration (PPS2), ii) with “reduced” salt (PPS1: −50%), and iii) with reduced salt and a “beef stock” odor (PPS1B). Sensory data showed that the beef odor produced saltiness enhancement in PPS1B in comparison to PPS1. As the main EEG result, the late cognitive P3 peak was delayed by 25 ms in the odor-added solution PPS1B compared to PPS1. The odor alone did not explain this peak amplitude and higher latency in the P3 peak. These results support the classical view that high-level integratory areas process odor–taste interactions with potential top-down effects on primary sensory regions.

Cross-fixation interactions of orientations suggest that orientation decoding occurs in a high-level area of visual working memory

Cross-fixation interactions of orientations suggest that orientation decoding occurs in a high-level area of visual working memory

Aspects of cortical area responsibilities while learning a visually cued spatiotemporal motor task.

Aspects of cortical area responsibilities while learning a visually cued spatiotemporal motor task.

Biased Neural Representation of Feature-Based Attention in the Human Frontoparietal Network.

Selective attention is a core cognitive function for efficient processing of information. Although it is well known that attention can modulate neural responses in many brain areas, the computational principles underlying attentional modulation remain unclear. Contrary to the prevailing view of a high-dimensional, distributed neural representation, here we show a surprisingly simple, biased neural representation for feature-based attention in a large dataset including five human fMRI studies. We found that when human participants (both sexes) selected one feature from a compound stimulus, voxels in many cortical areas responded consistently higher to one attended feature over the other. This univariate bias was consistent across brain areas within individual subjects. Importantly, this univariate bias showed a progressively stronger magnitude along the cortical hierarchy. In frontoparietal areas, the bias was strongest and contributed largely to pattern-based decoding, whereas early visual areas lacked such a bias. These findings suggest a gradual transition from a more analog to a more abstract representation of attentional priority along the cortical hierarchy. Biased neural responses in high-level areas likely reflect a low-dimensional neural code that can facilitate a robust representation and simple readout of cognitive variables.SIGNIFICANCE STATEMENT It is typically assumed that cognitive variables are represented by distributed population activities. Although this view is rooted in decades of work in the sensory system, it has not been rigorously tested at different levels of cortical hierarchy. Here we show a novel, low-dimensional coding scheme that dominated the representation of feature-based attention in frontoparietal areas. The simplicity of such a biased code may confer a robust representation of cognitive variables, such as attentional selection, working memory, and decision-making.

Prevalence of dental caries (DMFT) in Iraqi children and adolescent living in areas with low and high level of natural fluoride

The purpose of the study was to determine the prevalence of dental caries in a group of school children lived in area with high and low natural fluoride contained drinking water in Ninevah governorate. The study is conducted among (1724) schools students aged 11-16 years from randomly selected schools (primary and intermediate) in two provinces in Ninevah governorate. Eight hundred and thirteen students who had lived since birth in high natural fluoride level area (Sinjar province)(2.05-222 ppm) and (911) students lived continuously from birth in low natural fluoride level area in their drinking water (Talkaif province)(0.11-0.19 ppm). WHO methodology (1997) has been used to assess the dental caries status and using DMFT index for permanent teeth. The results show that in Sinjar province the mean DMFT for total samples were (1.67) and (36.2%) are caries free with no sex difference. while there is a significant age differences. On the other hand, in Talkaif province the results reveal higher DMFT (3.7) and lower percent of caries free (19.1%), The mean DMFT reported twice in Talkaif province than Sinjar province with highly significant differences between them. The percentage of reduction of dental caries has been found to be (54.3%) in Sinjar province compare to Talkaif province.

Neural dynamics of perceptual inference and its reversal during imagery.

After the presentation of a visual stimulus, neural processing cascades from low-level sensory areas to increasingly abstract representations in higher-level areas. It is often hypothesised that a reversal in neural processing underlies the generation of mental images as abstract representations are used to construct sensory representations in the absence of sensory input. According to predictive processing theories, such reversed processing also plays a central role in later stages of perception. Direct experimental evidence of reversals in neural information flow has been missing. Here, we used a combination of machine learning and magnetoencephalography to characterise neural dynamics in humans. We provide direct evidence for a reversal of the perceptual feed-forward cascade during imagery and show that, during perception, such reversals alternate with feed-forward processing in an 11 Hz oscillatory pattern. Together, these results show how common feedback processes support both veridical perception and mental imagery.

Specialized Lead Design of Leadframe Packages for Improved Mold Adhesion

This paper presents an advanced design of Quad-Flat No-leads (QFN) and Quad-Flat Package (QFP) leadframe to mitigate the propagation of delamination between high stress level areas particularly the mold-to-leads interface. The integration of through-hole mechanism on leadframe provides mechanical anchoring of mold material to the lead junction interface and/or vice versa. To produce interlocking, the through-hole design will be penetrated by the epoxy mold compound during conventional molding process affixing each individual lead to the encapsulation material. On the other hand, the package design is materialized through repeated cycle of chemical etching and masking process during leadframe manufacturing, the mechanical anchoring can be implemented on the conventional design of carriers. This approach, considering the design and assembly method of the new leadframe design, is a cost-effective alternative in improving the interfaces of key material such as mold and leadframe.

Novel quantum‐dot cellular automata implementation of flip‐flop and phase‐frequency detector based on nand‐nor‐inverter gates

SummaryCMOS technology faces fundamental challenges such as frequency and power consumption due to the impossibility of further reducing dimensions. For these reasons, researchers have been thinking replacement of this technology with other technologies such as quantum‐dot cellular automata (QCA) technology. Many studies have been done to design digital circuits using QCA technology. Phase‐frequency detector (PFD) is one of the main blocks in electrical and communication circuits. In this paper, a novel structure for PFDs in QCA technology is proposed. In the proposed design, the novel D flip‐flop (D‐FF) with reset ability is used. The D‐FF is designed by the proposed D latch which is based on nand‐nor‐inverter (NNI) and an inverter gate. This proposed D latch has 22 cells and 0.5 clock cycle latency and 0.018‐μm2 area. The inverter gate of the D‐FF has output signal with high polarization level and lower area than previous inverters, and the NNI gate of the D‐FF is a universal gate. The proposed PFD has 141 cells, 0.17‐μm2 occupied area, and two clock cycle latency that is smaller compared with PFD and is based on common inverter and majority gates.

Geochemical, Mineralogical and Petrological Characteristics of Lateritic Bauxite Deposits formed on Deccan Trap Basalt with Reference to High-level and Coastal (low level) Deposits of Maharashtra

Abstract Lateritic bauxite are the products of intense subareal weathering of rocks. It is characterised by a particular enrichment of aluminium-hydroxide minerals such as gibbsite, boehmite and diaspore. Based on geological occurrences, bauxite is classified as lateritic, karstic, tikhvin type and about 86% deposits of the world are lateritic bauxite deposits. They typically are in stable areas of plateaux, where they had sufficient geological time to form and were protected from erosion. India is endowed about 3896 million tons of bauxite resources and Maharashtra state constitutes about 5 % of the total assets. The medium to high grade lateritic bauxite occurrences are located in western Maharashtra which spread up in two distinct belts, viz. high level and low-level coastal areas. The coastal bauxite deposits in Raigad, Ratnagiri and Sindhudurg districts are located at altitude varying between 50 to 350 m above mean sea level (msl), while high level bauxite deposits of Kolhapur, Satara and Sangli districts occur on the plateaus with an elevation 900 to 1300 m above msl. Most of the laterite of the western Maharashtra overlies the Deccan Trap basalt, except in some part of coastal areas, it either caps the Kaladgi sandstone or overlie the Dharwar pebble beds. The lateritic bauxite deposits of the western Maharashtra have been studied with reference to its geology, chemico-mineralogy and petrological characteristics. Field studies indicate the following successive stages developed during in-situ weathering: Deccan trap basalt (parent rock) → weathered basalt → saprolite/lithomargic clay → bauxite → duricrust (ferruginous, aluminous laterites). The geological, physical and chemico-mineralogical characteristics of the bauxite and laterite located in two belts is distinguished from one another. For the present study, two bauxite deposits namely Ringewadi and Velas located in Kolhapur (high-level) and Raigad (coastal) district of western Maharashtra respectively have been selected. The representative samples of bauxite, laterite, saprolite, parent rock have been collected. In present paper, comparative study has been done and the geological, geomorphological, geochemical, mineralogical, petrographic and physical characteristics of low level (coastal) and high-level lateritic bauxite deposits are highlighted.

Evaluation of the influence of chronic low-dose radiation on DNA repair gene polymorphisms [XRCC1, XRCC3, PRKDC (XRCC7), LIG1, NEIL1] in individuals from normal and high level natural radiation areas of Kerala Coast

Background: Single Nucleotide Polymorphisms (SNPs) at DNA repair genes are considered as potential biomarkers of radio-sensitivity. The coastal belt of Kerala in south west India has a patchy distribution of monazite in its beach sand that contains Th-232 and its decay products. Thus, radiation levels in this area vary from <1.0mGy to 45.0mGy/year. The areas with external gamma radiation dose >1.5mGy/year are considered as High-Level Natural Radiation Areas (HLNRA) and ≤ 1.5mGy/year are Normal Level Natural Radiation Area (NLNRA).Objective: In the present study, an attempt was made to evaluate the influence of chronic low dose radiation exposure on DNA repair gene polymorphisms in NLNRA and HLNRA population of Kerala coast.Materials and methods: Genomic DNA was isolated from venous blood samples of 246 random, healthy individuals (NLNRA, N = 104; HLNRA, N = 142) and genotyping of five SNPs such as X-ray repair cross complementing 1(XRCC1 Arg399Gln), X-ray repair cross complementing 3 (XRCC3 Thr241Met], Protein kinase, DNA-activated, catalytic subunit (PRKDC) (X-ray repair cross-complementing group 7, XRCC7 G/T), nei like DNA glycosylase 1 (NEIL1 G/T) and DNA ligase 1 (LIG1 A/C) was carried out using PCR based restriction fragment length polymorphism (PCR-RFLP) followed by silver staining.Results: Our results showed no significant difference in genotype frequencies in HLNRA vs NLNRA at three of the five SNPs studied i.e. XRCC1 Arg399Gln (χ2(2) = 5.85, p = .054), XRCC3 Thr241Met (χ2(1) = 0.71, p = .339), PRKDC (XRCC7 G/T) (χ2(2) = 3.72, p = .156), whereas significant difference was observed at NEIL1 G/T (χ2(2) =8.71, p = .013) and LIG1 A/C (χ2(2) = 7.66, p = .022). The odds of heterozygote to homozygote genotypes in HLNRA relative to NLNRA at XRCC1 Arg399Gln (OR = 1.96, 95% CI: 1.13–3.40), XRCC3 Thr241Met (OR = 0.73, 95% CI: 0.41–1.31), PRKDC (XRCC7 G/T), (OR = 0.81; 95% CI: 0.48–1.38), NEIL1 G/T (OR = 0.54; 95% CI: 0.31–0.96) and LIG1 A/C (OR = 1.62; 95% CI: 0.97–2.69) was also not significantly different in HLNRA vs NLNRA, except at XRCC1 and NEIL1.Conclusion: The genotype frequencies at three of these SNPs i.e. XRCC1 Arg399Gln, XRCC3 Thr241Met and PRKDC (XRCC7 G/T) were similar, whereas NEIL1 G/T and LIG1 A/C showed significant difference between HLNRA and NLNRA population. However, further research using more number of SNPs in a larger cohort is required in this study area.

Forms of prediction in the nervoussystem.

The idea that predictions shape how we perceive and comprehend the world has become increasingly influential in the field of systems neuroscience. It also forms an important framework for understanding neuropsychiatric disorders, which are proposed to be the result of disturbances in the mechanisms through which prior information influences perception and belief, leading to the production of suboptimal models of the world. There is a widespread tendency to conceptualize the influence of predictions exclusively in terms of 'top-down' processes, whereby predictions generated in higher-level areas exert their influence on lower-level areas within an information processing hierarchy. However, this excludes from consideration the predictive information embedded in the 'bottom-up' stream of information processing. We describe evidence for the importance of this distinction and argue that it is critical for the development of the predictive processing framework and, ultimately, for an understanding of the perturbations that drive the emergence of neuropsychiatric symptoms and experiences.

Urbanicity and autism of children in China

ObjectivesIncreased risk of autism with the increment of urbanization has been documented in developed countries. However, very few studies in developing countries focused on this topic. By using Chinese nationally representative large dataset, we investigated the association between urbanicity and autism among children aged 0–17 years in China. Also, we analyzed whether there existed a sexually dimorphic effect on this association. MethodsData from the Second National Sample Survey on Disability (SNSSD) was used in this study, and 616,940 children was selected for analysis. Autism was measured by experienced psychiatrists according to The International Statistical Classification of Diseases and Related Health Problems 10th Revision Symptom Checklist for Mental Disorders. Logistic regression models allowing for multiple demographic and socioeconomic covariates were used to evaluate the association between the level of urbanization and autism in children. ResultsCompared with children in low level of urbanization areas, those in high urbanization level areas was 2.12 (95%CI: 1.28, 3.49) times more likely to develop autism, and 1.85 (95%CI: 1.21, 2.84) times for those in moderate level of urbanization areas. Stratified analyses found that all observed associations were only in male children, not in female children. ConclusionsOur findings suggested that higher level of urbanicity was associated with higher risk of autism in children. This association was only present in male children, not in female children.

Cross-Talk of Low-Level Sensory and High-Level Cognitive Processing: Development, Mechanisms, and Relevance for Cross-Modal Abilities of the Brain.

The emergence of cross-modal learning capabilities requires the interaction of neural areas accounting for sensory and cognitive processing. Convergence of multiple sensory inputs is observed in low-level sensory cortices including primary somatosensory (S1), visual (V1), and auditory cortex (A1), as well as in high-level areas such as prefrontal cortex (PFC). Evidence shows that local neural activity and functional connectivity between sensory cortices participate in cross-modal processing. However, little is known about the functional interplay between neural areas underlying sensory and cognitive processing required for cross-modal learning capabilities across life. Here we review our current knowledge on the interdependence of low- and high-level cortices for the emergence of cross-modal processing in rodents. First, we summarize the mechanisms underlying the integration of multiple senses and how cross-modal processing in primary sensory cortices might be modified by top-down modulation of the PFC. Second, we examine the critical factors and developmental mechanisms that account for the interaction between neuronal networks involved in sensory and cognitive processing. Finally, we discuss the applicability and relevance of cross-modal processing for brain-inspired intelligent robotics. An in-depth understanding of the factors and mechanisms controlling cross-modal processing might inspire the refinement of robotic systems by better mimicking neural computations.

Beach litter composition and distribution on the Atlantic coast of Cádiz (SW Spain)

A total amount of 16,123 beach litter items, appertaining to 120 litter groups, was identified at 40 bathing areas along the coast of Cádiz, Spain. Selected areas covered remote (5), rural (11), village (13) and urban (11) sites with different morphodynamic states. The observer recorded litter data along 100 m (longshore) coastal sectors, cross-shore extended from the shoreline up to the landward limit of the beach. Litter was quantified at the low tide water level (where 2.1% of the total litter amount was recorded), along the foreshore (7.8%), at the high tide water level (64.2%) and backshore area (25.8%). Litter was dominated by plastics and cloth, related to the activity of beachgoers and wastewater discharges at places close to rivers and tidal creeks mouths. Specific location and morphodynamic characteristics of each site, number of users and clean-up operations were important factors that determined the content of beach litter.

Analysis and Practice of Urban Wetland Construction Technology in Mining Subsidence Water Area

The mining of underground coal resources has a great impact on the ecological environment, especially in the high groundwater level area in the East, the mining subsidence has a more severe impact on the surface water, resulting in serious surface water, and the feasibility of restoring the original land function is poor. Based on the analysis of the characteristics of mining subsidence water, this paper puts forward the key technology of urban wetland construction, and analyzes it combined with engineering examples. The results show that: in the mining subsidence water area around the city, relying on the geographical advantages and abundant secondary wetland resources of coal mining subsidence, we can shape the regional tourism image, focus on the construction of Urban Wetland Park and ecological wetland, expand the urban service function of wetland in the aspects of leisure, tourism, education and tourism, as well as the rainwater storage and water purification function of wetland. This study provides a reference for the construction of similar mining cities.

Explaining Income-Related Inequalities in Dietary Knowledge: Evidence from the China Health and Nutrition Survey.

Lack of adequate dietary knowledge may result in poor health conditions. This study aims to measure income-related inequality in dietary knowledge, and to explain the sources of the inequality. Data were from the China Health and Nutrition Survey (CHNS) conducted in 2015. A summary of the dietary knowledge score and dietary guideline awareness was used to measure the dietary knowledge of respondents. The concentration index was employed as a measure of socioeconomic inequality and was decomposed into its determining factors. The study found that the proportion of respondents who correctly answered questions on dietary knowledge was significantly low for some questions. Compared to rural residents, urban residents had a higher proportion of correctly answered dietary knowledge questions. In addition, there are pro-rich inequalities in dietary knowledge. This observed inequality is determined not only by individual factors but also high-level area factors. Our study recommends that future dietary education programs could take different strategies for individuals with different educational levels and focus more on disadvantaged people. It would be beneficial to consider local dietary habits in developing education materials.