•Photosynthetic and non-photosynthetic forest canopy components are successfully separated.•A point is converted into a surface area by considering sampling spacing and incident angle of laser ...beam.•TLS-based woody-to-total area ratio method has been successfully developed and validated.
Accurately determining woody-to-total area ratio (WTA) is a key step to indirectly retrieve leaf area index (LAI) from terrestrial laser scanning (TLS) data. In this work, we first collected both individual tree and forest plot point cloud data (PCD) from broadleaf and coniferous tree species and leaf characteristics using both side-lateral and full field-of-view TLS field setups with scan distances between 2.5 to 28m. Using a local geometrical feature-based algorithm, the generated PCD were automatically classified into three different categories including photosynthetic canopy components, non-photosynthetic canopy components, and bare earth. To convert each classified point into a surface area, we then developed and validated a novel approach that considers sampling space, laser incidence angle, and leaf orientation information. The estimated surface areas from this approach showed strong agreements with validation datasets for single leaf (91.44%), photosynthetic (95.64%), and non-photosynthetic canopy components (89.60%) of an artificial tree and stems of an old-growth coniferous tree (93.53%), two individual broadleaf trees (98.31% and 97.46%) and a broadleaf forest plot (90.26%). By doing this, we computed the parameter WTA for an individual artificial tree (10.90%), an old-growth coniferous tree (29.97%), two individual broadleaf tree (14.83% and 4.27%) and four natural forest stands ranging from 7.74%–15.57%, respectively. The proposed method can effectively improve the accuracy of retrieving true LAI by removing the effects of woody components and converting each point into a surface area.
Indoor exposure to heavy metals poses human health risks worldwide, but study reports from Thailand are still limited, particularly in rural and urban areas. We measured the heavy metals in a hundred ...indoor household dust samples collected from urban and rural areas in Chiang Mai and Lamphun provinces and found a significantly higher concentration of As in rural areas and Cd in urban areas with industrial activities. The source identification of the heavy metals showed significant enrichment from traffic emissions, paint, smoking, and mixed sources with natural soil. From health risk assessment models, children were more vulnerable to noncarcinogenic risks (HI = 1.45), primarily via ingestion (HQ = 1.39). Lifetime cancer risks (LCRs) due to heavy metal exposure were found in adults (LCR = 5.31 × 10
) and children (LCR = 9.05 × 10
). The cancer risks from As were higher in rural areas via ingestion, while Cr and Ni were higher in urban areas via inhalation and ingestion, respectively. This study estimated that approximately 5 out of 10,000 adults and 9 out of 10,000 children among the population may develop cancer in their lifetime from exposure to indoor heavy metals in this region.
Urban spatial interaction integrates cities into closely related urban network systems in continuous urban regions. However, it also brings differentiation and has mutual negative impacts between ...each location. Unbalanced development is one such impacts and needs closely monitoring. The housing vacancy rate (HVR) in a continuous urban region is an important index in the unbalanced development of a continuous urban region since it indicates the uneven distribution of population and investment across cities. This study uses NPP-VIIRS NTL data and Landsat 8 OLT images to estimate HVRs at the district level. Additionally, this study tracks the spatial–temporal dynamics of HVR distributions in the Pearl River Delta (PRD) region. The comparison between the sampled HVRs and estimated HVRs verifies the effectiveness of the estimated HVRs in identifying dynamic changes in HVRs. This study has found that although overall decreasing HVRs are observed in the PRD, speculations and irrational real estate investment exist in cities on the west bank of the Pearl River Estuary and in some isolated districts in other cities. Furthermore, increasing proportions of vacant pixels in most cities indicate rising real estate development, requiring further supervision. This study suggests that more precise data and advanced techniques could help to improve the accuracy of the estimation techniques.
We are able to temporally organize multiple movements in a purposeful manner in everyday life. Both the dorsal premotor (PMd) area and pre-supplementary motor area (pre-SMA) are known to be involved ...in the performance of motor sequences. However, it is unclear how each area differentially contributes to controlling multiple motor sequences. To address this issue, we recorded single-unit activity in both areas while monkeys (one male, one female) performed sixteen motor sequences. Each sequence comprised either a series of two identical movements (repetition) or two different movements (nonrepetition). The sequence was initially instructed with visual signals but had to be remembered thereafter. Here, we showed that the activity of single neurons in both areas transitioned from reactive- to predictive encoding while motor sequences were memorized. In the memory-guided trials, in particular, the activity of PMd cells preferentially represented the second movement (2M) in the sequence leading to a reward generally regardless of the first movement (1M). Such activity frequently began even before the 1M in a prospective manner, and was enhanced in nonrepetition sequences. Behaviorally, a lack of the activity enhancement often resulted in premature execution of the 2M. In contrast, cells in pre-SMA instantiated particular sequences of actions by coordinating switching or nonswitching movements in sequence. Our findings suggest that PMd and pre-SMA play complementary roles within behavioral contexts: PMd preferentially controls the movement that leads to a reward rather than the sequence per se, whereas pre-SMA coordinates all elements in a sequence by integrating temporal orders of multiple movements.
Although both dorsal premotor (PMd) area and pre-supplementary motor area (pre-SMA) are involved in the control of motor sequences, it is not clear how these two areas contribute to coordination of sequential movements differently. To address this issue, we directly compared neuronal activity in the two areas recorded while monkeys memorized and performed multiple motor sequences. Our findings suggest that PMd preferentially controls the final action that ultimately leads to a reward in a prospective manner, whereas the pre-SMA coordinates switching among multiple actions within the context of the sequence. Our findings are of significance to understand the distinct roles for motor-related areas in the planning and executing motor sequences and the pathophysiology of apraxia and/or Parkinson's diseases that disables skilled motor actions.
Microtubule affinity-regulating kinase 4 (MARK4) has recently been identified as a potential drug target for several complex diseases including cancer, diabetes and neurodegenerative disorders. ...Inhibition of MARK4 activity is an appealing therapeutic option to treat such diseases. Here, we have performed structure-based virtual high-throughput screening of 100,000 naturally occurring compounds from ZINC database against MARK4 to find its potential inhibitors. The resulted hits were selected, based on the binding affinities, docking scores and selectivity. Further, binding energy calculation, Lipinski filtration and ADMET prediction were carried out to find safe and better hits against MARK4. Best 10 compounds bearing high specificity and binding efficiency were selected, and their binding pattern to MARK4 was analyzed in detail. Finally, 100 ns molecular dynamics simulation was performed to evaluate; the dynamics stability of MARK4-compound complex. In conclusion, these selected natural compounds from ZINC database might be potential leads against MARK4, and can further be exploited in drug design and development for associated diseases.
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