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  1. Article ; Online: On the intrinsic curvature of animal whiskers.

    Luo, Yifu / Hartmann, Mitra J Z

    PloS one

    2023  Volume 18, Issue 1, Page(s) e0269210

    Abstract: Facial vibrissae (whiskers) are thin, tapered, flexible, hair-like structures that are an important source of tactile sensory information for many species of mammals. In contrast to insect antennae, whiskers have no sensors along their lengths. Instead, ... ...

    Abstract Facial vibrissae (whiskers) are thin, tapered, flexible, hair-like structures that are an important source of tactile sensory information for many species of mammals. In contrast to insect antennae, whiskers have no sensors along their lengths. Instead, when a whisker touches an object, the resulting deformation is transmitted to mechanoreceptors in a follicle at the whisker base. Previous work has shown that the mechanical signals transmitted along the whisker will depend strongly on the whisker's geometric parameters, specifically on its taper (how diameter varies with arc length) and on the way in which the whisker curves, often called "intrinsic curvature." Although previous studies have largely agreed on how to define taper, multiple methods have been used to quantify intrinsic curvature. The present work compares and contrasts different mathematical approaches towards quantifying this important parameter. We begin by reviewing and clarifying the definition of "intrinsic curvature," and then show results of fitting whisker shapes with several different functions, including polynomial, fractional exponent, elliptical, and Cesàro. Comparisons are performed across ten species of whiskered animals, ranging from rodents to pinnipeds. We conclude with a discussion of the advantages and disadvantages of using the various models for different modeling situations. The fractional exponent model offers an approach towards developing a species-specific parameter to characterize whisker shapes within a species. Constructing models of how the whisker curves is important for the creation of mechanical models of tactile sensory acquisition behaviors, for studies of comparative evolution, morphology, and anatomy, and for designing artificial systems that can begin to emulate the whisker-based tactile sensing of animals.
    MeSH term(s) Animals ; Vibrissae/physiology ; Mammals/anatomy & histology ; Touch/physiology ; Touch Perception ; Caniformia
    Language English
    Publishing date 2023-01-06
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2267670-3
    ISSN 1932-6203 ; 1932-6203
    ISSN (online) 1932-6203
    ISSN 1932-6203
    DOI 10.1371/journal.pone.0269210
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  2. Article ; Online: Comparative morphology of the whiskers and faces of mice (Mus musculus) and rats (Rattus norvegicus).

    Bresee, Chris S / Belli, Hayley M / Luo, Yifu / Hartmann, Mitra J Z

    The Journal of experimental biology

    2023  Volume 226, Issue 19

    Abstract: Understanding neural function requires quantification of the sensory signals that an animal's brain evolved to interpret. These signals in turn depend on the morphology and mechanics of the animal's sensory structures. Although the house mouse (Mus ... ...

    Abstract Understanding neural function requires quantification of the sensory signals that an animal's brain evolved to interpret. These signals in turn depend on the morphology and mechanics of the animal's sensory structures. Although the house mouse (Mus musculus) is one of the most common model species used in neuroscience, the spatial arrangement of its facial sensors has not yet been quantified. To address this gap, the present study quantifies the facial morphology of the mouse, with a particular focus on the geometry of its vibrissae (whiskers). The study develops equations that establish relationships between the three-dimensional (3D) locations of whisker basepoints, whisker geometry (arclength, curvature) and the 3D angles at which the whiskers emerge from the face. Additionally, the positions of facial sensory organs are quantified relative to bregma-lambda. Comparisons with the Norway rat (Rattus norvegicus) indicate that when normalized for head size, the whiskers of these two species have similar spacing density. The rostral-caudal distances between facial landmarks of the rat are a factor of ∼2.0 greater than the mouse, while the scale of bilateral distances is larger and more variable. We interpret these data to suggest that the larger size of rats compared with mice is a derived (apomorphic) trait. As rodents are increasingly important models in behavioral neuroscience, the morphological model developed here will help researchers generate naturalistic, multimodal patterns of stimulation for neurophysiological experiments and allow the generation of synthetic datasets and simulations to close the loop between brain, body and environment.
    MeSH term(s) Rats ; Mice ; Animals ; Vibrissae/physiology ; Brain ; Touch/physiology
    Language English
    Publishing date 2023-10-12
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 218085-6
    ISSN 1477-9145 ; 0022-0949
    ISSN (online) 1477-9145
    ISSN 0022-0949
    DOI 10.1242/jeb.245597
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  3. Article ; Online: Constraints on the deformation of the vibrissa within the follicle.

    Luo, Yifu / Bresee, Chris S / Rudnicki, John W / Hartmann, Mitra J Z

    PLoS computational biology

    2021  Volume 17, Issue 4, Page(s) e1007887

    Abstract: Nearly all mammals have a vibrissal system specialized for tactile sensation, composed of whiskers growing from sensor-rich follicles in the skin. When a whisker deflects against an object, it deforms within the follicle and exerts forces on the ... ...

    Abstract Nearly all mammals have a vibrissal system specialized for tactile sensation, composed of whiskers growing from sensor-rich follicles in the skin. When a whisker deflects against an object, it deforms within the follicle and exerts forces on the mechanoreceptors inside. In addition, during active whisking behavior, muscle contractions around the follicle and increases in blood pressure in the ring sinus will affect the whisker deformation profile. To date, however, it is not yet possible to experimentally measure how the whisker deforms in an intact follicle or its effects on different groups of mechanoreceptors. The present study develops a novel model to predict vibrissal deformation within the follicle sinus complex. The model is based on experimental results from a previous ex vivo study on whisker deformation within the follicle, and on a new histological analysis of follicle tissue. It is then used to simulate whisker deformation within the follicle during passive touch and active whisking. Results suggest that the most likely whisker deformation profile is "S-shaped," crossing the midline of the follicle right below the ring sinus. Simulations of active whisking indicate that an increase in overall muscle stiffness, an increase in the ratio between deep and superficial intrinsic muscle stiffness, and an increase in sinus blood pressure will all enhance tactile sensitivity. Finally, we discuss how the deformation profiles might map to the responses of primary afferents of each mechanoreceptor type. The mechanical model presented in this study is an important first step in simulating mechanical interactions within whisker follicles.
    MeSH term(s) Animals ; Female ; Hair Follicle/anatomy & histology ; Hair Follicle/physiology ; Mechanoreceptors/physiology ; Physical Stimulation ; Rats ; Rats, Long-Evans ; Touch Perception/physiology ; Vibrissae/physiology
    Language English
    Publishing date 2021-04-01
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2193340-6
    ISSN 1553-7358 ; 1553-734X
    ISSN (online) 1553-7358
    ISSN 1553-734X
    DOI 10.1371/journal.pcbi.1007887
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  4. Article ; Online: Relative contributions of natural and anthropogenic factors to the distribution patterns of nature reserves in mainland China.

    Zhao, Ting / Miao, Congke / Wang, Jing / Su, Pinjie / Chu, Kuo / Luo, Yifu / Sun, Qiqi / Yao, Yanzhong / Song, Youtao / Bu, Naishun

    The Science of the total environment

    2022  Volume 847, Page(s) 157449

    Abstract: Nature reserves (NRs) are designated as a result of the ecosystem, species, economy, population, and land use coordination. However, the extent to which these factors influence the geographical pattern of NRs is unclear. Here, 11 indices (seven natural ... ...

    Abstract Nature reserves (NRs) are designated as a result of the ecosystem, species, economy, population, and land use coordination. However, the extent to which these factors influence the geographical pattern of NRs is unclear. Here, 11 indices (seven natural and four anthropogenic) were examined to identify these relationships in over 2600 terrestrial NRs in mainland China at the provincial level. Correlation analysis between natural and anthropogenic factors and NRs showed that desert and grassland had a positive correlation with NR coverage and area, and a negative correlation with NR density. This result was reversed in the correlation analysis between forest wetland coverage, endangered species, wildlife and NR coverage, area, and density. Similar results were found in the correlation analysis of all anthropogenic factors (population density, agricultural land, roads, and per capita GDP) with the coverage, area, and density of NRs. Canonical correspondence analysis (CCA) showed that three significant natural indicators (desert ecosystems, grasslands ecosystems, and forested and wetlands ecosystems) could explain 64.2 % of the pattern of NRs. The largest contributor was desert coverage, explaining 48.3 % (P = 0.002) of all indicators, followed by grassland coverage, explaining 8.6 % (P = 0.012), and forest and wetland coverage, explaining 7.3 % (P = 0.008). Human activities were significantly positively correlated with forest and wetland coverage, flora, and fauna, and negatively correlated with desert and grassland coverage. Compared with sand and grassland in the western region, the forest wetlands and wildlife in the eastern and central provinces were under greater pressure from anthropogenic activities. Therefore, natural factors determine the general layout of NRs, while the influence of anthropogenic activities makes the distribution of NRs patchy. When establishing national parks, governments must design strategies to coordinate areas with high biodiversity and high levels of human activity.
    MeSH term(s) Animals ; Animals, Wild ; Anthropogenic Effects ; Biodiversity ; China ; Conservation of Natural Resources/methods ; Ecosystem ; Grassland ; Humans ; Sand
    Chemical Substances Sand
    Language English
    Publishing date 2022-07-18
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 121506-1
    ISSN 1879-1026 ; 0048-9697
    ISSN (online) 1879-1026
    ISSN 0048-9697
    DOI 10.1016/j.scitotenv.2022.157449
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  5. Article ; Online: Source analysis of the tropospheric NO

    Liu, Feng / Xing, Chengzhi / Su, Pinjie / Luo, Yifu / Zhao, Ting / Xue, Jiexiao / Zhang, Guohui / Qin, Sida / Song, Youtao / Bu, Naishun

    Environmental pollution (Barking, Essex : 1987)

    2022  Volume 306, Page(s) 119424

    Abstract: Ground-based Multi-Axis Differential Optical Absorption Spectroscopy (Max-DOAS) measurements of nitrogen dioxide ( ... ...

    Abstract Ground-based Multi-Axis Differential Optical Absorption Spectroscopy (Max-DOAS) measurements of nitrogen dioxide (NO
    MeSH term(s) Air Pollutants/analysis ; China ; Coal/analysis ; Environmental Monitoring/methods ; Nitrogen Dioxide/analysis ; Seasons
    Chemical Substances Air Pollutants ; Coal ; Nitrogen Dioxide (S7G510RUBH)
    Language English
    Publishing date 2022-05-07
    Publishing country England
    Document type Journal Article
    ZDB-ID 280652-6
    ISSN 1873-6424 ; 0013-9327 ; 0269-7491
    ISSN (online) 1873-6424
    ISSN 0013-9327 ; 0269-7491
    DOI 10.1016/j.envpol.2022.119424
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  6. Article: Relative contributions of natural and anthropogenic factors to the distribution patterns of nature reserves in mainland China

    Zhao, Ting / Miao, Congke / Wang, Jing / Su, Pinjie / Chu, Kuo / Luo, Yifu / Sun, Qiqi / Yao, Yanzhong / Song, Youtao / Bu, Naishun

    Science of the total environment. 2022 July 13,

    2022  

    Abstract: Nature reserves (NRs) are designated as a result of the ecosystem, species, economy, population, and land use coordination. However, the extent to which these factors influence the geographical pattern of NRs is unclear. Here, 11 indices (seven natural ... ...

    Abstract Nature reserves (NRs) are designated as a result of the ecosystem, species, economy, population, and land use coordination. However, the extent to which these factors influence the geographical pattern of NRs is unclear. Here, 11 indices (seven natural and four anthropogenic) were examined to identify these relationships in over 2400 terrestrial NRs in mainland China at the provincial level. Correlation analysis between natural and anthropogenic factors and NRs showed that desert and grassland had a positive correlation with NR coverage and area, and a negative correlation with NR density. This result was reversed in the correlation analysis between forest wetland coverage, endangered species, wildlife and NR coverage, area, and density. Similar results were found in the correlation analysis of all anthropogenic factors (population density, agricultural land, roads, and per capita GDP) with the coverage, area, and density of NRs. Canonical correspondence analysis (CCA) showed that three significant natural indicators (desert ecosystems, grasslands ecosystems, and forested and wetlands ecosystems) could explain 64.2 % of the pattern of NRs. The largest contributor was desert coverage, explaining 48.3 % (P = 0.002) of all indicators, followed by grassland coverage, explaining 8.6 % (P = 0.012), and forest and wetland coverage, explaining 7.3 % (P = 0.008). Human activities were significantly positively correlated with forest and wetland coverage, flora, and fauna, and negatively correlated with desert and grassland coverage. Compared with sand and grassland in the western region, the forest wetlands and wildlife in the eastern and central provinces were under greater pressure from anthropogenic activities. Therefore, natural factors determine the general layout of NRs, while the influence of anthropogenic activities makes the distribution of NRs patchy. When establishing national parks, governments must design strategies to coordinate areas with high biodiversity and high levels of human activity.
    Keywords agricultural land ; biodiversity ; correspondence analysis ; ecosystems ; environment ; fauna ; flora ; forests ; grasslands ; humans ; land use ; population density ; sand ; wetlands ; wildlife ; China
    Language English
    Dates of publication 2022-0713
    Publishing place Elsevier B.V.
    Document type Article
    Note Pre-press version
    ZDB-ID 121506-1
    ISSN 1879-1026 ; 0048-9697
    ISSN (online) 1879-1026
    ISSN 0048-9697
    DOI 10.1016/j.scitotenv.2022.157449
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  7. Article: Identification of ozone sensitivity for NO2 and secondary HCHO based on MAX-DOAS measurements in northeast China

    Xue, Jiexiao / Zhao, Ting / Luo, Yifu / Miao, Congke / Su, Pinjie / Liu, Feng / Zhang, Guohui / Qin, Sida / Song, Youtao / Bu, Naishun / Xing, Chengzhi

    Environment international. 2022 Feb., v. 160

    2022  

    Abstract: In this study, tropospheric formaldehyde (HCHO) vertical column densities (VCDs) were measured using multi-axis differential optical absorption spectroscopy (MAX-DOAS) from January to November 2019 in Shenyang, Northeast China. The maximum HCHO VCD value ...

    Abstract In this study, tropospheric formaldehyde (HCHO) vertical column densities (VCDs) were measured using multi-axis differential optical absorption spectroscopy (MAX-DOAS) from January to November 2019 in Shenyang, Northeast China. The maximum HCHO VCD value appeared in the summer (1.74 × 10¹⁶ molec/cm²), due to increased photo-oxidation of volatile organic compounds (VOCs). HCHO concentrations increased from 08:00 and peaked near 13:00, which was mainly attributed to the increased release of isoprene from plants and enhanced photolysis at noon. The HCHO VCDs observed by MAX-DOAS and OMI have a good correlation coefficient (R) of 0.78, and the contributions from primary and secondary HCHO sources were distinguished by the multi-linear regression model. The anthropogenic emissions showed unobvious seasonal variations, and the primary HCHO was relatively stable in Shenyang. Secondary HCHO contributed 82.62%, 83.90%, 78.90%, and 41.53% to the total measured ambient HCHO during the winter, spring, summer, and autumn, respectively. We also found a good correlation (R = 0.78) between enhanced vegetation index (EVI) and HCHO VCDs, indicating that the oxidation of biogenic volatile organic compounds (BVOCs) was the main source of HCHO. The ratio of secondary HCHO to nitrogen dioxide (NO₂) was used as the tracer to analyze O₃-NOₓ-VOC sensitivities. We found that the VOC-limited, VOC-NOₓ-limited, and NOₓ-limited regimes made up 93.67%, 6.23%, 0.11% of the overall measurements, respectively. In addition, summertime ozone (O₃) sensitivity changed from VOC-limited in the morning to VOC-NOₓ-limited in the afternoon. Therefore, this study offers information on HCHO sources and corresponding O₃ production sensitivities to support strategic management decisions.
    Keywords autumn ; environment ; formaldehyde ; isoprene ; nitrogen dioxide ; ozone ; photolysis ; photooxidation ; regression analysis ; spectroscopy ; spring ; summer ; troposphere ; vegetation index ; volatile organic compounds ; winter ; China
    Language English
    Dates of publication 2022-02
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 554791-x
    ISSN 1873-6750 ; 0160-4120
    ISSN (online) 1873-6750
    ISSN 0160-4120
    DOI 10.1016/j.envint.2021.107048
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  8. Article: Source analysis of the tropospheric NO2 based on MAX-DOAS measurements in northeastern China

    Liu, Feng / Xing, Chengzhi / Su, Pinjie / Luo, Yifu / Zhao, Ting / Xue, Jiexiao / Zhang, Guohui / Qin, Sida / Song, Youtao / Bu, Naishun

    Environmental pollution. 2022 Aug. 01, v. 306

    2022  

    Abstract: Ground-based Multi-Axis Differential Optical Absorption Spectroscopy (Max-DOAS) measurements of nitrogen dioxide (NO₂) were continuously obtained from January to November 2019 in northeastern China (NEC). Seasonal variations in the mean NO₂ vertical ... ...

    Abstract Ground-based Multi-Axis Differential Optical Absorption Spectroscopy (Max-DOAS) measurements of nitrogen dioxide (NO₂) were continuously obtained from January to November 2019 in northeastern China (NEC). Seasonal variations in the mean NO₂ vertical column densities (VCDs) were apparent, with a maximum of 2.9 × 10¹⁶ molecules cm⁻² in the winter due to enhanced NO₂ emissions from coal-fired winter heating, a longer photochemical lifetime and atmospheric transport. Daily maximum and minimum NO₂ VCDs were observed, independent of the season, at around 11:00 and 13:00 local time, respectively, and the most obvious increases and decreases occurred in the winter and autumn, respectively. The mean diurnal NO₂ VCDs at 11:00 increased to at 08:00 by 1.6, 5.8, and 6.7 × 10¹⁵ molecules cm⁻² in the summer, autumn and winter, respectively, due to increased NO₂ emissions, and then decreased by 2.8, 4.2, and 5.1 × 10¹⁵ molecules cm⁻² at 13:00 in the spring, summer, and autumn, respectively. This was due to strong solar radiation and increased planetary boundary layer height. There was no obvious weekend effect, and the NO₂ VCDs only decreased by about 10% on the weekends. We evaluated the contributions of emissions and transport in the different seasons to the NO₂ VCDs using a generalized additive model, where the contributions of local emissions to the total in the spring, summer, autumn, and winter were 89 ± 12%, 92 ± 11%, 86 ± 12%, and 72 ± 16%, respectively. The contribution of regional transport reached 26% in the winter, and this high contribution value was mainly correlated with the northeast wind, which was due to the transport channel of air pollutants along the Changbai Mountains in NEC. The NO₂/SO₂ ratio was used to identify NO₂ from industrial sources and vehicle exhaust. The contribution of industrial NO₂ VCD sources was >66.3 ± 16% in Shenyang due to the large amount of coal combustion from heavy industrial activity, which emitted large amounts of NO₂. Our results suggest that air quality management in Shenyang should consider reductions in local NO₂ emissions from industrial sources along with regional cooperative control.
    Keywords air ; air quality ; autumn ; coal ; combustion ; heat ; models ; nitrogen dioxide ; photochemistry ; solar radiation ; spectroscopy ; spring ; summer ; troposphere ; wind ; winter ; China
    Language English
    Dates of publication 2022-0801
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 280652-6
    ISSN 1873-6424 ; 0013-9327 ; 0269-7491
    ISSN (online) 1873-6424
    ISSN 0013-9327 ; 0269-7491
    DOI 10.1016/j.envpol.2022.119424
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  9. Article: Hierarchical and cascading changes in the functional traits of soil animals induced by microplastics: A meta-analysis

    Su, Pinjie / Wang, Jing / Zhang, Dan / Chu, Kuo / Yao, Yanzhong / Sun, Qiqi / Luo, Yifu / Zhang, Runjie / Su, Xuping / Wang, Zichao / Bu, Naishun / Li, Zhaolei

    Journal of hazardous materials. 2022 Oct. 15, v. 440

    2022  

    Abstract: Given the immense quantities of plastics in the environments worldwide, it is inevitable that soil animals are exposed to microplastics. However, a comprehensive elucidation of the cascading responses of different levels of functional traits in soil ... ...

    Abstract Given the immense quantities of plastics in the environments worldwide, it is inevitable that soil animals are exposed to microplastics. However, a comprehensive elucidation of the cascading responses of different levels of functional traits in soil animals to microplastics remains unclear. A meta-analysis based on 80 published studies was conducted to quantify the hierarchical changes in soil animal traits from genes to survival under microplastics exposure. Soil animals substantially increased (by 62.1%) reactive oxygen species (ROS), copies of antioxidant genes increased by 35.7%, and antioxidant enzyme activities increased by 11.5% under the threat of microplastics. Unfortunately, the antioxidant responses did not completely eradicate the increased ROS. Animal traits at behavioral and survival levels were consequently significantly decreased (e.g., movement capacities, reproduction rate, growth rate, and survival rate decreased by 22.7%, 12.8%, 7.5%, and 3.1%, respectively). Microfauna endured more severe damage by microplastics due to higher ROS (63.7%) than macrofauna (33.5%). Additionally, round microplastics typically caused severe damage to soil animal survival rate that was inhibited by 16.6%. This study aimed to quantify the cascading responses of soil animal functional traits at multiple levels to microplastics, which will provide a comprehensive perspective for assessing the toxicities of microplastics in soil environments.
    Keywords animals ; antioxidant enzymes ; fauna ; meta-analysis ; microplastics ; reactive oxygen species ; reproduction ; soil ; survival rate
    Language English
    Dates of publication 2022-1015
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 1491302-1
    ISSN 1873-3336 ; 0304-3894
    ISSN (online) 1873-3336
    ISSN 0304-3894
    DOI 10.1016/j.jhazmat.2022.129854
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  10. Article ; Online: A Carbazole-Functionalized Porous Aromatic Framework for Enhancing Volatile Iodine Capture via

    Yan, Zhuojun / Cui, Bo / Zhao, Ting / Luo, Yifu / Zhang, Hongcui / Xie, Jialin / Li, Na / Bu, Naishun / Yuan, Ye / Xia, Lixin

    Molecules (Basel, Switzerland)

    2021  Volume 26, Issue 17

    Abstract: Nitrogen-rich porous networks with additional polarity and basicity may serve as effective adsorbents for ... ...

    Abstract Nitrogen-rich porous networks with additional polarity and basicity may serve as effective adsorbents for the
    Language English
    Publishing date 2021-08-30
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 1413402-0
    ISSN 1420-3049 ; 1431-5165 ; 1420-3049
    ISSN (online) 1420-3049
    ISSN 1431-5165 ; 1420-3049
    DOI 10.3390/molecules26175263
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